Tailored cyclodextrin pore blocker protects mammalian cells from clostridium difficile binary toxin CDT

Area of Science:

• Microbiology
• Toxicology
• Biochemistry

Background:

• Clostridium difficile strains can produce a binary toxin (CDT) that contributes to hypervirulence.
• CDT consists of enzyme (CDTa) and translocation (CDTb) components, which enter host cells via endosomes.
• CDTb facilitates CDTa delivery into the cytosol by forming a pore in endosomal membranes.

Purpose of the Study:

• To investigate the potential of a cationic β-cyclodextrin derivative as an inhibitor of CDT activity.
• To determine if the β-cyclodextrin derivative affects toxin binding, enzymatic activity, or translocation.

Main Methods:

• Utilized a cationic β-cyclodextrin derivative, per-6-S-(3-aminomethyl)benzylthio-β-cyclodextrin.
• Assessed the compound's effect on CDT intoxication, actin ADP-ribosylation, toxin binding, and pH-dependent translocation in mammalian cells.

Main Results:

• The cationic β-cyclodextrin derivative protected cells from CDT intoxication.
• The compound did not inhibit CDTa's ADP-ribosylation of actin or toxin binding to cells.
• It specifically inhibited the pH-dependent translocation of CDTa into the cytosol.

Conclusions:

• Cationic β-cyclodextrins can effectively block CDT translocation into host cells.
• This compound represents a promising lead for developing novel pharmacological strategies against CDT-producing C. difficile.