CD8 + T cells from C57BL/6(B6) mice show cytotoxicity to B cell blasts prepared from syngeneic transgenic mice expressing HLADQ6 molecules in a mouse MHC class I H-2D b restricted manner. Although these results suggest that CD8 + T cells recognize peptides derived from DQ6 molecule bound to H-2D b on target cells, no direct evidence so far has been obtained. To clarify this, we synthesized 23 peptides corresponding to DQ6α or β chain and carrying the motifs of D b-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-2D b 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-2D b 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.
|Number of pages||8|
|Journal||Japanese Journal of Human Genetics|
|Publication status||Published - Dec 1 1997|
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