N-glycosylated proteins and distinct lipooligosaccharide glycoforms of Campylobacter jejuni target the human C-type lectin receptor MGL.
An increasing number of bacterial pathogens produce an array of glycoproteins of unknown function. Here we report that Campylobacter jejuni proteins that are modified by the N-linked glycosylation machinery encoded by the pgl locus bind the human Macrophage Galactose-type lectin (MGL). MGL receptor binding was abrogated by EDTA and N-acetylgalactosamine (GalNAc) and was successfully transferred to Escherichia coli by introducing the C. jejuni pgl locus together with a glycan acceptor protein. In addition to glycoproteins, C. jejuni lipooligosaccharide with a terminal GalNAc residue was recognized by MGL. Recombinant E. coli expressing the C. jejuni pgl locus in the absence of a suitable glycan acceptor protein produced altered lipopolysaccharide glycoforms that gained MGL reactivity. Infection assays demonstrated high levels of GalNAc-dependent interaction of the recombinant E. coli with MGL-transfected mammalian cells. In addition, interleukin-6 production by human dendritic cells was enhanced by C. jejuni lacking N-linked glycans compared with wild-type bacteria. Collectively, our results provide evidence that both N-linked glycoproteins and distinct lipooligosaccharide glycoforms of C. jejuni are ligands for the human C-type lectin MGL and that the C. jejuni N-glycosylation machinery can be exploited to target recombinant bacteria to MGL-expressing eukaryotic cells.
van Sorge
Nina M
NM
Department of Infectious Diseases and Immunology, Utrecht University, Utrecht, the Netherlands.
Bleumink
Nancy M C
NM
van Vliet
Sandra J
SJ
Saeland
Eirikur
E
van der Pol
W-Ludo
WL
van Kooyk
Yvette
Y
van Putten
Jos P M
JP
D000116:Acetylgalactosamine / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D016466:CHO Cells; D002169:Campylobacter Infections / Q000378:metabolism* / Q000382:microbiology; D016123:Campylobacter jejuni / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D006224:Cricetinae; D003412:Cricetulus; D003713:Dendritic Cells / Q000378:metabolism; D004492:Edetic Acid / Q000494:pharmacology; D004926:Escherichia coli / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D006031:Glycosylation; D054884:Host-Pathogen Interactions / Q000187:drug effects; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis; D037181:Lectins, C-Type / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
D001426:Bacterial Proteins; D002614:Chelating Agents; D006023:Glycoproteins; D015850:Interleukin-6; D037181:Lectins, C-Type; D008070:Lipopolysaccharides; C506225:MGL lectin, human; D011994:Recombinant Proteins; C023023:lipid-linked oligosaccharides; D004492:Edetic Acid; D000116:Acetylgalactosamine