Biochemical and functional analysis of mixed isotype A beta E alpha class II molecules in Ed alpha transgenic mice.

We demonstrated the existence of mixed isotype A beta E alpha class II molecules in Ed alpha gene-introduced C57BL/6 (B6Ed alpha) transgenic mice. Immunoprecipitation and two dimensional (NEPHGE/SDS-PAGE) gel electrophoresis analysis of labeled B6Ed alpha spleen cell lysates using monoclonal anti-Ab beta antibody showed Ed alpha spots in addition to Ab beta and Ab alpha spots. We obtained alloreactive T cell clones from B6 anti-B6Ed alpha long-term cultures that recognized the Ab beta Ed alpha molecule. We also obtained antigen reactive T cell clones that recognized antigen in the context of Ad beta Ed alpha mixed isotype class II molecules. The importance of the mixed isotype class II molecules in relation to the expansion of the T cell specificity repertoire as well as autoimmune induction is discussed.