Nod1, Nod2 and Nalp3 receptors, new potential targets in treatment of allergic rhinitis?
BACKGROUND
Recently, a new set of pattern-recognition receptors, the nucleotide-binding oligomerization domain (Nod)-like receptors (NLRs), have emerged. Their activation, either by allergens or microbes, triggers an inflammatory response. The knowledge about NLRs in human airways is limited.


OBJECTIVE
To investigate presence of NLRs in the human nose of healthy individuals and patients with intermittent allergic rhinitis outside and during pollen season.


METHODS
The expression of Nod1, Nod2, and Nalp3 in nasal biopsies was determined with real-time RT-PCR and immunohistochemistry. Cultured primary human nasal epithelial cells (HNECs) were analyzed using real-time RT-PCR and flow cytometry to further verify the presence of NLRs in the epithelium.


RESULTS
Immunohistochemical analysis revealed presence of Nod1, Nod2, and Nalp3 in the nasal epithelium. This was corroborated in cultured HNECs. Patients suffering from symptomatic allergic rhinitis exhibited lower Nod1 and Nalp3 mRNA levels than both controls and patients during pollen season. Nod2 expression was found in all specimens tested, but no differences were seen between the three groups.


CONCLUSIONS
Nod1, Nod2, and Nalp3 receptors were found to be present in the human nose. The expression of Nod1 and Nalp3 were down-regulated during pollen season among patients with allergic rhinitis. This opens up for new insights and novel therapeutic strategies in inflammatory airway disease.
Bogefors
J
J
Department of Otorhinolaryngology, Malmö University Hospital, Lund University, Malmö, Sweden.
Rydberg
C
C
Uddman
R
R
Fransson
M
M
Månsson
A
A
Benson
M
M
Adner
M
M
Cardell
Lars Olaf
LO
D002352:Carrier Proteins / Q000032:analysis* / Q000235:genetics; D016022:Case-Control Studies; D002478:Cells, Cultured; D015536:Down-Regulation; D016503:Drug Delivery Systems; D004847:Epithelial Cells / Q000737:chemistry; D006801:Humans; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; D053474:Nod1 Signaling Adaptor Protein / Q000032:analysis* / Q000235:genetics; D053473:Nod2 Signaling Adaptor Protein / Q000032:analysis* / Q000235:genetics; D009666:Nose / Q000473:pathology; D051192:Receptors, Pattern Recognition; D012220:Rhinitis / Q000188:drug therapy / Q000378:metabolism*; D012221:Rhinitis, Allergic, Perennial; D006255:Rhinitis, Allergic, Seasonal; D012621:Seasons
D002352:Carrier Proteins; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C453881:NLRP3 protein, human; D053474:Nod1 Signaling Adaptor Protein; D053473:Nod2 Signaling Adaptor Protein; D051192:Receptors, Pattern Recognition