Expression of interleukin (IL)-12 (p40) and IL-12 (beta 2) receptors in allergic rhinitis and chronic sinusitis.
BACKGROUND
Interleukin (IL)-12 is a relatively new and structurally distinct TH1-associated cytokine produced by B cells and macrophages, which may play a suppressive role in the development of allergic sinonasal mucosal responses.


OBJECTIVE
We investigated the expression of IL-12 (inducible p40 subunit) and its receptor (IL-12R beta2 subunit) in tissue biopsies of naturally exposed patients with allergy-associated (ACS) and nonallergy-associated chronic sinusitis (NCS) and compared it with controls. We also examined IL-12 and IL-12R expression in biopsies from a ragweed allergen challenge model. In the allergen challenge model, the effect of pretreatment with topical corticosteroids on IL-12 and IL-12R expression was assessed.


METHODS
To detect IL-12 and IL-12R mRNA, we employed the technique of in situ hybridization using digoxigenin-labelled riboprobes.


RESULTS
In both ACS and NCS subjects there was decreased expression of IL-12 as compared with control (P < 0.05). IL-12R (beta2) expression was decreased in ACS subjects as compared with control (P < 0.05), however, there was no significant difference found between NCS subjects and control. In the allergen challenge subjects, there was a significant decrease in IL-12 expression following challenge (P < 0.05). This effect was abrogated by pretreatment of the subjects with topical corticosteroids. However, IL-12R (beta2) expression showed no change following allergen challenge while pretreatment with topical corticosteroids resulted in increased expression of the (beta2) receptor after allergen challenge (P < 0.05).


CONCLUSIONS
Our data suggest that IL-12 plays a role in the in vivo suppression of the allergic inflammatory response and that the control of this suppression may be exerted largely via the IL-12 (beta2) receptor.
Wright
E D
ED
Meakins-Christie Laboratories, Montreal, Quebec, Canada.
Christodoulopoulos
P
P
Frenkiel
S
S
Hamid
Q
Q
D000328:Adult; D000485:Allergens / Q000276:immunology; D052179:Antigens, Plant; D019819:Budesonide / Q000627:therapeutic use; D002908:Chronic Disease; D005260:Female; D006801:Humans; D018664:Interleukin-12 / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000737:chemistry / Q000276:immunology; D010256:Paranasal Sinuses / Q000737:chemistry / Q000276:immunology; D010940:Plant Proteins / Q000276:immunology; D011058:Pollen / Q000276:immunology; D020033:Protein Isoforms / Q000096:biosynthesis; D018123:Receptors, Interleukin / Q000096:biosynthesis*; D053707:Receptors, Interleukin-12; D012221:Rhinitis, Allergic, Perennial / Q000188:drug therapy / Q000276:immunology*; D012852:Sinusitis / Q000188:drug therapy / Q000276:immunology*
D000485:Allergens; C028564:Amb a III protein, Ambrosia artemisiifolia; D052179:Antigens, Plant; C508439:IL12RB2 protein, human; D010940:Plant Proteins; D020033:Protein Isoforms; D018123:Receptors, Interleukin; D053707:Receptors, Interleukin-12; D018664:Interleukin-12; D019819:Budesonide