RECOGNITION OF PROTOZOAN PARASITE ANTIGENS BY MURINE LYMPHOCYTES-T .1. INDUCTION OF SPECIFIC LYMPHOCYTES-T-DEPENDENT PROLIFERATIVE RESPONSE TO LEISHMANIA-TROPICA

In order to assess the T cell response to Leishmania tropica in the mouse, a recently described method for the study of T lymphocyte activation by protein antigens has been used. Periaortic and inguinal lymph node cells obtained from mice previously injected at the base of the tail with L. tropica emulsified in complete Freund's adjuvant exhibited intense proliferation when cultured in the presence of parasites, as assessed by measuring of [3H]thymidine incorporation. The response was antigenspecific, was demonstrable from 4 to 75 days after in vivo priming and was T cell‐ dependent by the following criteria, (a) treatment of lymph node cells with rabbit anti‐mouse thymus lymphocyte antigen (MTLA) antiserum and complement greatly reduced the magnitude of the response, (b) purified T cells responded as efficiently as unfractionnated lymph node cells provided irradiated normal peritoneal exudate cells were also added to the culture. Finally, normal peritoneal exudate cells pulsed with L. tropica were able to induce a proliferative response of primed T cells in the absence of extracellular parasites. Therefore, this assay provides a reliable method to measure parasite‐induced T cell proliferation and a convenient system to study the nature of the interactions between antigen‐presenting cells and primed T cells in the induction of a specific T cell response to parasite antigens. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim