title: Identification of an HLA-DQ6-derived peptide recognized by mouse MHC class I H-2Db-restricted CD8+ T cells in HLA-DQ6 transgenic mice.
abstract: CD8+ T cells from C57BL/6(B6) mice show cytotoxicity to B cell blasts prepared from syngeneic transgenic mice expressing HLA-DQ6 molecules in a mouse MHC class I H-2Db restricted manner. Although these results suggest that CD8+ T cells recognize peptides derived from DQ6 molecule bound to H-2Db on target cells, no direct evidence so far has been obtained. To clarify this, we synthesized 23 peptides corresponding to DQ6 alpha or beta chain and carrying the motifs of Db-binding peptides, and examined their capacity to induce cytotoxicity in the CD8+ T cell line. We show here that DQA1-2, one of these peptides, induced cytotoxicity of the CD8+ T cells when this peptide was pulsed to H-2Db expressing target cells, as efficiently as HLA-DQ6 expressing target cells did. Thus, our results suggest that DQA1-2 can be naturally processed from DQ6 molecules and recognized by the CD8+ T cells in the context of H-2Db molecules. These results suggest that allogeneic HLA class II molecules are involved in the rejection not only as the ligand for T cell receptor of alloreactive CD4+ T cells but also as self-peptides bound to HLA class I molecules recognized by CD8+ T cells.
authors.affiliation: Department of Genetics, Kyushu University, Fukuoka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takeshita
authors.forename: Y
authors.initials: Y
authors.lastname: Fukui
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.forename: K
authors.initials: K
authors.lastname: Yamane
authors.forename: T
authors.initials: T
authors.lastname: Inamitsu
authors.forename: N
authors.initials: N
authors.lastname: Kamikawaji
authors.forename: T
authors.initials: T
authors.lastname: Sasazuki
mesh_terms: D000818:Animals; D000937:Antigen-Antibody Reactions; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D006183:H-2 Antigens / Q000276:immunology*; D006683:HLA-DQ Antigens / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008822:Mice, Transgenic; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000276:immunology; D011485:Protein Binding
chemical_list: D006183:H-2 Antigens; D006683:HLA-DQ Antigens; D015395:Histocompatibility Antigens Class I; D009842:Oligopeptides