Human platelets efficiently kill IgG-opsonized E. coli.
Human platelets efficiently kill IgG-opsonized E. coli.
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DOI：
10.1111/j.1574-695x.2012.00945.x
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发表时间：
2012-06
影响因子：
--
通讯作者：
Worth RG
中科院分区：
文献类型：
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作者：
Riaz AH;Tasma BE;Woodman ME;Wooten RM;Worth RG
血小板是已知的止血贡献者，但最近被证明在炎症和传染病中很重要。此外，脓毒症患者经常观察到血小板减少症。我们之前报道过血小板主动吞噬 IgG 包被的乳胶珠。在当前的研究中，人类血小板参与宿主防御细菌感染的能力是通过评估其杀死大肠杆菌的能力来确定的。将洗涤的人血小板与未经调理的或经 IgG 调理的大肠杆菌一起孵育，并评估其对大肠杆菌的结合和杀灭作用。我们发现，尽管未调理和 IgG 调理的大肠杆菌均与血小板相关，但只有 IgG 调理的大肠杆菌被有效杀死，除非血小板被强效激动剂激活。杀菌活性依赖于 FcγRIIA，对细胞松弛素 D 敏感，但与活性氧代谢物无关。这些数据表明血小板可能在预防感染方面发挥重要作用。
Platelets are known contributors of hemostasis but have recently been shown to be important in inflammation and infectious diseases. Moreover, thrombocytopenia is often observed in patients with sepsis. We previously reported that platelets actively phagocytosed IgG-coated latex beads. In the current study, the capacity of human platelets to participate in host defense against bacterial infections was determined by assessing their ability to kill E. coli. Washed human platelets were incubated with unopsonized or IgG-opsonized E. coli and evaluated for binding and killing of E. coli. We found that although both unopsonized and IgG-opsonized E. coli associated with platelets, only IgG-opsonized E. coli were efficiently killed unless platelets were activated by a potent agonist. The bactericidal activity was dependent on FcγRIIA, was sensitive to cytochalasin D, but was not due to reactive oxygen metabolites. These data suggest that platelets may play an important role in protection against infection.