No abstract

HIV associated neurocognitive disorders (HAND) are a group of neurological deficits that affect approximately half of people living with HIV (PLWH) despite effective antiretroviral therapy (ART). There are currently no reliable molecular biomarkers or treatments for HAND. Given the national opioid epidemic, as well as illegal and prescription use of opioid drugs among PLWH, it is critical to characterize the molecular interactions between HIV and opioids in cells of the CNS. It is also important to study the role of opioid substitution therapies in the context of HIV and CNS damage in vitro and in vivo. A major mechanism contributing to HIV neuropathogenesis is chronic, low-level inflammation in the CNS. HIV enters the brain within 4–8 days after peripheral infection and establishes CNS reservoirs, even in the context of ART, that are difficult to identify and eliminate. Infected cells, including monocytes, macrophages, and microglia, produce chemokines, cytokines, neurotoxic mediators, and viral proteins that contribute to chronic inflammation and ongoing neuronal damage. Opioids have been shown to impact these immune cells through a variety of molecular mechanisms, including opioid receptor binding and cross desensitization with chemokine receptors. The effects of opioid use on cognitive outcomes in individuals with HAND in clinical studies is variable, and thus multiple biological mechanisms are likely to contribute to the complex relationship between opioids and HIV in the CNS. In this review, we will examine what is known about both HIV and opioid mediated neuropathogenesis, and discuss key molecular processes that may be impacted by HIV and opioids in the context of neuroinflammation and CNS damage. We will also assess what is known about the effects of ART on these processes, and highlight areas of study that should be addressed in the context of ART.

The COVID-19 pandemic has caused more than three million deaths globally. The severity of the disease is characterized, in part, by a dysregulated immune response. CD16+ monocytes are innate immune cells involved in inflammatory responses to viral infections, and tissue repair, among other functions. We characterized the transcriptional changes in CD16+ monocytes from PBMC of people with COVID-19, and from healthy individuals using publicly available single cell RNA sequencing data. CD16+ monocytes from people with COVID-19 compared to those from healthy individuals expressed transcriptional changes indicative of increased cell activation, and induction of a migratory phenotype. We also analyzed COVID-19 cases based on severity of the disease and found that mild cases were characterized by upregulation of interferon response and MHC class II related genes, whereas the severe cases had dysregulated expression of mitochondrial and antigen presentation genes, and upregulated inflammatory, cell movement, and apoptotic gene signatures. These results suggest that CD16+ monocytes in people with COVID-19 contribute to a dysregulated host response characterized by decreased antigen presentation, and an elevated inflammatory response with increased monocytic infiltration into tissues. Our results show that there are transcriptomic changes in CD16+ monocytes that may impact the functions of these cells, contributing to the pathogenesis and severity of COVID-19.

HIV-specific chimeric antigen receptor–T cell (CAR T cell) therapies are candidates to functionally cure HIV infection in people with HIV (PWH) by eliminating reactivated HIV-infected cells derived from latently infected cells within the HIV reservoir. Paramount to translating such therapeutic candidates successfully into the clinic will require anti-HIV CAR T cells to localize to lymphoid tissues in the body and eliminate reactivated HIV-infected cells such as CD4 + T cells and monocytes/macrophages. Here we show that i.v. injected anti-HIV duoCAR T cells, generated using a clinical-grade anti-HIV duoCAR lentiviral vector, localized to the site of active HIV infection in the spleen of humanized mice and eliminated HIV-infected PBMCs. CyTOF analysis of preinfusion duoCAR T cells revealed an early memory phenotype composed predominantly of CCR7 + stem cell–like/central memory T cells (T SCM /T CM ) with expression of some effector-like molecules. In addition, we show that anti-HIV duoCAR T cells effectively sense and kill HIV-infected CD4 + T cells and monocytes/macrophages. Furthermore, we demonstrate efficient genetic modification of T cells from PWH on suppressive ART into anti-HIV duoCAR T cells that subsequently kill autologous PBMCs superinfected with HIV. These studies support the safety and efficacy of anti-HIV duoCAR T cell therapy in our presently open phase I/IIa clinical trial (NCT04648046).

HIV-associated neurocognitive impairment (HIV-NCI) persists in 15-40% of people with HIV (PWH) despite effective antiretroviral therapy. HIV-NCI significantly impacts quality of life, and there is currently no effective treatment for it. The development of HIV-NCI is complex and is mediated, in part, by the entry of HIV-infected mature monocytes into the central nervous system (CNS). Once in the CNS, these cells release inflammatory mediators that lead to neuroinflammation, and subsequent neuronal damage. Infected monocytes may infect other CNS cells as well as differentiate into macrophages, thus contributing to viral reservoirs and chronic neuroinflammation. Substance use disorders in PWH, including the use of methamphetamine (meth), can exacerbate HIV neuropathogenesis. We characterized the effects of meth on the transcriptional profile of HIV-infected mature monocytes using RNA-sequencing. We found that meth mediated an upregulation of gene transcripts related to viral infection, cell adhesion, cytoskeletal arrangement, and extracellular matrix remodeling. We also identified downregulation of several gene transcripts involved in pathogen recognition, antigen presentation, and oxidative phosphorylation pathways. These transcriptomic changes suggest that meth increases the infiltration of mature monocytes that have a migratory phenotype into the CNS, contributing to dysregulated inflammatory responses and viral reservoir establishment and persistence, both of which contribute to neuronal damage. Overall, our results highlight potential molecules that may be targeted for therapy to limit the effects of meth on HIV neuropathogenesis.