[M1 AND M2 MACROPHAGE POPULATIONS: THOSE INDUCED AND ACTIVATED BY MYCOBACTERIAL INFECTIONS]

Abstract

In the advanced stages of mycobacterial infections, host immune systems tend to change from a Th1-type to Th2-type immune response, resulting in the abrogation of Th1 cell- and macrophage-mediated antimicrobial host protective immunity. Notably, this type of immune conversion is occasionally associated with the generation of. certain types of suppressor macrophage populations. During the course of infections due to pathogenic mycobacteria, the generation of macrophages which possess strong suppressor activity against host T- and B-cell functions is frequently encountered. This review describes the immunological properties of M1- and M2-type macrophages generated in hosts with certain microbial infections including mycobacteriosis and those generated in tumor-bearing animals. Particularly, this paper highlights the immunological and molecular biological characteristics of M1 and M2 macrophage populations, which are induced by mycobacterial infections