In vitro and in vivo evidence for high frequency of I-Ab-reactive CD4+ T cells in HLA-DQ or HLA-DRA transgenic mice lacking endogenous MHC class I and/or class II expression.

摘要: Although T cells are educated to recognize foreign antigenic peptides in the context of self MHC molecules during their development thymus, peripheral also allo- and xeno-MHC molecules. The lower frequency xeno-MHC-reactive than that allo-MHC-reactive is often explained by difference degree homology between xeno- or allo-MHC molecules, as well species barrier involved immune recognition. To distinguish these two possibilities, we estimated I-Ab-reactive CD4+ selected HLA-DQ DR alpha E beta b using HLA-DQ6 HLA-DRA transgenic C57BL/6 (B6) mice lacking endogenous class I and/or II (DQ6A0/0 30A0/0 20/0). lymph node from DQ6A0/0 20/0 showed strong proliferative response I-Ab In addition, rejected skin graft expressing irrespective expression, indicating recognizing directly this rejection. CD4(+)CD8- thymocytes was comparable with observed II-disparate strains. Our findings thus indicate mature on such b, when expressed mice, II, despite less structural homology.