RECONSTITUTION OF MYCOBACTERIUM-LEPRAE IMMUNITY IN SEVERE COMBINED IMMUNODEFICIENT MICE USING A T-CELL LINE

To test whether Mycobacterium leprae-immune T cells can confer protect ion against infection with leprosy bacilli, severe combined immunodefi cient (SCID) mice were reconstituted with a BALB/c-derived, M. leprae- responsive, T-cell line. Flow cytometric analysis of spleen and periph eral blood cells confirmed reconstitution with T cells. In vitro lymph okine production and the proliferation of spleen cells from the recons tituted animals established that the donor cells had maintained their functional activity for the duration of the study (275 days). The tran sfer of immune T cells 24 hr before foot pad infection with leprosy ba cilli resulted in a profound reduction in M. leprae multiplication, as compared to the non-reconstituted SCID mice. The yield of acid-fast b acilli in the foot pads of SCID mice reconstituted with the M. leprae- immune T cells also was significantly lower than that found in naive B ALB/c mice, and at levels previously found only in BALB/c mice that ha d been immunized effectively. These experiments demonstrate that M. le prae-immune T cells home effectively and control M. leprae infection i n SCID mice.