Peptidoglycan as Nod1 ligand; Fragment structures in the environment, chemical synthesis, and their innate immunostimulation

This review focuses on the recent revealing of the immunostimulatory bacterial cell wall peptidoglycan (PGN) fragments as Nod1 ligands, especially a newly developed chemical synthesis of the partial structures, fragment structures in the environment and bacterial supernatant, and the immunostimulatory activities of the Nod1 ligands.