Intracellular control of human neutrophil secretion. I. C5a-induced stimulus-specific desensitization and the effects of cytochalasin B.
Intracellular control of human neutrophil secretion. I. C5a-induced stimulus-specific desensitization and the effects of cytochalasin B.
复制标题
人中性粒细胞分泌的细胞内控制。
作者：
P. Henson;B. Zanolari;N. A. Schwartzman;S. Hong
当用细胞松弛素 B 预处理并用纯化的人 C5a 刺激时，人中性粒细胞释放颗粒成分髓过氧化物酶和溶菌酶，但不释放细胞质酶乳酸脱氢酶。然而，在细胞松弛素 B 之前先接触 C5a，会消除随后的分泌过程。中性粒细胞与 C5a 的相互作用被证明会导致浓度依赖性快速脱敏，这种脱敏不能通过随后添加细胞松弛素 B 或细胞松弛素 B 和 C5a 来克服。该效应是相对刺激特异性的，因为以这种方式脱敏的嗜中性粒细胞可以被酪蛋白或补体包被的酵母聚糖颗粒诱导释放颗粒酶。细胞松弛素 B 对中性粒细胞的影响似乎模仿可溶性刺激物（如 C5a 和免疫复合物）表面结合的影响。有人认为，脱敏与表面刺激相结合可能代表了限制中性粒细胞分泌的重要细胞内机制。
Human neutrophils released the granule constituents myeloperoxidase and lysozyme, but not the cytoplasmic enzyme lactic dehydrogenase, when pretreated with cytochalasin B and stimulated with purified human C5a. Prior exposure to C5a before the cytochalasin B, however, abrogated the subsequent secretory process. Interaction of neutrophils with C5a was shown to result in a concentration-dependent rapid desensitization that could not be overcome by later addition of cytochalasin B or of cytochalasin B and C5a. The effect was relatively stimulus specific in that neutrophils desensitized in this manner could be induced to release granule enzymes by casein or by complement-coated zymosan particles. Cytochalasin B effects on neutrophils appear to mimic those of surface binding of soluble stimuli such as C5a and immune complexes. It is suggested that desensitization in concert with surface stimulation may represent an important intracellular mechanism for limiting neutrophil secretion.