Figure 3.
Models for the intestinal absorption of the BoNT complexes. L-PTC, M-PTC or BoNT could be adsorbed by transcytosis that is mediated by carbohydrates and/or unknown protein receptors on the cell surface. When the L-PTC gains access to E-cadherin, the HA complex could disrupt the epithelial barrier, leading to efficient absorption of BoNTs and PTCs through the paracellular route. After crossing the epithelial barrier, BoNT dissociates from the complex and enters into the systemic circulation.