>>WELCOME TO A COMBINED WEDNESDAY AFTERNOON LECTURE SERIES AND DEMYSTIFYING MEDICINE LECTURE TODAY. THIS IS THE 12TH DEMYSTIFYING MEDICINE TOPIC OF THE YEAR, AND WE'RE IN OUR 21ST YEAR. SO THE GOAL OF BOTH OF THESE ACTIVITIES, THE WALS AND THE DEMYSTIFYING MEDICINE, IS TO BRIDGE AND EXCITE YOU WITH DEVELOPMENTS IN BIOLOGY, AND TODAY, THE TOPIC IS ENGINEERING, EXCITING BRIDGING THIS WITH MEDICINE.
THIS IS THE LOGO, THE BROOKLYN BRIDGE. WE AS ALWAYS ARE LIKE THE INDIVIDUALS ON THE CATWALK, AND TODAY, WE'RE GOING TO HEAR FROM A LEADING BIOENGINEER, AND WE'RE INTERESTED IN ITS RELATIONSHIP OF HER WORK TO MEDICINE, AND THAT'S THE TOPIC. THIS IS A COURSE IN BRIDGE BUILDING. NEXT SLIDE. ANOTHER WAY OF EXPRESSING THE SAME IDEA WAS BY PROFESSOR KOLLATH, A EUROPEAN BIOCHEMIST IN THE EARLY 20TH CENTURY WHO SAID, TRANSLATED: MUCH IS KNOWN, BUT UNFORTUNATELY IN DIFFERENT HEADS.
SO ONE OF THE PURPOSES OF DEMYSTIFYING MEDICINE IS TO EXCHANGE INFORMATION AND BRING TOGETHER KNOWLEDGE INTO AREAS THAT OTHERWISE WE WOULDN'T KNOW. TODAY WE ARE FORTUNATE TO HAVE WITH US SANGEETA BHATIA, WHO IS TREUL LIE AN IS A EXTRAORDINARY BRIDGE BUILDER. HER RESEARCH GOAL HAS BEEN TO ENGINEER MICRO AND NANOTECHNOLOGIES TO ADDRESS COMPLEX CHALLENGES IN HUMAN HEALTH INCLUDING CANCER, LIVER DISEASE, AND ACQUIRED INFECTIONS. THE NEXT SLIDE. SOMETHING ABOUT SANGEETA, SHE IS A PERSON OF EXTRAORDINARY ACCOMPLISHMENT.
I THINK OF HER SOMETIMES AS A COLLECTOR. FOR EXAMPLE, SHE HAS COLLECTED DEGREES LISTED ON THE TOP OF THE SLIDE. AND HAS A PH.D. IN BIOMEDICAL
ENGINEERING FROM THE HEALTH SCIENCE TECHNOLOGY PROGRAM. TENURED AT UCSD, THEN RETURNED TO MIT, WHERE SHE IS THE WILSON PROFESSOR OF HEALTH SCIENCE AND TECHNOLOGY, THE DIRECTOR OF THE MARBLE CENTER FOR CANCER STUDIES WITH NANOMEDICINE. SHE'S A HOWARD HUGHES INVESTIGATOR, AND A MEMBER OF THE BROAD AND THE WYSS INSTITUTES. SANGEETA HAS RECEIVED EXTRAORDINARY RECOGNITION. I'LL JUST MENTION A FEW.
SHE RECEIVED THE LEMELSON-MIT AWARD REFERRED TO AS THE OSCAR FOR INVENTORS, AND THE HEINZ AWARD FOR INVENTIONS IN ADVOCACY. SANGEETA IS A POWERFUL ADVOCATE FOR WOMEN, FOR DIVERSITY AND FOR HIGH STANDARDS IN ALL OF OUR ACTIVITIES. EXTRAORDINARILY ENOUGH, SHE'S THE ONLY PERSON I KNOW WHO'S BEEN ELECTED TO ALL FIVE NATIONAL ACADEMIES: OF SCIENCE, ENGINEERING, MEDICINE, ARTS AND SCIENCE, AND INVENTORS. IN ADDITION, SHE HAS CRITICAL BOARD MEMBERSHIPS, ADVISORY COMMITTEES AND CONSULTING, AND WE ARE REALLY MOST PLEASED AND DELIGHTED TO HAVE YOU WITH US TODAY, SANGEETA, AND SHE WILL SPEAK TO US ABOUT TINY TECHNOLOGIES AND MEDICINE: FROM HEPATIC TISSUE ENGINEERING TO CANCER NANOTECHNOLOGY.
SANGEETA? >> THANK YOU, WIN. I JUST WANTED TO THANK WIN AND THE ORGANIZERS FOR THIS DOUBLEHEADER TODAY, DOING BOTH WALS AND DEMYSTIFYING MEDICINE. IT'S A REAL TREAT TO SHARE MY PERSPECTIVES AND TO SEE YOU ALL VIRTUALLY, AND I'M LOOKING FORWARD TO THE DAY WHEN WE CAN ALL MEET IN PERSON. BUT TECHNOLOGY HAS SOME ADVANTAGES, WHICH IS THAT WE GET TO REACH A WIDER AUDIENCE. SO THE STORY I'LL BE TELLING YOU TODAY IS, AS WIN DESCRIBED, A STORY ABOUT USING ENGINEERING TOOLS TO TACKLE PROBLEMS IN BIOMEDICAL RESEARCH, AS WELL AS NEW POTENTIAL INVENTIONS TO ADDRESS UNMET MEDICAL NEEDS. AND I'LL BE TELLING YOU ABOUT OUR WORK IN LIVER TISSUE ENGINEERING AND CANCER NANOTECHNOLOGY.
THESE ARE MY REQUIRED DISCLOSURES. I DO WANT TO HIGHLIGHT THAT I'LL BE SHOWING DATA FROM TWO STARTUPS: GLYMPSE AND SAT LIE BIOTHAT RELATE TO MY WORK AND I AM AN EQUITY HOLDER IN THOSE ESTABLISHMENTS. OKAY. SO MY KIND OF PLAY SAND BOX HAS BEEN THE WORLD OF TINY TECHNOLOGIES.
AND JUST TO SORT OF GET US ALL ON THE SAME PAGE ABOUT WHAT THAT MEANS, WHAT I'M REFERRING TO ARE THE TECHNOLOGIES OF MICRO AND NANOTECHNOLOGY THAT REALLY GREW OUT OF THE SEMICONDUCTOR INDUSTRY. SO HERE YOU CAN SEE ONE MARBLE THAT THIS HAS GIVEN US, AND THAT IS THAT ONE TRANSISTOR USED TO BE THE SIZE THAT YOU SEE ON THE LEFT. AND WE CAN NOW FIT A BILLION OF THOSE ON THE SAME FOOTPRINT. AND THAT'S THROUGH AGGRESSIVE MINIATURIZATION OF SEMICONDUCTOR TECHNOLOGY.
THAT HAS, OF COURSE, MINIATURIZED COMPUTATION AND CHANGE TO ALL OF OUR LIVES, REALLY. SO IF WE LOOK BACK AND THINK ABOUT HOW THAT HAPPENED, YOU KNOW, BEGINNING IN THE 1960s UP TO THE 2000s, THE CIRCUITS THAT ARE WRITTEN ON SILICON SEMICONDUCTOR CHIPS WITH LIGHT HAVE GOTTEN SMALLER AND SMALLER. AND STARTING IN THE YEAR 2000, WE STARTED TO BE ABLE TO MAKE FEATURES ON THESE CHIPS THAT WERE SMALLER THAN 100 NANOMETERS.
AND ACTUALLY IN 2020, IN THE LATEST SMARTPHONE, THEY'RE SMALLER THAN 5 NANOMETERS. SO WE CAN DRAW INCREDIBLY TINY FEATURES IN WHAT'S CALLED TOP-DOWN FABRICATION. START WITH A BIG THING AND YOU WRITE SMALL THINGS ON IT. NOW THIS ADVANCE HAS BEEN COUPLED BY ANOTHER ADVANCE ON THE RIGHT HERE, WHICH COMES FROM THE WORLD OF -- REALLY FROM CHEMISTRY AND MACROMOLECULAR CHEMISTRY. AND HERE, THERE'S A GROUP OF INVESTIGATORS THAT HAVE BEEN ASSEMBLING MOLECULES AND COAXING THEM INTO MAKING NANOMATERIALS.
YOU SEE A VARIETY OF THEM ON THE SIDE HERE, INCLUDING, FOR EXAMPLE, LIPID NANOMATERIALS WHICH ARE, OF COURSE, HOW COVID MRNA VACCINES ARE DELIVERED, AS WELL AS SOME OTHER VERY FAMOUS ONES, FOR EXAMPLE, BUT KEY BALLS. BUCKY BALLS. SO WE HAVE TWO DIFFERENT SETS OF TECHNOLOGY THAT HAVE CONVERGED OND A SCALE, WE THINK OF HUMAN HARRAH'S ABOUT 100 MICRONS, AND. AS INVENTORS INTERESTED IN HUMAN HEALTH, IF YOU KIND OF SPLAY THESE TECHNIQUES ACROSS A RULER, THIS INDUSTRY HAS GIVEN US TOOLS THAT ARROW US TO MA MANIPULATE EVERYTHING FROM THE LINK SCALE OF A RECEPTOR UP TO GROUPS OF CELLS WHICH REALLY FORM FUNCTIONAL UNITS IN OUR TISSUES AROUND SORT OF HUNDREDS OF MICRONS. SO WHAT I'D LIKE TO TELL YOU TODAY IS ABOUT TWO TISSUE MICRO ENVIRONMENTS, THE LIVER MICROENVIRONMENT AND TUMOR MICRO ENVIRONMENTS. AND HOW WE CAN CREATE TOOLS THAT ALLOW US TO DISSECT THESE MICROENVIRONMENT OR ASSEMBLE THEM FOR THERAPEUTIC PURPOSES.
I'LL TELL YOU TWO STORIES ABOUT THE LIVER, IN HONOR OF WIN, AND ONE STORY ABOUT TEU TUMORS. SO STARTING WITH HEPATIC MICRO ENVIRONMENTS, THEN, JUST A LITTLE ORIENTATION ON THE LIVER. THIS IS AN IMAGE FROM A FAMOUS ANATOMIST OF THE LIVER. YOU CAN SEE IT HAS THIS GORGEOUS MICRO ARCHITECTURE WITH MANY INTERACTING CELL TYPES, AND THIS GIVES RISE TO SOME 500 FUNCTIONS. THE THE LIVER IS VITAL FOR LIFE. PABLO NARUTA DESCRIBED IT AS THE MODEST ORGANIZED UNDERGROUND WORKER OF OUR BODY.
IT'S UNDERAPPRECIATED. IT CAN DO REMARKABLE THINGS. IT'S UNFORTUNATELY -- ITS DYSFUNCTION TOUCHES 500 MILLION PATIENTS WORLDWIDE, AND IT HAS REMARKABLE CAPABILITIES WHERE IT CAN REGENERATE UNDER CERTAIN CIRCUMSTANCES. SO IT'S JUST A FASCINATING ORGAN. I'VE STUDIED IT MOST OF MY CAREER AND I KNOW WIN HAS STUDIED IT MUCH LONGER THAN ME.
SO YOU THINK ABOUT WHAT CAN YOU STUDY ABOUT THIS ARCHITECTURE OF THIS ORGAN WITH THESE TOOLS. SO I'M GOING TO START WITH AN EXAMPLE OF WHAT ONE CAN STUDY BY CREATING AN ARTIFICIAL HUMAN MICROENVIRONMENT IN TWO DIMENSIONS. SO ON A FLAT SURFACE. AND HERE WHAT WE DO IS WE PATTERN SURFACES WITH LIGHT FROM THE SEMICONDUCTOR TOOL INDUSTRY, AND WE PATTERN BIOMOLECULES ON THOSE SURFACES THAT WILL CONFER THE ADHESION OF CELLS.
SO HERE YOU CAN SEE WORK FROM MY COLLEAGUES WHERE YOU CAN PATTERN A SINGLE CELL ON AN ISLAND OF FIBRANECTIN OR A BOW TIE OF TWO CELLS OR AN ASYMMETRIC MULTICELLULAR ISLAND. SO THESE TOOLS ARE VERY GENERIC, WE CAN ESSENTIALLY PRECISELY PLACE SELLS KRELS ON CELLS ON A SURFACE AND STUDY THE ARCHITECTURE OF THAT COMMUNITY. JUST TO GIVE YOU A SENSE OF HOW GENERIC THIS TOOL IS, THIS IS AN IMAGE OF A SURFACE THAT HAD BEEN PATTERNED WITH COLLAGEN TYPE 1 BY A FORMER POSTDOC OF MINE. THIS IS ACTUALLY PART OF A TRAVELING ART EXHIBIT AND WIN HAS A COPY OF THIS ON HIS WALL ACTUALLY. THESE ARE RAD HEPATOCYTES PATTERNED IN COLLABORATION WITH AN ARTIST.
IF YOU ZOOM IN ON THESE, YOU CAN SEE THESE STRUCTURES WHICH ARE SPECIFIED BY LIGHT-BASED PA PATTERNING OF COLLAGEN ARE INCREDIBLY PRECISE AND REALLY WHAT'S COMPOSED OF THEM IS RAD HEPATOCYTES SPREAD ON THAT SURFACE. SO THESE ARE VERY GENERIC TOOLS. SO I'D LIKE TO TELL YOU NOW WHAT ONE COULD STUDY IN A TWO-DIMENSIONAL SYSTEM LIKE THIS. IT MAY SURPRISE YOU THAT THIS VIGNETTE IS GOING TO BE ACTUALLY ABOUT A HUMAN PATHOGEN THAT WE THINK OF AS A DISEASE OF THE BLOOD. THAT'S PLASMODIUM VIVAX. AS I'LL SHOW YOU IN A MOMENT, THIS ORGANISM HAS AN OBLIGATE STAGE OF ITS LIFE CYCLE IN THE LIVER, WHICH UNTIL VERY RECENTLY, WE HAVE NOT KNOWN MUCH ABOUT.
SO PLASMODIUM VIVAX REALLY AFFECTS MANY PEOPLE GLOBALLY, AND UNLIKE ITS COUSIN, IT TURNS OUT TO BE A RELAPSING FORM OF MALARIA, AND BECAUSE OF THAT, IT'S QUITE DIFFICULT TO ERADICATE. SO LET ME SHOW YOU A LITTLE BIT MORE ABOUT ITS LIFE CYCLE. AND WHY THE LIVER PART OF IT IS SO INTERESTING. SO HERE IS A SPORE ZOITE COMING FROM AN INFECTED MOSQUITO. THAT WILL TRAVEL TO THE LIVER, WHERE IT INFECTS HEPATOCYTES, UNIQUELY. IT WILL MULTIPLY OVER SEVEN TO 10 DAYS.
AND THEN BURST OUT OF THE LIVER, WHERE IT WILL INFECT YOUNG RED BLOOD CELLS, RETICULOCYTES, AND THEN START THE PATTERN OF CYCLIC FEVER THAT WE ASSOCIATE WITH MALARIA. NOW WHAT'S INTERESTING AND SPECIAL ABOUT THE LIVER STAGE OF THIS ORGANISM IS THAT THIS IS A BOTTLENECK IN THE LIFE CYCLE, IF YOU WILL. SO WHEN YOU START OUT WITH RELATIVELY FEW SPORE ZOITES AND THE ORGANISM MULTIPLIES. SO FROM A THERAPEUTIC PERSPECTIVE, IF YOU COULD TARGET IT IN THE LIVER, YOU WOULD PREVENT SYMPTOMS, YOU WOULD PREVENT TRANSMISSION, WHICH WILL HAPPEN LATER IN THE BLOOD STAGE, AND YOU WOULD PREVENT THIS AMPLIFICATION OF BIOMASS OF THE ORGANISM. SO THERE'S BEEN A LOT OF INTEREST IN TARGETING AT THIS STAGE, AND THERE'S ONLY ONE DRUG SO FAR THAT'S ABLE TO DO IT, AND THAT'S A VERY OLD DRUG CALLED PRIMOQUINN. THE REASON THIS CAN RELAPSE EVEN AFTER IT'S CLEARED IS BECAUSE OF THIS GUY HERE.
THIS IS CALLED THE HYPNOZOITE FOR HYPNOTIZE. IT CAN STAY IN THE LIVER AS A DORMANT -- IT STARTS TO MULTIPLY AND IT CAN START THE WHOLE LIFE CYCLE AGAIN. SO THERE HAVE BEEN MANY GAPS IN OUR UNDERSTANDING OF THIS LITTLE ORGANISM. WE DON'T KNOW ITS INCIDENCE BECAUSE THERE ARE NO CLINICAL BIOMARKER, WE DON'T KNOW ABOUT HOW LONG IT CAN SURVIVE IN VIVO, WE DON'T KNOW ABOUT THE PERSISTENCE, WE DON'T KNOW WHAT THE REACTIVATION QUEUES ARE, WE DON'T KNOW WHAT DRUG TARGETS IT EXPRESSES AND WHAT DRUGS IT MIGHT BE SENSITIVE TO. SO WE SET OUT TO DEVELOP AN IN VITRO MODEL OF THIS ORGANISM IN OUR TWO-DIMENSIONAL LIVERS THAT I SHOWED YOU EARLIER.
SO THE MODEL SYSTEM THAT WE DEVELOPED USING HUMAN HEPATOCYTES LOOKS A LOT LIKE THE PICTURE I SHOWED YOU EARLIER BUT IT HAS ONE ADDITIONAL CELL TYPE. AND SO HERE WHAT WE'VE DONE IS PATTERN HUMAN HEPATOCYTES FROM ORGAN DONORS ON COLLAGEN TYPE 1, AND NOW WE SURROUND THEM WITH FEEDER CELLS, WITH FIBROBLASTS THAT SUPPORT THEIR PHENOTYPE. AND USING THIS MANIPULATION, WE'RE ABLE TO MAINTAIN THE HUMAN HEPATOCYTE PHENOTYPE IN A TWO-DIMENSIONAL CONSTRUCT IN THE BOTTOM OF A WELL FOR ABOUT FOUR TO SIX WEEKS. DEPENDING ON THE DONOR. AND WHAT'S INTERESTING AND WHAT WIN AND I SPENT A LOT OF TIME TALKING ABOUT OVER THE YEARS IS THESE CELLS ACTUALLY POLARIZE IN THIS CONFIGURATION. EVEN THOUGH THEY'RE IN A TWO-DIMENSIONAL MONO LAYER.
SO FOR EXAMPLE, IF YOU ADD A FLOOR SEEN DAIS TATE INTO THIS CULTURE, YOU CAN SEE THAT IT'S TAKEN UP AND PUT OUT INTO THE BIOCANULICULI JUST LIKE THEY DO IN VIVO. THEY ALSO EXPRESS DRUG METABOLIZING ENZYMES AND THEY HAVE LOTS OF UTILITY FOR MANY APPLICATIONS IN ADDITION TO STUDYING THE LIVER STAGE OF PATHOGENS. SO IN ORDER TO MAKE THIS USEFUL TO THE BIOMEDICAL RESEARCH COMMUNITY, WE MINIATURIZE THESE MICRO PATTERNED CO-CULTURES IN A WAY THAT WE COULD PUT THEM INSIDE OF MULTIPLE PLATES. SO WE'RE NO LONGER USING THE EXACT TECHNIQUES OF THE SEMICONDUCTOR INDUSTRY WHERE YOU PATTERN A SURFACE WITH LIGHT. INSTEAD HERE WE'RE BASICALLY MAKING STAMPS AND THEN WE'RE STAMPING INTO MULTI-WELL PLATES. AND THAT'S ALLOWED US TO MAKE DIFFERENT FORMATS OF THIS TOOL.
A 24-WELL VERSION, A 96-WELL VERSION, AND A 384-WELL VERSION. SO YOU CAN DO LOTS OF BIOLOGY WITH VERY FEW HUMAN HEPATOCYTES. OKAY. SO NOW I WANTED TO DO THE EXPERIMENT WITH VIVAX, AND I HAD A VERY ADVENTUROUS GRADUATE STUDENT AND THIS IS HOW HER THESIS WENT. SHE WOULD PATTERN THESE PLATES IN BOSTON, WAIT FOR THE RAINY SEASON IN THAILAND, WHERE VIVAX IS ENDEMIC, FLY WITH THE CELLS FROZEN AND THE PLATES TO OUR COLLABORATOR LAB IN THAILAND, WHERE THE LAB HAD COLLECTED BLOOD FROM INFECTED VIVAX PATIENTS IN THE FIELD AND FED THOSE TO MOSQUITOES AND THEN ISOLATED SPORE ZOITES FROM THOSE MOSQUITOES THAT WE COULD PUT INTO THE CULTURE. SO WE WOULD THEN PUT THESE INTO OUR MOO CROW PATTERN COCULTURES, DO THE EXPERIMENT, TYPICALLY IT LASTED 21 DAYS, TAKE SOME OF THE PLATES AND FIX THEM, BRING THEM BACK TO BOSTON TO THE BROAD INSTITUTE, WHERE WE WOULD USE MACHINE ALGORITHMS TO STUDY THE PARASITES OVER THE COURSE OF THEIR LIFE CYCLE, AND WITH THE OTHER PLATE, WE WORKED WITH ALEX SHALAK TO DO SINGLE CELL SEQUENCING OF THE INFECTED HEPATOSITES.
SO HEPATOCYTES. SO WE WOULD DISPERSE THOSE CULTURES AND PUT THEM INTO A FORMAT THAT ALEX HAS INVENTED CALLED SEQ-WELL WHERE EVERY -- YOU CAN BARCODE THE RNA ON A PER-WELL BASIS. IF IT CONTAINED A HEPATOCYTE -- IF IT HAD BOTH THE HEPATOCYTE AND A PATHOGEN, IT COULD CARRY BOTH OF THEM ON THE SAME BARCODE.
SO WHAT DID WE LEARN? LET ME JUST SHOW YOU SOME PICTURES OF THIS KIND OF ELUSIVE PARASITE BECAUSE WE WERE SO HAPPY TO HAVE GROWN IT AFTER 10 YEARS OF WORK ON WORKING ON IT. SO WHAT YOU'RE LOOKING AT NOW IS A CULTURE, AND THIS IS A HISTOGRAM OF THE PARASITES INSIDE THAT CULTURE. AND HERE WE'RE STAINING THE VACUOLE, SO THIS IS A MEMBRANE THAT SURROUNDS A PARASITE INSIDE THE HEPATOCYTE. THIS IS THE HEPATOCYTE NUCLEI WITH UIS4, AND WE'RE MARKING ITS GENOME WITH THIS HISTONE ACETYLATION MARKER.
YOU CAN SEE IN THE BEGINNING ALL THE PARASITES ARE QUITE SMALL. AS WE LET THESE GROW, LOOKING AT DAY 8, WE SEE SOME OF THE SMALL FORMS AND WE SEE SOME THAT HAVE BEEN HIGHLY MULTINUCLEATED. SO THESE HAVE REPLICATED. IN PATIENT BIOPSIES, THE BIGGEST ONE OF THESE THAT HAD BEEN NOTED PREVIOUSLY WAS ABOUT 40 MICRONS. IN OUR CULTURES, WE SEE THEM TO BE UP TO 130 MICRONS.
YOU CAN SEE THEY JUST TAKE UP THE WHOLE HEPATOCYTE CYTOPLASM. THEN IF YOU WAIT A LITTLE LONGER, ON DAY 10, THIS IS THE FIRST TIME WE BELIEVE ANYONE HAD EVER SEEN THIS IN VITRO, YOU CAN SEE THE STRUCTURE BURSTING OUT, AND THESE MARAZOITES COMING OUT OF THE HEPATOCYTES, STREAMING OUT >>, AND THIS IS WHEN THEY WOULD ENTER INTO THE BLOOD STAGE IN THE BODY. THIS IMAGE, I SHOULD SAY NEIL WAS SO HAPPY TO SEE THIS, SHE TOOK THIS IMAGE THROUGH THE MICROSCOPE OBJECTIVE WITH HER IPHONE BECAUSE WE HAVE NO VIDEO MY MICROSCOPY. SO IF WE OVERLAY RETICULOCYTES, YOUNG RED BLOOD CELLS ON TOP OF THESE CULTURES, IN FACT, THEY CAN COMPLETE THEIR FULL LIFE CYCLE AND INFECT THE RED BLOOD CELLS. AND THEN IF WE LOOK AT WHAT'S LEFT IN THE CULTURE AFTER 21 DAYS, ALL WE SEE ARE THESE SMALL PERSISTENT FORMS, WHICH WE THINK ARE HYPNOZOITES.
THERE ARE NO BIOMARKERS DEFINITIVE FOR THEM, SO WE WANTED TO SEE IF THEY REALLY MIGHT CARRY ALL OF THE HALL MARKS THAT ARE KNOWN CLINICALLY TO DESCRIBE HYPNOZOITES, AND THERE ARE FOUR OF THEM. SO THE FIRST IS THAT THEY ARE SMALL, QUIESCENT, MONO NUCLEATE, AND PERSISTING. WHICH WE FOUND. THE SECOND IS THAT WHILE THEY DO EXPRESS MARKERS LIKE UIS4, THEY SHOULD NOT EXPRESS MATURE MARKERS LIKE MARAZOITE SURFACE PROTEIN, WHICH IS ON THE SURFACE OF THESE REPLICATING FORMS THAT ARE ABOUT TO COME OUT INTO THE BLOOD, AND YOU SEE THEY ARE MSP1 NEGATIVE. THE THIRD, AND THIS IS VERY IMPORTANT, WE LEARNED THIS FROM PATIENTS, IS THAT THESE ORGANISMS SHOULD BE DIFFERENTIALLY DRUG-SENSITIVE. THAT IS THAT THEY SHOULD BE SENSITIVE TO A DRUG LIKE PRIAQUINE, AND YOU SEE THEY ARE, BUT THEY SHOULD BE INSENSITIVE TO A DRUG THAT ONLY KILLS REPLICATING FORMS LIKE ATOVAKWAN.
THE SMALL FORMS PERSIST. THIS IS THE THIRD HALLMARK. THE FOURTH HALLMARK SHOULD BE THAT THE DORMANT FORMS ARE CAPABLE OF REACTIVATING.
HERE WE GOT LUCKY, SOMETIMES IN SCIENCE YOU GET LUCKY, WHICH IS THAT IN SOME OF THE CULTURES, WE WAITED, AND AFTER THEY WERE CLEARED COMPLETELY OF THOSE LARGE FORMS THAT BURST OUT ON DAY 10, WE CAME BACK A WEEK OR TWO LATER AND SAW THE DORMANT NUMBER HAD DECREASED AND WE NOW FOUND THESE LARGE REACTIVATED FORMS. SO WE HAVE ESSENTIALLY ALL FOUR HALLMARKS OF HYPNOZOITES IN VITRO THAT WE BELIEVE TO BE CONSISTENT WITH CLINICAL DATA, SO WE WERE BRAVE ENOUGH TO CALL THIS A HYPNOZOITE WHEN WE PUBLISHED OUR PAPER IN 2018. NOW WE'VE SEEN IT MANY, MANY TIMES, THERE'S LOTS TO STUDY ABOUT IT, AND FOR THOSE OF YOU WHO ARE INTERESTED IN NEW EXCITING RESEARCH PROJECTS, THESE ARE JUST SOME OF THE THINGS THAT WE'VE BEEN DOING WITH THIS MODEL SYSTEM AND SHARING IT WITH THE COMMUNITY. YOU CAN DO THE TRANSCRIPTIONAL PROFILE OF THIS ORGANISM AND I'LL SHOW YOU SOME OF THAT IN A SECOND, YOU CAN STUDY THE MECHANISMS OF DORMANCY AND REACTIVATION, SEXUAL COMMITMENT IN THE ORGANIZE ORGANISM, WHICH IS THOUGHT TO HAPPEN IN THE BLOOD STAGE. NOW THAT WE HAVE THIS TOOL TO STUDY THIS FORM IN VITRO, THERE'S LOTS TO DO. SO LET ME TELL YOU ONE OF THE NEWER STORIES QUICKLY ABOUT THIS ORGANISM THAT'S ABOUT TO BE PUBLISHED THAT HAS TO DO WITH THIS DUAL SEQUENCING.
SO I DESCRIBED THIS TO YOU EARLIER, WHERE WE DISPERSED THE CULTURE INTO SINGLE WELLS AND EVERY WELL IS BARCODED. AND WHAT WE DID WHEN WE DID THIS EXPERIMENT WAS WE FOUND 1400 PARASITE GENOMES AND 33,000 HEPATOCYTES. SOME WERE INFECTED, SOME WERE UNINFECTED. WE COULD TELL WHICH WERE UNINFECTED BECAUSE THEY HAD THE SAME BARCODE. THESE ARE SOME OF THE THINGS THAT WE'VE LEARNED IN THIS STUDY. SO ONE OF THEM IS THAT WE COULD SEE THE PARASITE MATURING OVER THE FIRST TWO WEEKS OF LIFE.
SO WHAT WE DID WAS WE TOOK THE TRANSCRIPTOME THAT WE PREVIOUSLY HAD DONE IN THE INITIAL EXPERIMENT AND CREATED A 10-GENE SIGNATURE FOR THE HYPNOZOITE, THE DORMANT FORM, BASED OFF OF THE ORIGINAL DATA. AND THEN WE APPLIED IT TO THE SINGLE CELL DATA. AND THERE'S SOME VERY INTERESTING GENES HERE.
ONE OF THEM IS A TRANSLATIONAL REPRE SER, WHICH SEEMS TO BE IMPORTANT FOR QUIESCENCE. TWO OF THEM ARE ACTUALLY PROTEASES, AND THERE'S SOME SUGGESTION THAT PROTEOLYSIS OF HOST PROTEINS IS IMPORTANT FOR THE PARASITE TO PERSIST. AND THEN ONE OF THEM IS ACTUALLY MDR2, WHICH MAKES ONE WONDER ABOUT RESISTANCE TO DRUGS. SO THIS IS A SIGNATURE FOR THE HYPNOZOITE.
AND NOW, WHEN YOU FOLLOW THE PARASITE AROUND ITS LIFE CYCLE OVER TIME IN THE LIVER, YOU SEE THAT THE DAY ONE FORMS CLUSTER TOGETHER. THESE ARE THOSE SPORE ZOITES THAT CAME OUT OF THE MOSQUITO INTO THE LIVER. THE MIDDLE FORMS HAVE TWO CLUSTERS, AND THIS CLUSTER HERE CARRIES ALL THOSE HYPNOZOITE GENES, AND AS THEY MATURE, THERE'S A FORM THAT'S STILL IN HEPATOCYTES HERE AND THIS THAT'S BURST OUT. SO YOU CAN ANNOTATE THESE AS WE GO.
WHAT'S REALLY INTERESTING ABOUT THIS, AND I'LL SHOW YOU AT THE END, IS THAT YOU CAN EVEN ASK WHETHER ANY OF THESE HAVE COMMITTED ALONG THE SEXUAL DIFFERENTIATION PATH, WHICH AGAIN WAS THOUGHT TO OCCUR ONLY IN THE BLOOD STAGE. SO WE'RE STARTING TO GET A SENSE FOR THE LIFE CYCLE OF THIS ORGANISM, AND THIS IS JUST THE PARASITE. THEN YOU MIGHT ASK, HOW IS THE HEPATOCYTE RESPONDING TO THIS INFECTION? SO HERE NOW, THESE ARE THE 33,000 HEPATOCYTES. YOU CAN SEE HOW THEY CLUSTER LARGELY TOGETHER. WE HAVE EIGHT DIFFERENT SUBTYPES IN THIS SAMPLE. WHAT'S INTERESTING TO ASK HERE IS, WHICH CELLS ARE INFECTED? SO IF YOU LOOK IN THESE EIGHT DIFFERENT CLUSTERS, WHICH ARE INFECTED, YOU SEE ACTUALLY ALL THE CLUSTERS CARRY INFECTION.
SO THERE'S NO PREDOMINANT HEPATOCELLULAR PHENOTYPE THAT'S MORE PERMISSIVE. THE ONLY THING THAT ABOUT 60% OF THESE SHARES SOLD HAD IN COMMON WAS SRD1, AND WE CONFIRMED THAT IN OUR DATA AND VALIDATED THAT RESULT. SO THE ONE THING THAT CAME UP IN IN MANY OF THE CULTURES WERE INTERFERON PATHWAY-RELATED GENES, OR SO CALLED ISG OR INTERFERON STRESS GENES. SO HERE YOU CAN SEE TWO OF THEM, IFI6 AND IFI-T1, AND THEY'RE SORT OF SCATTERED AMONG THE NAIVE HEPATOCYTES AND THOSE THAT HAVE JUST BEEN EXPOSED WITH MALARIA SALIVARY GLAND MATERIAL. THAT'S CALLED A MOCK EXPOSURE. YOU CAN SEE WHEN YOU EXPOSE A CULTURE TO VIVAX ITSELF, THAT MANY OF THE HEPATOCYTES LIGHT UP WITH THESE ISGs.
NOT JUST THE INFECTED HEPATOCYTES, AND, IN FACT, THE INFECTED HEPATOCYTES, THE PARASITE SEEMS TO SUPPRESS THE RESPONSE TO INFECTION, BUT THE BYSTANDER HEPATOCYTES ACTUALLY UPREGULATE ALL OF THESE INTERFERON RESPONSES. SO THIS IS A LOT OF DATA, IT'S ABOUT TO COME OUT. I JUST WANTED TO GIVE YOU A SNIPPET AND TO SUMMARIZE THE TWO THINS THAT WE'RE LEARNING AND THE CONVERSATION BETWEEN THE HOST AND THE PARASITE THAT THIS SYSTEM, I HOPE, WILL ALLOW US TO UNWIND.
AS ON THE HEPATOCYTE SIDE, THE INFECTED HEPATOSIDE DOWN REGULATES THE INTERFERON RESPONSE. AND THE BYSTANDER HEPATOCYTES UPREGULATE THE RESPONSE. BASED ON SOME OTHER DATA THAT HEPATOCYTES ACTUALLY MEDIATED BY GAP JUNCTIONS. THIS IS SOMETHING SIMILAR THAT CHARLIE RICE AND I SAW WHEN LOOKING AT HEPATITIS C, SO THERE'S SOMETHING VERY INTERESTING HAPPENING HERE JUST ON THE HOST RESPONSE SIDE. IF YOU ADD INTERFERON GAMMA INTO THIS CULTURE, YOU ACTUALLY CAN USE TO CLEAR HYPNOZOITES. ON THE PARASITE SIDE, I MENTIONED TO YOU THAT THERE ARE THESE VARIOUS SUBSTRUCTURES IN THE DATA, ZOITES ARE HERE.
IF YOU ACTUALLY LOOK, WE'VE FOUND A MASTER REGULATOR SEXUAL DIFFERENTIATION CALLED AP2G, THOUGHT TO ONLY BE UPREGULATED IN THE BLOOD STATE YOUR NAME. WE STAGE. WE FOUND IT HERE IN THE LIVER FROM THE VERY BEGINNING, FROM DAY ONE. WE SEE THAT SOME OF THE HYPNOZOITES ACTUALLY CARRY THIS AND SOME OF THE REPLICATED FORMS.
AND THIS IS ACTUALLY REALLY INTARIQING BECAUSE THERE ARE SOME DATA IN THE MALARIA COMMUNITY IN CHALLENGE EXPERIMENTS WHERE PATIENTS HAVE SHOWN THE ABILITY TO BE TRANSMISSIBLE AT DAY 9 AFTER INFECTION. WHICH EVERYONE ALWAYS THOUGHT WAS WAY TOO EARLY, BECAUSE THEY'RE SUPPOSED TO COME OUT OF THE LIVER AT DAY 10 AND THEN GO INTO THE BLOOD STAGE AND THEN UNDERGO SEXUAL DIFFERENTIATION BEFORE YOU COULD BE TRANS MISSABLE. THESE DATA SUGGEST IT'S DEVIATING SEXUALLY EVEN IN THE LIVER STAGE. SO FROM A TRANSLATIONAL PERSPECTIVE, IT MAY SUGGEST THAT SOME OF THE DRUGS THAT ARE BEING DEVELOPED AGAINST THE SEXUAL STAGES OF THE ORGANISM MIGHT ACTUALLY BE USEFUL FOR TARGETING THE LIVER STAGE.
OKAY. SO THIS IS MY FIRST VIGNETTE. IT'S AN EXAMPLE OF WHAT A 2D MICROENVIRONMENT OF HUMAN HEPATOCYTES IN VITRO MIGHT ALLOW YOU TO DO FOR INFECTIOUS DISEASE.
THE LAST THING I'D LIKE TO MENTION FROM A TOOL PERSPECTIVE IS THAT THE DEVELOPMENT OF TOOLS CAN REALLY OPEN UP NEW DOORS. SO WE STARTED THIS IN 2008, AND IN THE BEGINNING, WE WORKED ON HEPATITIS C AND HEPATITIS B WITH CHARLIE RICE. AND THEN VALCIPRIN AND VIVAX, AND THIS TOOL HAS BEEN USINGED BY A VARIETY OF LABS REALLY AROUND THE WORLD, AS I MENTIONED TO STUDY MANY, MANY TOPICS, INCLUDING VACCINES, AND WE'RE NOW JUST GETTING TO THE NOVEL THERAPEUTIC ACTIVITY, THINGS LIKE RNA INTERFERENCE AND CRISPR, AND GENE DELIVERY. SO THIS VERY SIMPLE TOOL, I THINK ACTUALLY HAS A LOT TO OFFER.
SO THAT'S MY FIRST VIGNETTE. THE SECOND ONE I'D LIKE TO MENTION IS ABOUT THREE-DIMENSIONAL HEPATIC MICRO ENVIRONMENTS. SO I SHOWED YOU BEFORE THAT SEMICONDUCTOR TOOLS ALLOWED US TO WRITE ON SURFACES. THOSE SAME TOOLS CAN BE USED TO MOLD AND TEMPLATE AND PRINT THREE-DIMENSIONAL MATERIALS.
SO WHAT YOU SEE HERE ARE SOME IMAGES OF A VARIETY OF DIFFERENT STRUCTURES MADE USING MICRO FABRICATION TOOLS BUT IN THREE DIMENSIONAL FORMS. FOR EXAMPLE, THIS IS A MICRO FLUIDIC STRUCTURE THAT'S MAKING LITTLE HEPATIC 3D MICRO TISSUES. SO WHAT I'D LIKE TO DO IS TELL YOU A STORY ABOUT 3D MICRO ENVIRONMENTS IN THE CONTEXT OF ANOTHER REALLY FASCINATING MEDICAL CHALLENGE, WHICH IS LIVER REGENERATION. SO JUST TO KIND OF ORIENT YOU HERE, THIS IS A STORY WHICH AS FAR AS I KNOW START IN 1930s, ALTHOUGH WIN MAY KNOW AN OLDER STORY, WHERE ONE CAN DO A PARTIAL HEPATECTOMY IN WHICH THE LIVER REGENERATES WITHIN WEEKS. THERE'S MANY FASCINATING THINGS ABOUT THIS, BUT ONE THAT'S ALWAYS FASCINATED OUR WORK HAS BEEN THE WORK OF NANCY BOOKER, WHICH DATES BACK TO THE 1950s.
A PARABIOSIS EXPERIMENT, WHERE THE CIRCULATION OF TWO ANIMALS WAS CONNECTED AND A PARTIAL HELP TECT MEE WAS DONE IN THE ONE AND THE OTHER LIVER COULD ACTUALLY RESPOND TO THAT INJURY. THAT SUGGESTED IN PART THAT THE SIGNALS INVOLVED WITH HEPATIC REGENERATION MUST BE BLOODBORNE OVER THE YEARS, GEORGE AND MANY OTHERS HAVE DUG INTO THIS, AND WHAT THEY'VE FOUND IS THAT IN PART, THE QUEUES IN HEPATIC REGENERATION ARE A CONVERSATION BETWEEN HEPATOCYTES IN THE LIVER AND THEIR NEIGHBORING CELLS, THE SINUSOIDAL AND EPITHELIAL CELLS. I'M KIND OF BLOWN UP WHERE YOU SEE THAT CONVERSATION HERE WHERE YOU SEE EPITHELIAL CELLS AND HEPATOCYTES, PART RESPOND TO INJURY, PART RESPOND TO FLUID FLOW, THESE CELLS START PRODUCING PARAFFIN FACTORS, SO FOR COMPACT, ENDOTHELIAL CELLS MAKE THINGS, AND THE HEPATOCYTES IN TURN MAKE GROWTH FACTORS. AND THAT ALLOWS THE HEPATOCYTES AND THE ENT THEEL YELL CELLS TO COORDINATE THEIR REPLICATION AS THE LIVER REGROWS. SO WE WANTED TO STUDY THE HUMAN ANALOG OF THIS. IT HAD BEEN REALLY WELL STUDIED IN RODENTS AND NOT WELL STUDIED IN HUMANS, SO WE WANTED TO SEE IF WE COULD MAKE A PATTERN OF INTERACTIONS AS THEY RELATE TO REGENERATION USING SOME OF THESE PD TOOLS.
SO THIS IS HOW WE DID IT. THE FIRST STEP WAS TO TAKE HUMAN HEPATOCYTES AND MAKE SPHEROIDS OUT OF THEM. WE DO THIS USING A MICRO FABL KATEED MOLDS, THEY FORM THESE AGGREGATES OF ABOUT 150 MICRONS IN DIAMETER. IN THIS STRUCTURE, THEY'RE STABLE IN CULTURE FOR WEEKS. THE FULL PHENOTYPE THAT I DESCRIBED. AND THEN WE WANTED TO PUT THEM CLOSE IN TRACKS WITH ENDOTHELIAL CELLS, AND IN ORDER TO DO THIS WORK, WE WORKED WITH MY COLLEAGUE, CHRIS CHEN AND BOSTON UNIVERSITY, WHO'S AN EXPERT IN VASCULAR BIOENGINEERING.
WHAT CHRIS AND HIS LAB HAD DONE, AND AS YOU SEE HERE, IS TAKEN ENDOTHELIAL CELLS, HUMAN VEIN ENDOTHELIAL CELLS, SO THEY'RE NOT SIGN SOY DAL ENDOTHELIAL CELLS BUT THEY ARE HUMAN CELLS, AND PUT THEM IN A CHANNEL, MICRO FABRICATED CHANNEL INSIDE A HYDROGEL. SO THIS IS A FIBRIN HYDROGEL. YOU CAN SEE THEY FORM THESE LOVELY JUNCTIONS THAT YOU COULD PUT FLOW THROUGH THIS CHANNEL, AND KRILS AND HIS LAB HAVE USED THIS TO STUDY ANGIOGENIC SPROUTING AND ANY NUMBER OF VASCULAR QUESTIONS.
SO WE WANTED TO PUT THESE TWO SYSTEMS TOGETHER AND GET THE HEPATOCYTES TO TALK TO THE ENDOTHELIAL CELLS AND SEE IF WE COULD STUDY LIVER REGENERATION. SO WE MADE A LITTLE CHIP, WE CALLED IT SHEER, WHERE THERE'S A PANEL IN THE MIDDLE THAT HAS THE HUMAN ENDOTHELIAL CELLS AND THE SPHEROIDS AROUND THEM AND ASK HOW THEY RESPONDED TO VARIOUS STIMULI. AND TO TAKE THIS CONVERSATION THAT WE WERE INTERROGATING BEFORE AND SEE WHETHER WE COULD LEARN ANYTHING NEW ABOUT IT IN A HUMAN CONTEXT. SO WE DID THESE EXPERIMENTS, WE CAN ADD THINGS LIKE FLOW, YOU CAN SEE THAT THE CELLS THEN WILL PRODUCE A VARIETY OF DIFFERENT FACTORS IN THE PRESENCE OF FLOW BECAUSE THE ENDOTHELIAL CELLS ARE TOO SENSITIVE TO SHARE, THEN WE COULD ADD INFLAMMATORY CYTOKINES LIKE THOSE THAT YOU MIGHT SEE IN INJURY, LIKE IL-1 BETA.
NOW YOU SEE A WHOLE BUNCH OF FACTORS COMING UP IN THE MEDIA, AND ONE THING THAT WE WERE REALLY INTRIGUED BY WAS THIS ONE, PROSTAGLANDIN E2. OUR COLLEAGUE HAD PREVIOUSLY REPORTED THAT THIS WAS INVOLVED ACTUALLY IN ZEBRAFISH LIVER REGENERATION. SO WE'RE VERY INTERESTED TO SEE IT HERE. SO THE QUESTION BECAME FOR US, WHO IS MAKING THE PGE2 IN THIS SYSTEM, AND HOW IS IT WORKING IN THIS SORT OF CONVERSATION BETWEEN HEPATOCYTES AND ENDOTHELIAL CELLS? SO RE WE PUT A CELL CYCLE REPORTER AND LOOKED AT CYCLING HEPATOCYTES IN RESPONSE TO THESE SIGNALS, AND WE COULD SEE THAT IN THE PRESENCE OF IL-1 BETA, WE SAW THEM ENTERING THE CELL CYCLE, AND IN THE PRESENCE OF ENTERING THE CYCLE. SO THE QUESTION WE HAD WAS, WHETHER THIS PROSTAGLANDIN E IT WAS E2 WAS BEING PRODUCED BY THE ENDOTHELIAL CELLS AND ACTUALLY MEDIATING THIS ENTRY INTO THE CELL CYCLE.
SO BECAUSE WE'RE IN AN IN VITRO SYSTEM, WE CAN JUST MANIPULATE THE CELLS GENETICALLY INDIVIDUALLY, SO WE DID THAT. WE TOOK THE ENDOTHELIAL CELLS, WE USED CRISPR, WE MAPPED OUT PGE SYNTHASE WHICH ALLOWS US TO PRODUCE PGE2 IN THE ENDOTHELIAL CELLS AND DID THE SAME EXPERIMENT AND ASKED WHAT HAPPENS, AND SO WHAT YOU SEE IS, HERE'S A CONTROL EXPERIMENT, SO NOW IN THE PRESENCE OF IL-1 BETA, THE CELLS ARE CYCLING. AND NOW IN THE PRESENCE OF IL-1 BETA, WITH THE ABSENCE OF PGE IN ENDOTHELIAL CELLS, THE CELLS NO LONGER CYCLE. SO ALL OF THE IL-1 BETA INDUCED CYCLING IN THIS SYSTEM SEEM TO BE DEPENDENT ON PGE2 FROM THE ENDOTHELIAL CELLS.
SO THIS ALLOWS US NOW TO HAVE A WORKING MODEL WHERE WE THINK THAT THE ENDOTHELIAL CELLS IN HUMAN LIVER REGENERATION ARE MAKING PGE2 AND CONTRIBUTING TO HEPATOCYTE CELL CYCLE ENTRY. THE TRANSLATIONAL IMPLICATIONS ARE VERY INTERESTING BECAUSE OF COURSE THE PROSTAGLANDINS HAVE A SET OF GPCR RESPEP RECEPTORS AND TARGETING THEM COULD ACTUALLY PRODUCE HEPATOCYTE PROLIFERATION THERAPEUTICALLY, SO THAT'S THE IMPLICATION OF THIS WORK. SO THAT WAS IN VITRO EXPERIMENT. WE WANTED TO GO BACK THEN AND ASK HOW THIS WORKS RELATES TO WHAT NANCY BOOKER SAW IN VIVO. SO HOW WOULD THESE TYPES OF CONSTRUCTS REACT TO A REAL IN VIVO LIVER INJURY.
AND IN ORDER TO DO THAT, WE MADE AN IMPLANTABLE VERSION OF THESE CHIPS. SO NOW WE HAVE A MULTICHANNEL SYSTEM, AND WE SURROUND THOSE MULTIPLE CHANNELS WITH THE HEPATOCYTE SPHEROIDS, AND WE EMBED THE WHOLE THING IN FIBRIN, WHICH IS A HYDROGEL, AND WE CAN MAKE IMPLANTABLE STRUCTURES THAT LOOK LIKE THIS IN THE MICROSCOPE AND LOOK LIKE THIS ON THE TIP OF YOUR GLOVE. SO THIS IS ABOUT A 1 CENTIMETER IMPLANT. AND WE PUT THEM IN THE INTRAPERITONEAL SPACE OF A MOUSE, WHERE WE CAN MANIPULATE THE LIVER AND ASK HOW THESE GRAPHS RESPOND.
SO HERE YOU CAN SEE THE EXPERIMENT. THESE GRAPHS NOW CARRY A REPORTER FOR HEPATOCYTE HEALTH, SO THIS IS DRIVEN BY THE ALBUMEN GENE, AND IT'S LUCIFERASE. SO ESSENTIALLY WHAT YOU SEE IS THAT THE GRAPHS WILL ENGRAFT IN THE PERITONEAL SPACE BY RECRUITING VASCULATURE, AND THAT RECRUITMENT OF VASCULATURE IS REALLY DEPENDENT ON THE ENDOTHELIAL CELLS IN OUR CONSTRUCT. AND THEY PERSIST FOR ABOUT 90 DAYS IN THESE ANIMALS, WHICH IS PLENTY OF TIME TO DO SORT OF A SURGICAL OR CHEMICAL INJURY TO THE LIVER. SO WHEN WE DO THAT SAME EXPERIMENT, THE PARTIAL HEPATECTOMY TO THE MOUSE LIVER AND ASK WHAT HAPPENS TO THIS GRAFT IN THE PERITONEAL SPACE, WHAT WE SEE IS THAT THE HEPATOCYTES, A FEW PERCENT OF THEM, ABOUT 5% OF THEM, ENTER INTO CELL CYCLE. WE SEE THAT BY USING AN ANALOG WE GIVE THE ANIMALS, AND YOU CAN SEE THIS IN THE HEPATOCYTES.
SO THIS IS VERY INTERESTING, BUT IT WAS A TRANSIENT EFFECT, BECAUSE WHEN THE MOUSE LIVER REGROWS, THE REGENERATIVE STIMULUS WENT AWAY. SO WE WANTED TO ASK WHETHER WE COULD GET THESE ECTOPIC LIVERS, IF YOU WILL, TO PROLIFERATE EVEN FURTHER BY CREATING A SUSTAINED INJURY SIGNAL IP IN VIVO. WE DID THAT USING THE SO CALLED FAH MOUSE, WHICH IS A MOUSE MODEL OF A HUMAN DISEASE.
IT'S A TYROSINEMIA. THIS HAS BEEN POPULARIZED BY THE GROUP. AND IF YOU FEED THE MOUSE A PROTECTIVE DRUG, NTBC, THE ANIMALS ARE FINE.
IF YOU TAKE THEM OFF THE DRUG, THEY DEVELOP TOXIC LEVELS OF TYROSINE, WHICH IS A LIVER INJURY, AND YOU CAN CONTINUE THAT PROCESS WHICH WILL MAINTAIN A STEADY STATE OF LIVER INJURY. SO WE ASK WHAT WOULD THE RESPONSE OF OUR HUMAN GRAFTS TO THIS CHRONIC LIVER INJURY BE, AND WHAT YOU SEE HERE IS YOU ESSENTIALLY EXPAND PRETTY DRAMATICALLY, SO ABOUT 50 FOLD. SO HERE ON THE LEFT, YOU'RE LOOKING AT HEPATOCYTES STAINED FOR ARNLG ARGENASE, YOU CAN SEE THE HEPATOCYTES HAVE EXPANDED.
INTERESTINGLY, REORGANIZED. IF YOU LOOK NE BLOOD OF THOSE ANIMALS, YOU CAN TRACK HUMAN ALBUMIN AT ABOUT A 50 FOLD INCREASE. SO WE'VE BEEN REALLY INTERESTED IN THIS SORT OF CONCEPT NA A CONCEPT -- WE 'VE STARTED TO THINK ABOUT WHETHER THIS MIGHT BE THERAPEUTICALLY USEFUL. SO JUST TO SORT OF WALK YOU THROUGH OUR THINKING, ESPECIALLY FOR DISEASES, FOR EXAMPLE, SINGLE GENE DEFECTS THAT DON'T REQUIRE MUCH ENZYME TO BE THERAPEUTICALLY IMPORTANT, EVEN TODAY WHAT WE DO IS WHOLE ORGAN TRANSPLANTATION. SO YOU TAKE THE UREA CYCLE DISORDERS, THOSE PEDIATRIC PATIENTS ARE TRANSPLANTED WITH LIVERS. SO IT'S REALLY A WHOLE REPLACEMENT APPROACH.
SO THE FIELD HAS BEEN INTERESTED IN A LONG TIME WHETHER WE COULD ACTUALLY JUST INFUSE HEPATOCYTES THEMSELVES WITHOUT REMOVING THE LIVER AND REPLACING IT COMPLETELY, AND THESE EXPERIMENTS, THERE'VE BEEN ABOUT 100 CASE STUDIES IN PATIENTS THAT HAVE LARGELY BEEN DISAPPOINTING, THAT WE'VE LEARNED A LOT FROM THIS FIELD, BUT INJECTING CELLS INTO THE LIVER HAS A VARIETY OF CHALLENGES. ONE OF THEM IS THAT THEY DON'T ENGRAFT EFFICIENTLY. SO WE LOSE 90-PLUS PERCENTAGE OF THOSE HEPATOCYTES ALONG THE WAY. SO OUR THINKING HAS BEEN TO BUILD OFF OF OUR PRE-CLINICAL DATA. PERHAPS WE CAN JUST LEAVE THE LIVER IN PLACE AND ADD A PERITONEAL GRAFT OF HUMAN HEPATOCYTES THAT HAVE BEEN ENG FEARED TO BE IMPLANTED AND RECRUIT VASCULATURE AND SUPPORT THE PATIENT, KIND OF LIKE A BOOSTER. SO WE ARE ACTUALLY -- WE HAVE A STARTUP COMMITTEE I MENTIONED EARLIER THAT IS ATTEMPTING TO DO THAT, WHICH WE'LL BE FILING AN IND FOR FIRST PATIENT TRIALS, WE HOPE IN ABOUT A YEAR.
SO WHAT I'VE TOLD YOU ABOUT THE LIVER IS THAT WE CAN STUDY IT IN TWO DIMENSIONS, AND THAT CAN ENABLE THE INVESTIGATION OF HUMAN PATHOGENS LIKE P. VIVAX. WE CAN STUDY IT IN THREE DIMENSIONS, FOR EXAMPLE, WE CAN STUDY REGENERATION THAT'S PATHWAYS THAT ARE SPECIFIC TO THE HUMAN. AND THAT WE ARE STARTING TO THINK ABOUT WAYS TO TRANSLATE SOME OF THESE THINGS TO PATIENTS, AND THIS IS JUST AN IMAGE OF A GRAFT THAT WE'RE WORKING ON THE MANUFACTURING OF THESE TO SCALE THEM UP. SO MY LAST VIGNETTE, I WANT TO TELL YOU A LITTLE BIT ABOUT DISREGULATED TISSUE ENVIRONMENT LIKE THE TUMOR MICROENVIRONMENT. AND NOT REALLY BUILDING IT UP SO MUCH WITH TOOLS LIKE ON A TWO-DIMENSIONAL PATTERN OR THREE-DIMENSIONAL PATTERN, BUT INSTEAD MAKING MATERIALS THAT ARE SO SMALL THAT THEY CAN ACTUALLY ENTER INTO THAT TISSUE MICROENVIRONMENT AND MAKE MEASUREMENTS THAT WOULD INFORM US SCIENTISTS. SO HERE WHAT WE'VE DONE IS MAKE NANOMATERIALS THAT CAN ENTER INTO THE TUMOR MICROENVIRONMENT TO QUERY IT.
SO TO SORT OF SET THE STAGE FOR THIS WORK, AND I KNOW I'M RUNNING SHORT ON TIME SO I WON'T BE AS LONG WITH THIS EXAMPLE, WE'VE BEEN REALLY INTERESTED IN OFFERING PHYSICIANS TOOLS TO MAKE INFORMED DECISIONS ABOUT PATIENT CARE. SO IF YOU JUST SORT OF THINK ABOUT THE LANDSCAPE OF CANCER CARE, YOU NEED TO ASSESS RISK, DETECT EARLY, MAKE A DIAGNOSIS, ASSESS TREATMENT RESPONSE, AND THEN MONITOR FOR SURVEILLANCE. SO THERE'S OBVIOUSLY MANY, MANY POINTS ALONG A PATIENT JOURNEY THAT WE NEED BETTER INFORMATION.
AND IN PARTICULAR, WITH REGARD TO OUTCOMES, WE KNOW THAT EARLY DETECTION ACROSS A WIDE VARIETY OF TUMORS LEADS TO BETTER OUTCOMES, SO THIS HAS BEEN A REAL AREA OF INTEREST FOR THE FIELD. HISTORICALLY WE HAVE SCREENED THINGS LIKE MAMMOGRAMS AND COLONOSCOPY, PRETTY HIGH INFRASTRUCTURE APPROACHES. SO THERE'S A FIELD EMERGING THAT YOU MAY WELL KNOW ABOUT, WHICH IS CALLED LIQUID BIOPSY, AND IN THIS FIELD, WHAT'S BEEN INTERESTING HAS BEEN TO TAKE A BLOOD SAMPLE AND TO TRY AND ESSENTIALLY -- TO LOOK AT SHED PRODUCTS OF CANCER IN THE CIRCULATION, FOR EXAMPLE, CELL-FREE NUCLEIC ACIDS.
WHILE THIS IS A VERY EXCITING FIELD, IT HAS MANY LIMITATIONS SO FAR AND IN PARTICULAR, IT'S VERY HARD TO DETECT TO DETECT TUMORS EARLY, WHEN THEY'RE SMALL. SO WE CAN AMPLIFY THOSE SIGNALS BY USING SOME OF THESE NANOMATERIAL APPROACHES. SO I'LL SHOW YOU WHAT I MEAN. IN PARTICULAR, WE'RE INTERESTED IN USING A CLASS OF ENZYMES THAT ARE KNOWN TO BE CANCER DISREGULATED AND THOSE ARE CALLED THE PROTEASES. SO THERE'S ABOUT 500 OF THEM IN THE HUMAN GENOME AND THERE ARE FIVE MAJOR CLASSES, AND THESE HAVE BEEN ASSOCIATED WITH REALLY ALL THE CANCER HALLMARKS. SO THEY'RE KNOWN TO BE DISREGULATED WITH CANCER TUMOR INITIATION, SURVIVAL, ANGIOGENESIS INNOVATION AND THE IMMUNE SYSTEM.
AND REALLY MOST FAMOUSLY, I THINK, MMP9 IS THE POSTER CHILD FOR THIS FIELD AS ONE THAT IS INVOLVED WITH THIS ANGIOGENIC SWITCH. SO DESPITE THEIR INVOLVEMENT WITH TUMOR PATHOGENESIS, THEY'VE BEEN REALLY DIFFICULT TO STUDY. THEY'RE EXPRESSED IN PRO FORMS, THEY'RE TYPICALLY ACTIVE LOCALLY, AND THEY ACTUALLY CAN EXIST WITH LOCAL INHIBITORS.
SO WE'RE REALLY INTERESTED TO SEE WHETHER WE COULD MAKE SOME SORT OF MULTIPLEX TOOL TO PROFILE THEIR ACTIVITY IN TUMORS IN A WAY THAT COULD BE AMPLIFIED AND GIVE US A WINDOW INTO TUMOR BIOLOGY. SO WE DID THAT BY INVENTING A CLASS OF MATERIALS THAT ARE WHAT WE CALL ACTIVITY-BASED SENSORS. SO HERE WHAT YOU'RE LOOKING AT IS A SOLID TUMOR SURROUNDING A BLOOD VESSEL. IN THIS BLOOD VESSEL, WE'RE DELIVERING NANOMATERIALS THAT ARE ABOUT 100 NANOMETERS IN SIZE, AND THEY ARE EXTRAVASATING FROM THE VESSEL, SO THEY'RE LEAKING OUT OF THAT VESSEL.
AND THEY ARE DESIGNED TO BE ACTIVATED BY PROTEASES THAT ARE IN THE TUMOR MICROENVIRONMENT. SO FOR EXAMPLE, MMP9, WHICH IS A PROTEASE WHICH CAN CATALYZE THE CLEAVAGE OF A PEPTIDE. SO ONE COPY OF THE PROTEASE COULD LIBERATE MANY, MANY PEPTIDES FROM A NANOMATERIAL. AND WE DESIGN THESE PEPTIDES SO THAT THEY ARE RESISTANT TO DEGRADATION IN THE BLOODSTREAM, WE DO THAT BY MAKING THEM OUT OF D AMINO ACIDS, AND THEN WE DESIGN THEM SO THAT THEY CAN BE CONCENTRATED BY THE KIDNEY INTO THE URINE AFTER ABOUT ONE HOUR. SO WHAT YOU FIND IS THAT ONE COULD ADMINISTER THIS MATERIAL, COLLECT THE URINE IN AN HOUR, AND ONE WOULD HAVE THE CLEAVAGE PRODUCTS ASSOCIATED WITH -- IN THE TUMOR INSTEAD NOW IN THE URINE SAMPLE.
SO SORT OF NONINVASIVE WINDOW TO THE TUMOR MICROENVIRONMENT. SO WE INVENTED THIS TOOL AND FIRST IN VITRO, HERE'S FOR EXAMPLE ONE OF THESE SENSORS SENSITIVE TO THROMBIN. WE THEN STARTED TO MAKE A WHOLE LIBRARY OF THESE MATERIALS SO WE COULD QUERY PROTEASES ACROSS MANY OF THE DIFFERENT CLASSES, WHEN I WHAT I MENTIONED.
WHEN I PUT THEM IN VIVO, THEY WORKED AS I DESCRIBED. FOR EXAMPLE, THIS IS A MATERIAL THAT'S SENSITIVE TO MMP2, AND IN A MOUSE MODEL OF LIVER FIBROSIS. SO THESE MATERIALS HAVE BEEN ADMINISTERED INTRAVENOUSLY IN OUR LIVER TARGETED, AND IN THIS MOUSE MODEL OF FIBROSIS, WHERE THERE'S MMP2, THE MATERIALS ARE ACTIVATED. YOU CAN SEE IN AN HOUR THAT THE BLAH DIDDER IS LIGHTING BLADDER IS LIGHTING UP AS I SHOWED YOU IN THE VIDEO. SO THAT'S ONE THING. YOU CAN MAKE A HIGHLY SPECIFIC AND SENSITIVE TEST SO WE BARCODED THE SENSORS USING MASS SPECTROMETRY.
WE MAKE DIFFERENT MATERIALS WITH DIFFERENT TETHERS, AND EACH OF THE TETHERS, WHEN CLEAVED, WILL RELEASE A DIFFERENT BARCODE. SO YOU COLLECT THE URINE, AND THEN YOU CAN MASS SPEC THE URINE AND THAT GLIF YOU GIVE YOU A QUANTITATIVE READOUT OF EACH DIFFERENT SENSOR IN VIVO. OKAY. THAT'S A LOT TO DIGEST, BUT THIS IS BASICALLY HOW IT WORKS. YOU GIVE AN ENSEMBLE OF MATERIALS, THEY GO TO THE MICROENVIRONMENT OF INTEREST, THEY'RE ACTIVATED BY RESIDENT PROTEASES, AND THE FRAGMENTS, THE BARCODES, COME OUT AN HOUR LATER IN THE URINE. AND YOU CAN USE THIS POTENTIALLY AS A WINDOW INTO BIOLOGY IN THE BODY THAT WOULD BE DIFFICULT TO ACCESS OTHERWISE, AND BECAUSE OF THE AMPLIFICATION, WE'RE HOPEFUL THIS WILL ALLOW US EARLIER DETECTION OF THE DISEASE.
SO I'M GOING TO SKIP THE DETAILS ON THIS EXAMPLE WHERE WE'VE DONE IT FOR LUNG CANCER, BECAUSE I'M RUNNING SHORT ON TIME. AND JUST SORT OF SUMMARIZE THAT THIS IS A PRETTY LARGE BODY OF WORK THAT WE'VE NOW PUBLISHED, AND WHAT WE'VE LEARNED IS THAT THIS IS A HIGHLY SENSITIVE TOOL SO FAR IN MOUSE MODELS. SO IN MICE, WE CAN DETECT LESIONS THAT ARE ABOUT THREE CUBIC MILLIMETERS, AND SO FAR THIS IS QUITE A BIT MORE SENSITIVE THAN BOTH PROTEIN AND CIRCULATING DNA. IT'S HIGHLY SPECIFIC.
NOW OF COURSE ANIMALS ARE VERY -- WHEN WE GET INTO HUMAN POPULATIONS, WE HAVE TO SEE HOW MANY PROBES WE NEED REALLY TO MAKE THIS BOTH SENSITIVE AND SPECIFIC, BUT SO FAR WE CAN MULTIPLEX TO 19 PROBES AND WE'VE BEEN ABLE TO CLASSIFY THINGS VERY READILY. THEN WE'VE MADE A BUNCH OF DIFFERENT VERSIONS OF THESE SO YOU CAN HAVE NOT JUST A MASS SPEC-BASED TEST BUT AS I'LL SHOW YOU IN A MINUTE, YOU CAN DO THE READ YOWLT ON PAPER OR OUT ON PAPER OR BY BREATHALYZER, WHICH WE THINK MIGHT HAVE CLINICAL UTILITY. AS BEFORE, THIS WORK IS BEING TAKEN FORWARD BY A STARTUP, WHICH JUST FINISHED ITS PHASE 1 CLINICAL TRIAL OVER THE PANDEMIC AND IS POISED TO MOVE FORWARD TO ACTUALLY TRY AND REPLACE LIVER BIOPSY OR A DISEASE CALLED NASH, NON-ALCOHOLIC SEATTLE HEPATITIS. SO I KNOW I WENT QUICKLY THROUGH THAT EXAMPLE.
I JUST WANT TO TALK TO YOU A LITTLE BIT ABOUT HOW ONE MIGHT THINK ABOUT BUILDING ON THIS AND INTERFACING WITH CLINICIANS. SO IT'S POSSIBLE THAT URINE IS SUCH AN AMAZING BIOFLUID THAT WE COULD ENVISION MAKING A PAPER DIAGNOSTIC IN THE WAY YOU'VE ALL SEEN COVID DIAGNOSTICS. SO IN FACT, WE HAVE THE FOURPLEX VERSION OF THIS THAT WE'VE PUT ON PAPER. THAT WE ENVISION COULD BE USED AT THE POINT OF CARE.
IT STILL TAKES ABOUT AN HOUR TO DEVELOP. SO THE OTHER THING THAT WE WERE CHALLENGED TO DO BY ONE OF OUR CLINICAL COLLABORATORS WAS MAKE A BREATHALYZER FOR THE LUNG CANCER APPLICATION. SO WE'VE DONE THAT AND PUBLISHED THAT A COUPLE YEARS AGO NOW, AND WE'RE WORKING WITH A COMPANY IN THE U.K. CALLED ALSTONE. IN THIS USE CASE, WHAT'S DONE IS YOU INHALE THE SENSORS, AND WHEN THEY'RE ACTIVATED, INSTEAD OF TURNING FOO A URINE INTO A URINE READOUT, YOU EXHALE A VOLATILE, AND THE VOLATILE HAS ZERO BACKGROUND BECAUSE IT'S COMPLETELY SYNTHETIC.
SO IT'S VERY SENSITIVE AND THE PEAKS COME UP AT ABOUT 10 MINUTES, SO IT'S A 10-MINUTE TEST. AGAIN, WE'RE JUST GETTING STARTED, BUT WE ENVISION THAT THIS MIGHT BE A WAY FORWARD FOR SORT OF CHANGING DIAGNOSTICS. THEN THE LAST EXAMPLE I'LL GIVE IS, IF ONE, IN FACT, IDENTIFIES CANCER EARLY IN A PATIENT'S JOURNEY, THE VERY NEXT QUESTION AS A CLINICIAN, OR ONE NEXT QUESTION WOULD BE TO IDENTIFY WHERE THE LESIONS ARE.
SO WHAT'S THE TISSUE OF ORIGIN AND HAS THE TUMOR SPREAD. SO IN RECOGNITION OF THAT, WE MADE A VERSION OF THE SENSOR THAT NOT ONLY ALLOWS LONGITUDAL URINARY MONITORING, BUT WHEN THE URINE SIGNAL TURNS POSITIVE, YOU COULD LOAD THIS MATERIAL WITH A PET PROBE, SO THIS IS COPPER 64. AND IN THIS CASE, THEN, YOU CAN SEE THAT YOU CAN, IN THIS CASE IDENTIFY LIVER METASTASES WITH THE VERY SAME PROBE AFTER THE URINE TEST. SO THE IDEA HERE IS THAT MULTIMODAL AGENTS MAY BE HELPFUL TO CLINICIANS THAT ARE TRYING TO MAKE DECISIONS FOR PATIENTS. SO ON THE NANOSIDE, I'M SHOWING YOU THAT I THINK ENSEMBLES OF NANOSENSORS COULD BE USEFUL FOR MONITORING DISEASE.
I SHOWED YOU A CASE STUDY IN LUNG CANCER, AND SOME PRODUCT CONCEPTS THAT WE'RE TRYING TO TAKE FORWARD TO MAKE THIS USEFUL FOR OUR CLINICAL COLLEAGUES. I'D LIKE TO JUST CLOSE UP WITH SOME THOUGHTS ABOUT HOW TOOLS COULD BE USEFUL MORE BROADLY TO THE FIELD, AND JUST SORT OF OBSERVE THE MOMENT THAT WE'RE AT IN TIME. SO IN ORDER FOR THE TOOLS REALLY TO MAKE AN IMPACT ON MODERN MEDICINE, WE NEED DIFFERENT FIELDS TO COME TOGETHER.
YOU NEED TO CROSS THAT BRIDGE THAT WIN WAS ALLUDING TO. AND IN THE EXAMPLE I'VE GIVEN YOU, THE MINIATURIZATION REVOLUTION AND NUCLEIC ACID THERAPEUTICS AND MANY DIFFERENT STRANDS OF BIOLOGY HAVE COME TOGETHER, AND REALLY WE'RE POISED NOW, I THINK, IN THIS DECADE TO TACKLE SOME OF THE HARDEST PROBLEMS IN CANCER RESEARCH. EARLY DETECTION, RECALCITRANT TUMOR THERAPY, METASTATIC DISEASE, EVEN THINKING ABOUT GLOBAL ONCOLOGY. SO IT A REALLY EXCITING TIME TO THINK ABOUT BRIDGE BUILDING AND BRINGING THINGS TOGETHER TO TACKLE SOME OF THESE GRAND CHALLENGES.
MYSELF AND MY COLLEAGUES AT MIT WELCOME YOU TO COME VISIT US. WE THINK ABOUT THIS ALL THE TIME. WE HAVE ABOUT 200 TRAINEES IN OUR CENTER FOR NANOMEDICINE, THINKING ABOUT THIS SORT OF CONVERGENCE OF IDEAS.
AND THE LAST IMPORTANT INGREDIENT, I THINK, FOR MAKING AN IMPACT IS HAVING ALL THE RIGHT PEOPLE AT THE TABLE. SO THAT'S SOMETHING THAT I'VE REALLY WORKED ON OVER MY CAREER, AND I'LL JUST SHOW YOU SOME PICTURES IN THIS LAST MINUTE OR SO TO SHARE SOME OF THE THINGS THAT WE DO AT MIT ALONG THESE LINES. SO THIS IS AN OUTREACH WORKSHOP RUN BY THE SOCIETY OF WOMEN ENGINEERS FOR MIDDLE SCHOOL GIRLS TO BRING THEM TO MIT. THESE ARE ACTUALLY MY TWO DAUGHTERS. THEY'RE A LITTLE BIT OLDER NOW, ONE OF THEM IS IN COLLEGE.
THIS IS A SOCIAL MEDIA CAMPAIGN WITH TWO DEPARTMENT HEADS AT MIT. #I LOOK LIKE AN ENGINEER, TO CHANGE PERCEPTIONS OF ENGINEERING. THIS IS A POSTDOC PROGRAM TO DEVELOP LEADERS IN OUR POSTDOC COMMUNITY THAT WE RUN AND WE CALL IT THE CONVERGENCE SCHOLAR PROGRAM.
AND I'VE BEEN MOST RECENTLY WORKING ON WOMEN ENTREPRENEURSHIP, WOMEN FACULTY ENTREPRENEURSHIP AFTER HAVING COLLABORATED WITH SUSAN HOTFIELD AND NANCY HOPKINS AT MIT TO NOTE THAT WOMEN ARE UNDERFOUNDING COMPANIES IN THE LIFE SCIENCES. IF WE JUST LOOK AT MIT IN THE LAST 18 YEARS, THERE COULD HAVE BEEN 40 MORE COMPANIES FROM WOMEN FACULTY LABS. SO THIS IS AN OBSERVATION THAT WE'RE SHARING, AND WE HAVE LOTS OF IDEAS ABOUT HOW TO IMPROVE THAT, INCLUDING SOMETHING THAT I'M VERY PROUD OF THAT'S ONGOING NOW CALLED THE MIT FUTURE FOUNDER PRIZE COMPETITION. THEY HAVE THESE NINE AMAZING WOMEN PARTICIPATING. AND WE'LL BE STREAMING A SHOWCASE WITH THEIR PITCHES ONLINE ON MAY 5TH AS THEY START TO THINK ABOUT HOW TO BRING THEIR IDEAS FORWARD TO PATIENTS.
SO WITH THAT, THANK YOU VERY MUCH FOR YOUR ATTENTION. HOPEFULLY I'VE CONVINCED YOU THAT MAKING NEW TOOLS IS AN IMPORTANT PART OF FUTURE, AND I REALLY COULDN'T THANK MY LAB AND MY ALUMNI AND MY COLLABORATORS AND OUR FUNDING SOURCES ENOUGH. THANK YOU. >> SANGEETA, ON BEHALF OF EVERYONE, REALLY, THANK YOU FOR INTRODUCING MOST OF US TO THIS EXCITING NEW WORLD OF ENORMOUS POTENTIAL, GREAT EXCITEMENT AND GREAT OPPORTUNITY FOR BRIGHT YOUNG PEOPLE TO CONTINUE AND EXPAND THIS.
WE HAVE SEVERAL QUESTIONS THAT HAVE COME UP. ARE THERE SPECIFIC PROTEASES ASSOCIATED WITH SPECIFIC KINDS OF TUMORS, SO THAT THE ANALYSIS GIVES SOME CLUE AS TO THE IDENTITY OF THE TUMOR? >> YES, THIS IS A GREAT QUESTION. AND ONE THAT I GLOSSED OVER OUR KIND OF PIPELINE.
SO THERE ARE TUMOR-SPECIFIC -- THERE ARE BOTH TUMOR-SPECIFIC PROTEASES AND THERE ARE ALSO SORT OF PANCANCER PROTEASES. THE WAY WE FIND THE TUMOR-SPECIFIC ONES TYPICALLY IS TO START WITH THE CANCER GENOME ATLAS, WHICH IS A GREAT RESOURCE. AND JUST CLASSIFY THOSE 550. SO FAR EXAMPLE, IN THE LUNG CANCER MODEL THAT I SHOWED YOU, WE PICKED THE TOP 20 DISREGULATED CANCERS, PROTEASES, AND THEN ANOTHER FILTER THAT WE NEEDED TO ADD WAS ACTUALLY COMMON COMORBIDITIES THAT LUNG CANCER PATIENTS MAY HAVE, FOR EXAMPLE, IF THEY'RE SMOKERS OR THEY HAVE COPD, THOSE ALSO HAVE PROTEASES ASSOCIATED WITH THEM, SO WE DELETE THOSE FROM THE SIGNATURE SO THAT THEY'RE SORT OF SPECIFIC TO, IN THIS CASE, NON-SMALL CELL LUNG CANCER. >> ANOTHER INTERESTING QUESTION IS, CAN YOU VISUALIZE PERHAPS THAT NANOSENSORS BE DEVELOPED TO HELP MONITOR THE PROGRESSION OF TISSUE REGENERATION? FOR EXAMPLE, I'M SURE YOU KNOW THAT ONE OF THE BIG PROBLEMS IN LIVER INJURY IS TO DECIDE WHETHER A PATIENT NEEDS AN EMERGENCY TRANSPLANT OR WHETHER THE LIVER IS REALLY BEGINNING TO REGENERATE.
THIS IS STILL A VERY DIFFICULT QUESTION TO ANSWER. DO YOU THINK THERE IS SOME POSSIBLE ROLE OF NANOSENSORS IN A SITUATION LIKE THAT? >> I HAVEN'T THOUGHT EXACTLY ABOUT THAT USE CASE. SO IT WOULD BE FUN TO TALK MORE ABOUT IT, WIN.
BUT I THINK WHAT WE'VE SEEN, FOR EXAMPLE, IN JUST REJECTION, FOR EXAMPLE, WHICH IS T-CELL MEDIATED, BUT T-CELLS KILL BY GRANZYME, AND GRANZYME ACTUALLY IS A PROTEASE. SO MY FORMER POSTDOC PUBLISHED A VERY NICE PAPER COLLEAGUES AT EMORY SHOWING THEY COULD DETECT REJECTION EARLY USING A PROTEASE SENSOR. SO I DO THINK WITH 550 TO CHOOSE FROM, IT OFTEN THE CASE THAT WE CAN POINT IT AT A DISEASE. >> THERE WAS ALSO A QUESTION ABOUT IN STUDIES FROM THE PAST WHERE PEOPLE HAVE PUT HEPATOCYTES IN DIFFERENT MEDIA, COLLAGEN AND WHATNOT AND PLANTED THEM IN THE PERITONEUM, THAT WITHIN A SHORT PERIOD OF TIME, GUY PRO CYST OCCURS AND THE BLOOD SUPPLY IS CHOKED OFF AND THEY DON'T LIVE VERY LONG, AND I GUESS THE OTHER PART OF IT IS, THEY'RE SECRETING A DETERGENT PRESUMABLY OF BIOACID, WHICH ISN'T SO HEALTHY TO HAVE JUST FLOATING AROUND. SO WHAT IS THERE ABOUT YOUR PREPARATIONS THAT APPARENTLY THOSE EVENTS DON'T HAPPEN? WHY NOT? >> YEAH.
THAT'S A GREAT QUESTION AND ACTUALLY THE -- I THINK YOU KNOW, THE BILE DUCT QUESTION HAUNTED ME EARLIER IN MY CAREER. WE ARE TRYING TO BUILD A BILE DUCT BUT I THOUGHT WE HAD TO DO THAT FIRST UNTIL JIM BOIL AT YALE POINTED OUT TO ME THE HEPATOCYTES THAT PERSIST IN THE SPLEEN WHEN WE DO THOSE INJECTIONS ACTUALLY DON'T HAVE A BILE DUCT EITHER AND THEY DON'T BECOME CHOLESTATIC. THAT GAVE ME HOPE. SO ACTUALLY OUR INTRAPERITONEAL HEPATOCYTES ARE DOWNREGULATING THE BIOACID PRODUCTION AXIS, AND THE TRANSCRIPTIONAL DATA KIND OF SUPPORTS THAT, SO I THINK THAT'S WHY THEY'RE NOT TOX GUYING THEMSELVES WITH DETERGENT. THE REASON I THINK THEY'RE NOT FIBROSING IS BECAUSE OUR MATERIAL IS A DEGRADABLE MATERIAL, SO ONCE THE HEPATOCYTES GET VASCULARIZED, THE MATERIAL DEGRADES OVER THE COURSE OF A COUPLE OF WEEKS.
THERE'S NO FOREIGN BODY REACTION. >> THAT'S VERY INTERESTING. WE HAVE SOME QUESTIONS ABOUT THE MALARIA PROJECT.
IS THE HYPNOZOITE IN A SPECIAL COMPARTMENT, A MEMBRANE-LIMITED COMPARTMENT OR SOMETHING, AND WHAT MAKES IT DIFFERENT FROM THE OTHER SORT OF VACUOLES OR WHATEVER YOU CALL THEM, WHERE THE VIVAX IS THAT'S ACTUALLY BECOME ACTIVE? IS THERE SOMETHING SPECIAL ABOUT THE CELL BIOLOGY OF THE HIP ZOITE? >> THAT'S A GREAT QUESTION. SO FAR WE'VE STAINED ONLY FOR A COUPLE OF MARKERS OF THE VACUOLE AND SEEN NO DIFFERENCES IN THE MEMBRANE AROUND THE HYPNOZOITE VERSUS THE REPLICATING FORM. BUT AS I SORT OF BRIEFLY ALLUDED TO, IT DOES SEEM THAT THE HYPNOZOITE IS MAKING PROTEASES CALLED VIVOPANES. THEY SEEM IMPORTANT IN DIGESTING HOST PROTEINS AND MAINTAINING QUIESCENCE.
IF YOU INHIBIT THOSE, ACTUALLY THE PARASITE DIES, SO IT'S NOT CLEAR TO ME IF THAT SAME PROCESS IS LAPPING IN THE REPLICATING FORMS. >> VERY INTERESTING. I SEEM TO REMEMBER BUT I MAY BE WRONG ABOUT THIS, THAT THERE WERE PEOPLE INFECTED WITH VIVAX WHO RECOVERED FROM SEVERAL EPISODES AND THEN SEEM TO BE PERFECTLY NORMAL AND THEN MAYBE AS LONG AS FIVE YEARS, 10 YEARS LATER, FOR ONE REASON OR ANOTHER, THEY WERE GIVEN A CORTICOSTEROID FOR SOME -- DISEASE AND BINGO, THE VIVAX RETURNED IN ITS VARYING FORM. IS THERE SOME RELATIONSHIP BETWEEN THAT CLINICAL EVENT AND WHAT YOU'RE DESCRIBING IN THE CULTURED CELLS? >> YEAH, I THINK THESE ARE THE QUESTIONS WE CAN NOW ASK. THE OTHER ONE I'VE BEEN -- THE OTHER DATASET THAT'S REALLY FASCINATING IS THAT FROM OLD SORT OF MILITARY MOVEMENTS THAT VIVAX CLEARED SOLDIERS WHO WERE INFECTED WITH VALCIFIRIM, WOULD HAVE THEIR VIVAX FLARE. SO THERE'S A LOT OF INTERESTING HYPOTHESES I THINK WE COULD NOW TEST.
>> WELL, THAT'S VERY INTERESTING. WHY DID YOU PICK VIVAX AND NOT VALCIPIR MI OR ANY OF THE OTHERS? IS THERE SOME REASON? >> WE WANTED TO DO ANY OF THE HUMAN MALARIAS, SO ACTUALLY WE ACHIEVED VALCIPIRIM FIRST, BUT WE WANTED TO DO -- WE ALWAYS ARE TRYING TO DO SOMETHING WITH OUR TOOLS THAT HAD NEVER BEEN DONE, THAT NO OTHER TECHNIQUE COULD APPROACH. SO WE DID THAT AND OTHERS HAD DONE IT ACTUALLY PREVIOUSLY AND WE SORT OF MADE IT HIGH THROUGHPUT, BUT NOBODY HAD EVER DONE VIVAX. I HAVE TO SAY, IT WAS INCREDIBLY DIFFICULT. IT TOOK US 10 YEARS.
BUT THAT'S WHY WE CLOSE TO DO IT BECAUSE WE FELT LIKE WE REALLY COULD OPEN SOME NEW BIOLOGY DOORS THERE. >> HOW DOES -- ANOTHER QUESTION, HOW DOES THE PARASITE GET FROM THE BLOOD THROUGH THE SIGH SINUSOIDAL IF HENESS TRAL BARRIER TO THE HEPATOCYTE? >> SO THE SPORE ZOITE TRAVERSES ALONG FREU THE FENESTRATED EPITHELIUM AND IT GLIDES, THIS HAS BEEN STUDIED BY MARIA MODA AND OTHERS. IT ACTUALLY CAN BREAK THROUGH SEVERAL HEPATOCYTES BEFORE IT SETS UP SHOP IN ONE.
SO IT HAS A GLIDING MECHANISM. YOU CAN ACTUALLY SEE IT IN CULL FEWER IF YOU PUT CULTURE, IF YOU PUT A SPORE SEW IETD ON A GLASS SLIDE, IT WILL LEAVE THESE LITTLE SPIRALS. >> BUT ISN'T IT TOO BIG TO GO THROUGH THE -- >> IT IS, IT IS BIG. >> LIKE 100-NANOMETERS AT BEST.
>> THAT'S A GOOD QUESTION. SO FOR A WHILE, THERE WAS A THEORY THAT THEY WERE ACTUALLY FIRST INVADING KUFER CELLS AND THEY WERE SHEPPARDING ACROSS THE SINUSOID. I THINK THERE'S DATA ON BOTH SIDES OF THAT, AND ONLY IN RODENTS, SO I'M NOT SURE ANYONE IS CONVINCED THAT THE KUFER CELLS ARE REQUIRED.
>> DO YOU HAVE KUFER CELLS IN YOUR OPERATION? >> I DON'T. BUT I WILL SAY THAT OUR INFECTION RATES ARE VERY LOW COMPARED TO WHAT YOU EXPECT. WE KNOW THAT VERY FEW -- I MEAN, ONE PARASITE CAN CAUSE A PRODUCTIVE INFECTION, AND IN OURS, WE PUT THOUSANDS OF PARASITES IN SO THE EFFICIENCY IS MUCH LOWER. >> SO HERE'S A PROVOCATIVE QUESTION FOR YOU.
WHAT DO YOU THINK THE NEXT DEVELOPMENT IN SEMICONDUCTORS IS GOING TO BE THAT'S GOING TO INFLUENCE WORK SUCH AS WHAT YOU'RE DOING. WHERE DO YOU THINK THAT WHOLE FIELD -- I MEAN, WE'VE GOTTEN DOWN TO THE POINT NOW OF NANOMETERS, MY KNEE CHIPS. MINI CHIPS. WHAT DO YOU SEE HAPPENING NEXT HAPPENING IN THAT FIELD THAT SEEMS TO BE DRAMATICALLY MOVING ALL OVER THE WORLD? >> THAT'S A GOOD QUESTION.
I MEAN, I THINK WHAT'S INTERESTING NOW IS NOT JUST THE ADVANCEMENTS THAT WILL HELP IN HARDWARE, AND SO THE MAIN WAYS THE FIELD IS THINKING ABOUT IT IS TO MAKE THREE-DIMENSIONAL COMPUTERS, SO INSTEAD OF 2D, 3D, AND THEN ALSO QUANTUM COMPUTING, WHICH IS A COMPLETELY DIFFERENT WAY OF DOING COMPUTATION. BUT THE OTHER REALLY INTERESTING THING NOW IS THAT IT'S NOT JUST HARDWARE, IT'S ALSO WHAT COMPUTATION ENABLES US IN BIOLOGY. AND SO THAT -- I MEAN, JUST FOR EXAMPLE THE SINGLE CELL DATA, WE COULDN'T HAVE DONE THAT KIND OF ANALYSIS 10 YEARS AGO, JUST BECAUSE OF THE SHEER VOLUME OF THE DATA OR THE MACHINE LEARNING IN OUR DIAGNOSTIC SIGNATURES.
SO I THINK WHAT'S COMING NOW IN THIS CHAPTER IS MACHINE LEARNING AND ARTIFICIAL INTELLIGENCE ARE REALLY CHANGING THE WAY WE HAS HANDLE DATA AS BIOLOGISTS BECAUSE THERE'S MORE DATA THAN WE CAN COMPREHEND SO WE NEED THOSE TOOLS. >> WELL, IT WOULD BE VERY EXCITING TO SEE WHAT'S GOING TO HAPPEN IN THE NEXT YEARS TO PUSH THIS FURTHER. LISTEN, ON BEHALF OF EVERYBODY, WE WANT TO REALLY THANK YOU ENORMOUSLY, AND LOOK FORWARD TO SEEING YOU IN THE NEAR FUTURE. >> THANK YOU. >> SO THANKS AGAIN, AND WE GREATLY APPRECIATE YOU SPENDING YOUR TIME GIVING THIS COMBINED WALS DEMYSTIFYING SESSION. IT WAS SUPERB.
>> THANK YOU. IT WAS GREAT TO SPEND THE AFTERNOON WITH YOU. AS ALWAYS. 01:09:14.720,00:00:00.000 >> YES, THANK YOU, EVERYONE.
2022-04-01