基于基因免疫制备抗人绒毛膜促性腺激素β亚基单克隆抗体及其特性研究

用真核表达人绒毛膜促性腺激素β亚基((human chorionic gonadotrophinβ,hCGβ)的重组质TR421-hCGβ免疫BALB/c小鼠,采用B淋巴细胞杂交瘤技术进行细胞融合,ELISA法筛选阳性细胞株,经过多次的克隆化培养,最终获得10株持续、稳定分泌抗hCGβ单克隆抗体的杂交瘤细胞株。随机抽取6H1杂交瘤细胞进行抗体的制备、纯化及免疫学特性的分析。间接ELISA法证明6H1单抗属于IgG2a亚类。Western blot证明6H1单克隆抗体可以特异性结合hCGβ,间接免疫荧光和流式细胞仪等结果表明,6H1单克隆抗体能够不同程度的结合不同来源的肿瘤细胞膜上表达的hCGβ分子,为进一步研究其生物学功能奠定了物质基础。     

DNA免疫法制备抗人Flt3-ligand单克隆抗体及其鉴定

Ｆｌｔ3 ｌｉｇａｎｄ(ＦＬ)是近几年新发现的一种相对分子质量 (Ｍｒ)为 30 0 0 0的糖蛋白 ,其中有Ｍｒ 为 120 0 0的糖类〔1,2〕,主要参与体内的造血调控。在体外培养体系中 ,Ｆｌｔ3 ｌｉｇａｎｄ可与ＩＬ 3,ＩＬ 6,ＳＣＦ及ＧＭ ＣＳＦ等细胞因子协同 ,刺激造血干 /祖细胞增殖 ,并能协同诱导造血干 /祖细胞分化为树突状细胞等 ,因而在造血干 /祖细胞的体外培养中获得广泛应用〔1,3〕。ＤＮＡ免疫法是一种新的制备单克隆抗体(ｍＡｂ)的免疫方法 ,它不需要制备大量抗原 ,只需将编码抗原的ｃＤＮＡ克隆到真核表达载体上 ,用重组质粒对动物…     

脾内免疫法制备抗α2-抗纤溶酶单克隆抗体

α2抗纤溶酶(α2Ａｎｔｉｐｌａｓｍｉｎ,α2ＡＰ)是由肝脏合成分泌的,含有452个氨基酸的单链糖蛋白,分子量为70000。α2ＡＰ属于丝氨酸酶抑制物家族成员之一,在人血浆中α2ＡＰ是主要的纤溶酶抑制物,在控制纤溶中起关键作用[1]。为此制备α2ＡＰ单克隆抗体,建立ＥＬＩＳ?..     

抗肌红蛋白单克隆抗体的制备与鉴定及其初步应用

目的 制备和鉴定抗肌红蛋白(Mb)单克隆抗体,为人肌红蛋白检测试剂的研制奠定基础.方法 用人肌红蛋白抗原免疫BALB/c小鼠,采用杂交瘤技术进行细胞融合,用ELISA方法筛选,有限稀释法进行克隆化培养阳性杂交瘤细胞株.ELISA法测定小鼠腹水滴度,CLIA法对抗体进行配对实验与特异性鉴定.结果 筛选培养出9株分泌抗肌红蛋白单克隆抗体的杂交瘤细胞株,腹水滴度为1∶5×104 ～ 1∶2×105.通过配对实验,有5株抗体6种组合可以成功配对.这5株抗体的亲和常数为6.46×108 ～ 3.68×109 L/mol.用5株抗体所建立的6种化学免疫分析方法与人Hb交叉反应率为7.434×103％ ～2.904×10-2％,与人ALB交叉反应率为4.980×10-7％ ～3.830×10-5％.用Mb17B6与Mb21E8两株抗体建立的CLIA标准曲线的线性系数为0.997,灵敏度为6.02ng/mL.结论 成功制备了可以应用于免疫分析的抗肌红蛋白单克隆抗体.     

抗人NGF单克隆抗体的制备及初步鉴定

神经营养因子（　ｎｅｕｒｏｔｒｏｐｈｉｃ　ｆａｃｔｏｒｓ，　ＮＴＦｓ）是一类对中枢和外周神经系统均有营养活性的蛋白质，其主要功能是促进神经系统的发育，保护并修复受损神经元，以及促进生长和增进认知记忆过程中神经元之间的连结［］。神经生长因子（ｎｅｒｖｅ　ｇｒｏｗｔｈ　ｆａｃｔｏｒ，　ＮＧＦ）是发现最早、研究最多的一种ＮＴＦ。制备抗ＮＧＦ单克隆抗体（ｍＡｂ）可为研究其在体内组织中表达及分布提供一种工具，并可为基因工程制备ＮＧＦ提供检测方法。我们受澳大利亚Ｆｌｉｎｄｅｒ大学周兴福教授委托，研究制备了分…     

抗人CA50单克隆抗体的制备、鉴定及其应用

目的制备抗人糖抗原50(CA50)单克隆抗体(m Ab),鉴定其免疫学特性并建立化学发光免疫分析法检测体系。方法将人CA50抗原免疫BALB/c小鼠,利用杂交瘤技术进行细胞融合,筛选后得到稳定分泌抗CA50抗体的杂交瘤细胞株。经细胞扩大培养及纯化获得m Ab后,建立化学发光免疫分析法检测体系,并对其线性范围、准确度、灵敏度、重复性进行评估,同时进行血样的测定。结果筛选出4株抗人CA50的杂交瘤细胞株,效价均在1∶108以上,2株配对抗体不与CA125、CA153、CA199、CA724交叉。建立的化学发光免疫分析法检测范围为0~500 U/m L,回收率为107.08%,灵敏度为0.83 U/m L,重复性CV值10%,与参比试剂检测血样的结果比较符合率为96.7%,Kappa值为0.911。结论成功制备了抗人CA50m Ab,建立了人CA50的化学发光免疫分析法检测体系。     

抗人LSECtin单克隆抗体的制备与初步鉴定

目的:制备抗肝脏、淋巴结窦内皮细胞C型凝集素(LSECtin)单克隆抗体(mAb),并进行特性鉴定。方法:采用原核表达的LSECtin免疫BALB/c小鼠,以间接ELISA法筛选分泌特异性mAb的杂交瘤细胞,采用蛋白印迹、间接免疫荧光、流式细胞术和免疫组化染色法鉴定mAb的特异性。结果:共获得8株可稳定分泌mAb的杂交瘤细胞株。mAb的Ig亚类均为IgG,效价达1∶106~1∶107。这些mAb均可识别转染3T3细胞膜上的人LSECtin,6株mAb可特异识别肝脏窦内皮细胞。结论:成功地制备8株抗LSECtin的mAb,经免疫印迹、流式细胞术和免疫组化染色检测,这些mAb的特异性良好,为研究LSECtin的功能提供了有力的试剂。     

抗人滋养细胞单克隆抗体的制备及其免疫生物学特性鉴定

研制抗人滋养细胞单克隆抗体并分析其免疫生物学特性。方法采用滋养细胞免疫Ｂａｌｂ／ｃ小鼠;用细胞ＥＬＩＳＡ法鉴定ｍＡｂ的特异性;用补体依赖的溶细胞作用测定ｍＡｂ的细胞毒性。结论利用细胞免疫法所获该组ｍＡｂ所针对的抗原表位,可能是诱发免疫性流产的滋养细胞膜特异性抗原。     

抗人CD100单克隆抗体的制备与初步鉴定

目的：研制可识别天然CD100分子的单克隆抗体（mAb)。方法：采用真核表达的CD100分子免疫BALB/c小鼠，以间接ELISA法筛选阳性杂交瘤，并分别用人急性T淋巴细胞性白血病细胞系MOLT-4，猿T淋巴细胞系MLA-144及猴EB病毒转化的B淋巴细胞系（BLCL），进行间接免疫荧光染色和流式细胞术鉴定mAb的特异性。结果：共获得7株可稳定分泌mAb的杂交瘤细胞株。所有mAb均可识别人和猴细胞系的膜表面天然CD100分子，其中6株可识别猿细胞系膜表面的天然CD100分子，结论：成功地制备了7株抗CD100分子的特异性mAb。为研究人和猿，猴CD100分子的结构与功能提供了新的手段。     

Production of anti-dengue NS1 monoclonal antibodies by DNA immunization

Monoclonal antibodies against dengue NS1 protein were generated following immunization of mice with plasmid DNA encoding the transmembrane form of NS1 from dengue serotype 2 virus. A mammalian expression vector, pDisplay, was engineered to direct cell surface expression of dengue NS1 and tested for transient expression in COS cells. Two mice were immunized intramuscularly with six doses of 100 microg of plasmid at 2-week intervals; one mouse received a booster of live virus prior to the last plasmid injection. Both mice showed antibody responses against dengue antigens in dot enzyme immunoassay. Following fusion, hybridomas were screened with dot enzyme immunoassay against all four dengue serotypes. Specificity to the NS1 protein was confirmed by western blot analysis. Among five anti-dengue NS1 monoclonal antibodies generated, two clones were serotype 2 specific, two clones reacted with all four serotypes and the last also reacted with Japanese encephalitis virus. Reactivity against native or denatured forms of NS1 revealed three clones with reactivity to linear epitopes and two clones recognizing conformational epitopes. Such diverse specificity of anti-dengue NS1 monoclonal antibodies indicates that DNA immunization, especially with the combination of virus boosting, is an efficient way of producing monoclonal antibodies against viral protein. This has opened up a possibility of producing monoclonal antibodies to rare viral proteins that are difficult to isolate or purify.     

Specificity of two anti-human albumin monoclonal antibodies

We have studied the reaction of two monoclonal anti-human albumin antibodies with various fragments of albumin comprising the entire molecule. Using solid phase assay, inhibition of enzyme immunoassay and of passive hemagglutination, they were shown to be specific for a fragment F1, of 6000 dalton, located near the C terminus of human albumin. In addition, these antibodies reacted weakly with fragment D which corresponds to the N terminal half of the molecule.     

Production and characterization of monoclonal antibodies to anti-human chorionic somatomammotropin by immunization with two free synthetic peptides

The peptides corresponding to the fragments 135-140 and 166-174 of human chorionic somatomammotropin (hCS) were synthesized, and used to raise monoclonal antibodies to the native hCS molecule. The synthetic peptides were injected into BALB/c mice in the free form, i.e. not conjugated to a carrier, and the spleens were fused with Sp2/01Ag8 myeloma line to produce monoclonal antibodies. The antibodies produced belonged to the IgM and IgG classes and, once purified by affinity chromatography on hCS-Sepharose, they were covalently coupled to macroporous polystyrene beads and characterized by competitive radioimmunoassay. Their affinity constants were determined by elaborating the radioimmunoassay data by nonlinear regression analysis and they were found to range from 10(5) to 10(6) M-1. The evaluation of the affinity constant of the antibodies produced is always important as a measure of the immunogenicity of an antigen, particularly when synthetic peptides are used as immunogens.     

抗人PD-L1 单克隆抗体的制备及其应用

目的:获得能应用于临床诊断以及阻断PD-L1 与PD-1 结合的抗人PD-L1 单克隆抗体。方法:采用重组表达的人PD-L1 蛋白免疫BALB/ c 小鼠,通过杂交瘤细胞融合技术获得稳定分泌抗人PD-L1 单抗的阳性细胞株,ELISA 方法鉴定抗体的特异性、亲和力、亚型等方面特性;免疫印迹、间接免疫荧光方法对肿瘤细胞进行检测;肿瘤杀伤实验验证抗体阻断活性。结果:共获得2 株抗人PD-L1 单抗,抗体效价分别为1 2.56 106 和1 3 105 ,亲和力分别为1.5 109 L/ mol 和2.5 108 L/ mol,均与PD-L2 蛋白无交叉反应。免疫印迹、间接免疫荧光证实抗体有诊断作用。杀伤实验显示抗体有阻断作用。结论:共获得两株稳定分泌高效价、高特异性的抗人PD-L1 单抗的杂交瘤细胞株,能作为诊断抗体应用于肿瘤表型检测和预后有效性的评估。抗体的阻断功能可应用于联合CIK 细胞免疫治疗。     

Effect of anti-human sperm monoclonal antibodies on mouse in vitro fertilization

We employed anti-human sperm monoclonal antibodies to investigate how sperm membrane antigens are involved in gamete interactions. We have produced seven monoclonal antibodies specific for human sperm antigens, that showed reaction with mouse sperm by ELISA and by immunofluorescence. These antibodies did not react with zona pellucida or any other somatic human tissue. Some degree of toxicity was detected for oocytes at high antibody concentration and this was correlated with their inhibitory effect on fertilization. Unrelated to the degree of antigen expression or localization on sperm membrane, the antibodies showed several degrees of inhibition. The participation in sperm-zona pellucida interaction for every antigen could be evidenced by the impaired penetration of sperm caused by the presence of several concentrations of antibody. Thus, DAN-2, MOU-8 and VAC-4 inhibit mouse in vitro fertilization.     

鼠抗人B7-H4单克隆抗体的制备及其生物学特性鉴定

目的:研制鼠抗人B7-H4分子的单克隆抗体(mAb)并鉴定其生物学特性。方法:以高表达人B7-H4分子的转基因细胞L929/B7-H4为免疫原,常规免疫BALB/c小鼠,采用B淋巴瘤杂交技术,经免疫荧光标记和流式细胞术分析、反复筛选、多次克隆化培养,获得两株可特异分泌鼠抗人B7-H4分子mAb的杂交瘤细胞株。采用快速定性试纸分析法鉴定mAb所属的Ig亚类。用Dot-blot、Western blot鉴定mAb的特异性,竞争结合抑制实验鉴定mAb所识别的抗原结合位点,T细胞增殖抑制阻断实验对mAb的生物学功能进行初步的鉴定。结果:获得两株持续、稳定地分泌抗B7-H4 mAb的杂交瘤细胞,分别命名为1F10和2B2。Dot-blot的结果显示,两株mAb均能特异性识别B7-H4分子。Westernblot检测显示,mAb 2B2可以特异性识别B7-H4分子,而mAb 1F10则不能识别。位点竞争实验表明,两株mAb之间,mAb 1F10与商品化的mAb H74之间识别位点不同,mAb 2B2与商品化mAb识别位点相近。T细胞增殖抑制阻断试验显示,这两株mAb均能一定程度地阻断B7-H4对T细胞的抑制作用。结论:成功地获得两株抗人B7-H4分子的mAb,为进一步研究B7-H4分子的生物学功能提供了有效的工具。     

Idiotypic analysis of five xenogeneic antisera to anti-human thyroglobulin monoclonal antibodies

Five xenogeneic anti-idiotypic antisera (anti-id) were produced against individual BALB/c-derived monoclonal antibodies (mAb) which bound to different peptidic determinants on the human thyroglobulin molecule (Tg). Idiotypic analysis performed using sensitive radioimmunoassays revealed that: (1) the anti-id highly precipitated their homologous ligands; (2) two anti-id displayed minor cross-reactivities with one or two heterologous mAb; (3) each unlabelled homologous mAb was able to inhibit the idiotype binding of the corresponding anti-id; (4) no significant inhibition of homologous idiotype binding was observed with large excess of heterologous mAb; (5) efficient inhibition of mAb binding to Tg was observed only when homologous anti-id served as inhibitor. The data support the conclusion that xenogeneic anti-id may detect on their corresponding ligands individual idiotypic specificities that can be located at the mAb-combining site. Such reagents may constitute appropriate probes for further studies on anti-Tg autoimmunity.     

Identification of epitopes recognized by a panel of six anti-human IgG2 monoclonal antibodies.

Human IgG2 contains several subclass specific amino acid residues or deletions in the CH1 and CH2 domains and also in the hinge region. These substituted residues are the structural correlates for IgG2 specific epitopes. Since human IgG2 has different biological properties from other subclasses, some IgG2 epitopes may be located in regions correlating with sites determining the biological functions. Previously, we produced three anti-IgG2 monoclonal antibodies (mAbs) with highly specific and interesting reactivities using improved immunization protocols. However, it has been almost impossible to identify epitopes conventionally, because human IgG2 is so resistant to proteolysis that various proteolytic fragments could not be isolated. In this study, we identified the epitopes recognized by anti-IgG2 mAbs by SDS-PAGE, Western blotting, amino acid sequence analysis and peptide/mAb binding ELISA, thus overcoming the need for fragment isolation. A panel of six anti-human IgG2 mAbs, including the current WHO/IUIS specificity standards (HP6002, HP6008, HP6014) and our own (HG2-6A, HG2-30F, HG2-56F), reacted with distinct epitopes. The residues essential to expression of the epitopes recognized by the mAbs were: Pro234, Val235 and Val309 for HG2-56F, HG2-30F and HP6008, respectively. HP6014 reacted with the epitope expressed by Thr214 and its neighboring residues. HG2-6A was reactive with the hinge region, and HP6002 was assumed to be directed against discontinuous epitopes requiring intact Fc for expression. Through these studies, the pepsin and papain cleavage sites of human IgG2 were also clarified.     

Production and characterization of monoclonal antibodies against DNA single ring diamines adducts

The synthetic conjugate of the genotoxic compound 2,4 diaminotoluene (2,4 DAT) with gelatin (2,4 DAT-GEL) was employed to elicit specific antibodies directed against a restricted class of aromatic diamines. Using this immunogen, mouse monoclonal antibodies (MAbs) have been produced. These MAbs have been characterized and used in ELISA to detect 2,4 DAT covalently linked to biopolymers. The MAbs could bind to different synthetic 2,4 DAT-biopolymer adducts as well as to DNA from rats treated in vivo with the aromatic diamine, but they did not react with gelatin or biopolymers alone. The use of these MAbs has been investigated in order to develop a highly sensitive test to detect adducts of this genotoxic compound with nuclear DNA.     

New monoclonal anti-human Fc gamma receptor II antibodies induced platelet aggregation

We developed two new monoclonal antibodies, designated NNKY3-2 and NNKY4-7, that recognized a 40-kD platelet protein. They appeared to be monoclonal anti-Fc gamma receptor II (Fc gamma RII) antibodies from the results of flow cytometric binding inhibition studies using another monoclonal anti-Fc gamma RII antibody (2E1). The addition of NNKY3-2 or NNKY4-7 to platelet-rich plasma (PRP) led to a typical aggregation pattern preceded by a lag phase, but their addition to washed platelets did not induce aggregation. The aggregation of PRP by these antibodies was inhibited by prostaglandin E1 (PGE1) or staurosporine (protein kinase C inhibitor), whereas it was only slightly affected by a monoclonal anti-GPIIb/IIIa antibody or Arg-Gly-Asp-Ser. Furthermore, these antibodies induced the aggregation of washed platelets plus normal serum, but not that of washed platelets plus heat-treated serum (destruction of complement activity). These results suggest that NNKY3-2 or NNKY4-7-induced aggregation involves an unusual pathway independent of fibrinogen, and that the important factor is the participation of complement. NNKY3-2 and NNKY4-7 may be useful to study the relationship between autoantibodies, the Fc receptor, and complement in idiopathic thrombocytopenic purpura.