title: Variation of T-cell activation in allergic subjects during natural pollen exposure.
abstract: BACKGROUND
  Allergic inflammation is characterized by a Th2 activation. However, little is known about dynamics of T-cell cytokine production during natural allergen exposure. The aim of this study was to assess the Th1/Th2 balance in cypress allergic patients compared with controls, and variations of this balance over the pollen season.
  
  
  METHODS
  Twenty cypress allergic patients and 10 controls were studied, distributed during two consecutive pollen seasons. Cytokine production was assessed by flow cytometry and ELISA. The variation of cytokine production during the pollen season was analyzed among patients in four occasions, and the preseason values were compared with controls. IL-13 and IFN-gamma-containing T cells were assessed among whole blood cells and PBMC. In addition the effect of specific stimulation by Juniperus ashei pollen extract was studied.
  
  
  RESULTS
  Compared with controls, IL-13-producing T cells were increased in allergics in any case. By contrast, compared with controls, allergic IFN-gamma-producing T cells were decreased in whole blood, but not in PBMC, and were increased after specific stimulation. During the season, an increase in IFN-gamma- and a decrease in IL-13-producing T cells occurred in patients, whatever the culture conditions.
  
  
  CONCLUSIONS
  These results show that the allergic T-cell activation is not limited to a Th2 profile: allergen-stimulated T cells are able to produce IFN-gamma at baseline, and the Th1/Th2 ratio increases during the pollen season.
authors.affiliation: Faculté de Médecine de Marseille, Université de la Méditerranée, Assistance Publique Hôpitaux de Marseille, Service de Pneumo-Allergologie, INSERM, Marseilles, France.
authors.forename: V
authors.initials: V
authors.lastname: Koscher
authors.forename: F
authors.initials: F
authors.lastname: Milhe
authors.forename: M
authors.initials: M
authors.lastname: El Biaze
authors.forename: D
authors.initials: D
authors.lastname: Vervloet
authors.forename: A
authors.initials: A
authors.lastname: Magnan
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis / Q000276:immunology; D018793:Interleukin-13 / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011058:Pollen / Q000009:adverse effects / Q000276:immunology*; D011336:Probability; D012016:Reference Values; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology* / Q000503:physiopathology; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018418:Th2 Cells / Q000276:immunology* / Q000502:physiology
chemical_list: D016207:Cytokines; D018793:Interleukin-13