title: Th17responses are not altered by natural exposure to seasonal allergens in pollen-sensitive patients.
abstract: BACKGROUND
  Allergic rhinitis affects 10-30 % of the global population and this number is likely to increase in the forthcoming years. Moreover, it commonly co-exists with allergic asthma as a chronic allergic respiratory syndrome. While the involvement of Th2cells in allergy is well understood, alterations of pro-inflammatory Th17responses remain poorly characterized. The aim of our study was to determine whether natural seasonal allergen exposure causes changes in T cell subset characteristics in patients with allergic rhinitis and asthma.
  
  
  METHODS
  Sixteen patients with allergic rhinitis/atopic asthma (9M, 7F; age 31.8 ± 12.1) and 16 healthy controls were recruited into the study (9M, 7F; age 31.2 ± 5.3). Blood samples were collected from the patients 1-3 months before pollen season (visit 1), within 7 days of the appearance of pollen/initiation of allergic symptoms (visit 2) and 2 weeks after visit 2 following the introduction of symptomatic treatment with antihistamines (visit 3). Flow cytometry was used to assess major T cell subsets (naïve, central memory, effector memory and CD45RA+ effector) and key T cell cytokine production (IFNγ, IL-17A, TNF and IL-4) using intracellular staining. Data were analyzed using repeated measures ANOVA and paired t test.
  
  
  RESULTS
  As expected, an increase in the percentage of IL-4+ CD4+ cells was observed during natural pollen exposure in patients with allergic respiratory syndrome. No significant changes were observed in the production of other cytokines, including Th17cells, which tended to be lower than in the control population but unchanged during pollen exposure. Introduction of antihistamine treatment led to only moderate changes in cytokine production from CD4 and CD8 T cells. Selective changes in CD8+ T cells were observed during natural pollen exposure including a decrease in transient cells (with features of CD45RA+ and CD45RO+ cells) and a decrease in the percentage of central memory cells in the peripheral circulation. Within the CD4 cell group the total percentage of CD45RA positive CD4 cells was increased during pollen exposure.
  
  
  CONCLUSIONS
  Th1and Th17responses are not altered during pollen season but allergen exposure affects T cell activation and memory cell status in patients with allergic respiratory syndrome.
authors: Translational Medicine Laboratory, Department of Internal and Agricultural Medicine, School of Medicine, Jagiellonian University, Skarbowa 1, 31-121 Cracow, Poland.
authors: Agata
authors: A
authors: Schramm
authors: Translational Medicine Laboratory, Department of Internal and Agricultural Medicine, School of Medicine, Jagiellonian University, Skarbowa 1, 31-121 Cracow, Poland.
authors: Barbara
authors: B
authors: Jasiewicz-Honkisz
authors: Translational Medicine Laboratory, Department of Internal and Agricultural Medicine, School of Medicine, Jagiellonian University, Skarbowa 1, 31-121 Cracow, Poland.
authors: Grzegorz
authors: G
authors: Osmenda
authors: Translational Medicine Laboratory, Department of Internal and Agricultural Medicine, School of Medicine, Jagiellonian University, Skarbowa 1, 31-121 Cracow, Poland.
authors: Grzegorz
authors: G
authors: Wilk
authors: Translational Medicine Laboratory, Department of Internal and Agricultural Medicine, School of Medicine, Jagiellonian University, Skarbowa 1, 31-121 Cracow, Poland.
authors: Mateusz
authors: M
authors: Siedlinski
authors: Translational Medicine Laboratory, Department of Internal and Agricultural Medicine, School of Medicine, Jagiellonian University, Skarbowa 1, 31-121 Cracow, Poland ; Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK.
authors: Agnieszka
authors: A
authors: Sagan
authors: Translational Medicine Laboratory, Department of Internal and Agricultural Medicine, School of Medicine, Jagiellonian University, Skarbowa 1, 31-121 Cracow, Poland.
authors: Pawel T
authors: PT
authors: Matusik
authors: Translational Medicine Laboratory, Department of Internal and Agricultural Medicine, School of Medicine, Jagiellonian University, Skarbowa 1, 31-121 Cracow, Poland.
authors: Joanna
authors: J
authors: Maciag
authors: Translational Medicine Laboratory, Department of Internal and Agricultural Medicine, School of Medicine, Jagiellonian University, Skarbowa 1, 31-121 Cracow, Poland.
authors: Tomasz
authors: T
authors: Sliwa
authors: Department of Dental Prophylaxis and Experimental Dentistry, Dental School, Jagiellonian University, Cracow, Poland ; Oral Sciences Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
authors: Marta
authors: M
authors: Czesnikiewicz-Guzik
authors: Translational Medicine Laboratory, Department of Internal and Agricultural Medicine, School of Medicine, Jagiellonian University, Skarbowa 1, 31-121 Cracow, Poland ; Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK.
authors: Tomasz P
authors: TP
authors: Mikolajczyk
keywords: Allergy; Cytokines; Memory cells; Rhinitis