Exocytosis of azurophil granule lumen proteins

Azurophil or primary granules were originally defined by their high content of myeloperoxidase (MPO) and their affinity for the basic dye azure A (Spicer & Hardin 1969). Azurophil granules are generally described as spherical. Like lysosomes, they contain CD63 in their membrane (Cham et al. 1994) but are regarded as specialized secretory granules rather than lysosomes (Cieutat et al. 1998). Azurophil granules undergo limited exocytosis in response to stimulation (Sengelov et al. 1993, Faurschou et al. 2002), their primary role is believed to be killing and degradation of engulfed microbes in the phagolysosome (Joiner et al. 1989).

MPO reacts with H2O2 formed by NADPH oxidase, increasing its toxicity by formation of hypochlorous acid and other chlorination products, tyrosine radicals and reactive nitrogen intermediates which attack the surface of microbes (Klebanoff et al. 2013).

嗜天青颗粒或初级颗粒最初被定义为富含髓过氧化物酶（MPO）及其对基本染料天青A（Spicer & Hardin，1969年）的亲和力。嗜天青颗粒通常被描述为球形。与溶酶体类似，它们在其膜中包含CD63（Cham等，1994年），但被视为特殊的分泌颗粒，而非溶酶体（Cieutat等，1998年）。嗜天青颗粒在受到刺激时仅发生有限的胞吐作用（Sengelov等，1993年，Faurschou等，2002年），其主要功能被认为是在吞噬溶酶体内杀死和降解吞噬的微生物（Joiner等，1989年）。髓过氧化物酶与由NADPH氧化酶形成的H2O2反应，通过形成次氯酸和其他氯化产物、酪氨酸自由基和活性氮中间体来增加其毒性，这些物质攻击微生物的表面（Klebanoff等，2013年）。