부산대학교 도서관

Summary The pathogenesis of non-typable Haemophilus influenzae disease begins with colonization of the nasopharynx and is facilitated by bacterial adherence to respiratory mucosa. The H. influenzae Hap autotransporter is a non-pilus adhesin that promotes adherence to epithelial cells and selected extracellular matrix proteins and mediates bacterial aggregation and microcolony formation. In addition, Hap has serine protease activity. Hap contains a 110 kDa internal passenger domain called HapS and a 45 kDa C-terminal translocator domain called Hapβ. In the present study, we sought to define the structural basis for Hap adhesive activities. Based on experiments using a panel of monoclonal antibodies against HapS , a deletion derivative lacking most of HapS and a purified fragment of HapS , we established that adherence to epithelial cells is mediated by sequences within the C-terminal 311 residues of HapS . In additional experiments, we discovered that bacterial aggregation is also mediated by sequences within the C-terminal 311 residues of HapS and occurs via HapS –HapS interaction between molecules on neighbouring organisms. Finally, we found that adherence to fibronectin, laminin and collagen IV is mediated in part by sequences within the C-terminal 311 residues of HapS and in full by sequences within the C-terminal 511 residues of HapS . Taken together, these results demonstrate that all Hap adhesive activities reside in the C-terminal portion of HapS . Coupled with earlier observations, the current results establish that HapS adhesive activities and HapS protease activity are contained in separate modules of the protein. [ABSTRACT FROM AUTHOR]