title: Role of the frequency of blood CD4(+) CXCR5(+) CCR6(+) T cells in autoimmunity in patients with Sjögren's syndrome.
abstract: The blood CD4(+) CXCR5(+) T cells, known as "circulating" Tfh, have been shown to efficiently induce naïve B cells to produce immunoglobulin. They play an important role in certain autoimmune diseases. In the present study, we show for the first time that the frequency of CD4(+) CXCR5(+) T cells is increased in pSS patients and positively correlated with autoantibodies in the blood. The concentration of Th17-like subsets (CD4(+) CXCR5(+) CCR6(+)) in pSS patients was found to be significantly higher than in healthy controls. Functional assays showed that activated Th17-like subtypes in the blood display the key features of Tfh cells, including invariably coexpressed PD-1, ICOS, CD40L and IL-21. Th17 subsets were found to highly express Bcl-6 protein and Th1 and Th2 were not. Bcl-6 is believed to be a master transforming factor for Tfh cell differentiation and facilitate B cell proliferation and somatic hypermutation within the germinal center. These data indicate that Th17 subsets of CD4(+) CXCR5(+) T cells in the blood may participate in the antibody-related immune responses and that high frequency of CD4(+) CXCR5(+) CCR6(+) Tfh cells in blood may be suitable biomarkers for the evaluation of the active immune stage of pSS patients. It might provide insights into the pathogenesis and perhaps help researchers identify novel therapeutic targets for pSS.
authors.affiliation: Department of Clinical Immunology, State key Discipline of Cell Biology, Xi-jing Hospital, Fourth Military Medical University, Shaanxi Province, PR China.
authors.forename: Xue-yi
authors.initials: XY
authors.lastname: Li
authors.forename: Zhen-biao
authors.initials: ZB
authors.lastname: Wu
authors.forename: Jin
authors.initials: J
authors.lastname: Ding
authors.forename: Zhao-hui
authors.initials: ZH
authors.lastname: Zheng
authors.forename: Xiao-yan
authors.initials: XY
authors.lastname: Li
authors.forename: Li-na
authors.initials: LN
authors.lastname: Chen
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
mesh_terms: D015551:Autoimmunity; D015704:CD4 Antigens / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D005260:Female; D006801:Humans; D007378:Interleukins / Q000096:biosynthesis; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D051560:Proto-Oncogene Proteins c-bcl-6; D054399:Receptors, CCR6 / Q000276:immunology*; D054380:Receptors, CXCR5 / Q000276:immunology*; D012859:Sjogren's Syndrome / Q000097:blood / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology*; D000098546:Interleukin-21
chemical_list: C084103:BCL6 protein, human; C106311:CCR6 protein, human; D015704:CD4 Antigens; C095085:CXCR5 protein, human; D004268:DNA-Binding Proteins; D007378:Interleukins; D051560:Proto-Oncogene Proteins c-bcl-6; D054399:Receptors, CCR6; D054380:Receptors, CXCR5; D000098546:Interleukin-21