Properties of immunosuppressive macrophages generated by Mycobacterium intracellulare infection in M. intracellulare-susceptible and resistant mice.

Splenic macrophages (M(phi)s) generated in Mycobacterium intracellulare (Min)-infected mice exhibit suppressor activity against T cell mitogenesis. We examined profiles of the Min-induced generation of immunosuppressive M(phi)s (Min-M(phi)s) in Min-susceptible BALB/c (bcg(s)) and resistant CBA/JN (bcg(r)) mice. Min infection in BALB/c mice caused a more rapid generation of the immunosuppressive M(phi)s, which expressed M(phi) markers such as CD11b and F4/80, exhibited an increased ability to generate reactive oxygen intermediates, and inhibited IL-2 receptor expression by mitogenic T cells, than did Min infection in CBA/JN mice. Thus, the bcg gene may be related to the generation of Min-M(phi)s in host mice.