Developing and evaluating cell-specific lentivectors capable of selective in vivo generation of anti-HIV T cells to cure HIV

To enable sustained remission of HIV recurrence in the absence of antiretroviral therapy (ART), we aim to develop a strategy to provide people with HIV (PWH) with robust and sustained anti-HIV T cell and antibody responses. We will develop injectable cell-specific lentiviral vector (LV) technology to direct in vivo generation of T cells expressing anti-HIV chimeric antigen receptor (CAR) and/or broadly neutralizing antibody (bNAb) genes. We hypothesize that by establishing broad and sustained anti-HIV immune surveillance in vivo, reactivated latently infected cells will be rapidly eliminated before they can initiate disseminated infection together with cells newly infected by HIV produced by distal reservoirs. We developed and validated the safety and efficacy of a highly potent and broad anti-HIV duoCAR-T cell therapy that is demonstrably superior to monoCAR-T cell therapy. These duoCAR-T cells target two highly conserved independent gp120 epitopes, enabling highly effective inhibition of HIV infection, while also being extremely resistant to HIV infection and providing sufficient broad reactivity to inhibit the emergence of immune escape epitopes. Our preclinical studies demonstrating the safety and efficacy of duoCAR-T cells and their great promise to provide PWH with sustained remission after cessation of ART enabled FDA-approval, which has advanced them into clinical trials in PWH (NCT04648046). We have also developed LV capable of engineering T cells to produce therapeutic levels of bNAb in vivo. However, generating duoCAR-T cells or T cells secreting bNAbs using standard ex vivo LV transduction and reinfusion into patients requires complex logistics which greatly limits wider use, particularly in resource-poor settings with the highest incidence of HIV infection. This proposal is highly significant and very responsive to the RFA, specifically our focus on developing and evaluating innovative approaches to engineer lentiviral vectors (LV) to deliver in vivo T-cell targeted gene therapy to confer T cells with potent cellular and humoral anti-HIV activity. We propose several innovative strategies to achieve our goal which include: (1) development and optimization of novel CD3-targeted LVPs directing selective in vivo transduction of T cells to produce optimized anti-HIV duoCAR-T cells; (2) identification of the CD3- or peptide-MHC conjugate-targeted LV most capable of generating optimized anti-HIV duoCAR-T cells that potently suppress HIV infection in vitro and in vivo; and (3) development and optimization of CD3-targeted LV to selectively transduce T cells in vivo to enable them to produce bNAb. We hypothesize that administration of T cell-specific therapeutic LV will direct selective in vivo generation of duoCAR-T cells and bNAb-producing T cells capable of exerting potent and sustained anti-HIV immune surveillance, either alone or together, to provide PWH with ART-free remission. We will also examine whether novel gp120-exosomes and multifunctional cytokine complexes consisting of IL-15 and a TGFβ inhibitor or IL-7, IL-15 and IL-21 stimulate in vivo expansion of duoCAR-T cells to further augment their anti-HIV activity.