Opioid-induced transcriptional reprogramming of cerebrospinal fluid immune cells is associated with neuroinflammatory signaling in antiretroviral treated SIV-infected rhesus macaques.

backgroundOpioid use is disproportionately high among People with HIV (PWH). Although combined antiretroviral therapy (ART) can dampen HIV-associated dementia, a large fraction of PWH continue to experience neurocognitive deficits which are further exacerbated by opioid use. In the present study, we performed single cell RNA sequencing (scRNA-seq) of cerebrospinal fluid (CSF) immune cells to explore how opioid mediated transcriptomic alterations impact neuroinflammatory signaling among PWH using the SIV/rhesus macaque model.

methodsHerein, we utilized CSF cells from morphine- and saline-administered, SIV-infected, ART-treated rhesus macaques (RMs). The CSF scRNA-seq was performed longitudinally at baseline, post ramp-up with morphine (pre-infection), during acute infection, and after suppression of viremia to profile cell-specific transcriptomic signatures that mirror the CNS pathogenesis observed in opioid-dependent PWH.

resultsWe observed all major immune cells in CSF, including CD4 + TCM cells, CD4 + TEM cells, CD8+ naïve T cells, CD8 + TCM cells, CD8 + TEM cells, CD14 + Monocytes, CD16 + Monocytes, NK cells, and B cells. Additionally, we found that morphine-mediated relative increase in CD4 + TCM, Treg, and a reduction in CD8 + TEM cell population prior to SIV infection. Chronic use of morphine was associated with a Th1/Th2 T-cell imbalance with a dominance of the Th2 population. In CSF cells from morphine-dependent RMs, there was dysregulation of genes involved in T-cell receptor signaling pathways, apoptosis, PI3K-Akt signaling pathway, cellular senescence, oxidative phosphorylation, and multiple neurodegenerative disorders. The contribution of different cell populations in these processes evolved across disease stages. During the chronic stage of the disease, the expression of disease-associated microglia (DAM) signature genes were significantly up or down regulated in monocytes. Further, cell-cell receptor-ligand interaction analysis revealed altered number of intercellular interactions and signaling strength in morphine vs. saline-administered animals. Specifically, for the CD14 + monocyte populations, the intra/inter-cell communication involving ligand-receptor pairs, including APOE-TREM2, APP (TREM2 + TYROBP), APP-CD74, SPP1−(ITGA4 + ITGB1), and CCL signaling pathways, remains significantly altered in the morphine-dependent macaques.

conclusionChronic opioid exposure reprograms CSF immune cells, creating a Th1/Th2 T-cell imbalance and polarizing monocytes toward a DAM-like state. This cell type specific transcriptomic signature is associated with progressive neuroinflammatory signaling in morphine-dependent macaques, and may have implications for neuroinflammatory and neurodegenerative phenotypes observed in PWH.