IFN-gamma Inhibits Development of Plasmodium berghei Exoerythrocytic Stages inHepatocytes by an L-Arginine-Dependent Effector Mechanism

摘要

Malaria is transmitted to animals and humans by the bite of mosquitoes thatinject sporozoites. The sporozoites rapidly pass through the circulatory system to the liver where each uninucleate sporozoite can develop during several days to a liver stage schizont with up to 3 x 104 uninucleate merozoites depending on the species of Plasmodium. Immunization of mice and humans with attenuated malaria sporozoites confers stage-specific protective immunity to viable sporozoite challenge; protective immune responses are directed against circulating sporozoites or developing parasites within hepatocytes. Most evidence indicates that antibodies mediate the activity against circulating sporozoites, and that cytotoxic T lymphocytes and lymphokines, especially IFN-gamma, are involved in the destruction of developing liver stage parasites.