Induction of cell-mediated immunity to Mycobacterium lepraemurium in susceptible mice.

A mouse strain (CB6) that is highly susceptible to Mycobacterium lepraemurium was infected with 10(8) bacilli into the hind footpad. These mice developed cell-mediated immunity to M. lepraemurium, as expressed by the development of a granulomatous lesion at the site of inoculation in normal but not in T-lymphocyte-depleted mice, a proliferative response in the paracortical zone of the draining lymph node, delayed-type hypersensitivity to a sonic extract of M. lepraemurium, and immunopotentiation of the delayed hypersensitivity response to sheep erythrocytes. Resistance to a second challenge infection with M. lepraemurium was not demonstrated.