Humoral immune activity in CBA/Ca mice during late pregnancy and the post-partum period

Abstract

Syngeneically mated CBA/Ca mice were used to measure “spontaneous” immunoglobulin (Ig) secretion in the Peyer's patches (PP), spleen and the para-aortic lymph nodes (PALN), employing a protein A plaque assay, during the latter part of pregnancy and in the post-partum period. The lactating and non-lactating females were compared with respect to humoral immune activity (plaque-forming cells) and serum Ig levels (ELISA technique). The pregnancy-induced weight changes in some lymphoid organs and the elevation in the number of plaque-forming cells in spleen (IgG and IgM PFC), PALN (IgG and IgM PFC) and the PP (IgA PFC) lasted longer in the lactating than in the non-lactating mice (owing to hormonal differences). A very strong decrease in serum IgG was observed during pregnancy and after parturition IgG levels remained depressed longer in lactating than in non-lactating mice. Interest has been focused on IgA in the study and this has been discussed as well as the possible reasons for the increased turnover of maternal serum Ig (especially IgG).