Reduced T-bet in addition to enhanced STAT6 and GATA3 expressing T cells contribute to human allergen-induced late responses.

BACKGROUND: T-bet and GATA-3 are transcriptional factors involved in Th1 and Th2 cell differentiation, although their concomitant roles at protein levels in target organs during human allergic disease have not been assessed. OBJECTIVES: We investigated the expression of T-bet and GATA-3 in nasal and cutaneous models of Th2 (grass-pollen allergen) and a cutaneous model of Th1 (PPD) responses in man. METHODS: Nasal biopsies were obtained at 8 h and skin biopsies at 8 and 48 h after allergen and PPD challenges, respectively, from 10 allergic rhinitics and 6 non-atopic controls. T cells were assessed using immunofluorescence microscopy. RESULTS: There were increases in CD3(+)STAT6(+)cells (P = 0.01 for nose and skin) and CD3(+)GATA3(+)cells (P = 0.03 for skin) in response to allergen compared with diluent in allergics. When compared with non-atopics after allergen challenge the difference between the two groups was also significant for CD3(+)STAT6(+) (P = 0.001 and 0.03) and for CD3(+)GATA3(+)cells (P = 0.04 and 0.001) for nose and skin respectively. Following PPD challenge CD3(+)STAT4(+)cells and CD3(+)T-bet(+)cells increased in both groups compared with diluent (P = 0.02 and 0.03 for both TFs), whereas only CD3(+)T-bet(+) cells were significantly greater in non-atopics compared with allergics (P = 0.04). The ratio of GATA3(+):T-bet(+) T cells in allergen-induced responses was significantly greater in the allergics (P = 0.008 and 0.01 nose and skin respectively), whereas the ratio of T-bet:GATA3(+)T cells was significantly higher in the non-atopics during PPD-induced responses (P = 0.003). CONCLUSIONS AND CLINICAL RELEVANCE: Dysregulation of Th1 transcription may contribute to heightened expression of STAT6 and GATA3 leading to exaggerated Th2-driven manifestations of allergic disease.

Increased nitric oxide production in nasal epithelial cells from allergic patients--RT-PCR analysis and direct imaging by a fluorescence indicator: DAF-2 DA.

BACKGROUND: Nitric oxide (NO) is believed to participate in the regulation of airway clearance and non-specific cellular immunity. Recent studies have suggested that airway epithelial cells of allergic and non-allergic individuals may differ in their ability to produce this molecule. OBJECTIVE: The aim of this study was to detect the difference in NO production in human nasal epithelial cells between normal subjects and patients with perennial allergic rhinitis (AR), and to assess the relationship between the expression of nitric oxide synthase (NOS) isoforms and the severity of the disease. METHODS: Nasal epithelial cells were obtained from the inferior turbinate. The expression of mRNAs encoding constitutive endothelial NOS (eNOS) and inducible NOS (iNOS) was studied by reverse transcription-polymerase chain reaction (RT-PCR). Direct NO production in living cells was visualized and quantified by a fluorescent indicator, DAF-2 DA. RESULTS: RT-PCR analysis demonstrated that AR patients with a RAST score of 5 or 6 showed significant increases in the levels of iNOS mRNA and slight reductions in those of eNOS mRNA. Patients with a RAST score of 2-4 also revealed the same tendency however, the difference was not significant. DAF-2 DA imaging demonstrated that epithelial cells, especially the ciliated cells, produced a larger amount of NO than non-epithelial inflammatory cells. Preincubation with L-NAME resulted in an approximate 40% decrease in both groups. CONCLUSION: These results directly indicate that nasal epithelial cells of AR patients overall produce higher levels of NO through the concomitant expression of different NOS isoforms. Continuous NO production by the epithelial cells in normal subjects further support the hypothesis that NO derived from epithelium may play dual roles in the regulation of nasal airway clearance and in the host defense. In addition, the use of DAF-2 DA provides a reliable method to visualize and quantify the direct NO production of living cells.

Analysis of local cytokine gene expression in patients with allergic rhinitis treated with CO2 laser surgery.

OBJECTIVES/HYPOTHESIS: Laser surgery of the inferior turbinates has become a popular surgical treatment for patients with allergic rhinitis, particularly for those who have persistent nasal obstruction and do not respond well to pharmacological therapy. The aim of this study was to investigate the effects of the laser surgery on local cytokine gene expression at the mucosal surface in relation to the improvement of nasal symptoms. STUDY DESIGN: A prospective analysis of 25 patients with allergic rhinitis caused by the house dust mite who underwent laser surgery twice with a 1-month interval on an outpatient basis. Fifteen healthy volunteers served as normal control subjects. METHODS: Improvement of the nasal symptoms was evaluated on a graded scale. Nasal mucosal cells were obtained by brushing from the inferior turbinate at each visit. The expression of messenger RNA (mRNA) encoding granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-6, IL-8, RANTES (regulated on activation, normal T-cell expressed and secreted), and eotaxin was semiquantitatively analyzed by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Two months after treatment, the nasal symptom scores significantly decreased from baseline. The decrease was most apparent in nasal obstruction. RT-PCR analysis revealed that a significant decrease in IL-8 and RANTES expression (P < .001 and P = .012, respectively) was observed after successive laser treatment, and the reduction in these cytokines was significantly correlated. On the other hand, mRNA expression of GM-CSF, IL-6, and eotaxin remained unchanged. CONCLUSIONS: This study provided evidence that the expression of local inflammatory cytokines can be attenuated in part by CO2 laser treatment, which may be closely related to the clinical effectiveness of this procedure.