title: Characterization of a new simian immunodeficiency virus strain in a naturally infected Pan troglodytes troglodytes chimpanzee with AIDS related symptoms.
abstract: BACKGROUND
  Data on the evolution of natural SIV infection in chimpanzees (SIVcpz) and on the impact of SIV on local ape populations are only available for Eastern African chimpanzee subspecies (Pan troglodytes schweinfurthii), and no data exist for Central chimpanzees (Pan troglodytes troglodytes), the natural reservoir of the ancestors of HIV-1 in humans. Here, we report a case of naturally-acquired SIVcpz infection in a P.t.troglodytes chimpanzee with clinical and biological data and analysis of viral evolution over the course of infection.
  
  
  RESULTS
  A male chimpanzee (Cam155), 1.5 years, was seized in southern Cameroon in November 2003 and screened SIV positive during quarantine. Clinical follow-up and biological analyses have been performed for 7 years and showed a significant decline of CD4 counts (1,380 cells/mm³ in 2004 vs 287 in 2009), a severe thrombocytopenia (130,000 cells/mm³ in 2004 vs 5,000 cells/mm³ in 2009), a weight loss of 21.8% from August 2009 to January 2010 (16 to 12.5 kg) and frequent periods of infections with diverse pathogens.DNA from PBMC, leftover from clinical follow-up samples collected in 2004 and 2009, was used to amplify overlapping fragments and sequence two full-length SIVcpzPtt-Cam155 genomes. SIVcpzPtt-Cam155 was phylogenetically related to other SIVcpzPtt from Cameroon (SIVcpzPtt-Cam13) and Gabon (SIVcpzPtt-Gab1). Ten molecular clones 5 years apart, spanning the V1V4 gp120 env region (1,100 bp), were obtained. Analyses of the env region showed positive selection (dN-dS >0), intra-host length variation and extensive amino acid diversity between clones, greater in 2009. Over 5 years, N-glycosylation site frequency significantly increased (p < 0.0001).
  
  
  CONCLUSIONS
  Here, we describe for the first time the clinical history and viral evolution of a naturally SIV infected P.t.troglodytes chimpanzee. The findings show an increasing viral diversity over time and suggest clinical progression to an AIDS-like disease, showing that SIVcpz can be pathogenic in its host, as previously described in P.t.schweinfurthii. Although studying the impact of SIV infection in wild apes is difficult, efforts should be made to better characterize the pathogenicity of the ancestors of HIV-1 in their natural host and to find out whether SIV infection also plays a role in ape population decline.
authors.affiliation: UMR145, Institut de Recherche pour le Développement (IRD) and Université Montpellier 1, Montpellier, France.
authors.forename: Lucie
authors.initials: L
authors.lastname: Etienne
authors.forename: Eric
authors.initials: E
authors.lastname: Nerrienet
authors.forename: Matthew
authors.initials: M
authors.lastname: LeBreton
authors.forename: Godwin Tafon
authors.initials: GT
authors.lastname: Bibila
authors.forename: Yacouba
authors.initials: Y
authors.lastname: Foupouapouognigni
authors.forename: Dominique
authors.initials: D
authors.lastname: Rousset
authors.forename: Ahmadou
authors.initials: A
authors.lastname: Nana
authors.forename: Cyrille F
authors.initials: CF
authors.lastname: Djoko
authors.forename: Ubald
authors.initials: U
authors.lastname: Tamoufe
authors.forename: Avelin F
authors.initials: AF
authors.lastname: Aghokeng
authors.forename: Eitel
authors.initials: E
authors.lastname: Mpoudi-Ngole
authors.forename: Eric
authors.initials: E
authors.lastname: Delaporte
authors.forename: Martine
authors.initials: M
authors.lastname: Peeters
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Wolfe
authors.forename: Ahidjo
authors.initials: A
authors.lastname: Ayouba
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis; D000818:Animals; D018791:CD4 Lymphocyte Count; D002163:Cameroon; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D019143:Evolution, Molecular; D016679:Genome, Viral; D008297:Male; D008969:Molecular Sequence Data; D002679:Pan troglodytes / Q000821:virology*; D011533:Proviruses / Q000235:genetics; D017422:Sequence Analysis, DNA; D016097:Simian Acquired Immunodeficiency Syndrome / Q000473:pathology / Q000821:virology*; D015302:Simian Immunodeficiency Virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D013921:Thrombocytopenia / Q000175:diagnosis; D015431:Weight Loss
chemical_list: D004279:DNA, Viral