Studies on phagocyte response to bacteria: conditions for efficient interaction and mechanism of oxygen radical production.

In efforts to elucidate the role of phagocytes in host defense upon bacterial infection, we investigated the conditions necessary for induction of efficient phagocytic response together with the oxygen metabolism of the cells. The following evidence was found: (1) To induce efficient response of the phagocytes, physical impact of bacteria with the cells is required. (2) Neutrophils and probably macrophages as well generate superoxide anion as a primary product of the respiratory burst upon stimulation. Other active oxygen species including hydrogen peroxide seem to be formed within phagosomes. (3) A special cytochrome present in the membrane of phagocytes is probably involved in superoxide production.