Central Nervous System (CNS) Viral Seeding by Mature Monocytes and Potential Therapies To Reduce CNS Viral Reservoirs in the cART Era

Abstract

The human immunodeficiency virus (HIV) enters the central nervous system (CNS) within a few days after primary infection, establishing viral reservoirs that persist even with combined antiretroviral therapy (cART). We show that monocytes from people living with HIV (PLWH) on suppressive cART harboring integrated HIV, viral mRNA, and/or viral proteins preferentially transmigrate across the blood-brain barrier (BBB) to CCL2 and are significantly enriched post-transmigration, and even more highly enriched posttransmigration than T cells with similar properties. Using HIV-infected ART-treated mature monocytes cultured in vitro, we recapitulate these findings and demonstrate that HIV+ CD14+ CD16+ ART-treated monocytes also preferentially transmigrate. Cenicriviroc and anti-JAM-A and anti-ALCAM antibodies significantly and preferentially reduce/block transmigration of HIV+ CD14+ CD16+ ART-treated monocytes. These findings highlight the importance of monocytes in CNS HIV reservoirs and suggest targets to eliminate their formation and reseeding. IMPORTANCE We characterized mechanisms of CNS viral reservoir establishment/replenishment using peripheral blood mononuclear cells (PBMC) of PLWH on cART and propose therapeutic targets to reduce/block selective entry of cells harboring HIV (HIV+) into the CNS. Using DNA/RNAscope, we show that CD14+ CD16+ monocytes with integrated HIV, transcriptionally active, and/or with active viral replication from PBMC of PLWH prescribed cART and virally suppressed, selectively transmigrate across a human BBB model. This is the first study to our knowledge demonstrating that monocytes from PLWH with HIV disease for approximately 22 years and with long-term documented suppression can still carry virus into the CNS that has potential to be reactivated and infectious. This selective entry into the CNS—and likely other tissues—indicates a mechanism of reservoir formation/reseeding in the cART era. Using blocking studies, we propose CCR2, JAM-A, and ALCAM as targets on HIV+ CD14+ CD16+ monocytes to reduce and/or prevent CNS reservoir replenishment and to treat HAND and other HIV-associated comorbidities.

Compartmentalization of cerebrospinal fluid inflammation across the spectrum of untreated HIV-1 infection, central nervous system injury and viral suppression

“…CSF NfL also exhibited this strong linear trend, and these two macrophage biomarkers were among those that correlated well with CSF NfL, along with CSF sCD14 and sVCAM-1. These associations are consistent with the prevalent hypothesis that HIV-1-related neuronal injury is associated with macrophage recruitment into and activation within the CNS [ 31 , 88 , 89 ]. If elevation of these monocyte-associated biomarkers is involved in ‘low-inflammatory’ CNS injury, this begins to increase in frequency when CD4+ cells fall below 200 per μL, Myeloid cells are important in supporting recruitment and replication of M-tropic HIV-1 within the CNS [ 90 – 93 ] and in generation of neuropathogenic signals and toxins [ 60 ].…”

“…CSF NfL also exhibited this strong linear trend, and these two macrophage biomarkers were among those that correlated well with CSF NfL, along with CSF sCD14 and sVCAM-1. These associations are consistent with the prevalent hypothesis that HIV-1-related neuronal injury is associated with macrophage recruitment into and activation within the CNS [31,88,89]. If elevation of these monocyte-associated The panels graph group values for each of the Inflammatory biomarkers in CSF and blood after the subjects were regrouped on the basis of blood CD4+ T cell counts, CSF NfL and HAD diagnosis as described in the text.…”

HIV Increases the Inhibitory Impact of Morphine and Antiretrovirals on Autophagy in Primary Human Macrophages: Contributions to Neuropathogenesis

“…Uninfected MDM were untreated (Untx) or treated with 100 nM morphine (Sigma-Aldrich, St. Louis, MO, USA), an ART cocktail consisting of 15 μM tenofovir, 15 μM emtricitabine, and 1 μM raltegravir, or both morphine+ART, for 24 h. All three ART drugs were used in their free base forms. Tenofovir and emtricitabine concentrations are consistent with prior studies in primary human macrophages and monocytes [ 36 , 37 , 38 , 39 ]. The concentration of raltegravir used is consistent with studies that tested integrase inhibitors in myeloid cells, and it is within the range detectable in serum [ 40 , 41 ].…”

The Roles of Junctional Adhesion Molecules (JAMs) in Cell Migration

“…Except for those functions of metalloproteinase in the previous content, Williams et al found that CD14 + CD16 + monocytes selectively transmigrated across the BBB model due to increased JAM-A and ALCAM expression in HIV-infected individuals ( Williams et al, 2013 ; Williams et al, 2015 ). HIV+ CD14 + CD16 + ART-treated monocytes (mature monocytes infected with HIV and treated with ART) preferentially transmigrate across the BBB to CCL2, which was reduced and/or blocked by blocking antibodies against junctional proteins JAM-A significantly ( León-Rivera et al, 2021 ). In addition, buprenorphine limits the chemokine (C–C motif) ligand 2 (CCL2)-mediated monocyte transmigration into the central nervous system (CNS), through decreasing the phosphorylation of the junctional protein JAM-A increase ( Carvallo et al, 2015 ).…”