Human T lymphocyte clones specific for malaria (Plasmodium falciparum) antigens.

Peripheral blood mononuclear cells (PBM) from a patient who had lived in a malarial-endemic area were cultured in the presence of malarial antigens (a lysate of Plasmodium-infected erythrocytes). Responding cells were grown in IL-2-containing medium and then cloned, and subsequently subcloned, in the presence of phytohemagglutinin and allogeneic irradiated PBM. Ten clones were specific for malarial antigens. They proliferated in response to P. falciparum extract, but not to a lysate of uninfected erythrocytes. The response was HLA-restricted. All the clones tested responded to lysates of cells infected with parasites of either African or Asian origin. Six clones had the T4+/T8- phenotype and four the T4-/T8+ phenotype. Two of the T4+ clones recognised a parasite antigen of apparent mol. wt. approximately 50 000. All of the clones tested produced gamma-interferon following antigen stimulation.