Increased mortality and AIDS-like immunopathology in wild chimpanzees infected with SIVcpz.

Academic Article

Abstract

  • African primates are naturally infected with over 40 different simian immunodeficiency viruses (SIVs), two of which have crossed the species barrier and generated human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2). Unlike the human viruses, however, SIVs do not generally cause acquired immunodeficiency syndrome (AIDS) in their natural hosts. Here we show that SIVcpz, the immediate precursor of HIV-1, is pathogenic in free-ranging chimpanzees. By following 94 members of two habituated chimpanzee communities in Gombe National Park, Tanzania, for over 9 years, we found a 10- to 16-fold higher age-corrected death hazard for SIVcpz-infected (n = 17) compared to uninfected (n = 77) chimpanzees. We also found that SIVcpz-infected females were less likely to give birth and had a higher infant mortality rate than uninfected females. Immunohistochemistry and in situ hybridization of post-mortem spleen and lymph node samples from three infected and two uninfected chimpanzees revealed significant CD4(+) T-cell depletion in all infected individuals, with evidence of high viral replication and extensive follicular dendritic cell virus trapping in one of them. One female, who died within 3 years of acquiring SIVcpz, had histopathological findings consistent with end-stage AIDS. These results indicate that SIVcpz, like HIV-1, is associated with progressive CD4(+) T-cell loss, lymphatic tissue destruction and premature death. These findings challenge the prevailing view that all natural SIV infections are non-pathogenic and suggest that SIVcpz has a substantial negative impact on the health, reproduction and lifespan of chimpanzees in the wild.
  • Published In

  • Nature  Journal
  • Keywords

  • Acquired Immunodeficiency Syndrome, Africa, Animals, Animals, Wild, CD4-Positive T-Lymphocytes, Female, Humans, Male, Molecular Sequence Data, Pan troglodytes, Prevalence, Simian Acquired Immunodeficiency Syndrome, Simian Immunodeficiency Virus
  • Digital Object Identifier (doi)

    Author List

  • Keele BF; Jones JH; Terio KA; Estes JD; Rudicell RS; Wilson ML; Li Y; Learn GH; Beasley TM; Schumacher-Stankey J
  • Start Page

  • 515
  • End Page

  • 519
  • Volume

  • 460
  • Issue

  • 7254