title: Low responder T cell susceptibility to the suppressive function of regulatory T cells in patients with dilated cardiomyopathy.
abstract: OBJECTIVE
  The pathogenesis of dilated cardiomyopathy (DCM) is closely connected with dysfunction of the autoimmune system, and CD4(+)CD25(high)CD127(low/-) regulatory T (Treg) cells have a vital role in maintaining self-tolerance. In this study, we compared the frequency and regulatory function of Treg cells between DCM patients and normal controls.
  
  
  RESULTS
  The frequencies of CD4(+)CD25(+) T cells in DCM patients were statistically decreased compared with normal controls (p<0.05) by flow cytometry, and the levels of FOXP3 mRNA and protein expression in PBMCs (peripheral blood mononuclear cells) of DCM patients were lower than those of normal controls (p<0.01), using real-time RT-PCR assay and western blot. Notably, the suppressive capacity of CD4(+)CD25(high)CD127(low/-) regulatory T cells of DCM patients acting on autologous CD4(+)CD25(-) responder T (Tresp) cells seemed to be partially impaired (43.83+/-3.19% suppression versus 63.17+/-3.66% in normal controls, p=0.01). Surprisingly, Treg cells from DCM patients efficiently suppressed the proliferation of Tresp cells from normal subjects to the similar level as Treg cells from normal subjects on autologous Tresp cells (p=0.286), whereas Treg cells of normal subjects poorly inhibited the proliferation of Tresp cells from DCM patients.
  
  
  CONCLUSIONS
  The defective capacity of Treg cells suppressing autologous Tresp cells is attributed to the increasing resistance of Tresp cells to inhibition of Treg cells in DCM patients. Therefore, strategies to improve the susceptibility of Tresp cells to Treg cell-mediated suppression might benefit DCM patients.
authors.affiliation: Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jie-Fang Avenue, Wuhan, 430022, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Tang
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Zhong
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Zhu
authors.forename: Fang
authors.initials: F
authors.lastname: Zhao
authors.forename: Xiaoxue
authors.initials: X
authors.lastname: Cui
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D005260:Female; D051858:Forkhead Transcription Factors / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000097:blood; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D017634:Self Tolerance / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; C508017:IL2RA protein, human; D053645:Interleukin-2 Receptor alpha Subunit; D012333:RNA, Messenger