Interaction of Botulinum Toxin with the Epithelial Barrier
Figure 3
Model for penetration of BoNT complexes through the intestinal epithelial barrier. Step : HA of the BoNT complex mediates binding and transcytosis of a small amount of luminally located BoNT complexes across the epithelium without disrupting the epithelial barrier (Arrows in yellow, “route i”) [65]. H chain of BoNT also mediates binding and transcytosis of BoNT (Arrows in green, “route ii”) [61–66]. Step : HA which has translocated on the basolateral surface disrupts the epithelial barrier. Types A and B HA proteins disrupt the paracellular barrier of without causing cytotoxic effects in the epithelial cells of their susceptible hosts [65, 77]. Type C HA proteins possibly evoke cytotoxic-barrier disrupting activity in the epithelial cells of susceptible animals [77]. Step : A large amount of the BoNT complexes and BoNT accumulates in the serosal side by passing from the damaged epithelial barrier (Arrows in light green, “route iii”) [65].
