Engineering therapeutic AvrA nanoparticles with enhanced uptake and intracellular delivery with applications in inflammatory bowel disease

Abstract

The work presented in this thesis focuses on reengineering naturally-derived, evolutionarily optimized molecules as drug delivery vehicles and therapeutics. We have identified AvrA, used by Salmonella, as an effector enzyme with therapeutic potential due to its ability to modulate key intracellular signaling pathways in eukaryotic cells and confer anti-inflammatory and anti-apoptotic effects. Chronic inflammation in autoimmune diseases, such as inflammatory bowel disease, is a prime target that could benefit from treatment with AvrA. Modulating intracellular components with the use of enzymes presents a new strategy to combat inflammatory bowel disease. Salmonella possesses a type three needle-like secretion system used to deliver AvrA which can penetrate the cell membrane, giving direct access to the cytosol. Utilizing AvrA absent of Salmonella requires an alternative delivery system. To address this challenge, we engineered a protein nanoparticle encapsulating AvrA capable of intracellular delivery. AvrA nanoparticles were characterized and evaluated for their potential to treat inflammatory bowel disease and a pH responsive oral delivery vehicle made from naturally derived polysaccharides, alginate and chitosan, was used to encapsulate AvrA nanoparticles to increases it clinical potential. We also studied the role of carrier proteins in influencing protein nanoparticle properties. These properties can influence the protein corona that around them when administrated in vivo and guide cellular interactions to maximize cytosolic delivery.