Engineering CAR T cells to Provide a Durable Control of HIV Replication

Project 3 seeks to improve upon a Dual CAR T cell (CART) design that uses two CD4-based CARs in a single T cell in which one is linked to the 4-1BB costimulation domain and the other is linked CD28 costimulation domain. These Dual CARTs are protected from HIV infection by linking the expression of C34-CXCR4 to CAR expression. This CART is being tested in ACTG 5419 and goal of this project is to improve upon this design so it can be tested in subsequent Phase I clinical trial. In Aim 1, we seek to improve the sensitivity by which the Dual CARTs recognize Env by testing an array of scFv-based CARs and improving its function by augmenting the Dual CARTs endocytic rate in order to maximize CAR expression. In Aim 2, we seek to develop strategies that will promote Dual CART persistence in the absence of antigen, test a Dual CAR concept that could cure both leukemia and HIV at the same time, and perform a series of humanized mouse studies that will allow us to identify a single optimal Dual CART design that controls HIV replication the best. Aim 3 performs an NHP cure study in which the current Dual CART design is directly compared to the new Dual CART design. In summary, Project 3 will perform preclinical studies focused on generating engineered T cells best suited to aid HIV Cure efforts. We will evaluate strategies that increase the sensitivity, function, resistance to infection, and persistence of HIV-specific CART. Project Integration: Project 3 will work closely with Project 1 to both identify and translate these approaches from a well validated LCMV model to HIV-focused studies. Project 2 and Project 3 will work together to better understand the relationship between CART trafficking and reservoir clearance. Project 3 and Project 4 will collaborate on CART design and manufacturing as well as efforts to validate the success of HIV cure strategies in non-human primates (NHPs). Project 3 will use the expertise housed in Core B to optimally engineer HIV-specific T cells and take advantage of the expertise and infrastructure in Core C to use state of the art NHP models of HIV cure to rigorously assess the clinical significance of identified strategies.