Logo image
Back
Defining cellular and molecular mechanisms driving cocaine-mediated modulation of HIV replication in human iPSC-derived CNS macrophage models
Dissertation

Defining cellular and molecular mechanisms driving cocaine-mediated modulation of HIV replication in human iPSC-derived CNS macrophage models

Oluwatofunmi Oteju
Doctor of Philosophy (Ph.D.), Drexel University
Mar 2026
DOI:
https://doi.org/10.17918/00011339
pdf
Oteju_Oluwatofunmi_20264.80 MB
PDF Embargoed Access, Embargo ends: 31 May 2027

Abstract

Neurosciences HIV Induced pluripotent stem cells Macrophages Microglia Sigma-1 Cocaine
Cocaine use disorder (CUD) is a major comorbidity in people living with HIV and is associated with worsening clinical and neurological outcomes. HIV infection of the CNS, collectively termed NeuroHIV, persists despite antiretroviral therapy (cART) and is exacerbated in individuals who use cocaine. A major barrier to defining the mechanisms underlying these interactions has been the lack of tractable, human translational models that allow mechanistic interrogation of HIV infection in CNS-resident myeloid cells. To address this, we developed a syngeneic human induced pluripotent stem cell (iPSC)-derived platform to generate parenchymal microglia-like cells (iMg) and perivascular CNS-associated macrophage-like cells (iMacs) from shared donor backgrounds. Characterization of these populations revealed intrinsic baseline inflammatory differences between iMg and iMacs, including distinct transcriptomic profiles and Toll-like receptor (TLR)-mediated NF-[kappa]B activation dynamics. iMg exhibited heightened sensitivity to TLR4 stimulation with a switch-like activation profile, whereas iMacs mounted stronger early responses to TLR2 stimulation and displayed a more constitutively primed cytokine phenotype. HIV infection studies demonstrated that iMacs were more permissive to viral replication at baseline, consistent with prior literature, however, iMg were relatively more resistant to cART-mediated suppression once infected, suggesting that microglia may represent a more persistent CNS reservoir under cART treatment. Using this platform, we then investigated cocaine-mediated modulation of HIV infection in microglia. Cocaine significantly accelerated HIV replication and increased p24 secretion and the percentage of infected cells across multiple iPSC donors. Notably, enhanced viral production persisted in the presence of ART, without expansion of the infected cell pool, indicating effects at post-entry stages of the viral lifecycle. Mechanistic studies revealed that cocaine's effects were mediated by activation of the sigma-1 receptor, an endoplasmic reticulum (ER) chaperone that cocaine binds and that regulates cellular stress signaling, rather than dopaminergic receptor pathways. Pharmacologic activation of sigma-1 recapitulated, and pharmacologic inhibition or CRISPR-mediated knockout of sigma-1 attenuated, cocaine-induced enhancement of HIV replication. Single-cell RNA sequencing revealed the involvement of the unfolded protein response in driving changes in HIV + Cocaine treated cultures. Further investigation found that cocaine activated the IRE1- XBP1 arm of the unfolded protein response (UPR), and antiviral cytokine responses were concurrently reduced in HIV + Cocaine conditions, supporting the establishment of a pro-viral, stress-adapted cellular state. Immunofluorescence analyses revealed increased sigma-1 expression in HIV-infected cultures, particularly within uninfected bystander cells exposed to both HIV and cocaine, as well as cocaine-induced redistribution of sigma-1 to the ER. Overall, these findings identify sigma-1-dependent ER stress signaling as a central mechanism linking cocaine exposure to enhanced microglial HIV replication and highlight sigma-1 as a potential therapeutic target in comorbid HIV neuropathogenesis and CUD.

Metrics

1 Record Views

Details

Logo image