title: The immunosuppressive peptide of HIV-1 gp41 like human type I interferons up-regulates MHC class I expression on H9 and U937 cells.
abstract: Based on our findings that the immunosuppressive peptide (ISP, amino acids (aa) 583-599) of human immunodeficiency virus type 1 (HIV-1) gp41 shows sequence-similarity with human type I interferons (IFN-alpha and IFN-beta) and HIV-1 soluble gp41 (sgp41, aa 539-684) enhanced cell surface expression of major histocompatibility complex (MHC) class I molecule on human H9 (T cells), Raji (B cells) and U937 (monocytic cells) cells, we examined the effect of HIV-1 immunosuppressive peptide on the surface expression of MHC class I molecules on H9 and U937 cells. Flow cytometry analysis demonstrated that ISP-BSA (conjugate) could enhance MHC class I expression by about 40% on H9 cells and by about 45% on U937 cells, while monomer ISP (not conjugated) and EDCI-treated carrier protein (BSA-EDCI) did not increase the expression. By comparison, human type I interferons, IFN-alpha and IFN-beta, showed similar effects (enhanced the expression by about 40-60%) to ISP-BSA on the MHC class I expression on H9 and U937 cells. The results suggest that HIV-1 gp41 in a polymerized form by its immunosuppressive domain upregulates human MHC class I expression. The basis for this similar effect of HIV-1 gp41 and IFN-alpha and -beta, i.e. upregulation of MHC class I molecule expression, may be based on the sequence-similarity between these otherwise different molecules.
authors.affiliation: Department of Biological Science and Biotechnology, Tsinghua University, Beijing, China.
authors.forename: Y H
authors.initials: YH
authors.lastname: Chen
authors.forename: Y
authors.initials: Y
authors.lastname: Xiao
authors.forename: W
authors.initials: W
authors.lastname: Wu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhao
authors.forename: C
authors.initials: C
authors.lastname: Speth
authors.forename: M P
authors.initials: MP
authors.lastname: Dierich
mesh_terms: D000595:Amino Acid Sequence; D015700:HIV Envelope Protein gp41 / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007370:Interferon Type I / Q000276:immunology / Q000494:pharmacology; D016899:Interferon-beta / Q000276:immunology / Q000494:pharmacology; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology*; D011994:Recombinant Proteins; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
chemical_list: D015700:HIV Envelope Protein gp41; C100891:HIV envelope protein gp41 (583-599); D015395:Histocompatibility Antigens Class I; D007370:Interferon Type I; D010446:Peptide Fragments; D011994:Recombinant Proteins; D016899:Interferon-beta