Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, 110866, Shenyang, China.
Curr Stem Cell Res Ther. 2024;19(2):145-153. doi: 10.2174/1574888X18666230222124529.
is an intracellular bacterial pathogen capable of long-term persistence in the host, resulting in chronic infections in livestock and wildlife. The type IV secretion system (T4SS) is an important virulence factor of and is composed of 12 protein complexes encoded by the VirB operon. T4SS exerts its function through its secreted 15 effector proteins. The effector proteins act on important signaling pathways in host cells, inducing host immune responses and promoting the survival and replication of in host cells to promote persistent infection. In this article, we describe the intracellular circulation of -infected cells and survey the role of VirB T4SS in regulating inflammatory responses and suppressing host immune responses during infection. In addition, the important mechanisms of these 15 effector proteins in resisting the host immune response during infection are elucidated. For example, VceC and VceA assist in achieving sustained survival of in host cells by affecting autophagy and apoptosis. BtpB, together with BtpA, controls the activation of dendritic cells during infection, induces inflammatory responses, and controls host immunity. This article reviews the effector proteins secreted by T4SS and their involvement in immune responses, which can provide a reliable theoretical basis for the subsequent mechanism of hijacking the host cell signaling pathway by bacteria and contribute to the development of better vaccines to effectively treat bacterial infection.
是一种能够在宿主中长期潜伏的细胞内细菌病原体，导致牲畜和野生动物的慢性感染。IV 型分泌系统（T4SS）是 的一个重要毒力因子，由 VirB 操纵子编码的 12 个蛋白复合物组成。T4SS 通过其分泌的 15 种效应蛋白发挥作用。效应蛋白作用于宿主细胞中的重要信号通路，诱导宿主免疫反应，并促进 在宿主细胞中的存活和复制，以促进持续感染。本文描述了感染细胞的细胞内循环，并调查了 VirB T4SS 在感染过程中调节炎症反应和抑制宿主免疫反应中的作用。此外，还阐明了这 15 种效应蛋白在 感染过程中抵抗宿主免疫反应的重要机制。例如，VceC 和 VceA 通过影响自噬和细胞凋亡，协助 在宿主细胞中实现持续生存。BtpB 与 BtpA 一起在感染过程中控制树突状细胞的激活，诱导炎症反应，并控制宿主免疫。本文综述了 T4SS 分泌的效应蛋白及其在免疫反应中的作用，为随后细菌劫持宿主细胞信号通路的机制提供了可靠的理论依据，并有助于开发更好的疫苗来有效治疗 细菌感染。
