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

PLoS One. 2019 Nov 27;14(11):e0225760. doi: 10.1371/journal.pone.0225760. eCollection 2019.

Abstract

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / metabolism
  • Astrocytes / transplantation*
  • Blood-Brain Barrier / metabolism
  • Blood-Brain Barrier / pathology*
  • Cells, Cultured
  • Hippocampus / metabolism
  • Hippocampus / pathology*
  • Interleukin-1beta / metabolism
  • Lung Diseases, Interstitial / etiology*
  • Lung Diseases, Interstitial / pathology
  • Macrophages / metabolism
  • Macrophages / pathology
  • Male
  • Neurons / metabolism
  • Neurons / pathology*
  • Rats
  • Rats, Sprague-Dawley
  • nef Gene Products, Human Immunodeficiency Virus / genetics
  • nef Gene Products, Human Immunodeficiency Virus / metabolism*

Substances

  • IL1B protein, rat
  • Interleukin-1beta
  • nef Gene Products, Human Immunodeficiency Virus
  • nef protein, Human immunodeficiency virus 1