Engineering Outer Membrane Vesicles for Multivalent Vaccine Delivery
Yehou Michel Davy Gnopo
Department of Chemical and Biomolecular Engineering, Cornell University, Ithaca NY 14853 USA
ymg7@cornell.edu
Abstract
Vaccines prime our immune system to fight potential pathogenic infections. Their effectiveness is highest when the right antigen is used in their formulation. Historically, vaccine formulations that rely on inactivated or killed forms of whole pathogens have been the most potent. However, with many safety concerns, subunit vaccines have become more popular. In most cases, the immune response elicited by the antigens in subunit vaccine formulations on their own is weak, thus requiring a boost given by chemical or biological agents known as adjuvants through a variety of mechanisms. The resulting immune protection in these cases may not be long-lasting, further requiring booster shots. Understandably, a solution to this vaccine efficacy problem that is currently being explored is the co-delivery of multiple antigens. The question is then should the delivery mirror the pathogen by using a delivery vehicle that contains multiple antigens, or is the immune response sufficient if the antigens are administered as a simple mixture? This presentation will discuss our work in answering this question through the engineering of a co-delivery platform based on promising vaccine delivery vehicles known as outer membrane vesicles (OMVs).
OMVs are spherical lipid bilayers, nanometers in size, that naturally bud from the outer membrane of bacteria. Due to their origin, they contain biomolecules that can aid in modulating the immune response, thus acting as adjuvants themselves. Previous work done by our group has shown that this vaccine engineering approach is successful in preventing a lethal influenza infection in rodents. To engineer the OMV platform to co-deliver multiple antigens, we use a process known as membrane fusion to create hybrid vesicles. Membrane fusion is a naturally occurring biological process that we induce under controlled conditions such as a combination of salt, pH, and temperature pertaining to the specific type of vesicle used in the fusion reaction. The hybrid vesicles we engineered can play a major role in rethinking the current approach to vaccine formulation.
Short Bio
Yehou Michel Davy Gnopo is an incoming Senior Scientist in the Vaccine Process Development and Commercialization (VPDC) group at Merck. He received his B.S. in Chemical and Biomolecular Engineering from Lafayette College and his Ph.D. from the Robert F. Smith School of Chemical and Biomolecular Engineering at Cornell University. He completed his dissertation in the laboratory of Dr. David Putnam combining colloidal chemistry and molecular biology to lead the development of outer membrane vesicles for multivalent vaccine delivery. He is a current Fellow of the Cornell’s Engineering PhD Commercialization Fellowship program and an Africa Fund Fellow of the Cornell Graduate School. He was also a Graduate Fellow of the Cornell’s Kavli Institute for Nanoscale Science and a Fleming scholar of the Cornell’s Robert F. Smith School of Chemical and Biomolecular Engineering.