用异质培养生产单克隆抗体

单克隆抗体(mABs)的生产不仅费用昂贵,而且需要特殊的组织培养设备和技能。在体外,培养杂交瘤细胞需要添加胎牛血清(FCS)以确保生长,然而胎牛血清中含有的转铁蛋白和白蛋白会污染收获的单克隆抗体上清。因此下游纯化技术要确保将污染蛋白去除,这样不仅费时、收率低,而且需要特殊设备。粗糙的纯化过程会使单克隆抗体受损或变性。     

人血液血管细胞生成素的胎肝免疫印记检测

目的：制备一种新蛋白——人血液血管细胞生成素（hemangiopoietin,HAPO）的单克隆抗体,检测其在胎肝中的表达。方法：杂交瘤方法制备抗HAP0的单克隆抗体;非竞争酶联免疫吸附实验测定抗体的相对亲和力;蛋白G亲和层析纯化腹水中的抗体,免疫印记方法检测胎肝中天然HAPO的表达：结果：所获单抗分别为IgG1及IgM,其轻链均为κ。三株IgG1亚类单抗的相对亲和力分别为3．06×10^9mol／L,6．07×10^8mol／L和1．71×10^10 mol／L。亲和纯化后抗体的纯度达99％以上：胎肝中在蛋白水平上可以检测到HAP0的表达,天然HAPO的分子量接近于重组HAPO的分子量。结论：人胚胎肝组织中在蛋白水平上可以检测到HAPO的表达.     

用去掉免疫球蛋白IgG的腹水提高体外培养的单克隆抗体产量(英文)

发展了一种在实验室大幅度提高抗体产量的方法,即采用添加2%的去免疫球蛋白IgG的腹水于无血清培养基中的方法,培养杂交瘤细胞,获得了高达3.55 ×10⁶/ml的细胞密度,纯化后获得了135μg/ml的单克隆抗体产量,比通常的用无血清培养的单位体积培养液抗体产量高4倍。对于体外生产单克隆抗体而言,这种方法经济并且易于推广,它的成功是抗体产量提高的一个巨大进步。     

抗牛血清IgG单克隆抗体杂交瘤细胞株的建立及鉴定

用牛血清IgG免疫BALB/c小鼠,取其脾细胞与小鼠骨髓瘤细胞SP2/0进行融合,用含山羊血清的培养基培养细胞,上清用间接ELISA法筛选。获得4株能稳定分泌抗牛血清IgG的单克隆抗体杂交瘤细胞株,分别命名为1G5、2A8、3F5、4C5。其中2A8为IgG2a,其余3株为IgG1;腹水单抗的ELISA滴度均超过10-5;除3F5株单抗与山羊血清有交叉反应外,1G5、2A8、4C5株与人、马、猪、羊、兔、豚鼠等血清均不发生交叉反应;4株单抗与制备病毒性疫苗的基质液呈阴性反应;4株单抗识别分子量为160kD的牛血清IgG的两个不同抗原表位;4株单抗相对亲和力大小依次为4C5>2A8>1G5>3F5,相对敏感度依次为2A8>4C5>3F5>1G5;4株杂交瘤细胞株的染色体计数均大于90条,连续培养三个月以及冷冻保存半年后复苏,细胞生长良好。使用这些单抗建立的双抗体夹心法检测生物制品中的残留牛血清IgG。     

抗牛生长激素单克隆抗体及其免疫亲和吸附柱的制备

我们用杂交瘤技术获得了分秘抗牛生长激素单克隆抗体的细胞系(4B-2)。接种此细胞于小鼠所产生腹水的抗体含量达10mg／ml。经免疫亲和层析方法纯化的单克隆抗体,属1BG1型。将单克隆抗体偶联到Sepharose 4B上,创成了免疫亲和吸附柱,可以从牛垂体匀浆中一步纯化牛生长激素。偶联有50mg单克隆抗体的亲和柱一次可结合3mg牛生长激素。经单克隆抗体亲和层析纯化的牛生长激豢,保持了与兔肝细胞膜受体结合的能力,及在去垂体大白鼠中促进胫骨生长板生长的功能。     

在中空纤维细胞培养系统内用无血清培养基生产单克隆抗体

用1640SFM无血清培养基在VF－2中空纤维细胞培养系统内培养7E8杂交瘤细胞,最大活细胞密度为2．34×10⁶／ml,该活细胞密度分别是转瓶培养和静态瓶培养结果的3．7倍和2．2倍。培养42天共收获7E8细胞培养液10000ml,其单克隆抗体(简称单抗)的ELIsA效价为1:20000左右,该效价是转瓶培养和静态瓶培养结果的25倍。ID。0mI培养液经50％饱和硫酸铵盐析和sephadex G-200柱层析提纯,获纯化单抗IgG 51．82mg。该系统平均每天生产单抗12．3mg。研究结果表明;在中空纤维培养系统内用无血清培养基培养杂交瘤细胞的方法可望用于体外大规模生产单抗。     

人突触小体相关蛋白25单克隆抗体的制备及初步鉴定

目的:制备抗人突触小体相关蛋白25(SNAP25)的鼠源单克隆抗体。方法:利用大肠杆菌表达SNAP25蛋白,纯化后免疫BALB/c小鼠制备杂交瘤细胞,筛选针对SNAP25的阳性杂交瘤细胞株,鉴定抗体亚型;用杂交瘤细胞株制备腹水单抗,纯化后利用SDS-PAGE检测抗体纯度。结果:表达并纯化得到纯度大于90%的SNAP25蛋白,免疫小鼠后经2轮筛选得到12株阳性杂交瘤细胞株,其中抗体重链包括IgG1、IgG2型,轻链大部分为κ链;选择具有相对较高抗原结合活性的14号杂交瘤细胞株制备腹水,纯化后得到纯度大于90%的抗体。结论:获得1株高纯度的针对SNAP25的鼠源单克隆抗体,为肉毒毒素的检测奠定了基础。     

用国产单克隆抗体纯化重组干扰素α1b的研究

制备高纯度的重组干扰素α1b的关键技术是单克隆抗体亲和层析。我们过去用英国Celltech公司提供的抗干扰素α单克姓抗体珠进行纯化。为适应大规模生产的需要,我们用安科生物高科技公司所建的杂交瘤细胞分泌的干扰素单克隆抗体及其制备的抗体珠进行纯化,获得较好的结果,纯化IFNα1原液纯度（SDS－PAGE,HPLC,比活）,鼠IgG及单克姓抗体珠的吸附量,使用次数等均符合要求,并用于大规模生产。     

牛IFN-γ原核表达、单克隆抗体制备及其ELISA检测方法的建立

实验旨在建立牛重组IFN-γ(BovIFN-γ)的ELISA检测技术,为牛传染病的免疫学诊断提供新方法。PHA刺激体外培养的奶牛外周血白细胞,从培养细胞中提取总RNA,经过RT-PCR扩增出BovIFN-γ基因cDNA,进一步克隆至pET28a,转化大肠杆菌,经IPTG诱导,表达出预期大小(18kD左右)组氨酸标记蛋白,经鉴定为BovIFN-γ;以纯化的重组BovIFN-γ为免疫原,应用淋巴细胞杂交瘤技术,获得4株能稳定分泌抗BovIFN-γ单克隆抗体的细胞株,分别命名为A7、A10、G6与G10。免疫球蛋白亚类鉴定证明杂交瘤细胞所分泌的抗体均为IgG1,腹水效价在1∶210×100~1∶211×100之间。Western-blot分析显示,4株单抗均能特异性结合重组BovIFN-γ。ELISA试验表明,4株单抗只与融合蛋白BovIFN-γ反应,而不与非相关性蛋白Ag85B、ESAT-6-CFP-10、GM-CSF等发生反应。选取A10细胞株分泌的单克隆抗体、纯化的多克隆抗体及辣根过氧化物酶(HRP)标记的羊抗兔IgG,建立了检测BovIFN-γ的双抗体夹心ELISA方法。实验结果表明,此方法检测敏感性达到2ng/mL,特异性良好,为进一步建立灵敏、特异的病原感染诊断方法奠定了基础。     

牛血清白蛋白单克隆抗体杂交瘤细胞株的建立及鉴定

用牛血清白蛋白(BSA)免疫BALB/c小鼠,取其脾细胞与小鼠骨髓瘤细胞SP2/0进行融合,培养上清经过双抗体夹心法检测初步筛选分泌鼠IgG的杂交瘤细胞,将此种杂交瘤细胞注射小鼠产生的腹水用间接ELISA法筛选,获得4株能稳定分泌抗BSA单克隆抗体的杂交瘤细胞株,分别命名为2A5、3A3、3G6、4A8。鉴定结果显示,2A5细胞分泌IgG2a/κ,其余3株细胞分泌IgG1/κ;纯化后4株腹水单抗的纯度达90%以上,对BSA的ELISA滴度均可达到1∶100000以上;4株单抗均不与人以及马、猪、羊、兔、豚鼠等血清发生交叉反应;W estern B lotting试验证明4株单抗均识别分子量为68000的BSA;用间接ELISA法测定4株单抗相对亲和力及相对敏感度大小依次为3A3>2A5>3G6>4A8;杂交瘤细胞株连续培养3个月以及冻存半年后复苏,细胞生长良好,杂交瘤细胞分泌的抗体效价稳定。     

Hybridoma cultures using porcine serum not containing immunoglobulin and dialysis fractions

The whole swine serum was treated with ammonium sulphate to precipitate immunoglobulins. The remained IgG was removed with the use of protein A-sepharose. The hybridoma cells producing monoclonal antibodies to lambda phage (class IgG) were cultured in Dalbecco's modified Eagle medium with addition of a 5% whole swine serum or of a treated unwhole one (final concentration of the protein being 3 mg/ml). Upon these conditions, hybridoma cells had similar growth rate and population density (1-1.3 X 10(6) cells/ml). Maximal antibody concentration was almost similar (80-90 mcg/ml). Purity of a sample of monoclonal antibodies isolated by the method of chromatography with the use of protein A-sepharose from supernatant containing the unwhole serum was no less than 99%, whereas it was considerably lower (12-15%) in the case of the whole serum.     

Hybridoma cell growth and anti-neuroblastoma monoclonal antibody production in spinner flasks using a protein-free medium with microcarriers

The main disadvantages of foetal calf serum as the world-wide common serum supplement for cell growth are its content of various proteins of variable concentrations between batches as well as its high cost. The use of serum-free and protein-free media is gradually becoming one of the goals of cell culture especially for standardizing culture conditions or for simple purification of cell products like monoclonal antibodies. The mouse hybridoma cells 14/2/1 were cultivated either in protein-free UltraDOMA medium or in serum-containing RPMI medium with and without microcarriers to generate high quantities of monoclonal antibodies against neuroblastoma tumour cells. Cell growth rate, IgG production, viability, glucose and lactate concentrations, attachment rate and doubling time have been used as investigation criteria. Modifications of culture procedures (static or stirred), inoculum density, and microcarrier concentration caused an improvement of monoclonal antibody production. The kinetics of antibody synthesis was best in spinner culture with 2 ml of microcarriers in protein-free medium. These results of short-term microcarrier culture in stirred spinner flasks indicate that IgG yields in protein-free medium 2.5-fold higher to those in serum-supplemented medium can be achieved.     

Changes in monoclonal antibody productivity of recombinant BHK cells immobilized in collagen gel particles

Animal cell perfusion high density culture is often adopted for the production of biologicals in industry. In high density culture sometimes the productivity of biologicals has been found to be enhanced. Especially in immobilized animal cell culture, significant increase in the productivity has been reported. We have found that the specific monoclonal antibody (MAb) productivity of an immobilized hybridoma cell is enhanced more than double. Several examples of enhancing productivities have been also shown by collagen immobilized cells. Immobilized cells involve some different points from non-immobilized cells in high density culture: In immobilized culture, some cells are contacted together, resulting in locally much higher cell concentration more than 10⁸ cells/ml. Information originating from a cell can be easily transduced to the others in immobilized culture because the distance between cells is much nearer. Here we have performed collagen gel immobilized culture of recombinant BHK cells which produce a human IgG monoclonal antibody in a protein-free medium for more than three months. In this high density culture a stabilized monoclonal antibody production was found with around 8 times higher specific monoclonal antibody productivity compared with that in a batch serum containing culture. No higher MAb productivity was observed using a conditioned medium which was obtained from the high density culture, indicating that no components secreted from the immobilized cells work for enhancing monoclonal antibody production. The MAb productivity by the non-immobilized cells obtained by dissolving collagen using a collagenase gradually decreased and returned to the original level in the batch culture using a fresh medium. This suggests that the direct contact of the cells or a very close distance between the cells has something to do with the enhancement of the MAb productivity, and the higher productivity is kept for a while in each cell after they are drawn apart.     

Monoclonal antibody production in hollow fiber bioreactors using serum-free medium

Murine hybridoma cells that produce monoclonal antibody directed against human fibronectin have been cultured in VITAFIBER II and VITAFIBER V hollow fiber bioreactors using defined, serum-free WRC 935 medium. During a two-week growth period, following inoculation of the bioreactors, the cells proliferated to an extent where the bioreactor was filled with cultured cells. Using a 5 sq. ft. VITAFIBER V bioreactor, over 15 grams of antibody were produced during the 40 days of the experiment. This antibody was greater than 95% IgG. During the production period, this packed mass of cells produced 579 +/- 15 mg IgG per day. Because the medium is formulated for air equilibration and high cell densities, WRC 935 medium is especially useful for production of gram quantities of monoclonal antibodies using continuous feed hollow fiber bioreactor cell culture systems.     

人IL17-RD胞外区真核表达及其单克隆抗体的制备

为了进一步研究白介素17受体D (IL-17RD) 在IL-17信号的调节作用,探索是否可以通过单克隆抗体阻断IL-17RD介导的IL-17信号通路而缓解自身免疫疾病,利用昆虫表达载体从Sf9细胞中表达纯化人IL-17RD-ECD蛋白,免疫Balb/C小鼠30 d,取小鼠脾脏细胞并与小鼠骨髓瘤细胞SP2/0进行融合,应用有限稀释法进行筛选,经过克隆化后筛选到一株能稳定分泌抗IL-17RD-ECD的杂交瘤细胞株1F8。经过初步鉴定,该细胞株分泌的抗体类型为IgG1+kappa类,经过Western blot     

A new serum-free medium for monoclonal antibody production

A new serum-free, defined-protein, medium for the growth of murine hybridoma cells and the production of monoclonal antibodies has been developed. Designated WRC 935 medium, this formulation supports the growth of hybridoma cells in higher numbers, and promotes better cell viabilities and increased monoclonal antibody levels compared to growth in DMEM supplemented with 10% fetal bovine serum or in a DMEM/F-12 serum-free mixture. In suspension cultures, WRC 935 medium typically promoted cell growth to densities over two million cells per milliliter. This medium also promoted the rapid growth of cells following their transfer from liquid nitrogen storage. WRC 935 medium is especially useful for high density cell culture production methods using hollow-fiber bioreactors. Hollow-fiber bioreactors using this medium produced antibody at an average rate of 11 mg/day, and the antibody concentration ranged from 10 to 40 mg/ml.     

Influence of antibody isotype on passive serotherapy of lymphoma

We assessed the in vivo anti-tumor effectiveness of monoclonal antibodies of different isotypes. Starting with a hybridoma cell secreting an IgG3 anti-Thy-1.1 antibody, we isolated three variant hybridoma cell lines secreting anti-Thy-1.1 antibody of the IgG1, IgG2a, and IgG2b isotypes. Each antibody displayed identical antigen binding properties, but differed in their ability to mediate in vitro lysis of Thy-1.1+ AKR/J SL2 lymphoma cells. In assays of complement dependent cytotoxicity, the relative activity of each antibody isotype was IgG2a = IgG2b greater than IgG3 greater than IgG1. In assays of antibody-dependent cell-mediated cytotoxicity when using non-immune spleen cells as effectors, the relative activities were IgG2a greater than or equal to IgG2b greater than IgG1 greater than IgG3. Infusion of equivalent amounts of each antibody (1.5 mg) in AKR/Cum (Thy-1.2+) mice inoculated subcutaneously with 3 X 10(5) AKR/J SL2 lymphoma cells resulted in significant inhibition of tumor growth only in mice treated with IgG2a antibody. However, the antibodies were cleared at different rates, with the IgG2a antibody having the slowest clearance. When antibody doses were adjusted to achieve equivalent serum levels 24 hr after infusion, all of the antibody isotypes exhibited at least some anti-tumor activity, although IgG2a antibody was again the most effective. These studies demonstrate that the difference in anti-tumor activity between antibodies of different isotypes may result from differences both in their serum clearance rate and their ability to interact with host effector mechanisms.     

A human hybrid hybridoma

Hybrid hybridomas are obtained by fusion of two cells, each producing its own antibody. Several authors have reported the construction of murine hybrid hybridomas with the aim to obtain bispecific monoclonal antibodies. We have investigated, in a model system, the feasibility of constructing a human hybrid hybridoma. We fused two monoclonal cell lines: an ouabain-sensitive and azaserine/hypoxanthine-resistant Epstein-Barr virus-transformed human cell line that produces an IgG1 kappa antibody directed against tetanus toxoid and an azaserine/hypoxanthine-sensitive and ouabain-resistant human-mouse xenohybrid cell line that produces a human IgG1 lambda antibody directed against hepatitis-B surface antigen. Hybrid hybridoma cells were selected in culture medium containing azaserine/hypoxanthine and ouabain. The hybrid nature of the secreted antibodies was analyzed by means of two antigen-specific immunoassays. Our results show that it is possible, with the combined use of transformation and xenohybridization techniques, to construct human hybrid hybridomas that produce bispecific antibodies.     

抗人B7-H1单克隆抗体的制备和鉴定

目的:采用杂交瘤技术制备抗人B7-H1单克隆抗体,并对其进行鉴定。方法:经抗原免疫的小鼠脾细胞与小鼠骨髓瘤细胞以常规方法融合;用间接ELISA法筛选分泌抗体的杂交瘤细胞株;阳性克隆用有限稀释法获得稳定分泌抗人B7-H1单克隆抗体的杂交瘤细胞株;扩增杂交瘤细胞注射进小鼠腹腔后制备腹水;纯化腹水中的单克隆抗体并对其亚型进行鉴定;用间接ELISA法测抗体效价;将肺癌组织制成石蜡切片,用抗人B7-H1抗体进行免疫组化染色。结果:获得1株稳定分泌抗人B7-H1单克隆抗体的杂交瘤细胞株,所分泌的单抗类型为IgG1;抗体效价为1×108,纯化后的抗体含量为6.76g/L;免疫组化实验中,单抗可与肺癌组织表面的B7-H1蛋白特异地结合。结论:制备了人B7-H1单克隆抗体,为B7-H1检测试剂盒的研制奠定了基础。     

Manipulation of heterogeneous hybridoma cultures for overproduction of monoclonal antibodies.

In searching for ways to manipulate heterogeneous hybridoma cell cultures (ATCC HB124) to obtain increased production of monoclonal antibodies (IgG2a), we have selected for a higher secreting but slower growing subpopulation using the level of fluorescent surface-associated antibodies and a fluorescence-activated cell sorter. Cell surface fluorescence was found to be correlated with specific antibody secretion rate over the short term but not with intracellular antibody content. Also, the specific secretion rate of a heterogeneous population of hybridoma cells grown in batch culture has been shown to be inversely correlated with an increase in either the initial cell concentration or the medium antibody concentration. Several experiments suggest that an upper limit exists for medium antibody concentration, above which antibody is degraded at the same rate at which it is produced. Should other cell lines behave similarly, strategies for overproduction of monoclonal antibodies suggested herein could be profitably used in industry.