title: Regulatory T cells fail to suppress CD4T+-bet+ T cells in relapsing multiple sclerosis patients.
abstract: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system and a defect in the regulatory T-cell subset seems to be involved in the pathogenesis of the disease. Foxp3 is a transcription factor that is selectively expressed in CD4+ CD25+ regulatory T cells and is required for their development and function. T-bet is a key transcription factor for the development of T helper 1 (Th1) cells. We found that both the percentage of circulating CD4+ CD25+ Foxp3+ cells and Foxp3 expression were lower in relapsing-remitting (RR) MS patients during relapses than during remission. Otherwise, the percentage of CD4+ T-bet+ T cells and T-bet expression in CD4+ T cells were higher in relapsing than in remitting RRMS patients. CD4+ CD25+ T cells both from relapsing and from remitting RRMS patients showed significantly less capacity than corresponding cells from healthy subjects to suppress autologous CD4+ CD25(-) T-cell proliferation, despite a similar Foxp3 expression level. CD4+ CD25+ T cells from healthy subjects and patients in remission clearly reduced T-bet mean fluorescence intensity (MFI) in CD4+ CD25(-) T cells up to a ratio of 1:10, whereas CD4+ CD25+ T cells from patients in relapse were able to reduce T-bet expression only at a high ratio. Our data indicate that the increased number of regulatory T (T-reg) cells and the increased Foxp3 expression in circulating CD4+ CD25+ T cells may contribute to the maintenance of tolerance in the remission phase of MS. Moreover, the inhibitory capacity of CD4+ CD25+ T cells seems to be impaired in relapsing patients under inflammatory conditions, as shown by the high levels of T-bet expression in CD4+ T cells.
authors.affiliation: Department of Neuroscience, Institute of Neurology, Catholic University, Rome.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Frisullo
authors.forename: Viviana
authors.initials: V
authors.lastname: Nociti
authors.forename: Raffaele
authors.initials: R
authors.lastname: Iorio
authors.forename: Agata K
authors.initials: AK
authors.lastname: Patanella
authors.forename: Marcella
authors.initials: M
authors.lastname: Caggiula
authors.forename: Alessandro
authors.initials: A
authors.lastname: Marti
authors.forename: Cristina
authors.initials: C
authors.lastname: Sancricca
authors.forename: Francesco
authors.initials: F
authors.lastname: Angelucci
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Mirabella
authors.forename: Pietro A
authors.initials: PA
authors.lastname: Tonali
authors.forename: Anna P
authors.initials: AP
authors.lastname: Batocchi
mesh_terms: D000293:Adolescent; D000328:Adult; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D007108:Immune Tolerance; D053645:Interleukin-2 Receptor alpha Subunit / Q000097:blood; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000276:immunology*; D020825:T-Box Domain Proteins / Q000097:blood*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*; D015854:Up-Regulation / Q000276:immunology; D055815:Young Adult; D000098815:T-bet Transcription Factor
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor