Infection-associated decline of cape buffalo blood catalase augments serum trypanocidal activity.
Infection-associated decline of cape buffalo blood catalase augments serum trypanocidal activity.
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感染相关的水牛血过氧化氢酶下降增强了血清杀锥虫活性。
DOI：
10.1128/iai.67.6.2797-2803.1999
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发表时间：
1999
影响因子：
3.1
通讯作者：
Black,SJ
中科院分区：
文献类型：
--
作者：
Wang,Q;Murphy,N;Black,SJ
从受感染的水牛血液中清除锥虫与两种反应的发展有关：(i)补体依赖性和克隆特异性裂解活性；（ii）不受锥虫克隆或物种限制的补体非依赖性锥虫杀灭活性。后一种活性由h2o2介导，需要血清中黄嘌呤氧化酶的存在，而不需要嘌呤底物的加入。黄嘌呤氧化酶依赖的锥虫活性在水牛血清中的表达与h2o2分解代谢活性的下降是一致的，并且是必需的。水牛血清的h2o2分解代谢活性完全是由过氧化氢酶引起的，当锥虫从血液中清除时，过氧化氢酶活性下降了8倍，同时红细胞相关过氧化氢酶活性下降了5倍。开普水牛没有发展出随后的寄生波。在同样感染的牛中，寄生虫病的清除也与锥虫克隆特异性裂解活性的发展有关，但与血清中h2o2依赖性锥虫活性的获得无关，并且牛支持复发性寄生虫病。牛感染前和感染后血清缺乏锥虫活性是由于黄嘌呤氧化酶含量低和过氧化氢酶活性持续。这些数据有力地表明，感染诱导的血清氧化反应（其功效因血液过氧化氢酶的下降而被放大）有助于抑制水牛寄生虫病的复发。
Clearance of trypanosomes from the blood of infected Cape buffalo was associated with the development of two responses: (i) complement-dependent and clone-specific lytic activity and (ii) complement-independent trypanocidal activity that was not restricted by trypanosome clone or species. This latter activity was mediated by H2O2and required the presence of xanthine oxidase in serum but not the addition of purine substrates. Expression of the xanthine oxidase-dependent trypanocidal activity in Cape buffalo serum was coincident with, and required, a decline in its H2O2catabolic activity. The H2O2catabolic activity of Cape buffalo serum was due solely to catalase and declined by eightfold around the time that trypanosomes were cleared from the blood, accompanied by a fivefold drop in erythrocyte-associated catalase activity. The Cape buffalo did not develop subsequent parasitemic waves. Clearance of parasitemia in similarly infected cattle was also associated with development of trypanosome clone-specific lytic activity, but not with the acquisition of H2O2-dependent trypanocidal activity in serum, and the cattle supported recurring parasitemia. The lack of trypanocidal activity in pre- and postinfection cattle sera was due to their low content of xanthine oxidase and sustained catalase activity. These data strongly suggest that an infection-induced serum oxidative response, the efficacy of which is amplified by a decline in blood catalase, contributes to suppression of recurring parasitemia in Cape buffalo.