Research Article

Retargeting Clostridium difficile Toxin B to Neuronal Cells as a Potential Vehicle for Cytosolic Delivery of Therapeutic Biomolecules to Treat Botulism

Figure 5

A TcdB chimera with the BoNT/A receptor-binding domain has increased specificity for neuronal cells. (a) Toxin potency of AGT-TcdB and AGT-TcdB-BoNT/A-Hc on two neuronal cell lines and Vero cells. Potency was assessed by serial dilutions of purified recombinant AGT-TcdB-BoNT/A-Hc (▲) and AGT-TcdB (∘). The potency was determined on Neuro2A and M17 neuroblastoma cells and Vero cells. Fivefold serial dilutions of the proteins were added to medium, and cells were monitored for toxicity by assessing the % cell rounding after 24 hr. Data shown are representative of 4 independent experiments. (b) Microscopic images of Neuro2A cells exposed to AGT-TcdB or AGT-TcdB-BoNT/A-Hc. Representative images are shown of Neuro2A cells exposed for 24 hr to 0.16 ng/mL or 4 ng/mL of either AGT-TcdB-BoNT/A-Hc or AGT-TcdB, respectively.
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