Cellular subsets involved in cell-mediated immunity to murine Plasmodium yoelii 17X malaria.
Cell mediated immunity to nonlethal Plasmodium yoelli 17X (PY17X-NL) was examined in the CBA/CaJ mouse by adoptive transfer of sensitized T lymphocyte subsets. In intact mice, PY17X-NL causes a self-limiting infection with parasitemia levels ranging from 10 to 25% of total red blood cells. Upon recovery, mice are refractory to subsequent challenge with the homologous parasite. In T cell-depleted mice, PY17X-NL infections are extremely virulent and result in death of the host after parasitemia levels reach 50% or higher. The transfer of either Lyt-1 T cells or Lyt-2 T cells from immune animals into normal, naive animals produced accelerated recovery to subsequent infection. However, this adoptive transfer of immunity by either subset was dependent upon the presence of an I-J+, Lyt-null cell in the immune population. T cell deprivation precluded the ability of animals to control blood-stage infections. When T cell-depleted mice were reconstituted with naive, Ig-negative (T cell-enriched) spleen cells, parasitemia levels were controlled and the parasites were eliminated. When T cell-deprived animals were reconstituted with naive Lyt-1+2-, Ig-negative spleen cells, they experienced twofold higher parasitemias of longer duration than mice receiving unfractionated cells. Two of six of these Lyt-1 mice died of fulminant infections, suggesting that the presence of naive Lyt-2 cells enhances the degree of protection. Immune Lyt-2 T cells were highly protective in T cell-depleted animals. Protection by sensitized Lyt-1 T cells correlated with the induction of a monocytosis. On the other hand, protection by Lyt-2T cells occurred in the absence of monocytosis. The possibility that the immunity induced by each T cell subset is mediated by a different effector mechanism is discussed.
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte; D000953:Antigens, Protozoan / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis; D006183:H-2 Antigens / Q000276:immunology; D007111:Immunity, Cellular; D007116:Immunization, Passive; D007958:Leukocyte Count; D008214:Lymphocytes / Q000145:classification / Q000276:immunology*; D008215:Lymphocytes, Null / Q000145:classification / Q000276:immunology; D008288:Malaria / Q000276:immunology* / Q000469:parasitology; D051379:Mice; D008815:Mice, Inbred Strains; D009000:Monocytes / Q000276:immunology; D010961:Plasmodium / Q000276:immunology*; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology
D000945:Antigens, Differentiation, T-Lymphocyte; D000953:Antigens, Protozoan; D000954:Antigens, Surface; D006183:H-2 Antigens