Released ATP is an extracellular cytotoxic mediator in salivary histatin 5-induced killing of Candida albicans
Released ATP is an extracellular cytotoxic mediator in salivary histatin 5-induced killing of Candida albicans
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DOI：
10.1128/iai.68.12.6848-6856.2000
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发表时间：
2000-12-01
影响因子：
3.1
通讯作者：
Edgerton, M
中科院分区：
文献类型：
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作者：
Koshlukova, SE;Araujo, MWB;Edgerton, M
唾液组蛋白 (Hsts) 是一种抗真菌肽，有望作为念珠菌病的治疗剂。 Hst 5 通过一种涉及在没有细胞溶解的情况下释放细胞 ATP 的机制杀死真菌病原体白色念珠菌。在这里，我们证明释放的 ATP 在 Hst 5 杀伤中具有进一步的作用。将细胞与 ATP 类似物一起孵育会诱导细胞死亡，并且添加 ATP 清除剂腺苷三磷酸双磷酸酶以去除 Hst 5 处理期间释放的细胞外 ATP，导致细胞杀伤减少。使用对 Hst 5 敏感性降低的厌氧生长的白色念珠菌进行的实验证实，由于 ATP 外流导致的细胞 ATP 消耗不足以导致细胞死亡。与 Hst 敏感的需氧培养物相反，厌氧生长的细胞不会被外源施加的 ATP 杀死。这些发现证实，Hst 结合、随后进入细胞以及 ATP 释放先于细胞毒性信号，而细胞毒性信号由细胞外 ATP 介导。在高等真核生物范例中，释放的 ATP 通过与膜核苷酸 P2X 受体结合而充当细胞毒性介质。基于药理学特征和对与 P2X(7) 受体抗体发生免疫反应的白色念珠菌 60 kDa 膜蛋白的检测，我们提出响应 Hst 5 释放的 ATP 会激活念珠菌 P2X(7) 样受体，导致细胞死亡。
Salivary histatins (Hsts) are antifungal peptides with promise as therapeutic agents against candidiasis. Hst 5 kills the fungal pathogen Candida albicans via a mechanism that involves release of cellular ATP in the absence of cytolysis. Here we demonstrate that released ATP has a further role in Hst 5 killing. Incubation of the cells with ATP analogues induced cell death, and addition of the ATP scavenger apyrase to remove extracellular ATP released during Hst 5 treatment resulted in a reduction in cell killing. Experiments using anaerobically grown C. albicans with decreased susceptibility to Hst 5 confirmed that depletion of cellular ATP as a result of ATP efflux was not sufficient to cause cell death. In contrast to Hst-susceptible aerobic cultures, anaerobically grown cells were not killed by exogenously applied ATP. These findings established that Hst binding, subsequent entry into the cells, and ATP release precede the signal for cytotoxicity, which is mediated by extracellular ATP. In a higher-eukaryote paradigm, released ATP acts as a cytotoxic mediator by binding to membrane nucleotide P2X receptors. Based on a pharmacological profile and detection of a C. albicans 60 kDa membrane protein immunoreactive with antibody to P2X(7) receptor, we propose that released ATP in response to Hst 5 activates candidal P2X(7)-like receptors to cause cell death.