Abstract

The IgG-subclass usage by several strains of mice in the response to immunization with mouse thyroglobulin (mTg) was examined in the experimental autoimmune thyroiditis model. While the subclass usage by most mouse strains was similar, the Igh(b) allotype-bearing mice consistently produced lower IgG2a levels to mTg. Using CBA-Igh(b) congenic and recombinant inbred strains of mice, the lower level of IgG2a in the Igh(b) mouse was mapped to the Igh locus. The regulation of IgG2a appeared to be cis controlled, as the CBA x C57BL/6F(1) mouse also produced reduced IgG2a of the Igh(b) (B6) allotype but not of the Igh(j) (CBA) allotype.