Poster Presentation 20th Lancefield International Symposium on Streptococci and Streptococcal Diseases 2017

PilVax: a novel peptide carrier for the development of vaccines against tuberculosis (#164)

Samuel D Blanchett 1 , Thomas Proft 1 , Jacelyn Loh 1 , Catherine Tsai 1
  1. The University of Auckland, Auckland, AUCKLAND, New Zealand

PilVax is a peptide delivery strategy for the generation of highly specific mucosal immune responses. The food-grade bacterium Lactococcus lactis is used to express selected peptides engineered within the group A streptococcal pilus, thereby allowing for peptide amplification, stabilization, and enhanced immunogenicity. A pilot study showed that mice immunised with PilVax expressing the model peptide Ova324-337 presented strong IgG and IgA responses to ovalbumin. The present study aims to demonstrate the suitability of PilVax for the generation of novel peptide vaccines against tuberculosis. Selected peptides (B cell and T cell epitopes), derived from tuberculosis vaccine targets, were genetically engineered into loop regions of the pilus backbone subunit and expressed in L. lactis. Western blots confirmed pilus formation on L. lactis. Antibody responses from mice immunised intranasally with recombinant L. lactis were strong against the pilus backbone, but weak against the target peptide. However, the poor antibody responses to the two peptides tested thus far were expected, due to being primarily T cell epitopes. We are currently also testing PilVax expressing selected B cell epitopes, and analysing the T cell responses of all constructs.