Differential entry of Botulinum Neurotoxin A into neuronal and intestinal cells: an ultrastructural approach
Résumé
Recombinant C-terminus (Hc) of botulinum neurotoxin A (BoNT/A) was used to monitor toxin entry into NG108-15 neuronal cells and m-ICcl2 intestinal cells by both fluorescence and electronic microscopy. BoNT/A Hc entered neuronal cells via a clathrin pathway and intestinal cells mainly via non-clathrin vesicles. Upon incubation at 4°C, BoNT/A Hc gold particles were mainly distributed to neuronal cell periphery and to a lower extent to m-ICcl2 cells. After incubation at 37°C, BoNT/A Hc mostly transited in coated vesicles in NG108-15 cells and in uncoated vesicles of m-ICcl2 cells, which support the transcytotic passage of the toxin.