title: Immunomodulation by peptide analogs of retroviral envelope protein.
abstract: The mechanism by which retroviral proteins exert their immunosuppressive influence has remained enigmatic. Early studies have demonstrated that retroviral infection suppresses cellular and humoral immune responses. A hydrophilic 26 amino acid region of the otherwise hydrophobic transmembrane envelope protein of murine and feline leukemia viruses, p15E, is conserved among the transmembrane envelope proteins of numerous animal retroviruses (e.g. murine, feline, bovine and simian) as well as in human T-cell leukemia virus, and to a lesser extent, in human immunodeficiency virus (HIV). We evaluated the immunomodulatory properties of various synthetic retroviral envelope peptides synthesized as overlapping fragments to this conserved sequence. We report that two small peptides inhibit human mixed lymphocyte reaction (MLR), interleukin-2 (IL-2) and tumor necrosis factor (TNF-alpha) production. These peptides did not affect human natural killer (NK) cell cytotoxicity in vitro, and nitric oxide (NO) production in mouse macrophage cells, RAW264.7. Our observations suggests immunomodulatory potential of two retroviral peptide analogs.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D003601:Cytotoxicity Tests, Immunologic; D006801:Humans; D007107:Immune System / Q000187:drug effects*; D007376:Interleukin-2 / Q000378:metabolism; D020014:K562 Cells / Q000276:immunology; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D007959:Lymphocyte Culture Test, Mixed; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D012191:Retroviridae Proteins / Q000737:chemistry*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000737:chemistry*
chemical_list: D007376:Interleukin-2; D008070:Lipopolysaccharides; D010455:Peptides; D010835:Phytohemagglutinins; D012191:Retroviridae Proteins; D014409:Tumor Necrosis Factor-alpha; D014759:Viral Envelope Proteins; D009569:Nitric Oxide