Comparative studies on the roles of mediator molecules in expression of the suppressor activity ofMycobacterium aviumcomplex-induced immunosuppressive macrophages against T cell and B cell mitogenic responses

Abstract

Summary Mycobacterium avium complex-induced immunosuppressive macrophages (MAC-MΦ

Characteristics of Suppressor Macrophages Induced by Mycobacterial and Protozoal Infections in relation to Alternatively Activated M2 Macrophages

“…It has been found that MAC-induced suppressor macrophages also exhibit inhibitory activity against LPS-induced B-cell mitogenesis [ 99 ]. While NMMA and Carboxy-PTIO (nitric oxide scavenger) effectively blocked the macrophage suppressor activity against Con A-induced T-cell mitogenesis, the suppressor action against B-cell mitogenesis was only weakly affected by these nitric oxide-reducing agents.…”

“…In addition, B-cell mitogenesis was less susceptible to the inhibitory effects of the other suppressor macrophage-derived mediators, including free fatty acids, TGF- β and PGE 2 , than T-cell mitogenesis. Therefore, there are significant differences in the modes of suppressor action of MAC-induced suppressor macrophages against T-cell and B-cell mitogenesis [ 99 ]. Alternatively, it is also possible that MAC-induced suppressor macrophage populations are composed of two subpopulations with distinct functional properties: M1-type suppressor macrophages which mainly suppress T-cell functions in an RNI-dependent manner and M2-type suppressor macrophages which mainly act on B cells by producing suppressor mediators other than RNIs, presumably IL-10, TGF- β , and so on.…”