Fig. 2: Cell surface fucosylation mediates the binding/entry of TcsH.
From: Paeniclostridium sordellii hemorrhagic toxin targets TMPRSS2 to induce colonic epithelial lesions
a The sensitivities of MCF-7 TMPRSS2‒/‒, GMDS‒/‒, FUT4‒/‒, and SLC35C1‒/‒ cell lines to TcsH were measured using the cytopathic cell-rounding assay. Error bars represent mean ± s.d., n = 6. b Schematic view of biosynthesis of fucosylated glycans, genes identified from the screens were highlighted. c Flow cytometry profiles of fluorescein isothiocyanate (FITC)-conjugated LTL (left) or AAL (right) binding to MCF-7 WT and KO cells. d The absence of TMPRSS2 expression in the MCF-7 TMPRSS2‒/‒ cells was validated by Western blot analysis. The MCF-7 GMDS‒/‒, FUT4‒/‒, and SLC35C1‒/‒ cells have similar TMPRSS2 expression levels compared to the WT cells. The experiments have been repeated independently twice with similar results. e Confocal fluorescence images show Rhodamine-labeled TcsH (green) or GFP-TcsH1832–2618 (green) bindings to the MCF-7 WT, GMDS‒/‒, FUT4‒/‒, SLC35C1‒/‒, and TMPRSS2‒/‒ cells, respectively. Cell nuclei were stained by Hoechst (blue). The scale bar represents 50 μm. f Co-incubation of the AAL (8 μg/mL) with TcsH (10 pM, 3.5 h) protected MCF-7 cells from intoxication and prevented cell rounding. g Confocal fluorescence images show binding of different GFP-fused TcsH CROPs fragments to the MCF-7 cells. Cell nuclei were stained by Hoechst (blue). The scale bar represents 50 μm.
