Analysis of Potential Fusion Proteins for Outer Membrane Vesicle-Based Lyme Disease Vaccine

Lyme disease, a vector-borne disease commonly spread to humans via tick bite, has been a prevalent and growing public health concern not only in the New York area but across the United States. Primarily caused by the bacteria Borrelia Burgdorferi (Bb), this disease is often difficult to diagnose correctly and if left to progress can cause severe chronic symptoms. The development of a vaccine for Lyme disease would be an ideal solution to this concern as it will stop the disease at its root. Our lab has been focusing on utilizing outer membrane vesicles (OMVs) as a platform for a Lyme disease vaccine. OMVs are nanoparticles produced by gram-negative bacteria that can be engineered to express foreign proteins on their surface. While they resemble bacteria, they should not pose a genuine threat to the body as they are not living and as such non-infectious, making them a promising delivery mechanism for vaccination. Our research evaluated the expression of different fusion proteins on the outer surface of OMVs using antigenic (immune reactive) proteins from Bb and Cytolysin A (ClyA) as a fusion partner. The proteins tested from Bb were Outer surface protein A (OspA) and Decorin-binding protein A (DbpA), as well as immunogenic epitopes (a small part of a protein that is recognized by the immune system). OMVs were produced and characterized using many techniques, primarily western blot analysis, dynamic light scattering, and protease accessibility assay. Studies suggest that all tested fusion proteins are effectively produced on the outer surface of the OMVs consistently. Further research will focus on ascertaining the protective immunogenic effect of these particles using an in vivo animal model.