Kinetics of cell-mediated immunity developing during the course of Leishmania major infection in 'healer' and 'non-healer' mice: progressive impairment of response to and generation of interleukin-2.

Leishmania major (L. major)-infected mice of 'non-healer' (BALB/c) and 'healer' (C57BL/6) mouse-strain origin were studied with regard to the kinetics of cell-mediated immunity developing during the course of the disease. Cells obtained from lymph nodes draining L. major-infected footpads were comparatively analysed for their representation in the respective L3T4+, Lyt-2+ and sIg+ lymphocyte subsets; they were studied for their capacity to release interleukin-2 and to proliferate in response to L. major antigen and concanavalin A, including the determination of the frequencies of T cells proliferating antigen-specifically with or without an exogenous source of IL-2. The data obtained indicate L. major infection-induced long-lasting alterations in the cellular composition of the lymph node in both 'healer' and 'non-healer' mice. Moreover, they suggest that the inability of 'non-healer' mice to recover from L. major infection is associated with a progressive impairment of their lymph node T cells to release interleukin-2 in the culture supernatant and to respond to this lymphokine in vitro.