组蛋白诱导抗核抗体产生及其对肾脏损害

目的 寻找系统性红斑狼疮中诱导抗核抗体（ANA）生成的真正的自身核成分免疫原。方法 从Con A活化的脾淋巴细胞中提取组蛋白免疫同系BALB／c小鼠,ELISA方法测定IgG类抗组蛋白、抗dsDNA抗体,免疫荧光法检测抗核抗体核型和免疫复合物在肾小球内的沉积,免疫印迹法测定抗可溶性核抗原抗体,考马斯亮蓝法检测尿蛋白含量,光镜下观察肾脏形态变化,电镜下观察肾小球电子致密物。结果 活性组蛋白诱导IgG类抗组蛋白、抗dsDNA等多种抗核抗体生成,且诱发同系小鼠产生SLE样肾脏病理变化。结论 活性组蛋白是诱发抗核抗体生成、造成肾损害的免疫原之一。     

活化淋巴细胞与慢性GVHR诱导的SLE样小鼠模型的比较

目的 :将本室建立的用活化淋巴细胞诱导的系统性红斑狼疮 (SLE)样小鼠模型与国际上公认的用慢性GVHR诱导的SLE样小鼠模型进行比较 ,进一步探索SLE的发病机理。方法 :分别将亲代Balb c小鼠淋巴细胞经静脉和用ConA活化的(Balb c×C5 7BL 6 )F1代小鼠淋巴细胞经皮下途径输入F1代小鼠 ,用ELISA测定IgG类抗dsDNA抗体和抗组蛋白抗体 ,用免疫荧光法检测抗核抗体 (ANA)荧光核型和肾小球内免疫复合物沉积 ,用免疫印迹法检测抗可溶性核抗原 (ENA)抗体。结果 :亲代淋巴细胞免疫F1代小鼠所致的慢性GVHR和活化F1代小鼠淋巴细胞均可诱导F1代小鼠产生高滴度的抗dsDNA抗体、抗组蛋白抗体等ANA ,并且肾脏都有明显的IgG类免疫复合物沉积。但亲代淋巴细胞免疫组ANA核型以颗粒型、核仁型为主 ,ENA多肽谱多在 32、47、6 7kD处显色 ;而活化淋巴细胞免疫组以胞浆型、周边型、均质型为主 ,ENA多肽谱在 2 8、47、6 7kD处显色。结论 :这 2种方法均可诱导出SLE样综合征 ,但其抗核抗体谱有所不同。     

活性染色质诱导抗核抗体生成及肾损伤

系统性红斑狼疮 (SLE )的病因和诱导抗核抗体 (ANA )生成的激发原迄今不明。本实验试图用ConA活化淋巴细胞的染色质免疫同系BALB/c小鼠 ,寻找诱导ANA生成的真正免疫原 ,阐明SLE发生的激发原是自身活化细胞的核成分 ,而且证明它所诱导的ANA具有致病性。从ConA活化的脾细胞中提取染色质 ,然后免疫同系BALB/c小鼠 ,用ELISA方法测定IgG类抗双链DNA (dsDNA )、抗组蛋白抗体 ,用免疫荧光法检测抗核抗体核型和免疫复合物沉积 ,用免疫印迹法测定抗核抗体谱 ,在光镜下检测肾损伤及电镜下检测肾小球沉积物 ,用考马斯亮蓝法检测尿蛋白含量。结果显示 ,活性染色质能诱导IgG类抗dsDNA、抗组蛋白等多种抗核抗体生成 ,且肾小球有显著免疫复合物沉积和蛋白尿形成。该实验表明 ,活化淋巴细胞的染色质是诱导SLE发生的真正自身免疫原。     

SAP基因注射干预小鼠SLE样综合征的发生

目的：研究SAP基因注射对SLE发病的干预作用，并进一步探讨SAP发挥作用的可能机制。方法：通过RT-PCR方法克隆SAP基因，构建其真核表达质粒pcDNA3-SAP，观察SAP基因注射对活化淋巴细胞免疫诱导小鼠产生的SLE样综合征的干预作用，以ELISA方法检测抗dsDNA抗体的产生情况，以免疫荧光法检测肾脏免疫复合物沉积；通过巨噬细胞吞噬实验观察SAP与DNA结合后对DNA清除的影响；用增殖实验检测巨噬细胞吞噬SAP结合的DNA后对预致敏淋巴细胞活化的影响。结果：SAP基因注射可有效干预小鼠SLE样综合征的发生，SAP与活化淋巴细胞DNA结合后可明显促进巨噬细胞对DNA的吞噬，并且巨噬细胞吞噬SAP结合的DNA后不引起预致敏淋巴细胞的增殖。结论：提示SAP通过促进DNA等自身抗原的有效清除干预SLE疾病的发生。     

苯甲酸雌二醇对BALB/c小鼠系统性红斑狼疮模型诱导的影响

目的：探讨不同剂量的苯甲酸雌二醇（Estradiol benzoate）对BALB/c小鼠系统性红斑狼疮（Systemic lupusery-thematosus，SLE）模型诱导的影响。方法：BALB/c小鼠卵巢摘除后用同系小鼠ConA活化的脾细胞（5×107）免疫3次，同时肌注不同剂量苯甲酸雌二醇，6周后以ELISA法检测血清抗核抗体（ANA）、抗组蛋白抗体（AHA）及血清和肾组织匀浆雌二醇（Estradiol，E2）水平，H.E、PAS染色观察肾脏病理改变，透射电镜检查肾脏超微结构的改变，直接荧光法检查IgG类免疫复合物的沉积。结果：经同系小鼠ConA活化的脾细胞免疫的BALB/c小鼠均发生红斑狼疮样改变，但不同剂量苯甲酸雌二醇组小鼠的自身抗体的产生及肾脏病理损害差异显著（P〈0.05）。结论：机体不同的雌二醇水平与SLE的病变程度相关。     

活性染色质同系免疫诱发系统性红斑狼疮样综合征

抗核抗体 (ＡＮＡ)是ＳＬＥ发病学的至关重要的自身抗体。活化淋巴细胞染色质同系免疫能诱导哪些ＡＮＡ生成以及能否引起ＳＬＥ样综合征的发生是十分受关注的方面。我们从ＣｏｎＡ活化ＢＡＬＢ/Ｃ小鼠脾细胞中分离出染色质 ,进行同系免疫 ,检测抗核抗体种类和免疫鼠肾脏病理变化。一、抗核抗体种类用ＥＬＩＳＡ法检测活性染色质诱导ＩｇＧ类抗ｄｓＤＮＡ和抗组蛋白抗体生成 ,用间接免疫荧光法检测ＡＮＡ核型。 1 用ＥＬＩＳＡ法检测ＡＮＡ :只有活性染色质组可检测到ＩｇＧ类抗ｄｓＤＮＡ抗体和抗组蛋白抗体 ,而非活性组阴性 ;2 用间接Ｆ…     

慢性粘膜免疫应答诱导的小鼠自身免疫综合征

空弯菌(CJ-S131)慢性感染小鼠具有SLE样自身免疫综合征。本文进一步用甲醛化空弯菌(CJ-S131菌苗)经口免疫BALB/c小鼠,每周两次,持续14周.模拟慢性感染时的慢性肠道粘膜免疫应答.发现免疫小鼠也具有SLE样自身免疫综合征,且较该菌慢性感染小鼠更显著。主要表现有:(1)全身免疫系统的淋巴组织显著增生;(2)B淋巴细胞多克隆激活;(3)多种自身抗体(包括抗ds-DNA.ss-DNA和组蛋白抗体)显著升高;(4)免疫复合物性肾小球肾炎;(5)多器官性(如肝、肠等组织)慢性炎症;(6)血管炎和血管周围炎。在体外自身免疫应答诱导实验中,免疫小鼠的脾细胞培养上清中,免疫球蛋白(总Ig)和抗DNA抗体显著高于非免疫小鼠。上述结果证实.空肠弯菌慢性感染所致的自身免疫综合征.和该菌抗原诱导的慢性肠道粘膜免疫应答有关。本实验为研究感染和自身免疫的关系提供了实用的动物模型。     

肿瘤细胞组蛋白的免疫原性研究

为了寻找肿瘤患者血清中多种抗核抗体 (antinuclearantibodies,ANA )生成的新的可能免疫原 ;进一步论证细胞活化是核抗原性发生改变并诱导抗体产生的根本因素。提取SP2 / 0瘤细胞组蛋白免疫同系BALB/c小鼠 ,用ELISA方法检测IgG类抗组蛋白、抗dsDNA抗体 ,免疫荧光法检测ANA核型 ,免疫印迹法测定可溶性核抗原 (ENA )抗体。结果 :SP2 / 0瘤细胞组蛋白诱导同系BALB/c小鼠产生了IgG类抗组蛋白、抗dsDNA、抗Sm、抗SS A/SS B等多种自身ANA ,其核型有周边型、均质型、颗粒型等。推测肿瘤细胞组蛋白是诱导ANA生成的免疫原之一。     

用SP2/0瘤细胞核或DNA免疫同系小鼠诱导抗核抗体的产生

用SP2 / 0瘤细胞核或DNA分别免疫Balb/c小鼠均可获得IgG抗dsDNA、抗组蛋白、抗Sm、抗SS A/SS B等抗核抗体 ,类似于ConA活化的淋巴细胞的DNA免疫 ,而正常Balb/c小鼠的DNA不能诱导出抗核抗体。实验表明肿瘤细胞的DNA类似于活化细胞的DNA具有免疫原性 ,且能表位扩展到其他核成分     

磷酸化对组蛋白免疫原性的影响

为了研究细胞活化后组蛋白磷酸化程度的改变以及对其免疫原性的影响。将正常淋巴细胞组蛋白人为加磷酸、活性组蛋白人为去磷酸 ,用Westernblot法检测其磷酸化程度 ;然后用以上不同组蛋白同系免疫BALB/c小鼠 ,用ELISA法测定IgG类抗组蛋白抗体、抗dsDNA抗体 ,用免疫荧光法检测抗核抗体核型及肾脏病理 ,用免疫印迹法测定可溶性核抗原抗体。结果发现淋巴细胞活化后 ,其组蛋白H1成分发生明显的丝氨酸磷酸化 ,对正常组蛋白人为加磷酸仍无免疫原性 ,活性组蛋白人为去磷酸后仅影响抗体产生的滴度 ,仍具有免疫原性。所以丝氨酸磷酸化在组蛋白的免疫原性改变方面起一定的作用 ,但不是主要因素     

T细胞接种对SLE样小鼠防治作用的探讨

本文在空肠弯曲菌（CJ-S131）免疫诱导的小鬼SLE样综合征模型上,观察了T细胞接种（T CellVaccination,TCV）的预防和治疗作用。用于 TCV的细胞为 CJ-S131预致敏的同系小鼠 T细胞。结果显示TCV可明显地抑制CJ-S131诱导的特异性迟发型超敏反应,相反却显著地增强抗dsDNA抗体和抗外膜蛋白抗体生成。因此TCV对SLE样小鼠没有预防及治疗作用。本文对此现象进行了讨论。     

不同凋亡水平T细胞来源的ALD-DNA对抗双链DNA抗体产生的影响

研究不同凋亡水平T细胞来源的ALD-DNA(activated lymphocyte-derived DNA)对抗双链DNA抗体产生的影响。用尼龙毛柱法分离小鼠脾脏T细胞,分别提取不同凋亡水平T细胞的DNA定义为未凋亡ALD-DNA、低凋亡水平ALD-DNA、中凋亡水平ALD-DNA和高凋亡水平ALD-DNA,并免疫同系BALB/c小鼠;用ELISA方法检测血清中IgG类抗双链DNA抗体的水平及其亚型;用考马斯亮蓝法检测免疫小鼠尿蛋白的含量。结果显示,ALD-DNA的凋亡水平与其诱导产生的抗双链DNA抗体水平成正相关,二者的相关系数r=0.852;不同凋亡水平的ALD-DNA诱导的抗双链DNA抗体均以IgG1为主,但IgG2a和IgG2b的水平在高凋亡ALD-DNA免疫组有明显增高;低凋亡ALD-DNA、中凋亡ALD-DNA和高凋亡ALD-DNA免疫小鼠均有显著蛋白尿形成,并且高凋亡ALD-DNA免疫组的尿蛋白含量有明显增高。该结果表明,高凋亡水平的ALD-DNA免疫同系小鼠更易诱导高水平的致病性IgG类抗双链DNA抗体产生,凋亡DNA可能在系统性红斑狼疮(SLE)发生发展过程中发挥了重要作用,这为我们能更加深入的理解SLE的发生机制提供了有力的实验依据。     

Immunization of nonautoimmune mice with DNA binding domains of the largest subunit of RNA polymerase I results in production of anti-dsDNA and anti-Sm/RNP antibodies

Antibodies against the N-terminal (NT) but not the basic domain (BD), DNA binding regions of the largest subunit (S1) of RNA polymerase I (RNAPI) were detected in the sera of MRL-lpr/lpr lupus mice. Antibodies against both RNAPI(S1)-NT and -BD, as well as other systemic lupus erythematosus (SLE) autoantigens (La, ribosomal P proteins and Sm/RNP) were produced by rabbits immunized with anti-DNA antibodies that had been affinity purified from SLE patients. Immunization of nonautoimmune mice (Balb/c) with RNAPI(S1)-NT, RNAPI(S1)-BD, or La in the form of GST fusion proteins, induced production of anti-double-stranded (ds) DNA and anti-Sm/RNP. GST-P1 did not induce an anti-dsDNA response in these mice. These results demonstrate that RNAPI(S1)-NT, RNAPI(S1)-BD and La can participate in an anti-autoantigen/anti-DNA antibody loop during an SLE-like autoimmune response.     

Concomitant early appearance of anti-ribonucleoprotein and anti-nucleosome antibodies in lupus prone mice

OBJECTIVE: To gain insights on initial stages of the autoimmune response in lupus prone mice taking advantage of new sensitive and quantitative techniques for the detection of autoantibodies specific for RNA- (ribonucleoproteins) and DNA-protein (chromatin) complexes. METHODS: DNA and nucleosome antibodies were detected by ELISA, antibodies to SmB, U1A-RNP, Ro52, Ro60 and La by a new radioligand assay, using de novo synthesized radio-labeled antigens. RESULTS: Analysis of anti-chromatin (including anti-nucleosome, anti-dsDNA and anti-histone antibodies) and of anti-snRNP antibodies (including anti-U1A-RNP, anti-SmB, anti-Ro52, anti-Ro60, anti-La antibodies) was performed in sequential sera from B/W, MRL+/+, MRL Yaa and MRL lpr/lpr mice. In a cohort of 105 MRL+/+ mice of different ages, 59, 51, and 57 mice were positive for anti-nucleosome, anti-SmB and anti-U1A-RNP, respectively. None of them was positive for anti-dsDNA. Importantly, antibody positivities were not randomly distributed but were significantly clustered in individual mice. Appearance of DNA- and RNA-protein complex antibodies started at approximately 18-20 weeks of age, preceding that of the anti-dsDNA (or anti-histone) antibodies that only started at 30-32 weeks. Anti-nucleosome, anti-SmB and anti-U1A-RNP antibody responses did not display any cross-reactivity as demonstrated by inhibition and adsorption experiments. CONCLUSION: These data indicate that anti-nucleosome and anti-snRNP antibodies appear early and concomitantly in lupus prone mice even though they do not share any cross-reactivity. These results fit with the assumption that their production is triggered by tightly physically associated nucleosomes and snRNP autoantigens contained in the same apoptotic bodies.     

Induction of anti-DNA antibodies in preautoimmune NZBxNZW F1 mice by immunization with a DNA-DNase I complex

Recent studies suggest that anti-DNA antibodies may arise from the immune response to a complex of DNA and a DNA-binding protein. One of the protein targets frequently recognized by anti-DNA antibodies is the enzyme DNase I. To investigate the possible role of DNase I in the induction of anti-DNA antibodies, we immunized preautoimmune NZBxNZW F1 mice with a complex of DNA and DNase I emulsified in complete Freund's adjuvant. Control mice received DNA or DNase in adjuvant. IgG anti-dsDNA antibodies were induced in 50% of the mice immunized with DNA-DNase, in 25% of the mice immunized with DNase and in 6% of the mice immunized with DNA. However, immunized mice that produced anti-DNA antibodies did not develop renal disease. These data show that a DNA-binding protein like DNase may act as carrier in the immune response that leads to anti-DNA antibodies production in an autoimmune strain, but the induced anti-dsDNA antibodies have a low pathogenic potential.     

The pentapeptide PLNPK inhibits systemic lupus erythematosus-associated renal damage

Objective

This study aimed to observe the therapeutic effect of pentapeptide PLNPK on systemic lupus erythematosus (SLE) in mice, and to study the inhibitory effect of PLNPK on activation of T cells in vivo.

Methods

Murine SLE-like chronic graft-versus-host disease (cGVHD) was induced. After treatment with PLNPK (100, 200, 400 μg/kg per day) for 70 days, serum blood urea nitrogen, creatine, total cholesterol, triglyeride and albumin were tested, and serum levels of anti-dsDNA and anti-histone antibodies were detected by ELISA. The pathological damage and IgG deposition in the kidney were identified. Concanavalin A (ConA)-induced T lymphocyte proliferation in SLE mice was also tested.

Results

PLNPK can reduce serum blood urea nitrogen, creatine, total cholesterol, triglyeride, and elevate serum albumin, and reduce levels of anti-dsDNA and anti-histone antibodies in the murine SLE model. Pathological damage and IgG deposition in the kidney were reduced in the PLNPK-treated group. PLNPK inhibited T lymphocyte infiltration in kidney tissues and ConA-induced T lymphocyte proliferation in SLE mice.

Conclusion

Our results demonstrate that PLNPK can suppress T cell function and reduce the production of autoantibodies, and may be a feasible and effective therapy in the SLE model.     

Cross-recognition between histones and La/SSB may account for anti-DNA reactivity in SLE patients

Antibodies to La/SSB are detected in sera of patients with primary Sjogren's syndrome (pSS) and systemic lupus erythematosus (SLE). The vast majority of anti-La/SSB positive sera contain antibodies directed towards a linear B-cell epitope of La/SSB spanning the sequence 349-364aa (pep349-364). The aim of this study was to evaluate the fluctuation of antibody levels to major B-cell epitopes of La/SSB over time and investigate for their possible crossreactions. Sequential sera from 15 SLE and 15 pSS patients, followed from 3 to 10 years were obtained. All patients with SLE were positive for anti-Ro/SSA, anti-La/SSB and anti-dsDNA antibodies and patients with pSS were positive for anti-Ro/SSA and anti-La/SSB antibodies. Sera from 30 patients with SLE without anti-La/SSB antibodies and 30 healthy individuals served as disease and negative control respectivelly. All sera tested for the presence of anti-pep349-364 antibodies, using a specific ELISA. Specific anti-pep349-364 IgG was purified from sera of SLE patients and evaluated for cross reactivity against dsDNA and histones. In all SLE sera the levels of anti-pep349-364 antibodies varied in time and fluctuated in parallel with anti dsDNA antibodies. Anti-pep349-364 IgG purified from 7 SLE patients. Five out of 7 were found to react with calf thymus DNA in ELISA. All purified (7/7) anti-pep349-364 IgG preparations reacted with histone H1 and failed to produce a positive immunofluorescence pattern in Crithidia luciliae anti-dsDNA assay which lacks histones. Competative inhibition experiments demonstrated that histone H1 could inhibit completely the binding of anti-pep349-364 IgG to pep349-364 while pep349-364 inhibited by 70% the binding of anti-pep349-364 IgG to histone H1. These findings indicate that a subgroup of SLE patients possess cross-reacting anti-histone H1 antibodies and anti-pep349-364 antibodies, which can be faulty considered as anti-dsDNA reactivity in regular ELISA techniques.     

Antigen specificity of anti-nuclear antibodies complexed to nucleosomes determines glomerular basement membrane binding in vivo

Monoclonal anti-nuclear antibodies which are complexed to nucleosomes are able to bind to the glomerular basement membrane (GBM) in vivo, whereas purified antibodies do not bind. The positively charged histone moieties in the nucleosome are responsible for the binding to anionic determinants in the GBM. We tested the hypothesis that the specificity of the autoantibodies complexed to the nucleosome influences the glomerular binding of the antibody-nucleosome complex. We induced the formation of these immune complexes in vivo, by intraperitoneal inoculation of hybridomas producing monoclonal anti-nuclear antibodies (four anti-histone, three anti-double stranded (ds)DNA and three anti-nucleosome antibodies) into nude BALB/c mice. In ascites and plasma from the mice inoculated with these hybridomas, nucleosome/autoantibody complexes were detected in comparable amounts. Immunofluorescence of kidney sections revealed that about 60% of the mice inoculated with anti-nucleosome or anti-dsDNA hybridomas had immunoglobulin deposits in the GBM, whereas only 15% of the mice with anti-histone hybridomas showed these deposits (p ≦ 0.04). In the Matrigel^®-ELISA (used as a GBM surrogate) ascites from anti-nucleosome or anti-DNA hybridomas displayed significantly higher titers (p ≦ 0.002) than ascites from anti-histone hybridomas. In conclusion, nucleosome/immunoglobulin complexes comprising anti-nucleosome or anti-dsDNA auto-antibodies do bind more frequently to the GBM in vivo than nucleosome/immunoglobulin complexes containing anti-histone antibodies. It therefore appears that the specificity of the antibody bound to the nucleosome is a critical determinant for the nephritogenic potential of the nucleosome-autoantibody complex.     

A peptide DNA surrogate that binds and inhibits anti-dsDNA antibodies

Autoantibodies to dsDNA are an important diagnostic marker and pathogenic factor for systemic lupus erythematosus (SLE). Although the anti-dsDNA antibodies present in SLE are indicative of an antigen-driven response, the antigen has not been conclusively identified. The specific SLE anti-dsDNA antibodies were obtained by affinity purification using a dsDNA-coupled Sepharose column. Using the anti-dsDNA antibodies to screen a phage peptide display library, we demonstrated that purified polyclonal anti-dsDNA antibodies and a monoclonal anti-dsDNA antibody specifically bind a 15 mer peptide ASPVTARVLWKASHV. This chemically synthesized peptide could be recognized by anti-dsDNA antibodies in ELISA and Dot blot. This 15 mer peptide can inhibit anti-dsDNA antibodies binding to dsDNA antigen in immunoassays and in the Crithidia luciliae assay while a control peptide did not inhibit anti-dsDNA antibodies. This study demonstrates the potential usefulness of the peptide DNA surrogate in diagnostic tests of SLE and in the investigation of the origin of anti-dsDNA antibodies. It may also be used in studies of the DNA-anti-DNA antibody interaction.