Search

Background: Nasal epithelial cells are the first site of encounter of the influenza virus, and their innate immune response might define subsequent inflammatory direction. Aims/objectives: We used metabolomics analysis to identify metabolic changes and the regulation of inflammatory cytokines in nasal epithelial cells upon influenza virus infection. Material and methods: We cultured nasal epithelial cells using air-liquid interface (ALI) model. Influenza virus (PR8) infection followed by metabolomic analysis was performed. Furthermore, cytokine expression was analyzed by cytokine array and RT-qPCR. Results: Metabolomic analysis revealed depletion of the tryptophan and accumulation of its metabolite, kynurenine, within 48 h. The major enzyme involved in the tryptophan metabolic pathway, indoleamine 2,3-dioxygenase (IDO), was overexpressed after infection. Cytokine expression array after infection showed increased levels of IL-1α, CCL2, IL-6, CXCL10, CCL5, and CXCL11, and after using 1-methyltryptophan (1-MT) as inhibitor, the expression levels of IL-6 and G-CSF were reduced. Conclusions and significance: Viral infection results in depletion of tryptophan and accumulation of kynurenine via increased cellular IDO activity. Inhibition of IDO activity or replenishment of tryptophan by local application may be a good therapeutic strategy for limiting the initial damage caused by influenza virus in nasal epithelial cells. [ABSTRACT FROM AUTHOR]

Background: The role of allergy in the development of chronic rhinosinusitis (CRS) in East Asians is not clear. Aims/objectives: The aim was to investigate the impact of allergies in the clinical characteristics of chronic rhinosinusitis. Material and methods: A total of 138 CRS patients who underwent endoscopic sinus surgery were included. A brief history of rhinosinusitis symptoms, blood eosinophil count, blood-specific allergen tests, computed tomography (CT) scan findings, Lund-Mackay (LM) CT scores, and Sino-Nasal Outcome Test (SNOT-22) Questionnaire scores, and sinoscopy findings at 3 and 6 months postoperatively. Results: The ImmunoCAP test was positive in 71(51%) patients and negative in 67(49%) patients. The mean age of those who received endoscopic sinus surgery was 7-years younger in the allergic group compared with the non-allergic group (p = .008). The peripheral eosinophil count in the allergic group was higher than that of the non-allergic group (p = .008). The LM scores and SNOT-22 scores were not significantly different between the two groups. The recurrence rate of nasal polyps in the allergic group was higher but without statistical significance. Conclusions and significance: Allergy may accelerate the disease progression of CRS. The presence of the serum-specific IgE was correlated with peripheral eosinophil percentage, especially in the CRSwNP patients. [ABSTRACT FROM AUTHOR]

Conclusions. Nasal epithelial cells are constitutively equipped with all Toll-like receptors (TLRs) which are essential for innate immunity. Both mRNA and protein levels of TLR3 expression increased in more differentiated nasal epithelial cells. Considering that the ligand for TLR3 is viral dsRNA, this result is in good accordance with previous reports demonstrating that more differentiated airway epithelial cells have increased resistance to rhinovirus infection. Objective. Nasal epithelial cells use innate immune responses to combat inspired potential pathogens. TLRs are receptors that recognize pathogen-associated molecular patterns of microbes. Therefore, we investigated the expression of TLRs in cultured nasal epithelial cells obtained from nasal polyps. Materials and methods. Submerged single layer (SSL) and air-liquid interface (ALI) nasal epithelial cell cultures with or without 10-7 M retinoid acid (± RA) were created. Results. ALI + RA culture developed ciliary differentiation as observed by light and scanning electron microscopic examination in 3 weeks. It had higher interleukin (IL)-8 basal secretion (21.9 vs 0.82-1.45 ng/ml) and transepithelial potential (-20.4 mV). TLR1-10 mRNA expression in cultured nasal epithelial cells was determined by RT-PCR. Only TLR3 mRNA significantly increased at day 20 vs day 1 (n=5, p=0.02) in ALI + RA cell culture. Higher TLR3 protein was also expressed at day 20 in ALI + RA cell culture but not in SSL culture by western blotting. [ABSTRACT FROM AUTHOR]