Wistar大鼠胶原诱导的关节炎造模因素的分析

目的通过比较不同的造模方法,分析影响胶原诱导关节炎（collagen-induced arthritis,CIA）大鼠模型建立的因素。方法选用Wistar大鼠造模,通过改变性别、剂量、年龄、注射部位及免疫方式,来比较造模成功率。结果不同性别、剂量、年龄及免疫方式造模成功率不同。结论4～5周龄Wistar雌性大鼠,初次免疫注射乳剂4点共0.20 mL,加强免疫在14 d之后3点共0.15 mL的造模成功率最高。     

T淋巴细胞与胶原诱导性关节炎

胶原诱导性关节炎是应用较广泛的人类风湿性关节炎动物模型 ,二者在发病机制及病理学改变上极为相似。近年来研究证实激活的某些T细胞在胶原诱导性关节炎的发病过程中起着重要作用 ,尤其在疾病的起始阶段 ,提示胶原诱导性关节炎可能是以T淋巴细胞介导为主的自身免疫性疾病     

人工环境影响胶原诱导性关节炎的免疫及内分泌观察

在大鼠胶原诱导性关节炎（ＣＩＡ）的诱导阶段,给予风寒湿或风湿热刺激,结果显示：１．风寒湿显著降低雌性鼠炎症积分,延迟起病时间。２．风寒湿,风湿热均可显著提高雌性鼠的胶原抗体水平。３．风寒湿显著降低雄性鼠的类风湿因子水平。风湿热显著降低雌性鼠类风湿因子水平。４．风寒湿显著升高雌性鼠血清Ｅ２及Ｔ３含量。提示：１．环境因素对ＣＩＡ的影响具有性别差异,单纯风寒湿环境刺激ＣＩＡ不能作为类风湿性关节炎风寒湿痹模型。２．风寒湿与风湿热均可促进雌性鼠炎症启动阶段的抗体形成。３．风寒湿促进雌性鼠Ｅ２的分泌可能是关节炎症程度降低的主要原因。     

鸡Ⅱ型胶原基因疫苗pcDNA-CCOL2A1能有效治疗大鼠类风湿性关节炎

已证明Ⅱ型胶原(CII)是类风湿性关节炎(RA)最主要的自身免疫抗原, 采用口服鸡Ⅱ型胶原蛋白(CCII)诱导免疫耐受治疗RA标志着RA治疗策略的重大进展之一. 在国际上克隆成功鸡Ⅱ型胶原蛋白基因(CCOL2A1)的基础上, 探讨了采用pcDNA-CCOL2A1基因疫苗策略治疗RA的科学性和可行性. 将克隆的CCOL2A1基因连接于真核表达载体pcDNA3.1(＋)上, 即为基因疫苗pcDNA-CCOL2A1. 然后将该表达载体pcDNA-CCOL2A1 转染COS-7细胞, 经Western blot分析显示, pcDNA-CCOL2A1在COS-7细胞中是以分泌型来表达CCII多肽链的α亚单位. 随后, 以CCII诱导的 Wistar大鼠为RA模型即CIA, 系统观察一次性尾部静脉注射20, 200, 400 μg/kg 3个不同剂量pcDNA-CCOL2A1基因疫苗对CIA关节炎的治疗作用. 结果表明, 在注射后第5天200 μg/kg组就可观察到大鼠关节肿胀程度明显减轻, 与空载体组比较有显著性差异(P <0.05), 而20, 400 μg/kg两剂量组与空载体组比较未观察到治疗效果(P>0.05). 注射后6周, CIA大鼠血清中抗CII抗体浓度水平、TNF-α浓度在200 μg/kg治疗组较空载体组明显降低(P<0.05), 而400 μg/kg组则显著的升高, 20 μg/kg组则无明显变化. 此外, 细胞因子TGF-β, IL-10浓度水平在200 μg/kg组较空载体组明显升高(P<0.05), 而20与400 μg/kg两组则无显著性差异. 脾细胞淋巴细胞增殖实验表明, 200 μg/kg剂量pcDNA-CCOL2A1基因疫苗治疗组大鼠脾细胞对CII的反应能力较空载体组明显下降(P<0.05). 此结果表明, 200 μg/kg剂量pcDNA-CCOL2A1基因疫苗能明显抑制CIA大鼠关节肿胀程度, 降低抗CII抗体、TNF-α水平, 提高细胞因子TGF-β, IL-10水平, 降低脾细胞增殖反应能力, 对CIA大鼠关节炎有显著的治疗作用.     

胶原诱导型关节炎大鼠的关节影像学特点

目的旨在分析CIA X线片四肢关节的破坏特点,揭示CIA大鼠关节破坏的规律,为规范评分方案提供依据。方法采用П型胶原和弗氏完全佐剂皮下注射清洁级Wistar大鼠,造模成功（每批10只,共3次）后第35天行全身X线钼靶照片,以正常组作为对照、每只大鼠评价96块骨破坏（erosion）和100个关节间隙（joint space narrowing,JSN）;处死动物,取左前肢和右后肢近端第3足趾关节苏木素-伊红（HE）染色,评价中性粒细胞、淋巴细胞、浆细胞浸润、滑膜增生和软骨破坏的情况。结果造模成功后CIA大鼠关节出现明显的红肿,活动受限;HE病理显示,CIA关节存在明显的中性粒细胞、淋巴细胞和浆细胞浸润,滑膜增生,纤维组织增生,软骨破坏;X线片分析结果显示：①广泛性骨质疏松,边缘性骨质侵蚀,关节间隙狭窄或增宽,部分踝关节间隙消失,关节相互融合甚至骨性强直。②67%的骨出现erosion,JSN影响为78%,关节破坏以中、重度为主;③远端、近端趾间关节和踝关节发病率高,损害严重,掌趾关节发病率低,破坏较轻。④后肢关节破坏重于前肢（P〈0.01）,左右肢没有显著性差异（P〉0.05）。结论①滑膜是CIA炎症反应启动的主要病灶,与骨交界的滑膜和血管翳造成了CIA的骨质破坏;②CIA影像学表现关节破坏严重,以远端、近端趾间关节和踝关节为主,这些关节可作为评价破坏程度的选择。本研究对于深入CIA关节破坏的病因病理和进一步规范X线片评分方案具有一定意义。     

TRV病毒诱导大豆基因沉默体系优化及应用

病毒诱导的基因沉默（virus-induced gene silencing,VIGS）技术已广泛用于植物基因功能研究,以烟草脆裂病毒（tobacco rattle virus, TRV）为载体的沉默体系介导大豆基因沉默效率有待明确,采用无缝克隆技术构建TRV-VIGS沉默体系,探索不同接种方法对大豆靶基因在不同组织间的沉默效率,为大豆基因功能研究提供依据。以八氢番茄红素去饱和酶（phytoene desaturase, GmPDS）及泛素连接酶（GmATL3）基因为靶基因,将含有pTRV1和重组载体菌液采用注射、灌根（agroinoculation）、注射与灌根相结合3种方法分别接种大豆中黄13,接种28 d观察沉默表型现象,并使用RT-qPCR技术检测根部与叶部基因相对表达量,明确不同方法沉默效果。注射接种的大豆叶边缘及叶内出现黄化褪绿,灌根接种与注射加灌根接种的叶片表面出现褪绿斑点及褶皱褪绿表型。RT-qPCR结果表明,3种接种方法对沉默GmPDS效果接近100%;注射接种对GmATL3的沉默效率在叶部为80%-95%,根部为40%-60%;灌根与注射加灌根接种,根部沉默效率为7...     

高羊茅FaChit1基因cDNA克隆及诱导表达

应用简并RT-PCR及RACE技术,从高羊茅中克隆了1个Ⅰ类几丁质酶基因cDNA全长序列,命名为FaChit1.结果表明,该cDNA具有1个951 bp的完整编码框,编码316个氨基酸,其编码产物和其它植物的Ⅰ类几丁质酶在氨基酸序列上具有较高的同源性,包含典型的几丁质结合区、催化区以及脯氨酸、半胱氨酸富集的铰链区,但缺少定位到植物液泡所必须的C末端延伸区靶向信号.Northern杂交显示,FaChit1对真菌激发子有较强的响应,乙烯和干旱胁迫均能有效诱导FaChit1基因的表达,而对机械损伤处理的反应比较微弱,只在叶片中积累少量的mRNA.     

探讨HLA-DR_4基因与类风湿关节炎的相关性

RA是一种慢性自身免疫性疾病,其发病机制目前还不是很清楚,有大量的研究表明RA为多基因遗传性疾病,其中HLA-DR_4基因不仅和RA的发病率相关,并且和病情的严重程度有关。检测HLA-DR_4基因,对于预测RA易感患者同时估计和判断RA患者的病情进程和预后都有特殊的意义。     

TGF-beta1通过抑制HIF-1alpha减少风湿性心脏病心肌细胞胶原合成

目的:探讨缺氧诱导因子-1α(HIF-1α)在转化生长因子β1(TGF-β1)促风湿性心脏病心肌细胞胶原合成中的作用。方法:以体外培养风湿性心脏病(风心病)患者经瓣膜置换术后留取组织分离而来的心肌细胞为研究对象,依据加入TGF-β1的浓度将前期实验分为四组:0,5,10及20(μg/L),观察TGF-β1对风湿性心脏病心肌细胞胶原合成及HIF-1α表达的影响;而后实验选取10μg/L TGF-β1为干预浓度,将Scrambled si RNA或HIF-1αsi RNA转染入细胞内。48小时后,分别收集各组细胞,采用RT-PCR检测I型胶原的m RNA水平,Western Blot技术测定细胞内I型胶原和HIF-1α的蛋白表达水平。结果:与0、5及10μg/L浓度TGF-β1组相比,5、10及20μg/L浓度的TGF-β1分别显著地增加了风心病心肌细胞I型胶原及HIF-1α的表达。另外,HIF-1αsi RNA则明显减少了TGF-β1诱导的心肌细胞I型胶原生成。结论:HIF-1α介导了TGF-β1对风湿性心脏病心肌细胞I型胶原合成的促进作用。     

丹参胁迫诱导基因SmSIP1的表达特征分析

从丹参EST库中筛选到一个胁迫诱导蛋白基因,命名为SmS1P1,其序列全长296bp,编码80个氨基酸。生物信息学预测表明SmS1P1是一个亲水的,不具有跨膜结构域,包含一个N-端信号肽和多个可能的磷酸化位点的蛋白。实时荧光定量PCR分析显示,SmS1P1在根中的表达量高于茎和叶,并且受ABA和干旱的诱导,推测其可能参与根部的胁迫应答反应。     

Reduced incidence and severity of collagen-induced arthritis in mice lacking IL-18

We have recently reported the presence and a potential proinflammatory role of IL-18 in the synovium of patients with rheumatoid arthritis. To obtain direct evidence that IL-18 plays an influential role in articular inflammation, we investigated the development of collagen-induced arthritis in a strain of mice lacking IL-18 (IL-18(-/-)) of DBA/1 background. IL-18(-/-) mice developed markedly reduced incidence of arthritis compared with heterozygous or wild-type mice. Of the IL-18(-/-) mice that developed arthritis, the severity of the disease was significantly reduced compared with the intact mice. This was accompanied by reduced articular inflammation and destruction evident on histology. IL-18(-/-) mice also had significantly reduced Ag-specific proliferation and proinflammatory cytokine (IFN-gamma, TNF-alpha, IL-6, and IL-12) production by spleen and lymph node cells in response to bovine type II collagen (CII) in vitro compared with wild-type mice, paralleled in vivo by a significant reduction in serum anti-CII IgG2a Ab level. Treatment with rIL-18 completely reversed the disease of the IL-18(-/-) mice to that of the wild-type mice. These data directly demonstrate a pivotal role of IL-18 in the development of inflammatory arthritis and suggest that antagonists to IL-18 may have therapeutic potential in rheumatic diseases.     

Rap1A regulates generation of T regulatory cells via LFA-1-dependent and LFA-1-independent mechanisms

The small GTPase Rap1A has a critical role in regulating cell-matrix and cell-cell adhesion. In T lymphocytes, Rap1A mediates LFA-1 activation and LFA-1-mediated adhesion. LFA-1 reduces the threshold of TCR signals for low affinity ligands. Previously, we determined that mice expressing constitutively active Rap1A on T cells have increased frequency of CD103⁺ T regulatory cells (Treg). We hypothesized that Rap1A-GTP might affect the differentiation of Treg by regulating LFA-1 activation. Using Foxp3-GFP-KI, LFA-1-KO and Rap1A-GTP-Tg mice we determined that Rap1A has an active role in the development of thymic Treg but LFA-1 is not mandatory for this function. Rap1A is also involved in the generation of peripheral Treg and this effect is mediated via LFA-1-dependent and LFA-1-independent mechanisms. Identification of the signaling pathways via which Rap1-GTP contributes to the differentiation of Treg will provide new insights to the function of Rap1A and to designing targeted approaches for generation of Treg for therapeutic applications.     

Acceleration and increased severity of collagen-induced arthritis in P-selectin mutant mice.

P-selectin plays an important role in leukocyte adherence to microvascular endothelium and is expressed in synovial tissue from patients with rheumatoid arthritis (RA). However, the contribution of P-selectin to the initiation and chronicity of joint inflammation is not well understood. In these studies, collagen-induced arthritis (CIA) was induced in P-selectin mutant (-/-) mice to explore the role of P-selectin in the development of joint inflammation. Surprisingly, CIA onset was accelerated and severity was increased in P-selectin mutant mice, compared with wild-type mice (+/+). Increased levels of anti-type II collagen IgG were detected in both nonarthritic and arthritic P-selectin mutant mice from days 14-91. In addition, splenocytes isolated from immunized and nonimmunized P-selectin mutant mice produced significantly less IL-2 and IL-4, but significantly higher levels of IL-10 and IL-5 than splenocytes from wild-type mice. These observations show that P-selectin-mediated leukocyte rolling is not required for the development of murine CIA and that P-selectin expression exerts a controlling effect on the development of Ag-driven inflammatory joint disease, possibly by mediating the recruitment and/or trafficking of specific leukocyte subtypes into lymphoid tissue or inflammatory foci.     

LFA-1 Binding Site in ICAM-3 Contains a Conserved Motif and Non-Contiguous Amino Acids

The intercellular adhesion molecule-3 (ICAM-3) is a counter receptor for the integrin LFA-1 that supports cell-cell adhesion dependent functions. ICAM-3 is a member of the immunoglobulin superfamily possessing five immunoglobulin-like domains. Here, we characterize the overall shape of ICAM-3 and the amino acid residues involved in binding LFA-1 and monoclonal antibodies (Mab). Electron microscopic observations show that ICAM-3 is predominantly a straight rod of 15 nm in length, suggesting a head to tail arrangement of the immunoglobulin-like domains. Six out of nine ICAM-3 Mab described blocked the interaction with LFA-1 to varying degrees. Domain assignment of blocking Mab epitopes and characterization of LFA-1-dependent cell adhesion to ICAM-3 mutants demonstrate that the amino-terminal domain of ICAM-3 interacts with LFA-1. A conserved amino acid motif including residues E37 and T38 form an integrin binding site (IBS) in ICAM-3. This motif has also been shown to function as an IBS in ICAM-1 and VCAM-1 and hence may form a common site of contact in all CAMs of this type. Other ICAM-3 residues critical to adhesive interactions, such as Q75, conserved in ICAM-1 and ICAM-2, but not VCAM-1, may confer specificity to LFA-1 binding. This residue, Q75, is predicted to locate in a model of ICAM-3 to the same site as RGD in the immunoglobulin-like domain of fibronectin that binds several integrins. This suggests an evolutionary relationship between ICAMs and fibronectin interactions with integrins.     

LFA-1 Binding Site in ICAM-3 Contains a Conserved Motif and Non-Contiguous Amino Acids

The intercellular adhesion molecule-3 (ICAM-3) is a counter receptor for the integrin LFA-1 that supports cell-cell adhesion dependent functions. ICAM-3 is a member of the immunoglobulin superfamily possessing five immunoglobulin-like domains. Here, we characterize the overall shape of ICAM-3 and the amino acid residues involved in binding LFA-1 and monoclonal antibodies (Mab). Electron microscopic observations show that ICAM-3 is predominantly a straight rod of 15 nm in length, suggesting a head to tail arrangement of the immunoglobulin-like domains. Six out of nine ICAM-3 Mab described blocked the interaction with LFA-1 to varying degrees. Domain assignment of blocking Mab epitopes and characterization of LFA-1-dependent cell adhesion to ICAM-3 mutants demonstrate that the amino-terminal domain of ICAM-3 interacts with LFA-1. A conserved amino acid motif including residues E37 and T38 form an integrin binding site (IBS) in ICAM-3. This motif has also been shown to function as an IBS in ICAM-1 and VCAM-1 and hence may form a common site of contact in all CAMs of this type. Other ICAM-3 residues critical to adhesive interactions, such as Q75, conserved in ICAM-1 and ICAM-2, but not VCAM-1, may confer specificity to LFA-1 binding. This residue, Q75, is predicted to locate in a model of ICAM-3 to the same site as RGD in the immunoglobulin-like domain of fibronectin that binds several integrins. This suggests an evolutionary relationship between ICAMs and fibronectin interactions with integrins.     

Anti-(human LFA-1) monoclonal antibodies bind P815 murine tumour cells

Summary Using anti-CD11a and anti-CD18 monoclonal antibodies (mAbs) directed respectively against the and the chains of LFA-1, we obtained an important and specific staining of P815 murine tumour cells. Both ascitic and cultured cells displayed a positive staining. Other murine tumours of haematopoietic origin, as well as lymphocytes or lymphoblasts from DBA/2 mice, were not labelled by the same monoclonal antibodies. These results were surprising since, to our knowledge, no case of cross-reaction between species has been reported with LFA-1. Moreover, competition assays showed that epitopes recognized by the two anti-CD11a antibodies were different from those identified by H35.89.9, a mAb raised against the murine LFA-1 chain. Using allogeneic cytotoxic T lymphocytes, we also showed that anti-(human LFA-1) mAbs were unable to block the lysis of P815 by these effector cells. Thus, the putative functional properties of these structures, as well as their importance from an antigeneic point of view, remain to be assessed.     

Adenovirus-mediated gene transfer of adiponectin reduces the severity of collagen-induced arthritis in mice

Adiponectin (APN) is a hormone released by adipose tissue with anti-inflammatory properties. The purpose of this study was to examine the therapeutic effects of systemic delivery of APN in murine arthritis model. Collagen-induced arthritis (CIA) was induced in male DBA1/J mice, and adenoviral vectors encoding human APN (Ad-APN) or beta-galactosidase (Ad-β-gal) as control were injected either before or during arthritis progression. Systemic APN delivery at both time points significantly decreased clinical disease activity scores of CIA. In addition, APN treatment before arthritis progression significantly decreased histological scores of inflammation and cartilage damage, bone erosion, and mRNA levels of pro-inflammatory cytokines in the joints, without altering serum anti-collagen antibodies levels. Immunohistochemical staining showed significant inhibition of complement C1q and C3 deposition in the joints of Ad-APN infected CIA mice. These results provide novel evidence that systemic APN delivery prevents inflammation and joint destruction in murine arthritis model.     

Natural killer T cells promote collagen-induced arthritis in DBA/1 mice

The role of NKT cells in the pathogenesis of collagen-induced arthritis (CIA) remains unclear since most studies have used C57BL/6 (B6) mice, which are less susceptible to CIA than mice with a DBA/1 background. To clarify the immunological functions of NKT cells in CIA, it is necessary to analyze in detail the effects of NKT cell deficiency on CIA development in DBA/1 mice. The incidence and severity of CIA were significantly exacerbated in DBA/1CD1d^+/− mice as compared to DBA/1CD1d^−/− mice. In DBA/1CD1d^+/− mice, antigen-specific responses of B and T cells against CII were remarkably increased and inflammatory cytokine levels were also increased in vivo and in vitro. The number of IL-17-producing NKT cells significantly increased in DBA/1CD1d^+/− mice as the disease progressed. Our results clearly show that NKT cells are involved not only in accelerating the severity and incidence of CIA but also in perpetuating the disease progression.     

Resistance to collagen-induced arthritis in SHPS-1 mutant mice

SHPS-1 is a transmembrane protein that binds the protein tyrosine phosphatases SHP-1 and SHP-2 through its cytoplasmic region and is abundantly expressed on dendritic cells and macrophages. Here we show that mice expressing a mutant form of SHPS-1 fail to develop type-II collagen (CII)-induced arthritis (CIA), a model for rheumatoid arthritis in humans. Histological examinations of the arthritic paws from immunized wild-type mice revealed that cartilage was destroyed in association with marked mononuclear cell infiltration, while only mild cell infiltration was observed in immunized SHPS-1 mutant mice. Consistently, the serum levels of both IgG and IgG2a specific to CII and of IL-1β in immunized SHPS-1 mutant mice were markedly reduced compared with those apparent for wild-type mice. The CII-induced proliferation of, and production of cytokines by, T cells from immunized SHPS-1 mutant mice were reduced compared to wild-type cells. These results suggest that SHPS-1 is essential for development of CIA.     

Defective generation of a humoral immune response is associated with a reduced incidence and severity of collagen-induced arthritis in microsomal prostaglandin E synthase-1 null mice

Microsomal PGE synthase-1 (mPGES-1) is an inducible enzyme that acts downstream of cyclooxygenase and specifically catalyzes the conversion of PGH(2) to PGE(2). The present study demonstrates the effect of genetic deletion of mPGES-1 on the developing immunologic responses and its impact on the clinical model of bovine collagen-induced arthritis. mPGES-1 null and heterozygous mice exhibited decreased incidence and severity of arthritis compared with wild-type mice in a gene dose-dependent manner. Histopathological examination revealed significant reduction in lining hyperplasia and tissue destruction in mPGES-1 null mice compared with their wild-type littermates. mPGES-1 deficient mice also exhibited attenuation of mechanical nociception in a gene dose-dependent manner. In addition, mPGES-1 null and heterozygous mice showed a marked reduction of serum IgG against type II collagen, including subclasses IgG1, IgG2a, IgG2b, IgG2c, and IgG3, compared with wild-type mice, which correlated with the reduction in observed inflammatory features. These results demonstrate for the first time that deficiency of mPGES-1 inhibits the development of collagen-induced arthritis, at least in part, by blocking the development of a humoral immune response against type II collagen. Pharmacologic inhibition of mPGES-1 may therefore impact both the inflammation and the autoimmunity associated with human diseases such as rheumatoid arthritis.