Project Grant R21AI181743

IN VIVO CAR-T-CELL HIV THERAPY USING IN VITRO RECONSTITUTED VIRUS-LIKE PARTICLES - PROJECT SUMMARY/ABSTRACT "KILLER" ("CYTOTOXIC") T CELLS ARE THE CELLS OF THE IMMUNE SYSTEM THAT HAVE THE JOB OF KILLING CANCEROUS AND VIRUS-INFECTED CELLS. BUT THEY DO SO ONLY IF THEY HAVE RECEPTORS CAPABLE OF RECOGNIZING ANTIGENS - EXPRESSED ON THE SURFACE OF TARGET CELLS - THAT ARE SPECIFIC TO THE CANCER OR VIRUS INVOLVED. AND OFTEN IT IS THE ABSENCE OR SHORTAGE OF THESE ANTIGEN-SPECIFIC RECEPTORS THAT IS RESPONSIBLE FOR A PATIENT NOT SURVIVING THE GROWTH AND METASTASIS OF A CANCER OR THE SPREAD OF A VIRAL INFECTION. ACCORDINGLY, IMMUNOTHERAPIES HAVE BEEN DEVELOPED THAT INVOLVE: EXTRACTING T CELLS FROM A PATIENT; TRANSFORMING THEM SO THAT THEY EXPRESS THE DESIRED RECEPTORS; "EXPANDING" ("GROWING UP") THE CELLS; AND, FINALLY, PUTTING THEM BACK INTO THE PATIENT SO THAT THEY CAN LOWER THE LOAD OF CANCEROUS OR VIRUS-INFECTED TISSUE. ASIDE FROM THE COST AND DANGER OF EXTRACTION AND INFUSION OF IMMUNE CELLS, THIS EX VIVO PROCEDURE - THE CURRENT STATE-OF-THE-ART OF IMMUNOTHERAPY - INTRODUCES SERIOUS RISK OF ONCOGENESIS BECAUSE THE T-CELL TRANSFORMATION INVOLVES THE (POORLY- CONTROLLED) INTEGRATION OF RECEPTOR GENES INTO THE T-CELL CHROMOSOMES. WHAT WE ARE PROPOSING IS A TOTALLY DIFFERENT APPROACH THAT AVOIDS THE RISKS OF BOTH THE EXTRACTION/INFUSION AND OF THE CHROMOSOMAL TRANSFORMATION. MORE EXPLICITLY, OUR AIM IS TO TRANSFORM T CELLS IN VIVO, BY DELIVERING THE RECEPTOR GENES DIRECTLY TO THE T CELLS IN THE BLOOD AND LYMPH SYSTEM OF THE PATIENT; FURTHER, THE GENES ARE IN MRNA FORM SO THAT THEIR EXPRESSION IS TRANSIENT, INVOLVING NO CHANGE IN CHROMOSOMAL DNA; FINALLY, THE MRNA IS PROTECTED AND TARGETED BY BEING SELF-ASSEMBLED IN VITRO WITH PURIFIED VIRAL CAPSID PROTEIN, SO THAT ITS SHELL IS FUNCTIONALIZED WITH AN ANTIBODY AGAINST PROTEINS UNIQUELY EXPRESSED IN T CELLS. OUR METHODOLOGY INVOLVES THE COMPLEMENTARY EXPERTISES OF THE TWO PIS. DR.GELBART'S LAB HAS WORKED FOR THE PAST 15 YEARS ON THE IN VITRO PACKAGING OF MRNA INTO VIRUS-LIKE PARTICLES (VLPS) USING THE CAPSID PROTEIN OF A PLANT VIRUS THAT IS CAPABLE OF SELF-ASSEMBLING AROUND ARBITRARY- SEQUENCE RNA, AND ON THE FUNCTIONALIZATION OF THESE PARTICLES WITH TARGETING ANTIBODIES AND OTHER PROTEIN LIGANDS. DR. YANG'S LAB HAS WORKED FOR THE PAST 25 YEARS ON THE BASIC BIOLOGY OF HIV INFECTIONS AND SPECIFICALLY ON THE EX VIVO TRANSFORMATION OF T CELLS WITH T-CELL RECEPTORS (TCRS) AND/OR CHIMERIC ANTIGEN RECEPTORS (CARS) THAT ARE SPECIFIC AGAINST HIV OR CANCER ANTIGENS AND ON QUANTIFYING THE CELL-KILLING ACTIVITY OF THESE TRANSFORMED T CELLS. TOGETHER WE WILL BE DEVELOPING AN IN VIVO T-CELL THERAPY ALONG THE LINES OUTLINED ABOVE AND DEMONSTRATING ITS EFFICACY IN A MOUSE MODEL OF HIV.