Cellular resistance to protozoal infection.

Several factors appear to determine cellular resistance to protozoal infection. As judged by the interaction at the cellular level between the oxygen-dependent and -independent antimicrobial mechanisms of the human mononuclear phagocyte and the intracellular protozoa, Toxoplasma gondii and Leishmania donovani, these determinants include the cell's state of maturation and activation, the magnitude of the phagocyte's oxidative burst capacity, the ability of the cell to respond specifically to parasite ingestion with the production of toxic oxygen intermediates, parasite susceptibility to H2O2, and the presence of and protozoan susceptibility to oxygen-independent mechanisms.