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

Nature. 2009 Jul 23;460(7254):515-9. doi: 10.1038/nature08200.

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acquired Immunodeficiency Syndrome / pathology
  • Africa
  • Animals
  • Animals, Wild
  • CD4-Positive T-Lymphocytes / immunology
  • Female
  • Humans
  • Male
  • Molecular Sequence Data
  • Pan troglodytes / virology*
  • Prevalence
  • Simian Acquired Immunodeficiency Syndrome / epidemiology
  • Simian Acquired Immunodeficiency Syndrome / immunology
  • Simian Acquired Immunodeficiency Syndrome / mortality*
  • Simian Acquired Immunodeficiency Syndrome / pathology*
  • Simian Immunodeficiency Virus / physiology*

Associated data

  • GENBANK/FJ895381
  • GENBANK/FJ895382
  • GENBANK/FJ895383
  • GENBANK/FJ895384
  • GENBANK/FJ895385
  • GENBANK/FJ895386
  • GENBANK/FJ895387
  • GENBANK/FJ895388
  • GENBANK/FJ895389
  • GENBANK/FJ895390
  • GENBANK/FJ895391
  • GENBANK/FJ895392
  • GENBANK/FJ895393
  • GENBANK/FJ895394
  • GENBANK/FJ895395
  • GENBANK/FJ895396
  • GENBANK/FJ895397
  • GENBANK/FJ895398
  • GENBANK/FJ895399
  • GENBANK/FJ895400
  • GENBANK/FJ895401
  • GENBANK/FJ895402
  • GENBANK/FJ895403
  • GENBANK/FJ895404
  • GENBANK/FJ895405