title: Effects of SIVmac infection on peripheral blood CD4+CD8+ T lymphocytes in cynomolgus macaques.
abstract: We have previously reported that CD4+CD8+ double-positive (DP) T cells with a resting memory phenotype exist in a substantial proportion of peripheral blood lymphocytes of adult cynomolgus macaques. In this study, we examined the effects of simian immunodeficiency virus of macaque (SIVmac) infection on DP T cells. In vitro, SIVmac239 nef-open (239) and its nef-deletion mutant replicated well in both CD4+CD8- and DP T cells. However, when the macaques were infected with 239, DP, but not CD4+CD8-, T cells were transiently increased in parallel with cell activation and viral replication, followed by depletion within 1 month postinfection. Interestingly, the nef gene was required for depletion but not for the increase and activation of DP T cells. These data suggest that the pathogenic SIV infection may downmodulate production and/or blood circulation of DP T cells by a Nef function-related mechanism(s) different from that for the depletion of CD4+CD8- T cells.
authors.affiliation: Tsukuba Primate Center, National Institute of Infectious Diseases, Ibaraki, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Akari
authors.forename: K H
authors.initials: KH
authors.lastname: Nam
authors.forename: K
authors.initials: K
authors.lastname: Mori
authors.forename: I
authors.initials: I
authors.lastname: Otani
authors.forename: H
authors.initials: H
authors.lastname: Shibata
authors.forename: A
authors.initials: A
authors.lastname: Adachi
authors.forename: K
authors.initials: K
authors.lastname: Terao
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshikawa
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D017353:Gene Deletion; D015754:Genes, nef; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D008252:Macaca fascicularis; D012367:RNA, Viral / Q000097:blood; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000821:virology; D015302:Simian Immunodeficiency Virus / Q000235:genetics / Q000472:pathogenicity; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013997:Time Factors; D014766:Viremia / Q000821:virology; D014774:Virulence / Q000235:genetics
chemical_list: D012367:RNA, Viral