Bakaletz L O, Barenkamp S J
Department of Otolaryngology, Ohio State University College of Medicine, Columbus.
Infect Immun. 1994 Oct;62(10):4460-8. doi: 10.1128/iai.62.10.4460-4468.1994.
A family of high-molecular-weight (HMW) surface-exposed proteins important in the attachment of nontypeable Haemophilus influenzae (NTHi) to human epithelial cells was previously identified (J. W. St. Geme III, S. Falkow, and S. J. Barenkamp, Proc. Natl. Acad. Sci. USA 90:2875-2879, 1993). In the present investigation, indirect immunogold labeling and electron microscopy were used to localize these proteins on three clinical isolates of NTHi, mutants deficient in expression of one or both HMW proteins, and embedded sections of human oropharyngeal cells after incubation with NTHi strain 12. The filamentous material comprising the proteins was labeled with monoclonal antibodies directed against two prototype HMW proteins (HMW1 and HMW2) of prototype NTHi strain 12. Gold labeling was observed as a cap or discrete aggregate off one pole or centrally along one long axis of the bacterial cell. Heavily labeled, non-bacterial-cell-associated, disk-like aggregates of the HMW proteins were frequently noted in both bacterial preparations as well as in association with the oropharyngeal cell surface and intracellularly. Mutants demonstrated diminished labeling or an absence thereof, respectively, which correlated well with their previously demonstrated reduced ability or inability to adhere to Chang conjunctival epithelial cells in vitro. The Haemophilus HMW proteins share antigenic determinants with and demonstrate amino acid sequence similarity to the filamentous hemagglutinin protein of Bordetella pertussis, a critical adhesin of that organism. The studies presented here demonstrate that the Haemophilus proteins and B. pertussis filamentous hemagglutinin show impressive morphologic and perhaps additional functional similarity.
先前已鉴定出一类在不可分型流感嗜血杆菌（NTHi）与人上皮细胞黏附中起重要作用的高分子量（HMW）表面暴露蛋白（J. W. St. Geme III、S. Falkow和S. J. Barenkamp，《美国国家科学院院刊》90:2875 - 2879，1993年）。在本研究中，使用间接免疫金标记和电子显微镜将这些蛋白定位在三株NTHi临床分离株、一种或两种HMW蛋白表达缺陷的突变体以及与NTHi菌株12孵育后的人口咽细胞包埋切片上。用针对原型NTHi菌株12的两种原型HMW蛋白（HMW1和HMW2）的单克隆抗体标记构成这些蛋白的丝状物质。观察到金标记呈帽状或离散聚集体，位于细菌细胞的一极或沿细菌细胞一个长轴的中央。在细菌制剂以及与口咽细胞表面和细胞内相关联的情况下，经常注意到HMW蛋白大量标记的、与细菌细胞无关的盘状聚集体。突变体分别表现出标记减少或无标记，这与其先前证明的体外黏附到张氏结膜上皮细胞的能力降低或丧失密切相关。流感嗜血杆菌HMW蛋白与百日咳博德特氏菌的丝状血凝素蛋白具有共同的抗原决定簇，并在氨基酸序列上具有相似性，百日咳博德特氏菌的丝状血凝素蛋白是该菌的一种关键黏附素。此处呈现的研究表明，流感嗜血杆菌蛋白和百日咳博德特氏菌丝状血凝素显示出令人印象深刻的形态学以及可能的其他功能相似性。
