Macrophage functions in Biozzi mice.

The faster degradation of antigen by macrophages in Biozzi low (L) responder mice, compared to Biozzi high (H) responder mice, is thought to be responsible for their lower antibody response. We have measured four functions associated with macrophages to see whether macrophages from L mice were generally more active than those from H mice. Peritoneal macrophages obtained from normal mice were compared with those from groups of mice given Mycobacterium bovis BCG or Propionibacterium acnes. Cells from normal H mice gave a stronger oxidative burst when triggered with phorbol myristate acetate, and were more cytotoxic for tumour cells than cells from L mice. Cells from all mice injected with BCG or P. acnes gave a stronger oxidative burst, and were more cytotoxic for tumour cells; again, both responses were higher in H mice than in L mice. By contrast, when groups of mice that had received P. acnes were given endotoxin and bled, higher titres of tumour necrosis factor were found in the sera of L mice. Spleen cells from both lines of mice released similar levels of interleukin-1, both spontaneously and in response to lipopolysaccharide. Our results suggest that these various macrophage responses are expressed independently in H and L mice.