Red/Green Astrocytes Mimic CNS Viral Reservoirs in Post ART HAND: Implications for Meth Abuse

Hypothesis: Though anti-retroviral therapy (ART) has increased the life expectancy of HIV-1 infected individuals, the quest for eradication of latent viral reservoirs continues. Methamphetamine (Meth) abuse and HIV-1 infection increase neuroinflammation through cellular and molecular mechanisms such as gliosis, viral replication, oxidative stress, and excitotoxicity. Multiple studies have validated astrocytes as a major reservoir of HIV-1 in the CNS. We hypothesized that astrocyte HIV-1 reservoirs contribute to HIV-associated neurocognitive disorders (HAND) pathogenesis, and are mediated by Meth abuse during HIV-1 infection. Materials and Methods: A doubly labeled fluorescent reporter Red/Green-HIV-1 (R/G-HIV-1) was used to model latency in primary human astrocytes. Active (mCherry+/GFP+) and latently infected (mCherry+/GFP-) astrocytes were enriched using fluorescence activated cell sorting. Results: Pseudotyped R/G-HIV-1-infected astrocytes established latency over a period of 21 days. These studies were also conducted with pre- and/or post-Meth treatment. Latently-infected astrocytes were devoid of late viral proteins such as p24, indicating a functionally silent HIV-1 LTR. Vorinostat, an HDAC inhibitor, reactivated the silenced HIV-1 LTR in a mixed population of pseudotyped R/G-HIV-1-infected astrocytes. Conclusions: Our data suggests R/G-HIV-1 could be used as a relevant model of latency in astrocytes since it mimics virus reactivation in inflammation leading to viral proteins expression. We anticipate that healthy versus latently infected astrocytes respond differentially to inflammation. Investigating the underlying mechanisms will help in assessing the role of HIV-1 astrocyte reservoirs in HAND pathogenesis.