Progestin-based contraceptive suppresses cellular immune responses in SHIV-infected rhesus macaques

Virology. 2006 Aug 15;352(1):169-77. doi: 10.1016/j.virol.2006.04.004. Epub 2006 May 30.


Nine rhesus macaques in groups of three received a single dose of the injectable progestin-based contraceptive Depo-Provera 5 weeks prior to challenge intravaginally with varying doses of a mixture of the pathogenic CXCR4 (X4)-SHIV(SF33A) and CCR5 (R5)-SHIV(SF162P3) isolates. As controls, seven Depo-naive animals were inoculated once with a high-dose of the mixed inoculum. Irrespective of inoculum dose, acute viremia was higher in the Depo-treated than in the Depo-naive animals. Further, genetic complexity of the replicating virus was greater and replication of the X4 virus was favored in dually infected animals treated with Depo-Provera. Analysis of cellular immune responses revealed slower response rates in virus-specific IFN-gamma production to SIV Gag in the Depo-treated macaques. The immunosuppressive effect of Depo-Provera on mounting an antiviral cellular immune response may account for the increase viral burden and diversity, and the predominance of X4 virus replication in SHIV infected macaques that were administered the progestin-based contraceptive.

Publication types

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

MeSH terms

  • Animals
  • Contraceptive Agents, Female / administration & dosage
  • Contraceptive Agents, Female / pharmacology
  • Disease Susceptibility
  • Female
  • HIV Infections / drug therapy
  • HIV Infections / immunology
  • HIV Infections / virology
  • HIV-1 / immunology
  • HIV-1 / pathogenicity*
  • Humans
  • Interferon-gamma / biosynthesis
  • Lymphocyte Activation / drug effects*
  • Macaca mulatta
  • Medroxyprogesterone Acetate / administration & dosage
  • Medroxyprogesterone Acetate / pharmacology
  • Progestins / administration & dosage
  • Progestins / pharmacology*
  • Simian Acquired Immunodeficiency Syndrome / immunology
  • Simian Acquired Immunodeficiency Syndrome / virology
  • Simian Immunodeficiency Virus / immunology
  • Simian Immunodeficiency Virus / pathogenicity*
  • T-Lymphocytes / immunology
  • Viral Load
  • Virus Replication


  • Contraceptive Agents, Female
  • Progestins
  • Interferon-gamma
  • Medroxyprogesterone Acetate