HIV-associated distal sensory polyneuropathy (HIV-DSP) remains prevalent even in the antiretroviral therapy (ART) era. Previously, we identified the upregulation of nociceptive ion channels transient receptor potential vanilloid 1 (TRPV1) and ankyrin 1 (TRPA1) in the dorsal root ganglia (DRG) of simian immunodeficiency virus (SIV)-infected ART-treated macaques. To investigate upstream mechanisms, we performed bulk RNA-seq and pathway analysis on DRGs from uninfected, SIV-infected, and SIV-infected/ART macaques. SIV infection drove strong activation of upstream regulators of interferon γ (IFNγ) and lipopolysaccharide (LPS). Although ART reduced overall IFNγ and LPS pathway activity, the IFNγ-inducible chemokines C-X-C motif chemokine ligand (CXCL)9 and CXCL10 remained significantly upregulated. To determine whether these chemokines influence TRPV1/TRPA1 expression, we treated induced pluripotent stem cell-derived peripheral sensory neurons (iPSC-PSNs) with CXCL9 and CXCL10, which induced a significant increase in TRPV1 but not TRPA1 expression. In parallel experiments, IFNγ but not LPS stimulated monocyte-derived macrophages (MDMs) to release CXCL9 and CXCL10. Conditioned media from IFNγ-treated MDMs modestly increased TRPV1 expression in iPSC-PSNs, and pharmacological inhibition of CXCR3, the receptor of CXCL9/10, did not reduce this effect. Together, these data indicate that persistent IFNγ-driven CXCL9/10 signaling may be one contributor to nociceptor sensitization underlying HIV-DSP, even in the presence of ART.
Although neurological disease is common in people with human immunodeficiency virus (HIV) (PWH), the contributing factors and underlying inflammatory mechanisms remain challenging to identify. Extracellular vesicles (EVs) constitute a relatively uncharacterized modality of intercellular communication and bioactive cargo transport in the setting of viral infection and pathogenesis. EVs carry inflammatory mediators to areas of the periphery during antiretroviral therapy (ART) suppression but are understudied in the brain. Using a biologically relevant simian–human immunodeficiency chimeric virus with a clade D HIV envelope (SHIV.D)-infected rhesus macaque (RM) model of HIV persistence in the central nervous system (CNS), we investigate circulating EV populations and the protein cargo of myeloid-derived EVs during SHIV infection. Using EV flow cytometry to quantify specific EV subpopulations, we found a significant increase in TMEM119+ microglial EVs and CD171+ neuronal EVs in RM plasma during viremia and ART suppression. Using primary RM monocyte-derived macrophages (MDMs), we determined that MDMs increased EV production after SHIV infection. Whole proteomic analysis of these EVs demonstrated that myeloid EVs isolated from SHIV.D-infected MDMs carried significantly increased levels of neuropathogenic and inflammatory proteins. Altogether, these studies improve our understanding of the contribution of myeloid EVs to neurological disease during SHIV/HIV infection.