Microbicidal activity and morphological characteristics of lung macrophages in Mycobacterium bovis BCG cell wall-induced lung granuloma in mice.

Morphological and functional changes in lung macrophages from mice injected intravenously with Mycobacterium bovis BCG cell walls (CWs) were studied. In BCG CW high-responder mice (C57BL/6 [B6] strain), an increase in the size and the acid phosphatase activity of lung macrophages was observed. These lung macrophages showed greater microbicidal activity to M. bovis Ravenel and Listeria monocytogenes EGD, enhanced superoxide anion production index, and greater macrophage migration inhibition activity, as compared with lung macrophages from BCG CW low-responder mice (C3H/He strain), which were small in size and showed weak acid phosphatase activity, low antimicrobial activity, and low superoxide anion production index upon intravenous injection of the mice with BCG CW. These results indicated that lung macrophages from B6 mice injected with BCG CWs were morphologically and functionally activated, but not those from C3H mice.