title: Increased mortality and AIDS-like immunopathology in wild chimpanzees infected with SIVcpz.
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.
authors.affiliation: Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
authors.forename: Brandon F
authors.initials: BF
authors.lastname: Keele
authors.forename: James Holland
authors.initials: JH
authors.lastname: Jones
authors.forename: Karen A
authors.initials: KA
authors.lastname: Terio
authors.forename: Jacob D
authors.initials: JD
authors.lastname: Estes
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Rudicell
authors.forename: Michael L
authors.initials: ML
authors.lastname: Wilson
authors.forename: Yingying
authors.initials: Y
authors.lastname: Li
authors.forename: Gerald H
authors.initials: GH
authors.lastname: Learn
authors.forename: T Mark
authors.initials: TM
authors.lastname: Beasley
authors.forename: Joann
authors.initials: J
authors.lastname: Schumacher-Stankey
authors.forename: Emily
authors.initials: E
authors.lastname: Wroblewski
authors.forename: Anna
authors.initials: A
authors.lastname: Mosser
authors.forename: Jane
authors.initials: J
authors.lastname: Raphael
authors.forename: Shadrack
authors.initials: S
authors.lastname: Kamenya
authors.forename: Elizabeth V
authors.initials: EV
authors.lastname: Lonsdorf
authors.forename: Dominic A
authors.initials: DA
authors.lastname: Travis
authors.forename: Titus
authors.initials: T
authors.lastname: Mlengeya
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kinsel
authors.forename: James G
authors.initials: JG
authors.lastname: Else
authors.forename: Guido
authors.initials: G
authors.lastname: Silvestri
authors.forename: Jane
authors.initials: J
authors.lastname: Goodall
authors.forename: Paul M
authors.initials: PM
authors.lastname: Sharp
authors.forename: George M
authors.initials: GM
authors.lastname: Shaw
authors.forename: Anne E
authors.initials: AE
authors.lastname: Pusey
authors.forename: Beatrice H
authors.initials: BH
authors.lastname: Hahn
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000473:pathology; D000349:Africa; D000818:Animals; D000835:Animals, Wild; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D002679:Pan troglodytes / Q000821:virology*; D015995:Prevalence; D016097:Simian Acquired Immunodeficiency Syndrome / Q000453:epidemiology / Q000276:immunology / Q000401:mortality* / Q000473:pathology*; D015302:Simian Immunodeficiency Virus / Q000502:physiology*