Overexpression of the anaphylatoxin receptors, complement anaphylatoxin 3a receptor and complement anaphylatoxin 5a receptor, in the nasal mucosa of patients with mild and severe persistent allergic rhinitis.
BACKGROUND
Although the complement anaphylatoxin peptides, complement anaphylatoxin 3a (C3a) and complement anaphylatoxin 5a (C5a), are implicated in the inflammatory process in allergic rhinitis, a direct interaction between allergic mucosa and complement receptors has not been demonstrated.


OBJECTIVE
We investigated the expressional levels and distributional patterns of the C3a receptor (C3aR) and C5a receptor (C5aR) in normal, mild, and severe persistent allergic nasal mucosa.


METHODS
Immunohistochemistry and Western blotting using C3aR and C5aR antibodies were applied to normal nasal, mild, and severe persistent allergic nasal mucosa.


RESULTS
Complement anaphylatoxin 5a receptor was detected in the inflammatory cells of normal and allergic nasal mucosa, and its expression level was significantly higher in allergic nasal mucosa than normal nasal mucosa. C3aR in normal and allergic nasal mucosa was commonly expressed in nonmyeloid cells such as epithelial cells, submucosal glands, and nerve fibers. In addition, C3aR was expressed in the endothelium of cavernous sinuses and the surrounding perivascular muscle layer in severe persistent allergic nasal mucosa, but not in normal and mild allergic nasal mucosa. Western blotting demonstrated that the expression level of C3aR was significantly increased in severe persistent allergic nasal mucosa compared with normal and mild nasal mucosa.


CONCLUSIONS
On the basis of the location of C3aR and C5aR, C5aR may play a role in activation of inflammatory cells, whereas C3aR may mediate mucus secretion and mucosal swelling in allergic nasal mucosa, especially severe persistent allergic nasal mucosa.
Department of Otorhinolaryngology-Head and Neck Surgery, National Medical Center, Seoul, Korea.
Sung Whan
SW
Jun
Tae Hoon
TH
Kim
Heung Man
HM
Lee
Seung Hoon
SH
Lee
Woo Joo
WJ
Kim
Se Jin
SJ
Park
Yang Soo
YS
Kim
Sang Hag
SH
Lee
D000328:Adult; D015153:Blotting, Western; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009297:Nasal Mucosa / Q000166:cytology / Q000276:immunology*; D044087:Receptor, Anaphylatoxin C5a / Q000276:immunology / Q000378:metabolism*; D011951:Receptors, Complement / Q000276:immunology / Q000378:metabolism*; D012221:Rhinitis, Allergic, Perennial / Q000276:immunology* / Q000378:metabolism
D044087:Receptor, Anaphylatoxin C5a; D011951:Receptors, Complement; C085567:complement C3a receptor