BACKGROUND: The allergen-induced late nasal response is associated with a high local expression of interleukin (IL) -4, a TH2-type cytokine implicated in immunoglobulin (Ig) E production, tissue eosinophilia and other events considered to be relevant to allergic inflammation. Interaction of IL-4 with its receptor activates at least two distinct signalling pathways that culminate in the transcription of specific target genes. One pathway involves the activation of a transcription factor termed signal transducer and activator of transcription factor 6 (STAT6). OBJECTIVE: To investigate the expression of STAT6 in the allergen-induced late nasal response and to examine the effect of local steroid treatment on STAT6 expression. METHODS: Inferior turbinate biopsies were obtained from subjects with allergic rhinitis out of the allergen season. Subjects were then randomized into topical steroid- (n = 6) and placebo-treated (n = 6) groups in a double-blind fashion. After a 6-week treatment period, a second nasal biopsy was performed 24 h after local challenge with allergen. STAT6 immunoreactivity was examined in biopsy specimens by immunocytochemistry using a specific monoclonal antibody. Numbers of inflammatory cells (CD3+ T cells and MBP+ eosinophils) and IL-4 mRNA+ cells were investigated by immunocytochemistry and in situ hybridization, respectively. RESULTS:STAT6 immunoreactivity was detected in all biopsies studied and localized predominantly to inflammatory tissue of the nasal mucosa. After allergen challenge, expression of STAT6 was markedly increased in placebo-treated patients (P < 0.01). By confocal microscopy, STAT6 was localized to the cytoplasm and the nucleus of positively-staining cells. The allergen-induced increase in STAT6 immunoreactive cells was not observed in the steroid-treated patients. The change in STAT6 immunoreactivity after allergen challenge correlated significantly with the change in numbers IL-4mRNA+ cells (r = 0.74, P = 0.006) and CD3+ T cells (r = 0.76, P = 0. 004), but not MBP+ eosinophils. CONCLUSION: This study provides the first evidence of increased STAT6 expression in vivo in human allergic inflammation. The results support a role for STAT6 and IL-4 in the pathogenesis of late nasal response and show that decreases in STAT6 expression parallel the reduction in IL-4 expression that occurs with topical steroid treatment.
RCT Entities:
BACKGROUND: The allergen-induced late nasal response is associated with a high local expression of interleukin (IL) -4, a TH2-type cytokine implicated in immunoglobulin (Ig) E production, tissue eosinophilia and other events considered to be relevant to allergic inflammation. Interaction of IL-4 with its receptor activates at least two distinct signalling pathways that culminate in the transcription of specific target genes. One pathway involves the activation of a transcription factor termed signal transducer and activator of transcription factor 6 (STAT6). OBJECTIVE: To investigate the expression of STAT6 in the allergen-induced late nasal response and to examine the effect of local steroid treatment on STAT6 expression. METHODS: Inferior turbinate biopsies were obtained from subjects with allergic rhinitis out of the allergen season. Subjects were then randomized into topical steroid- (n = 6) and placebo-treated (n = 6) groups in a double-blind fashion. After a 6-week treatment period, a second nasal biopsy was performed 24 h after local challenge with allergen. STAT6 immunoreactivity was examined in biopsy specimens by immunocytochemistry using a specific monoclonal antibody. Numbers of inflammatory cells (CD3+ T cells and MBP+ eosinophils) and IL-4 mRNA+ cells were investigated by immunocytochemistry and in situ hybridization, respectively. RESULTS:STAT6 immunoreactivity was detected in all biopsies studied and localized predominantly to inflammatory tissue of the nasal mucosa. After allergen challenge, expression of STAT6 was markedly increased in placebo-treated patients (P < 0.01). By confocal microscopy, STAT6 was localized to the cytoplasm and the nucleus of positively-staining cells. The allergen-induced increase in STAT6 immunoreactive cells was not observed in the steroid-treated patients. The change in STAT6 immunoreactivity after allergen challenge correlated significantly with the change in numbers IL-4 mRNA+ cells (r = 0.74, P = 0.006) and CD3+ T cells (r = 0.76, P = 0. 004), but not MBP+ eosinophils. CONCLUSION: This study provides the first evidence of increased STAT6 expression in vivo in humanallergic inflammation. The results support a role for STAT6 and IL-4 in the pathogenesis of late nasal response and show that decreases in STAT6 expression parallel the reduction in IL-4 expression that occurs with topical steroid treatment.
Authors: Steve N Georas; Rosalind J Wright; Anastasia Ivanova; Elliot Israel; Lisa M LaVange; Praveen Akuthota; Tara F Carr; Loren C Denlinger; Merritt L Fajt; Rajesh Kumar; Wanda K O'Neal; Wanda Phipatanakul; Stanley J Szefler; Mark A Aronica; Leonard B Bacharier; Allison J Burbank; Mario Castro; Laura Crotty Alexander; Julie Bamdad; Juan Carlos Cardet; Suzy A A Comhair; Ronina A Covar; Emily A DiMango; Kim Erwin; Serpil C Erzurum; John V Fahy; Jonathan M Gaffin; Benjamin Gaston; Lynn B Gerald; Eric A Hoffman; Fernando Holguin; Daniel J Jackson; John James; Nizar N Jarjour; Nicholas J Kenyon; Sumita Khatri; John P Kirwan; Monica Kraft; Jerry A Krishnan; Andrew H Liu; Mark C Liu; M Alison Marquis; Fernando Martinez; Jacob Mey; Wendy C Moore; James N Moy; Victor E Ortega; David B Peden; Emily Pennington; Michael C Peters; Kristie Ross; Maria Sanchez; Lewis J Smith; Ronald L Sorkness; Michael E Wechsler; Sally E Wenzel; Steven R White; Joe Zein; Amir A Zeki; Patricia Noel Journal: J Allergy Clin Immunol Date: 2021-11-29 Impact factor: 14.290
Authors: Gaetano Caramori; David Groneberg; Kazuhiro Ito; Paolo Casolari; Ian M Adcock; Alberto Papi Journal: J Occup Med Toxicol Date: 2008-02-27 Impact factor: 2.646