肺炎链球菌粘附肺Ⅱ型上皮细胞触发宿主细胞酪氨酸蛋白磷酸化

目的 探讨细胞内信号传导与肺炎球菌侵袭、致病的关系，在体外研究Ⅱ型肺炎链球菌粘附肺Ⅱ型上皮细胞（A549）是否能触发细胞内酪氨酸蛋白激酶（TPK）信号传导途径 ，以及触发该信号传导可能的细菌亚组分。方法 用FTTC荧光标记肺炎链球菌，在体外观察肺炎链球菌粘附肺Ⅱ型上皮细胞的粘附动力学特征；用免疫组织化学和ELISA方法观察完整细菌触发的细胞内酪氨酸蛋白磷酸化，用各种因素预处理肺炎链球菌后，观察触发细胞内酪氨酸蛋白磷酸化可能的细菌亚组分。结果 证实了上述粘附过程存在剂量依赖和时间的依赖关系，而且是特异的过程；细菌粘附使细胞内酪氨酸磷酸化由细菌表面蛋白质介导。结论 肺炎链球菌粘附肺Ⅱ型上皮细胞能触发细胞内信号传导，且细菌表面蛋白质在触发胞内酪氨酸蛋白磷酸化传导中起着重要作用。

Attachment of Streptococcus pneumoniae to A549 cells induces tyrosine phosphorylation of host cell proteins

Objective　To investigate the potentiality of adhesion of S. pn to type Ⅱ pneumocyte (A549) in inducing tyrosine phosphorylation of A549 cell proteins and the function subcomponents involved in. Methods　Labelled S. pn with FITC for the observation of kinetic characters of adhesion in vitro; The tyrosine phosphorylation of A549 cell proteins induced by S. pn was examined by immunohistochemistry and ELISA. Results　The adhesion of S. pn to A549 cells was in a time-and dose-dependent fashion suggesting the specific interaction; Tyrosine phosphorylation induced by adhesion was dose-and time-dependent and was mediated by the surface proteins of S. pn. Conclusion　S. pn adheres to A549 cells and triggers the signal cascade in which the surface proteins of S. pn play a vital role.