Cocaine Mediated Changes in Sigma-1 Receptor Enhances HIV-Infection of Human Macrophages and iPSC-derived Microglia Independent of Dopamine

Abstract ID 96924 Poster Board 326 The neurological sequelae of HIV infection of the CNS persist in people living with HIV (PLWH) despite antiretroviral therapy. Within PLWH, stimulant use is highly comorbid, worsening clinical outcomes. Despite the prevalence of stimulant use in HIV-infected populations, the mechanism(s) by which stimulants impact HIV infection are undefined. Our data show that CNS dopamine, which is released following stimulant use, increases HIV replication in CNS myeloid cells. However, it is not clear if stimulants act only via changes in dopamine or if they have other discrete effects on HIV replication. To test this, we inoculated human primary monocyte-derived macrophages (hMDM) and human induced pluripotent stem cell-derived microglia (iMg) with HIV in the presence of dopamine, methamphetamine (Meth), or cocaine (Coc). High-content imaging and p24 AlphaLISA analysis were used to define infection dynamics, evaluating the percentage of cells infected, level of secreted p24 protein (a common proxy for productive infection), and infectivity of secreted virions. As anticipated, dopamine increased p24 secretion and % infected cells in both hMDM and iMg. Interestingly, Coc, but not Meth, also increased p24 secretion and % infected cells. Further, inhibition of dopamine receptors with Flupentixol did not attenuate the impact of Coc. This was surprising, as it indicates that these effects are separate from the interaction of Coc with the myeloid dopaminergic system. Cocaine has been shown to target sigma-1 (S1R), a chaperone protein, so we evaluated whether the effects of Cocaine on HIV replication were mediated via this protein. The effects of Coc on HIV replication were blocked by BD-1063, a sigma-1 antagonist, and PRE-084, an S1R agonist, independently increased p24 secretion. This indicates that Coc acts, at least in part, via S1R and supports the lack of a dopaminergic connection. Using high-content imaging for simultaneous examination of infected (p24+) and uninfected (p24-) cell populations within infected cultures showed that uninfected cells (p24-) had elevated S1R in response to Coc treatment. This was not seen in the infected (p24+) cells, suggesting that Coc-induced changes in S1R prior to infection may increase susceptibility to HIV. Ongoing analyses further evaluate the interactive impact of HIV and Coc on the localization and specific activity of S1R using its interaction with BiP. Future studies using mixed culture systems combining syngeneic iMicroglia or iMac with iPSC-derived neurons or astrocytes will examine the transcriptional changes and downstream proteins driving the actions of Coc in CNS myeloid cells using single-cell RNA/ATACseq. These will enable more comprehensive analyses of changes in HIV infection dynamics, inflammation, and neuronal/glial health and function in response to HIV + substances of misuse. This project was funded by the National Institutes of Drug Abuse (R01 DA057337, R61 DA058501 to PJG).