The effect of cadmium on antibody responses to antigens with different cellular requirements.

Six week old BDF1 or CD-1 female mice were exposed to cadmium chloride in the drinking water at concentrations ranging from 0 to 50 ppm cadmium for 3 weeks. The in vivo antibody response against dinitrophenyl-aminoethylcarbamylmethyl-Ficoll (DNP-Ficoll), a T-lymphocyte independent, macrophage dependent response, was enhanced by cadmium. Similarly, the in vivo antibody response against Escherichia coli 0127 (LPS), a T-lymphocyte and macrophage independent response, was also enhanced by cadmium. In contrast, the in vitro antibody response against sheep red blood cells (SRBC), a T-lymphocyte and macrophage dependent response, was suppressed in spleen cell cultures that contained cadmium-exposed non-adherent cells (lymphocytes). Cultures containing cadmium-exposed adherent cells (macrophages) were not suppressed by cadmium. These results suggest that the immunosuppressive effects of cadmium as it relates to humoral immunity involve T-lymphocyte function rather than macrophage or B-lymphocyte activity. The enhanced T-lymphocyte independent antibody responses which accompany suppressed T-lymphocyte-dependent responses following cadmium exposure are an indication of compensatory mechanisms that are associated with the immune system.