两种脓毒症模型小鼠血清白细胞介素-6与其早期生存率的关系

目的探讨盲肠结扎穿孔( CLP)、腹腔持续置管引流( CASP)脓毒症模型小鼠血清白细胞介素-6(IL-6)与其早期生存率的关系。方法将60只雄性BALB/c小鼠编号,采用数字表法随机分为3组,即假手术组( Sham组)、CLP组、CASP组,各20只。 CLP组小鼠麻醉后,于中下腹正中线做纵行切口,充分暴露并结扎盲肠,用18 G注射器针头在结扎部位远端穿孔并来回贯穿2次,将少量肠内容物挤出,回纳盲肠,缝合腹壁切口。 CASP组术前准备、开腹方式同CLP模型,暴露小鼠升结肠系膜,在其对侧处插入静脉导管,退出针芯,荷包缝合并固定、剪断静脉导管,将游离端放置于腹腔内。用棉签挤压肠管,使少量肠内容物从导管口溢出,以确认导管通畅。 Sham组术前准备、开腹、术后处理同CLP组,不行盲肠结扎、穿孔。观察各组小鼠术后12、24、36、48、60、72 h的生存率。术后6 h采集各组小鼠尾静脉血,采用 ELISA 检测血清 IL-6,比较此时间点3组存活小鼠间 IL-6水平以及CLP组、CASP组的存活和死亡小鼠间IL-6水平。结果 Sham组、CLP组和CASP组术后72 h生存率分别是100.0%(20/20)、45.0%(9/20)和10.0%(2/20),3组间总体比较差异有统计学意义(字2=32.970,P<0.01),两两比较3组间差异均有统计学意义(P值均<0.05);3组小鼠生存时间曲线经Log-rank检验,差异有统计学意义(字2=34.030,P<0.05)。术后6 h,Sham组、CLP组、CASP组存活小鼠血清 IL-6水平分别是(36.62依10.30) ng/L、(2443.47依970.50) ng/L、(4057.93依827.41)ng/L,差异均有统计学意义(Hc=29.270,P<0.01);CLP组和CASP组各组内存活小鼠血清IL-6水平平均分别为(1348.80依276.25) ng/L、2100.00 ng/L,明显低于死亡小鼠的(3157.29依330.94)ng/L、(4275.48依512.71)ng/L,CLP组差异有统计学意义(t=13.071,P<0.01)。结论两种脓毒症模型小鼠的转归都有一定的病死率,较好地模拟了脓毒症的病理生理过程,CLP模型侧重于模拟局限性腹腔脓肿,CASP模型则侧重于模拟弥漫性腹膜炎。 CLP组模型术后6 h血清IL-6水平较低的小鼠,术后72 h生存率较高。     

Development and characterization of novel anti-C5 monoclonal antibodies capable of inhibiting complement in multiple species

Over the last decade there has been an explosion in complement therapies; one-third of the drugs in the clinic or in development target C5 protein. Eculizumab, a monoclonal antibody (mAb) that binds C5 and blocks its cleavage by the convertase, is the current reference standard treatment for atypical haemolytic uraemic syndrome (aHUS) and paroxysmal nocturnal haemoglobinuria (PNH) and in clinical trials for many other diseases. Here we describe a panel of novel anti-C5 mAb, including mAb that, like Eculizumab, are efficient inhibitors of complement but, unlike Eculizumab, inhibit across species, including human, rat, rabbit and guinea pig. Several inhibitory anti-C5 mAb were identified and characterized for C5 binding and lytic inhibitory capacity in comparison to current therapeutic anti-C5 mAb; three clones, 4G2, 7D4 and 10B6, were selected and further characterized for ligand specificity and affinity and cross-species inhibitory activity. The mAb 10B6 was human-specific whereas mAb 4G2 and 7D4 efficiently inhibited lysis by human, rabbit and rat serum, and weakly inhibited guinea pig complement; 7D4 also weakly inhibited mouse complement in vitro The rat C5-cross-reactive mAb 4G2, when administered intraperitoneally in a rat model of myasthenia gravis, effectively blocked the disease and protected muscle endplates from destruction. To our knowledge this is the first report of an anti-C5 function blocking mAb that permits preclinical studies in rats.     

Inhibition of complement activity by humanized anti-C5 antibody and single-chain Fv

Activation of the complement system contributes significantly to the pathogenesis of numerous acute and chronic diseases. Recently, a monoclonal antibody (5G1.1) that recognizes the human complement protein C5, has been shown to effectively block C5 cleavage, thereby preventing the generation of the pro-inflammatory complement components C5a and C5b-9. Humanized 5G1.1 antibody, Fab and scFv molecules have been produced by grafting the complementarity determining regions of 5G1.1 on to human framework regions. Competitive ELISA analysis indicated that no framework changes were required in the humanized variable regions for retention of high affinity binding to C5, even at framework positions predicted by computer modeling to influence CDR canonical structure. The humanized Fab and scFv molecules blocked complement-mediated lysis of chicken erythrocytes and porcine aortic endothelial cells in a dose-dependent fashion, with complete complement inhibition occurring at a three-fold molar excess, relative to the human C5 concentration. In contrast to a previously characterized anti-C5 scFv molecule, the humanized h5G1.1 scFv also effectively blocked C5a generation. Finally, an intact humanized h5G1.1 antibody blocked human complement lytic activity at concentrations identical to the original murine monoclonal antibody. These results demonstrate that humanized h5G1.1 and its recombinant derivatives retain both the affinity and blocking functions of the murine 5G1.1 antibody, and suggest that these molecules may serve as potent inhibitors of complement-mediated pathology in human inflammatory diseases.     

The clinical role of interleukin-6 and interleukin-6 soluble receptor in human follicular fluids

In order to investigate the role of interleukin-6 (IL-6) and interleukin-6 soluble receptor (sR) in human ovulation, we evaluated the concentrations in human follicular fluid and analyzed the correlation of IL-6 and IL-6 sR with oocyte maturation. The oocytes were obtained from the follicular fluid of 45 women undergoing in vitro fertilization and embryo transfer. The concentrations of IL-6 and IL-6 sR in follicular fluid were measured by ELISA. In addition, granulosa cells obtained from the follicular fluid were cultured and treated with forskolin and 12-o-tetradecanoylphorbol 13-acetate for 24–48 h. The concentration of IL-6 was significantly higher in the follicular fluid than in the serum (P<0.01). In contrast, the concentration of IL-6 sR was significantly lower in the follicular fluid than in the serum (P<0.001). The concentrations of IL-6 and IL-6 sR were significantly higher in the follicular fluid containing mature oocytes than in fluid containing immature oocytes (P<0.05). The production of IL-6 was markedly increased over the basal level after 24 h of treatment with forskolin(P<0.001) and 48 h of treatment (P<0.01) with cultured granulosa cells. Our data suggest that IL-6 and IL-6 sR may play an important role in follicular growth and development in human preovulatory processes. It is possible that IL-6 in particular may be regulated by cAMP. IL-6 and IL-6 sR might also be valuable biochemical markers in the evaluation of oocyte maturation. Received: 6 July 2002 / Accepted: 18 December 2002 Correspondence to Y. Kawano     

Inhibition of C5 or absence of C6 protects from sepsis mortality

Inhibiting complement anaphlytoxin C5a during sepsis may prevent sepsis mortality. Although human anti-C5 antibodies exist, their therapeutic use in microbial sepsis has been avoided because of the hypothesis that inhibiting C5b will prevent formation of the bactericidal membrane attack complex (MAC) and worsen clinical outcome. We wished to test the hypothesis that inhibition of C5 would improve outcomes in sepsis. Sepsis was induced in rats by laparotomy and cecal ligation and puncture (CLP) by an IACUC-approved protocol. Sham animals underwent laparotomy without CLP. Following CLP rats were randomized to receive a single IV dose of purified IgG ant-C5 antibody (Ab) or control IgG Ab. Anti-C5 Ab treated rats (n = 20) had significantly lower mortality vs. controls (n = 21), 20% vs. 52% (P = 0.019, log-rank). Analysis of bacterial load by culture of spleen and liver homogenates showed a reduction in colony forming units in anti-C5 Ab treated rats vs. control IgG (P = 0.003 and 0.009, respectively). Anti-C5 treatment reduced lung injury as measured by total MPO content of lung tissue (P = 0.024). Finally, rats genetically deficient in C6 production, unable to form MAC but capable of producing C5a and C5b, were protected from CLP-induced sepsis mortality. Our results show that in anti-C5 antibody therapy prevents CLP sepsis-induced mortality and improves lung injury. Inhibition of the complement MAC does not increase bacterial load or mortality, therefore, the use of anti-C5 therapy may be beneficial rather than detrimental in sepsis.     

白细胞介素6对哮喘小鼠气道炎症和上皮下纤维化的影响

目的 :研究白细胞介素 6对哮喘小鼠气道炎症和气道结构重建的作用。方法 :雄性BALB C种系小鼠 2 4只 ,随机分成处理组、模型组和对照组 ,每组 8只 ,用卵蛋白致敏和反复激发 4周。每次激发前处理组腹腔内注射 2 0 0 μg白细胞介素 6单克隆抗体 ,模型组注射 2 0 0 μg大鼠IgG ,对照组注射等量的生理盐水。比较 3组气道反应性 (PC1 2 0 )、支气管肺泡灌洗液细胞成分、基底膜和上皮下胶原层厚度的变化。结果 :卵蛋白反复激发诱发小鼠PC1 2 0 显著降低 ,气道内炎症细胞数量明显增多 ,上皮基底膜增厚和上皮下胶原增加。与模型组比较 ,处理组支气管肺泡灌洗液中巨噬细胞、中性白细胞、嗜酸细胞和淋巴细胞明显上升(P <0 0 5 ) ,基底膜和上皮下胶原厚度分别从 (3 1± 0 4 ) μm和 (4 5± 0 3) μm减少至 (2 2± 0 2 ) μm和 (3 5± 0 2 ) μm(P <0 0 5 ) ,但PC1 2 0 无改变 (P >0 0 5 )。结论 :白细胞介素 6在哮喘中的作用是抑制气道炎症和促进气道结构重建。     

成纤维细胞介导的人白细胞介素6基因疗法的建立及其体内白细胞介素6分泌水平的实验研究

细胞因子基因治疗是近年来生物治疗的重要进展。本文以人IL-6基因为治疗目的基因,以成纤维细胞为载体细胞,建立了人IL-6基因疗法的实验模型,并动态观察了其体内IL-6分泌水平.将650bp的人IL-6 cDNA 插入到携有Neo~R 基因的表达载体BCMGNeo 的Xho I 位点上,对此重组表达载体进行限制性酶切鉴定。用磷酸钙共沉淀法将BCMGNeo-IL-6转入NIH3T3成纤维细胞中,通过G418抗性筛选、有限稀释和上清中IL-6活性的测定,从多株阳性克隆中筛选到一株高分泌IL-6(184.6U/ml)的克隆株。对此阳性克隆进行了Southern 杂交分析。将此阳性克隆体外扩增、包裹入胶原中,然后移植入小鼠腹腔内,可从小鼠血清中(直至移植后15天)检测出IL-6,明成纤维细胞能成功地将IL-6基因导入体内并有效表达,证明该基因疗法是可行的。     

Increased and highly stable levels of functional soluble interleukin-6 receptor in sera of patients with monoclonal gammopathy

Soluble human interleukin-6 receptor (sIL-6R) was measured in the serum of 30 healthy individuals, 32 individuals with monoclonal gammopathy of undetermined significance (MGUS), 20 patients with early multiple myeloma (MM) and 54 patients with overt MM. The serum activity recognized by an immunoradiometric assay was determined to be sIL-6R, because of its binding capacity to IL-6 and its molecular mass of 55 kDa. All sera of healthy individuals contained sIL-6R (mean value: 89 ng/ml, range 17-300 ng/ml). Serum sIL-6R levels were increased by 51% in patients with MGUS (mean value: 135 ng/ml, p<0.005), by 44% in patients with early myeloma (mean value: 128 ng/ml, p<0.001) and by 116 % in patients with overt MM (mean value: 193 ng/ml, p<0.001). In patients with MM, a complete lack of correlation (p>0.7) was found between serum sIL-6R levels and other previously recognized prognostic factors in this disease, particularly serum IL-6 levels and those factors related to tumor cell mass. The independence of serum sIL-6R levels on tumor cell mass was directly demonstrated by studying four patients with MM treated with autologous bone marrow transplantation for periods of between 320 and 760 days. These levels were found to be remarkably stable and constant, independent of whether patients relapsed or achieved complete remission. Finally, physiological concentrations of sIL-6R were found to increase by tenfold the sensitivity of human myeloma cell lines to IL-6. These observations suggest a high control of the sIL-6R level in vivo, and, possibly, an important functional role of this circulating protein in patients with monoclonal gammopathies.     

Treatment with anti-C5aR mAb leads to early-onset clinical and mechanistic effects in the murine delayed-type hypersensitivity arthritis model

Abstract

Blockade of the complement cascade at the C5a/C5a receptor (C5aR)-axis is believed to be an attractive treatment avenue in rheumatoid arthritis (RA). However, the effects of such interventions during the early phases of arthritis remain to be clarified. In this study we use the murine delayed-type hypersensitivity arthritis (DTHA) model to study the very early effects of a blocking, non-depleting anti-C5aR mAb on joint inflammation with treatment synchronised with disease onset, an approach not previously described. The DTHA model is a single-paw inflammatory arthritis model characterised by synchronised and rapid disease onset driven by T-cells, immune complexes and neutrophils. We show that a reduction in paw swelling, bone erosion, cartilage destruction, synovitis and new bone formation is apparent as little as 60?h after administration of a single dose of a blocking, non-depleting anti-mouse C5aR mAb. Importantly, infiltration of neutrophils into the joint and synovium is also reduced following a single dose, demonstrating that C5aR signalling during the early stage of arthritis regulates neutrophil infiltration and activation. Furthermore, the number of T-cells in circulation and in the draining popliteal lymph node is also reduced following a single dose of anti-C5aR, suggesting that modulation of the C5a/C5aR axis results in effects on the T cell compartment in inflammatory arthritis. In summary, these data demonstrate that blockade of C5aR leads to rapid and significant effects on arthritic disease development in a DTHA model strengthening the rationale of C5aR-blockade as a treatment strategy for RA, especially during the early stages of arthritis flare.     

Regulation of IL-8 production by complement-activated product,C5a,in vitro and in vivo during sepsis

Excessive complement-activated product complement 5a (C5a) has been implicated in the pathogenesis of sepsis development. Herein, we employed in vitro and in vivo models of sepsis to investigate the functional relationship between overtly produced C5a and IL-8. Our data revealed that C5a could strongly amplify IL-8 expression from human whole blood cells induced by LPS and other types of TLR agonists. ERK1/2 and p38, but not JNK, were mainly participated in signaling pathways for IL-8 production. In the whole blood stimulated by Escherichiacoli, C5a levels were quickly elevated and blockage of C5a significantly decreased E. coli-elicited IL-8 production. In the mouse model of sepsis induced by cecal ligation and puncture (CLP), the markedly increased keratinocyte-derived cytokine (KC) could be strongly suppressed by blockage of C5a. These data suggest that excessive C5a functions as a critical inflammatory mediator to enhance IL-8 production mainly through MAPK signaling pathways.     

Differential regulation of interleukin-6 receptors by interleukin-6 and interferons in multiple myeloma cell lines

Interleukin-6 (IL-6) mediates pleiotropic functions through specific receptors (IL-6R) composed of an 80-kDa binding protein, associated with a non-ligand binding protein (gp130) which transduces the signal. Because IL-6 is the major tumor growth factor in multiple myeloma, we investigated the regulation of IL-6R in two human multiple myeloma cell lines. Binding experiments with ¹²⁵I-labeled IL-6 showed that IL-6R were expressed at a high density on RPMI-8226 cells (15 000 receptors/cell), but no specific binding was detected on XG-1 cells, whose growth depends on the presence of exogenous IL-6. However, when IL-6 was removed from the culture medium, high-affinity IL-6R appeared on the surface of XG-1 cells (5300 sites/cell). Treatment of RPMI-8226 cells with IL-6 reduced the number of IL-6R without changing their affinity. This reduction was dose dependent and was not affected by acid treatment which dissociates ligand-receptor complexes. Cross-linking experiments showed that the formation of one IL-6/receptor complex of 160 kDa markedly decreased upon IL-6 treatment, while the other complex of 190 kDa became undetectable. These data provide evidence for ligand-induced down-regulation of membrane IL-6R expression in myeloma cells. Treatment of RPMI-8226 cells with interferon-α (IFN-α), which inhibits the growth of these cells, stimulated IL-6R expression and increased the formation of the 160-kDa IL-6/receptor complex. This stimulation was specific for IFN-α, since IFN-γ reduced the number of IL-6R. These data indicate that, in myeloma cells, IL-6R are differentially regulated by IL-6 and IFN-α.     

Inhibition of human IgE synthesis by anti-IgE antibodies requires divalent recognition

We used a selection of well-characterized murine monoclonal anti-IgE antibodies to investigate their effect on human in vitro IgE synthesis. We found anti-IgE antibodies that either inhibited or enhanced interleukin-4 plus anti-CD40-induced in vitro IgE synthesis in peripheral blood mononuclear cells (PBMC). This differential activity was isotype specific as neither IgM nor IgG synthesis were affected. Interestingly, only coding IgE mRNA was down-regulated, whereas germ-line ε RNA expression was not influenced by anti-IgE monoclonal antibody (mAb). On purified B cells all anti-IgE mAb inhibited interleukin-4 plus anti-CD40-induced IgE synthesis, implying a role of non-B cells for the enhancing activity observed in PBMC. Using Fab and F(ab')₂ of an inhibitory anti-IgE mAb we could show that divalent recognition was required for inhibition of IgE synthesis.     

Biological activity of recombinant murine interleukin-6 in interleukin-1 T cell assays

Interleukin-6 (also called B cell stimulatory factor 2, hepatocyte activating factor, interferon-β₂) has been shown to have effects on various lineages of hemopoietic cells. Some of its activities appear to overlap those of interleukin-1. In particular, recombinant murine IL-6 induced proliferation of phytohemagglutinin-activated thymocytes, an assay widely used to detect IL-1. In this report, we compared several features of IL-1 and IL-6 dependent thymocyte proliferation. The results indicate that IL-2 is the major second mediator of both IL-1 and IL-6 dependent proliferation. Finally, we tested whether IL-6 would also have activity in other T cell-based IL-1 assays using the T cell lymphoma LBRM33 1A5 and the T cell clone D10-G4.1. IL-6 had no activity in the latter two assays. These results indicate that IL-1 assays using LBRM33 1A5 and D10-G4.1 selectively detect Il-1, and are more specific assays for the detection of IL-1 in samples that may also contain IL-6.     

白细胞介素13抑制肾小球系膜细胞增殖及白细胞介素6表达

目的:探讨白细胞介素13(IL-13)对体外培养的大鼠系膜细胞的增殖及其产生白细胞介素6(IL-6)的影响。方法:用四甲基偶氮唑(MTT)法测定系膜细胞增殖,用逆转录聚合酶链反应(RT-PCR)及酶联免疫吸附法(ELISA)测定系膜细胞IL-6mRNA表达及其蛋白水平。结果:IL-13在1、10、100μg/L浓度范围呈剂量依赖性地抑制系膜细胞的增殖;5%FCSRPMI1640培养条件下系膜细胞IL-6mRNA表达及IL-6分泌水平较低,脂多糖(LPS)可刺激系膜细胞IL-6mRNA的表达及提高IL-6分泌水平,而IL-13可抑制LPS诱导的系膜细胞IL-6分泌及其mRNA表达。结论:IL-13抑制体外培养的系膜细胞增殖及LPS诱导的系膜细胞IL-6的产生,IL-13可能对于肾小球肾炎的系膜细胞炎症反应具有拮抗作用。     

Limited involvement of interleukin-6 in the pathogenesis of lethal septic shock as revealed by the effect of monoclonal antibodies against interleukin-6 or its receptor in various murine models.

Several studies in human patients and in laboratory animals have revealed a correlation between serum interleukin (IL)-6 levels and outcome in clinical sepsis and in related animal models, respectively. In the present study, two monoclonal antibodies were used to investigate the contribution of IL-6 in the lethal action of tumor necrosis factor (TNF) and of lipopolysaccharide (LPS) in mice. We studied the potential protective properties of an anti-murine (m) IL-6 antibody and of an anti-mIL-6 receptor antibody. In controlled experiments, we observed that both monoclonal antibodies conferred a dose-dependent protection to a lethal dose of mTNF. Detailed studies with the monoclonal antibodies indicate, however, that protection was no longer observed when the mTNF dose was slightly higher than the lethal dose. Likewise, the anti-IL-6 monoclonal antibody protected against injections of LPS at a lethal-dose concentration, but here too failed to protect against higher doses of LPS. The anti-IL-6 monoclonal antibody was unable to protect against mTNF in mice sensitized by galactosamine, the corticoid receptor antagonist RU38486 or human (h) IL-1 beta. Protection did not correlate with the serum concentrations of IL-6. Finally, we demonstrate that hIL-6 injection did not change the sensitivity of mice towards mTNF. We conclude that, although IL-6 levels may be of value as a marker for the outcome in septic shock, this cytokine contributes only marginally in the pathogenesis leading to death. The small, but real, contribution of IL-6 in some situations might be due to its ability to up-regulate the level of TNF receptors.     

Selection of phage-displayed anti-guinea pig C5 or C5a antibodies and their application in xenotransplantation

Xenogeneic liver transplantation in the discordant guinea pig (gp) to rat model results in hyperacute rejection within a few minutes, which is due to activation of the complement system. Currently no antibodies against gp complement factors are available, which allow activation of the gp complement system in serum or complement deposition in tissue to be detected. To close this gap, we started developing single chain Fvs (scFvs) against gpC5 and gpC5a.

We generated a combinatorial library of scFv antibodies comprising the variable heavy and light chain repertoire from mice immunized with gpC5. Out of this library we selected several antibodies against gpC5 and C5a after four and six rounds of biopanning, respectively. Selected gpC5-specific scFvs were purified by metal affinity chromatography followed by size exclusion chromatography or by affinity chromatography using Protein L. Purified scFvs were able to inhibit gp complement system in a hemolytic assay and to detect gpC5 deposition in tissue. A surface plasmon resonance based assay on BIAcore was established, with which the C5 concentration in gp serum was determined to 240 μg/ml. As at least 0.04% of the normal gpC5 concentration can be detected, the test provides a powerful tool to investigate the development and the consequence of a hybrid complement system after liver xenotransplantation from gp to rat.     

Activation of the gp130 signaling pathway by monoclonal antibodies directed against the gp130 molecule

Six cytokines of the interleukin (IL)-6 family involved in various inflammatory or tumoral diseases share the same gp130 signal transducer chain. We made a panel of anti-gp130 monoclonal antibodies (mAb) to study the structure and function of the gp130 molecule. These mAb recognized different epitopes of the gp130 that we called A to J. Most of the mAb were found to be inhibitors and we studied whether some of them could also induce gp130 activation. When used alone, none of them was able to initiate the proliferation of IL-6-dependent cell lines. However, some particular associations of the mAb were able to induce a proliferative response. mAb B1 could activate the lines in association with F1 or with I2 but not with I1, which in ELISA was similar to I2. In contrast mAb B2, which in ELISA appeared to be very similar to B1, was able to activate the cells in association with I1 but not with F1 or I2. Two other mAb belonging to specificities A and C were found to be activators either in association with I1 only, or with I1 or B2, respectively. These associations of mAb appeared to be nearly as potent activators as IL-6 itself. Although we still have no precise idea of the mechanisms involved, they are interesting tools to study the molecular interactions leading to gp130 activation and, from a practical point of view, valuable growth factors of hematopoietic stem cells.