title: NOD2/CARD15 genotype influences MDP-induced cytokine release and basal IL-12p40 levels in primary isolated peripheral blood monocytes.
abstract: BACKGROUND
  The functional link between mutations in NOD2 and Crohn's disease (CD) has not been entirely elucidated. The 1007fs mutation results in loss of NF-kappaB activation in response to muramyl dipeptide (MDP) but has also been linked to an increased IL-1beta processing and IL-12 release.
  
  
  METHODS
  We investigated the basal and MDP-triggered mRNA expression and protein release for TNF-alpha, IL-10, IL-1beta, and IL-12p40 in peripheral blood monocytes from 40 CD patients and 15 healthy individuals with different NOD2 genotypes.
  
  
  RESULTS
  Monocytes from individuals with 2 mutated NOD2 alleles (homozygous and compound-heterozygous individuals) displayed an impaired release of TNF-alpha and IL-10 but also of IL-1beta and IL-12p40 in response to MDP. In contrast to other NOD2 variants, the presence of at least 1 1007fs allele in double-mutated individuals completely abrogated NOD2 receptor function. Interestingly, monocytes from CD patients with 2 mutated NOD2 alleles displayed significantly higher basal levels of IL-12p40 in cell culture supernatants compared to wildtype CD patients and control individuals (P = 0.002 and P = 0.008, respectively). This was regardless of the IL23R genotype and was not mirrored by increased IL-12p40 plasma levels in these individuals.
  
  
  CONCLUSIONS
  The CD-associated NOD2 variants lead, in a dose- and mutation-dependent manner, to an impaired release of TNF-alpha, IL-10, IL-1beta, and IL-12p40 in response to MDP. The finding of increased basal levels for IL-12p40-related cytokines in monocytes with 2 mutated NOD2 alleles is likely to set a new link between NOD2 mutations and the inflammatory mechanisms underlying CD.
authors.affiliation: Department of Surgery, Innenstadt, University of Munich, Germany.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Beynon
authors.forename: Sebastian
authors.initials: S
authors.lastname: Cotofana
authors.forename: Stephan
authors.initials: S
authors.lastname: Brand
authors.forename: Peter
authors.initials: P
authors.lastname: Lohse
authors.forename: Anja
authors.initials: A
authors.lastname: Mair
authors.forename: Stefanie
authors.initials: S
authors.lastname: Wagner
authors.forename: Thomas
authors.initials: T
authors.lastname: Mussack
authors.forename: Thomas
authors.initials: T
authors.lastname: Ochsenkühn
authors.forename: Matthias
authors.initials: M
authors.lastname: Folwaczny
authors.forename: Christian
authors.initials: C
authors.lastname: Folwaczny
authors.forename: Jürgen
authors.initials: J
authors.lastname: Glas
authors.forename: Helga-Paula
authors.initials: HP
authors.lastname: Török
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000494:pharmacology; D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D016022:Case-Control Studies; D003424:Crohn Disease / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005838:Genotype; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D053762:Interleukin-12 Subunit p40 / Q000378:metabolism*; D053583:Interleukin-1beta / Q000378:metabolism; D008297:Male; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism*; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha
chemical_list: D000276:Adjuvants, Immunologic; D053762:Interleukin-12 Subunit p40; D053583:Interleukin-1beta; C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D000119:Acetylmuramyl-Alanyl-Isoglutamine