Inhibition of HIV early replication by the p53 and its downstream gene p21

Virol J. 2018 Mar 27;15(1):53. doi: 10.1186/s12985-018-0959-x.

Abstract

Background: The tumor suppressor gene p53 has been found to suppress HIV infection by various mechanisms, but the inhibition of HIV at an early stage of replication by host cell p53 and its downstream gene p21 has not been well studied.

Method: VSV-G pseudotyped HIV-1 or HIV-2 viruses with GFP or luciferase reporter gene were used to infect HCT116 p53+/+ cells, HCT116 p53-/- cells and hMDMs. The infections were detected by flow cytometry or measured by luciferase assay. Reverse transcription products were quantified by a TaqMan real time PCR. siRNA knockdown experiments were applied to study potential roles of p53 and p21 genes in their restriction to HIV infection. Western blot experiments were used to analyze changes in gene expression.

Results: The infection of HIV-1 was inhibited in HCT116 p53+/+ cells in comparison to HCT116 p53-/- cells. The fold of inhibition was largely increased when cell cycle switched from cycling to non-cycling status. Further analysis showed that both p53 and p21 expressions were upregulated in non-cycling HCT116 p53+/+ cells and HIV-1 reverse transcription was subsequently inhibited. siRNA knockdown of either p53 or p21 rescued HIV-1 reverse transcription from the inhibition in non-cycling HCT116 p53+/+ cells. It was identified that the observed restrictions by p53 and p21 were associated with the suppression of RNR2 expression and phosphorylation of SAMHD1. These observations were confirmed by using siRNA knockdown experiments. In addition, p53 also inhibited HIV-2 infection in HCT116 p53+/+ cells and siRNA knockdown of p21 increased HIV-2 infection in hMDMs. Finally the expressions of p53 and p21 were found to be induced in hMDMs shortly after HIV-1 infection.

Conclusions: The p53 and its downstream gene p21 interfere with HIV early stage of replication in non-cycling cells and hMDMs.

Keywords: Cell cycle; HIV-1; HIV-2; RNR2; Reverse transcription; SAMHD1; p21; p53.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle
  • Cells, Cultured
  • Cyclin-Dependent Kinase Inhibitor p21 / genetics
  • Cyclin-Dependent Kinase Inhibitor p21 / metabolism*
  • DNA, Complementary / biosynthesis
  • DNA, Complementary / metabolism
  • Gene Knockdown Techniques
  • HCT116 Cells
  • HIV / physiology*
  • HIV Infections / immunology*
  • HIV Infections / virology*
  • Humans
  • Macrophages / immunology*
  • Macrophages / virology
  • Phosphorylation
  • Ribonucleotide Reductases / genetics
  • SAM Domain and HD Domain-Containing Protein 1 / genetics
  • SAM Domain and HD Domain-Containing Protein 1 / metabolism
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism*
  • Up-Regulation / genetics
  • Virus Replication*

Substances

  • CDKN1A protein, human
  • Cyclin-Dependent Kinase Inhibitor p21
  • DNA, Complementary
  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • Ribonucleotide Reductases
  • ribonucleotide reductase R2 subunit
  • SAM Domain and HD Domain-Containing Protein 1
  • SAMHD1 protein, human