Such reactive oxygen intermediates (ROIs) as superoxide anion (O20 and hydrogen peroxide (H2O2) interact to produce hydroxyl radical (OH0, an extremely potent oxidant that is known to be important for the bactericidal activity. the ROIs might be
harmful
to immunocytes as well as microbes. Released O2 or H2O2 may participate in damage to surrounding tissue and other blood cells.
In this study the author examinend the production of O2 from resident murine peritoneal macrophages, peritoneal macrophages elicited with thioglycollate, or peritoneal macrophages activated with BCG in vivo. The author also observed the
triggering
effects of such cytokines as interleukin-1α, interleukin-8, interferon-γ and tumor necrosis factor-α, and such biolgical response modifiers (BRMs) as polyinosinic polycytilidic acid, lipopolysaccharide and
N-formyl-methionyl-leucyl-phenylalanine.
The priming effects of the same cytokines and BRMs on the production of ROIs were observed after incubation of the murine peritonal macrophages with each cytokine or BRM for 2 hours and then triggered with phorbol myristate acetate (PMA).
Superoxide
anion productions by thioglycollate-elicited and BCG-activated peritoneal macrophages were higher than those by resident peritoneal macrophages. Of the various cytokines, only γ-IFN triggered the producton of O2 from resident,
thioglycollate-elicited
and BCG-activated peritoneal macrophages. When the macrophages were triggered with PMA after 2 hours incubation with each cytokine, only resident peritoneal macrophages had been stimulated to produce more ROIs than those that had not been
incubated
with
cytokine.
These results show that in vivo stinrlation of peritoneal macrophages might desensitize the cells in case of the procuction of ROIs. This fact can be used for the detection of macrophage activation in vivo by systemic infection with microbes.
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