Review: cytokines and malaria.

Malaria, which is caused by hemoprotozoan parasites of the genus Plasmodium, has once again reached epidemic proportions. The resurgence of malaria has occurred because the parasite has developed resistance to the anti-malarial drugs and the mosquito vector has developed resistance to the insecticides. Added to these impediments is the problem that, in spite of intense efforts by researchers world-wide, there is yet no effective anti-malarial vaccine. Our lack of knowledge concerning the exact mechanism of the host immune response to infection with Plasmodium parasites has contributed significantly to the lack of an effective and safe vaccine. The role of an antibody-independent, cell-mediated mechanism which can result in the generation of soluble mediators or cytokines by T lymphocytes and macrophages in host defense against blood stage malaria is being actively investigated in humans and in mice with malaria. With the availability of recombinant lymphokines and monokines and neutralizing antibodies against these reagents it is now possible to determine the role of cytokines in the development of protective anti-malarial immunity. In this review, we discuss recent evidence from human studies and experimental murine models concerning the possible roles of cytokines in malaria.