Delivery of Epitopes by the <i>Salmonella</i> Type III Secretion System for Vaccine Development

TLDR

Avirulent Salmonella typhimurium strains are being explored as antigen delivery vectors, yet their intracellular residence limits their ability to induce class I‑restricted immune responses. The authors employed the bacterium’s type III secretion system to transport viral epitopes directly into host‑cell cytosol. This strategy triggered class I‑restricted immunity that protected animals from lethal infection, indicating that S.

Abstract

Avirulent strains of Salmonella typhimurium are being considered as antigen delivery vectors. During its intracellular stage in the host, S. typhimurium resides within a membrane-bound compartment and is not an efficient inducer of class I–restricted immune responses. Viral epitopes were successfully delivered to the host-cell cytosol by using the type III protein secretion system of S. typhimurium . This resulted in class I–restricted immune responses that protected vaccinated animals against lethal infection. This approach may allow the efficient use of S. typhimurium as an antigen delivery system to control infections by pathogens that require this type of immune response for protection.