NODs in defence: from vulnerable antimicrobial peptides to chronic inflammation.
Defensins and cathelicidins are prevalent and essential gastrointestinal cationic antimicrobial peptides (CAPs). However, these defensive peptides are not infallible because certain enteropathogens can overcome their protective function. Furthermore, impaired defensin synthesis has been linked to the occurrence of Crohn's disease (CD), a chronic inflammatory bowel disease. Recently, defective bacterial sensing through NOD1 and NOD2 has been related to reduced defensin production, CD predisposition and susceptibility to enteric infection. Hence, we propose that microbial sensors at the gut interface monitor the levels of these effector peptides, which might function as "danger" signals to confer tolerance and alert immunocytes. Further work is required to clarify how gastrointestinal CAPs are regulated and to assess their role in maintaining epithelial homeostasis and triggering adaptive immunity.
Peyrin-Biroulet
Laurent
L
INSERM U795, University of Lille 2, Huriez Hospital, Digestive Tract Diseases and Nutrition Department, F-59037 Lille, France.
Vignal
Cécile
C
Dessein
Rodrigue
R
Simonet
Michel
M
Desreumaux
Pierre
P
Chamaillard
Mathias
M
D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D003424:Crohn Disease / Q000276:immunology; D041981:Gastrointestinal Tract / Q000737:chemistry / Q000276:immunology; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000276:immunology / Q000503:physiopathology*; D008969:Molecular Sequence Data; D053472:Nod Signaling Adaptor Proteins / Q000502:physiology*; D015398:Signal Transduction; D051193:Toll-Like Receptors / Q000276:immunology
D023181:Antimicrobial Cationic Peptides; D053472:Nod Signaling Adaptor Proteins; D051193:Toll-Like Receptors