NOD-like receptors in the human upper airways: a potential role in nasal polyposis.
BACKGROUND
Nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) are newly discovered cytosolic receptors belonging to the pattern-recognition receptor family. They detect various pathogen-associated molecular patterns, triggering an immune response. The knowledge about these receptors, and their role in health and disease, is limited. The aim of the present study was to characterize the expression of NOD1, NOD2, and NALP3 in the human upper airways.


METHODS
Surgical samples were obtained from patients with tonsillar disease (n = 151), hypertrophic adenoids (n = 9), and nasal polyposis (n = 24). Nasal biopsies were obtained from healthy volunteers (n = 10). The expression of NOD1, NOD2, and NALP3 was analyzed using real-time PCR and immunohistochemistry.


RESULTS
Expression of NOD1, NOD2, and NALP3 mRNA and protein were seen in all tissue specimens. The NLR mRNA was found to be higher in nasal polyps than in normal nasal mucosa, and local steroid treatment reduced the NLR expression in polyps. In contrast, tonsillar infection with Streptococcus pyogenes or Haemophilus influenzae did not affect the NLR expression.


CONCLUSIONS
The present study demonstrates the presence of NLRs in several upper airway tissues and highlights a potential role of NLRs in chronic rhinosinusitis with polyps.
Division of ENT Diseases, Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
A
A
Månsson
J
J
Bogefors
A
A
Cervin
R
R
Uddman
L O
LO
Cardell
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002352:Carrier Proteins / Q000032:analysis / Q000235:genetics; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007113:Immunity, Innate; D008297:Male; D008875:Middle Aged; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; D009298:Nasal Polyps / Q000737:chemistry / Q000209:etiology*; D053472:Nod Signaling Adaptor Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D053474:Nod1 Signaling Adaptor Protein / Q000032:analysis / Q000235:genetics; D053473:Nod2 Signaling Adaptor Protein / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D012137:Respiratory System / Q000737:chemistry*; D014018:Tissue Distribution; D055815:Young Adult
D002352:Carrier Proteins; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C453881:NLRP3 protein, human; C119067:NOD1 protein, human; C429018:NOD2 protein, human; D053472:Nod Signaling Adaptor Proteins; D053474:Nod1 Signaling Adaptor Protein; D053473:Nod2 Signaling Adaptor Protein; D012333:RNA, Messenger