Modulation of primary antibody responses to sheep erythrocytes in Plasmodium chabaudi-infected resistant and susceptible mouse strains.

The in vivo primary antibody response to sheep erythrocytes (SRBC) was determined in genetically resistant C57BL/6 and susceptible A/J mice during the course of infection with Plasmodium chabaudi. Spleen cells from both strains of mice, immunized with SRBC and infected on the same day, showed significant increases in the number of direct plaque-forming cells. The response of malaria-infected C57BL/6 mice was significantly enhanced in comparison with the responses of both normal C57BL/6 and malaria-infected A/J mice. When mice were immunized at later times in the infection, the level of the response declined in both strains until it was less than 50% of the response of normal mice. Thus, suppression of the primary antibody response to SRBC does not correlate with the outcome of P. chaubaudi infection in genetically resistant and susceptible hosts.