Evaluating the Role of Viral Proteins in HIV-Mediated Neurotoxicity Using Primary Human Neuronal Cultures

Infusion of HIV-1 Nef-expressing astrocytes into the rat hippocampus induces enteropathy and interstitial pneumonitis and increases blood-brain-barrier permeability

Even though HIV-1 replication can be suppressed by combination antiretroviral therapy (cART) inflammatory processes still occur, contributing to comorbidities. Comorbidities are attributed to variety of factors, including HIV-1 mediated inflammation. Several HIV-1 proteins mediate central nervous system (CNS) inflammation, including Nef. Nef is an early HIV-1 protein, toxic to neurons and glia and is sufficient to cause learning impairment similar to some deficits observed in HIV-1 associated neurocognitive disorders. To determine whether hippocampal Nef expression by astrocytes contributes to comorbidities, specifically peripheral inflammation, we infused Sprague Dawley rats with GFP- (control) or Nef-transfected astrocytes into the right hippocampus. Brain, lung, and ileum were collected postmortem for the measurement of inflammatory markers. Increased blood-brain-barrier permeability and serum IL-1β levels were detected in the Nef-treated rats. The lungs of Nef-treated rats demonstrated leukocyte infiltration, macrophage upregulation, and enhanced vascular permeability. Ileal tissue showed reactive follicular lymphoid hyperplasia, increased permeability and macrophage infiltration. The intracerebroventricular application of IL-1 receptor antagonist reduced infiltration of immune cells into ileum and lung, indicating the important role of IL-1β in mediating the spread of inflammation from the brain to other tissues. This suggests that localized expression of a single viral protein, HIV-1 Nef, can contribute to a broader inflammatory response by upregulation of IL-1β. Further, these results suggest that Nef contributes to the chronic inflammation seen in HIV patients, even in those whose viremia is controlled by cART.

Identification, Localization, and Quantification of HIV Reservoirs Using Microscopy

The major barrier to eradicating human immunodeficiency virus-1 (HIV) infection is the generation and extended survival of HIV reservoirs. In order to eradicate HIV infection, it is essential to detect, quantify, and characterize circulating and tissue-associated viral reservoirs in infected individuals. Currently, PCR-based technologies and Quantitative Viral Outgrowth Assays (Q-VOA) are the gold standards to detect viral reservoirs. However, these methods are limited to detecting circulating viral reservoirs, and it has been shown that they misrepresent the size of the reservoirs, largely because they detect only one component of the HIV life cycle and are unable to detect viral reservoirs in tissues. Here, we described the use of multiple detection systems to identify integrated HIV DNA or viral mRNA and several HIV proteins in circulating and tissue reservoirs using improved staining and microscopy techniques. We believe that this imaging-based approach for detecting HIV reservoirs will lead to breakthroughs necessary to eradicate these reservoirs. © 2018 by John Wiley & Sons, Inc.

4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol} (TIMBD) suppresses HIV1-gp120 mediated production of IL6 and IL8 but not CCL5

Human immunodeficiency virus (HIV) has been associated with inflammatory effects that may potentially result in neurodegenerative changes and a number of newer chemotherapeutic agents are being tested to ameliorate these effects. In this study, we investigated the anti-neuroinflammatory activity of a novel resveratrol analog 4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol} (TIMBD) against HIV1-gp120 induced neuroinflammation in SVG astrocytes. SVG astrocytic cells were pretreated with TIMBD or resveratrol (RES) and then transfected with a plasmid encoding HIV1-gp120. The mRNA and protein expression levels of proinflammatory cytokines IL6, IL8 and CCL5 were determined. Protein expression levels of NF-κB, AP1, p-STAT3, p-AKT, p-IKKs and p-p38 MAPK were also determined. TIMBD inhibited gp120-induced RNA and protein expression levels of IL6 and IL8, but not that of CCL5 in SVG astrocytes. Moreover, TIMBD attenuated gp120-induced phosphorylation of cJUN, cFOS, STAT3, p38-MAPK, AKT and IKKs, and the nuclear translocation of NF-κB p-65 subunit whereas RES mostly affected NF-κB protein expression levels. Our results suggest that TIMBD exerts anti-inflammatory effects better than that of RES in SVG astrocytes in vitro. These effects seem to be regulated by AP1, STAT-3 and NF-κB signaling pathways. TIMBD may thus have a potential of being a novel agent for treating HIV1-gp120-mediated neuroinflammatory diseases.