DAMAGE TO CANDIDA-ALBICANS HYPHAE AND PSEUDOHYPHAE BY THE MYELOPEROXIDASE SYSTEM AND OXIDATIVE PRODUCTS OF NEUTROPHIL METABOLISM INVITRO
DAMAGE TO CANDIDA-ALBICANS HYPHAE AND PSEUDOHYPHAE BY THE MYELOPEROXIDASE SYSTEM AND OXIDATIVE PRODUCTS OF NEUTROPHIL METABOLISM INVITRO
复制标题
DOI：
10.1172/jci109958
复制
发表时间：
1980-01-01
影响因子：
15.9
通讯作者：
HAUDENSCHILD, CC
中科院分区：
文献类型：
--
作者：
DIAMOND, RD;CLARK, RA;HAUDENSCHILD, CC
通过抑制[14 C]胞嘧啶摄取来测量对菌丝的损伤量。4例慢性肉芽肿病患者中只有1例的中性粒细胞完全破坏菌丝。从这个单一的病人中性粒细胞破坏菌丝远不如同时测试正常对照组的中性粒细胞有效。2例遗传性髓过氧化物酶缺乏症患者的中性粒细胞均未破坏菌丝。这证实了氧化机制的重要性，一般和髓过氧化物酶介导的系统，特别是在破坏念珠菌菌丝。几种潜在的杀真菌氧化中间体是由正常中性粒细胞的代谢途径产生的，但它们对念珠菌菌丝的相对毒性以前是未知的。为了帮助确定这一点，使用无细胞体外系统来产生这些潜在的杀微生物产物。髓过氧化物酶与H_2O_2、碘化物和氯化物联用11次试验，对菌丝接种物的损伤率达91.2%。当省略氯化物或碘化物时，损伤较小，当省略髓过氧化物酶或通过加热灭活髓过氧化物酶时，没有损伤。叠氮化物、氰化物和过氧化氢酶（但不包括加热过氧化氢酶）抑制损伤。H_2O_2的产生系统可以取代髓过氧化物酶系统中的试剂H_2O_2。这些包括葡萄糖氧化酶，在葡萄糖的存在下，和黄嘌呤氧化酶，在次黄嘌呤或乙醛的存在下。在髓过氧化物酶和卤化物的存在下，黄嘌呤氧化酶系统的毒性不受超氧化物歧化酶的抑制，在某些条件下，这种酶略有增加。超氧自由基可能不会直接损害菌丝，但主要作为H2 O2产生的中间体。利用玫瑰红的光活化作用研究了单线态氧对菌丝的可能损伤。这种染料在光和氧气存在下破坏菌丝。这种效应几乎完全被假定的单线态氧猝灭剂：组氨酸，色氨酸和1，4-二氮杂双环[2.2.2]辛烷抑制。这些试剂抑制髓过氧化物酶、卤化物和H2 O2或过氧化物源（黄嘌呤氧化酶加乙醛）对菌丝的损伤。髓过氧化物酶介导的损伤菌丝抑制二甲基亚砜，抗氧化剂和清除剂的羟基自由基。参与氧化机制，髓过氧化物酶-H2 O2-卤化物系统，特别是在体外，也许在体内破坏菌丝以及支持。
Amount of damage to hyphae was measured by inhibition of [14C]cytosine uptake. Neutrophils from only 1 of 4 patients with chronic granulomatous disease damaged hyphae at all. Neutrophils from this single patient damaged hyphae far less efficiently than simultaneously tested neutrophils from normal control subjects. Neutrophils from neither of 2 subjects with hereditary myeloperoxidase deficiency damaged the hyphae. This confirmed the importance of oxidative mechanisms in general and myeloperoxidase-mediated systems in particular in damaging Candida hyphae. Several potentially fungicidal oxidative intermediates are produced by metabolic pathways of normal neutrophils but their relative toxicity for Candida hyphae was previously unknown. To help determine this, cell-free in vitro systems were used to generate these potentially microbicidal products. Myeloperoxidase with H2O2, iodide and chloride resulted in 91.2% damage to hyphal inocula in 11 experiments. There was less damage when chloride or iodide was omitted and no damage when myeloperoxidase was omitted or inactivated by heating. Azide, cyanide and catalase (but not heated catalase) inhibited the damage. Systems for generation of H2O2 could replace reagent H2O2 in the myeloperoxidase system. These included glucose oxidase, in the presence of glucose, and xanthine oxidase, in the presence of hypoxanthine or acetaldehyde. In the presence of myeloperoxidase and a halide, the toxicity of the xanthine oxidase system was not inhibited by superoxide dismutase and under some conditions was marginally increased by this enzyme. Superoxide radical probably did not damage hyphae directly but served primarily as an intermediate in the production of H2O2. The possible damage to hyphae by singlet oxygen was examined using photoactivation of rose bengal. This dye damaged hyphae in the presence of light and oxygen. The effect was almost completely inhibited by putative quenchers of singlet oxygen: histidine, tryptophan and 1,4-diazobicyclo[2.2.2]octane. These agents inhibited damage to hyphae by myeloperoxidase, halide and H2O2 or a peroxide source (xanthine oxidase plus acetaldehyde). Myeloperoxidase-mediated damage to hyphae was inhibited by dimethylsulfoxide, an antioxidant and scavenger of the hydroxyl radical. The involvement of oxidative mechanisms, and the myeloperoxidase-H2O2-halide system in particular, in damaging hyphae in vitro and perhaps in vivo as well is supported.