Development of Gamma delta CAR-T cells to target CNS HIV reservoir

项目总结

PROJECT SUMMARY HIV persistence in reservoir tissues remains a major barrier to achieving a therapeutic cure despite effective antiretroviral therapy (ART). Eradicating HIV-infected cells in the central nervous system (CNS) is particularly challenging since it is a site of immune privilege and is poorly accessible to ART drugs. While cognitive impairment among people living with HIV has significantly reduced in the era of modern HIV treatment, about 30% of ART-suppressed HIV patients still display conditions of HIV-associated neurocognitive disorder (HAND), suggesting that even low levels of HIV persisting in the brain can cause neurological damage. Thus, functional cure strategies that can safely eradicate replicating virus the CNS reservoir are urgently needed. Emerging evidence suggests that myeloid cells, including brain macrophages (Mf), are sanctuaries of HIV persistence in the CNS, and that HIV-infected macrophages are more resistant to CTLs than CD4 T cells. The goal of this project is to develop a universal gamma delta (γδ) CAR-T platform with dual HIVenv/Mf-targeting for HIV- infected myeloid cells in the CNS reservoir. Our central hypothesis is that adding Mf specific CAR to anti-HIV γδ CAR-T cells will enable efficient targeting of HIV-infected cells in the CNS reservoir. Our data in rhesus macaques show enhanced in vitro killing of HIV-infected monocytic cells by γδ CD4-CAR-T cells and greater Granzyme B cytotoxicity, which has been shown to be critical for CTL killing of HIV-infected primary macrophages. Based on the unique functional properties of γδ T cells, including (i) well-documented CTL activity in immunotherapy of cancer, (ii) ability to migrate to sites of neuroinflammation, and (iii) innate anti-HIV/SIV CTL functions; we hypothesize that the dual γδ CAR-T cells will induce more effective targeting of myeloid HIV reservoirs. In Aim 1, we will develop approaches for generating retroviral and lentiviral vector-based γδ CD4- CAR-T cells toward enhanced targeting of SHIV-infected primary Mf and microglial cells. In Aim 2, we will test the in vivo potential of the optimized γδ CAR-T cell to migrate and engraft in the CNS during viremic infection with the novel macrophage-tropic TF SHIV.D model of CNS pathogenesis. The proposed research is significant because its successful completion will lead to the development of a universal γδ CAR-T cell model with enhanced targeting of tissue macrophage reservoirs including the CNS in a clinically relevant model of SHIV.D infected rhesus macaques.