Role of cell-generated hydrogen peroxide in granulocyte-mediated killing of schistosomula of Schistosoma mansoni in vitro.
Role of cell-generated hydrogen peroxide in granulocyte-mediated killing of schistosomula of Schistosoma mansoni in vitro.
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DOI：
10.1172/jci110037
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
J. Kazura;M. Fanning;J. Blumer;A. Mahmoud
中科院分区：
文献类型：
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作者：
J. Kazura;M. Fanning;J. Blumer;A. Mahmoud
人类和鼠类粒细胞已被证明可以杀死蠕虫寄生虫的幼虫阶段；然而，人们对这种细胞介导的细胞毒性的机制知之甚少。本研究旨在评估过氧化过程在体外人粒细胞杀死曼氏血吸虫血吸虫中的作用。单独与血吸虫一起孵育或在特定抗体或补体存在下，测量人嗜中性粒细胞、嗜酸性粒细胞和嗜碱性粒细胞产生 H(2)O(2) 的速率。调理寄生虫（抗体和/或补体）使嗜中性粒细胞、嗜酸性粒细胞和嗜碱性粒细胞产生 H(2)O(2) 的速率分别增加 500、500 和 371。 H(2)O(2) 释放速率与粒细胞数量和附着在血吸虫表面的细胞比例直接相关。孵育 10 分钟时过氧化氢释放量增加，并且在向血吸虫添加白细胞后 16 小时内即可证实。发现这种氧产物的主要来源是粘附在血吸虫上的粒细胞，而不是那些未附着的粒细胞。嗜中性粒细胞和嗜酸性粒细胞产生的过氧化氢在数量上相似（用抗体和补体包被的血吸虫刺激5 x 10(6) 嗜中性粒细胞和嗜酸性粒细胞以分别0.35和0.40 nmol/min的速率释放H(2)O(2)。粒细胞介导的寄生虫杀灭作用与 H(2)O(2) 生成率相关；这两个过程都被过氧化氢酶抑制。为了进一步确定氧化代谢物的作用，使用了两名患有慢性肉芽肿病的受试者的中性粒细胞和嗜酸性粒细胞；观察到粒细胞介导的寄生虫死亡率显着降低。 H(2)O(2) 介导的杀伤需要过氧化物酶。在中性粒细胞血吸虫混合物中添加过氧化物酶抑制剂叠氮化物 (1 mM)、氰化物 (1 mM) 或氨基三唑 (1 cM) 可显着降低寄生虫细胞毒性 (P < 0.01)；当使用嗜酸性粒细胞时观察到类似的减少（P < 0.01）。在粒细胞、调理素和寄生虫存在的情况下，证明了卤化物（碘化物）与三氯乙酸可沉淀蛋白质（2.4-6.0 nmol/h/10(7) 中性粒细胞）的固定；该过程被 1 mM 叠氮化物完全抑制。这些数据表明，人粒细胞和血吸虫表面之间的接触导致细胞过氧化氢和碘化的释放。 H(2)O(2) 的产生及其与过氧化物酶的相互作用似乎对于影响体外粒细胞介导的寄生虫细胞毒性至关重要。
Human as well as murine granulocytes have been shown to kill the larval stages of helminth parasites; the mechanism of this cell-mediated cytotoxicity is, however, poorly understood. The present study was designed to assess the role of peroxidative processes in killing of schistosomula of Schistosoma mansoni by human granulocytes in vitro. The rate of H(2)O(2) production by human neutrophils, eosinophils, and basophils was measured upon incubation with schistosomula alone or in the presence of specific antibody or complement. Opsonized parasites (antibody and/or complement) increased the rate of H(2)O(2) production by neutrophils, eosinophils, and basophils by respective percentages of 500, 500, and 371. The rate of H(2)O(2) release was directly related to the number of granulocytes and to the proportion of cells attached to the surface of the schistosomula. Increased hydrogen peroxide release occurred by 10 min of incubation and was demonstrable up to 16 h after addition of leukocytes to schistosomula. The primary source of this oxygen product was found to be the granulocytes adherent to the schistosomula and not those that remained unattached. Hydrogen peroxide production by neutrophils and eosinophils was quantitatively similar (schistosomula coated with antibody plus complement stimulated 5 x 10(6) neutrophils and eosinophils to release H(2)O(2) at respective rates of 0.35 and 0.40 nmol/min). Granulocyte-mediated parasite killing correlated with rate of H(2)O(2) generation; both processes were inhibited by catalase. To define further the role of oxidative metabolites, neutrophils and eosinophils of two subjects with chronic granulomatous disease were used; marked reduction of granulocyte-mediated parasite mortality was observed. Peroxidase was required for H(2)O(2)-mediated killing. Addition of the peroxidase inhibitors azide (1 mM), cyanide (1 mM), or aminotriazole (1 cM) to neutrophilschistosomula mixtures significantly reduced parasite cytotoxicity (P < 0.01); similar reduction was observed when eosinophils were used (P < 0.01). Fixation of halide (iodide) to trichloroacetic acid-precipitable protein (2.4-6.0 nmol/h per 10(7) neutrophils) was demonstrated in the presence of granulocytes, opsonins, and parasites; this process was completely inhibited by 1 mM azide. These data indicate that contact between the surfaces of human granulocytes and schistosomula results in release of cellular hydrogen peroxide and iodination. The generation of H(2)O(2) and its interaction with peroxidase appear to be crucial in effecting in vitro granulocyte-mediated parasite cytotoxicity.