Host defense in Cryptococcosis. III. In vivo alteration of immunity.

The present studies utilize an inbred mouse model to evaluate the adoptive transfer of spleen cells to augment immunity against Cryptococcus neoformans. Protection against cryptococcosis was transferred using spleen cells obtained from mice surviving cryptococcosis. These spleen cell donors had no detectable anticryptococcal antibody. Also, treatment with antimouse-thymocyte globulin ablated dermal hypersensitivity reactions of immunized mice, and shortened survival in both immunized and unimmunized mice. These in vivo studies further support a major role for cell-mediated immunity in host defense against experimental cryptococcosis.