van Ham S M, van Alphen L, Mooi F R, van Putten J P
Abteilung Infektionsbiologie, Max-Planck-Institut für Biologie, Tübingen, Germany.
Infect Immun. 1995 Dec;63(12):4883-9. doi: 10.1128/iai.63.12.4883-4889.1995.
Fimbriae are colonization factors of the human pathogen Haemophilus influenzae in that they mediate bacterial adherence to human eukaryotic cells. The contribution of the major (HifA) and putative minor (HifD and HifE) subunits of H. influenzae fimbriae to fimbria-specific adherence was studied by using mutants that were inactivated in distinct fimbrial genes. Both the major and minor subunits were required for adherence of H. influenzae to oropharyngeal epithelial cells and human erythrocytes carrying the AnWj antigen. Cloning of defined H. influenzae fimbrial genes in an Escherichia coli strain with type 1 fimbriae yielded recombinants expressing high amounts of HifA-containing H. influenzae fimbriae either with or without coexpression of both H. influenzae minor subunits. Both clones exhibited the specific adherence properties of H. influenzae fimbriae, implying that the minor H. influenzae subunits are dispensable for adherence and that the adhesive domain resides in the major subunit, HifA. In H. influenzae itself, the minor subunits probably affect adherence by raising the number of fimbriae above the minimal level required to establish adherence.
菌毛是人类病原体流感嗜血杆菌的定植因子，因为它们介导细菌与人真核细胞的黏附。通过使用在不同菌毛基因中失活的突变体，研究了流感嗜血杆菌菌毛的主要亚基（HifA）和假定的次要亚基（HifD和HifE）对菌毛特异性黏附的贡献。主要亚基和次要亚基都是流感嗜血杆菌黏附口咽上皮细胞和携带AnWj抗原的人类红细胞所必需的。将特定的流感嗜血杆菌菌毛基因克隆到具有1型菌毛的大肠杆菌菌株中，产生了重组体，这些重组体表达了大量含HifA的流感嗜血杆菌菌毛，无论是否共表达两种流感嗜血杆菌次要亚基。两个克隆都表现出流感嗜血杆菌菌毛的特异性黏附特性，这意味着流感嗜血杆菌次要亚基对于黏附是可有可无的，并且黏附结构域位于主要亚基HifA中。在流感嗜血杆菌自身中，次要亚基可能通过将菌毛数量提高到建立黏附所需的最低水平以上来影响黏附。
