Evidence for serum factors modulating antibody production in normal and macular mice

The macular mutant mouse is a model of Menkes' kinky hair disease, which is characterized by a deficiency of ceruloplasmin in the serum. In hemizygotic mice (ml/y), the antibody production against sheep red blood cells (SRBC) was decreased. Treatment with normal (+/y) mouse serum increased in a dose-dependent manner the antibody response of ml/y mouse spleen cells in vitro. However, +/y mouse serum had no effect on +/y mouse spleen cells, even at high doses up to 5%. In contrast, ml/y mouse serum decreased antibody production in +/y mouse spleen cells in a dose-dependent manner. Antibody production in +/y mouse spleen cells decreased with time, after pretreatment with ml/y mouse serum. However, serum from ml/y mice injected with ceruloplasmin did not decrease antibody production in +/y mouse spleen cells but rather increased it in ml/y mouse spleen cells. Ceruloplasmin had no effect on the production of antibodies against SRBC in ml/y and +/y mouse spleen cells in vitro. These findings suggest that one or more enhancers of antibody production exist in normal mouse serum and that one or more suppressors of normal antibody production exist in ml/y mouse serum. It is proposed that the activities of these factors in serum may be regulated by ceruloplasmin.