Recognition of peptidoglycan from the microbiota by Nod1 enhances systemic innate immunity

Jeffrey Weiser and his colleagues provide a mechanism for a beneficial effect from commensal bacteria that colonize the gut. They show that peptidoglycan from gut microbiota traverses the gut mucosa and boosts the systemic innate immune response by priming neutrophils in the bone marrow. Such priming requires the recognition of peptidoglycan by the intracellular receptor Nod-1 ( pages 160–161 ).