1 00:00:06,414 --> 00:00:08,149 >> WELCOME, EVERYONE, TO THE 2 00:00:08,149 --> 00:00:09,584 COVID-19 SCIENTIFIC INTEREST 3 00:00:09,584 --> 00:00:11,786 GROUP SEMINAR SERIES. 4 00:00:11,786 --> 00:00:14,188 OUR SPEAKER TODAY IS MICHAEL 5 00:00:14,188 --> 00:00:15,056 LETKO, ASSISTANT PROFESSOR PAUL 6 00:00:15,056 --> 00:00:18,326 G ALLEN SCHOOL OF GLOBAL HEALTH, 7 00:00:18,326 --> 00:00:20,628 WASHINGTON STATE UNIVERSITY. 8 00:00:20,628 --> 00:00:22,697 HIS RESEARCH FOCUSES ON 9 00:00:22,697 --> 00:00:24,665 UNDERSTANDING ECOLOGICAL VIROME 10 00:00:24,665 --> 00:00:27,001 AND ASSESSING POTENTIAL FOR 11 00:00:27,001 --> 00:00:29,503 VIRUS ZOONOSIS TO HUMANS. 12 00:00:29,503 --> 00:00:30,571 PRIOR TO STARTING HIS OWN LAB, 13 00:00:30,571 --> 00:00:33,240 MICHAEL WAS A POSTDOC AT THE 14 00:00:33,240 --> 00:00:35,743 ROCKY MOUNTAIN LABS WHERE HE 15 00:00:35,743 --> 00:00:36,944 STUDIED BETA CORONAVIRUSES WITH 16 00:00:36,944 --> 00:00:40,982 POTENTIAL TO EMERGE IN HUMANS. 17 00:00:40,982 --> 00:00:44,819 IN 2020 PUBLISHED A PAPER 18 00:00:44,819 --> 00:00:46,687 DEMONSTRATING NEWLY DESCRIBED 19 00:00:46,687 --> 00:00:48,322 SARS-COV-2 ACE-2 RECEPTOR, AND 20 00:00:48,322 --> 00:00:49,957 MADE THAT DISCOVERY USING 21 00:00:49,957 --> 00:00:50,825 FUNCTIONAL VIROMIC STRATEGY HE 22 00:00:50,825 --> 00:00:54,462 WILL INTRODUCE TO US TODAY. 23 00:00:54,462 --> 00:00:59,367 TODAY HE WILL TELL US ABOUT HIS 24 00:00:59,367 --> 00:01:03,638 CONTAINMENT EFFORTS TO SURVEY 25 00:01:03,638 --> 00:01:05,506 USE BY BETA CORONAVIRUSES TO 26 00:01:05,506 --> 00:01:06,941 PREDICT THE NEXT WITH PANDEMIC 27 00:01:06,941 --> 00:01:07,208 POTENTIAL. 28 00:01:07,208 --> 00:01:11,879 FOR THE AUDIENCE MEMBERS WHO 29 00:01:11,879 --> 00:01:14,281 WOULD LIKE TO ASK A QUESTION USE 30 00:01:14,281 --> 00:01:18,419 THE "SEND LIVE FEEDBACK" BUTTON 31 00:01:18,419 --> 00:01:19,987 THROUGH THE NIH VIDEOCAST 32 00:01:19,987 --> 00:01:20,955 APPROVE THE DESCRIPTIVE 33 00:01:20,955 --> 00:01:21,222 PARAGRAPH. 34 00:01:21,222 --> 00:01:23,124 LEAVE YOUR COMMENTS AT ANY POINT 35 00:01:23,124 --> 00:01:23,791 DURING THE TALK. 36 00:01:23,791 --> 00:01:27,094 WE'LL HAVE A FEW MINUTES TO DO A 37 00:01:27,094 --> 00:01:28,295 Q&A WITH MICHAEL AFTERWARDS. 38 00:01:28,295 --> 00:01:32,867 SO WITH THAT, I WANT TO THANK 39 00:01:32,867 --> 00:01:34,301 MICHAEL FOR JOINING US, WE LOOK 40 00:01:34,301 --> 00:01:44,478 FORWARD TO YOUR TALK. 41 00:01:44,478 --> 00:01:45,312 MICHAEL, YOU ARE -- 42 00:01:45,312 --> 00:01:46,113 >> THERE WE GO. 43 00:01:46,113 --> 00:01:47,782 THANK YOU FOR HAVING ME. 44 00:01:47,782 --> 00:01:51,252 JUST TO GET RIGHT INTO IT, THIS 45 00:01:51,252 --> 00:01:56,090 WORK STARTED MANY YEARS AGO NOW, 46 00:01:56,090 --> 00:01:58,626 FOR ME STARTED AROUND 2018, BUT 47 00:01:58,626 --> 00:02:03,431 REALLY THE PROBLEM THAT WE'RE 48 00:02:03,431 --> 00:02:04,965 DISCUSSING IS A LONG-RUNNING 49 00:02:04,965 --> 00:02:06,500 PROGRAM IN VIRAL, SARS EMERGED 50 00:02:06,500 --> 00:02:09,670 IN 2003, TRACED BACK INTO ANIMAL 51 00:02:09,670 --> 00:02:11,439 MARKETS, SHORTLY THEREAFTER WAS 52 00:02:11,439 --> 00:02:14,275 FOUND IN BATS OR VIRUSES CLOSELY 53 00:02:14,275 --> 00:02:17,678 RELATED TO SARS WERE FOUND IN 54 00:02:17,678 --> 00:02:18,379 BATS. 55 00:02:18,379 --> 00:02:20,414 AND REALLY SINCE THEN, THERE'S 56 00:02:20,414 --> 00:02:22,616 WILL BE THIS KIND OF EXPLOSION 57 00:02:22,616 --> 00:02:25,119 OF VIRUS DISCOVERY RESEARCH THAT 58 00:02:25,119 --> 00:02:30,591 HAS KIND OF COME ALONGSIDE THE 59 00:02:30,591 --> 00:02:32,126 NEXT GENERATION SEQUENCING 60 00:02:32,126 --> 00:02:33,194 TECHNOLOGY GROWING SINCE THE 61 00:02:33,194 --> 00:02:34,729 FIRST TIME SARS SPILLED INTO THE 62 00:02:34,729 --> 00:02:36,497 HUMAN POPULATION. 63 00:02:36,497 --> 00:02:38,999 THIS HAS LED TO A MOUNTAIN OF 64 00:02:38,999 --> 00:02:41,302 DATA BASICALLY ABOUT DIFFERENT 65 00:02:41,302 --> 00:02:43,938 VIRUSES, CORONAVIRUSES FOUND IN 66 00:02:43,938 --> 00:02:44,805 DIFFERENT ANIMAL SPECIES, 67 00:02:44,805 --> 00:02:48,642 BASICALLY ALL CORNERS OF THE 68 00:02:48,642 --> 00:02:49,276 WORLD. 69 00:02:49,276 --> 00:02:51,378 SO, IT'S JUST THIS LARGE PILE OF 70 00:02:51,378 --> 00:02:51,612 DATA. 71 00:02:51,612 --> 00:02:54,448 AND I MADE THIS SLIDE BEFORE THE 72 00:02:54,448 --> 00:02:56,183 COVID-19 OUTBREAK, SO YOU CAN 73 00:02:56,183 --> 00:02:58,285 IMAGINE THIS HAS GOTTEN EVEN 74 00:02:58,285 --> 00:02:59,854 MORE EXPANSIVE SINCE THIS POINT. 75 00:02:59,854 --> 00:03:01,889 BUT REALLY FOR MOST OF THESE 76 00:03:01,889 --> 00:03:03,858 STUDIES THERE'S NOT A LOT OF 77 00:03:03,858 --> 00:03:04,492 FOLLOW-UP AFTER THE SEQUENCING 78 00:03:04,492 --> 00:03:05,726 IS DONE. 79 00:03:05,726 --> 00:03:16,270 SO WE CAN DO FILE PHYLOGENETIC 80 00:03:19,807 --> 00:03:20,875 ANALYSIS, CAN THEY TRANSMIT TO 81 00:03:20,875 --> 00:03:22,143 HUMANS, DO THEY HAVE POTENTIAL 82 00:03:22,143 --> 00:03:25,079 TO SPILL INTO OTHER ANIMALS, 83 00:03:25,079 --> 00:03:27,081 WHAT DISEASE MIGHT THEY CAUSE? 84 00:03:27,081 --> 00:03:29,683 AND SO LOOK AT THIS QUESTION A 85 00:03:29,683 --> 00:03:32,086 LITTLE MORE VISUALLY, LIVE 86 00:03:32,086 --> 00:03:32,720 VIRUSES CIRCULATE IN ANIMALS AT 87 00:03:32,720 --> 00:03:33,187 THE MOMENT. 88 00:03:33,187 --> 00:03:37,458 BUT THESE ARE NOT USUALLY 89 00:03:37,458 --> 00:03:38,559 ISOLATED BECAUSE WHEN YOU'RE 90 00:03:38,559 --> 00:03:39,860 SAMPLING HUNDREDS OF ANIMALS IN 91 00:03:39,860 --> 00:03:43,063 THESE STUDIES IT'S NOT ALWAYS 92 00:03:43,063 --> 00:03:44,231 FEASIBLE TO, YOU KNOW, TO KEEP 93 00:03:44,231 --> 00:03:46,567 YOUR SAMPLES IN A WAY THAT WOULD 94 00:03:46,567 --> 00:03:49,837 ALLOW YOU TO RECOVER LIVE VIRUS 95 00:03:49,837 --> 00:03:51,806 FOR SAFETY REASONS, FOR LOGISTIC 96 00:03:51,806 --> 00:03:52,273 REASONS. 97 00:03:52,273 --> 00:03:54,108 OFTENTIMES WE'RE TRYING TO GET 98 00:03:54,108 --> 00:03:55,309 SAMPLES OUT OF DIFFERENT 99 00:03:55,309 --> 00:03:59,046 COUNTRIES, SO IT'S EASIER TO PUT 100 00:03:59,046 --> 00:04:00,981 THEM IN BUFFERS AND DO GENETIC 101 00:04:00,981 --> 00:04:05,052 SEQUENCING ON SAMPLES. 102 00:04:05,052 --> 00:04:06,487 NEXT GENERATION SEQUENCING 103 00:04:06,487 --> 00:04:08,355 ALLOWS A SCALABLE APPROACH, 104 00:04:08,355 --> 00:04:11,525 UNBIASED TO GET WHOLE GENOME 105 00:04:11,525 --> 00:04:12,293 SEQUENCES NOW OF VIRUSES, 106 00:04:12,293 --> 00:04:14,795 BASICALLY ALL THE VIRUSES IN THE 107 00:04:14,795 --> 00:04:15,162 SAMPLE. 108 00:04:15,162 --> 00:04:16,897 SO WHEN I STARTED THIS WORK 109 00:04:16,897 --> 00:04:19,767 THERE WERE 17 YEARS OF VIRUS 110 00:04:19,767 --> 00:04:24,438 DISCOVERY, AND WE HAD ABOUT 200 111 00:04:24,438 --> 00:04:29,810 VIRAL RELATIVES IDENTIFIED FOR 112 00:04:29,810 --> 00:04:32,246 SARS-COV-1 ACROSS BATS IN ASIA. 113 00:04:32,246 --> 00:04:35,950 WE HAD 12 VIRUSES ACTUALLY 114 00:04:35,950 --> 00:04:37,952 ISOLATED OR CONSTRUCTED THROUGH 115 00:04:37,952 --> 00:04:40,020 REVERSE GENETICS IN THE LAB, 116 00:04:40,020 --> 00:04:41,989 VERY LITTLE DATA FOR MOST 117 00:04:41,989 --> 00:04:43,958 VIRUSES RELATED CLOSELY TO ONE 118 00:04:43,958 --> 00:04:48,996 WE KNOW HAD OBVIOUS PANDEMIC 119 00:04:48,996 --> 00:04:49,530 POTENTIAL. 120 00:04:49,530 --> 00:04:51,498 SO, ONLY ABOUT FIVE WERE 121 00:04:51,498 --> 00:04:51,966 ISOLATED THOUGH. 122 00:04:51,966 --> 00:04:54,368 SO REALLY HOW DO WE STUDY THINGS 123 00:04:54,368 --> 00:04:56,670 WE DON'T HAVE VIRAL SAMPLES FOR 124 00:04:56,670 --> 00:04:58,973 IN THE LABORATORY AND CAN WE DO 125 00:04:58,973 --> 00:04:59,940 MORE OF THEM? 126 00:04:59,940 --> 00:05:02,443 SO THIS GETS TO THE QUESTION OF 127 00:05:02,443 --> 00:05:03,878 REVERSE GENETICS, BUILDING A 128 00:05:03,878 --> 00:05:06,180 VIRUS FROM, YOU KNOW, BASICALLY 129 00:05:06,180 --> 00:05:08,349 FROM NOTHING. 130 00:05:08,349 --> 00:05:10,517 THE CORONAVIRUS GENOME IS 131 00:05:10,517 --> 00:05:14,255 ARRANGED IN THIS SERIES OF NOW 132 00:05:14,255 --> 00:05:15,923 WELL-CHARACTERIZED GENES THAT 133 00:05:15,923 --> 00:05:18,525 MAKE UP DIFFERENT ASPECTS OF THE 134 00:05:18,525 --> 00:05:20,594 VIRUS INVOLVED IN DIFFERENT 135 00:05:20,594 --> 00:05:21,061 BIOLOGICAL PROCESSES. 136 00:05:21,061 --> 00:05:21,929 YOU KNOW, WHILE WE HAVE ALL 137 00:05:21,929 --> 00:05:23,664 THESE GENES THE ONE WE'RE MOST 138 00:05:23,664 --> 00:05:25,532 INTERESTED IN IS THE SPIKE GENE 139 00:05:25,532 --> 00:05:27,601 BECAUSE YOU CAN SEE FROM HERE 140 00:05:27,601 --> 00:05:29,470 IT'S FOUND ON THE OUTSIDE OF THE 141 00:05:29,470 --> 00:05:29,670 VIRUS. 142 00:05:29,670 --> 00:05:33,340 IT'S WHAT INTERACTS WITH THE 143 00:05:33,340 --> 00:05:36,443 IMMUNE SYSTEM AND THE HOST, 144 00:05:36,443 --> 00:05:37,211 FIRST. 145 00:05:37,211 --> 00:05:40,514 SO IT'S THE TARGET OF LOTS OF 146 00:05:40,514 --> 00:05:41,248 ANTI-VIRAL STRATEGIES. 147 00:05:41,248 --> 00:05:42,816 THE IDEA THEN IF YOU DON'T HAVE 148 00:05:42,816 --> 00:05:44,785 A VIRUS YOU CAN RECONSTRUCT THIS 149 00:05:44,785 --> 00:05:47,187 WHOLE GENOME OR AT LEAST PART OF 150 00:05:47,187 --> 00:05:49,256 IT THROUGH REVERSE GENETICS IF 151 00:05:49,256 --> 00:05:52,993 YOU WANT TO STUDY 152 00:05:52,993 --> 00:05:57,598 UNCHARACTERIZED VIRUS. 153 00:05:57,598 --> 00:05:59,500 NUCLEOTIDE SYNTHESIS IS ROUTINE, 154 00:05:59,500 --> 00:06:01,402 USED FOR PRIMERS, 20 TO 60 BASE 155 00:06:01,402 --> 00:06:02,636 PAIRS IS A FEW DOLLARS. 156 00:06:02,636 --> 00:06:04,705 AS YOU GO UP IN SIZE YOU GET AN 157 00:06:04,705 --> 00:06:05,806 INCREASE IN COST. 158 00:06:05,806 --> 00:06:07,641 AND THE CORONAVIRUS GENOME IS 159 00:06:07,641 --> 00:06:07,975 NOT EASY. 160 00:06:07,975 --> 00:06:10,477 IT'S 30,000 BASE PAIRS. 161 00:06:10,477 --> 00:06:14,882 SO THIS CAN COST $15,000 OR 162 00:06:14,882 --> 00:06:18,252 MORE, MONTHS TO HAVE 163 00:06:18,252 --> 00:06:20,354 SYNTHESIZED, LONGER TO ASSEMBLE. 164 00:06:20,354 --> 00:06:22,222 SOMETIMES WE CAN SHORTEN THIS 165 00:06:22,222 --> 00:06:25,359 DOWN TO THE SPIKE GENE, THE 166 00:06:25,359 --> 00:06:26,694 OUTER MOST PROTEIN TO SEE WHAT 167 00:06:26,694 --> 00:06:27,561 IT CAN DO. 168 00:06:27,561 --> 00:06:31,765 AT A FEW THOUSAND BASE PAIRS CAN 169 00:06:31,765 --> 00:06:33,367 COST MORE THAN A THOUSAND 170 00:06:33,367 --> 00:06:33,934 DOLLARS TO HAVE SYNTHESIZED. 171 00:06:33,934 --> 00:06:36,904 IF YOU WANT TO STUDY HUNDREDS OR 172 00:06:36,904 --> 00:06:38,172 THOUSANDS OF VIRUSES IN 173 00:06:38,172 --> 00:06:39,373 PARALLEL, YOU KNOW, YOU NEED 174 00:06:39,373 --> 00:06:41,041 SOME OTHER WAY TO GET AT THIS 175 00:06:41,041 --> 00:06:44,111 QUESTION BECAUSE THIS KIND OF 176 00:06:44,111 --> 00:06:46,146 APPROACH WOULD BE -- IT'S NOT 177 00:06:46,146 --> 00:06:46,413 FEASIBLE. 178 00:06:46,413 --> 00:06:48,349 SO MY WORK COMES DOWN TO HOW CAN 179 00:06:48,349 --> 00:06:49,817 WE STUDY MORE OF THESE VIRUSES 180 00:06:49,817 --> 00:06:50,784 FOR LESS? 181 00:06:50,784 --> 00:06:52,853 WHAT IS THE SMALLEST REGION OF 182 00:06:52,853 --> 00:06:54,488 THE GENOME WE COULD SYNTHESIZE 183 00:06:54,488 --> 00:06:56,457 AND ACTUALLY TEST IN SOME SORT 184 00:06:56,457 --> 00:06:59,526 OF LABORATORY ASSAY TO LEARN 185 00:06:59,526 --> 00:07:01,061 ABOUT A VIRUS'S ABILITY TO 186 00:07:01,061 --> 00:07:05,332 INFECT MUSEUM -- HUMAN CELLS. 187 00:07:05,332 --> 00:07:12,773 THE 2020 STUDY WAS ON THE 188 00:07:12,773 --> 00:07:14,641 SARBICO VIRUSES. 189 00:07:14,641 --> 00:07:15,843 WE HAD SOME STRUCTURAL 190 00:07:15,843 --> 00:07:17,177 MECHANISTIC DATA FROM 2018, AND 191 00:07:17,177 --> 00:07:19,780 THERE WERE SEVERAL LIVE VIRUSES 192 00:07:19,780 --> 00:07:20,047 STUDIED. 193 00:07:20,047 --> 00:07:22,082 ANYTHING WE WERE ABLE TO SHOW IN 194 00:07:22,082 --> 00:07:23,617 THIS ASSAY WE'VE BEEN DEVELOPING 195 00:07:23,617 --> 00:07:27,121 WE COULD THEN VERIFY WITH THE 196 00:07:27,121 --> 00:07:29,089 PREVIOUSLY PUBLISHED LITERATURE. 197 00:07:29,089 --> 00:07:37,331 SO, THE CORONAVIRUSES ARE BROKEN 198 00:07:37,331 --> 00:07:39,833 DOWN INTO FOUR GENERA. 199 00:07:39,833 --> 00:07:41,268 IT'S THE BETA CORONAVIRUSES THAT 200 00:07:41,268 --> 00:07:44,438 HAVE PATTERNS OF ZOONOSIS AND 201 00:07:44,438 --> 00:07:51,011 SEVERE HUMAN DISEASE, SO I'M 202 00:07:51,011 --> 00:07:58,886 SHOWING DIFFERENT SUBJENERA 203 00:07:58,886 --> 00:08:09,430 SARBE INCLUDES SARS, AND WE HAVE 204 00:08:10,097 --> 00:08:12,232 EMBICOVIRUSES, BUT NOBICOVIRUS 205 00:08:12,232 --> 00:08:14,368 IS FAIRLY BAT SPECIFIC. 206 00:08:14,368 --> 00:08:17,271 HALF MIGHT HAVE POTENTIAL TO 207 00:08:17,271 --> 00:08:20,974 INFECT ACROSS SPECIES BARRIERS 208 00:08:20,974 --> 00:08:21,575 OR CAUSE DISEASE. 209 00:08:21,575 --> 00:08:24,211 IF WE LOOK AT ARRANGEMENT OF 210 00:08:24,211 --> 00:08:26,046 SPIKE GENE, THIS IS OUR SPIKE ON 211 00:08:26,046 --> 00:08:28,082 THE OUTSIDE, INTERACTS WITH THE 212 00:08:28,082 --> 00:08:34,988 RECEPTOR, THROUGH JUST A SMALL 213 00:08:34,988 --> 00:08:37,524 REGION OF RECEPTOR BINDING 214 00:08:37,524 --> 00:08:38,025 DOMAIN. 215 00:08:38,025 --> 00:08:40,928 YOU CAN APPRECIATE IT'S THIS ONE 216 00:08:40,928 --> 00:08:42,229 SINGLE CONTIGUOUS DOMAIN IN THE 217 00:08:42,229 --> 00:08:42,896 BETA CORONAVIRUS SPIKE. 218 00:08:42,896 --> 00:08:44,231 IF WE LOOK WHERE IT'S BEEN 219 00:08:44,231 --> 00:08:48,702 MAPPED FOR MANY OF THESE VIRUSES 220 00:08:48,702 --> 00:08:50,337 ACROSS THE DIFFERENT SUBGENERA 221 00:08:50,337 --> 00:08:52,172 WE CAN SEE IT'S BASICALLY IN THE 222 00:08:52,172 --> 00:08:54,108 SAME SPOT, ROUGHLY THE SAME 223 00:08:54,108 --> 00:08:56,143 ADVISE FOR A LOT OF THESE 224 00:08:56,143 --> 00:08:56,376 VIRUSES. 225 00:08:56,376 --> 00:09:06,920 IF WE LOOK WITHIN, JUST SARBICO 226 00:09:08,122 --> 00:09:11,558 IT'S MORE HOMOGENOUS, CAN WE 227 00:09:11,558 --> 00:09:13,227 JUST TEST DOMAINS FROM THESE? 228 00:09:13,227 --> 00:09:14,761 TO ILLUSTRATE THE APPROACH HERE, 229 00:09:14,761 --> 00:09:20,234 THIS IS A SPIKE TRIMER FOR 230 00:09:20,234 --> 00:09:22,736 SARS-COV-1 BOUND TO ITS RECEPTOR 231 00:09:22,736 --> 00:09:24,371 HUMANASE 2. 232 00:09:24,371 --> 00:09:29,943 WE 233 00:09:29,943 --> 00:09:30,944 HUMAN ACE-2. 234 00:09:30,944 --> 00:09:33,547 IT'S CAPABLE OF INDEPENDENTLY 235 00:09:33,547 --> 00:09:34,314 FOLDING. 236 00:09:34,314 --> 00:09:36,083 GROUPS CAN PURIFY THIS FRAGMENT 237 00:09:36,083 --> 00:09:42,856 AND DO CRYSTALLOGRAPHY STUDIES. 238 00:09:42,856 --> 00:09:45,058 WONDERING IF WE CAN EXCISE THE 239 00:09:45,058 --> 00:09:47,361 SPIKE OUT OF SARS 1 AND REPLACE 240 00:09:47,361 --> 00:09:48,795 WITH RECEPTOR BINDING DOMAIN 241 00:09:48,795 --> 00:09:49,930 FROM OTHER VIRUSES. 242 00:09:49,930 --> 00:09:55,169 AND SO THIS CHIMERIC SPIKE 243 00:09:55,169 --> 00:09:56,570 APPROACH WE TOOK, CODON 244 00:09:56,570 --> 00:09:59,206 OPTIMIZED SARS SPIKE FOR HUMAN 245 00:09:59,206 --> 00:10:01,642 CARS, APPENDED C-TERMINAL SLIDE 246 00:10:01,642 --> 00:10:02,976 TAG, INTRODUCED SILENT MUTATIONS 247 00:10:02,976 --> 00:10:04,511 THAT ARE JUST OUTSIDE OF THE 248 00:10:04,511 --> 00:10:05,179 RECEPTOR BINDING DOMAIN. 249 00:10:05,179 --> 00:10:06,980 THEY DON'T CHANGE THE CODING 250 00:10:06,980 --> 00:10:09,750 SEQUENCE BUT THEY ALLOW US TO AT 251 00:10:09,750 --> 00:10:11,618 THE DNA LEVEL REPLACE RECEPTOR 252 00:10:11,618 --> 00:10:12,452 BINDING DOMAIN FROM SARS 1 WITH 253 00:10:12,452 --> 00:10:18,058 THAT OF ANY OF THE OTHER 254 00:10:18,058 --> 00:10:20,360 SARBECOVIRUS OR LINEAGE B SPIKE 255 00:10:20,360 --> 00:10:21,662 RBDs. 256 00:10:21,662 --> 00:10:22,296 COMPARED TO PREVIOUS APPROACHES 257 00:10:22,296 --> 00:10:25,199 IN THE COST OF SEVERAL THOUSAND 258 00:10:25,199 --> 00:10:28,235 DOLLARS, FOR GENE TO TEST, WE 259 00:10:28,235 --> 00:10:29,803 COULD TEST RECEPTOR BINDING 260 00:10:29,803 --> 00:10:31,538 DOMAIN FOR UNDER $130, AND IT 261 00:10:31,538 --> 00:10:35,042 ONLY TOOK ABOUT SIX DICE HAVE 262 00:10:35,042 --> 00:10:38,979 THE SEQUENCE SYNTHESIZED, 263 00:10:38,979 --> 00:10:39,746 SOMETIMES LESS. 264 00:10:39,746 --> 00:10:43,884 SO FASTER MEANING WE COULD SCALE 265 00:10:43,884 --> 00:10:44,084 IT UP. 266 00:10:44,084 --> 00:10:47,854 ADJUST RECEPTOR BINDING DOMAIN 267 00:10:47,854 --> 00:10:51,225 FROM SARS 1, REPLACE WITH 268 00:10:51,225 --> 00:10:53,026 DIFFERENT SYNTHETIC RECEPTOR 269 00:10:53,026 --> 00:10:57,364 BINDING DOMAIN, MAKE SINGLE 270 00:10:57,364 --> 00:11:01,101 CELL -- SINGLE VEHICLEEL VSV 271 00:11:01,101 --> 00:11:04,171 PARTICLES CAN CHIMERIC SPIKES, 272 00:11:04,171 --> 00:11:07,307 ON THE OUTSIDE OF THE PARTICLE, 273 00:11:07,307 --> 00:11:10,377 INFECT TARGET SELLS, MEASURE 274 00:11:10,377 --> 00:11:11,378 LUCIFERASE PRODUCED FROM 275 00:11:11,378 --> 00:11:14,748 INFECTION AS READOUT FOR CELL 276 00:11:14,748 --> 00:11:16,049 ENTRY FROM RECEPTOR BINDING 277 00:11:16,049 --> 00:11:18,385 DOMAIN, IT TOOK ABOUT A YEAR OR 278 00:11:18,385 --> 00:11:20,120 SO OF DEVELOPMENT BECAUSE MAKING 279 00:11:20,120 --> 00:11:21,755 A CHIMERIC SPIKE THAT COULD WORK 280 00:11:21,755 --> 00:11:23,290 FOR ALL OF THE DIFFERENT VIRUSES 281 00:11:23,290 --> 00:11:26,526 TOOK A LITTLE BIT OF TRIAL AND 282 00:11:26,526 --> 00:11:26,727 ERROR. 283 00:11:26,727 --> 00:11:32,366 TO SUM SUMMARIZE THIS WAS PUBLD 284 00:11:32,366 --> 00:11:35,869 IN 2020, WE SCREENED 285 00:11:35,869 --> 00:11:36,970 BASICALLY -- DEVELOPED THIS 286 00:11:36,970 --> 00:11:37,838 CHIMERIC SPIKE APPROACH, 287 00:11:37,838 --> 00:11:41,475 SCREENED A LARGE PANEL OF 20 288 00:11:41,475 --> 00:11:43,877 VIRUSES, REPRESENTATIVE OF EVERY 289 00:11:43,877 --> 00:11:44,511 SINGLE NATURAL PUBLISHED VARIANT 290 00:11:44,511 --> 00:11:49,049 OF THE RECEPTOR BINDING DOMAIN 291 00:11:49,049 --> 00:11:51,451 FOR SARBECOVIRUSS AT THE TIME 292 00:11:51,451 --> 00:11:58,025 AND THESE DOMAINS COULD 293 00:11:58,025 --> 00:11:58,759 PHYLOGENETICICALLY CLUSTER AND 294 00:11:58,759 --> 00:12:03,363 CARRIED OVER TO CELL ENTRY 295 00:12:03,363 --> 00:12:05,465 POTENTIAL, RECEPTOR TROPISM, 296 00:12:05,465 --> 00:12:14,207 CLADE 1 SARBECOVIRUS USED HUMAN 297 00:12:14,207 --> 00:12:16,176 ACE-2, CLADE 2 DON'T USE ANY OF 298 00:12:16,176 --> 00:12:17,411 THE KNOWN CORONAVIRUS RECEPTORS 299 00:12:17,411 --> 00:12:20,080 ALTHOUGH A FEW DO HAVE ABILITY 300 00:12:20,080 --> 00:12:22,616 TO INFECT HUMAN CELLS. 301 00:12:22,616 --> 00:12:25,919 AND BECAUSE THIS APPROACH WAS SO 302 00:12:25,919 --> 00:12:27,854 QUICK AND CHEAP, WE WERE 303 00:12:27,854 --> 00:12:31,491 ACTUALLY ABLE TO PRODUCE THE 304 00:12:31,491 --> 00:12:32,059 FIRST LABORATORY DATA WITH 305 00:12:32,059 --> 00:12:34,795 SARS-COV-2 12 DAYS AFTER THE 306 00:12:34,795 --> 00:12:35,996 GENOME WAS RELEASED ONLINE, SO 307 00:12:35,996 --> 00:12:37,631 WE WERE ABLE TO SHOW IN JANUARY 308 00:12:37,631 --> 00:12:40,233 I THINK, END OF JANUARY, ACE-2 309 00:12:40,233 --> 00:12:44,504 WAS RECEPTOR FOR THIS VIRUS AND 310 00:12:44,504 --> 00:12:48,809 USED ITS HIGHER EFFICIENCY THAN 311 00:12:48,809 --> 00:12:58,952 SARS 1. 312 00:12:59,586 --> 00:13:01,822 SO WHEN STATERRED MY LAB THEN AT 313 00:13:01,822 --> 00:13:03,357 WSU WE HAD A LARGE PILE OF 314 00:13:03,357 --> 00:13:04,658 SEQUENCE DATA. 315 00:13:04,658 --> 00:13:07,527 I PARTNERED WITH SOME FOLKS IN 316 00:13:07,527 --> 00:13:11,898 OUR MATHEMATICS DEPARTMENT, WHO 317 00:13:11,898 --> 00:13:14,634 USED NETWORK ANALYSIS TO 318 00:13:14,634 --> 00:13:16,603 BASICALLY CHARACTERIZE AND 319 00:13:16,603 --> 00:13:17,804 ANALYZE GENETIC SEQUENCES AND 320 00:13:17,804 --> 00:13:20,207 WERE ABLE TO USE NETWORK 321 00:13:20,207 --> 00:13:21,742 ANALYSIS TO CLUSTER THE 322 00:13:21,742 --> 00:13:23,777 DIFFERENT VIRUSES BASED OFF OF 323 00:13:23,777 --> 00:13:24,144 ENTRY PHENOTYPE. 324 00:13:24,144 --> 00:13:26,246 AND SO THIS IS THE BEGINNING OF 325 00:13:26,246 --> 00:13:30,851 A MODEL WE CAN USE TO PREDICT 326 00:13:30,851 --> 00:13:32,552 WHERE NEW VIRUSES -- THEIR CELL 327 00:13:32,552 --> 00:13:33,787 ENTRY POTENTIAL. 328 00:13:33,787 --> 00:13:35,322 WHAT WAS IMPORTANT WE COULD 329 00:13:35,322 --> 00:13:37,858 ACTUALLY DIG INTO THE GROUP WE 330 00:13:37,858 --> 00:13:40,060 DIDN'T KNOW RECEPTOR FOR AND SAY 331 00:13:40,060 --> 00:13:45,399 BASED OFF THE ENTRY DATA COULD 332 00:13:45,399 --> 00:13:47,501 SAY WHICH OF THE NEWLY 333 00:13:47,501 --> 00:13:48,268 DISCOVERED SARBECOVIRUSS IN THIS 334 00:13:48,268 --> 00:13:50,570 CLADE WOULD BE ABLE TO INFECT 335 00:13:50,570 --> 00:13:53,206 HUMAN CELLS OR NOT. 336 00:13:53,206 --> 00:13:54,274 THAT'S THE POWER OF THIS 337 00:13:54,274 --> 00:13:56,476 APPROACH WE DON'T HAVE TO KNOW 338 00:13:56,476 --> 00:13:57,778 RECEPTOR FOR OUR MODELING 339 00:13:57,778 --> 00:13:59,012 APPROACHES TO BE ACCURATE 340 00:13:59,012 --> 00:14:03,917 BECAUSE WE'RE SCREENING SUCH A 341 00:14:03,917 --> 00:14:07,854 LARGE GROUP OF VIRUSES. 342 00:14:07,854 --> 00:14:12,225 I PARTNERED WITH THE INSTITUTE 343 00:14:12,225 --> 00:14:13,660 OF VIROLOGY, REFINED TECHNIQUES 344 00:14:13,660 --> 00:14:16,296 WE USED TO -- I GROW ACE-2 345 00:14:16,296 --> 00:14:17,697 INDEPENDENT SARBECOVIRUSS AND 346 00:14:17,697 --> 00:14:20,333 WERE ABLE TO SHOW REPLICATION OF 347 00:14:20,333 --> 00:14:22,636 MOLECULAR CLONE AND LAST YEAR 348 00:14:22,636 --> 00:14:25,138 WERE ACTUALLY ABLE TO USE WHAT 349 00:14:25,138 --> 00:14:35,615 WE LEARNED ABOUT ACE 1 OF 2 350 00:14:35,816 --> 00:14:36,750 INDEPENDENT VIRUSES, GOING TO 351 00:14:36,750 --> 00:14:37,918 ISOLATING ONE OF THOSE VIRUSES 352 00:14:37,918 --> 00:14:41,855 IN A HUMAN CELL LINE AS WE WERE 353 00:14:41,855 --> 00:14:42,522 KIND OF PREDICTING. 354 00:14:42,522 --> 00:14:49,095 WE ALSO CAN USE OUR TOOLS TO 355 00:14:49,095 --> 00:14:50,197 CONTINUALLY SURVEY SEQUENCE 356 00:14:50,197 --> 00:14:50,864 BASE, AS NEW VIRUSES ARE 357 00:14:50,864 --> 00:14:52,499 DISCOVERED WE CAN PLUG THEM INTO 358 00:14:52,499 --> 00:14:55,602 OUR SYSTEM AND GET A SNAPSHOT 359 00:14:55,602 --> 00:14:58,004 FOR THEIR ABILITY TO INFECT 360 00:14:58,004 --> 00:15:00,841 HUMAN CELLS AND HOW EFFECTIVE 361 00:15:00,841 --> 00:15:02,976 ARE VACCINES FOR SARS 2 FOR 362 00:15:02,976 --> 00:15:03,777 EXAMPLE AGAINST THESE OTHER 363 00:15:03,777 --> 00:15:05,345 VIRUSES, SO A FEW YEARS AGO WE 364 00:15:05,345 --> 00:15:09,616 FOUND A VIRUS THAT WAS 365 00:15:09,616 --> 00:15:11,785 DISCOVERED IN RUSSIAN, IN 2021, 366 00:15:11,785 --> 00:15:13,653 COULD USE HUMAN ACE-2, AND THEN 367 00:15:13,653 --> 00:15:16,289 WE SHOWED THAT ACTUALLY A 368 00:15:16,289 --> 00:15:17,924 CHIMERIC SPIKE BETWEEN SARS 2 369 00:15:17,924 --> 00:15:19,926 WITH JUST RECEPTOR BINDING 370 00:15:19,926 --> 00:15:22,195 DOMAIN FROM THIS RUSSIAN SPIKE 371 00:15:22,195 --> 00:15:24,531 WAS ABLE TO RESIST BASICALLY 372 00:15:24,531 --> 00:15:25,298 SERUM FROM VACCINATED 373 00:15:25,298 --> 00:15:28,668 INDIVIDUALS AND PEOPLE WHO HAD 374 00:15:28,668 --> 00:15:30,203 BEEN INFECTED WITH OMICRON. 375 00:15:30,203 --> 00:15:31,037 SO SUGGESTING REALLY THAT 376 00:15:31,037 --> 00:15:33,473 THERE'S NOT A LOT OF 377 00:15:33,473 --> 00:15:34,808 CROSS-PROTECTION BETWEEN EVEN 378 00:15:34,808 --> 00:15:37,210 RESPONSES TO NATURAL INFECTION 379 00:15:37,210 --> 00:15:39,246 FOR SOME OF THESE OTHER 380 00:15:39,246 --> 00:15:43,783 SARBECOVIRUSS LOOMING ON THE 381 00:15:43,783 --> 00:15:47,821 HORIZON WITH HUMAN ACE-2 TROPISM 382 00:15:47,821 --> 00:15:50,223 WITH SIMILAR EFFICIENCY TO SARS 383 00:15:50,223 --> 00:15:50,357 2. 384 00:15:50,357 --> 00:15:53,760 FINALLY WE JUST -- SO JUST 385 00:15:53,760 --> 00:15:54,728 COLLECTING INFORMATION ISN'T 386 00:15:54,728 --> 00:15:55,695 SUFFICIENT. 387 00:15:55,695 --> 00:15:58,098 WE'RE EAGER TO TRY TO EXPAND ON 388 00:15:58,098 --> 00:15:59,766 THESE RESULTS AND DEVELOP THEM 389 00:15:59,766 --> 00:16:02,936 FURTHER INTO, YOU KNOW, AN 390 00:16:02,936 --> 00:16:04,237 ACTUAL INTERVENTION TO BLOCK 391 00:16:04,237 --> 00:16:05,872 TRANSMISSION OF SOME OF THESE 392 00:16:05,872 --> 00:16:06,373 VIRUSES. 393 00:16:06,373 --> 00:16:09,376 SO, WHAT WE WERE ABLE TO SHOW 394 00:16:09,376 --> 00:16:11,678 LAST YEAR IN COLLABORATION WITH 395 00:16:11,678 --> 00:16:14,314 A GROUP WITH WENDY'S GROUP AT 396 00:16:14,314 --> 00:16:16,716 HARWARD IN THE PHARMACOLOGY 397 00:16:16,716 --> 00:16:19,119 DEPARTMENT, THEY HAVE BEEN 398 00:16:19,119 --> 00:16:21,922 DEVELOPING AN ACE-2 BASICALLY 399 00:16:21,922 --> 00:16:23,490 VIRUS INHIBITORY DRUG, AND WE 400 00:16:23,490 --> 00:16:25,892 WERE ABLE TO HELP THEM TEST AND 401 00:16:25,892 --> 00:16:28,495 VALIDATE THEIR REAGENTS ACROSS A 402 00:16:28,495 --> 00:16:33,133 WIDER SPECTRUM OF THE 403 00:16:33,133 --> 00:16:33,800 SARBECOVIRUSES SHOWING THEIR 404 00:16:33,800 --> 00:16:36,636 MOLECULE WAS ABLE TO INHIBIT 405 00:16:36,636 --> 00:16:38,939 INFECTION BY A NUMBER OF THE 406 00:16:38,939 --> 00:16:39,606 SARBECOVIRUSES, INCLUDING THE 407 00:16:39,606 --> 00:16:42,876 RUSSIAN VIRUS WE HAD JUST FOUND 408 00:16:42,876 --> 00:16:44,611 WITH ACE-2 USED THE YEAR BEFORE 409 00:16:44,611 --> 00:16:46,513 THIS STUDY. 410 00:16:46,513 --> 00:16:49,015 SO REALLY WE WENT FROM 2021 TO A 411 00:16:49,015 --> 00:16:52,519 SEQUENCE ON A DATABASE TO HAVING 412 00:16:52,519 --> 00:16:53,954 ANTI-VIRAL THERAPEUTIC DRUG WITH 413 00:16:53,954 --> 00:17:00,293 EFFICACY IN SMALL ANIMAL MODEL 414 00:17:00,293 --> 00:17:02,796 BY 2023 AND HAVING THE DATA 415 00:17:02,796 --> 00:17:04,130 SHOWING EFFICACY AGAINST THAT 416 00:17:04,130 --> 00:17:04,898 VIRUS IN PARTICULAR. 417 00:17:04,898 --> 00:17:06,299 I THINK THAT'S THE BIGGER GOAL 418 00:17:06,299 --> 00:17:10,236 FOR OUR WORK TO SCREEN THE 419 00:17:10,236 --> 00:17:11,338 VIRUSES, IDENTIFY THREATS, AND 420 00:17:11,338 --> 00:17:14,507 WORK AND PARTNER WITH LABS 421 00:17:14,507 --> 00:17:15,375 DEVELOPING THERAPEUTICS. 422 00:17:15,375 --> 00:17:17,911 CURRENTLY, WE'RE WORKING ON SOME 423 00:17:17,911 --> 00:17:20,280 STUDIES TO IDENTIFY THE ENTRY 424 00:17:20,280 --> 00:17:23,583 ROUTE AND RECEPTORS USED BY 425 00:17:23,583 --> 00:17:25,151 THOSE ACE-2 INDEPENDENT VIRUSES. 426 00:17:25,151 --> 00:17:26,653 MY LAB IS FUNCTIONAL VIROMICS. 427 00:17:26,653 --> 00:17:27,854 WHAT DO I MEAN BY THAT? 428 00:17:27,854 --> 00:17:30,490 IT'S REALLY THIS KIND OF 429 00:17:30,490 --> 00:17:32,659 AGGREGATION OF DIFFERENT 430 00:17:32,659 --> 00:17:34,427 DISCIPLINES WHERE WE CAN FIRST 431 00:17:34,427 --> 00:17:36,830 SCREEN THE VIROME FOR DIFFERENT 432 00:17:36,830 --> 00:17:38,465 PHENOTYPES, CURRENTLY LOOKING AT 433 00:17:38,465 --> 00:17:39,899 VIRAL ENTRY AND VACCINE 434 00:17:39,899 --> 00:17:40,767 RESISTANCE, TOOLS ARE DESIGNED 435 00:17:40,767 --> 00:17:43,937 TO LET US LOOK AT PROTEASE USAGE 436 00:17:43,937 --> 00:17:45,372 AND OTHER POST-ENTRY PHENOTYPES 437 00:17:45,372 --> 00:17:46,806 AS WELL. 438 00:17:46,806 --> 00:17:50,744 WE CAN THEN PERFORM BULK SCREENS 439 00:17:50,744 --> 00:17:52,512 ON THESE CHIMERIC GENES, AND TRY 440 00:17:52,512 --> 00:17:55,148 TO LEARN AS MUCH AS WE CAN ABOUT 441 00:17:55,148 --> 00:17:56,249 THE GROUP THAT WE'RE AFTER. 442 00:17:56,249 --> 00:17:58,652 AND WE CAN USE THOSE TOOLS THEN 443 00:17:58,652 --> 00:18:01,688 TO CONTINUE SURVEILLANCE ON THAT 444 00:18:01,688 --> 00:18:04,124 GROUP, AND REFINE OUR 445 00:18:04,124 --> 00:18:05,158 PROTOTYPES, MAKE BETTER CHIMERIC 446 00:18:05,158 --> 00:18:07,627 PROTEINS THAT LET US GET AT 447 00:18:07,627 --> 00:18:08,294 DIFFERENT PHENOTYPES AND 448 00:18:08,294 --> 00:18:09,462 CONTINUE THAT SCREENING AND 449 00:18:09,462 --> 00:18:10,196 SURVEILLANCE. 450 00:18:10,196 --> 00:18:11,564 BUT ONCE WE ALSO HAVE THIS -- 451 00:18:11,564 --> 00:18:13,867 ONCE WE HAVE THIS DATA THOUGH 452 00:18:13,867 --> 00:18:16,169 FROM OUR INITIAL SCREENING, WE 453 00:18:16,169 --> 00:18:17,937 CAN TRY TO EXTRAPOLATE TRENDS 454 00:18:17,937 --> 00:18:21,307 ACROSS DIFFERENT TYPES OF 455 00:18:21,307 --> 00:18:22,742 VIRUSES, IDENTIFY DIFFERENT 456 00:18:22,742 --> 00:18:25,045 PHENOTYPES, FOR EXAMPLE, ACE-2 457 00:18:25,045 --> 00:18:27,447 INDEPENDENT ENTRY OR RESISTANCE 458 00:18:27,447 --> 00:18:30,817 TO SARS-COV-2 VACCINE SERUM. 459 00:18:30,817 --> 00:18:32,686 WE CAN LOOK FOR MOLECULAR 460 00:18:32,686 --> 00:18:33,453 DETERMINANTS, REITERATE ON THAT 461 00:18:33,453 --> 00:18:36,389 PROCESS OF SEEING HOW FAR 462 00:18:36,389 --> 00:18:37,157 PHENOTYPES ARE CONSERVED ACROSS 463 00:18:37,157 --> 00:18:40,560 A LARGE GROUP OF VIRUSES. 464 00:18:40,560 --> 00:18:41,861 ONCE WE ACTUALLY HAVE OUR 465 00:18:41,861 --> 00:18:46,399 SCREENING DATA AND HAVE OUR 466 00:18:46,399 --> 00:18:49,436 CHARACTERIZATION DATA, WE CAN 467 00:18:49,436 --> 00:18:51,438 FEED THIS INTO COMPUTATIONAL 468 00:18:51,438 --> 00:18:54,274 MODELS, IDENTIFYING TRENDS, 469 00:18:54,274 --> 00:18:55,041 VALIDATING TRENDS WITH 470 00:18:55,041 --> 00:19:01,715 COMPUTATIONAL MODELS AND REFINE 471 00:19:01,715 --> 00:19:04,017 MODELS, USING WET LAB AND 472 00:19:04,017 --> 00:19:05,385 COMPUTATIONAL LABS TO 473 00:19:05,385 --> 00:19:06,119 CHARACTERIZE UNDERSTUDIED 474 00:19:06,119 --> 00:19:10,256 VIRUSES AT LARGER SCALE THAN WE 475 00:19:10,256 --> 00:19:12,325 KNOW WE CAN. 476 00:19:12,325 --> 00:19:14,394 WITH THAT INTRODUCTION 477 00:19:14,394 --> 00:19:18,665 TODAY'S -- THE BULK IS WITH THE 478 00:19:18,665 --> 00:19:19,566 MERBECOVIRUSES, WHAT WE'VE BEEN 479 00:19:19,566 --> 00:19:22,302 WORKING ON FOR THE PAST SIX OR 480 00:19:22,302 --> 00:19:27,207 SEVEN YEARS, CAN WE ASK THIS 481 00:19:27,207 --> 00:19:30,176 QUESTION FOR MERBECOVIRUSES? 482 00:19:30,176 --> 00:19:32,679 THE CHARACTERISTIC VIRUS IS 483 00:19:32,679 --> 00:19:34,981 MIDDLE EAST RESPIRATORY SYNDROME 484 00:19:34,981 --> 00:19:37,584 CORONAVIRUS DISCOVERED IN HUMANS 485 00:19:37,584 --> 00:19:39,352 IN 2012. 486 00:19:39,352 --> 00:19:40,653 AND IT'S CURRENTLY ENDEMIC 487 00:19:40,653 --> 00:19:44,190 BASICALLY IN THE MIDDLE EAST, 488 00:19:44,190 --> 00:19:47,360 TRANSMITS FROM DROMEDARY CAMELS 489 00:19:47,360 --> 00:19:50,630 REPEATEDLY. 490 00:19:50,630 --> 00:19:51,164 THANKFULLY THERE'S LOW 491 00:19:51,164 --> 00:19:53,700 HUMAN-TO-HUMAN TRANSMISSION BUT 492 00:19:53,700 --> 00:19:55,802 IT HAS A HIGH MORTALITY OF 36% 493 00:19:55,802 --> 00:19:58,204 IN REPORTED CASES. 494 00:19:58,204 --> 00:19:59,973 SO, IT IS CONCERNING BUT 495 00:19:59,973 --> 00:20:02,609 THANKFULLY FOR NOW IT'S NOT 496 00:20:02,609 --> 00:20:02,876 SPREADING. 497 00:20:02,876 --> 00:20:05,612 AND KIND OF SIMILAR TO WHAT WE 498 00:20:05,612 --> 00:20:08,148 SAW WITH SARS 1 AND SARS 2 IS 499 00:20:08,148 --> 00:20:09,682 REALLY AFTER THIS VIRUS WAS 500 00:20:09,682 --> 00:20:12,218 DISCOVERED THE MORE WE LOOK IN 501 00:20:12,218 --> 00:20:14,754 NATURE AND PERFORM VIRAL 502 00:20:14,754 --> 00:20:17,690 SURVEILLANCE STUDIES WE FIND 503 00:20:17,690 --> 00:20:18,792 MORE CORONAVIRUSES. 504 00:20:18,792 --> 00:20:24,364 SO HKU 4 AND HKU 5 WERE THE 505 00:20:24,364 --> 00:20:26,332 FIRST BAT MERBECOVIRUSES 506 00:20:26,332 --> 00:20:29,135 DISCOVERED, ACTUALLY DISCOVERED 507 00:20:29,135 --> 00:20:30,470 IN 2006 YEARS BEFORE MERS CAME 508 00:20:30,470 --> 00:20:31,905 OUT, BECAUSE WE DIDN'T HAVE 509 00:20:31,905 --> 00:20:34,741 TOOLS TO STUDY THESE VIRUSES, 510 00:20:34,741 --> 00:20:37,243 YOU KNOW, THERE WAS JUST 511 00:20:37,243 --> 00:20:37,577 SEQUENCE DATA. 512 00:20:37,577 --> 00:20:39,579 AND REALLY SINCE MERS EMERGED IN 513 00:20:39,579 --> 00:20:42,515 2012 WE FOUND THOUSANDS OF 514 00:20:42,515 --> 00:20:48,221 RELATED VIRUSES ACROSS BATS, 515 00:20:48,221 --> 00:20:50,056 HEDGEHOGS, PANGOLINS, IN ASIA, 516 00:20:50,056 --> 00:20:54,794 AFRICA, EUROPE AND MIDDLE EAST, 517 00:20:54,794 --> 00:20:58,631 A MORE DISTRIBUTION AND MORE 518 00:20:58,631 --> 00:21:00,133 DIVERSE. 519 00:21:00,133 --> 00:21:01,901 SINCE 2012 ONLY SIX STUDIED IN 520 00:21:01,901 --> 00:21:05,405 THE LAB, WITH HIGH DIVERSE IT'S 521 00:21:05,405 --> 00:21:11,311 MAKES MOST RELATIVES UNKNOWN. 522 00:21:11,311 --> 00:21:13,046 ZOO NOTING RISK UNDERSTANDING IS 523 00:21:13,046 --> 00:21:13,913 LOW. 524 00:21:13,913 --> 00:21:17,016 TO HOW WE TACKLED THIS APPROACH, 525 00:21:17,016 --> 00:21:18,318 THIS QUESTION, WE BASICALLY 526 00:21:18,318 --> 00:21:23,022 STARTED WITH VERY SIMILAR DESIGN 527 00:21:23,022 --> 00:21:25,859 TO THE SARS APPROACH, THE 528 00:21:25,859 --> 00:21:27,427 SARBECOVIRUS APPROACH, NOW 529 00:21:27,427 --> 00:21:31,464 WORKING WITH THE MERS SPIKE 530 00:21:31,464 --> 00:21:32,565 PROTEIN, SILENT RESTRICTION 531 00:21:32,565 --> 00:21:34,000 SITES, FLAG-tag ON IT TO 532 00:21:34,000 --> 00:21:36,536 REPLACE RECEPTOR BINDING DO HE 533 00:21:36,536 --> 00:21:44,744 MAIN, USE CHIMERIC SPIKES TO 534 00:21:44,744 --> 00:21:45,578 RECOVER PSEUDOTYPES, LUCIFERASE 535 00:21:45,578 --> 00:21:46,145 PSEUDOTYPES. 536 00:21:46,145 --> 00:21:53,486 I STARTED THIS WORK IN 2018, BUT 537 00:21:53,486 --> 00:21:55,889 SARBECOVIRUSES WERE EASIER AND 538 00:21:55,889 --> 00:21:56,623 IT MOVED FASTER. 539 00:21:56,623 --> 00:21:59,092 THEY ARE FOUND IN VERY FEW 540 00:21:59,092 --> 00:22:01,361 SPECIES, AND SO THEY ARE QUITE 541 00:22:01,361 --> 00:22:04,063 SIMILAR TO EACH OTHER. 542 00:22:04,063 --> 00:22:07,567 SOMETIMES 99% AT THE NUCLEOTIDE 543 00:22:07,567 --> 00:22:10,637 LEVEL, FOUND IN A LIMITED 544 00:22:10,637 --> 00:22:11,170 GEOGRAPHIC REGION ALTHOUGH 545 00:22:11,170 --> 00:22:17,944 THAT'S EXPANDING A LITTLE BIT. 546 00:22:17,944 --> 00:22:18,845 BUT THE MERBECOVIRUSES ARE FOUND 547 00:22:18,845 --> 00:22:21,247 IN A WIDE RANGE AND GEOGRAPHIC 548 00:22:21,247 --> 00:22:22,982 DISTRIBUTION, QUITE DIFFERENT 549 00:22:22,982 --> 00:22:26,486 FROM EACH OTHER, SOMETIMES ONLY 550 00:22:26,486 --> 00:22:27,587 65% SIMILAR AT NUCLEOTIDE LEVEL 551 00:22:27,587 --> 00:22:29,555 AT LEAST IN THE SPIKE GENE, 552 00:22:29,555 --> 00:22:31,090 CONFOUNDS THE EFFORT WHEN YOU'RE 553 00:22:31,090 --> 00:22:32,725 TRYING TO CALL WHERE EXACTLY TO 554 00:22:32,725 --> 00:22:35,028 MAKE A CHIMERIC PROTEIN YOU NEED 555 00:22:35,028 --> 00:22:36,229 TO KNOW EXACTLY AT THE AMINO 556 00:22:36,229 --> 00:22:39,732 ACID LEVEL WHERE YOU CAN MAKE 557 00:22:39,732 --> 00:22:41,935 THESE INTRODUCTIONS AND WHERE 558 00:22:41,935 --> 00:22:42,835 THEY DON'T WORK. 559 00:22:42,835 --> 00:22:48,708 AND SO WHAT I'M SHOWING IS 560 00:22:48,708 --> 00:22:49,709 ALIGNMENT OF THREE 561 00:22:49,709 --> 00:22:50,743 MERBECOVIRUSES, THERE'S KNOW ANY 562 00:22:50,743 --> 00:22:52,779 STRETCH OF AMINO ACID WIDELY 563 00:22:52,779 --> 00:22:57,417 CONSERVED ACROSS ALL OF THE 564 00:22:57,417 --> 00:22:58,885 DIFFERENT VIRUSES. 565 00:22:58,885 --> 00:23:00,653 AND SO FOR MANY YEARS EVERY TIME 566 00:23:00,653 --> 00:23:04,223 WE MAKE A CHIMERIC SPIKE IT WAS 567 00:23:04,223 --> 00:23:05,024 NON-FUNCTIONAL BASICALLY. 568 00:23:05,024 --> 00:23:06,459 AND SO, YOU KNOW, THIS IS 569 00:23:06,459 --> 00:23:08,294 BASICALLY A TRIAL AND ERROR 570 00:23:08,294 --> 00:23:10,596 PROCESS TO FIGURE OUT WHAT AMINO 571 00:23:10,596 --> 00:23:13,132 ACIDS WE CAN USE TO SAY THIS IS 572 00:23:13,132 --> 00:23:14,100 WHERE WE CAN INTRODUCE THE AMINO 573 00:23:14,100 --> 00:23:16,970 ACID SEQUENCE FROM ANOTHER 574 00:23:16,970 --> 00:23:17,170 VIRUS. 575 00:23:17,170 --> 00:23:19,372 SO WHILE THEY DON'T HAVE A LOT 576 00:23:19,372 --> 00:23:26,112 OF CONSERVED MOTIFS THEY DO HAVE 577 00:23:26,112 --> 00:23:27,246 CONSERVED GLYCINES IN YELLOW, 578 00:23:27,246 --> 00:23:34,587 SHOWN IN YELLOW, FOUND IN EVERY 579 00:23:34,587 --> 00:23:35,355 MERBECO VIRUS. 580 00:23:35,355 --> 00:23:36,689 IT TOOK MANY YEARS BUT THAT'S 581 00:23:36,689 --> 00:23:39,625 ALL WE COULD USE TO DEFINE THE 582 00:23:39,625 --> 00:23:42,562 EDGE OF THE RECEPTOR BINDING 583 00:23:42,562 --> 00:23:43,062 DOMAIN. 584 00:23:43,062 --> 00:23:44,230 GLYCINES ARE AT THE BASE OF THE 585 00:23:44,230 --> 00:23:44,430 SPIKE. 586 00:23:44,430 --> 00:23:47,233 I MEAN BASE OF THE RECEPTOR 587 00:23:47,233 --> 00:23:47,767 BINDING DOMAIN. 588 00:23:47,767 --> 00:23:49,569 AND SO WE THOUGHT MAYBE THIS IS 589 00:23:49,569 --> 00:23:57,343 A GOOD PLACE TO INTRODUCE BREAKS 590 00:23:57,343 --> 00:23:58,444 FOR CHANGING THE RBD. 591 00:23:58,444 --> 00:23:59,779 THEN THE QUESTION IS WHAT 592 00:23:59,779 --> 00:24:00,747 VIRUSES DO WE USE? 593 00:24:00,747 --> 00:24:02,181 WE'RE NOT GOING TO START MAKING 594 00:24:02,181 --> 00:24:03,950 A LARGE CHIMERIC PANEL. 595 00:24:03,950 --> 00:24:05,685 WE WANT GOOD CONTROLS THAT WOULD 596 00:24:05,685 --> 00:24:08,187 GIVE CONFIDENCE THAT WE CAN 597 00:24:08,187 --> 00:24:09,222 MEASURE DIFFERENT PHENOTYPES. 598 00:24:09,222 --> 00:24:10,490 AND SO RIGHT AS WE WERE 599 00:24:10,490 --> 00:24:12,792 FINISHING UP THE DESIGN OF OUR 600 00:24:12,792 --> 00:24:16,062 CHIMERIC SPIKE, THIS STUDY CAME 601 00:24:16,062 --> 00:24:19,232 OUT FROM CHINA SHOWING THAT 602 00:24:19,232 --> 00:24:21,334 MANY -- AT LEAST SOME 603 00:24:21,334 --> 00:24:22,201 MERBECOVIRUSES FOUND IN AFRICAN 604 00:24:22,201 --> 00:24:25,171 BATS WERE CAPABLE OF USING HUMAN 605 00:24:25,171 --> 00:24:26,939 ACE-2, WHICH AT THE TIME WAS 606 00:24:26,939 --> 00:24:29,242 QUITE A PARADIGM SHIFT BECAUSE 607 00:24:29,242 --> 00:24:31,210 WE THOUGHT THESE VIRUSES -- WE 608 00:24:31,210 --> 00:24:34,480 KNEW OF ONLY MERS AND SOME OTHER 609 00:24:34,480 --> 00:24:35,715 BAT CORONAVIRUSES THAT USED 610 00:24:35,715 --> 00:24:39,318 DPP4, THE THOUGHT WAS ALL THE 611 00:24:39,318 --> 00:24:39,986 MERBECOVIRUSES PROBABLY USED 612 00:24:39,986 --> 00:24:41,621 DPP4 OR SOMETHING LIKE IT. 613 00:24:41,621 --> 00:24:44,457 BUT THAT HASN'T HELD UP TO BE 614 00:24:44,457 --> 00:24:44,657 TRUE. 615 00:24:44,657 --> 00:24:46,292 AND THIS GROUP SHOWED ACTUALLY 616 00:24:46,292 --> 00:24:49,162 SOME OTHER VIRUSES CAN USE ACE-2 617 00:24:49,162 --> 00:24:51,364 SO COMPLETELY DIFFERENT RECEPTOR 618 00:24:51,364 --> 00:24:53,866 USE ACROSS VIRUSES BOTH 619 00:24:53,866 --> 00:24:54,867 TECHNICALLY MERBECOVIRUSES. 620 00:24:54,867 --> 00:24:57,470 THIS BECAME A GREAT TARGET FOR 621 00:24:57,470 --> 00:24:59,872 US, WITH THE IDEA OF CAN WE 622 00:24:59,872 --> 00:25:01,441 REPLACE THE RECEPTOR BINDING 623 00:25:01,441 --> 00:25:05,578 DOMAIN OF MERS WITH ONE OF THESE 624 00:25:05,578 --> 00:25:08,081 ACE-2-USING VIRUSES IN ORDER TO, 625 00:25:08,081 --> 00:25:11,717 YOU KNOW, EXCHANGE THE RECEPTOR 626 00:25:11,717 --> 00:25:11,951 TROPISM. 627 00:25:11,951 --> 00:25:14,353 AND SO I'M SHOWING A SMALL PANEL 628 00:25:14,353 --> 00:25:15,455 OF CHIMERIC SPIKES I MADE. 629 00:25:15,455 --> 00:25:19,358 AND WE HAVE THE MERS ORIGINAL 630 00:25:19,358 --> 00:25:20,193 SPIKE. 631 00:25:20,193 --> 00:25:22,128 WE HAVE THE HKU4 SPIKE, BAT 632 00:25:22,128 --> 00:25:23,663 CORONAVIRUS, CLOSELY RELATED TO 633 00:25:23,663 --> 00:25:25,965 MERS, THEY BOTH USE DPP4. 634 00:25:25,965 --> 00:25:30,870 AND SO I MADE A CHIMERIC HKU4 635 00:25:30,870 --> 00:25:36,809 SPIKE WITH RECEPTOR BINDING 636 00:25:36,809 --> 00:25:38,444 DOMAIN HKU4 AND MERS, NOT EXPECT 637 00:25:38,444 --> 00:25:44,117 BE THAT TO CHANGE THE TROPISM, A 638 00:25:44,117 --> 00:25:46,519 SIMILAR WITH PDF 2180 SHOWN TO 639 00:25:46,519 --> 00:25:48,054 USE HUMAN ACE-2. 640 00:25:48,054 --> 00:25:50,022 AND BECAUSE I'M ALWAYS IN THE 641 00:25:50,022 --> 00:25:53,860 QUEST TO SEE IF I CAN LOWER COST 642 00:25:53,860 --> 00:25:56,496 OF STUDY, MOVE FASTER, I TRIED 643 00:25:56,496 --> 00:25:57,130 SLIGHTLY SMALLER VARIANTS JUST 644 00:25:57,130 --> 00:26:00,199 TO SEE IF WE COULD MINIMIZE THE 645 00:26:00,199 --> 00:26:03,236 AMOUNT OF SEQUENCE TO HAVE 646 00:26:03,236 --> 00:26:03,536 SYNTHESIZED. 647 00:26:03,536 --> 00:26:07,206 AND SO HERE'S A PANEL OF 648 00:26:07,206 --> 00:26:09,842 PSEUDOTYPES NOW, INFECTING THE 649 00:26:09,842 --> 00:26:11,544 HUMAN 293T CELL LINE WHICH 650 00:26:11,544 --> 00:26:14,547 DOESN'T SUPPRESS HIGH LEVELS OF 651 00:26:14,547 --> 00:26:17,283 CORONAVIRUS VIRUS RECEPTORS, NOT 652 00:26:17,283 --> 00:26:18,084 EXPECTING ENTRY CLEARLY. 653 00:26:18,084 --> 00:26:19,452 THAT'S WHAT WE SEE. 654 00:26:19,452 --> 00:26:20,887 THERE'S NO RELATIVE ENTRY. 655 00:26:20,887 --> 00:26:23,956 IF WE TRANSDUCE THESE CELLS WITH 656 00:26:23,956 --> 00:26:28,227 HUMAN DPP4 WE CAN SKI MERS AND 657 00:26:28,227 --> 00:26:29,762 HKU4, SPIKES CAN INFECT A LITTLE 658 00:26:29,762 --> 00:26:30,062 BIT. 659 00:26:30,062 --> 00:26:33,166 WHEN WE TRANSDUCE WITH HUMAN 660 00:26:33,166 --> 00:26:42,008 ACE-2, WE SEE THIS PDF 2180 661 00:26:42,008 --> 00:26:44,544 AFRICAN MERBECVIRUS CAN GET IN. 662 00:26:44,544 --> 00:26:45,978 THIS IS UNDER TEN-FOLD, NOT AS 663 00:26:45,978 --> 00:26:48,381 RELIABLE AS WE WOULD LIKE. 664 00:26:48,381 --> 00:26:51,984 SO ONE OF THE TRICKS IN OUR LAB 665 00:26:51,984 --> 00:26:56,122 TO LOOK AT ENTRY A LITTLE BIT 666 00:26:56,122 --> 00:26:56,689 MORE SPECIFICALLY IS INCLUDE 667 00:26:56,689 --> 00:26:58,724 TRYPSIN IN THE EXPERIMENT. 668 00:26:58,724 --> 00:27:02,161 TRYPSIN HELPS PROCESS THE SPIKE, 669 00:27:02,161 --> 00:27:05,131 POST-RECEPTOR ENGAGEMENT. 670 00:27:05,131 --> 00:27:10,036 NOT ALL CELL LINES EXPRESS 671 00:27:10,036 --> 00:27:11,037 EFFICIENTLY, EFFICIENTLY EXPRESS 672 00:27:11,037 --> 00:27:11,571 NECESSARY PROTEASE FOR 673 00:27:11,571 --> 00:27:13,005 CORONAVIRUS ENTRY. 674 00:27:13,005 --> 00:27:16,075 IF WE ADD TRYPSIN IT GREASES THE 675 00:27:16,075 --> 00:27:19,979 WHEELS OF INFECTION AND HELPS US 676 00:27:19,979 --> 00:27:20,546 DETECT LOW LEVEL INTERACTION 677 00:27:20,546 --> 00:27:24,784 BETWEEN IS HE RECEPTOR AND SPIKE 678 00:27:24,784 --> 00:27:26,686 GENE, DOESN'T CHANGE OUR STORY 679 00:27:26,686 --> 00:27:29,622 WITH OUR CHIMERIC SPIKE BUT 680 00:27:29,622 --> 00:27:34,493 SHOWS CLEAR STRONG ENTRY SIGNAL 681 00:27:34,493 --> 00:27:38,097 ACE-2 DEPENDENT BY CHANGING 682 00:27:38,097 --> 00:27:42,468 RECEPTOR DOMAIN, HIGHLY CONSERVE 683 00:27:42,468 --> 00:27:47,173 GLYCINE RESIDUES FLANK THE 684 00:27:47,173 --> 00:27:49,108 FUNCTIONAL VIRUS RBD. 685 00:27:49,108 --> 00:27:52,411 GENE BANK, 2,000 ENTRIES FOR 686 00:27:52,411 --> 00:27:54,280 MERS OR MERBECOVIRUSESS, MOST 687 00:27:54,280 --> 00:27:55,481 COME FROM DIFFERENT VIRUS 688 00:27:55,481 --> 00:27:56,816 DISCOVERY STUDIES WHERE THEY 689 00:27:56,816 --> 00:27:58,217 DIDN'T ALWAYS SEQUENCE THE WHOLE 690 00:27:58,217 --> 00:28:05,791 GENOME, SOMETIMES THEY ONLY 691 00:28:05,791 --> 00:28:07,426 SEQUENCED A FRAGMENT, 842 SPIKE 692 00:28:07,426 --> 00:28:08,494 GENES. 693 00:28:08,494 --> 00:28:12,265 IF WE REMOVE THE DIFFERENT -- 694 00:28:12,265 --> 00:28:14,200 BASICALLY MERS ISOLATES TAKEN 695 00:28:14,200 --> 00:28:15,801 OUT OF HUMAN PATIENTS OR MERS 696 00:28:15,801 --> 00:28:19,605 DIRECT 697 00:28:19,605 --> 00:28:20,906 DIRECTLY ISOLATEDs FROM CAMELS 698 00:28:20,906 --> 00:28:26,812 THAT GAVE HUMAN MERS WE'RE LEFT 699 00:28:26,812 --> 00:28:30,549 WITH 65 DIFFERENT SPIKES. 700 00:28:30,549 --> 00:28:32,418 ALL ARE UNIQUE, ONLY 34 UNIQUE 701 00:28:32,418 --> 00:28:33,853 VARIANTS OF THE RECEPTOR BINDING 702 00:28:33,853 --> 00:28:37,123 DOMAIN SO THIS DAUNTING QUESTION 703 00:28:37,123 --> 00:28:38,991 OF THOUSANDS OF ENTRIES REALLY 704 00:28:38,991 --> 00:28:41,594 CAN BE WHITTLED INTO A SMALL 705 00:28:41,594 --> 00:28:43,262 NUMBER THAT'S LARGELY 706 00:28:43,262 --> 00:28:44,130 REPRESENTATIVE OF ALL THE 707 00:28:44,130 --> 00:28:50,403 MERBECOVIRUSES WE HAVE THIS 708 00:28:50,403 --> 00:28:51,170 INFORMATION FOR. 709 00:28:51,170 --> 00:28:57,076 HERE IS A PANEL OF THE SPIKES, 710 00:28:57,076 --> 00:28:58,944 DIFFERENT BINDING DOMAINS. 711 00:28:58,944 --> 00:29:00,246 WE INCLUDED THE ORIGINAL. 712 00:29:00,246 --> 00:29:02,982 SHOWN HERE IS AN RBD AMINO ACID 713 00:29:02,982 --> 00:29:05,084 TREE, SO JUST LOOKING AT 714 00:29:05,084 --> 00:29:06,819 PHYLOGENETIC RELATIONSHIP WE CAN 715 00:29:06,819 --> 00:29:09,522 SEE THEY FORM -- SEEM TO FORM 716 00:29:09,522 --> 00:29:11,090 CLADES OR CLUSTERS, THIS IS MORE 717 00:29:11,090 --> 00:29:13,392 APPARENT WHEN WE LOOK AT AMINO 718 00:29:13,392 --> 00:29:15,361 ACID ARRANGEMENT OF THE RECEPTOR 719 00:29:15,361 --> 00:29:16,896 BINDING DOMAIN FROM 720 00:29:16,896 --> 00:29:19,332 THOUSAND-FOOT VIEW, THIS IS JUST 721 00:29:19,332 --> 00:29:20,933 N-TERMINUS TO C-TERMINUS, 722 00:29:20,933 --> 00:29:22,968 RECEPTOR BINDING DOMAIN, SHOWING 723 00:29:22,968 --> 00:29:25,871 PRESENCE OR ABSENCE OF INDELS IN 724 00:29:25,871 --> 00:29:27,506 RELATIONSHIP TO EACH OTHER. 725 00:29:27,506 --> 00:29:29,942 SO YOU CAN SEE CLADE 1s, 726 00:29:29,942 --> 00:29:32,778 GENERALLY HAVE THESE COMMON 727 00:29:32,778 --> 00:29:35,414 DELETIONS IN COMPARISON TO THE 728 00:29:35,414 --> 00:29:38,117 OTHER MERBECOVIRUSES AND THAT'S 729 00:29:38,117 --> 00:29:39,685 TRUE FOR ALL THESE CLADES. 730 00:29:39,685 --> 00:29:43,489 SO WE MADE A LARGE PANEL THEN OF 731 00:29:43,489 --> 00:29:45,491 SUED OF PSEUDOTYPES BEARING 732 00:29:45,491 --> 00:29:46,459 DIFFERENT CHIMERIC SPIKES, USED 733 00:29:46,459 --> 00:29:48,861 THEM TO INFECT CELLS. 734 00:29:48,861 --> 00:29:50,863 LOOKING AT 293T CELLS WITHOUT 735 00:29:50,863 --> 00:29:52,565 ANY RECEPTOR, WE'RE NOT SEEING A 736 00:29:52,565 --> 00:29:54,433 LOT OF CLEAR ENTRY, VERY LOW 737 00:29:54,433 --> 00:29:59,939 LEVEL ENTRY OF MERS CORONAVIRUS, 738 00:29:59,939 --> 00:30:03,209 WHICH IS LIKELY BECAUSE 293 Ts 739 00:30:03,209 --> 00:30:05,978 EXPRESS LOW LEVELS OF ACE-2 AND 740 00:30:05,978 --> 00:30:06,412 DPP4. 741 00:30:06,412 --> 00:30:09,815 WHEN WE EXPAND OUR INFECTION TO 742 00:30:09,815 --> 00:30:11,350 INCLUDE CELLS TRANSDUCED WITH 743 00:30:11,350 --> 00:30:12,752 DPP4, ACE-2 OR ANOTHER 744 00:30:12,752 --> 00:30:14,320 CORONAVIRUS RECEPTOR THAT'S 745 00:30:14,320 --> 00:30:17,390 FOUND IN HUMANS, APN, WE CAN SEE 746 00:30:17,390 --> 00:30:20,326 THAT REALLY IT'S JUST THIS BLUE 747 00:30:20,326 --> 00:30:22,294 GROUP OF VIRUSES DOWN HERE, 748 00:30:22,294 --> 00:30:24,263 CLADE 1 VIRUSES, WE'LL CALL 749 00:30:24,263 --> 00:30:26,665 THEM, CAN USE HUMAN DPP4. 750 00:30:26,665 --> 00:30:30,302 WE CAN SHOW THE TWO AFRICAN 751 00:30:30,302 --> 00:30:31,737 MERBECOVIRUSES FOUND IN THAT 752 00:30:31,737 --> 00:30:33,472 NATURE PAPER CAN USE HUMAN 753 00:30:33,472 --> 00:30:36,308 ACE-2, AND REALLY A LOT OF THESE 754 00:30:36,308 --> 00:30:38,844 OTHER CLADES DON'T SEEM TO USE 755 00:30:38,844 --> 00:30:41,347 ANY OF THESE HUMAN ORTHOLOGUES 756 00:30:41,347 --> 00:30:51,857 OF RECEPTOR, TO ORIENT FOR FOR 757 00:30:52,358 --> 00:30:56,462 POSITIVE CONTROLS, 229E WITH 758 00:30:56,462 --> 00:30:56,629 APN. 759 00:30:56,629 --> 00:30:58,964 IF WE ADD TRYPSIN IT'S NOT 760 00:30:58,964 --> 00:31:02,735 GIVING A CLEAR ACKNOWLEDGES. 761 00:31:02,735 --> 00:31:08,974 WE INCLUDED SPECIES ORTHOLOGS OF 762 00:31:08,974 --> 00:31:11,477 NON-RECEPTORS, THIS BAT IS THE 763 00:31:11,477 --> 00:31:13,012 NATURAL HOST FOR HKU5 VIRUSES, 764 00:31:13,012 --> 00:31:21,253 THESE VIRUSES WERE ALL FOUND IN 765 00:31:21,253 --> 00:31:22,755 THESE ABRAMUS BATS. 766 00:31:22,755 --> 00:31:26,959 PINK IS FOUND IN EUROPEAN 767 00:31:26,959 --> 00:31:28,661 HEDGEHOGS, WE WEREN'T ABLE TO 768 00:31:28,661 --> 00:31:29,562 SEE CLEAR ENTRY. 769 00:31:29,562 --> 00:31:32,731 WE CAN SEE A STRONG USE WHEN WE 770 00:31:32,731 --> 00:31:36,001 ADD TRYPSIN OF BAT ACE-2 AMONGST 771 00:31:36,001 --> 00:31:38,003 BAT CORONAVIRUSES, BUT AGAIN NO 772 00:31:38,003 --> 00:31:40,272 REAL CLEAR RECEPTOR PATTERN. 773 00:31:40,272 --> 00:31:43,876 CLADE 4 WAS STILL A QUESTION 774 00:31:43,876 --> 00:31:44,877 MARK. 775 00:31:44,877 --> 00:31:49,148 BUT THIS HKU5 QUESTION WAS NEW. 776 00:31:49,148 --> 00:31:51,450 SO TO VALIDATE THIS STUDY, THIS 777 00:31:51,450 --> 00:31:53,285 EXPERIMENT, WE THEN CHANGED OUR 778 00:31:53,285 --> 00:31:56,288 CELL LINE BACKGROUND TO BABY 779 00:31:56,288 --> 00:31:57,590 HAMSTER KIDNEY CELLS, COMPLETELY 780 00:31:57,590 --> 00:32:02,394 DIFFERENT SPECIES, COMPLETELY 781 00:32:02,394 --> 00:32:06,332 DIFFERENT CELL LINE, DOESN'T 782 00:32:06,332 --> 00:32:08,534 EXPRESS COMPATIBLE FORMS OF 783 00:32:08,534 --> 00:32:13,138 ACE-2 OR DPP4 FOR MERS OR SARS, 784 00:32:13,138 --> 00:32:15,641 WE'RE COULD HAVE DENT WHEN WE 785 00:32:15,641 --> 00:32:21,447 TRANSDUCE WE SEE CLEAR ENTRY OF 786 00:32:21,447 --> 00:32:24,416 HKU 5 COMPLEX WITH THE ACE-2. 787 00:32:24,416 --> 00:32:24,950 SO THAT'S NICE. 788 00:32:24,950 --> 00:32:25,718 CHIMERIC SPIKES. 789 00:32:25,718 --> 00:32:28,554 HOW DO THEY COMPARE TO FULL 790 00:32:28,554 --> 00:32:28,888 LENGTH SPIKES? 791 00:32:28,888 --> 00:32:30,623 AND SO HERE'S A SMALL PANEL 792 00:32:30,623 --> 00:32:33,592 WE'VE MADE, SELECTED A COUPLE OF 793 00:32:33,592 --> 00:32:35,594 DIFFERENT FULL LENGTH SPIKES, 794 00:32:35,594 --> 00:32:37,229 AND WE'RE SHOWING FOR EXAMPLE 795 00:32:37,229 --> 00:32:39,565 FULL LENGTH SPIKE FROM HKU ^5 20 796 00:32:39,565 --> 00:32:50,042 IS ABLE TO INFECT CELLS THAT 797 00:32:54,780 --> 00:32:56,582 SPECIAL PIPISTRELLIS ABRAMUS. 798 00:32:56,582 --> 00:32:57,917 THAT'S CHIMERIC SPIKE, WHO ABOUT 799 00:32:57,917 --> 00:32:58,684 WHOLE VIRUS? 800 00:32:58,684 --> 00:33:02,054 WE PAIRED UP WITH RALPH'S GROUP 801 00:33:02,054 --> 00:33:06,458 AT UNC, SPECIALIZES IN PRODUCING 802 00:33:06,458 --> 00:33:07,259 REPLICATION COMPETENT MOLECULAR 803 00:33:07,259 --> 00:33:10,362 CLONES OF CORONAVIRUSES, THEY 804 00:33:10,362 --> 00:33:11,697 HAVE AN HKU 5 IN THEIR 805 00:33:11,697 --> 00:33:13,032 COLLECTION THEY HAVEN'T BEEN 806 00:33:13,032 --> 00:33:15,534 ABLE TO GROW. 807 00:33:15,534 --> 00:33:19,138 THE IDEA WAS SIMILARITY TO MERS 808 00:33:19,138 --> 00:33:19,905 WAS WORTH PRODUCING AND THOUGHT 809 00:33:19,905 --> 00:33:24,276 THEY WORK ABLE -- WOULD BE ABLO 810 00:33:24,276 --> 00:33:26,245 GET IT TO HE REPLICATE BUT 811 00:33:26,245 --> 00:33:26,912 WITHOUT RECEPTOR IDENTITY IT 812 00:33:26,912 --> 00:33:29,214 WASN'T ABLE TO GROW. 813 00:33:29,214 --> 00:33:35,120 I SENT CELL LINES, TRANSDUCED 814 00:33:35,120 --> 00:33:37,523 WITH PIPISTRELLUS ABRAMUS ACE-2, 815 00:33:37,523 --> 00:33:42,861 NICELY SUPPORT REPLICATION OF 816 00:33:42,861 --> 00:33:44,496 THEIR GFP EXPRESSING MOLECULAR 817 00:33:44,496 --> 00:33:52,504 CLONE, CAN -- WE CAN DETECT 818 00:33:52,504 --> 00:33:55,240 ACCUMULATION OF VIRAL PROTEINS 819 00:33:55,240 --> 00:34:01,046 DURING REPLICATION SUGGESTING 820 00:34:01,046 --> 00:34:02,014 ACE-2 IS SUPPORTING REPLICATION. 821 00:34:02,014 --> 00:34:06,986 TAKING A CLOSE YOU ARE LOOK AT 822 00:34:06,986 --> 00:34:10,222 HKU5, IT HAS A LOT OF DIVERSITY, 823 00:34:10,222 --> 00:34:14,927 NOT JUST FROM OTHER CLADES IN 824 00:34:14,927 --> 00:34:17,329 THE MERBECOVIRUSES BUT WITHIN 825 00:34:17,329 --> 00:34:17,796 ITSELF. 826 00:34:17,796 --> 00:34:20,633 I'M SHOWING CONTACT POINTS 827 00:34:20,633 --> 00:34:23,135 IDENTIFIED BETWEEN THE AFRICAN 828 00:34:23,135 --> 00:34:24,870 ACE-2 USING MERBECOVIRUSESS WITH 829 00:34:24,870 --> 00:34:26,538 HUMAN AND BAT ACE-2, BUT IF WE 830 00:34:26,538 --> 00:34:33,212 LOOK AT RESIDUES IN HKU5 ALMOST 831 00:34:33,212 --> 00:34:34,413 EVERYONE IS DIFFERENT. 832 00:34:34,413 --> 00:34:36,482 WE'RE NOT ALWAYS ABLE TO USE THE 833 00:34:36,482 --> 00:34:38,984 DATA FROM EVEN ONE CLADE TO 834 00:34:38,984 --> 00:34:40,419 PREDICT PHENOTYPE OF ANOTHER. 835 00:34:40,419 --> 00:34:42,621 BECAUSE THESE VIRUSES CAN USE 836 00:34:42,621 --> 00:34:43,822 REALLY WIDELY DIFFERENT 837 00:34:43,822 --> 00:34:45,691 INTERACTING SURFACES WITH THESE 838 00:34:45,691 --> 00:34:46,525 PROTEINS. 839 00:34:46,525 --> 00:34:48,961 AND TO MAKE IT EVEN MORE 840 00:34:48,961 --> 00:34:50,929 CHALLENGING HALF CONTACT POINTS 841 00:34:50,929 --> 00:34:53,899 ARE IN A DELETION, A LOOP 842 00:34:53,899 --> 00:34:56,969 DELETION BASICALLY ON THE 843 00:34:56,969 --> 00:34:57,169 HKU5s. 844 00:34:57,169 --> 00:35:00,272 SO THERE'S SOMETHING DIFFERENT 845 00:35:00,272 --> 00:35:01,240 GOING ON THERE. 846 00:35:01,240 --> 00:35:03,208 SO TAKING A CLOSER LOOK AT THE 847 00:35:03,208 --> 00:35:09,214 STRUCTURAL DATA, THIS IS THE 848 00:35:09,214 --> 00:35:10,883 CRYSTAL STRUCTURE FOR ONE OF THE 849 00:35:10,883 --> 00:35:12,518 AFRICAN MERBECOVIRUSES WITH BAT 850 00:35:12,518 --> 00:35:19,525 ACE-2, THIS IS A PREDICTED 851 00:35:19,525 --> 00:35:23,896 STRUCK FEWER FOR PIPISTRELLIS 852 00:35:23,896 --> 00:35:25,531 ACE-2 AND HKU5, AND WE CAN SEE 853 00:35:25,531 --> 00:35:28,267 FOR THE VIRUSES THAT HAVE AN 854 00:35:28,267 --> 00:35:31,637 INTACT SERIES OF BOTH OF THOSE 855 00:35:31,637 --> 00:35:32,971 LOOPS WITHOUT ANY DELETIONS, CAN 856 00:35:32,971 --> 00:35:35,074 LOOK SIMILAR, BUT FOR THE VIRUS 857 00:35:35,074 --> 00:35:36,909 THAT HAS THAT DELETION IN ITS 858 00:35:36,909 --> 00:35:37,810 LOOP IT'S ACTUALLY CONTRACTED 859 00:35:37,810 --> 00:35:40,979 AWAY FROM THE SURFACE. 860 00:35:40,979 --> 00:35:45,584 SO POTENTIALLY HAS LESS CONTACT 861 00:35:45,584 --> 00:35:46,885 WITH ACE-2. 862 00:35:46,885 --> 00:35:48,854 SO, TO STUDY THESE LOOPS AND 863 00:35:48,854 --> 00:35:50,489 THEIR EFFECT ON ENTRY A LITTLE 864 00:35:50,489 --> 00:35:53,192 BIT MORE WE SELECTED TWO 865 00:35:53,192 --> 00:35:54,960 CRITICAL RESIDUES, BASICALLY IN 866 00:35:54,960 --> 00:35:57,296 THE MIDDLE OF THOSE LOOPS, 867 00:35:57,296 --> 00:35:58,597 INTRODUCED A SERIES OF LARGE 868 00:35:58,597 --> 00:36:03,702 BULKY AND CHARGED AMINO ACIDS 869 00:36:03,702 --> 00:36:05,637 AND MUTAGENESIS STUDY, TESTED 870 00:36:05,637 --> 00:36:12,945 ENTRY OF MUTANT RECEPTOR BINDING 871 00:36:12,945 --> 00:36:16,882 DOMAINS ON CELLS EXPRESSING 872 00:36:16,882 --> 00:36:18,851 PIPISTRELLIS ABRAMU, OR HUMAN 873 00:36:18,851 --> 00:36:22,154 ACE-2, HUMAN AND MA'AM CENTER 874 00:36:22,154 --> 00:36:24,189 CELLS TO ELIMINATE CELL LINE 875 00:36:24,189 --> 00:36:25,224 SPECIFIC DIFFERENCES HOPING TO 876 00:36:25,224 --> 00:36:27,192 SEE DIFFERENCES ACROSS BOTH CELL 877 00:36:27,192 --> 00:36:28,894 LINES REGARDLESS OF SPECIES 878 00:36:28,894 --> 00:36:32,998 BACKGROUNDS SO WE CAN MORE 879 00:36:32,998 --> 00:36:34,066 FIRMLY SAY WHERE THE PHENOTYPE 880 00:36:34,066 --> 00:36:34,933 IS COMING FROM. 881 00:36:34,933 --> 00:36:37,136 THIS IS A HEAT MAP SHOWING 882 00:36:37,136 --> 00:36:40,305 ENTHIS TRY DATA IN COMPARISON 883 00:36:40,305 --> 00:36:44,376 D. -- ENTRY DATA IN COMPARISON. 884 00:36:44,376 --> 00:36:46,111 WHEN WE INTRODUCE MUTATIONS IN 885 00:36:46,111 --> 00:36:50,616 LOOP 1 OR LOOP 2 FOR EITHER THE 886 00:36:50,616 --> 00:36:51,483 TWO-LOOP VIRUS OR ONE-LOOP VIRUS 887 00:36:51,483 --> 00:36:53,385 THEY ALL TAKE A HIT IN ABILITY 888 00:36:53,385 --> 00:37:01,560 TO INFECT CELLS THAT ARE 889 00:37:01,560 --> 00:37:03,662 EXPRESSING PIPISTRELLIS ABRAMUS 890 00:37:03,662 --> 00:37:09,234 BAT ACE-2 REGARDLESS OF CELL 891 00:37:09,234 --> 00:37:10,235 LINE BACKGROUND, STRONGER IF WE 892 00:37:10,235 --> 00:37:11,203 MUTATE THE SECOND LOOK, THAT 893 00:37:11,203 --> 00:37:12,871 MIGHT BE A CRITICAL POINT FOR 894 00:37:12,871 --> 00:37:13,172 INTERACTION. 895 00:37:13,172 --> 00:37:14,807 THE STORY IS QUITE DIFFERENT 896 00:37:14,807 --> 00:37:18,110 WHEN WE TEST THIS MUTANT SET ON 897 00:37:18,110 --> 00:37:18,777 HUMAN ACE-2. 898 00:37:18,777 --> 00:37:20,612 NOW WE CAN SEE THE VIRUS THAT 899 00:37:20,612 --> 00:37:23,248 HAS TWO LOOPS IS ACTUALLY ABLE 900 00:37:23,248 --> 00:37:24,783 TO GAIN AN INCREASE IN ITS 901 00:37:24,783 --> 00:37:27,186 ABILITY TO INFECT CELLS 902 00:37:27,186 --> 00:37:28,720 EXPRESSING HUMAN ACE-2. 903 00:37:28,720 --> 00:37:30,389 THE OTHER VIRUS THAT ONLY HAS 904 00:37:30,389 --> 00:37:31,790 ONE LOOP DOESN'T SEEM TO HAVE 905 00:37:31,790 --> 00:37:32,658 THAT SAME EFFECT. 906 00:37:32,658 --> 00:37:36,495 IT MIGHT BE THAT THE LARGER LOOP 907 00:37:36,495 --> 00:37:38,497 IN THIS INTERFACE MAY ALLOW THIS 908 00:37:38,497 --> 00:37:41,099 VIRUS TO ADAPT BETTER TO OTHER 909 00:37:41,099 --> 00:37:41,433 ACE-2s. 910 00:37:41,433 --> 00:37:42,868 SO WHAT WE'RE LEARNING FROM THIS 911 00:37:42,868 --> 00:37:46,471 IS WE NEED BETTER STRUCTURE AND 912 00:37:46,471 --> 00:37:47,005 DEEP SCANNING MUTAGENESIS 913 00:37:47,005 --> 00:37:48,540 STUDIES TO UNDERSTAND THE 914 00:37:48,540 --> 00:37:49,641 FLEXIBILITY OF THIS INTERFACE. 915 00:37:49,641 --> 00:37:51,410 AND SO WE'RE WORKING ON THAT. 916 00:37:51,410 --> 00:37:54,479 WE HAVE A COLLABORATION WITH 917 00:37:54,479 --> 00:37:56,348 PAMELA YORKMAN'S GROUP AT CAL 918 00:37:56,348 --> 00:37:59,017 TECH, AND WE'VE BEEN ABLE TO 919 00:37:59,017 --> 00:38:00,219 PRODUCE THE FIRST CryoEM 920 00:38:00,219 --> 00:38:03,722 STRUCTURE OF THE WHOLE HKU520 921 00:38:03,722 --> 00:38:06,859 SPIKE, WITH BOTH OF THE LARGE 922 00:38:06,859 --> 00:38:09,962 LOOPS, ONE OF THE PROTOTYPICAL 923 00:38:09,962 --> 00:38:13,565 HKU 5s IN LITERATURE IS HKU 924 00:38:13,565 --> 00:38:15,701 5-1, BASICALLY THE FIRST 925 00:38:15,701 --> 00:38:18,804 SEQUENCE, THAT WAS DESCRIBED. 926 00:38:18,804 --> 00:38:25,310 HKU 5-1 WAS HUNDRED LOOP, 927 00:38:25,310 --> 00:38:26,378 IMPORTANT TO UNDERSTAND POSSIBLE 928 00:38:26,378 --> 00:38:29,147 DISTINCTION BETWEEN VIRUSES THAT 929 00:38:29,147 --> 00:38:31,116 MAY IMPROVE THEIR CROSS-SPECIES 930 00:38:31,116 --> 00:38:31,750 TRANSMISSION POTENTIAL. 931 00:38:31,750 --> 00:38:35,153 WE'VE BEEN ABLE TO SHOW REALLY 932 00:38:35,153 --> 00:38:37,990 SIMILAR TO OTHER BAT 933 00:38:37,990 --> 00:38:41,393 CORONAVIRUSES THIS BAT HAS AN 934 00:38:41,393 --> 00:38:44,363 ALL HVDs DOWN CONFIRMATION IN 935 00:38:44,363 --> 00:38:44,763 OUR ASSAYS. 936 00:38:44,763 --> 00:38:46,531 TO UNDERSTAND A LITTLE BIT MORE 937 00:38:46,531 --> 00:38:48,600 WHAT MAKES THESE CLADES THE WAY 938 00:38:48,600 --> 00:38:51,169 THEY ARE, WE'VE MADE DIFFERENT 939 00:38:51,169 --> 00:38:51,603 CONSENSUS SEQUENCES 940 00:38:51,603 --> 00:38:53,238 REPRESENTATIVE OF EACH OF THE 941 00:38:53,238 --> 00:38:54,539 FOUR DIFFERENT CLADES, AT LEAST 942 00:38:54,539 --> 00:38:56,174 THE CLADES WE HAVE MORE THAN TWO 943 00:38:56,174 --> 00:38:56,742 SEQUENCES FOR. 944 00:38:56,742 --> 00:38:59,811 AND THEN WE CAN TEST THEM IN OUR 945 00:38:59,811 --> 00:39:01,313 CHIMERIC SPIKE BACKBONE. 946 00:39:01,313 --> 00:39:04,616 AND SO WE CAN SHOW THAT CHIMERIC 947 00:39:04,616 --> 00:39:06,585 SPIKE WITH CONSENSUS CLADE 1 RBD 948 00:39:06,585 --> 00:39:09,521 CAN INFECT CELLS WITH HUMAN 949 00:39:09,521 --> 00:39:11,823 DPP4, CLADE 2 RECEPTOR BINDING 950 00:39:11,823 --> 00:39:15,093 DOMAIN CAN INFECT WITH THE BAT 951 00:39:15,093 --> 00:39:15,494 ACE-2. 952 00:39:15,494 --> 00:39:18,330 BUT NOT WITH THE HUMAN ACE-2. 953 00:39:18,330 --> 00:39:21,233 WHEREAS THE CLADE 3 GROUP CAN 954 00:39:21,233 --> 00:39:24,102 ACTUALLY INTERACT WITH BOTH, 955 00:39:24,102 --> 00:39:26,405 WHICH IS IN AGREEMENT, CLOSE 956 00:39:26,405 --> 00:39:29,241 AGREEMENT WITH PREVIOUS STUDY IN 957 00:39:29,241 --> 00:39:29,574 "NATURE." 958 00:39:29,574 --> 00:39:32,411 AND OUR CLADE 4 DOESN'T USE 959 00:39:32,411 --> 00:39:33,845 THESE RECEPTOR MOLECULES. 960 00:39:33,845 --> 00:39:36,682 WE'VE BEEN ABLE TO BREAK DOWN 961 00:39:36,682 --> 00:39:47,192 THE MERBECOVIRUSES, IT'S THE 962 00:39:47,693 --> 00:39:50,062 PRESENCE OF INDELS AND 963 00:39:50,062 --> 00:39:51,363 SEQUENCE-SPECIFIC MOTIFS AND 964 00:39:51,363 --> 00:39:55,434 ENTRY PHENOTYPE THAT DEFINE 965 00:39:55,434 --> 00:39:57,169 THESE FUNCTIONAL CLADES, WE 966 00:39:57,169 --> 00:39:58,236 CAPTAIN MAKE THESE 967 00:39:58,236 --> 00:40:00,005 DETERMINATIONS FROM GEOGRAPHIC 968 00:40:00,005 --> 00:40:03,008 ORIGIN FOR EXAMPLE, SOME RBDs 969 00:40:03,008 --> 00:40:04,476 HAVE FOUND ACROSS A WIDE 970 00:40:04,476 --> 00:40:07,112 GEOGRAPHIC RANGE TELLING US 971 00:40:07,112 --> 00:40:08,647 THERE'S A SAMPLING BIAS IN THE 972 00:40:08,647 --> 00:40:08,947 LITERATURE. 973 00:40:08,947 --> 00:40:10,048 THE MORE WE LOOK FOR THESE 974 00:40:10,048 --> 00:40:12,250 VIRUSES, THE MORE WE'RE GOING TO 975 00:40:12,250 --> 00:40:16,855 FIND ACROSS A WIDER RANGE OF 976 00:40:16,855 --> 00:40:20,792 SPECIES AND GEOGRAPHIC 977 00:40:20,792 --> 00:40:23,862 LOCATIONS. 978 00:40:23,862 --> 00:40:31,203 SO HKU 4 AND 4 AND 5 WERE DISCD 979 00:40:31,203 --> 00:40:32,471 SIX YEARS BEFORE CORONAVIRUS, WE 980 00:40:32,471 --> 00:40:34,673 DIDN'T KNOW WHAT TYPE OF 981 00:40:34,673 --> 00:40:36,908 RECEPTOR THEY USED, DIDN'T KNOW 982 00:40:36,908 --> 00:40:45,784 SPILLOVER PRO PRO TENSION. 983 00:40:45,784 --> 00:40:46,084 POTENTIAL. 984 00:40:46,084 --> 00:40:47,519 GROUPS STARTED GOING BACK AND 985 00:40:47,519 --> 00:40:49,921 FINDING CLOSELY RELATED BAT 986 00:40:49,921 --> 00:40:54,826 SEQUENCES, HKU 4 AND 5 LOOKED 987 00:40:54,826 --> 00:40:56,495 SIMILAR TO MERS, ONLY ONE COULD 988 00:40:56,495 --> 00:40:57,929 EAST THE SAME RECEPTORS, THE 989 00:40:57,929 --> 00:40:59,898 OTHER COULDN'T. 990 00:40:59,898 --> 00:41:01,299 IN THIS STUDY THEY ARE ONLY 991 00:41:01,299 --> 00:41:06,638 LOOKING AT HUMAN AND ONE BAT 992 00:41:06,638 --> 00:41:10,042 VARIANT OF DPP4, SO PROBABLY 993 00:41:10,042 --> 00:41:11,810 MISSED THAT. 994 00:41:11,810 --> 00:41:13,512 AFTER RALPH'S GROUP DEVELOPED 995 00:41:13,512 --> 00:41:14,780 MOLECULAR CLONE IF YOU ADDED 996 00:41:14,780 --> 00:41:16,948 TRYPSIN YOU COULD GET THE VIRUS 997 00:41:16,948 --> 00:41:18,817 TO REPLICATE ON DIFFERENT CELL 998 00:41:18,817 --> 00:41:20,452 LINES BUT WEREN'T ABLE TO PIN 999 00:41:20,452 --> 00:41:22,421 RECEPTOR DOWN BECAUSE THEY ONLY 1000 00:41:22,421 --> 00:41:23,955 LOOKED AT DIFFERENT SPECIES 1001 00:41:23,955 --> 00:41:25,724 VARIANTS OF DPP4 AND ONLY 1002 00:41:25,724 --> 00:41:28,894 INCLUDED TRYPSIN IN THEIR ASSAY, 1003 00:41:28,894 --> 00:41:31,730 AGAIN MISSING IT. 1004 00:41:31,730 --> 00:41:33,498 IN 2022 WE LEARNED 1005 00:41:33,498 --> 00:41:37,102 MERBECOVIRUSES TO USE ACE-2, 1006 00:41:37,102 --> 00:41:39,271 MORE SPECIFICALLY HUMAN ACE-2, 1007 00:41:39,271 --> 00:41:41,807 THIS STUDY TESTED ACE-2 FROM 44 1008 00:41:41,807 --> 00:41:43,341 BAT SPECIES WITH HKU5 AND SOME 1009 00:41:43,341 --> 00:41:48,814 OTHERS, BUT THEY DIDN'T ACTUALLY 1010 00:41:48,814 --> 00:41:50,582 TEST PIPISTRELLIS ABRAMUS BAT, 1011 00:41:50,582 --> 00:42:00,292 SO RECEPTOR WAS ELUSIVE, 1012 00:42:00,292 --> 00:42:01,660 ENORMOUS SPECIES SPECIFICITY. 1013 00:42:01,660 --> 00:42:04,930 WE'VE SHOWN RBD IS FLANKED BY 1014 00:42:04,930 --> 00:42:07,766 TWO HIGHLY CONSERVED GLYCINES, A 1015 00:42:07,766 --> 00:42:09,201 GUIDE TO MAKE CHIMERIC SPIKES 1016 00:42:09,201 --> 00:42:13,572 AND SCREEN THE ENTIRE SUBGENUS, 1017 00:42:13,572 --> 00:42:16,208 PUBLISH DIVERSITY OF SUBGENUS 1018 00:42:16,208 --> 00:42:18,276 FOR ABILITY TO INFECT DIFFERENT 1019 00:42:18,276 --> 00:42:18,944 CELL LINES, USE DIFFERENT 1020 00:42:18,944 --> 00:42:21,346 RECEPTORS, SHOW THEY SORT INTO 1021 00:42:21,346 --> 00:42:22,681 DIFFERENT CLADES BASED OFF THEIR 1022 00:42:22,681 --> 00:42:23,181 SEQUENCE. 1023 00:42:23,181 --> 00:42:25,517 WE'RE ABLE TO CONFIRM CLADE 1 1024 00:42:25,517 --> 00:42:28,587 VIRUSES ALL USE DPP4, CLADE 3 1025 00:42:28,587 --> 00:42:30,355 CAN USE ACE-2. 1026 00:42:30,355 --> 00:42:33,091 HERE WE SHOWED CLADE 2 CAN ALSO 1027 00:42:33,091 --> 00:42:34,726 USE ACE-2, MORE SPECIES FASHION 1028 00:42:34,726 --> 00:42:36,128 AND CLADE 4 DOESN'T SEEM TO USE 1029 00:42:36,128 --> 00:42:40,031 ANY OF THESE KNOWN RECEPTORS. 1030 00:42:40,031 --> 00:42:41,233 SO, WE SHOWED DIFFERENT 1031 00:42:41,233 --> 00:42:44,402 MUTATIONS IN THE INTERFACE CAN 1032 00:42:44,402 --> 00:42:48,240 INFLUENCE THE RBD ABILITY TO USE 1033 00:42:48,240 --> 00:42:49,341 DIFFERENT ACE-2. 1034 00:42:49,341 --> 00:42:51,643 AND THEN JUST RECENTLY IN AUGUST 1035 00:42:51,643 --> 00:42:57,349 THIS YEAR STUDY CAME OUT WHERE 1036 00:42:57,349 --> 00:43:01,386 RESEARCHERS LOOKED ACROSS 1037 00:43:01,386 --> 00:43:05,323 BASICALLY FARMS, ANIMAL FARMS 1038 00:43:05,323 --> 00:43:07,025 ACROSS CHINA LOOKING AT DECEASED 1039 00:43:07,025 --> 00:43:09,261 ANIMALS THAT SEEM TO FIND FROM 1040 00:43:09,261 --> 00:43:13,098 DISEASE AND HKU5 WAS FOUND IN 1041 00:43:13,098 --> 00:43:18,136 SEVERAL DEAD MINK, WE'RE SEEING 1042 00:43:18,136 --> 00:43:18,904 ACROSS-SPECIES TRANSMISSION 1043 00:43:18,904 --> 00:43:24,276 EVENTS, ALL HAD SIMILAR VIRAL 1044 00:43:24,276 --> 00:43:29,714 SEQUENCE, AND VIRAL SEQUENCE ARE 1045 00:43:29,714 --> 00:43:33,151 THE TWO LOOP RBDs, PERHAPS THE 1046 00:43:33,151 --> 00:43:36,521 BIGGER RBD LOOPS ALLOW VIRUSES 1047 00:43:36,521 --> 00:43:37,956 TO TRANSMIT A LITTLE BIT BETTER. 1048 00:43:37,956 --> 00:43:39,691 THIS IS EARLY PRELIMINARY DATA 1049 00:43:39,691 --> 00:43:41,459 WHERE WE MADE CHIMERIC SPIKE, 1050 00:43:41,459 --> 00:43:42,861 CONTINUING OUR SURVEILLANCE 1051 00:43:42,861 --> 00:43:44,930 EFFORTS WE CAN CLONE THIS MINK 1052 00:43:44,930 --> 00:43:47,032 RECEPTOR BINDING DOMAIN INTO THE 1053 00:43:47,032 --> 00:43:48,900 CHIMERIC SPIKE AND TEST ENTRY ON 1054 00:43:48,900 --> 00:43:50,669 CELLS THAT EXPRESS MINK ACE-2 OR 1055 00:43:50,669 --> 00:43:54,472 HUMAN AILS 2, WE CAN NICELY 1056 00:43:54,472 --> 00:43:57,876 VERIFY THIS HKU5 USES MINK 1057 00:43:57,876 --> 00:43:59,110 ACE-2, WITH SIMILAR EFFICIENCY 1058 00:43:59,110 --> 00:44:00,946 AS SARS IF NOT BETTER. 1059 00:44:00,946 --> 00:44:03,582 BUT THAT IT HAS VERY LIMITED 1060 00:44:03,582 --> 00:44:06,418 ABILITY TO INFECT CELLS 1061 00:44:06,418 --> 00:44:08,253 EXPRESSING HUMAN ACE-2, SO EVEN 1062 00:44:08,253 --> 00:44:09,688 WHEN WE ADD TRYPSIN WE'RE NOT 1063 00:44:09,688 --> 00:44:13,391 GETTING A CLEAR STRONG SIGNAL. 1064 00:44:13,391 --> 00:44:17,028 BUT MAYBE A LITTLE BIT. 1065 00:44:17,028 --> 00:44:19,097 NOW AS OUR STUDY COMES OUT 1066 00:44:19,097 --> 00:44:22,067 SEVERAL GROUPS ARE WORKING ON 1067 00:44:22,067 --> 00:44:26,905 HKU 5, A GROUP HAS SHOWN THERE'S 1068 00:44:26,905 --> 00:44:29,474 AN HKU5 -- BASICALLY AN EXTRA 1069 00:44:29,474 --> 00:44:31,910 LINEAGE OF HKU 5 SEQUENCES, THEY 1070 00:44:31,910 --> 00:44:34,746 HAVE TAKEN A DEEPER DIVE INTO 1071 00:44:34,746 --> 00:44:37,048 THEIR SAMPLE DATABASE AND FOUND 1072 00:44:37,048 --> 00:44:38,817 HKU 5 VARIANTS THAT FORM A 1073 00:44:38,817 --> 00:44:40,986 DIFFERENT BRANCH ON THE TREE 1074 00:44:40,986 --> 00:44:44,289 THAT MAY HAVE IMPROVED OR HIGHER 1075 00:44:44,289 --> 00:44:45,523 ABILITY TO USE HUMAN ACE-2. 1076 00:44:45,523 --> 00:44:48,560 SO IT'S PRETTY LOW IN THIS ASSAY 1077 00:44:48,560 --> 00:44:49,894 STILL I THINK, BUT WHAT WE'RE 1078 00:44:49,894 --> 00:44:53,932 SEEING IS THAT THERE IS A WIDE 1079 00:44:53,932 --> 00:44:56,234 DISTRIBUTION OF ACE-2 USING 1080 00:44:56,234 --> 00:44:57,969 VIRUSES, THEY CAN USE DIFFERENT 1081 00:44:57,969 --> 00:44:59,104 REGIONS OF ACE-2 FOR THEIR 1082 00:44:59,104 --> 00:45:01,273 INTERACTIONS SO IT'S NOT LIKE 1083 00:45:01,273 --> 00:45:03,041 THEY ARE BINDING TO ONE 1084 00:45:03,041 --> 00:45:04,676 CONSERVED REGION WHICH IS WHY 1085 00:45:04,676 --> 00:45:06,511 INTERFACES CAN LOOK SO DIFFERENT 1086 00:45:06,511 --> 00:45:09,047 BUT REALLY FINDING VIRUSES WITH 1087 00:45:09,047 --> 00:45:10,048 EVEN TRACE POTENTIAL TO INFECT 1088 00:45:10,048 --> 00:45:11,549 CELLS IS A CONCERN. 1089 00:45:11,549 --> 00:45:13,885 SO WE SHOWED SEVERAL YEARS AGO 1090 00:45:13,885 --> 00:45:16,721 THAT MERS WAS CAPABLE OF REALLY 1091 00:45:16,721 --> 00:45:17,922 QUICKLY ADAPTING IN CELL CULTURE 1092 00:45:17,922 --> 00:45:20,859 TO A VIRUS EXPRESSING A 1093 00:45:20,859 --> 00:45:23,194 SUBOPTIMAL VARIANT OF DPP4, SO 1094 00:45:23,194 --> 00:45:27,766 WITHIN THREE PASSAGES THE VIRUS 1095 00:45:27,766 --> 00:45:32,570 PICKED UP ONE NUCLEOOH TIED 1096 00:45:32,570 --> 00:45:33,905 CHANGE CHANGING ITS ABILITY TO 1097 00:45:33,905 --> 00:45:39,778 REPLICATE ON A CELLS EXPRESSING 1098 00:45:39,778 --> 00:45:41,546 DPP4 FROM CON COGNATE SPECIES, 1099 00:45:41,546 --> 00:45:43,615 CAUSE FOR CONCERN. 1100 00:45:43,615 --> 00:45:45,917 WE'RE WORKING ON STRUCTURAL 1101 00:45:45,917 --> 00:45:50,989 EXPLORATION WITH PAMELA 1102 00:45:50,989 --> 00:45:53,058 BJORKMAN'S GROUP, DEEP 1103 00:45:53,058 --> 00:45:58,997 MUTAGENESIS WITH TYLER STARR'S 1104 00:45:58,997 --> 00:46:01,166 LAB AND PURSUING WORK WITH 1105 00:46:01,166 --> 00:46:01,733 MERBECOVIRUSES. 1106 00:46:01,733 --> 00:46:04,436 BARBARA HAHN IS USING MACHINE 1107 00:46:04,436 --> 00:46:07,005 LEARNING APPROACHES, CAN WE USE 1108 00:46:07,005 --> 00:46:09,641 THIS TO PREDICT DIFFERENT 1109 00:46:09,641 --> 00:46:10,141 PHENOTYPES. 1110 00:46:10,141 --> 00:46:13,645 AND SO WITH THAT I'D LIKE TO 1111 00:46:13,645 --> 00:46:19,117 THANK MY COLLABORATORS, THAT 1112 00:46:19,117 --> 00:46:22,487 HELPED US WITH THIS MERBECOVIRUS 1113 00:46:22,487 --> 00:46:23,088 WORK. 1114 00:46:23,088 --> 00:46:25,357 AND I WILL TAKE YOUR QUESTIONS. 1115 00:46:25,357 --> 00:46:26,791 >> THANKS, MICHAEL, THAT WAS A 1116 00:46:26,791 --> 00:46:29,160 WONDERFUL TALK. 1117 00:46:29,160 --> 00:46:32,564 THERE ARE LOTS OF QUESTIONS I 1118 00:46:32,564 --> 00:46:34,165 THINK. 1119 00:46:34,165 --> 00:46:36,835 AND I THINK THAT I COULDN'T STOP 1120 00:46:36,835 --> 00:46:38,269 THINKING OF QUESTIONS ACTUALLY 1121 00:46:38,269 --> 00:46:39,771 THROUGHOUT THAT TALK. 1122 00:46:39,771 --> 00:46:41,639 YOU INTRODUCED SO MANY ASPECTS 1123 00:46:41,639 --> 00:46:44,075 THAT COULD GENERATE INTERESTING 1124 00:46:44,075 --> 00:46:46,177 RESULTS IN THE FUTURE. 1125 00:46:46,177 --> 00:46:48,012 SO I'LL START BY ASKING A COUPLE 1126 00:46:48,012 --> 00:46:48,680 QUESTIONS. 1127 00:46:48,680 --> 00:46:52,517 BEFORE I DO THAT I WANT TO 1128 00:46:52,517 --> 00:46:55,353 REMIND THE AUDIENCE PLEASE ASK 1129 00:46:55,353 --> 00:46:56,654 YOUR QUESTIONS NOW BY CLICKING 1130 00:46:56,654 --> 00:46:59,290 ON THE SEND LIVE FEEDBACK 1131 00:46:59,290 --> 00:47:00,191 BUTTON, WHICH IS RIGHT IN THE 1132 00:47:00,191 --> 00:47:02,727 CENTER OF THE SCREEN UNDER THE 1133 00:47:02,727 --> 00:47:04,796 VIDEO, NIH VIDEOCAST SITE. 1134 00:47:04,796 --> 00:47:05,697 WE'LL RECEIVE THOSE QUESTIONS 1135 00:47:05,697 --> 00:47:09,501 AND RELAY THEM TO THE SPEAKER. 1136 00:47:09,501 --> 00:47:11,069 I WANTED TO ASK BECAUSE YOU 1137 00:47:11,069 --> 00:47:16,841 MENTIONED SOME OF YOUR FUTURE 1138 00:47:16,841 --> 00:47:20,445 DIRECTIONS ABOUT USING 1139 00:47:20,445 --> 00:47:20,912 MUTAGENESIS, SCANNING 1140 00:47:20,912 --> 00:47:23,281 MUTAGENESIS, TO UNDERSTAND MORE 1141 00:47:23,281 --> 00:47:24,916 ABOUT THE RBD AND RECEPTOR 1142 00:47:24,916 --> 00:47:25,250 USAGE. 1143 00:47:25,250 --> 00:47:27,786 SO DO YOU THINK THAT YOU WILL 1144 00:47:27,786 --> 00:47:30,488 MOVE INTO AN AREA WHERE YOU CAN 1145 00:47:30,488 --> 00:47:33,024 PLAN TO PREDICT WHICH RESIDUES 1146 00:47:33,024 --> 00:47:35,960 WOULD GIVE AN EXISTING RBD THE 1147 00:47:35,960 --> 00:47:37,061 POTENTIAL TO USE HUMAN ACE-2? 1148 00:47:37,061 --> 00:47:40,298 >> YEAH, I THINK THAT'S ONE OF 1149 00:47:40,298 --> 00:47:42,333 THE LARGER GOALS. 1150 00:47:42,333 --> 00:47:45,970 SO, YOU KNOW, TYLER STAR'S GROUP 1151 00:47:45,970 --> 00:47:49,674 HAS PIONEERED MUTAGENESIS 1152 00:47:49,674 --> 00:47:52,177 APPROACH WITH THE 1153 00:47:52,177 --> 00:47:52,544 SARBECOVIRUSES. 1154 00:47:52,544 --> 00:47:53,144 INITIAL CHARACTERIZATION OF 1155 00:47:53,144 --> 00:47:54,045 PANELS GAVE US INFORMATION IN 1156 00:47:54,045 --> 00:47:57,549 THE EARLY COVID DAYS ABOUT 1157 00:47:57,549 --> 00:47:58,817 RESIDUES THAT MIGHT EMERGE FOR 1158 00:47:58,817 --> 00:48:00,618 VACCINE RESISTANCE FOR EXAMPLE 1159 00:48:00,618 --> 00:48:02,287 AND ABILITY TO EVADE ANTIBODY 1160 00:48:02,287 --> 00:48:02,821 RESPONSE. 1161 00:48:02,821 --> 00:48:04,055 SO, YEAH, I THINK THAT KIND OF 1162 00:48:04,055 --> 00:48:06,791 APPROACH HAS A LOT OF POWER TO 1163 00:48:06,791 --> 00:48:07,091 IT. 1164 00:48:07,091 --> 00:48:09,294 AND SO I THINK ONE OF OUR BIGGER 1165 00:48:09,294 --> 00:48:12,263 GOALS IS TO AGGREGATE AND BUILD 1166 00:48:12,263 --> 00:48:14,866 DATA THAT'S ALL KIND OF IN A 1167 00:48:14,866 --> 00:48:16,334 SIMILAR PLATFORM BACKGROUND SO 1168 00:48:16,334 --> 00:48:19,370 WE HAVE A LOT OF COMPARABILITY 1169 00:48:19,370 --> 00:48:21,473 BETWEEN EXPERIMENTS, SO OUR 1170 00:48:21,473 --> 00:48:22,874 MODELS CAN BE A LOT MORE 1171 00:48:22,874 --> 00:48:23,208 ACCURATE. 1172 00:48:23,208 --> 00:48:25,844 THE IDEA I THINK IS TO DO THESE 1173 00:48:25,844 --> 00:48:27,812 MUTAGENESIS SCREENS AND THEN 1174 00:48:27,812 --> 00:48:29,747 FEED THAT TO OUR COMPUTATIONAL 1175 00:48:29,747 --> 00:48:32,617 TEAM TO HELP -- YOU KNOW, I 1176 00:48:32,617 --> 00:48:33,384 THINK PREDICTING IS ALWAYS HARD 1177 00:48:33,384 --> 00:48:35,220 TO SAY LIKE THIS VIRUS IS GOING 1178 00:48:35,220 --> 00:48:37,956 TO GO THIS WAY OR THAT WAY. 1179 00:48:37,956 --> 00:48:39,290 BUT I THINK WITH ENOUGH DATA WE 1180 00:48:39,290 --> 00:48:41,593 CAN AT LEAST LEARN CERTAIN 1181 00:48:41,593 --> 00:48:43,795 PATHWAYS THAT MIGHT BE LIKELY, 1182 00:48:43,795 --> 00:48:45,864 YOU KNOW, OR MORE LIKE BRACING 1183 00:48:45,864 --> 00:48:48,066 FOR IMPACT THAN HAVING TOOLS 1184 00:48:48,066 --> 00:48:50,235 THAT CAN -- OR THERAPEUTICS THAT 1185 00:48:50,235 --> 00:48:57,675 CAN HANDLE THOSE POSSIBLE 1186 00:48:57,675 --> 00:48:58,076 VARIANTS. 1187 00:48:58,076 --> 00:48:59,210 >> AND REGARDING THE VARIATION 1188 00:48:59,210 --> 00:49:00,144 IN AND OF ITSELF, WHAT DO YOU 1189 00:49:00,144 --> 00:49:04,415 THINK IS DRIVING A LOT OF THE 1190 00:49:04,415 --> 00:49:06,985 SEQUENCE VARIATION IN THE RBDs 1191 00:49:06,985 --> 00:49:10,922 THAT YOU'RE IDENTIFYING FROM 1192 00:49:10,922 --> 00:49:11,789 NATURE? 1193 00:49:11,789 --> 00:49:15,326 SO ARE RBDs UNDERGOING 1194 00:49:15,326 --> 00:49:16,494 SEQUENCE DIVERSIFICATION IN 1195 00:49:16,494 --> 00:49:20,465 RESPONSE TO -- ADAPTIVE IMMUNE 1196 00:49:20,465 --> 00:49:22,333 RESPONSE IN THE HOST AND/OR IS 1197 00:49:22,333 --> 00:49:24,168 IT RELATED TO SIMPLY RECEPTOR 1198 00:49:24,168 --> 00:49:25,069 USAGE? 1199 00:49:25,069 --> 00:49:27,338 >> YEAH, I THINK THAT'S -- A LOT 1200 00:49:27,338 --> 00:49:30,742 OF THE DIVERSITY WE SEE, 1201 00:49:30,742 --> 00:49:32,176 ESPECIALLY WITHIN SUBGENUS, 1202 00:49:32,176 --> 00:49:34,245 WITHIN THE SPECIFIC ANIMAL 1203 00:49:34,245 --> 00:49:37,849 POPULATION, A LOT OF HKU 5s 1204 00:49:37,849 --> 00:49:42,887 ARE FOUND IN BAT ROOSTS, SAME 1205 00:49:42,887 --> 00:49:44,255 WITH SARBECOVIRUS, OFTEN IN THE 1206 00:49:44,255 --> 00:49:45,189 SAME CAVE, THERE'S A LOT OF 1207 00:49:45,189 --> 00:49:46,824 PRESSURE ON THE POPULATION FROM 1208 00:49:46,824 --> 00:49:49,127 THE ADAPTIVE IMMUNE RESPONSE IN 1209 00:49:49,127 --> 00:49:51,296 THOSE ANIMALS, YOU KNOW, IN 1210 00:49:51,296 --> 00:49:54,599 ORDER FOR CIRCULATION TO STAY 1211 00:49:54,599 --> 00:49:55,900 PERSISTENT. 1212 00:49:55,900 --> 00:49:57,869 SO, YEAH, I THINK A LOT IS 1213 00:49:57,869 --> 00:50:00,705 DRIVEN BY ADAPTIVE RESPONSE BUT 1214 00:50:00,705 --> 00:50:02,907 THEN BECAUSE THERE'S SUCH A HIGH 1215 00:50:02,907 --> 00:50:04,509 ABUNDANCE OF VIRUSES IN SOME OF 1216 00:50:04,509 --> 00:50:07,011 THESE ANIMAL POPULATIONS I THINK 1217 00:50:07,011 --> 00:50:10,381 THERE IS PRESSURE THEN TO EXPAND 1218 00:50:10,381 --> 00:50:10,815 YOUR CELLULAR NICHE. 1219 00:50:10,815 --> 00:50:12,584 OF COURSE THIS IS ALL KIND OF, 1220 00:50:12,584 --> 00:50:13,785 YOU KNOW, JUST WHAT WE'VE BEEN 1221 00:50:13,785 --> 00:50:15,954 THINKING ABOUT FOR THE PAST 1222 00:50:15,954 --> 00:50:17,589 SEVERAL YEARS WITH ALL THIS 1223 00:50:17,589 --> 00:50:21,092 DATA, BUT THE FACT YOU DO SEE A 1224 00:50:21,092 --> 00:50:22,594 LOT OF THESE VIRUSES NOT 1225 00:50:22,594 --> 00:50:23,795 NECESSARILY CONVERGING ON THE 1226 00:50:23,795 --> 00:50:25,463 SAME RECEPTOR BUT ON THE SAME 1227 00:50:25,463 --> 00:50:26,664 TYPE OF RECEPTOR, THERE'S A LOT 1228 00:50:26,664 --> 00:50:30,068 OF REPEATED USE OF ACE 1 IN 1229 00:50:30,068 --> 00:50:31,936 THESE CORONAVIRUSES, AND DPP4, 1230 00:50:31,936 --> 00:50:34,339 AND APN, AND IT'S A HANDFUL OF 1231 00:50:34,339 --> 00:50:38,276 JUST A FEW MOLECULES THAT 1232 00:50:38,276 --> 00:50:38,776 VIRUSES FROM COMPLETELY 1233 00:50:38,776 --> 00:50:42,981 DIFFERENT BRANCHES OF THE TREES 1234 00:50:42,981 --> 00:50:43,915 CONVERGE ON AND LAND AT 1235 00:50:43,915 --> 00:50:45,917 DIFFERENT SPOTS, THAT GIVES US 1236 00:50:45,917 --> 00:50:46,918 CLUES ABOUT SOME UNDERLYING 1237 00:50:46,918 --> 00:50:47,151 BIOLOGY. 1238 00:50:47,151 --> 00:50:49,454 THESE VIRUSES HAVE TO USE NOT 1239 00:50:49,454 --> 00:50:52,624 JUST RECEPTOR BUT ALSO 1240 00:50:52,624 --> 00:50:53,257 PROTEASES, DIFFERENT ATTACHMENT 1241 00:50:53,257 --> 00:50:55,460 FACTORS, AND THOSE I THINK ARE 1242 00:50:55,460 --> 00:50:57,228 ALL CLUSTERED IN SPACE ON THE 1243 00:50:57,228 --> 00:50:59,097 CELL SURFACE SO THERE'S A LOT OF 1244 00:50:59,097 --> 00:51:00,932 PRESSURE TO, YOU KNOW, YOU HAVE 1245 00:51:00,932 --> 00:51:03,568 TO BE ABLE TO USE -- RETAINED 1246 00:51:03,568 --> 00:51:08,272 ABILITY TO USE ATTACHMENT 1247 00:51:08,272 --> 00:51:09,807 FACTORS, PROTEASES BUT IF YOU 1248 00:51:09,807 --> 00:51:11,342 WANT TO INFECT DIFFERENT CELL 1249 00:51:11,342 --> 00:51:13,611 TYPE YOU MIGHT NEED PRESSURE ON 1250 00:51:13,611 --> 00:51:15,713 THE RECEPTOR, THERE'S A COUPLE 1251 00:51:15,713 --> 00:51:17,915 DIFFERENT FORCES DRIVING HIGH 1252 00:51:17,915 --> 00:51:21,252 DIVERSITY IN THESE VIRUSES. 1253 00:51:21,252 --> 00:51:23,588 >> ENCOUNTERED A PAIRING WHERE 1254 00:51:23,588 --> 00:51:26,024 THE RBD SEQUENCE COULD NOT 1255 00:51:26,024 --> 00:51:26,958 COMPLETELY EXPLAIN ABILITY TO 1256 00:51:26,958 --> 00:51:29,727 INFECT CELL TYPE YOU'RE USING, 1257 00:51:29,727 --> 00:51:32,463 AND I THINK YOU DO SEE 1258 00:51:32,463 --> 00:51:33,097 INTERESTING DIFFERENCES BETWEEN 1259 00:51:33,097 --> 00:51:34,532 YOUR RBD CHIMERIC SPIKE AND YOUR 1260 00:51:34,532 --> 00:51:35,533 FULL LENGTH SPIKE. 1261 00:51:35,533 --> 00:51:38,970 SO WHAT ABOUT LIKE THE 1262 00:51:38,970 --> 00:51:39,837 N-TERMINAL DOMAIN OF SPIKE AND 1263 00:51:39,837 --> 00:51:40,071 -- 1264 00:51:40,071 --> 00:51:41,572 >> OH, YEAH. 1265 00:51:41,572 --> 00:51:43,107 THAT'S SOMETHING THAT, YEAH, OUR 1266 00:51:43,107 --> 00:51:44,175 CHIMERIC SPIKES GENERALLY WORK 1267 00:51:44,175 --> 00:51:46,144 BETTER IN OUR ASSAYS THAN THE 1268 00:51:46,144 --> 00:51:47,145 FULL LENGTH WILD TYPE. 1269 00:51:47,145 --> 00:51:50,014 AND I THINK A LOT OF THAT COMES 1270 00:51:50,014 --> 00:51:52,650 DOWN TO THE CHIMERIC BACKBONE WE 1271 00:51:52,650 --> 00:51:54,719 USE ON THESE REALLY OPTIMIZED 1272 00:51:54,719 --> 00:51:56,921 MERS SPIKES, WHERE WE KNOW MERS 1273 00:51:56,921 --> 00:51:59,190 WORKS REALLY WELL IN CULTURE. 1274 00:51:59,190 --> 00:52:03,461 A LOT OF THESE OTHER 1275 00:52:03,461 --> 00:52:03,995 GASTROINTESTINAL-BASED BAT 1276 00:52:03,995 --> 00:52:05,863 CORONAVIRUS SPIKES SEEM TO TAKE 1277 00:52:05,863 --> 00:52:07,065 A DIFFERENT CONFIRMATION WHERE 1278 00:52:07,065 --> 00:52:08,599 ALL THE RBDs ARE DOWN. 1279 00:52:08,599 --> 00:52:10,134 THAT'S NOT WHAT MERS DOES IN 1280 00:52:10,134 --> 00:52:12,236 CULTURE, AT LEAST IN OUR 1281 00:52:12,236 --> 00:52:12,470 SYSTEMS. 1282 00:52:12,470 --> 00:52:15,406 SO, I THINK THAT OUR CHIMERIC 1283 00:52:15,406 --> 00:52:17,141 SPIKES JUST ARE POISED BETTER 1284 00:52:17,141 --> 00:52:19,844 FOR ENTRY ASSAYS BECAUSE THEY 1285 00:52:19,844 --> 00:52:21,612 PRESENT RBDs BETTER, I THINK 1286 00:52:21,612 --> 00:52:23,381 THEY ALSO HAVE, YOU KNOW, WE 1287 00:52:23,381 --> 00:52:25,783 KNOW THAT MERS GROWS WELL ON THE 1288 00:52:25,783 --> 00:52:29,620 CELL LINES, SO IT CLEARLY HAS AN 1289 00:52:29,620 --> 00:52:31,789 OPTIMAL KIND OF INTERACTION AT 1290 00:52:31,789 --> 00:52:34,325 ALL THE OTHER DOMAINS INCLUDING 1291 00:52:34,325 --> 00:52:35,727 N-TERMINAL DOMAIN, SOME BAT 1292 00:52:35,727 --> 00:52:36,961 VIRUSES WE'RE NOT SURE IF THEY 1293 00:52:36,961 --> 00:52:38,596 ARE GOING TO BIND TO, YOU KNOW, 1294 00:52:38,596 --> 00:52:49,140 HUMAN AND HAMSTER GLYCANS WITH 1295 00:52:50,141 --> 00:52:53,811 THE SAME EFFICIENCY AS THE SARS 1296 00:52:53,811 --> 00:52:54,245 VIRUS. 1297 00:52:54,245 --> 00:52:56,647 OTHER FACTORS PLAY INTO ENTRY, 1298 00:52:56,647 --> 00:52:58,382 IF IT'S NOT CONFIRMATION OF THE 1299 00:52:58,382 --> 00:53:00,151 PROTEIN THEN IT'S SOME OF THE 1300 00:53:00,151 --> 00:53:01,152 OTHER DOMAINS. 1301 00:53:01,152 --> 00:53:02,987 >> IT'S ALSO POSSIBLE THAT BY 1302 00:53:02,987 --> 00:53:05,957 MAKING THESE KIND OF UNNATURAL 1303 00:53:05,957 --> 00:53:08,693 CHIMERAS THAT YOU COULD ACTUALLY 1304 00:53:08,693 --> 00:53:12,330 STUMBLE UPON A FULL LENGTH SPIKE 1305 00:53:12,330 --> 00:53:14,065 THAT HAS AN ARRANGEMENT THAT 1306 00:53:14,065 --> 00:53:18,336 JUST SO HAPPENS TO INFECT BETTER 1307 00:53:18,336 --> 00:53:20,838 THAN ANY OF THE OTHER NATURALLY 1308 00:53:20,838 --> 00:53:22,807 EXISTING SPIKES, SO LIKE BY 1309 00:53:22,807 --> 00:53:25,777 COMBINING THE RDB WITH A GIVEN 1310 00:53:25,777 --> 00:53:31,682 REGION OUTSIDE OF THE RBD, YOU 1311 00:53:31,682 --> 00:53:32,350 KNOW. 1312 00:53:32,350 --> 00:53:33,651 SO THIS PERSON HAS ASKED A 1313 00:53:33,651 --> 00:53:34,819 REALLY INTERESTING QUESTION. 1314 00:53:34,819 --> 00:53:39,824 I WAS THINKING ABOUT IT MYSELF. 1315 00:53:39,824 --> 00:53:40,625 SO, FOR THESE MERBECOVIRUSES 1316 00:53:40,625 --> 00:53:43,861 THAT SEEM TO HAVE DUAL RECEPTOR 1317 00:53:43,861 --> 00:53:45,730 ACTIVITY WHAT CAME FIRST? 1318 00:53:45,730 --> 00:53:48,566 AND FOR THE MERBECOVIRUSES IN 1319 00:53:48,566 --> 00:53:49,534 GENERAL DO YOU THINK ACE-2 WOULD 1320 00:53:49,534 --> 00:53:55,306 BE MORE OF THE ANCESTRAL 1321 00:53:55,306 --> 00:53:58,843 RECEPTOR AND DPP4 WOULD HAVE 1322 00:53:58,843 --> 00:54:03,447 AROSE AFTER THAT? 1323 00:54:03,447 --> 00:54:04,982 >> IT'S HARD TO PINPOINT BECAUSE 1324 00:54:04,982 --> 00:54:07,518 IT'S SO VARIABLE IN THESE 1325 00:54:07,518 --> 00:54:07,852 VIRUSES. 1326 00:54:07,852 --> 00:54:12,190 BUT, YEAH, IF YOU TALK TO TYLER 1327 00:54:12,190 --> 00:54:15,393 STARR, THEIR DATA SUGGESTS THAT 1328 00:54:15,393 --> 00:54:19,964 ACE-2 IS AN ANCESTRAL BINDING 1329 00:54:19,964 --> 00:54:21,332 PROPERTY FOR THE SARBECOVIRUSES. 1330 00:54:21,332 --> 00:54:22,834 NEED TO DO SIMILAR TYPE OF 1331 00:54:22,834 --> 00:54:25,970 APPROACH TO DETERMINE THAT FOR 1332 00:54:25,970 --> 00:54:27,572 THE MERBECOVIRUSES. 1333 00:54:27,572 --> 00:54:29,607 BUT, YEAH, GIVEN SO MANY OF 1334 00:54:29,607 --> 00:54:32,577 THESE VIRUSES USE ACE-2 OR CAN 1335 00:54:32,577 --> 00:54:33,911 BE SWAYED TO USE IT SEEMS LIKE 1336 00:54:33,911 --> 00:54:36,948 THAT MIGHT BE A DEFAULT AND THEN 1337 00:54:36,948 --> 00:54:39,083 THERE'S DEVIATIONS IN PRESSURE 1338 00:54:39,083 --> 00:54:41,018 FROM BEYOND THAT TO DIVERSIFY. 1339 00:54:41,018 --> 00:54:45,256 BUT AGAIN WE'RE NOT 100% SURE, 1340 00:54:45,256 --> 00:54:49,660 MAYBE DBB 4 WAS THE ANCESTRAL 1341 00:54:49,660 --> 00:54:51,295 ONE BEING SWAPPED OUT BY THE 1342 00:54:51,295 --> 00:54:58,736 NEWER AIRS 2 VIRUSES BUT I DON'T 1343 00:54:58,736 --> 00:55:00,838 THINK PHYLOGENETIC DATA TELLS US 1344 00:55:00,838 --> 00:55:01,172 THAT. 1345 00:55:01,172 --> 00:55:02,306 YOU'RE LIMITED TO THAT REGION IF 1346 00:55:02,306 --> 00:55:05,877 YOU WANT TO STUDY HOW THAT PART 1347 00:55:05,877 --> 00:55:09,480 OF THE GENE EVOLVED. 1348 00:55:09,480 --> 00:55:11,883 >> ANOTHER QUESTION ASKS, WHY 1349 00:55:11,883 --> 00:55:13,851 DPP4 AND ACE-2, ARE THERE 1350 00:55:13,851 --> 00:55:14,619 STRUCTURAL SIMILARITIES BETWEEN 1351 00:55:14,619 --> 00:55:18,756 THE TWO, FOR EXAMPLE, WHAT WOULD 1352 00:55:18,756 --> 00:55:23,494 BE THE RATIONALE FOR A VIRUS 1353 00:55:23,494 --> 00:55:24,662 EVOLVING, ABILITY TO BIND ONE 1354 00:55:24,662 --> 00:55:25,796 AND THEN BOTH? 1355 00:55:25,796 --> 00:55:27,465 >> WELL THEY ARE NOT BINDING 1356 00:55:27,465 --> 00:55:27,665 BOTH. 1357 00:55:27,665 --> 00:55:30,401 THEY ARE BINDING ONE OR THE 1358 00:55:30,401 --> 00:55:30,601 OTHER. 1359 00:55:30,601 --> 00:55:32,803 SO, YEAH, YOU KNOW, KIND OF GETS 1360 00:55:32,803 --> 00:55:37,275 AT SOME WORK, REALLY COOL WORK 1361 00:55:37,275 --> 00:55:42,546 FROM TOM GALLAGHER'S LAB LOYAL. 1362 00:55:42,546 --> 00:55:45,483 THE SPIKE BINDS TO RBD, PROTEASE 1363 00:55:45,483 --> 00:55:47,785 PROCESSES THE SPIKE, AND THEN 1364 00:55:47,785 --> 00:55:49,220 THAT RELEASES THE FUSION 1365 00:55:49,220 --> 00:55:54,325 PEPTIDE, ALLOWS FUSION TO OCCUR 1366 00:55:54,325 --> 00:55:55,760 AT CELL SURFACE. 1367 00:55:55,760 --> 00:55:57,862 TOM SHOWS DPP4 IS STRUCTURALLY 1368 00:55:57,862 --> 00:55:59,597 COUPLED TO THE PROTEASE NEEDED 1369 00:55:59,597 --> 00:56:08,906 FOR THAT EVENT THROUGH A BRIDGE 1370 00:56:08,906 --> 00:56:09,607 MOLECULE, TETRA SPANNING 1371 00:56:09,607 --> 00:56:10,841 MOLECULAR RAFT IN THE MEMBRANE. 1372 00:56:10,841 --> 00:56:12,043 THEY NEED TO BE IN CLOSE 1373 00:56:12,043 --> 00:56:15,579 PROTECTION I FOR -- 1374 00:56:15,579 --> 00:56:18,115 PROXIMITIESTY FOR ENTRY. 1375 00:56:18,115 --> 00:56:20,518 YOU CAN HAVE HIGH EXPRESSION IN 1376 00:56:20,518 --> 00:56:21,385 THE CELL BECAUSE BECAUSE THEY 1377 00:56:21,385 --> 00:56:23,020 ARE NOT LINKED THERE'S NO ENTRY. 1378 00:56:23,020 --> 00:56:24,221 THAT'S SOMETHING WE'RE ONLY 1379 00:56:24,221 --> 00:56:25,556 REALLY JUST STARTING TO SCRATCH 1380 00:56:25,556 --> 00:56:28,025 THE SURFACE ON WITH A LOT OF 1381 00:56:28,025 --> 00:56:29,827 THESE VIRUSES, BUT WHAT I 1382 00:56:29,827 --> 00:56:31,996 SUSPECT BECAUSE ALL THESE 1383 00:56:31,996 --> 00:56:32,897 CORONAVIRUSES USE THE SAME 1384 00:56:32,897 --> 00:56:34,432 PROTEASE OR SAME FAMILY OF 1385 00:56:34,432 --> 00:56:36,934 PROTEASES, I THINK THOSE 1386 00:56:36,934 --> 00:56:39,003 PROTEASES ARE NATURALLY COUPLED 1387 00:56:39,003 --> 00:56:41,973 TO DPP4 AND ACE-2, POTENTIALLY 1388 00:56:41,973 --> 00:56:43,040 SOME OTHER CORONAVIRUS 1389 00:56:43,040 --> 00:56:43,307 RECEPTORS. 1390 00:56:43,307 --> 00:56:46,577 >> I THINK THAT'S A COMPELLING 1391 00:56:46,577 --> 00:56:46,877 EXPLANATION. 1392 00:56:46,877 --> 00:56:47,778 >> SO, YEAH, THAT PUTS PRESSURE 1393 00:56:47,778 --> 00:56:49,313 THEN ON THAT VIRUS SO IF IT 1394 00:56:49,313 --> 00:56:52,917 EVOLVES TO USE A DIFFERENT 1395 00:56:52,917 --> 00:56:55,419 RECEPTOR CAN IT USE A TOTALLY 1396 00:56:55,419 --> 00:56:56,620 DIFFERENT RECEPTOR THAT TAKES 1397 00:56:56,620 --> 00:56:57,955 AWAY NEIGHBORING PROTEASE 1398 00:56:57,955 --> 00:56:58,956 BECAUSE THAT WOULD REQUIRE 1399 00:56:58,956 --> 00:57:01,892 EVOLUTION TO OCCUR AT BOTH 1400 00:57:01,892 --> 00:57:03,761 PROTEASE SITE AND RBD KIND OF 1401 00:57:03,761 --> 00:57:05,162 THEY SAME TIME SO IT'S EASIER 1402 00:57:05,162 --> 00:57:08,232 FOR A LITTLE POINT MUTATION AND 1403 00:57:08,232 --> 00:57:10,768 DELETION TO RESURFACE PROTEIN TO 1404 00:57:10,768 --> 00:57:12,837 STICK TO A NEIGHBORING MOLECULE 1405 00:57:12,837 --> 00:57:15,339 THAT STILL MAINTAINS THE REST OF 1406 00:57:15,339 --> 00:57:16,874 THE ESSENTIAL INTERACTIONS. 1407 00:57:16,874 --> 00:57:19,410 >> THIS MAKES ME THINK OF THE 1408 00:57:19,410 --> 00:57:22,847 RECENT PAPERS SHOWING HUMAN 1409 00:57:22,847 --> 00:57:26,183 SEASONAL CORONAVIRUS CAN USE 1410 00:57:26,183 --> 00:57:27,585 TMPRSS2 AS A RECEPTOR. 1411 00:57:27,585 --> 00:57:27,918 >> EXACTLY. 1412 00:57:27,918 --> 00:57:30,021 ANOTHER EXAMPLE OF A CORONAVIRUS 1413 00:57:30,021 --> 00:57:32,189 USING ONE OF FOUR OR FIVE 1414 00:57:32,189 --> 00:57:34,191 PROTEINS THAT SUSPECT IN SOME 1415 00:57:34,191 --> 00:57:36,594 WAY ARE PROBABLY COUPLED IN THE 1416 00:57:36,594 --> 00:57:40,331 CELL SURFACE. 1417 00:57:40,331 --> 00:57:41,966 AND VARYING DEGREES, MAYBE CELL 1418 00:57:41,966 --> 00:57:44,702 TYPES, YEAH, SOMETHING LIKE 1419 00:57:44,702 --> 00:57:45,002 THAT. 1420 00:57:45,002 --> 00:57:46,937 >> RELATING TO THESE QUESTIONS 1421 00:57:46,937 --> 00:57:50,474 THERE'S ONE ABOUT, YOU KNOW, IS 1422 00:57:50,474 --> 00:57:53,110 DPP4 UNDER POSITIVE SELECTION IN 1423 00:57:53,110 --> 00:57:55,646 MAMMALS AS THERE HAVE BEEN SOME 1424 00:57:55,646 --> 00:57:58,616 STUDIES SHOWING POSITIVE 1425 00:57:58,616 --> 00:57:59,183 SELECTION IN ACE-2? 1426 00:57:59,183 --> 00:58:01,318 >> YEAH, THERE IS A LITTLE BIT 1427 00:58:01,318 --> 00:58:03,320 OF -- THERE ARE SOME SIGNS OF 1428 00:58:03,320 --> 00:58:05,256 POSITIVE SELECTION BUT A LOT OF 1429 00:58:05,256 --> 00:58:07,558 THEM ARE AT SURFACES THAT 1430 00:58:07,558 --> 00:58:08,759 AREN'T -- WELL, THAT'S THE 1431 00:58:08,759 --> 00:58:08,959 THING. 1432 00:58:08,959 --> 00:58:10,461 WE DON'T KNOW ALL THE SURFACES 1433 00:58:10,461 --> 00:58:11,829 THAT WOULD INTERACT WITH THE 1434 00:58:11,829 --> 00:58:14,131 VIRUS BUT THEY ARE NOT AT A LOT 1435 00:58:14,131 --> 00:58:16,567 OF SURFACES WE KNOW WOULD 1436 00:58:16,567 --> 00:58:19,070 INTERACT WITH THOSE MOLECULES. 1437 00:58:19,070 --> 00:58:21,806 THEY ALSO DPP4 HAS ITS OWN 1438 00:58:21,806 --> 00:58:23,140 BIOLOGICAL FUNCTION IN 1439 00:58:23,140 --> 00:58:23,841 CHOLESTEROL PROCESSING, AND 1440 00:58:23,841 --> 00:58:25,776 THERE'S VARIATION IN SOME OF 1441 00:58:25,776 --> 00:58:26,444 THOSE POINTS. 1442 00:58:26,444 --> 00:58:28,979 WHICH IS KIND OF AN INTERESTING 1443 00:58:28,979 --> 00:58:29,313 THING. 1444 00:58:29,313 --> 00:58:31,248 SO, IT'S NOT ENTIRELY CLEAR IF 1445 00:58:31,248 --> 00:58:33,651 THERE'S A LOT OF -- I THINK 1446 00:58:33,651 --> 00:58:36,921 MAYBE THAT PART OF THAT PROBLEM 1447 00:58:36,921 --> 00:58:41,659 MIGHT BE WE DON'T KNOW THE EXACT 1448 00:58:41,659 --> 00:58:46,130 SPECIES THAT MERBECOVIRUSES 1449 00:58:46,130 --> 00:58:47,765 CIRCULATE IN. 1450 00:58:47,765 --> 00:58:49,733 WE KNOW SOME BAT SPECIES BUT WE 1451 00:58:49,733 --> 00:58:51,502 DON'T THINK IT CAUSES A LOT OF 1452 00:58:51,502 --> 00:58:53,771 PATHOLOGY IN THOSE ANIMALS WHICH 1453 00:58:53,771 --> 00:58:55,139 REDUCES OUR ABILITY TO SEE 1454 00:58:55,139 --> 00:58:56,640 PROBABLY A LOT OF STRONG 1455 00:58:56,640 --> 00:58:56,974 SELECTION. 1456 00:58:56,974 --> 00:58:57,942 >> THAT BRINGS UP ANOTHER 1457 00:58:57,942 --> 00:58:58,375 QUESTION. 1458 00:58:58,375 --> 00:59:01,779 WHAT ABOUT THE AGE OF THESE 1459 00:59:01,779 --> 00:59:02,012 VIRUSES? 1460 00:59:02,012 --> 00:59:03,547 FOR EXAMPLE, IN BATS, IF WE'RE 1461 00:59:03,547 --> 00:59:05,749 CONSIDERING THEM THE CLOSEST 1462 00:59:05,749 --> 00:59:06,717 THING TO A RESERVOIR HOW LONG DO 1463 00:59:06,717 --> 00:59:09,887 YOU THINK THEY HAVE BEEN 1464 00:59:09,887 --> 00:59:11,555 HARBORING THESE VIRUSES? 1465 00:59:11,555 --> 00:59:16,594 >> I'D HAVE TO GO BACK AND LOOK 1466 00:59:16,594 --> 00:59:18,863 AT SOME OLDER MOLECULAR CLOCKS, 1467 00:59:18,863 --> 00:59:22,700 WORKING WITH A GROUP NOW USING 1468 00:59:22,700 --> 00:59:23,801 THE MINK VIRUSES, SPILLOVER FROM 1469 00:59:23,801 --> 00:59:27,071 BATS OR MINK LIKELY OCCURRED IN 1470 00:59:27,071 --> 00:59:27,938 THE '90s. 1471 00:59:27,938 --> 00:59:31,442 SO, WE KNOW THAT FOR MERS 1472 00:59:31,442 --> 00:59:34,845 CORONAVIRUS THAT'S BEEN 1473 00:59:34,845 --> 00:59:36,914 RETROACTIVELY FOUND IN POSSIBLY 1474 00:59:36,914 --> 00:59:38,349 SERUM SAMPLES, SERUM RESPONSE IN 1475 00:59:38,349 --> 00:59:39,850 SAMPLES FROM THE '80s. 1476 00:59:39,850 --> 00:59:42,186 SO HUMAN SAMPLES FROM THE 1477 00:59:42,186 --> 00:59:42,486 '80s. 1478 00:59:42,486 --> 00:59:44,588 SO THESE VIRUSES HAVE BEEN 1479 00:59:44,588 --> 00:59:45,923 CIRCULATING FOR A WHILE, 1480 00:59:45,923 --> 00:59:48,926 DECADES, BUT I DON'T KNOW ABOUT 1481 00:59:48,926 --> 00:59:50,694 THE EXACT, YOU KNOW, HOW FAR IT 1482 00:59:50,694 --> 00:59:51,795 GOES BACK. 1483 00:59:51,795 --> 00:59:52,897 BUT LIKELY QUITE A WHILE. 1484 00:59:52,897 --> 00:59:55,065 >> I MEAN THE WHOLE QUESTION IF 1485 00:59:55,065 --> 00:59:57,268 THEY CAUSE DISEASE IN BATS 1486 00:59:57,268 --> 00:59:59,670 BRINGS UP THIS IDEA OF HAVE THEY 1487 00:59:59,670 --> 01:00:00,971 COEXISTED WITH BATS. 1488 01:00:00,971 --> 01:00:02,606 >> FOR A LONG TIME, EXACTLY. 1489 01:00:02,606 --> 01:00:04,175 >> FOR A LONG TIME, YEAH. 1490 01:00:04,175 --> 01:00:06,911 >> I'D HAVE TO LOOK BACK AT SOME 1491 01:00:06,911 --> 01:00:10,848 OF THOSE CLOCKS TO SEE IF PEOPLE 1492 01:00:10,848 --> 01:00:12,917 PINPOINTED EXACT SPILLOVER OR 1493 01:00:12,917 --> 01:00:14,585 MOST RECENT COMMON ANCESTOR 1494 01:00:14,585 --> 01:00:14,818 STUDIES. 1495 01:00:14,818 --> 01:00:16,220 >> THAT WAS GREAT. 1496 01:00:16,220 --> 01:00:18,289 THANKS FOR FIELDING THOSE 1497 01:00:18,289 --> 01:00:18,656 QUESTIONS. 1498 01:00:18,656 --> 01:00:21,458 AND AGAIN FOR A REALLY EXCELLENT 1499 01:00:21,458 --> 01:00:21,659 TALK. 1500 01:00:21,659 --> 01:00:22,860 EVERYONE REALLY ENJOYED THAT. 1501 01:00:22,860 --> 01:00:26,363 WE'VE COME UP ON THE HOUR. 1502 01:00:26,363 --> 01:00:28,332 SO WE AS A COMMITTEE WOULD LIKE 1503 01:00:28,332 --> 01:00:33,304 TO THANK YOU FOR PARTICIPATING 1504 01:00:33,304 --> 01:00:34,171 IN OUR SEMINAR SERIES. 1505 01:00:34,171 --> 01:00:35,472 >> THANKS FOR HAVING ME. 1506 01:00:35,472 --> 01:00:39,276 >> THANKS A LOT. 1507 01:00:39,276 --> 01:00:42,046 [END OF PROGRAM] 1508 01:00:42,046 --> 01:00:52,089