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。     

BAFF及其特异性受体BAFF—R对多发性骨髓瘤细胞增殖及凋亡的影响研究

目的探讨B淋巴细胞刺激因子（BAFF）及其特异性受体BAFF—R对多发性骨髓瘤（MM）细胞增殖及凋亡的影响。方法采用流式细胞术（FCM）、RT—PCR、WesternBlot、荧光免疫细胞化学技术检测BAFF及其受体BAFF—R的表达与定位;wsT细胞增殖实验及TUNEL法检测BAFF及其受体BAFF—R对MM肿瘤细胞生长、存活与凋亡的影响。结果①MM细胞能够表达BAFF及其特异性受体BAFF—R;②BAFF及其受体BAFF—R定位表达于KM3细胞的浆膜上;③BAFF及其受体BAFF—R促进MM细胞的增殖、存活,抗细胞凋亡。结论BAFF及其受体BAFF—R对于骨髓瘤发生、发展可能起着重要的作用。     

BAFF binding to T cell-expressed BAFF-R costimulates T cell proliferation and alloresponses

Binding of the TNF family member, B cell activating factor (BAFF), to its receptor (BAFF-R, TNFRSF13C) is required for generation and maintenance of mature B cells, but there are no data as to any role for the BAFF/BAFF-R pathway in T cell functions. We report that the binding of BAFF to BAFF-R expressed by a subset of primarily CD4(+) T cells costimulates T cell activation and allo-proliferation in vitro and in vivo, and that mice with a mutation in the BAFF-R, or with a targeted deletion of BAFF, show prolonged cardiac allograft survival as compared to wild-type or transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI)(-/-) controls. Taken together, these data indicate the BAFF/BAFF-R pathway contributes to both T and B cell responses and may be an attractive target for control of acute and chronic allograft rejection.     

Interleukin (IL)‐39 [IL‐23p19/Epstein–Barr virus‐induced 3 (Ebi3)] induces differentiation/expansion of neutrophils in lupus‐prone mice

Interleukin (IL)‐12 family cytokines play critical roles in autoimmune diseases. Our previous study has shown that IL‐23p19 and Epstein–Barr virus‐induced 3 (Ebi3) form a new IL‐12 family heterodimer, IL‐23p19/Ebi3, termed IL‐39, and knock‐down of p19 or Ebi3 reduced diseases by transferred GL7⁺ B cells in lupus‐prone mice. In the present study, we explore further the possible effect of IL‐39 on murine lupus. We found that IL‐39 in vitro and in vivo induces differentiation and/or expansion of neutrophils. GL7⁺ B cells up‐regulated neutrophils by secreting IL‐39, whereas IL‐39‐deficient GL7⁺ B cells lost the capacity to up‐regulate neutrophils in lupus‐prone mice and homozygous CD19^cre (CD19‐deficient) mice. Finally, we found that IL‐39‐induced neutrophils had a positive feedback on IL‐39 expression in activated B cells by secreting B cell activation factor (BAFF). Taken together, our results suggest that IL‐39 induces differentiation and/or expansion of neutrophils in lupus‐prone mice.     

Role of B cells in the pathogenesis of systemic sclerosis

Systemic sclerosis (SSc) is an orphan disease characterized by progressive fibrosis of the skin and internal organs. Aside from vasculopathy and fibrotic processes, its pathogenesis involves an aberrant activation of immune cells, among which B cells seem to play a significant role. Indeed, B cell homeostasis is disturbed during SSc: the memory subset is activated and displays an increased susceptibility to apoptosis, which is responsible for their decreased number. This chronic loss of B cells enhances bone marrow production of the naïve subset that accounts for their increased number in peripheral blood. This permanent activation state can be explained mainly by two mechanisms: a dysregulation of B cell receptor (BCR) signaling, and an overproduction of B cell survival signals, B cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL). These disturbances of B cell homeostasis induce several functional anomalies that participate in the inflammatory and fibrotic events observed during SSc: autoantibody production (some being directly pathogenic); secretion of pro-inflammatory and pro-fibrotic cytokines (interleukin-6); direct cooperation with other SSc-involved cells [fibroblasts, through transforming growth factor-β (TGF-β) signaling, and T cells]. These data justify the evaluation of anti-B cell strategies as therapeutic options for SSc, such as B cell depletion or blockage of B cell survival signaling.     

An increase in B cell apoptosis by interfering BAFF-BAFF-R interaction with small synthetic molecules

B cell-activating factor (BAFF) transmitted signals through binding to specific BAFF receptors (BAFF-R) to regulate B cell survival and development. We used MTT assay to examine the cytotoxicity of chemicals, flow cytometry analysis to measure BAFF–BAFF-R interactions, and western blotting to detect BAFF protein. Here, we established screening method to find specific compounds to interfere with BAFF–BAFF-R interactions in WIL2-NS B lymphoblast cells. According to screening (imidazol-4-ylcarbonyl)guanidine or (oxazol-4-ylcarbonyl)guanidine derivatives, we selected KR32592, KR32673, KR33232, KR33341 and KR33426 as candidates to interfere with BAFF–BAFF-R interaction. No cytotoxicity was detected by KR32592, KR33232, and KR33426 at the concentration of 5 μM, and by KR32673, and KR33341 at the concentration of 0.5 μM. Cell population with BAFF–BAFF-R interactions was reduced by the pre-incubation of chemicals with human BAFF-murine CD8 (BAFF-muCD8). Cell population with BAFF–BAFF-R interactions was also decreased by pre-exposure of WIL2-NS cells to chemicals prior to the incubation with BAFF-muCD8. Chemicals also inhibited LPS-stimulated BAFF production from splenocytes. All these effects of chemicals may contribute to the inhibition of BAFF-mediated anti-apoptosis. These data demonstrate that chemicals interfering with BAFF–BAFF-R interaction may be screened with our experimental condition. It suggests that BAFF–BAFF-R interaction could be a chemical target to develop therapeutics for BAFF-mediated autoimmune diseases.     

Therapeutic approaches to myeloma bone disease: an evolving story

Bone disease is a major morbidity factor in patients with multiple myeloma and significantly affects their overall survival. A complex interplay between malignant plasma cells and other marrow cells results in the generation of a microenvironment capable of enhancing both tumor growth and bone destruction. Bisphosphonates have consistently reduced the incidence of skeletal-related events in patients with multiple myeloma and other osteotropic tumors as well. However, their use is burdened with side-effects, including the risks of osteonecrosis of the jaw and kidney failure, suggesting that they should be discontinued after prolonged administration. New molecular targets of cell cross-talk in myeloma bone marrow are therefore under intensive investigation and new drugs are being explored in preclinical and clinical studies of myeloma bone disease. Compounds targeting osteoclast activation pathways, such as receptor activator of nuclear factor-κB/receptor activator of nuclear factor-κB ligand/osteoprotegerin, B-cell activating factor, mitogen-activated protein kinase and macrophage inflammatory protein-1α/chemokine receptor for macrophage inflammatory protein-1α axes, or soluble agents that improve osteoblast differentiation by modulating specific inhibitors such as Dickkopf-1 and transforming growth factor-β, as well as novel approaches of cytotherapy represent a new generation of promising drugs for the treatment of myeloma bone disease.     

特发性血小板减少性紫癜患者BAFF和APRIL表达及意义

目的研究B细胞激活因子（BAFF）和增生诱导配体（APRIL）在特发性血小板减少性紫癜（ITP）的表达情况及其临床意义。方法应用双抗夹心ELISA方法检测27例ITP患者的血清BAFF和APRIL水平,并进行相关分析。结果①ITP组的血清BAFF和APRIL分别为3．92&#177;1．88μg／ml和（34．12&#177;30．52）μg／ml,均明显高于对照组的2．90&#177;0．52μg／ml和17．97&#177;4．96μg／ml（分别为P〈0．05和P〈0．01）;②ITP组血清BAFF和APRIL水平相关分析为r=0．5019,t=2．9028,P〈0．01;而对照组r=-0．2170,P〉0．05。结论ITP患者的BAFF和APRIL均高表达,可能是ITP发生机制的重要原因之一。     

多发性骨髓瘤患者骨髓中BAFF的含量及B细胞表面BAFF受体表达的研究

本研究旨在分析多发性骨髓瘤(MM)患者骨髓中B细胞活化因子(BAFF)、增殖诱导配体(APRIL)的含量,B细胞、初始B细胞和记忆B细胞表面BAFF受体的表达,以探讨MM骨髓中B细胞的特点。采用流式细胞术检测19例初治MM(初治组)、17例平台期MM(平台期组)、10例对照组骨髓中B细胞(CD19+)、初始B细胞(CD19+IgD+)、记忆B细胞(CD19+CD27+)的表面BAFF受体(BAFF-R、TACI)的表达,ELISA法测定各组骨髓上清中BAFF、APRIL的含量。分析各组结果数据的差异及它们之间的相互关系。结果表明,初治组患者CD19+细胞表面BAFF-R受体表达明显高于平台期组和对照组;初治组患者CD19+IgD+细胞表面BAFF-R受体表达与平台期组无差别,但明显高于对照组;初治组患者CD19+CD27+细胞表面BAFF-R受体表达明显高于平台期组和对照组;各种B细胞表面BAFF-R受体表达在平台期组与对照组之间无差别;TACI受体表达总体水平低,初治组患者与平台期组、对照组比较,CD19+细胞、CD19+IgD+细胞、CD19+CD27+细胞表面TACI受体表达均无明显差异;初治组骨髓上清中BAFF含量明显高于平台期组和对照组,但平台期组与对照组间无明显差异;各组骨髓中APRIL的含量均无明显差异。结论:MM患者骨髓中BAFF含量增高,CD19+细胞、CD19+IgD+细胞和CD19+CD27+细胞表面BAFF受体的表达均增加,这可能有助于促进B细胞的增殖,因而可能与MM发病机制有关。