The proposed research targets a HIV-1 cure strategy that attempts to increase and optimize anti-HIV cellular immune responses, which play a critical role in the control of HIV replication in the body. Due to the durability and persistence of reservoirs of HIV infected cells, combined antiretroviral treatment (ART) is insufficient in eradicating HIV-1 from the body and the patients have to remain on treatment for the rest of their lives. Achieving HIV-1 cure or remission without ART treatment will require the enhancement and persistence of effective antiviral immune responses. Most current efforts primarily focus on enhancing immunity via genetic modification of peripheral T cells while we aim at creating lifelong anti-HIV responses by modifying autologous Hematopoietic Stem/Progenitor Cells (HSPCs) with an optimized anti-HIV Chimeric Antigen Receptor (CAR) molecule. In addition, the gene therapy vector expressing this CAR molecule also contains anti-HIV genes, which protects the newly developed, vector-containing T cells from infection. We will also explore immune and gene combination therapies to improve the safety, performance, and efficacy of the CAR HSPC-based therapy. We will use the Bone marrow-Thymus-Liver (BLT) humanized mouse model, a surrogate system that recapitulates the human immune system and HIV pathogenesis, to select for the best CAR vector and best combination therapy design to maximize the in vivo functionality of CAR cells. We will evaluate our lead CAR candidates and combination therapy in SHIV+ infected, anti-retroviral drug treated non-human primates (NHPs) to best mimic the human clinical setting. Our proposed study will provide crucial insights and pave the way for investigational new drug (IND) development of numerous HSPC-based CAR immunotherapies.
