Functional characterization of the collagen-binding protein DIP2093 and its influence on host-pathogen interaction and arthritogenic potential of Corynebacterium diphtheriae

• Published in: Microbiology (Society for General Microbiology) Vol. 163; no. 5; pp. 692 - 701
• Main Authors: Peixoto, Renata Stavracakis, Antunes, Camila Azevedo, Lourêdo, Liliane Simpson, Viana, Vanilda Gonçalves, Santos, Cintia Silva Dos, Fuentes Ribeiro da Silva, Jemima, Hirata, Jr, Raphael, Hacker, Elena, Mattos-Guaraldi, Ana Luíza, Burkovski, Andreas
• Format: Journal Article
• Language: English
• Published: England 01-05-2017
• Subjects: Adhesins, Bacterial - genetics; Adhesins, Bacterial - metabolism; Animals; Arthritis - microbiology; Arthritis - pathology; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Caenorhabditis elegans - microbiology; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cell Line, Tumor; Collagen - metabolism; Corynebacterium diphtheriae - pathogenicity; Diphtheria - microbiology; Diphtheria - pathology; Epithelial Cells - microbiology; HeLa Cells; Host-Pathogen Interactions - physiology; Humans; Macrophages - microbiology; Mice; Protein Binding - physiology; RAW 264.7 Cells
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.000467

Corynebacterium diphtheriae is typically recognized as the a etiological agent of diphtheria, a toxaemic infection of the respiratory tract; however, both non-toxigenic and toxigenic strains are increasingly isolated from cases of invasive infections. The molecular mechanisms responsible for bacterial colonization and dissemination to host tissues remain only partially understood. In this report, we investigated the role of DIP2093, described as a putative adhesin of the serine-aspartate repeat (Sdr) protein family in host-pathogen interactions of C. diphtheriae wild-type strain NCTC13129. Compared to the parental strain, a DIP2093 mutant RN generated in this study was attenuated in its ability to bind to type I collagen, to adhere to and invade epithelial cells, as well as to survive within macrophages. Furthermore, DIP2093 mutant strain RN had a less detrimental impact on the viability of Caenorhabditis elegans as well as in the clinical severity of arthritis in mice. In conclusion, DIP2093 functions as a microbial surface component recognizing adhesive matrix molecules, and may be included among the factors that contribute to the pathogenicity of C. diphtheriae strains, independently of toxin production.