Pathogenic consequences of vaginal infection with CCR5-tropic simian-human immunodeficiency virus SHIVSF162P3N

J Virol. 2012 Sep;86(17):9432-42. doi: 10.1128/JVI.00852-12. Epub 2012 Jun 27.

Abstract

We previously reported efficient transmission of the pathogenic R5 simian-human immunodeficiency virus SHIV(SF162P3N) isolate in Indian rhesus macaques by intravenous and intrarectal inoculations, with a switch to CXCR4 coreceptor usage in ∼50% of infected animals that progressed rapidly to disease. Since women continue to be disproportionately affected by HIV, we developed an animal model based on the intravaginal challenge of female rhesus monkeys with SHIV(SF162P3N) and sought to validate the utility of this model to study relevant aspects of HIV transmission and pathogenesis. The effect of viral dose on infection outcome was evaluated to determine the optimal conditions for the evaluation of HIV-1 preventive and therapeutic strategies. We found that the virus can successfully cross the vaginal mucosal surface to establish infection and induce disease with coreceptor switch, but with lower efficiencies compared to intravenous and rectal transmissions. In contrast to intrarectal infection, peak and cumulative viral load over a 1 year-infection period were significantly greater in macaques exposed intravaginally to lower rather than higher inoculum doses. Moreover, low and transient viremia was observed only in macaques that were challenged intravaginally twice within the same day with a high dose of virus, which can be seen as doubling the dose. Taken together, these results show that SHIV(SF162P3N) can successfully transmit across the genital mucosa, undergo coreceptor switch, and induce disease. However, the administered dose appears to impact SHIV(SF162P3N) vaginal infection outcome in an unexpected manner.

Publication types

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

MeSH terms

  • Animals
  • Disease Models, Animal
  • Female
  • HIV Infections / metabolism
  • HIV Infections / virology*
  • HIV-1 / genetics
  • HIV-1 / pathogenicity
  • HIV-1 / physiology
  • Humans
  • Macaca mulatta
  • Mucous Membrane / metabolism
  • Mucous Membrane / virology
  • Receptors, CCR5 / genetics
  • Receptors, CCR5 / metabolism*
  • Receptors, HIV / genetics
  • Receptors, HIV / metabolism*
  • Simian Acquired Immunodeficiency Syndrome / metabolism
  • Simian Acquired Immunodeficiency Syndrome / virology*
  • Simian Immunodeficiency Virus / genetics
  • Simian Immunodeficiency Virus / pathogenicity
  • Simian Immunodeficiency Virus / physiology*
  • Vagina / metabolism
  • Vagina / virology*
  • Viral Load
  • Viral Tropism*
  • Virulence

Substances

  • Receptors, CCR5
  • Receptors, HIV