T cell proliferation in Mycobacterium lepraemurium infection. I. Lack of correlation between antigen-specific proliferation of Lyt 1 + 23- cells and resistance in lethal infections.

Antigen specific T lymphocyte proliferation and Lyt phenotypes of the T lymphocytes were studied in BALB/c and C57BL/6 mice infected with 10(9) M. lepraemurium organisms intravenously. A highly disseminated form of the disease developed to which all mice succumbed by 17 weeks. Maximal antigen-specific T lymphocyte proliferation was detected at 4 weeks after the infection and persisted thereafter even when the mice started to die of the infection. Accessory cells of phagocytic and adherent type did not appear to be a requirement for this proliferation. The T lymphocytes generated during the course of the infection were mostly of the Lyt 1 phenotype. However, there appeared to be no correlation between sensitized Lyt 1 cells capable of antigen-induced T lymphocyte proliferation and protective immunity.