Existence of mixed isotype A beta E alpha class II molecules in Ed alpha gene-introduced C57BL/6 transgenic mice.

In this study the existence of mixed isotype Ab beta Ed alpha molecules in Ed alpha gene-introduced C57BL/6 (B6Ed alpha) transgenic mice is demonstrated. Biosynthetically labelled B6Ed alpha transgenic spleen cells were immunoprecipitated with anti-Ab beta or anti-Ed alpha monoclonal antibody (mAb) and analysed by two-dimensional gel electrophoresis (NEPHGE/SDS-PAGE). Anti-Ab beta mAb precipitated Ed alpha molecules in addition to Ab beta and Ab alpha molecules. Anti-Ed alpha mAb precipitated Ab beta molecules in addition ot Eb beta and Ed alpha molecules. No Ed alpha molecule was precipitated by anti-Ab beta mAb from B10.A(3R) spleen cells, which have a very similar organization of class II molecules to B6Ed alpha transgenic mice. Since this B6Ed alpha transgenic mouse was shown to have 20-40 copies per cell of the Ed alpha transgene (Kashiwamura et al., 1988), it is speculated that large amounts of Ed alpha transgene are made but, according to the data presented here, only a small amount actually associates with Ab beta as opposed to Eb beta.