title: Expression of transporter associated with antigen processing-1 in the endocrine cells of human pancreatic islets: effect of cytokines and evidence of hyperexpression in IDDM.
abstract: A possible role of transporter associated with antigen processing (TAP)-1 in the pathogenesis of IDDM has been investigated by examining the level of TAP-1 expression in the islets of IDDM pancreas and by studying in vitro the effect of interferon (IFN)-gamma, IFN-alpha, and tumor necrosis factor-alpha in TAP-1 expression by cultured islet cells. A remarkable hyperexpression of TAP-1 has been found in the endocrine cells (beta and non-beta) of IDDM islets, which constitutes first evidence of hyperexpression of this molecule in the target organ of an autoimmune disease. TAP-1 hyperexpression correlated clearly with HLA class I hyperexpression but only very partially with HLA class II ectopic expression. IFN-gamma and IFN-alpha, both cytokines putatively implicated in IDDM pathogenesis, were capable of inducing TAP-1 protein (as assessed by immunofluorescence flow cytometry) and message (by Northern blot analysis and reverse transcription polymerase chain reaction). These findings suggest that under the influence of cytokines (most probably IFN-alpha) beta-cells may express in their surface a high density of HLA class I-peptide complexes that may facilitate their recognition and lysis by low-affinity CD8+ T-cells.
authors.affiliation: Immunology Unit, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Vives-Pi
authors.forename: M P
authors.initials: MP
authors.lastname: Armengol
authors.forename: L
authors.initials: L
authors.lastname: Alcalde
authors.forename: M
authors.initials: M
authors.lastname: Costa
authors.forename: N
authors.initials: N
authors.lastname: Somoza
authors.forename: F
authors.initials: F
authors.lastname: Vargas
authors.forename: D
authors.initials: D
authors.lastname: Jaraquemada
authors.forename: R
authors.initials: R
authors.lastname: Pujol-Borrell
mesh_terms: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters; D000293:Adolescent; D000328:Adult; D000368:Aged; D001483:Base Sequence; D002460:Cell Line; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology*; D017931:DNA Primers; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis*; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects* / Q000276:immunology; D006801:Humans; D016898:Interferon-alpha / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D007515:Islets of Langerhans / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D016133:Polymerase Chain Reaction; D011509:Proteoglycans / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters; D016207:Cytokines; D017931:DNA Primers; D016326:Extracellular Matrix Proteins; D016898:Interferon-alpha; D009419:Nerve Tissue Proteins; D011509:Proteoglycans; D011994:Recombinant Proteins; C073119:TAP1 protein, human; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma