B cells in multiple sclerosis therapy—A comprehensive review

For decades, B cells were ignored in multiple sclerosis (MS) pathogenesis, and the disease was always regarded as a T cell‐mediated disorder. Recent evidence shows that there is an antigen‐driven B‐cell response in the central nervous system of patients with MS, and memory B cells/plasma cells are detectable in MS lesions. The striking efficacy of B cell‐depleting therapies in reducing the inflammatory activity of the disease highlights that B cells may play more pathogenetic roles than expected. B cells express several unique characteristic markers on their surface, for example, CD19, CD20 molecules, that provide selective targets for monoclonal antibodies. In this respect, several B cell‐targeted therapies emerged, including anti‐CD20 antibodies (rituximab, ocrelizumab, and ofatumumab), anti‐CD19 antibody (inebilizumab), and agents targeting the BAFF/APRIL signaling pathway (atacicept, belimumab, and LY2127399). In this review, we discuss, in detail, the immunobiology of B cells and their protective and destructive roles in MS pathogenesis. In the second part, we list the completed and ongoing clinical trials investigating the safety and efficacy of B cell‐related monoclonal antibodies in MS.     

Invited article: inhibition of B cell functions: implications for neurology

B cells are involved in the pathophysiology of many neurologic diseases, either in a causative or contributory role, via production of autoantibodies, cytokine secretion, or by acting as antigen-presenting cells leading to T cell activation. B cells are clonally expanded in various CNS disorders, such as multiple sclerosis (MS), paraneoplastic CNS disorders, or stiff-person syndrome, and are activated to produce pathogenic autoantibodies in demyelinating neuropathies and myasthenia. B cell activating factor (BAFF) and a proliferating inducing ligand (APRIL), key cytokines for B cell survival, are strongly unregulated in MS brain and in muscles of inflammatory myopathies. Modulation of B cell functions using a series of monoclonal antibodies against CD20+ B cells or the molecules that increase B cell survival, such as BAFF/APRIL and their receptors BAFF-R, TACI, and BCMA, provide a rational approach to the treatment of the aforementioned neurologic disorders. In controlled studies, rituximab, a B cell-depleting monoclonal antibody, has been encouraging in MS and paraproteinemic anti-MAG demyelinating neuropathy, exerting long-lasting remissions. In uncontrolled series, benefit has been reported in several disorders. B cell depletion is a well-tolerated therapeutic option currently explored in the treatment of several autoimmune neurologic disorders.     

Analysis of BAFF and TRAIL expression levels in multiple sclerosis patients: evaluation of expression under immunomodulatory therapy

Kurne A, Guc D, Canpinar H, Aydin ÖF, Sayat G, Yörübulut M, Esendagli G, Karabudak R. Analysis of BAFF and TRAIL expression levels in multiple sclerosis patients: evaluation of expression under immunomodulatory therapy.
Acta Neurol Scand: 2011: 123: 8–12.
© 2010 The Authors Journal compilation © 2010 Blackwell Munksgaard. Objectives – Tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) and B cell‐activating factor (BAFF), the members of tumor necrosis factor superfamily, play essential roles in immune homeostasis and may have potential contributions to the autoimmune process in multiple sclerosis (MS). Material and methods – Thirty‐five relapsing remitting MS (RRMS) patients and 19 healthy individuals were enrolled in the study. The expression of TRAIL on peripheral blood lymphocytes was analyzed by flow cytometry. The serum levels of soluble TRAIL (sTRAIL) and soluble BAFF (sBAFF) were determined by ELISA. Further, we evaluated the effect of IFN‐β on sTRAIL, sBAFF levels and on TRAIL surface expression in these patients on the third and sixth months following the treatment. Results and conclusion – These preliminary results signify that MS patients are heterogenous in TRAIL expression. Additionally, during the IFN‐β treatment, the soluble form of TRAIL increases concomitantly as its surface expression decreases on lymphocytes. The basal sBAFF levels of patients were significantly higher than the control group and no significant change was observed. Thus, the changes in TRAIL expression may be a potential parameter indicating the response to IFN‐β1 therapy at individual level.     

地黄合剂在多发性硬化患者中抗炎性反应及调节免疫平衡机制探讨

目的 观察地黄合剂(DHHJ)在多发性硬化(MS)患者中发挥的双向治疗作用并探讨其机制. 方法 将40例MS患者采用随机数字表法分为激素治疗组(n=20)与激素治疗+DHHJ组(n=20),根据组名采取相应治疗.另设20例排除免疫系统疾病及感染类疾病的外科手术患者作为对照组.分别用EUSA法和流式细胞仪检测两组观察对象脑脊液(CSF)和外周血中胶质原纤维酸性蛋I~(GFAP)和S100B的含量及CD4+细胞,CD8+细胞数目.用下肢功能状态的评分(AD、延展残疾状态评分(EDSS)、上肢功能状态评分(9HPT)对MS患者进行临床评分并分析其与GFAP、S100B之间的关系.随访MS患者的复发情况. 结果 与对照组比较.MS组CSF中GFAP和S100B表达明显增强,差异有统计学意义(P<0.05),并且与MS患者的AI、9HPT评分存在相关关系.DHHJ+激素治疗组与激素治疗组患者CSF中GFAP和S100B含量差异也有统计学意义(P<0.05).同时DHHJ+激素治疗组MS的复发次数与激素治疗组比较差异也有统计学意义(P<0.05).MS患者的外周血和CSF中出现CD4+细胞明显增多,CD8+细胞明显减少;CSF中更明显.给予不同的治疗后.CD4+细胞数目减少.CD8+细胞数目增多,DHHJ+激素治疗组与激素治疗组之间差异有统计学意义(p<0.05). 结论 DHHJ 一方面能够影响MS患者CSF中GFAP和S100B的表达,抑制胶质细胞的激活,达到抗炎性反应作用;另一方面DHHJ还可以通过上调免疫抑制性CD8+细胞的数目,下调免疫辅助性CD4+细胞,发挥调节免疫平衡作用,最终达到双向治疗MS的作用,减少MS患者复发的次数.     

CD5 B cells and CD48 T cells in neuroimmunological diseases

Using 2- and 3-colour FACS analysis we found increased levels of fetal-type CD5+ B cells and CD4-8- T cells in cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) and aseptic meningitis (AM) compared to control probands with muscular tension headache (TH). Similar differences were found for CD5+ B cells in peripheral blood, but at lower levels. CD4-8- T cells in blood exceeded those in CSF in all patient groups, with the exception of relapsing remitting MS, revealing the highest values in AM. There was a positive correlation between CD4-8- T cells and T cell receptor (TCR) gamma delta bearing T cells in blood and CSF. The double-negative T cells exceeded the TCR gamma delta T cells by about 1%. A positive correlation between CD5+ B cells and CD4-8- T cell level in CSF was found in MS and AM, but not in TH, nor in blood of any patient group. HLA-DR expression was lower in CD5+ B cells than in CD5- B cells. We conclude that fetal-type lymphocytes are enriched in CSF compartment of patients with inflammatory diseases of the central nervous system, irrespective of autoimmune mechanisms involved, but the function of CD5+ B cells is mainly to produce the autoantibodies.     

T-cell phenotypic profiles in the cerebrospinal fluid and peripheral blood of multiple sclerosis patients.

Thirty-nine patients with clinically definite multiple sclerosis (MS) entered the study. Of 28 subjects with a relapsing-remitting course, 19 were classified in acute relapse, 9 in remission; 11 patients had a progressive course without remissions. Furthermore, 6 subjects with inflammatory neurological disease (IND), and 10 with non-inflammatory and non-neoplastic neurological disease (NIND) were investigated. We simultaneously studied cerebrospinal fluid (CSF) and peripheral blood (PB) T-, B- and NK-cell subsets, as defined by following monoclonal antibodies: anti-CD3, -CD4, -CD8, -CD19, -CD16, -HLA-DR and -IL-2-R. We found a significant increase of CD4+ T-cells compared with controls in CSF, with respect to PB, of MS patients, particularly in acute relapse. An increase of HLA-DR+ cell percentages in the CSF than in the PB in all MS groups, especially in attacks of MS but also in remission, was also observed, with a positive correlation between CD4+ T-cell and DR+ cell percentages both in the CSF as well as in the PB of relapsing MS patients. These findings, together with the increase of IL-2-R+ cells in the PB, particularly in relapsing MS, give further support for the presence of a systemic T-cell activation in MS.     

B‐cell–activating factor is elevated in serum of patients with myasthenia gravis

Introduction: Myasthenia gravis (MG) is a B‐cell–mediated autoimmune disease. B‐cell–activating factor (BAFF) is a major factor in B‐cell development and activation. In this study we investigated serum BAFF levels in MG patients. Methods: We compared the serum BAFF levels of 20 MG patients with gender‐matched healthy controls. We assayed serum concentrations of BAFF and anti‐acetylcholine receptor antibody (AChR) titers. Results: Serum BAFF levels of MG patients with AChR antibodies were significantly higher than those of healthy controls. A significant positive correlation was observed between serum BAFF levels and anti‐AChR antibody titers. BAFF values did not correlate with disease severity. Conclusions: BAFF may play a major role in the pathogenesis of MG, and it may provide a potential target for therapy in patients with MG. Muscle Nerve 54 : 1030–1033, 2016     

CD95/Fas expression on peripheral blood T lymphocytes in patients with multiple sclerosis: effect of high-dose methylprednisolone therapy

Recent data indicate that the apoptotic process, mediated by the CD95/Fas cell surface receptor, is impaired in activated lymphocytes of patients with relapsing-remitting multiple sclerosis. Using flow cytometric-immunophenotyping, we analyzed the expression of CD95/Fas on peripheral blood CD4+ and CD8+ T lymphocytes (PBL) in 10 MS patients in relapse, and the effect of pulse corticosteroid therapy on the apoptosis of autoreactive lymphocytes. The proportions of CD8+ and CD8+CD95+ T lymphocytes were significantly higher in MS patients in relapse before than after pulse corticosteroid therapy. Conversely, the proportions of CD4+ and CD4+CD95+ T cells were significantly lower before than after therapy, but not significantly different from healthy persons. The different expression of CD95/Fas on peripheral blood CD8+ T lymphocytes in relapsing RRMS and in healthy controls suggests a possible involvement of apoptosis in the pathogenesis of MS. Our results also show that pulse corticosteroid therapy influences the CD95/Fas expression on CD8+ and CD4+ T lymphocytes in patients with RRMS.     

Differential Effects of Fingolimod and Natalizumab on B Cell Repertoires in Multiple Sclerosis Patients

Natalizumab and fingolimod are effective multiple sclerosis (MS) therapies that disrupt lymphocyte migration but have differential effects on B cell maturation and trafficking. We investigated their effects on peripheral blood (PB) and cerebrospinal fluid (CSF) B cell repertoires using next-generation deep sequencing. Paired CSF and PB B cell subsets (naïve, CD27⁺ memory, and CD27⁻IgD⁻ double-negative B cells and plasmablasts) were collected by applying flow cytometry at baseline and after 6 months of treatment and their respective heavy-chain variable region repertoires assessed by Illumina MiSeq. Treatment with fingolimod contracted, whereas natalizumab expanded circulating PB B cells. CSF B cell numbers remained stable following fingolimod treatment but decreased with natalizumab therapy. Clonal overlap between CSF and PB B cells was reduced with natalizumab treatment but remained stable with fingolimod therapy. Lineage analyses of pre- and posttreatment CSF B cell repertoires revealed large, clonally expanded B cell clusters in natalizumab-treated MS patients but no intrathecal clonal expansion following fingolimod therapy. Our findings suggest that natalizumab diminishes the exchange of peripheral and intrathecal B cells without impacting intrathecal clonal expansion. In contrast, fingolimod treatment fails to alter blood–brain barrier B cell exchange but diminishes intrathecal clonal expansion. Sphingosine-1 phosphate receptor inhibition may alter intrathecal B cell biology in MS.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13311-020-00975-7.Key Words: Natalizumab, fingolimod, cerebrospinal fluid, B cell migration, B cell maturation, mass sequencing.     

Different responses to interferon beta‐1b treatment in patients with neuromyelitis optica and multiple sclerosis

Background: Although the benefit of treatment for relapsing–remitting multiple sclerosis (MS) is firmly established, whether interferon beta‐1b (IFNB‐1b) therapy is efficacious for neuromyelitis optica (NMO) has been debated. Methods: We reviewed the responses to IFNB‐1b treatment in 18 patients with relapsing NMO and compared the results with those from 38 patients with relapsing–remitting MS. We compared clinical characteristics, the annualized relapse rate (ARR) and the probability of being relapse free before and after IFNB‐1b treatment in patients with NMO and MS. Results: The proportion of patients with more than 50% increase in the ARR after IFNB‐1b treatment was much higher in NMO than in MS (P = 0.046). ARR was significantly lower in patients with MS after IFNB‐1b administration than before (P = 0.015), but not in NMO. Kaplan–Meier and log‐rank statistical analyses revealed that relapse‐free rates were lower in NMO than MS after IFNB‐1b treatment (P = 0.032). The analyses also showed lower relapse‐free rates during the pre‐IFNB‐1b treatment period than the post‐IFNB‐1b treatment period in MS (P < 0.001), but not in NMO. Conclusion: IFNB‐1b treatment does not appear to be effective for preventing relapse in NMO likely because of differences between the immune‐pathogenesis of NMO and MS.     

B‐cell Therapy for Multiple Sclerosis: Entering an era

Monoclonal antibodies that target CD20 expressing B cells represent an important new treatment option for patients with multiple sclerosis (MS). B‐cell‐depleting therapy is highly effective against relapsing forms of the disease and is also the first treatment approach proven to protect against disability worsening in primary progressive MS. Moreover, evolving clinical experience with B‐cell therapy, combined with a more sophisticated understanding of humoral immunity in preclinical models and in patients with MS, has led to major progress in deciphering the immune pathogenesis of MS. Here, we review the nuanced roles of B cells in MS autoimmunity, the clinical data supporting use of ocrelizumab and other anti‐CD20 therapies in the treatment of MS, as well as safety and practical considerations for prescribing. Last, we summarize remaining unanswered questions regarding the proper role of anti‐CD20 therapy in MS, its limitations, and the future landscape of B‐cell‐based approaches to treatment. Ann Neurol 2018;83:13–26     

视神经脊髓炎患者血清及脑脊液中B淋巴细胞活化因子的表达水平与临床意义

目的 探讨视神经脊髓炎患者血清及脑脊液中B淋巴细胞活化因子的表达水平及其临床意义。方法 选取2011年1月-2015年1月本院收治的视神经脊髓炎(NMO)患者50例及多发性硬化(MS)患者50例,将其分别作为NMO组与MS组,另选取同期于本院进行体检的非炎性神经系统疾病患者50例作为对照组,对3组血清及脑脊液中的B淋巴细胞活化因子(BAFF)水平进行检测。结果 与对照组比较,NMO组与MS组血清中BAFF水平均无明显变化(P>0.05),而NMO组与MS组脑脊液中BAFF水平均明显升高(P<0.05); 与MS组比较,NMO组脑脊液中BAFF水平明显升高(P<0.05)。NMO组与MS组脑脊液中BAFF水平与EDSS评分呈正相关,即脑脊液中BAFF水平随EDSS评分升高而升高(r=0.887,0.885,P<0.01)。结论 视神经脊髓炎患者脑脊液中的B淋巴细胞活化因子水平较高,可能是诊断视神经脊髓炎的重要标志物,对疾病严重程度的判定具有重要的临床意义。     

The CD28 related molecule ICOS: T cell modulation in the presence and absence of B7.1/2 and regulational expression in multiple sclerosis

Costimulatory signals play a key role in regulating T cell activation and are believed to have decisive influence in the inciting and perpetuating cellular effector mechanisms in autoimmune diseases such as multiple sclerosis (MS). Inducible costimulator protein (ICOS), a recently identified member of the CD28-family, presumably affects the differentiation of Th1/Th2 cells after primary activation and modulates the immune response of effector/memory T cells.

This study examines the expression and functional role of ICOS costimulation in healthy donors and patients with MS. After nonspecific or antigen-specific stimulation, ICOS is preferentially expressed on CD4 Th2-T cells. ICOS-costimulation affects the production of Th1 and Th2 cytokines both in the absence and presence of B7/CD28 costimulation, thus suggesting that ICOS costimulation can modulate cytokine secretion also in a CD28-independent manner. Levels of constitutive and inducible ICOS expression on human T cell subsets from peripheral blood were quantified in healthy donors and patients with MS. Constitutive expression of ICOS on T cells varies between 0.1% and 42.3%. There were no significant differences between both groups in the baseline expression or inducibility of ICOS on CD4 or CD8 T cells. ICOS expression could be demonstrated on CSF T lymphocytes in patients with acute MS relapses but was not elevated compared with peripheral blood.

In essence we show that ICOS is upregulated on human T cells after stimulation and can modulate both Th1 and Th2 cytokine production in the absence and presence of B7-costimulation. In MS patients we demonstrate the functionality of the ICOS costimulatory pathway. Potential implications of ICOSL/ICOS interactions for MS immunopathogenesis are discussed.     

Bystander modulation of chemokine receptor expression on peripheral blood T lymphocytes mediated by glatiramer therapy

BACKGROUND: Glatiramer acetate therapy is thought to be effective for multiple sclerosis (MS) by promoting T(H)2 cytokine deviation, possibly in the brain, but the exact mechanism and site of action are incompletely understood. Determining the site of action and effect of glatiramer on cell trafficking is of major importance in designing rational combination therapy clinical trials. OBJECTIVE: To determine whether glatiramer therapy will also act in the peripheral blood through bystander modulation of chemokine receptor (CKR) expression and cytokine production on T lymphocytes. DESIGN: Before-and-after trial. SETTING: A university MS specialty center. PATIENTS: Ten patients with relapsing-remitting MS. INTERVENTIONS: Treatment with glatiramer for 12 months and serial phlebotomy. MAIN OUTCOME MEASURES: Cytokine production, CKR expression, and cell migration. RESULTS: The glatiramer-reactive T cells were T(H)2 cytokine biased, consistent with previous studies. We found a significant reduction in the expression of the T(H)1 inflammation associated with the CKRs CXCR3, CXCR6, and CCR5 on glatiramer- and myelin-reactive T cells generated from patients with MS receiving glatiramer therapy vs baseline. Conversely, expression of the lymph node-homing CKR, CCR7, was markedly enhanced on the glatiramer-reactive T cells derived from patients with MS undergoing glatiramer therapy. There was a reduction in the percentage of CD4+ glatiramer-reactive T cells and an increase in the number of CD8+ glatiramer-reactive T cells. CONCLUSIONS: Glatiramer may suppress autoreactive CD4+ effector memory T cells and enhance CD8+ regulatory responses, and bystander modulation of CKRs may occur in the periphery.     

Peripheral blood B and T-lymphocyte populations in patients with multiple sclerosis. Relationship with clinical activity of the disease and chronic immunosuppressive treatment

During a period of 30 months, we studied the proportions of B and T cells, and of T cell subpopulations, in 924 blood samples from 213 MS patients. The disease was clinically stable in 88 patients (271 samples), relapsing progressive in 50 (349 samples), slowly progressive in 71 (262 samples) and in acute, selfremitting relapses for 31 patients (42 samples). By comparison with controls, untreated MS patients displayed a slightly higher percentage of B-cells (p less than 0.05) and a striking decrease of the mean percentage of CD8 + cells (p less than 0.001). Within the MS group, patients with an active disease presented a more marked decrease of the number of CD8 + cells and an increase of the CD4/CD8 ratio (p less than 0.01). However, 13 out of the 88 clinically stable patients had persistently high CD4/CD8 ratios, whereas such a high ratio was observed only in 60% of samples collected during an acute relapse. Eighty patients with a progressive form of the disease were chronically treated by immunosuppressive drugs, usually cyclophosphamide (N = 69). This treatment induced within one year a marked decrease of the absolute number of B and CD4 + cells, and a return to normal values of the CD4/CD8 ratio.     

Role of B Cells in Multiple Sclerosis and Related Disorders

The success of clinical trials of selective B‐cell depletion in patients with relapsing multiple sclerosis (MS) and primary progressive MS has led to a conceptual shift in the understanding of MS pathogenesis, away from the classical model in which T cells were the sole central actors and toward a more complex paradigm with B cells having an essential role in both the inflammatory and neurodegenerative components of the disease process. The role of B cells in MS was selected as the topic of the 27th Annual Meeting of the European Charcot Foundation. Results of the meeting are presented in this concise review, which recaps current concepts underlying the biology and therapeutic rationale behind B‐cell–directed therapeutics in MS, and proposes strategies to optimize the use of existing anti–B‐cell treatments and provide future directions for research in this area. ANN NEUROL 2021;89:13–23     

Lymphocyte subsets in relapsing-remitting Multiple Sclerosis: A longitudinal study of B lymphocytes and T lymphocytes

Abstract

Changes in lymphocyte subset populations may provide dues to the dysimmune mechanisms involved in relapsing remitting multiple sclerosis (RRMS). The lymphocyte subgroup CD4+CD45RA+, thought to be responsible for the induction of suppression is decreased in some patients with MS compared to controls. A possible role for another lymphocyte subset, CD19+CD5+ lymphocytes; has been proposed in autoimmune diseases and multiple sclerosis (MS). To expand this we studied CD4+CD45RA + (T) lymphocytes and CD19+CD5+ (B) lymphocytes in nine patients with relapsing-remitting MS (RRMS) and nine controls. The patients were examined monthly for an average of ten months and nine relapses were observed in seven patients. One patient underwent monthly gadolinium enhanced magnetic resonance imaging (MRI). Normal percentages CD4+CD45RA+ lymphocytes were found in patients with RRMS. No significant abnormalities in the CD19+CD5+ lymphocyte subpopulation were noted, although a tendency for higher percentages of this subset (approaching statistical significance, P = 0.056) was detected. [Neurol Res 1994; 16: 385-388]     

Rituximab reduces B cells and T cells in cerebrospinal fluid of multiple sclerosis patients

Effects of B cell depletion by rituximab, a monoclonal antibody to CD20, were studied in patients with relapsing MS that had not responded optimally to standard immunomodulatory therapies. Flow cytometry demonstrated reduced cerebrospinal fluid (CSF) B cells and T cells in most patients at 6 months post-treatment. ELISAs demonstrated modest reductions in serum antibodies to myelin oligodendrocyte glycoprotein and myelin basic protein in some subjects. Beta-interferon neutralizing antibodies were reduced in three subjects, but developed anew after treatment in three others, suggesting caution in considering rituximab as a means to eliminate NABs. In summary, rituximab depleted B cells from CSF at 24 weeks after initial treatment, and this B cell depletion was associated with a reduction in CSF T cells as well.     

B cell activation in multiple sclerosis

A microtechnique was established for the study of the limited numbers of cells available in CSF. The method allowed for the determination of the number of immunoglobulin-secreting cells (IgSC) as well as the quantitation of immunoglobulin or specific antibody secreted into the culture medium. Dose-response curves and kinetic profiles for the IgSC responses induced by pokeweed mitogen (PWM), a polyclonal B cell activator, were similar for CSF cells (CSFC) and peripheral blood mononuclear cells (PBMC). When equal numbers of unstimulated CSFC and PBMC from patients with multiple sclerosis (MS) were cultured, both the number of IgSC and the amount of secreted IgG were significantly greater in CSFC cultures. The addition of PWM resulted in the differentiation of B cells among both CSFC and PBMC, as shown by an increase of both the number of IgSC and the amount of secreted IgG. Results with cultures of unstimulated cell suspensions from MS patients suggested that CSF cells from these patients may be activated in vivo. The addition of mitomycin-C treated autologous peripheral blood mononuclear cells (PBMCM) to cultures of small numbers of CSFC or PBMC resulted in an augmentation of the number of IgSC in both, whether or not they were stimulated with PWM, and also in an increased secretion of IgG into the culture supernatants. This culture system should prove useful in functional studies when limited numbers of cells are available.