John Barrett, Ph.D.

Peptide vaccines have the advantage of providing only the necessary epitopes to induce an immunogenic response. Alone, however, they can be very weak immunogens. The group's solution is to deliver the epitope as part of a peptide amphiphile (PA) micelle system. This system creates a high local concentration of peptide, induces peptide secondary structure, and allows for modularity of micelle parts by inserting multiple amphiphiles or adjuvants (non-specific immuno-stimulants). Most of John's research will focus on developing a vaccine against Streptococcus pyogenes, which is the causative agent of Group A Streptococcal (GAS) infections including Necrotizing Fascitis. The PA and adjuvant mixed PA micelles have been shown to induce a high antibody titer. However, the method of immunogenicity has yet to be worked out. Characterizing the immune response will finally develop the full story for this vaccine. Additionally, John will be investigating alternate GAS vaccine candidates that will target and disrupt streptococcal quorum sensing (bacterial cell-cell communication) pathways in collaboration with the Federle Lab at the University of Illinois at Chicago. He proposes that these vaccines will help develop antibodies that interfere with pheromone production and detection.