Extracellular Vesicle Activation of Latent HIV-1 Is Driven by EV-Associated c-Src and Cellular SRC-1 via the PI3K/AKT/mTOR Pathway

Viruses. 2020 Jun 19;12(6):665. doi: 10.3390/v12060665.

Abstract

HIV-1 is a global health crisis that has infected more than 37 million people. Latent reservoirs throughout the body are a major hurdle when it comes to eradicating the virus. In our previous study, we found that exosomes, a type of extracellular vesicle (EV), from uninfected cells activate the transcription of HIV-1 in latent infected cells, regardless of combination antiretroviral therapy (cART). In this study, we investigated the specific mechanism behind the EV activation of latent HIV-1. We found that phosphorylated c-Src is present in EVs of various cell lines and has the ability to activate downstream proteins such as EGFR, initiating a signal cascade. EGFR is then able to activate the PI3K/AKT/mTOR pathway, resulting in the activation of STAT3 and SRC-1, culminating in the reversal of HIV-1 latency. This was verified by examining levels of HIV-1 TAR, genomic RNA and HIV-1 Gag p24 protein in cell lines and primary cells. We found that EVs containing c-Src rescued HIV-1 despite the presence of inhibitors, validating the importance of EV-associated c-Src in latent HIV-1 activation. Lastly, we discovered an increased recruitment of p300 and NF-κB in the nucleus of EV-treated infected cells. Collectively, our data suggest that EV-associated c-Src is able to activate latent HIV-1 via the PI3K/AKT/mTOR pathway and SRC-1/p300-driven chromatin remodeling. These findings could aid in designing new strategies to prevent the reactivation of latent HIV-1 in patients under cART.

Keywords: HIV-1; PI3/AKT/mTOR pathway; SRC-1; c-Src; extracellular vesicle.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Cell Line, Tumor
  • E1A-Associated p300 Protein / metabolism
  • ErbB Receptors / metabolism
  • Exosomes / metabolism*
  • Extracellular Vesicles / metabolism
  • HIV Core Protein p24 / metabolism
  • HIV Infections
  • HIV-1 / growth & development*
  • Humans
  • Jurkat Cells
  • NF-kappa B / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism
  • Proto-Oncogene Proteins pp60(c-src) / metabolism*
  • RNA-Binding Proteins / metabolism
  • STAT3 Transcription Factor / metabolism
  • TOR Serine-Threonine Kinases / metabolism
  • Transcription, Genetic / genetics
  • Transcriptional Activation / genetics
  • U937 Cells
  • Virus Activation / physiology*
  • Virus Latency / physiology*

Substances

  • HIV Core Protein p24
  • NF-kappa B
  • RNA-Binding Proteins
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • p24 protein, Human Immunodeficiency Virus Type 1
  • E1A-Associated p300 Protein
  • EP300 protein, human
  • MTOR protein, human
  • TOR Serine-Threonine Kinases
  • EGFR protein, human
  • ErbB Receptors
  • Proto-Oncogene Proteins pp60(c-src)
  • Proto-Oncogene Proteins c-akt