Development of a synthetic receptor protein for sensing inflammatory mediators interferon- and tumor necrosis factor-

Intestinal inflammation has been implicated in a number of diseases, including diabetes, Crohn's disease, and irritable bowel syndrome. Important components of inflammation are interferon- (IFN-) and tumor necrosis factor- (TNF-), which are elevated both on the luminal and submucosal sides of the intestinal epithelial barrier in several diseases. Here, we developed a novel Escherichia coli based detection system for IFN- and TNF- comprised of a chimeric protein and a simple signal transduction construct, which could be deployed on the luminal side of the intestine. OmpA of E. coli was engineered to detect IFN- or TNF- through the replacement of extracellular loops with peptide fragments from OprF of P. aeruginosa. OmpA/OprF chimeras were developed, capable of binding IFN- or TNF-. The specific peptide fragments that bind IFN- were identified. IFN- or TNF- binding the OmpA/OprF chimera induced the pspA promoter, driving -galactosidase production. The OmpA/OprF chimera had a detection limit of 300pM for IFN- and 150pM for TNF-. This work will further the development of bacteria based therapeutics for the treatment of inflammatory diseases of the gut. Biotechnol. Bioeng. 2016;113: 492-500. (c) 2015 Wiley Periodicals, Inc.