title: p-STAT6, PU.1, and NF-κB are involved in allergen-induced late-phase airway inflammation in asthma patients.
abstract: BACKGROUND
  Previous in vitro and animal studies demonstrated that transcription factors p-STAT6 and PU.1 are required to induce interleukin (IL)-9 secretion by T helper (Th) 9 cells. It is believed that n factor-kappaB (NF-κB) plays a role in eosinophil survival. The importance of these transcription factors in the pathogenesis of allergic asthma (AA) in humans is poorly understood. We evaluated p-STAT6 and PU.1 expression in peripheral blood Th9 cells and NF-κB expression in eosinophils during late-phase airway inflammation in AA patients.
  
  
  METHODS
  Nineteen adults with AA and 14 adult healthy individuals (HI) were examined. Peripheral blood collected 24 h before (baseline) and 24 h after bronchial allergen challenge. CD4(+) cells and eosinophils were isolated by high-density gradient centrifugation and magnetic separation. The percentage of Th9 cells and apoptotic eosinophils was estimated by flow cytometry. p-STAT6 and PU.1 expression was expressed as mean fluorescence intensity (MFI) in Th9 cells. NF-κB levels were expressed as MFI in peripheral blood eosinophils. Serum IL-9 and IL-5 levels were determined by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  At baseline, MFI of p-STAT6 and PU.1 in peripheral blood Th9 cells and MFI of NF-κB in eosinophils and, serum IL-5 and IL-9 levels were greater in AA patients (P < 0.05). Decreased eosinophil apoptosis was seen in the AA group compared with HI (P < 0.05). MFI of p-STAT6, PU.1, and NF-κB and serum levels of IL-5 and IL-9 were increased in the AA group 24 h after challenge compared with baseline (P < 0.05). In the AA group, a correlation between serum IL-9 and Th9 cells (r = 0.7, P = 0.001) and MFI of PU.1 (r = 0.6, P = 0.01) 24 h after bronchial allergen challenge was observed. A correlation between Th9 cells and MFI of p-STAT6 (r = 0.45, P = 0.03) as well as MFI of PU.1 (r = 0.5, P = 0.02) 24 h after challenge was only observed in AA patients. A correlation between the MFI of NF-κB and eosinophil apoptosis was observed in AA patients 24 h before (r = - .46, P = 0.02) and after (r = -0.5, P = 0.02) challenge.
  
  
  CONCLUSIONS
  p-STAT6 and PU.1 may be associated with Th9 cells and IL-9 production, whereas NF-κB and IL-5 may be associated with reduced eosinophil apoptosis in allergen-induced late-phase airway inflammation.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT02214303.
authors.affiliation: Department of Pulmonology and Immunology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania. deimante@gmail.com.
authors.forename: Deimante
authors.initials: D
authors.lastname: Hoppenot
authors.affiliation: Department of Pulmonology and Immunology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania. kestutis.malakauskas@lsmuni.lt.|Laboratory of Pulmonology, Department of Pulmonology and Immunology, Medical Academ, Lithuanian University of Health Sciences, Kaunas, Lithuania. kestutis.malakauskas@lsmuni.lt.
authors.forename: Kestutis
authors.initials: K
authors.lastname: Malakauskas
authors.affiliation: Department of Pulmonology and Immunology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania. lavinskiene.simona@gmail.com.|Laboratory of Pulmonology, Department of Pulmonology and Immunology, Medical Academ, Lithuanian University of Health Sciences, Kaunas, Lithuania. lavinskiene.simona@gmail.com.
authors.forename: Simona
authors.initials: S
authors.lastname: Lavinskiene
authors.affiliation: Department of Pulmonology and Immunology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania. raimundas.sakalauskas@kaunoklinikos.lt.
authors.forename: Raimundas
authors.initials: R
authors.lastname: Sakalauskas
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000276:immunology*; D001985:Bronchial Provocation Tests; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D004804:Eosinophils / Q000276:immunology; D005260:Female; D006801:Humans; D015848:Interleukin-5 / Q000276:immunology*; D016906:Interleukin-9 / Q000276:immunology*; D008297:Male; D016328:NF-kappa B / Q000276:immunology*; D010750:Phosphoproteins / Q000276:immunology; D011518:Proto-Oncogene Proteins / Q000276:immunology*; D012130:Respiratory Hypersensitivity / Q000276:immunology*; D050800:STAT6 Transcription Factor / Q000276:immunology*; D012882:Skin Tests; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D015534:Trans-Activators / Q000276:immunology*; D055815:Young Adult; D000099232:Proto-Oncogene Protein Spi-1
chemical_list: D015848:Interleukin-5; D016906:Interleukin-9; D016328:NF-kappa B; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D050800:STAT6 Transcription Factor; D015534:Trans-Activators; D000099232:Proto-Oncogene Protein Spi-1; C508599:IL5 protein, human; C508607:IL9 protein, human; C494101:STAT6 protein, human