We investigated the effect of bovine lactoferricin (Lfcin-B), a peptide derived from bovine lactoferrin, on activation of intestinal epithelial cells in IEC-6 intestinal cell, and protection against rotavirus (RV) infection in in vivo. Treatment with Lfcin-B significantly enhanced the growth of IEC-6 cells, and increased the capacity of cell attachment and spreading of the cells to culture plates. Also, Lfcin-B synergistically augmented the binding of IEC-6 cells to laminin, a component of extracellular matrix (ECM). In the analysis of the intracellular mechanism related to Lfcin-B-induced activation of IEC-6 cells, this peptide up-regulated tyrosine-dependent phosphorylation of focal adhesion kinase (FAK) and paxillin, which were intracellular proteins associated with cell adhesion, spreading and signal transduction during cell activation. An experiment using synthetic peptides with various sequences of amino acids revealed that a sequence of 9 amino acids (FKCRRWQWR) corresponding to 17-25 of the N-terminus of Lfcin-B is responsible for the epithelial cell activation. In an in vivo experiments, treatment with Lfcin-B one day before RV infection effectively prevented RV-induced diarrhea, and significantly reduced RV titers in the bowels of infected mice. These results suggest that Lfcin-B serve meaningful roles in maintenance and repair of intestinal mucosal tissues, and in protection against intestinal infection by RV. Collectively, Lfcin-B is a promising candidate applicable to drugs or functional foods beneficial for the health of the intestines and mucosal immunity.

中文翻译：

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牛乳铁蛋白通过 FAK 和桩蛋白的磷酸化诱导肠上皮细胞活化并预防轮状病毒感染。

我们研究了牛乳铁蛋白 (Lfcin-B)（一种源自牛乳铁蛋白的肽）对 IEC-6 肠细胞中​​肠上皮细胞活化的影响，以及体内对轮状病毒 (RV) 感染的保护作用. 用 Lfcin-B 处理显着增强了 IEC-6 细胞的生长，并增加了细胞附着和细胞向培养板扩散的能力。此外，Lfcin-B 协同增强 IEC-6 细胞与层粘连蛋白（细胞外基质 (ECM) 的一种成分）的结合。在与 Lfcin-B 诱导的 IEC-6 细胞激活相关的细胞内机制分析中，该肽上调粘着斑激酶 (FAK) 和桩蛋白的酪氨酸依赖性磷酸化，它们是与细胞粘附相关的细胞内蛋白，扩散和细胞活化过程中的信号转导。使用具有各种氨基酸序列的合成肽进行的实验表明，对应于 Lfcin-B N-末端的 17-25 位的 9 个氨基酸序列 (FKCRRWQWR) 负责上皮细胞活化。在一个在体内实验中，RV 感染前一天用 Lfcin-B 治疗有效地预防了 RV 引起的腹泻，并显着降低了感染小鼠肠道中的 RV 滴度。这些结果表明，Lfcin-B 在维持和修复肠粘膜组织以及防止 RV 引起的肠道感染方面发挥着重要作用。总的来说，Lfcin-B 是一种很有前途的候选药物，适用于有益于肠道健康和粘膜免疫的药物或功能性食品。