Effects of splenectomy on antibody-independent immunity to Plasmodium chabaudi adami malaria.

Splenectomy of B-cell-deficient mice and immunologically intact mice before infection with Plasmodium chabaudi adami led to the development of significant parasitemias which eventually resolved in the latter mice. Whereas both eusplenic B-cell-deficient mice and immunologically intact mice resolved their acute P. chabaudi adami infection, only B-cell-deficient mice subsequently developed chronic low-grade malaria. Splenectomy of B-cell-deficient mice with chronic malaria led to recrudescing infections, suggesting that the expression of antibody-independent immunity to reinfection was spleen dependent. When dispersed spleen cells were injected into splenectomized mice before challenge with P. chabaudi adami, the kinetics of the resulting infection resembled that seen in splenectomized mice which had not been grafted with normal spleen cells. This finding indicates that immunity to P. chabaudi adami requires the presence of an architecturally intact spleen.