Aberrant Autophagy in Macrophages and Astrocytes after HIV Nef or Antiretroviral Treatment: Contribution to the Pathogenesis of HIV-associated Neurocognitive Disorders

BACKGROUND: Despite antiretroviral therapy (ART), HIV-associated neurocognitive disorders (HAND) still affect 40–70% of HIV-infected people. The pathogenesis of HAND is multi-factorial and poorly understood. Macroautophagy is a cellular self-digestion process with essential roles in defense against infection, aging, and neurodegeneration. While there are a few studies showing a link between aberrant macroautophagy and cognitive defects in HIV infection, little is known of how HIV or antiretrovirals impact macroautophagy in cells of the CNS. We studied autophagy in macrophages and astrocytes—two major CNS cell types involved in HAND pathogenesis—after treatment with HIV Nef or common ART components to characterize further the pathogenesis of HAND. METHODS: PBMC were cultured to generate monocyte-derived macrophages (MDM). MDM were treated 24 or 48 hours with 5 ng/mL Tenofovir and/or 109 ng/mL Emtricitabine and lysates collected. Primary human astrocytes were treated 24 hours with 10 ng HIV Nef or 5 ng/mL Tenofovir + 109 ng/mL emtricitabine + 14 ng/mL raltegravir (ART) and lysates collected. Lysates were analyzed by western blot for LC3-II and p62 (autophagy markers) using Image Studio. RESULTS: LC3-II levels increased 1.5-, 1.6-, and 1.7-fold in MDM treated 24 hours with Tenofovir, Emtricitabine or Truvada, respectively, and p62 level decreased 25% after 24h Truvada, relative to untreated MDM. After 48 hours Truvada, LC3-II and p62 levels decreased 30% relative to control MDM. This indicates an initial upregulation followed by rapid downregulation of autophagy in antiretroviral-treated MDM. In astrocytes treated with Nef, LC3-II, and p62 flux (degradation) increased 3-fold and 1.7-fold, respectively, indicating abnormal enhancement of autophagy. Interestingly, while ART treatment increased LC3-II flux 3-fold, p62 degradation decreased 50% relative to controls, signifying a change in autophagy that impacts LC3-II and p62 differently. CONCLUSION: Our initial study demonstrates that HIV and commonly prescribed antiretrovirals induce aberrant autophagy dynamics in macrophages and astrocytes. To our knowledge, this is the first time a change in autophagy due to ART has been described in these cells. HIV and ART may disrupt the homeostasis provided by autophagy, contributing to accelerated aging and HAND in HIV-infected people. DISCLOSURES: All authors: No reported disclosures.