Sarwar J, Campagnari A A, Kirkham C, Murphy T F
Department of Medicine, School of Medicine and Biomedical Sciences, State University of New York, Buffalo.
Infect Immun. 1992 Mar;60(3):804-9. doi: 10.1128/iai.60.3.804-809.1992.
Branhamella catarrhalis is a common cause of otitis media in children and of respiratory infections in adults with chronic bronchitis. Little is known about the antigenic structure of the outer membrane proteins (OMPs). In this study, two murine monoclonal antibodies, 7D6 and 5E8, were developed and used to characterize the major heat-modifiable OMP (OMP C/D) of B. catarrhalis. Immunoblot assays indicated that OMP C/D is heat modifiable, having a molecular mass of 55 kDa at room temperature and a mass of 60 kDa when heated under reducing conditions. Expression of the epitopes is independent of growth phase and growth media. Both epitopes are present in 51 of 51 strains of B. catarrhalis tested and are highly specific for Branhamella strains, being absent from a variety of other gram-negative species. Antibody 5E8 recognizes an epitope which is expressed on the surface of the intact bacterium. We conclude that OMP C/D is a major, heat-modifiable OMP antigen that expresses at least one stable, conserved epitope on the surface of B. catarrhalis. Future studies should focus on the role of OMP C/D in pathogenesis and on its potential role as a vaccine antigen.
卡他布兰汉菌是儿童中耳炎以及患有慢性支气管炎的成年人呼吸道感染的常见病因。关于其外膜蛋白（OMPs）的抗原结构，人们了解甚少。在本研究中，制备了两种鼠单克隆抗体7D6和5E8，并用于鉴定卡他布兰汉菌主要的热可变OMP（OMP C/D）。免疫印迹分析表明，OMP C/D是热可变的，在室温下分子量为55 kDa，在还原条件下加热后分子量为60 kDa。表位的表达与生长阶段和生长培养基无关。在所检测的51株卡他布兰汉菌中，两种表位均存在，并且对布兰汉菌菌株具有高度特异性，在多种其他革兰氏阴性菌中不存在。抗体5E8识别完整细菌表面表达的一个表位。我们得出结论，OMP C/D是一种主要的、热可变的OMP抗原，在卡他布兰汉菌表面表达至少一种稳定的、保守的表位。未来的研究应聚焦于OMP C/D在发病机制中的作用及其作为疫苗抗原的潜在作用。
