Avadhanula Vasanthi, Wang Yan, Portner Allen, Adderson Elisabeth
Department of Molecular Sciences, University of Tennessee Health Sciences Center, Memphis, TN 38163, USA.
Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
J Med Microbiol. 2007 Sep;56(Pt 9):1133-1137. doi: 10.1099/jmm.0.47086-0.
Respiratory syncytial virus (RSV) infection is associated with secondary bacterial infections caused by nontypeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae. The pathogenesis of these complications is not completely understood; however, viral infection of respiratory epithelial cells promotes colonization by these bacteria. In the present study, RSV virions associated with NTHi and pneumococci in an inoculum-dependent manner in a fluid-phase binding assay. Adherence of NTHi and S. pneumoniae to epithelial cells transiently expressing RSV G glycoprotein was 2- and 2.2-fold higher, respectively, than adhesion to cells transfected with the vector alone (P <0.01). Furthermore, 4.6- and 6.2-fold larger numbers of NTHi and pneumococci bound to cells expressing a membrane-bound full-length RSV G protein than to cells expressing a truncated non-membrane-bound protein (P <or=0.005). Pre-incubating cells expressing membrane-bound G protein with blocking anti-RSV G antibodies reduced bacterial adherence by 78-84 % (P <or=0.005). These studies demonstrate that RSV G protein is a receptor for both NTHi and S. pneumoniae. Strategies to prevent this interaction may reduce the incidence of secondary bacterial complications of RSV infection.
呼吸道合胞病毒（RSV）感染与由不可分型流感嗜血杆菌（NTHi）和肺炎链球菌引起的继发性细菌感染有关。这些并发症的发病机制尚未完全明了；然而，呼吸道上皮细胞的病毒感染会促进这些细菌的定植。在本研究中，在液相结合试验中，RSV病毒粒子以接种物依赖的方式与NTHi和肺炎球菌相关联。NTHi和肺炎链球菌对瞬时表达RSV G糖蛋白的上皮细胞的黏附分别比单独转染载体的细胞高2倍和2.2倍（P<0.01）。此外，与表达截短的非膜结合蛋白的细胞相比，结合到表达膜结合全长RSV G蛋白的细胞上的NTHi和肺炎球菌数量分别多4.6倍和6.2倍（P≤0.005）。用阻断性抗RSV G抗体预孵育表达膜结合G蛋白的细胞可使细菌黏附减少78-84%（P≤0.005）。这些研究表明，RSV G蛋白是NTHi和肺炎链球菌的受体。预防这种相互作用的策略可能会降低RSV感染继发性细菌并发症的发生率。
