CTB binding to primary human intestinal cells can be blocked by interference with fucosylated structures.

(A) Bar graph showing relative absorbance values from an ELISA with immobilized anti-Le^X, and detection with CTB-HRP. Samples as indicated from lysates of isolated human cells (2 μg protein/ml). Each dot represents a human donor (n = 5–8). (B) CD66 or (C) CD66 and Le^X expression by jejunal epithelial cells that were isolated using EDTA medium (villi) or enzymatic degradation after EDTA treatment (non-villi or crypt). Histograms from flow cytometry analyses of CTB-, G33D- and OVA-binding to the differentially enriched epithelial cells. (B) EpCAM⁺ cells and (C) EpCAM⁺Le^X+ cells. (D-G) Bar graph showing percent of gMFI of CTB binding to jejunal epithelial cells by pretreatment of the cells with (D) lectins, (E) sugars, (F) oligosaccharides and (G) HSA-linked oligosaccharides. Graphs show the percent of gMFI of CTB binding to the cells where 100% represents CTB staining with no blocking oligosaccharide. Each dot represents a donor in (D) n = 4–12, (E) n = 6–8, (F) n = 6–12, (G) n = 6–7. Significance was calculated using a one-way-ANOVA with Tukey correction compared to CTB without block if not indicated otherwise with bars (**** = p<0,0001, *** = p<0,005, ** = p<0,01 and * = p<0,05).