Segal Anthony W
Center for Molecular Medicine, University College London, London WC1E 6JJ, United Kingdom.
Annu Rev Immunol. 2005;23:197-223. doi: 10.1146/annurev.immunol.23.021704.115653.
Neutrophils provide the first line of defense of the innate immune system by phagocytosing, killing, and digesting bacteria and fungi. Killing was previously believed to be accomplished by oxygen free radicals and other reactive oxygen species generated by the NADPH oxidase, and by oxidized halides produced by myeloperoxidase. We now know this is incorrect. The oxidase pumps electrons into the phagocytic vacuole, thereby inducing a charge across the membrane that must be compensated. The movement of compensating ions produces conditions in the vacuole conducive to microbial killing and digestion by enzymes released into the vacuole from the cytoplasmic granules.
中性粒细胞通过吞噬、杀灭和消化细菌及真菌,提供了先天性免疫系统的第一道防线。以往认为杀灭作用是由NADPH氧化酶产生的氧自由基和其他活性氧物质,以及髓过氧化物酶产生的氧化卤化物来完成的。我们现在知道这是不正确的。氧化酶将电子泵入吞噬泡,从而在膜上诱导出一种必须得到补偿的电荷。补偿离子的移动在泡内产生有利于微生物杀灭和被从细胞质颗粒释放到泡内的酶消化的条件。