In vivo cell engineering for HIV cure. - ABSTRACT Many innovative gene and cell therapy strategies are being considered for an HIV cure. However, for a cure to be acceptable to people living with HIV (PLWH), it must not only be effective, but also have a favorable profile of safety/toxicity, cost, practicality and accessibility. In this Program Project we are focused on developing an HIV cure that would be acceptable to PLWH, with a path towards greater accessibility, including for low and middle-income countries. To do this, we are taking advantage of significant recent innovations in gene and cell therapy technologies, which have included contributions from the members of this team. Specifically: (1) new gene therapy vector formulations and gene editing tools that support targeted in vivo editing to precisely modify hematopoietic stem cells (HSCs), T cells and B cells; (2) surface accessible bone marrow cryogel ports that further facilitate in vivo cell engineering, and which can also direct the differentiation of engineered cells; (3) chemotherapy-free conditioning regimens based on epitope editing that allow both selection of engineered cells and a reduction in the HIV reservoir; and (4) a portfolio of broadly-acting and validated anti-HIV reagents that can be used in combination to control HIV. To do this, we have assembled a multi-PI academic team with long- standing collaborations and who are innovators in these areas. The three interacting projects, Project 1/Kiem, Project 2/Cannon and Project 3/Scadden, will be supported by an Administrative Core and a Nonhuman Primate Core that brings extensive expertise in the evaluation of gene and cell therapies in SHIV-infected rhesus macaques. We are also supported by a network of industry partners who will contribute intellectually and provide expertise and reagents in key technologies and will facilitate the translational development of our approaches. The project will be organized with the following 4 Overall Specific Aims: Overall Aim 1. Identify an optimal strategy to select for engineered HSC and also deplete the HIV reservoir. Overall Aim 2. Identify the best vector approaches for in vivo engineering of HSC and B cells. Overall Aim 3. Evaluate the use of a novel organoid for in situ delivery of anti-HIV vectors. Overall Aim 4. Identify the best combination of anti-HIV approaches, based on CCR5 knockout, expression of broadly acting HIV inhibitors and direct targeting of the integrated provirus.