Malaria-induced increase of splenic γδ T cells in humans, monkeys, and mice

The number and distribution of γδ T cells in spleens from patients who died of cerebral malaria and from rhesus monkeys severely infected with Plasmodium coatneyi were examined by immunocytochemistry. γδ T cells were significantly increased in these spleens. In a rodent malaria model using Plasmodium chabaudi adami, an avirulent strain of murine malaria parasites, the degree of parasitemia appears to be modulated by the number of γδ T cells in the spleen. As parasitemia increases, these T cells increase in number. At some critical point, γδ T cells in collaboration with macrophages and αβ T cells apparently start to clear parasitized erythrocytes from the blood, leading to an abatement of the parasitemia, which is followed by a reduction in the number of γδ T cells. This γδ T cell phenomenon may be responsible for the self-limiting infection in mice.