间接ELISA法用于细胞抗原特异的单克隆抗体筛选

在单克隆抗体（ｍＡｂ）制备过程中，间接ＥＬＩＳＡ方法用于可溶性蛋白为抗原的ｍＡｂ筛选。当得不到可溶性抗原的情况下，用细胞膜抗原或克隆抗原分子，再以痘苗病毒为载体转入真核细胞制备ｍＡｂ，可以用间接免疫荧光法进行筛选。由于此种方法费时，所需细胞数量大，影...     

抗人白细胞单克隆抗体的特异性及其特性鉴定

目的制备抗人白细胞单克隆抗体（ｍＡｂ），并对其识别抗原及组织的特异性进行鉴定。方法采用分离的人全白细胞悬液免疫Ｂａｌｂ／ｃ小鼠，取脾细胞与Ｓｐ２／０细胞常规融合，用间接ＥＬＩＳＡ筛选ｍＡｂ，流式细胞仪及免疫组化染色ＳＰ法鉴定其组织特异性。　结果成功地制备１株抗人白细胞　ｍＡｂ，命名为ＳＺ－１０５。ＥＬＩＳＡ法测定其腹水效价为１×１０－５。琼脂糖双扩散鉴定为ＩｇＧ１类。流式细胞仪间接免疫荧光技术及免疫组化ＳＰ法测定表明，ｍＡｂ　ＳＺ－１０５可选择性地与外周血液的粒细胞、单核细胞和淋巴细胞呈强阳性反应，而与红细胞及血小板不出现反应。该ｍＡｂ还可与正常人骨髓的白细胞前体起反应。另外，在肝、肺、脾、胸腺及淋巴结正常组织中的巨噬细胞表面，也有ＳＺ－１０５抗原表达。ＳＺ－１０５抗原经亲和层析纯化，再经ＳＤＳ－ＰＡＧＥ　和Ｗｅｓｔｅｒｎ　ｂｌｏｔ证实，ｍＡｂ　ＳＺ－１０５识别的抗原是相对分子质量（Ｍｒ）为７５　０００左右的单链蛋白多肽。结论　获得１株具有高度免疫学活性和组织特异性的抗人白细胞ｍＡｂ　ＳＺ－１０５，其对研究白细胞的分化、免疫功能，以及隐匿性急、慢性炎症疾病的放免显像诊断都具有一定的临床意义。     

抗人肝癌单克隆抗体HCD78的制备及免疫组化定位

原发性肝癌是世界上最常见的恶性肿瘤之一，具有发病隐袭、病死率高的特点，早期诊断对预后的意义重大。单克隆抗体（ｍＡｂ）技术问世后，人们试图通过应用抗肝癌ｍＡｂ提高肝癌的早期诊断率。然而目前获得的抗肝癌ｍＡｂ识别的抗原都不是肝癌特异性抗原，而且由于肿瘤异质性的存在，又使其临床应用受到一定影响。本研究应用自建的人肝癌细胞株ＨＣ１０８免疫小鼠，制备了１株能稳定分泌抗人肝癌ｍＡｂ的杂交瘤细胞。免疫组化证实，该ｍＡｂ具有较好的特异性，其识别的肿瘤抗原主要定位于细胞膜。现将建株过程和初步鉴定的结果报道如下：１…     

抗人Fas单克隆抗体的制备及鉴定

Ｆａｓ／Ａｐｏ１／ＣＤ９５抗原的发现,始于对两株单克隆抗体（ｍＡｂ）的功能观察,即抗Ａｐｏ１ｍＡｂ和抗ＦａｓｍＡｂ〔１,２〕。由于二者都能识别细胞膜上ＣＤ９５蛋白抗原,且能诱导敏感细胞凋亡,才导致今天对Ｆａｓ抗原的生物医学研究。制备抗ＦａｓｍＡｂ对于Ｆａｓ抗原的深入研究,尤其是对Ｆａｓ抗原信号传导机制的阐明,以及生物医学应用都有重要的意义。本文利用Ｆａｓ＋的细胞作为免疫原,制备了１株鼠抗人ＦａｓｍＡｂ２Ａ１。１材料和方法１．１材料１．１．１细胞系Ｓｐ２／０小鼠骨髓瘤细胞、Ｊｕｒｋａｔ人Ｔ淋巴…     

抗胃癌单克隆抗体识别的噬菌体呈现肽与天然抗原的关系

噬菌体呈现的随机肽库已成功地用于筛选Ｂ细胞或Ｔ细胞表位。为进一步研究胃癌相关抗原与相应单克隆抗体（ｍＡｂ）结合的结构基序及其相互作用,我所通过两株胃癌ｍＡｂＭＧ７和ＭＧｂ２筛选噬菌体呈现的随机九肽库,获得一些可与ｍＡｂ结合的噬菌体呈现肽。我们采用竞争抑制实验,研究了这些肽与天然胃癌相关抗原的关系。１材料和方法１．１材料胃癌ｍＡｂＭＧ７和ＭＧｂ２由本所研制〔１,２〕,通过筛选噬菌体呈现的随机九肽库〔３,４〕,获得可与相应ｍＡｂ结合的噬菌体呈现肽〔５,６〕。１．２方法１．２．１噬菌体呈现肽竞争抑制试验将纯…     

CD226在猴睾丸分布的免疫组织化学研究

１９８５年, Ｂｕｒｎｓ等［１］以活化的 Ｔ细胞为免疫原,制备了抗活化Ｔ细胞表面抗原的单克隆抗体（ｍＡｂ）,并将其中 １株ｍＡｂ Ｌｅｏ－Ａ１识别的抗原命名为人Ｔ细胞谱系特异性活化抗原 １（Ｔ ｌｉｎ－ｅａｇｅ－ｓｐｅｃｉｆｉｃ ａｃｔｉｖａｔｉｏｎ ａｎｔｉｇｅｎ１, ＴＬｉＳＡ１）。 ｍＡｂＬｅｏ－Ａ１在混合淋巴细胞反应中,可抑制细胞毒Ｔ细胞（ｃｙｔｏｔｏｘｉｃ Ｔ ｌｙｍｐｈｏｃｙｔｅｓ, ＣＴＬ）分化。随后Ｓｃｏｔｔ等［２］发现, ＴＬｉＳＡ１也高表达于血小板表面,可刺激血小板的活化和凝集,遂将此抗原…     

三株肝癌单克隆抗体的Western免疫印迹实验

Ａ１０、Ｅ５和Ｆ１１是３株抗人肝细胞癌的单克隆抗体（ｍＡｂ）。经ＡＢＣ免疫组化染色法证实，这些ｍＡｂ针对的抗原在８例肝癌组织中呈高表达，Ａ１０、Ｅ５和Ｆ１１分别为６／８，５／８和６／８；而在肝炎中呈低表达，分别为２／１１、０／１１和１／１１［１］。故这几株ｍＡｂ所针对的相应抗原可能是肝癌相关抗原。作为筛选肝癌细胞表达文库的候选抗体，通过Ｗｅｓｔｅｒｎ免疫印迹反应可了解其相应抗原的一些性质及确定ｍＡｂ对变性抗原的识别能力。１　材料和方法１－１　细胞株和ｍＡｂ　肝癌细胞株ＳＭＭＣ７７２１与ＨＨＣＣ…     

抗B-CLL Id x抗CD3双特异性抗体的制备及其特性研究

应用无筛选标记细胞株杂交瘤·杂交瘤细胞直接融合法制备了２株分泌抗慢性Ｂ淋巴细胞白血病（Ｂ－ＣＬＬ）Ｉｄｘ抗ＣＤ３双特异性抗体（ＢｓＡｂ）的四价体瘤细胞株。采用间接ＥＬＩＳＡ试验与间接免疫荧光试验证明了该ＢｓＡｂ能分别与Ｂ－ＣＬＬ患者血清及带ＣＤ３标记的细胞特异性结合,经细胞结合试验证明该ＢｓＡｂ同时具备与Ｉｄ及ＣＤ３两种抗原结合能力,经酶桥联法证明该ＢｓＡｂ亚类为ＩｇＧ１×ＩｇＧ２ａ,用ＭＴＴ法证实ＢｓＡｂ能诱导Ｔ细胞活化增殖     

抗bFGF单克隆抗体的鉴定及其意义

用重组牛ｂＦＧＦ免疫Ｂａｌｂ／ｃ小鼠，通过细胞融合，以反向间接血凝和间接ＥＬＩＳＡ筛选，以及有限稀释法克隆化，建立了９株稳定分泌抗ｂＦＧＦ单克隆抗体（ｍＡｂ）杂交瘤细胞。对其中３株用Ｗｅｓｔｅｒｎｂｌｏｔ和生物活性抗体中和实验进行了鉴定。结果显示，ｍＡｂ可结合重组牛或人ｂＦＧＦ，并能抑制ｂＦＧＦ刺激Ｂａｌｂ／ｃ３Ｔ３细胞的生长；腹水的ＥＬＩＳＡ滴度为１∶３０００；用其中２株ｍＡｂ建立的双抗体夹心ＥＬＩＳＡ法灵敏度可达５０ｐｇ／孔。本文还讨论了抗ｂＦＧＦｍＡｂ的应用价值。     

鼻咽癌抗独特型抗体诱导的体液和细胞免疫应答

目的 探讨抗独特抗体２Ｈ４和５Ｄ３模拟抗原诱导免疫应答的能力。方法 用Ａｂ２免疫Ｂａｌｂ／ｃ小鼠获得抗血清,以ＥＬＩＳＡ检测其Ａｂ３,Ｗｅｓｔｅｒｎ Ｂｌｏｔ分析其识别抗原的分子质量。用迟发型超敏反应（ＤＴＨ）和淋巴细胞增殖试验,检测Ａｂ２诱发细胞免疫反应的能力。结果 ２Ｈ４,５Ｄ３免疫同系动物产生的含有抗抗蚀特型抗体（Ａｂ３）的抗血清,可特异性地与靶细胞结合。ＦＣ２（Ａｂｌ）和经２Ｈ４免疫的Ａｂ     

Addition of an extra immunoglobulin domain to two anti-rodent TNF monoclonal antibodies substantially increased their potency

The functional valency of a monoclonal antibody (mAb) has important influences on such things as antigen avidity, Fc-mediated immune effector functions, and clearance of immune complexes. cV1q, a neutralizing rat/mouse chimeric anti-mouse tumor necrosis factor (TNF) monoclonal antibody (mAb), and Rt108, a neutralizing mouse anti-rat TNF (anti-raTNF) mAb, appear to be functionally monovalent for TNF-binding despite containing two antigen binding sites. The functional monovalency of these two independent anti-rodent TNF mAbs is presumably a result of steric hindrance from one TNF molecule binding to one Fab arm that prevents binding of a second TNF molecule to the other Fab arm. To test whether this steric hindrance could be overcome by introducing extra space and flexibility between the Fab arms, these mAbs were engineered to contain an extra CH1 immunoglobulin domain between the CH1 and hinge domains of their heavy chains. In vitro binding data showed that, compared to the original mAbs, the modified mAbs (S-mAbs) had greater capability of binding two TNF molecules simultaneously. In vitro activity assays showed that, compared to the original mAbs, the S-mAbs had significantly greater TNF-neutralization potency, with the S-mAb version of cV1q (S-cV1q) being 200-fold more effective at blocking mouse TNF (muTNF) and the S-mAb version of Rt108 (S-Rt108) being 20-fold more effective at blocking raTNF. Similar results were observed in vivo, where S-cV1q was between 100- and 500-fold more protective than cV1q in mice challenged with endotoxin. These data reveal that introduction of another constant region immunoglobulin domain into two unrelated mAbs dramatically enhanced their neutralization potency. Other mAbs may also show more potent activity using this engineering approach, particularly mAbs that recognize homopolymeric antigens.     

Generation of monoclonal antibodies to coelomocytes of the purple sea urchin Arbacia punctulata: characterization and phenotyping

Cellular cytotoxicity is a key component of animal innate immune responses that is one of the first lines of defense against invaders. There is increasing interest in the study of the cellular immune response, particularly non-specific cytotoxic cells and natural killer cells and their receptors. Studies of non-specific cytotoxic cell and natural killer cell recognition and killing (and the receptors involved) will reveal new and important insights into cellular mechanisms of host defense. Here we describe mAbs specific for coelomocyte sub-populations of the purple sea urchin, Arbacia punctulata, using highly purified coelomocyte populations as the antigen source. Monoclonal antibodies were selected using flow cytometric screening methods. Several of the mAbs were shown to bind to two sub-types of coelomocytes when assayed by fluorescence microscopy. Furthermore, these mAbs inhibited coelomocyte cytotoxicity against vertebrate target cells in a functional assay. The mAbs have been used in immunoprecipitation studies.     

Human T-cell leukemia-associated cell surface glycoprotein GP37: studies with three monoclonal antibodies and a rabbit antiserum

Three monoclonal antibodies (mAbs), termed SN2, SN2a and SN2b, were used in the present work to study a human T-cell leukemia-associated cell surface glycoprotein, GP37. Strong specificity of mAbs SN2, SN2a and SN2b for T leukemia cells was demonstrated by radioimmunoassay and fluorescence-activated cell sorter (FACS) analysis. GP37 was not detected on normal human peripheral blood lymphocytes, purified normal T-cells, normal thymocytes nor normal bone marrow cells. Furthermore, GP37 was barely detectable on phytohemagglutinin (PHA)- and Concanavalin A (Con A)-activated T-cells. The results indicate clinical utility of these mAbs. Competitive binding experiments show that the epitopes recognized by SN2 and SN2a are sufficiently close to each other to allow complete reciprocal inhibition of binding whereas the epitopes recognized by SN2 and SN2b are less close to allow only partial reciprocal binding inhibition. The biochemical nature of antigenic determinants defined by these mAbs was studied by treating T leukemia cells with trypsin, chymotrypsin, thermolysin, neuraminidase and mixed glycosidases. The results suggest that the antigenic determinants defined by these mAbs all consist of the protein moiety of the glycoprotein GP37. No significant antigenic modulation was observed when T leukemia cells were reacted with SN2. In a sequential immunoprecipitation experiment, a 125I-labeled leukemia antigen preparation was first treated with a rabbit anti-T leukemia antiserum. The latter had been prepared by immunizing a rabbit with a partially purified human T leukemia antigen preparation and showed a good specificity for T leukemia cells. Subsequent treatment of the labeled antigen preparation with SN2 showed that SN2 antigen had been precleared. Thus, both mouse mAb SN2 and the rabbit anti-T leukemia antiserum react with the same GP37 molecule.     

CD147 monoclonal antibodies induce homotypic cell aggregation of monocytic cell line U937 via LFA-1/ICAM-1 pathway

CD147 is a 50 000-60 000 MW glycoprotein of the immunoglobulin superfamily broadly expressed on haemopoietic cell lines and peripheral blood cells. In the present study, six monoclonal antibodies (mAbs) directed against the CD147 protein were generated. The antigen defined by the generated CD147 mAbs is widely expressed on haemopoietic cell lines, peripheral blood cells and is a lymphocyte activation-associated cell surface molecule. The generated CD147 mAbs precipitated a broad protein band from U937 cells of 45 000-65 000 MW under reducing conditions. Functional analysis indicated that the CD147 mAbs markedly induced homotypic cell aggregation of U937 cells, but not K562 cells. The CD147 mAb-induced cell aggregation was inhibited by leucocyte function-antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) mAbs. However, the expression of LFA-1 and ICAM-1 molecules on U937 was not altered by CD147 mAb treatment. The U937 cell aggregation induced by CD147 mAb was also inhibited by ethylenediamine tetra-acetic acid (EDTA), sodium azide and when incubated at 4 degrees. We therefore propose that the binding of CD147 mAb to CD147 molecule, which mimics the natural ligand binding, may generate intracellular signals that activate LFA-1/ICAM-1 intercellular adhesion pathway.     

抗HIV-1核心抗原p24单克隆抗体的制备及特性的初步鉴定

目的 :建立分泌抗HIV 1p2 4单克隆抗体 (mAb)的杂交瘤细胞株 ,并对其特性进行初步鉴定。方法 :以纯化的基因工程制备的p2 4抗原免疫BALB/c小鼠 ,取免疫小鼠的脾细胞与Sp2 /0骨髓瘤细胞融合 ,经HAT、HT选择培养及有限稀释法进行克隆化后 ,用间接ELISA法及Dotblot对其进行筛选和特性鉴定。结果 :筛选到 2株可分泌抗HIV 1p2 4mAb的杂交瘤细胞 ,其腹水效价为 1×10 -5,亲和力为 1.7× 10 4～ 1.8×10 4mol/L ,mAb的Ig亚类均为IgG1。两株mAb与HBcAg、HCVRNA阳性血清及HIVgp4 1等均无交叉反应 ,只与HIV 1p2 4抗原阳性血清产生特异反应。结论 :成功地建立了 2株可分泌抗HIV 1p2 4mAb的杂交瘤细胞 ,为进一步研制HIV 1p2 4抗原的ELISA检测试剂盒奠定了基础     

FINE ANALYSIS OF RECOGNITION SITES OF MONOCLONAL ANTIBODIES, 1B7 AND 1E4, USING L CELL TRANSFECTANTS OF RECOMBINANT MOUSE MHC CLASS II GENES

Recognition sites of two monoclonal antibodies (mAbs), 1B7 and 1E4, specific for murine MHC class II were determined, using eleven L cell transfectants which express recombinant class II (I-A) molecules. 1B7 positive cells possessed a haplotype k in the α-helix of the β-chain, whereas 1E4 positive cells had haplotype b at the α-helix of the β-chain. The α-helix of the β-chains is regarded as an important site for antigen binding. Thus, the 1B7 and 1E4 mAbs may be useful for analysis of functional sites on class II molecules involved in antigen recognition.     

CD6 monoclonal antibodies differ in epitope,kinetics and mechanism of action

CD6 is a type I T‐cell surface receptor that modulates antigen receptor signalling. Its activity is regulated by binding of its membrane proximal domain (domain 3) to a cell surface ligand, CD166. CD6 monoclonal antibodies (mAbs) specific for the membrane distal domain (domain 1) perturb CD6 function including itolizumab (Alzumab?), which has reached the clinic for treatment of autoimmune disease. We characterized molecular and functional properties of several CD6 mAbs including itolizumab to define potential mechanisms of action. Epitope mapping using the crystal structure of CD6 to design mutants identified two distinct binding sites on different faces of domain 1, one containing residue R77, crucial for MT605 and T12.1 binding and the other, E63, which is crucial for itolizumab and MEM98. Analysis of binding kinetics revealed that itolizumab has a lower affinity compared with other CD6 domain 1 mAbs. We compared potential agonistic (triggering) and antagonistic (blocking) properties of CD6 mAbs in assays where the mechanism of action was well defined. CD6 domain 1 and 3 mAbs were equally effective in triggering interleukin‐2 production by a cell line expressing a chimeric antigen receptor containing the extracellular region of CD6. CD6 domain 1 mAbs hindered binding of multivalent immobilized CD166 but were inferior compared with blocking by soluble CD166 or a CD6 domain 3 mAb. Characterization of CD6 mAbs provides an insight into how their functional effects in vivo may be interpreted and their therapeutic use optimized.     

Antinucleosome autoantibodies bind directly to cell lines in vitro and via the FcgammaRIIB receptor to B lymphocytes in vivo: a role for immune complexes in interactions between antinucleosome IgG2a and B cells of BXSB lupus mice

The initial novel observation of this study was that most B cells of male BXSB lupus mice bear surface IgG2a(b) of extrinsic origin. To define the surface antigen, we here examine three (NZBxBXSB)F1-derived IgG2a(b) monoclonal antibodies (mAbs) selected for binding to cell surfaces. Surprisingly, all three mAbs bound the nucleosome (nuc) particle, the fundamental unit of chromatin and an early target of autoimmunity in systemic lupus erythematosus. Their tentative dissociation constant (K(d)) for soluble nuc particles was approximately 7 x 10(-10) m. The mAbs bound more weakly to both H2A-H2B-DNA and H3-H4-DNA complexes, and in immunoblot they stained all four core histones. The mAbs detected a surface antigen on all cell lines examined, present on viable cells. When stripped of nuc, and in the presence of DNase I, their binding to cell lines improved. Heparin displaced the antigen from the cell surface. In vivo, the three mAbs stained B cells of several BALB/c mice clearly stronger than the isotype control; this differential staining was significantly reduced in FcgammaRIIB-deficient mice. The results indicate that the three mAbs recognize (a) planted antigen on viable cultured cells and (b) soluble autoantigen in vivo, leading to immune complexes that bind to FcgammaRIIB. Further experiments demonstrated that antinuc IgG2a could be eluted from splenocytes of a male BXSB lupus mouse. Hence, at least part of the extrinsic IgG2a(b) found on BXSB B cells may represent FcgammaRIIB-bound nuc-IgG2a(b) complexes.     

Single step screening of monoclonal antibodies against interferon-gamma-induced surface molecules on human monocytes

Interferon-gamma (IFN-gamma) activation of human monocytes in vitro results in enhanced phagocytosis and cellular cytotoxicity. These enhanced effector functions are attributable, at least in part, to increased expression of recognition molecules on the plasma membrane. In this article we report a rapid screening procedure for the primary selection of monoclonal antibodies (mAbs) which bind to cell surface molecules, the expression of which is increased or decreased by IFN-gamma. The procedure is based on flow cytometric analysis of mixed cell populations. Mouse mAbs were prepared using human monocytes cultured for 40 h with 400 U/ml of IFN-gamma as the immunogen. The hybridoma supernatants were screened using mixtures of six cell populations, some of which were pretreated with IFN-gamma for 40 h. Cells included in the mixture were chosen for their distinctive light scatter profiles. mAbs of interest were identified by preferential binding to monocytes and increased or decreased binding to monocytes treated with IFN-gamma. This procedure allowed us to screen several hundred clones per day, and to immediately eliminate mAbs that bound to B cells, T cells, neutrophils, and several cell lines. We selected ten mAbs which bound to surface molecules on monocytes that were modulated by IFN-gamma. Further characterization of five of the initial ten mAbs revealed that mAb gamma M phi 22.2 and mAb gamma M phi 197.1 bind to the high affinity Fc receptor for IgG (Fc gamma RI). mAb gamma M phi 28.3 appears to bind to a class II histocompatibility antigen and mAb gamma M phi 150.3 and mAb gamma M phi 195.18 appear to have binding patterns to human leukocytes and cell lines which are distinct from previously described mAbs. This rapid and specific procedure for screening mAbs has broad application for selecting mAbs that are specific for any given cell type and/or for surface molecules that are modulated by any cytokine and other hormone.     

抗李斯特菌溶血素单克隆抗体的制备及初步鉴定

目的: 研制抗李斯特菌溶血素(LLO)的单克隆抗体(mAb).方法: 通过诱导重组大肠杆菌BL21(pGEX-6p-1-hly), 以SDS-PAGE分离菌体蛋白, 切割目的蛋白LLO-GST条带, 研磨粉碎后免疫BALB/c小鼠, 取免疫鼠脾细胞与Sp2/0细胞融合.利用亲和层析法纯化目的蛋白, 作为检测抗原进行杂交瘤细胞的筛选.采用间接ELISA法测定腹水效价, Dot-ELISA、 Western blot分析mAb的特异性.结果: 获得3株稳定分泌抗LLO mAb的杂交瘤细胞株3B6、 4D1、 5D10, 其Ig亚类均为IgG1.3B6、 4D1、 5D10腹水的ELISA效价分别为1:2×105、 1:2×105、 1∶1×105.Western blot试验中, 3株mAb均能与融合蛋白LLO-GST发生反应出现特异性条带, 而与纯化蛋白GST不反应.在Dot-ELISA试验中, 3株mAb均能与表达LLO的细菌发生特异性反应.结果表明, mAb 3B6、 4D1、 5D10是针对LLO的特异性mAb.结论: 成功地制备了抗LLO的mAb, 为进一步研究LLO的生物学特性、产单核细胞李斯特菌的致病机制, 以及建立产单核细胞李斯特菌(LM)快速检测技术奠定了基础.