Microbial pathogens possess a diversity of weapons that disrupt host homeostasis and immune defenses, thus resulting in the establishment of infection. The best-characterized system mediating bacterial protein delivery into target eukaryotic cells is the type III secretion system (T3SS) expressed by Gram-negative bacteria, including the human enteric pathogens Shigella, Salmonella, Yersinia, and enteropathogenic/enterohemorragic Escherichia coli (EPEC/EHEC). The emerging global view is that these T3SS-bearing pathogens share similarities in their ability to target key cellular pathways such as the cell cytoskeleton, trafficking, cell death/survival, and the NF-κB and MAPK signaling pathways. In particular, multiple host proteins are targeted in a given pathway, and different T3SS effectors from various pathogens share functional similarities.

微生物病原体拥有各种各样的武器，可以破坏宿主体内的动态平衡和免疫防御，从而导致感染的建立。介导细菌蛋白传递到目标真核细胞中的最典型的系统是革兰氏阴性细菌表达的III型分泌系统（T3SS），包括人类肠道病原菌志贺氏菌，沙门氏菌，耶尔森氏菌和肠致病性/肠出血性大肠杆菌（EPEC / EHEC）。新兴的全球观点是，这些携带T3SS的病原体在靶向关键细胞途径（如细胞骨架，运输，细胞死亡/存活以及NF-κB和MAPK信号通路）的能力方面具有相似性。特别是，多种宿主蛋白​​以给定的途径为靶标，来自各种病原体的不同T3SS效应子具有功能相似性。