PROJECT SUMMARY Systemic immune activation in people living with HIV has been hypothesized to account for higher incidence of chronic inflammatory diseases, including HIV-associated neurocognitive disorders (HAND). Acute HIV infection in the CNS is thought to initiate a cascade of pro-inflammatory events that result in inflammation-induced neuronal injury and associated neurocognitive disorders that are evident even in the present combination antiretroviral therapy (cART) era. The use of psychostimulants (such as cocaine and methamphetamine) and alcohol has been shown to disrupt BBB integrity. Disrupted BBB may increase immune cell infiltrating into the CNS and promote glial activation, increased inflammation and neurotoxicity. Interestingly, increased permeability of BBB has been implicated in the progression of HIV neurological dysfunction. Thus, the combined effect of cocaine usage and HIV infection can cause an additive effect on BBB disruption and further impact HIV-related neurocognitive impairments. However, not much genome-wide molecular level study has been done in understanding BBB integrity in substance use disorder and in HIV infection/HAND. The proposed study will address this important question. Our central hypothesis is that cocaine misuse exacerbates HIV pathogenesis in the CNS by disrupting blood-brain barrier and dysregulating the glial population in the brain. Our overall objective is to exploit cell type specific transcriptomic information at the single nuclei level from patient brain samples to characterize the effects of cocaine use disorder on CNS neuronal and glial cells, HIV infection and HANDs. We will characterize single nuclei gene expression and identify dysregulated gene regulatory networks in each of the neuronal and glial populations associated with cocaine misuse in HIV infected individuals and/or with HANDs. We will also perform computational analysis to identify neuronal and glial cell regulatory networks altered by cocaine misuse. In the validation and functional characterization component, we will characterize top genes in 3D brain organoid model and will characterize with CRISPR knockout and overexpression of the gene. Successful completion of these aims will have significant research and clinical impact by 1) elucidating how cocaine misuse alters HIV/HAND pathogenesis in the CNS, and 2) discovering candidate molecules to regulate HIV infection or persistence in the CNS in the context of cocaine misuse.

PROJECT NARRATIVE This project will dissect the dysregulated molecular circuitry in the brains of individuals with cocaine use disorder and/or HIV infection. The proposal will identify genes in human brain that contribute to cocaine use disorder and HIV-related neurocognitive impairments. These approaches could lead to novel gene therapies to control and perhaps reverse the relentless disease state.