The innate immune system is the body’s first line of defense against invading bacterial pathogens. A critical component of this immune defense are the cytosolic NOD-like receptors (NLRs), which sense bacterial derived peptidoglycan fragments to elicit a downstream immune response. NLR’s of particular interest to human health are NOD2 and NLRP1, as mutations in both are associated with increased susceptibility to a host of autoimmune and inflammatory diseases, including Crohn’s disease. Though the leucine rich repeat (LRR) domain is commonly proposed as a site of molecular recognition for these receptors, the mechanisms by which these proteins sense and respond to bacterial signals remains poorly understood. Limited knowledge of this interaction makes the development of targeted therapeutics of inflammation very challenging. In order to gain insight into the mechanisms of NLR activation, we have developed biophysical tools to better understand how these receptors respond to signals that generate an immune response. Using surface plasmon resonance (SPR) to probe the promiscuity of these proteins for peptidoglycan fragments has given us insight for the first time into the orientation requirements of these ligands within NLR binding pockets, as well as revealed their unique low nanomolar carbohydrate binding affinity. The mechanisms of recognition of these proteins are also being extensively studied using photo crosslinking probes. We have developed of a library of photoactivatable crosslinker peptidoglycan derivatives, incorporating different photoactivatable groups at different positions around the carbohydrate. These probes have shown that both carbohydrate and peptide fragments of peptidoglycan can crosslink preferentially into the LRR domains of both NOD2 and NLRP1. These techniques are currently being used to identify the exact sites of molecular recognition within the NLR’s and to develop <i>in vivo</i> methods to track crosslinked proteins within cells. These tools have revealed new details about what types of ligands can be sensed by NOD2 and NLRP1 and have opened the door for development of probes to directly target uncontrolled inflammation.

Use of biophysical tools and peptidoglycan derived photo-crosslinking probes to elucidate molecular recognition mechanisms between carbohydrates and innate immune receptors

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.