Characterization of the murine interleukin 5 receptor by using a monoclonal antibody

Murine interleukin 5 (IL-5), a lymphokine produced by helper T cells, is involved in the regulation of growth and differentiation of B cells and other hematopoietic cells. The receptor for IL-5 has been identified as two cross-linked complexes on T88-M cells (a murine IL-5-dependent early B cell line). In this study the IL-5 receptor was directly characterized by utilizing an immobilized IL-5 column and a rat monoclonal antibody, designated H7, directed against the IL-5 receptor. H7 completely inhibited specific binding of 35S-labeled IL-5 to T88-M cells, and bound to IL-5-responsive cells, e.g. T88-M, BCL1-B20 (a chronic B-cell leukemia), and MOPC104E (a myeloma), whereas H7 did not bind to IL-5-non-responsive cells, e.g. X5563 (a myeloma), FDC-P1 (an IL-3-dependent line), and MTH (an IL-2-dependent CTLL). H7 could barely bind to T88-M cells in the presence of IL-5, and immunoprecipitated a major band with an Mr of approximately 60 kd from the extract of surface-radioiodinated T88-M cells. The precipitation of this 60 kd molecule was inhibited by the addition of IL-5. Analysis with immobilized IL-5 also revealed that a 60 kd molecule bound specifically to IL-5-coupled beads compared with control beads. Furthermore, no additional molecule with a higher Mr that was recognized by H7 appeared under non-reducing, compared with reducing, conditions. The 60 kd molecule recognized by H7 could be digested with N-glycanase to yield a protein band of approximately 55 kd.(ABSTRACT TRUNCATED AT 250 WORDS)     

不同类型的HBsAg真核表达质粒在EBV永生化B淋巴母细胞中的表达

目的 探讨3种不同类型的HBsAg真核表达质粒在EBV永生化B淋巴母细胞中的表达。方法 用3种不同类型的质粒载体分别构建乙型肝炎表面抗原（HBsAg)真核表达质粒（pCI-S,pMEP4-S,pLXSN-S)；然后用阳离子脂质体介导的转染法分别转染正常人EBV永生化的B淋巴母细胞，经G418或HygromycinB筛选出抗性细胞克隆，用RT-PCR检测抗性细胞总RNA中目的基因在转录水平的表达；用ELISA检测抗性细胞培养上清和细胞裂解液中HB-sAg的含量。结果 3种不同类型HBsAg重组表达质粒转染的EBV永生化B淋巴母细胞，在转录水平上，可检出HB-sAgmRNA的表达；在蛋白水平上，细胞增养上清和细胞裂解液均可检出HBsAg；而以EB病毒表达质粒pMEP4-S表达最高，真核表达质粒pCI-S和逆转录病毒表达质粒pLXSN-S表达HBsAg的量无明显差异。结论 3种不同类型的HBsAg真核表达质粒均可在EBV永生化B淋巴母细胞中稳定表达，EB病毒表达质粒pMEP4-S表达的HBsAg明显高于真核表达质粒pCI-S和逆转录病毒表达质粒pLXSN-S。     

Reversibility of the acute toxic effect of Cyclosporin A on pancreatic B cells of Wistar rats

Summary. This study investigated if and to what extent the acute toxic effect of Cyclosporin A on pancreatic Wistar rat B cells is reversible. After 2 weeks of treatment rats developed marked glucose intolerance accompanied by reduced pancreatic insulin content due to a loss of B cells, diminished islet DNA synthesis and decreased B-cell insulin content. Cyclosporin A had accumulated in the pancreas. Three weeks after withdrawal of Cyclosporin A, pancreatic tissue concentrations of Cyclosporin A were still 100 times larger than in serum. Glucose tolerance, however, had already improved, associated with an increase of B-cell insulin content and apparent islet replication, and the insulin response of isolated islets was reduced. Five weeks after the withdrawal of Cyclosporin A, glucose tolerance was normal, but pancreatic insulin content and relative B-cell volume were still diminished in comparison to vehicle-treated controls. Eight weeks after withdrawal, the morphometric parameters had also been normalized. The results suggest that the loss of pancreatic B cells is caused by a toxic destruction, possibly combined with an apparent decrease of replicatory activity. The acute toxic effects of Cyclosporin A in pancreatic B cells are stepwise reversible.     

黄芪桂枝五物汤加减对糖尿病大鼠坐骨神经细胞凋亡相关Bax和Caspase-12的影响

目的 研究黄芪桂枝五物汤加减对糖尿病大鼠坐骨神经细胞凋亡相关B细胞淋巴瘤-2相关X蛋白（Bax）和胱天蛋白酶-12（Caspase-12）蛋白与mRNA表达的影响,以探究黄芪桂枝五物汤加减治疗糖尿病周围神经病变的作用机制。方法 选用动物实验方法进行研究,将60只雄性SD大鼠通过高糖高脂饲料喂养联合链尿佐菌素（STZ）腹腔注射诱导成糖尿病大鼠动物模型,连续3 d随机血糖≥16.7 mmol·L^-1者为糖尿病大鼠造模成功,将48只造模成功的糖尿病大鼠随机分为模型组、α-硫辛酸组（0.026 8 g·kg^-1·d^-1）、中药高、低剂量组（2.5、1.25 g·kg^-1·d^-1）,每组各12只,并设正常组10只。监测大鼠体质量和随机血糖水平;干预16周末通过Key point肌电采集系统检测大鼠坐骨神经传导速度;分别通过蛋白免疫印迹法（Western blot）和实时荧光定量聚合酶链式反应（Real-time PCR）检测大鼠坐骨神经中Bax和Caspase-12蛋白与mRNA的表达。结果 与正常组比较,模型组大鼠体质量显著下降（P<0.01）,随机血糖水平显著升高（P<0.01）;干预16周,与模型组比较,中药高剂量组大鼠体质量明显升高（P<0.05）,其他给药组体质量变化差异无统计学意义;各给药组随机血糖水平均显著降低（P<0.01）。与正常组比较,干预16周,模型组大鼠运动和感觉神经传导速度显著降低（P<0.01）;与模型组比较,各给药组大鼠运动和感觉神经传导速度均明显升高（P<0.05,P<0.01）。与正常组比较,模型组大鼠坐骨神经Bax和Caspase-12蛋白表达显著升高（P<0.01）;与模型组比较,各给药组大鼠坐骨神经Bax和Caspase-12蛋白表达均显著降低（P<0.01）。与正常组比较,模型组大鼠坐骨神经Bax和Caspase-12 mRNA表达显著升高（P<0.01）;与模型组比较,α-硫辛酸组、中药高剂量组大鼠坐骨神经Bax mRNA表达明显降低（P<0.05,P<0.01）,中药低剂量组坐骨神经Bax mRNA表达降低有下降趋势;各给药组大鼠坐骨神经Caspase-12 mRNA表达显著降低（P<0.01）。结论 黄芪桂枝五物汤加减可能通过抑制坐骨神经细胞凋亡来改善和修复糖尿病大鼠坐骨神经损伤。     

8例B细胞淋巴瘤的T细胞基因CD4 V4突变及其相关蛋白的表达

【目的】检测B细胞淋巴瘤组织中T细胞的CD4V4基因突变情况及其相应病例的Fas/FasL、CD4、bcl 2和CyclinD1蛋白表达特征。【方法】PCR SSCP技术筛选检测 5 6例B细胞淋巴瘤CD4分子的V4外显子突变状况。用免疫组化方法检测有突变的B细胞淋巴瘤组织中L2 6 ,UCHL1,CD3,Fas ,FasL ,bcl 2和CyclinD1蛋白表达情况。【结果】 8例 / 5 6例(14 2 % )T细胞CD4V4外显子有变异。其中小淋巴细胞性淋巴瘤 (smalllymphocytelymphoma,SLL)和淋巴母细胞性淋巴瘤(lymphoblasticlymphoma ,LBL)的Fas,FasL和CD4蛋白均为弱或无表达 ;滤泡性淋巴瘤 (follicularlymphoma ,FL) 3项均强表达 ;3例弥漫性大B细胞淋巴瘤 (diffuselargeBcelllymphoma ,DLBL)和 1例套细胞淋巴瘤 (mantlecelllymphoma ,MCL)Fas和FasL强表达 ,CD4无或弱表达。Fas和FasL双强表达的 4例 ,均有bcl 2和 /或CyclinD1过表达。【结论】B细胞淋巴瘤中CD4V4基因有突变 ,并提示这种突变与细胞死亡和细胞周期调控异常有关。     

Antibody and memory B cell responses to the dengue virus NS1 antigen in individuals with varying severity of past infection

To further understand the role of NS1-specific antibodies (Abs) in disease pathogenesis, we compared neutralizing antibody levels (Nabs), NS1-Ab levels, IgG antibody subclass profiles and NS1-specific memory B-cell responses (Bmems) in individuals, with varying severity of past dengue. Nabs (Neut50 titres) were assessed using the Foci Reduction Neutralization Test (FRNT) and in-house ELISAs were used to assess NS1-Abs and NS1-Ab subclasses for all four DENV serotypes in individuals with past DF (n = 22), those with past DHF (n = 14) and seronegative (SN) individuals (n = 7). B-cell ELISpot assays were used to assess NS1-specific Bmem responses. 15/22 (68.18%) individuals with past DF and 9/14 (64.29%) individuals with past DHF had heterotypic infections. Neut50 titres were found to be significantly higher for DENV1 than DENV2 (p = 0.0006) and DENV4 (p = 0.0127), in those with past DHF, whereas there was no significant difference seen in titres for different DENV serotypes in those with past DF. Overall NS1-Ab to all serotypes and NS1-specific IgG1 responses for DENV1, 2 and 4 serotypes were significantly higher in those with past DHF than individuals with past DF. Those with past DHF also had higher IgG1 than IgG3 for DENV1 and DENV3, whereas no differences were seen in those with past DF. Over 50% of those with past DF or DHF had NS1-specific Bmem responses to >2 DENV serotypes. There was no difference in the frequency of Bmem responses to any of the DENV serotypes between individuals with past DF and DHF. Although the frequency of Bmem responses to DENV1 correlated with DENV1-specific NS1-Abs levels (Spearman r = 0.35, p = 0.02), there was no correlation with other DENV serotypes. We found that those with past DF had broadly cross-reactive Nabs, while those with past DHF had higher NS1-Ab responses possibly with a different functionality profile than those with past DF. Therefore, it would be important to further evaluate the functionality of NS1-specific antibody and Bmem responses to find out the type of antibody repertoire that is associated with protection against severe disease.     

Angiotropic large B-cell lymphoma with clinical features resembling subacute combined degeneration of the cord

Angiotropic large cell lymphoma is a rare neoplastic disorder associated with a high mortality. The hallmark of the disease is lymphoid proliferation confined to the intravascular compartment without local tissue or vessel wall infiltration [1]. This feature is so striking that the disease was originally thought to arise from endothelial tissue and early cases were described as malignant angioendotheliomatosis. However, application of immunohistochemical methods for detection of lymphoid markers such as the CD45 and CD20 cell surface markers has confirmed its lymphoid origin, usually of B-cell lineage [2]. Clinical manifestations of the disease are protean and are due to multifocal medium and small vessel occlusion by tumour cells [3]. Characteristic sites of involvement are skin and central nervous system and although an ante-mortem diagnosis can be made from a biopsy specimen, it is often unsuspected [4]. We present a case of angiotropic large B-cell lymphoma in a 74-year-old man who presented with urinary symptoms and had a neurological picture resembling subacute combined degeneration of the cord.     

CD73 and Adhesion of B-Cells to Follicular Dendritic Cells

CD73, otherwise known as ecto-5'-nucleotidase, is a lymphocyte maturation marker which is involved in intracellular signalling, lymphocyte proliferation and activation. In addition, we have demonstrated that CD73 is involved in mediating lymphocyte binding to in vitro cultured endothelial cells and in controlling adhesion between freshly isolated germinal center B-cells and follicular dendritic cells (FDC). In secondary lymphoid tissues, CD73 is expressed on FDC in the light zone of the germinal center as well as on small, resting mantle zone B-cells but not on B-cells within germinal centers. In this review article, the potential role of CD73 in controlling B-cell-FDC interactions and B-cell maturation will be discussed.     

Treating chronic lymphocytic leukemia with thalidomide and lenalidomide

Introduction: Chronic lymphocytic leukemia (CLL) is biologically, as well as clinically, highly heterogeneous. In CLL patients, immunosuppression is a consequence of the disease, which plays a key role in effecting the quality of life and overall survival. Treatment modalities should ideally not only reduce tumor burden, but also augment immune function in CLL patients.

Areas covered: The current review summarizes biological and clinical data on thalidomide and lenalidomide in CLL.

Expert opinion: Immunomodulatory drugs such as thalidomide and lenalidomide show both antitumor activity and immunostimulation. Three main mechanisms of action seem to play a role in cancer, including i) anti-angiogenic, ii) immunomodulatory and iii) tumoricidal effects. The exact contributions of these effects seem to be unique for different diseases. The two representatives of this family of drugs studied in CLL include thalidomide and its analog lenalidomide. These drugs proved to be effective as single agents and in the combination setting in CLL. Toxicities have been identified but largely controlled by a low starting dose, with gradual dose escalation.