The effect of Leishmania tropica on stimulation of lymphocytes with phytohaemagglutinin.
Cell-mediated immune (CMI) responses are important in the immunity against leishmanial infections. However, infection persists in the presence of CMI for unknown reasons. Evidence is presented that L. tropica and its products are capable of inhibition of the stimulation of lymphocytes by PHA. This inhibition is dose dependent, and not dependent on competition for nutrients in the medium, nor on neutralization of PHA. The inhibition is observed on the lymphocytes of species susceptible to leishmanial infection, and not operative in resistant species. The mechanisms of the lymphocyte suppression are discussed.
D000818:Animals; D000941:Antigens; D002417:Cattle; D003470:Culture Media; D006168:Guinea Pigs; D007111:Immunity, Cellular; D007165:Immunosuppression Therapy; D066298:In Vitro Techniques; D037102:Lectins / Q000494:pharmacology*; D007891:Leishmania / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D013154:Spleen / Q000276:immunology; D013552:Swine
D000941:Antigens; D003470:Culture Media; D037102:Lectins