Antimicrobial Peptide Production using the Type 3 Secretion System in Salmonella

Antimicrobial peptides (AMPs) are oligopeptides of various lengths, and they are an important component of the innate immune system. AMPs are currently being evaluated as a novel family of antibiotic, due largely to growing antibiotic resistance. AMPs could be used to make self-decontaminating surfaces or in antibiotic creams. AMPs are currently made via chemical synthesis. Most microbial hosts cannot produce these peptides, because AMPs are lethal to microbes. The Type 3 Secretion System in Salmonella is a promising platform to secrete toxic peptides or proteins. It is believed that secreted peptides and proteins secreted are bound or unfolded until after secretion, limiting the substrate's toxicity. Once secreted, diffusion into the extracellular space further protects the host from toxicity. We have used the T3SS to secrete an antimicrobial peptide, and this secretion does not seem to affect overall growth rate. We are currently working to secrete other antimicrobial peptides. This work could improve the way Antimicrobial Peptides are made, lowering the overall cost of synthesis.