Identification of DNA-reactive B cells in patients with systemic lupus erythematosus

Autoreactive B cells play a central role in systemic lupus erythematosus (SLE). Characterization of DNA-reactive B cells in the blood of lupus patients has been limited by the low frequency of the population. Using a tetrameric configuration of a peptide mimetope of DNA, we identified peptide-reactive B cells in peripheral blood. Antibodies derived from these B cells bound to peptide and were largely cross-reactive to dsDNA. This methodology enables us to track the development of autoreactive B cells, which recognize peptide and dsDNA, in individual patients with SLE and permits the isolation of autoreactive B cells for further characterization.     

Targeting iNKT cells for the treatment of sickle cell disease

Sickle cell disease (SCD) causes widely disseminated vaso-occlusive episodes. Building on evidence implicating invariant NKT (iNKT) cells in the pathogenesis of ischemia/reperfusion injury, recent studies demonstrate that blockade of iNKT cell activation in mice with SCD reduces pulmonary inflammation and injury. In patients with SCD, iNKT cells in blood are increased in absolute number and activated in comparison to healthy controls. iNKT cell activation is reduced by agonists of adenosine 2A receptors (A(2A)Rs) such as the clinically approved coronary vasodilator, regadenoson. An ongoing multi-center, dose-finding and safety trial of infused regadenoson, has been initiated and is providing preliminary data about its safety and efficacy to treat SCD. Very high accumulation of adenosine may have deleterious effects in SCD through activation of adenosine 2B receptors that are insensitive to regadenoson. Future possible therapeutic approaches for treating SCD include selective A(2B)R antagonists and antibodies that deplete iNKT cells.     

B cell elimination in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disorder with a worldwide distribution, potentially life-threatening with considerable morbidity. The elimination of pathogenic B cells has emerged as a rational therapeutic option. Many open label studies have reported encouraging results in which clinical and serological remission have invariably been described, often enabling the reduction of steroid and immunosuppressive treatment. However, the results from randomized controlled studies have been disappointing and several questions remain to be answered. In this review we will focus on results of B cell direct depletion in the treatment of patients with systemic lupus erythematosus.     

Abnormalities of B cell subsets in patients with systemic lupus erythematosus

The prototypic autoimmune disease, SLE, is known to be associated with polyclonal B cell hyperreactivity. Developing an understanding of the complex nature of human B cell differentiation, largely through the application of multiparameter flow cytometry to an analysis of circulating B cells has permitted an assessment of whether specific stages of B cell maturation are affected by the tendency for polyclonal B cell activation. Moreover, the analysis of perturbations of the specific stages of B cell maturation has generated new information on whether abnormalities in B cell differentiation are primarily involved in autoimmune disease immunopathology or, rather, are secondary to the inflammatory environment characteristic of subjects with this autoimmune disease. Multivariant analysis has begun to document abnormalities in B cell maturation that are primarily associated with lupus, or, alternatively related to disease duration, disease activity and concomitant medication. Together, these analyses have provided new insights on the role of B cell over-reactivity in SLE.     

B cells and atherosclerosis in systemic lupus erythematosus

Introduction: Cardiovascular (CV) events, as a result of accelerated atherosclerosis, are an important cause of mortality in patients with Systemic lupus erythematosus (SLE). The etiology of SLE is multifactorial and still unclear; among other potential culprits, excessive B cell activation seems to play a crucial role. Accumulating evidence supports a contributory role of B cells in the pathogenesis of atherosclerosis as well.

Areas covered: This article focuses on the contribution of both B cells and autoantibodies in the pathogenesis of atherosclerosis in both general and lupus populations. Review of the published literature on experimental models has also been performed.

Expert opinion: Distinct B cell subsets seem to exhibit separate effects on the progression of atherosclerosis, with B2 B cells displaying a mainly atherogenic phenotype, while B1 B cells are mostly viewed as atheroprotective. Selective B2 inhibition by anti-B cell therapies seems a promising therapeutic strategy against atherosclerosis development in the setting of lupus.     

Quantitation of autoantibody-secreting B cells in systemic lupus erythematosus

An ELISA spot assay was used to quantitate the number of autoantibody-secreting B cells in the peripheral blood of patients with systemic lupus erythematosus. Patients with active disease had 20 fold more anti-DNA, 4 fold more anti-actin and 3 fold more anti-myosin secreting lymphocytes than controls but normal numbers of anti-cardiolipin and anti-transferrin secreting B cells. 60% of SLE patients had increased numbers of B cells reactive with multiple autoantigens. These data suggest that B cell activation in SLE may be influenced by both antigen-specific and antigen-independent factors.     

Abnormal production of B cell growth factor in patients with systemic lupus erythematosus.

In order to clarify the role of B cell growth factor (BCGF) in the pathogenesis of systemic lupus erythematosus (SLE), BCGF production by peripheral blood mononuclear cells (PBMC) and T cells was studied using a new bioassay for BCGF activity. For this purpose, we established an Epstein-Barr (EB) virus-transformed B cell line KS-3.F10 that proliferates only in response to two B cell-specific BCGF, low-mol. wt BCGF (LMW-BCGF) and high-mol. wt BCGF (HMW-BCGF). PBMC from active SLE patients produced less BCGF when stimulated with phytohaemagglutinin (PHA) compared with controls. The decreased BCGF production by PHA-stimulated PBMC from active SLE reverted to control values when SLE became inactive. However, PHA-stimulated T cells from active SLE patients produced more BCGF compared with controls, whereas those from inactive SLE showed normal BCGF production. Spontaneous BCGF production by T cells was not observed in active SLE patients. These findings suggest that decreased BCGF production by SLE PBMC is due to excessive BCGF consumption by B cells in vitro and that SLE T cells produce large amounts of BCGF with appropriate immune stimuli in vivo to promote polyclonal B cell activation.     

Regulatory T cells in systemic lupus erythematosus

Systemic lupus erythematosus (SLE), an autoimmune disease, develops when immunologic self‐tolerance fails. Treg cells are a subset of CD4⁺ T cells that maintain self‐tolerance by suppressing autoreactive lymphocytes. Defects in Treg cells are therefore considered to be an aspect of SLE pathogenesis. Nevertheless, reports on the numbers and function of Treg cells in SLE are contradictory and the definitive role of Treg cells in SLE remains unclear. In this review, we summarize findings from murine models and ex vivo experiments, which provide insights into the mechanisms that result in the breakdown of tolerance. We also include recent findings about Treg‐cell subsets and their markers in human SLE. The identification of unique markers to identify bona fide Treg cells, as well as therapies to reconstitute the balance between Treg cells and autoreactive T cells in SLE, are the future challenges for SLE research.     

定量蛋白质组学技术构建系统性红斑狼疮疾病的蛋白质组差异表达图谱

目的: 应用定量蛋白质组学技术对系统性红斑狼疮(SLE)病人外周血单个核细胞中的"全组"蛋白进行鉴定和定量分析,获得SLE的蛋白质组差异表达图谱。方法: 利用基于四重相对和绝对定量的等量异位标签结合多维液相色谱-串联质谱分析SLE稳定期和活动期病人以及类风湿关节炎病人和健康人的外周血单个核细胞总蛋白,用肽质量指纹谱经数据库检索鉴定蛋白质,并比较这些蛋白的表达差异。结果: 共鉴定了400多个蛋白质。其中,与健康对照组相比,SLE稳定组和SLE活动组共发现2倍以上表达差异的蛋白质44个,上调的9个,下调的35个;与类风湿关节炎疾病组相比,SLE稳定组和SLE活动组2倍以上表达差异的蛋白共有52个,上调的19个,下调的33个;SLE活动组与SLE稳定组相比,表达上调和下调的蛋白分别为17个和13个。结论: 定量蛋白质组学技术可有效地用于人外周血单个核细胞蛋白鉴定和相对定量;采用该技术获得了SLE病人外周血单个核细胞的蛋白质组差异表达图谱;深入研究这些蛋白的分子机制将有助于进一步阐明SLE的发病机制,为SLE的诊断和治疗提供新途径。     

脐带间充质干细胞与系统性红斑狼疮

系统性红斑狼疮（SLE）是一种以免疫细胞活化和自身抗体产生为特征的自身免疫病。间充质干细胞（MSC）是属于中胚层的一类多能干细胞,不仅具有多向分化潜能,还有多种免疫调节作用。许多研究表明MSC对可以通过调节免疫细胞（上调Foxp3’T细胞水平、下调Th17细胞水平、抑制浆细胞的成熟等）的表达以及细胞因子（IL-10、TGF—β、TNF—α等）的分泌干预抑制SLE,并且免疫原性较低。尤其脐带MSC,因为其独特优势,目前已经成为干细胞干预治疗SLE的研究热点。     

调节性B细胞的特性及在疾病中发挥的作用

B淋巴细胞通过分泌抗体和抗原递呈等在机体免疫应答中一直发挥着重要作用.近来研究发现了一群具有调节功能的B淋巴细胞亚群——调节性B细胞(Breg).根据Breg分泌细胞因子不同,Breg分为3种不同亚型:分泌IL-10的B10,分泌TGF-β的Br3和表达FoxP3的FoxP3+ Breg.Breg在多种自身免疫性疾病、寄生虫感染和肿瘤等疾病中发挥着重要的免疫抑制作用.研究Breg的分类、起源与分化发育、分化发育相关的信号通路、表型特征及其在不同种类疾病中的作用可以全面深入地了解Breg的特征和相互作用的机制,因而具有重要意义.     

Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25^+/highCD127^Ø/lowFoxP3⁺, and effector T cells were defined as CD25⁺CD127⁺FoxP3^Ø. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4⁺TREG and CD28⁺TREG cells and an increased frequency of CD40L⁺TREG cells. There was a decrease in the TREG/effector-T ratio for GITR⁺, HLA-DR⁺, OX40⁺, and CD45RO⁺ cells, and an increased ratio of TREG/effector-T CD40L⁺ cells in patients with SLE. In addition, CD40L⁺TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease.     

CD5+ B cells from individuals with systemic lupus erythematosus express granzyme B

Recently, we reported that IL‐21 induces granzyme B (GzmB) and GzmB‐dependent apoptosis in malignant CD5⁺ B cells from patients with chronic lymphocytic leukemia. Several autoimmune diseases (AD) are associated with enhanced frequencies of CD5⁺ B cells. Since AD are also associated with elevated IL‐21 and GzmB levels, we postulated a link between CD5⁺ B cells, IL‐21 and GzmB. Here, we demonstrate that IL‐21 and GzmB serum levels are highly correlated in subjects with systemic lupus erythematosus (SLE) and that freshly isolated CD5⁺ SLE B cells constitutively express GzmB. IL‐21 directly induced GzmB expression and secretion by CD5⁺ B cells from several AD and from cord blood in vitro, and the simultaneous presence of BCR stimulation strongly enhanced this process. Furthermore, IL‐21 suppressed both viability and expansion of CD5⁺ B cells from SLE individuals. In summary, our study may explain the elevated levels of IL‐21 and GzmB in SLE and other AD. Moreover, our data suggest that IL‐21 may have disease‐modifying characteristics by inducing GzmB in CD5⁺ B cells and by suppressing their expansion. Our results provide the rationale for further evaluation of the therapeutic potential of IL‐21 in certain AD such as SLE.     

TF-1细胞凋亡相关基因19在系统性红斑狼疮发病中的作用

目的:探讨TF-1细胞凋亡相关基因19(TFAR19)在系统性红斑狼疮(SLE)发病诱因中的作用及其与SLE病情的关系。方法:应用倒置相差显微镜、Ladder方法、Western blotting方法、荧光免疫显微镜、ELISA方法检测中波紫外线(UVB)诱导HaCaT细胞凋亡时TFAR19的表达及其与SLE患者病情的关系。结果:在剂量为30mJ/cm²的UVB照射24h后,HaCaT细胞开始凋亡,TFAR19在此过程中有表达,发现活动期SLE患者血清中TFAR19的抗体值高于稳定期和正常对照组的值(P≤0.05)。结论:在UVB诱导角质形成细胞HaCaT凋亡的过程中,有TFAR19的参与并发挥了作用,提示TFAR19可能和SLE的发病和病情有关。     

IL-10 production in B cells is confined to CD154+ cells in patients with systemic lupus erythematosus

The immunological hallmark of SLE is B cell hyperactivity. CD154 (CD40-L) is normally expressed in activated T cells, and plays an important role in T-B interactions. Its expression is increased in SLE T cells. Additionally, its expression on B cells leads to the development of SLE-like disease in a transgenic model. IL-10 is a key cytokine in the disturbed SLE immune system. The aim of this work was to explore the relation between IL-10 and CD154 expression in SLE B cells. We studied 11 SLE patients and 10 healthy volunteers. Mononuclear cells were isolated from peripheral blood and cultured in the presence or absence of Cowan I Strain Staphylococcus (CSS). Surface CD154 and intracytoplasmic IL-10 expression were quantified with flow cytometry. In basal conditions, CD154 expression was not different in patients and controls. B cell stimulation did not cause a significant increase in CD154 expression in control B cells. However, its expression increased 2 times in B cells obtained from SLE patients. IL-10 expression was confined to CD154(+) cells. Our results show that IL-10 production is intimately linked to CD154 expression in B cells, and that the IL-10(+)CD154(+) B cell subset increases abnormally when SLE-derived cells are stimulated with CSS.     

Short-term memory in children with sickle cell disease: Executive versus modality-specific processing deficits

Prior research has identified a number of areas of cognitive deficit among children with sickle cell disease (SCD), including decrements in memory span and working memory. The present study examined short-term memory span and working memory performance among children with SCD (n = 25) and demographically matched comparison children (n = 25) using digit span, spatial span, and the self-ordered pointing test. Children with SCD showed difficulties only for digit span-backward. Additional cognitive ability measures administered indicated auditory processing was an area of deficit related to digit span-backward performance. The study suggests that modality specific deficits are one factor in short-term memory span for children with SCD. The cause of this deficit is unclear, but may involve both central and peripheral components of auditory processing.     

CD4+CXCR3+ T cells and plasmacytoid dendritic cells drive accelerated atherosclerosis associated with systemic lupus erythematosus

Cardiovascular disease due to accelerated atherosclerosis is the leading cause of death in patients with systemic lupus erythematosus (SLE). Noteworthy, accelerated atherosclerosis in SLE patients appears to be independant of classical Framingham risk factors. This suggests that aggravated atherosclerosis in SLE patients may be a result of increased inflammation and altered immune responses. However, the mechanisms that mediate the acceleration of atherosclerosis in SLE remain elusive. Based on experimental data which includes both humans (SLE patients and control subjects) and rodents (ApoE−/− mice), we herein propose a multi-step model in which the immune dysfunction associated with SLE (i.e. high level of IFN-α production by TLR 9-stimulated pDCs) is associated with, first, an increased frequency of circulating pro inflammatory CD4+CXCR3+ T cells; second, an increased production of CXCR3 ligands by endothelial cells; third, an increased recruitment of pro-inflammatory CD4+CXCR3+ T cells into the arterial wall, and fourth, the development of atherosclerosis. In showing how SLE may promote accelerated atherosclerosis, our model also points to hypotheses for potential interventions, such as pDCs-targeted therapy, that might be studied in the future.     

Th17细胞及IL-17与系统性红斑狼疮

系统性红斑狼疮（SLE）是多种因素相互作用引起的自身免疫性疾病,其发病机制复杂。Th17细胞是最近发现的CD4^＋效应T细胞的新亚群。初始T细胞在TGF—B和IL-6的共同作用下分化发育成为Th17细胞,后者可以分泌IL-17、IL-21、IL-22等多种细胞因子。其中IL-17在多种自身免疫疾病（比如类风湿关节炎和Crohn’s病）中起关键作用,但在SLE中的作用尚不清晰。