以BAFF/APRIL为靶点药物治疗系统性红斑狼疮临床研究进展

系统性红斑狼疮(SLE)是一种以致病性自身抗体和免疫复合物形成并介导器官、组织损伤的自身免疫性疾病,近年来不少国内外学者发现B淋巴细胞在SLE的发病中扮演了重要的角色,本文主要对以BAFF/APRIL为靶点的药物治疗SLE的临床试验进展进行综述。     

原发性胆汁性肝硬化患者外周血APRIL基因表达水平初探

目的 建立检测人增殖诱导配体（APRIL）mRNA的实时荧光定量PCR方法,探讨外周血单个核细胞APRIL mRNA表达水平与原发性胆汁性肝硬化（PBC）的相关性。方法 采用实时荧光定量PCR法检测30例正常人和40例PBC患者外周血单个核细胞（PBMC）APRIL基因的相对表达量,以Ct值比较法计算APRIL基因相对表达水平。结果 PBC患者外周血单个核细胞APRIL mRNA的△Ct值为9．3±2.0,与正常对照组比较．差异显著（P〈0．05）。采用2^-△△Ct法进行数据分析后,PBC组APRIL mRNA相对表达量比正常对照组高3．5倍。PBC患者中抗核抗体（ANA）阳性占80％,其中荧光模式为核膜型19例。其他型13例（着丝点型10例,混合型3例）,其APRIL基因相对表达量比正常对照组高6.5和1．7倍。结论 PBC患者外周血单个核细胞APRIL mRNA表达水平显著升高,且与ANA荧光模式相关。     

糖皮质激素和硼替佐米体外干预多发性骨髓瘤细胞BAFF/APRIL mRNA表达的初步探索

本研究观察糖皮质激素和硼替佐米对U266骨髓瘤细胞株和多发性骨髓瘤(MM)患者骨髓单个核细胞(BMMNC)BAFF/APRIL mRNA表达的影响。分离MM患者BMMNC,对U266骨髓瘤细胞株和BMMNC进行药物干预(单用地塞米松100、200μg/ml,甲基强的松龙100、200μg/ml,硼替佐米0.1μg/ml,以及地塞米松或甲基强的松龙与硼替佐米联用)48小时,收集细胞,进行荧光定量实时PCR检测BAFF/APRIL mRNA表达的水平。采用SPSS 17.0进行统计学分析。结果表明,U266细胞及7例初治的MM患者BMMNC均高表达BAFF/APRIL基因。地塞米松,甲基强的松龙,硼替佐米单独作用于U266细胞或MM患者BMMNC后,BAFF/APRIL基因表达较未干预前降低(p<0.01),其中硼替佐米干预后BAFF/APRIL表达最低(p<0.05)。地塞米松或甲基强的松龙和硼替佐米联用后BAFF/APRIL基因表达较单独干预时低(p<0.01);地塞米松联用硼替佐米时BAFF/APRIL基因表达的抑制强度大于甲基强的松龙和硼替佐米联用的抑制强度(p<0.05)。结论:糖皮质激素和硼替佐米干预后的骨髓瘤细胞BAFF/APRIL基因表达下降,提示糖皮质激素和硼替佐米除了存在已知的糖皮质激素受体和蛋白酶体作用靶点外,可能还存在BAFF/APRIL及其受体这种新的作用靶点。     

胰腺癌CFPAC1细胞增殖诱导配体基因shRNA慢病毒表达载体的构建

目的 构建针对人胰腺癌细胞株CFPAC1增殖诱导配体(a proliferation-inducing ligand,APRIL)基因的shRNA慢病毒表达载体.方法 应用基因工程技术,筛选出针对APRIL基因的RNAi靶序列,与pGCL-GFP载体连接,构建慢病毒表达载体LV-shAPRIL;将连接产物转化到DHSα感受态细胞,经PCR筛选阳性克隆、测序鉴定.再用LV-shAPRIL、pHelper 1.0、pHelper 2.0共转染293T细胞,包装产生慢病毒颗粒.重组慢病毒感染CFPAC1细胞,实时定量PCR和Western blotting检测CFPAC1细胞APRIL mRNA和蛋白的表达.结果 PCR和测序结果与构建的慢病毒载体的预期结果一致,经包装产生的病毒滴度为5×107TU/ml.构建的慢病毒载体感染CFPAC1细胞后第4天、第4周和第8周,APRIL mRNA表达量较空载体慢病毒感染组分别下降了73%、70%和71%;APRIL蛋白表达量分别下降了66%、63%和62%(P＜0.05).而各时间段未感染慢病毒的细胞组与空载体组相比无明显差异(P＞0.05).结论 成功构建了APRIL基因的shRNA慢病毒表达载体LV-shAPRIL.     

Up-regulation of CX3CR1 on tonsillar CD8-positive cells in patients with IgA nephropathy

Although tonsillectomy are used as therapeutic options to prevent chronic renal failure in IgA nephropathy (IgAN) patients, the relationship between IgAN and tonsils is not fully proved by basic research. Recently, circulating CX3CR1-positive cells were reportedly involved in promoting hematuria in patients with IgAN. In this study, we focused on the expression of CX3CR1 in tonsillar mononuclear cells in IgAN patients. Immunohistological analysis revealed greater distribution of CX3CR1-positive cells in the inter-follicular area of tonsils in IgAN patients than in non-IgAN patients. CX3CR1-positive cells were also found in the affected renal glomerulus of IgAN patients. Flow cytometric analysis revealed the expression of CX3CR1 on tonsillar CD8-positive cells to be significantly higher in IgAN patients. CpG-oligodeoxynucleotides enhanced the expression in IgAN patients. The chemotactic response of tonsillar mononuclear cells to fractalkine was significantly higher in IgAN patients. Expression of CX3CR1 on peripheral blood CD8-positive cells in IgAN patients was significantly higher, and decreased after tonsillectomy, along with the disappearance of hematuria. These results suggest that hyper-immune response to microbial DNA enhanced the expression of CX3CR1 on tonsillar CD8-positive cells in IgAN patients, followed by the migration of the cells to renal lesions via blood circulation, resulting in the development of hematuria.     

Deleting the BAFF receptor TACI protects against systemic lupus erythematosus without extensive reduction of B cell numbers

B cell-activating factor of the TNF family (BAFF) is an essential B cell survival factor. However, high levels of BAFF promote systemic lupus erythematosus (SLE) in mice and humans. Belimumab (anti-human BAFF) limits B cell survival and is approved for use in patients with SLE. Surprisingly, the efficacy of rituximab (anti-human CD20) in SLE remains controversial, despite depleting B cells more potently than belimumab. This raises the question of whether B cell depletion is really the mechanism of action of belimumab. In BAFF transgenic mice, SLE development is T cell-independent but relies on innate activation of B cells via TLRs, and TLR expression is modulated by the BAFF receptor TACI. Here, we show that loss of TACI on B cells protected against BAFF-mediated autoimmune manifestations while preserving B cells, suggesting that loss of BAFF signaling through TACI rather than loss of B cells may underpin the effect of belimumab in the clinic. Therefore, B cell-sparing blockade of TACI may offer a more specific and safer therapeutic alternative to broad B cell depletion in SLE.     

Naturally occurring bactericidal antibodies specific for Haemophilus influenzae Lipooligosaccharide are present in healthy adult individuals

Nontypeable Haemophilus influenzae (NTHi), a typical mucosal pathogen largely responsible for respiratory infections and pediatric otitis media, has been increasingly recognized as a significant cause of invasive disease, especially in immunocompromised individuals. Lipooligosaccharide (LOS) is a conserved molecule with an important role in H. influenzae virulence and immune evasion, and it may be considered as a vaccine candidate. However, abilities of H. influenzae LOS to induce protective immune response are poorly understood. The goal of this study was to determine whether antibodies against LOS isolated from H. influenzae strains Eagan, Rd and NTHi 375 are present in the sera of normal individuals. Antigen specific IgG and IgM were studied in sera of 71 and 30 healthy adults, respectively. IgG specific for LOS of all three strains was ubiquitously present in our sample population while IgM specific for Eagan, Rd and NTHi 375 LOS compounds was detected in 37%, 63%, and 40% of samples, respectively. All tested serum samples exhibited bactericidal activity against all three H. influenzae strains; the removal of anti-LOS antibodies from the sera resulted in significant increases in bacterial survival of the corresponding strain. NTHi 375 exhibited the highest serum resistance, whereas the Rd strain was the least resistant. Serum bactericidal activity of anti-LOS antibody was mediated via the classical complement pathway. These findings suggest that in healthy adults, naturally acquired complement-activating anti-LOS antibodies significantly contribute to the overall serum bactericidal activity against both encapsulated and non-encapsulated strains of H. influenzae.     

Raised expression of APRIL in Chinese patients with immune thrombocytopenia and its clinical implications

Background: Immune thrombocytopenia (ITP) is an immune-mediated disorder in which destruction of platelets is accelerated by anti-platelet autoimmune antibodies. B-cell-activating factor (BAFF) and a proliferation-inducing ligand (APRIL), essential factors for B cell survival are elevated in systemic autoimmune diseases and correlated with clinical findings. High expression of BAFF has been shown in patients with ITP, but the status of APRIL in ITP is still unknown.

Objective: To determine the expression of APRIL and it receptors, B-cell maturation antigen (BCMA) and trans-membrane activator and calcium modulator and cyclophilin ligand interactor (TACI), in patients with ITP, and evaluate the correlation between plasma APRIL levels and platelet accounts or other clinical parameters.

Methods: Plasma samples from 57 patients with ITP, and 30 normal healthy subjects were assayed for APRIL plasma concentration by enzyme linked immunosorbent assay. Real-time quantitative polymerase chain reaction was performed to determine the mRNA expression of APRIL and its receptors (BCMA and TACI) in peripheral blood mononuclear cells (PBMNCs) in 25 normal controls and 34 untreated ITP patients with active disease.

Results: The APRIL levels in the plasma samples from patients with ITP were significantly higher than those from healthy controls (p = 0.000). PBMNCs may be a source of the excess APRIL. Treated patients with normal platelet count have relatively normal plasma APRIL (p = 0.599). Plasma APRIL levels in active patients were significantly correlated with platelet counts (r = ? 0.387 and p = 0.024).

Conclusion: APRIL is over expressed in untreated active ITP patients and might be a pathogenic factor of this disorder.     

PS-341对多发性骨髓瘤细胞分泌BAFF与APRIL及迁移能力的影响

目的：为了研究PS-341对多发性骨髓瘤细胞株RPMI8226、KM-3及10例多发性骨髓瘤原代细胞分泌及迁移能力的影响。方法：在体外培养多发性骨髓瘤（MM）细胞,以PS-341进行处理,用RT-PCR方法检测BAFF与APRI及其3个受体BAFF-R、TACI、BCMAL基因的表达,用ELSIA方法检测细胞培养上清中可溶性BAFF与APRIL的浓度变化,以transwell方法检测细胞迁移能力的变化。结果：MM细胞RPMI8226及KM3表达BAFF与APRIL及3个受体BAFF-R、TACI、BCMA,但部分病人不表达BCMA;PS-341可以抑制MM细胞自分泌可溶性BAFF与APRIL;PS-341降低MM细胞迁移能力。结论：PS-341抑制多发性骨髓瘤细胞分泌BAFF与APRIL,并可以抑制多发性骨髓瘤细胞的迁移。