title: Phenotypic characterization of ex vivo CD4+CD25highCD127low immune regulatory T cells in allergic asthma: pathogenesis relevance of their FoxP3, GITR, CTLA-4 and FAS expressions.
abstract: BACKGROUND
  CD4+CD25high regulatory T (Treg) cells are crucial for immune homeostasis and peripheral tolerance, but their relevance to allergic asthma has not been fully elucidated.
  
  
  OBJECTIVE
  To assess peripheral blood CD4+ T cells, and CD4+CD25highCD127low Treg cells expressing phenotypic markers (FoxP3, GITR, CTLA-4, and FAS) in allergic asthma subjects.
  
  
  METHODS
  Peripheral blood mononuclear cells were isolated from 60 allergic asthma (AA) subjects and 30 healthy controls (HC). We examined by flow cytometry, the proportion of CD4+ T cells and CD4+CD25highCD127low Treg cells as well as the expression of FoxP3, GITR, CTLA-4, and FAS by CD4+CD25highCD127low Treg cells. Moreover, FOXP3 mRNA expression was measured by quantitative real time polymerase chain reaction (real-time RT-PCR).
  
  
  RESULTS
  The absolute number of CD4+CD25highCD127low Treg cells and the percentages of CD4+CD25highCD127low Treg cells expressing one of the four selected markers were significantly lower in allergic asthma subjects compared with controls. We observed no significant decreased absolute CD4+ T cell count in the examined groups compared to the control group. Except for GITR, circulatory CD4+CD25highCD127low Treg cells of severe allergic asthma (SA) subjects showed significantly lower expressions of FoxP3, CTLA-4, and CD95 than did those isolated from mild to moderate asthma (MA) patients. There was no statistically significant difference in the level of mRNA FoxP3 expression in CD4+CD25+ Treg cells between allergic asthma subjects and healthy controls groups, and within the examined groups (p>0.05).
  
  
  CONCLUSIONS
  These findings suggest that allergic asthma and the use of glucocorticosteroids are associated with decreased absolute number of circulatory CD4+CD25highCD127low Treg cells and the decreased frequencies of CD4+CD25highCD127low Treg cells expressing one of the four selected markers.
authors.affiliation: Department of Laboratory Diagnostics, Medical University of Lodz, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Pietruczuk
authors.forename: M
authors.initials: M
authors.lastname: Eusebio
authors.forename: L
authors.initials: L
authors.lastname: Kraszula
authors.forename: M
authors.initials: M
authors.lastname: Kupczyk
authors.forename: P
authors.initials: P
authors.lastname: Kuna
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000188:drug therapy / Q000276:immunology*; D018791:CD4 Lymphocyte Count; D060908:CTLA-4 Antigen / Q000097:blood*; D005260:Female; D051858:Forkhead Transcription Factors / Q000097:blood* / Q000235:genetics; D053450:Glucocorticoid-Induced TNFR-Related Protein / Q000097:blood*; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D016130:Immunophenotyping; D053699:Interleukin-7 Receptor alpha Subunit / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D019014:fas Receptor / Q000097:blood*
chemical_list: D060908:CTLA-4 Antigen; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053450:Glucocorticoid-Induced TNFR-Related Protein; D005938:Glucocorticoids; D053699:Interleukin-7 Receptor alpha Subunit; D012333:RNA, Messenger; C491405:TNFRSF18 protein, human; D019014:fas Receptor