title: A highly conserved sequence associated with the HIV gp41 loop region is an immunomodulator of antigen-specific T cells in mice.
abstract: Modulation of T-cell responses by HIV occurs via distinct mechanisms, 1 of which involves inactivation of T cells already at the stage of virus-cell fusion. Hydrophobic portions of the gp41 protein of the viral envelope that contributes to membrane fusion may modulate T-cell responsiveness. Here we found a highly conserved sequence (termed "ISLAD") that is associated with the membranotropic gp41 loop region. We showed that ISLAD has the ability to bind the T-cell membrane and to interact with the T-cell receptor (TCR) complex. Furthermore, ISLAD inhibited T-cell proliferation and interferon-γ secretion that resulted from TCR engagement through antigen-presenting cells. Moreover, administering ISLAD (10 µg per mouse) to an experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis reduced the severity of the disease. This was related to the inhibition of pathogenic T-cell proliferation and to reduced pro-inflammatory cytokine secretion in the lymph nodes of ISLAD-treated EAE mice. The data suggest that T-cell inactivation by HIV during membrane fusion may lie in part in this conserved sequence associated with the gp41 loop region.
authors: Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel.
authors: Avraham
authors: A
authors: Ashkenazi
authors: Omri
authors: O
authors: Faingold
authors: Nathali
authors: N
authors: Kaushansky
authors: Avraham
authors: A
authors: Ben-Nun
authors: Yechiel
authors: Y
authors: Shai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D017124:Conserved Sequence / Q000235:genetics / Q000502:physiology*; D015700:HIV Envelope Protein gp41 / Q000737:chemistry / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D015658:HIV Infections / Q000276:immunology; D015497:HIV-1 / Q000235:genetics / Q000276:immunology; D006801:Humans; D007155:Immunologic Factors / Q000235:genetics* / Q000276:immunology; D019169:Jurkat Cells; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary / Q000235:genetics; D015302:Simian Immunodeficiency Virus / Q000235:genetics / Q000276:immunology; D037182:T-Cell Antigen Receptor Specificity / Q000235:genetics* / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
chemical_list: D015700:HIV Envelope Protein gp41; D007155:Immunologic Factors