In previous studies we demonstrated that the staphylococcal α-toxin inhibits adhesion and invasion of S. aureus by epithelial cells through binding to α5β1 integrin, a receptor of fibronectin. Moreover, we revealed that a H35A mutation abolishes the cytotoxicity of α-toxin completely. These findings led us to hypothesize that the H35A mutated α-toxin may be explored as a potential inhibitor for bacterial adhesion and invasion of epithelial cells. In this study, we examined the impact of the H35A α-toxin on staphylococcal capacity of adhering to and invading into epithelial cells and found that the addition of H35A α-toxin in the culture medium dramatically inhibited S. aureus' ability to adhere to and internalize into epithelial cells. Importantly, we demonstrated that both the staphylococcal α-toxin and H35A mutated α-toxin are capable of retarding the adhesion and invasion of epithelial cells by Streptococcus pyogenes. These findings suggest that the H35A toxoid has the potential to be utilized as an inhibitor of S. aureus and S. pyogenes ability to adhere to and invade epithelial cells.
Bibliographical noteFunding Information:
This work was partially supported by grant AI065740 and AI057451 from the National Institute of Allergy and Infectious Disease, and partially by the MAES competitive grants. We thank Mr. Jeffrey Hall for technical support and critical reading of the manuscript.
- Adhesion and invasion
- Group A streptococci
- H35A toxoid
- S. aureus