Flow Cytometry Analysis of Peripheral Blood B Cell Distribution of Patients with Multiple Sclerosis

Abstract

Objective: Multiple sclerosis (MS) is a central nervous system (CNS) disease characterized by autoimmune inflammation and neurodegeneration. Damage to the CNS is thought to be mediated predominantly by activated pro-inflammatory T cells and antibody secreting B cells. Strong evidence of B cell functions in MS pathogenesis has come from trials of B cell-depleting treatment. In this study, the peripheral blood frequencies of B cell subsets were measured using flow cytometry in patients to determine the disease-specific B cell differences that might be associated with the evolution to progressive forms of MS. Materials and Methods:Peripheral blood mononuclear cells were separated from patients and healthy controls [relapsing-remitting MS (RRMS) and secondary progressive MS (SPMS)]. Cells were stained with anti-human monoclonal antibodies (CD19-APC, CD27-FITC, IgD-APC/Cy7, CD138-PE, CD24-PerCP and CD38-Alexa fluor 700), and analyzed using flow cytometry.Results: There were no significant differences between the MS group and healthy controls by means of peripheral blood frequencies of B cells, immature, naïve, classic memory, plasma, plasmablasts, and regulatory B cells. Only higher naïve B cell frequency tendency was determined in patients with RRMS as compared with patients with SPMS and healthy controls. Conclusion:Peripheral blood B cell subset measurements are not likely to be used as a biomarker for prediction of disease progression. Although B cells have a well-known pathogenic significance, B cell population alterations do not occur during the progression of the disease. Keywords: Multiple sclerosis, B cell, peripheral bloodAmaç: Multipl skleroz (MS), bir merkezi sinir sistemi hastalığıdır ve otoimmün inflamasyon ve nörodejenerasyon ile karakterizedir. Hastalıkta aktif olan enflamasyon ve proinflamatuar T hücresi dışında antikor yapan B hücrelerinin de rolü büyüktür. Periferik B hücrelerinin MS hastalığındaki rolü, B hücrelerinin deplesyonu ile elde edilen bulgulara dayanmaktadır. Çalışmamızda periferik kandaki B hücre alt tiplerinin akım sitometrisi ile belirlenmesi ve hastalık alt gruplarındaki olası farklarının belirlenmesi hedeflendi. Gereç ve Yöntem: MS hasta grubu [relapsing-remitting MS (RRMS) ve sekonder progresif MS (SPMS)] ve sağlıklı donörlerden periferik kan mononükleer hücreleri izole edildi. Bu hücreler, B hücresine spesifik monoklonal antikorlar ile (CD19-APC, CD27-FITC, IgD-APC/Cy7, CD138-PE, CD24-PerCP ve CD38-Alexa fluor 700) işaretlendi ve akım sitometrisi ile değerlendirildi. Abstract Öz 219Original Article / Özgün Araştırma DO I:10.4274/tnd.87523 Turk J Neurol 2017;23:219-224

Impaired TIGIT expression on B cells drives circulating follicular helper T cell expansion in multiple sclerosis

“…On the other hand, TIGIT + B cells expressed little CD38 after stimulation, which suggests that TIGIT expression was transient and disappeared after the differentiation of plasmablasts. There were no differences between the proportions of these B cell subsets when comparing cells from patients with MS and healthy controls ( 21 , 36 ) ( Supplemental Figure 2C ), and, similarly, no differences were observed in the expression levels of the transcription factors IRF4 , PRDM1 , and XBP1 with regard to the plasmablast developmental program ( 37 , 38 ) ( Supplemental Figure 2D ). Thus, the differentiation of plasmablasts suppressed TIGIT expression on B cells, and this signature was unrelated to the downregulation of TIGIT expression on MS-derived B cells.…”