title: Soluble PD-1 rescues the proliferative response of simian immunodeficiency virus-specific CD4 and CD8 T cells during chronic infection.
abstract: Phenotypic and functional studies of the programmed death-1 (PD-1) molecule on CD4(+) and CD8(+) T cells were performed on peripheral blood mononuclear cells from uninfected and simian immunodeficiency virus (SIV)-infected rhesus macaques. These data demonstrated a rapid upregulation of PD-1 expression on tetramer-positive CD8(+) T cells from MamuA.01(+) SIV-infected macaques upon infection. Upregulation of PD-1 on total CD8(+) T cells was not detectable. In contrast, CD4(+) T-cell PD-1 expression was markedly higher in total CD4(+) T cells during chronic, but not acute, infection and there was a correlation between the level of PD-1 expression on naive and central memory CD4(+) T cells and the levels of viral loads. Such association was emphasized further by a marked decrease of PD-1 expression on tetramer-positive CD8 T cells as well as on CD4(+) T cells on longitudinal samples collected before and after the initiation of antiretroviral therapy and downregulation of viral replication in vivo. Cloning of PD-1 and its two ligands from several non-human primate species demonstrated > 95% conservation for PD-1 and PD-L2 and only about 91% homology for PD-L1. Functional studies using soluble recombinant PD-1 protein or PD-1-immunoglobulin G fusion proteins induced marked increases in the SIV-specific proliferative responses of both CD4(+) and CD8(+) T cells from rhesus macaques. The results of these studies serve as a foundation for future in vivo trials of the use of rMamu-PD-1 to potentially enhance and/or restore antiviral immune responses in vivo.
authors.affiliation: Department of Pathology & Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Nattawat
authors.initials: N
authors.lastname: Onlamoon
authors.forename: Kenneth
authors.initials: K
authors.lastname: Rogers
authors.forename: Ann E
authors.initials: AE
authors.lastname: Mayne
authors.forename: Kovit
authors.initials: K
authors.lastname: Pattanapanyasat
authors.forename: Kazuyasu
authors.initials: K
authors.lastname: Mori
authors.forename: Francois
authors.initials: F
authors.lastname: Villinger
authors.forename: Aftab A
authors.initials: AA
authors.lastname: Ansari
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D044966:Anti-Retroviral Agents / Q000627:therapeutic use; D051017:Apoptosis Regulatory Proteins / Q000097:blood / Q000235:genetics / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D002908:Chronic Disease; D008024:Ligands; D008253:Macaca mulatta; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D016097:Simian Acquired Immunodeficiency Syndrome / Q000188:drug therapy / Q000276:immunology* / Q000821:virology; D015302:Simian Immunodeficiency Virus / Q000302:isolation & purification; D012995:Solubility; D015854:Up-Regulation / Q000276:immunology; D019562:Viral Load
chemical_list: D044966:Anti-Retroviral Agents; D051017:Apoptosis Regulatory Proteins; D008024:Ligands; D012333:RNA, Messenger