Håkansson A, Carlstedt I, Davies J, Mossberg A K, Sabharwal H, Svanborg C
Department of Medical Microbiology, Lund University, Sweden.
Am J Respir Crit Care Med. 1996 Oct;154(4 Pt 2):S187-91. doi: 10.1164/ajrccm/154.4_Pt_2.S187.
Haemophilus influenzae and Streptococcus pneumoniae are common causes of respiratory tract infections. H. influenzae attach to receptor epitopes in mucins and in epithelial cell membranes. Attachment is followed by an epithelial cell cytokine response. Secreted cytokines then initiate inflammation, upset the integrity of the mucosal barrier, and lead to disease. S. pneumoniae do not bind to mucins but attach to respiratory tract epithelial cells. Attachment is increased by viral infection of the epithelial cells. Unlike H. Influenzae, S. pneumoniae induce apoptosis in epithelial cells, thus disrupting the mucosal barrier. Attachment and persistence is counterbalanced by antiadhesive as well as bactericidal molecules in secretions such as human milk. These examples illustrate the balance between host defenses and microbial virulence as it has coevolved to maintain the health of the respiratory mucosa.
流感嗜血杆菌和肺炎链球菌是呼吸道感染的常见病因。流感嗜血杆菌附着于黏蛋白和上皮细胞膜中的受体表位。附着之后会引发上皮细胞的细胞因子反应。分泌的细胞因子随后引发炎症，破坏黏膜屏障的完整性，并导致疾病。肺炎链球菌不与黏蛋白结合，但附着于呼吸道上皮细胞。上皮细胞的病毒感染会增加其附着。与流感嗜血杆菌不同，肺炎链球菌会诱导上皮细胞凋亡，从而破坏黏膜屏障。附着和持续存在会被诸如人乳等分泌物中的抗黏附分子以及杀菌分子所抵消。这些例子说明了宿主防御与微生物毒力之间的平衡，这种平衡是在共同进化过程中形成的，以维持呼吸道黏膜的健康。
