Immunosuppression in mice after inhalation of cadmium aerosol

Aerosol cadmium (CdCl2) exposure of female C57Bl/6 mice was performed to assess the in vivo effects of cadmium on the cellular and humoral immune responses of splenic lymphocytes. Primary cellular and humoral responses of lymphocytes were examined at 5-18 days after a single, 60 min exposure to 0.88 mg Cd/m3 (MMAD = 0.7 +/- 0.3 micron, sigma g = 3.43). Significant decrease of in vitro lymphoproliferative response to allogeneic antigens, LPS and PHA antigens, and inhibition of the primary IgM response to sheep erythrocytes were correlated with a marked decrease in spleen cell viability at 5-8 days after aerosol cadmium exposure. This type of cadmium-induced immunosuppression, which correlated with the direct cytotoxicity of effector cells, appeared to be different from the chronic, oral cadmium-induced suppression of the primary IgM response, in which acute cytotoxicity of the spleen cell population was not observed.