C-terminal repeats of Clostridium difficile toxin A induce production of chemokine and adhesion molecules in endothelial cells and promote migration of leukocytes.
The C-terminal repeating sequences of Clostridium difficile toxin A (designated ARU) are homologous to the carbohydrate-binding domain of streptococcal glucosyltransferases (GTFs) that were recently identified as potent modulins. To test the hypothesis that ARU might exert a similar biological activity on endothelial cells, recombinant ARU (rARU), which was noncytotoxic to cell cultures, was analyzed using human umbilical vein endothelial cells. The rARU could bind directly to endothelial cells in a serum- and calcium-dependent manner and induce the production of interleukin-6 (IL-6), IL-8, and monocyte chemoattractant protein 1 in a dose-dependent manner. An oligosaccharide binding assay indicated that rARU, but not GTFC, binds preferentially to Lewis antigens and 3'HSO3-containing oligosaccharides. Binding of rARU to human endothelial or intestinal cells correlated directly with the expression of Lewis Y antigen. Bound rARU directly activated mitogen-activated protein kinases and the NF-kappaB signaling pathway in endothelial cells to release biologically active chemokines and adhesion molecules that promoted migration in a transwell assay and the adherence of polymorphonuclear and mononuclear cells to the endothelial cells. These results suggest that ARU may bind to multiple carbohydrate motifs to exert its biological activity on human endothelial cells.
Yeh
Chiou-Yueh
CY
Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan, Republic of China.
Lin
Chun-Nan
CN
Chang
Chuan-Fa
CF
Lin
Chun-Hung
CH
Lien
Huei-Ting
HT
Chen
Jen-Yang
JY
Chia
Jean-San
JS
D001427:Bacterial Toxins / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D054441:Cell Migration Assays, Leukocyte; D018925:Chemokines / Q000096:biosynthesis*; D002634:Chemotaxis, Leukocyte; D016360:Clostridioides difficile / Q000235:genetics / Q000276:immunology*; D042783:Endothelial Cells / Q000276:immunology*; D004768:Enterotoxins / Q000235:genetics / Q000276:immunology*; D004847:Epithelial Cells / Q000276:immunology*; D006801:Humans; D007962:Leukocytes / Q000276:immunology*; D007983:Lewis Blood Group Antigens / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D020449:Repetitive Sequences, Amino Acid / Q000276:immunology*
D001427:Bacterial Toxins; D018925:Chemokines; D004768:Enterotoxins; D007983:Lewis Blood Group Antigens; C094162:Lewis Y antigen; D016328:NF-kappa B; D011994:Recombinant Proteins; C041348:tcdA protein, Clostridium difficile; D020928:Mitogen-Activated Protein Kinases