The nerve growth factor reduces APOBEC3G synthesis and enhances HIV-1 transcription and replication in human primary macrophages

Blood. 2011 Mar 10;117(10):2944-52. doi: 10.1182/blood-2010-05-287193. Epub 2011 Jan 7.

Abstract

Macrophages infected with HIV-1 sustain viral replication for long periods of time, functioning as viral reservoirs. Therefore, recognition of factors that maintain macrophage survival and influence HIV-1 replication is critical to understanding the mechanisms that regulate the HIV-1-replicative cycle. Because HIV-1-infected macrophages release the nerve growth factor (NGF), and NGF neutralization reduces viral production, we further analyzed how this molecule affects HIV-1 replication. In the present study, we show that NGF stimulates HIV-1 replication in primary macrophages by signaling through its high-affinity receptor Tropomyosin-related Kinase A (TrKA), and with the involvement of reticular calcium, protein kinase C, extracellular signal-regulated kinase, p38 kinase, and nuclear factor-κB. NGF-induced enhancement of HIV-1 replication occurred during the late events of the HIV-1-replicative cycle, with a concomitant increase in viral transcription and production. In addition, NGF reduced the synthesis of the cellular HIV-1 restriction factor APOBEC3G and also overrode its interferon-γ-induced up-regulation, allowing the production of a well-fitted virus. Because NGF-TrKA signaling is a crucial event for macrophage survival, it is possible that NGF-induced HIV-1 replication plays a role in the maintenance of HIV-1 reservoirs. Our study may contribute to the understanding of the immunopathogenesis of HIV-1 infection and provide insights about approaches aimed at limiting viral replication in HIV-1 reservoirs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • APOBEC-3G Deaminase
  • Blotting, Western
  • Cytidine Deaminase / biosynthesis*
  • Enzyme-Linked Immunosorbent Assay
  • HIV Infections / metabolism
  • HIV-1 / physiology*
  • Humans
  • Macrophages / metabolism
  • Macrophages / virology*
  • Nerve Growth Factor / metabolism*
  • Receptor, trkA / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / physiology*
  • Transcription, Genetic*
  • Virus Replication / physiology*

Substances

  • Nerve Growth Factor
  • Receptor, trkA
  • APOBEC-3G Deaminase
  • APOBEC3G protein, human
  • Cytidine Deaminase