title: Analysis of T-helper responses and FOXP3 gene expression in patients with Japanese cedar pollinosis.
abstract: BACKGROUND
  Evidence has been accumulated indicating that regulatory T (T-reg) cells play a crucial role in the maintenance of peripheral T-cell tolerance to allergens. To explore the role of FOXP3, which is required for the development of T-reg cells, in allergen-specific immune responses, we examined the relationship between the alteration of FOXP3 gene expression and in vitro immune responses against allergens.
  
  
  METHODS
  Peripheral blood mononuclear cells obtained from 19 human histocompatibility leukocyte antigens (HLA)-DPB1*0501 donors, including patients with Japanese cedar pollinosis and nonallergic healthy donors, were stimulated with Cry j 1 p61-75 peptide. On day 7, T cells were tested for peptide-specific reactivity in IFN-gamma and interleukin (IL)-5 enzyme-linked immunospot (ELISPOT) assays. Real-time quantitative RT-PCR was performed to assess relative change of FOXP3 gene expression before and after in vitro stimulation. Neutralization assays using anti-glucocorticoid-induced tumor necrosis factor receptor family-related protein (GITR) and anti-IL-10 monoclonal antibody were also performed.
  
  
  RESULTS
  Of 14 patients with allergic pollinosis tested, 10 responders displayed T-helper type 2 (Th2)-polarized reactivity to Cry j 1 p61-75, and 2 donors showed Th0 responses. Notably, the change of FOXP3 gene expression in donors showing peptide-specific T-helper responses was significantly lower than that in nonresponders, regardless of allergic pollinosis.
  
  
  CONCLUSIONS
  Our data indicate that FOXP3 is functional in nonallergic healthy donors as well as allergic patients, and FOXP3-expressing T cells may be responsible for the down-regulation of allergen-specific T-helper responses in individuals. A better understanding of the nature and specificity of FOXP3-expressing T cells in a suppressive mechanism is necessary to develop new immunotherapies against allergic rhinitis.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Gunma University Graduate School of Medicine, Gunma, Japan. chikamatsu@yamanashi.ac.jp
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chikamatsu
authors.forename: Koichi
authors.initials: K
authors.lastname: Sakakura
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Matsuoka
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Endo
authors.forename: Goro
authors.initials: G
authors.lastname: Takahashi
authors.forename: Zensei
authors.initials: Z
authors.lastname: Matsuzaki
authors.forename: Keisuke
authors.initials: K
authors.lastname: Masuyama
mesh_terms: D000328:Adult; D032485:Cryptomeria; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics*; D015870:Gene Expression; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis; D015848:Interleukin-5 / Q000032:analysis; D008297:Male; D008875:Middle Aged; D020133:Reverse Transcriptase Polymerase Chain Reaction; D006255:Rhinitis, Allergic, Seasonal / Q000235:genetics* / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D015848:Interleukin-5; D007371:Interferon-gamma