Peptidoglycan fragments from the bacterial cell wall activate innate immune signaling pathways and limits infections in animals. Indeed, recent studies from the Hang and Mucida laboratories have shown that E. faecium secreted peptidoglycan hydrolase (SagA) generates smaller peptidoglycan fragments, muropeptides, which can enhance host epithelial barrier integrity and enteric pathogen tolerance. However, the direct biochemical interactions of muropeptides with their proposed pattern recognition receptors have been challenging to characterize. Here, I report the chemical synthesis of photoaffinity probes for the analysis of muropeptide-pattern recognition receptor interactions in cells. These studies reveal direct biochemical interactions of muropeptide with pattern recognition receptors and other potential cofactors in mammalian cells. Further characterization of muropeptide-pattern recognition receptor and cofactor complexes will be important for elucidating fundamental mechanisms of innate immunity and inflammation-associated diseases and cancer.

Citation Format: Yen-Chih Wang. Chemical probes for exploring muropeptide-pattern recognition receptor interactions in cells [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B195.