title: The C-type lectin-like domain containing proteins Clec-39 and Clec-49 are crucial for Caenorhabditis elegans immunity against Serratia marcescens infection.
abstract: Caenorhabditis elegans exhibits protective immunity against a variety of fungal and bacterial pathogens. Since C. elegans lacks an adaptive immune system, pathogen recognition is mediated entirely by innate immunity. To date, little is known about the involvement of pattern recognition receptors (PRRs) in pathogen sensing as part of the C. elegans immunity. C-type lectin-like domain (CTLD) containing proteins represent a superfamily of PRRs. A large number of genes encoding for CTLD proteins are present in the C. elegans genome, however the role of CTLD proteins in bacterial recognition and antibacterial immunity has not yet been determined. In this study, we investigated the function of selected C. elegans CTLD proteins during infection with the Gram-negative bacterium Serratia marcescens. Wild-type and CTLD gene-deficient C. elegans strains were compared in their susceptibility to S. marcescens infection. Interestingly, survival and egg laying were significantly reduced in strains deficient for clec-39 and clec-49 indicating a role for both CTLD proteins in C. elegans immune defense against bacteria as evidenced by using S. marcescens infection. Binding studies with recombinantly expressed Clec-39-Fc and Clec-49-Fc fusion proteins revealed that both CTLD proteins recognized live bacteria in a Ca(2+)-independent manner. This study provides insight into the role of CTLD proteins in C. elegans immunity and demonstrates their function during bacterial infection.
authors.affiliation: Max Planck Institute of Colloids and Interfaces, Department of Biomolecular Systems, Am Mühlenberg 1, 14476 Potsdam, Germany.
authors.forename: S M
authors.initials: SM
authors.lastname: Miltsch
authors.affiliation: Max Planck Institute of Colloids and Interfaces, Department of Biomolecular Systems, Am Mühlenberg 1, 14476 Potsdam, Germany; Freie Universität Berlin, Institute of Chemistry and Biochemistry, Arnimallee 22, 14195 Berlin, Germany.
authors.forename: P H
authors.initials: PH
authors.lastname: Seeberger
authors.affiliation: Max Planck Institute of Colloids and Interfaces, Department of Biomolecular Systems, Am Mühlenberg 1, 14476 Potsdam, Germany; Freie Universität Berlin, Institute of Chemistry and Biochemistry, Arnimallee 22, 14195 Berlin, Germany. Electronic address: Bernd.Lepenies@mpikg.mpg.de.
authors.forename: B
authors.initials: B
authors.lastname: Lepenies
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D029742:Caenorhabditis elegans Proteins / Q000502:physiology*; D055786:Gene Knockout Techniques; D054884:Host-Pathogen Interactions; D006801:Humans; D007113:Immunity, Innate; D037181:Lectins, C-Type / Q000502:physiology*; D011485:Protein Binding; D012706:Serratia marcescens / Q000502:physiology*
chemical_list: C000593287:CLEC-39 protein, C elegans; C000593288:CLEC-49 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D037181:Lectins, C-Type
keywords: C-type lectins; C. elegans; Carbohydrates; Host–pathogen interaction; Innate immunity