Summary HIV-infected microglia release cytokines, chemokines and viral gene products, such as gp120 and tat, that are toxic to neurons. In this proposal, we will use human induced pluripotent stem cells (iPSCs) to generate cortical and dopaminergic neurons as well as microglia, which will be cultured as organoids to model HIV-drug abuse interactions in conjunction with in-depth genomic approaches and electrophysiology. We show electrophysiological results that demonstrate that the levels of differentiation of the neurons in our organoids are comparable to in vivo and ex vivo preparations and are among the best that can be found in the scientific literature. To identify candidate host regulators of HIV expression and mediators of HIV-induced tissue damage and disease progression, we will expose microglia-containing cerebral organoids to methamphetamine (METH), a stimulant, and morphine, an opiate, which are members of two of the classes of drugs of abuse that are more prevalent among People Living with HIV/AIDS (PLWHA). Cerebral organoids will be exposed to toxic HIV products such as Tat, gp120, drugs of abuse and combination antiretroviral therapy (cART). In some experiments we will also incorporate iPSC-derived astrocytes into microglia-containing cerebral organoids to test the role of astrocytes in neuroprotection and neurodegeneration. We will carry out single-cell gene expression profiling of iPSC-derived organoids exposed to drugs of abuse, HIV products, and cART and we will employ an advanced systems biology strategy to generate testable mechanistic hypotheses on the pathogenesis of neurodegeneration and tissue damage in neuroHIV (Aim 1) and identify candidate regulators of the LTR promoter that may shed light on the regulation of latency and reactivation of the HIV provirus (Aim 2). In preliminary studies, this computational experimental approach allowed us to identify candidate drivers of gene expression changes associated with neuroHIV and neurodegenerative diseases, including Alzheimer’s disease and drug and alcohol abuse. These findings support the overarching hypothesis that dissection of the gene regulatory network of the central nervous system will pave the way for the identification of novel mechanistic hypotheses and druggable targets to improve neuropsychological functioning of PLWHA and substance abuse comorbidity.

Public Health Relevance This proposal will use cerebral organoids derived from human induced pluripotent stem cells (iPSC) to model HIV interactions with drugs of abuse and combination antiretroviral therapy (cART). We will utilize convergent state-of-the-art electrophysiology, single-cell transcriptomics and a systems biology strategy to generate new mechanistic hypotheses on neuroHIV pathogenesis, HIV interaction with drugs of abuse and cART. Ultimately, this proposal will lead to novel therapeutic concepts to improve neuropsychological functioning in people with HIV and substance abuse comorbidity.