Monoclonal antibody production in murine ascites. II. Production characteristics

OBJECTIVE: To characterize monoclonal antibody production parameters of five hybridoma cell lines in murine ascites for correlation with clinicopathologic changes in mice. METHODS: Five hybridoma cell lines were grown in groups of 20 mice. Fourteen days prior to inoculation with 10(6) hybridoma cells, mice were primed with 0.5 ml of pristane given intraperitoneally. Ascites fluid was collected a maximum of three times by abdominal paracentesis; volume was measured and antibody concentration was determined by ELISA for each sample. RESULTS: Trends differed among cell lines when comparing ascites volumes and antibody concentrations over time from the first to the third tap. Antibody production was greatest at tap 1 for Groups 2B11 and 2C6D9; tap 2 for Group 3C9; and tap 3 for Groups RMK and 3D6. Total antibody production ranged from 422.90 to 996.64 mg; total ascites fluid volume ranged from 74.2 to 115.7 ml; and mean antibody concentration for taps 1, 2, and 3 ranged from 2.50 to 15.03 mg/ml among cell lines. CONCLUSION: Production characteristics were significantly different among hybridoma cell lines. Determination of production characteristics of hybridomas and correlation with clinicopathologic changes in mice may be valuable in making recommendations for managing mice with ascites.     

人生长分化因子15单克隆抗体制备、鉴定及药用价值初探

目的:制备稳定分泌抗人生长分化因子15(GDF15)单克隆抗体(m Ab)的杂交瘤细胞系,并对其分泌的m Ab进行鉴定。方法:根据人GDF15氨基酸序列特征,设计合成了8条能够免疫产生GDF15特异性抗体的抗原多肽,与VLP载体偶联后,免疫雌性BALB/c小鼠,利用杂交瘤技术制备鼠源抗人GDF15的m Ab,用间接ELISA检测m Ab腹水效价。结果:获得针对7个抗原多肽的12株稳定分泌抗人GDF15的杂交瘤细胞系,腹水m Ab效价可达1×104~1×109。结论:获得了针对不同抗原多肽的抗人GDF15的特异性m Ab,为进一步研发以GDF15为靶点的单克隆抗体抗肿瘤药物奠定了基础。     

番木瓜环斑病毒单克隆抗体的制备及在病毒分型上的初步应用

本试验是用番木瓜环斑病毒(Papaya ringspot virus, PRV)提纯制剂免疫的BALB/c小白鼠脾细胞与Sp~2/o-Ag14骨髓瘤细胞融合,获得三个能稳定传代并分泌抗番木瓜环斑病毒的单克隆抗体的杂交瘤细胞系。其中23H1 McAb的效价较高,用ELISA检测,腹水抗体效价高达1:76800,能被PRV兔抗血清所阻断。这3个杂交瘤细胞系产生的单抗与TMV和CMV无血清交叉反应。它们可把PRV四个毒株初步区分为三个血清型。     

天然属性抗LDL及oxLDL IgM亚类抗体的制备与鉴定

目的：制备天然属性抗低密度脂蛋白（LDL）及抗氧化低密度脂蛋白（oxLDL）IgM亚类抗体。方法：给予Babl/c小鼠高胆固醇饮食,4周后取脾细胞直接与SP2/0细胞融合,以纯化的LDL及oxLDL为抗原,对阳性杂交瘤细胞生长孔进行间接ELISA筛选。鉴定杂交瘤上清的免疫球蛋白亚类,进而采用免疫沉淀和免疫印迹法对获得的抗体进行免疫学反应性鉴定。结果：杂交瘤细胞分泌的抗LDL及抗oxLDL的天然抗体通过ELISA法被筛选出来,可以与LDL或oxLDL发生高亲和力结合,经过4次克隆化,最终获得2株稳定分泌天然抗LDL的抗体,命名为5G8和2H7,及1株稳定抗oxLDL的抗体,命名为3A6,3株抗体均属于IgM亚类,无交叉反应,可以满足免疫印迹、免疫沉淀等实验要求。结论：成功制备了抗LDL及抗oxLDL IgM亚类抗体,为研究天然抗体在体内脂质代谢和相关心脑血管疾病如动脉粥样硬化等发生发展中的作用提供了重要的研究工具。     

Modulation of hybridoma cell growth and antibody production by coating cell culture material with extracellular matrix proteins

The influence of coating polystyrene tissue culture plates with different proteins on murine hybridoma cell growth and antibody production was investigated. Fibronectin, collagen I, bovine serum albumin and laminin were used to coat NUNC^® and COSTAR^® cell culture plates. Cell number and antibody concentration in culture fluids were quantified as indicators for cell viability, proliferation and productivity. Adhesive behaviour, morphology, expression of surface receptors of hybridoma cells and the presence of tyrosine-phosphorylated proteins in cell lysates were characterized by cell adhesion experiments, microscopy, flow cytometry and Western Blot analysis.It was shown that coatings with fibronectin (0.2 μg/ml) lead to a substantial improvement of cell growth by 50–70% and an increase of monoclonal antibody production by 100–120%.Collagen I coatings showed an improvement in cell growth by 30–70% and by 60% for the production of monoclonal antibodies. Coatings with BSA and laminin had minor effects on these parameters. It was found that the hybridoma cell lines used in this study did not express the α₂-chain of the α₂β₁-integrin, which is responsible for binding to collagen and laminin.However, the presence of β₁-integrin on the cell surface was shown, which should enable hybridoma cells to bind fibronectin. We propose, therefore, that fibronectin adsorption to cell culture materials may be a promising approach to enhance the production of monoclonal antibodies by cultivated hybridoma cells.     

Retinoic acid improves a hybridoma culture in a fructose-based medium by up-regulation of fructose incorporation via retinoid nuclear receptors

Fructose was focused on as an alternative sugar source to glucose in a hybridoma culture medium because it decreases lactate production during cultivation, leading to cell and product stability. But, not all human hybridoma cell lines grew well in a fructose-based serum-free medium. We found that the addition of all-trans-retinoic acid to the fructose-based medium improved the growth and monoclonal antibody production of hybridoma cell lines by up-regulation of fructose incorporation that represented increased expression of the fructose transporter, GLUT5. Selective activation of retinoid nuclear receptor by synthetic ligands showed that both retinoic acid receptors and retinoid X receptors might be related to the improvement of the fructose-based hybridoma culture. This study might be applicable to cell cultures susceptible to lactate and pH changes as well as hybridoma cultures.     

Retinoic Acid Improves a Hybridoma Culture in a Fructose-Based Medium by Up-Regulation of Fructose Incorporation via Retinoid Nuclear Receptors

Fructose was focused on as an alternative sugar source to glucose in a hybridoma culture medium because it decreases lactate production during cultivation, leading to cell and product stability. But, not all human hybridoma cell lines grew well in a fructose-based serum-free medium. We found that the addition of all-trans-retinoic acid to the fructose-based medium improved the growth and monoclonal antibody production of hybridoma cell lines by up-regulation of fructose incorporation that represented increased expression of the fructose transporter, GLUT5. Selective activation of retinoid nuclear receptor by synthetic ligands showed that both retinoic acid receptors and retinoid X receptors might be related to the improvement of the fructose-based hybridoma culture. This study might be applicable to cell cultures susceptible to lactate and pH changes as well as hybridoma cultures.     

抗细小病毒B19-VP2单克隆抗体的建立

制备抗细小病毒B19－VP2单克隆抗体,用于检测人血清中的B19抗原,辅助诊断相关疾病;也可用于制备人类细小病毒基因工程疫苗。用纯化的基因工程表达的B19－VP2蛋白免疫BALB/c小鼠,取免疫小鼠的脾细胞和小鼠骨髓瘤Sp2/0细胞融合,有限稀释法克隆细胞。ELISA及IF证明抗体特异性。克隆筛选出4株细胞,并初步建立了检测B19－VP2抗原的双抗体夹心酶联免疫吸附试验,为双抗体夹心法检测B19抗原为临床相关疾病诊断提供了检测手段。     

Passage of hybridomas in male BALB/c mice

For cultivating hybridomas in the ascitic form there are usually used female mice BALB/c and not male ones. Efficiency of production of monoclonal antibodies with cultivation of the hybridomas in male and female mice BALB/c was studied comparatively. The animals were stimulated to form ascite by administration of the incomplete Freund's adjuvant or 3 per cent peptone with petrolatum oil. Some parameters of the ascite formation were studied: viability of the hybridoma cells, ascitic fluid formation period and volume, hybridoma cell concentration and titers of monoclonal antibodies in the ascitic fluid. In regard to all the parameters studied the male animals were not inferior to the female ones and in case of one of the hybridomas even surpassed them twofold by the volume of the ascitic fluid formed. This is evident of possible using male mice for mass cultivation of hybridoma cells with a purpose of obtaining preparative amounts of monoclonal antibodies in production of immunodiagnostic agents on their basis.     

Monoclonal antibodies to hemagglutinin-neuraminidase and fusion glycoproteins of Newcastle disease virus: relationship between glycosylation and reactivity.

Eighteen hybridoma lines obtained by immunization of mice with Newcastle disease virus (NDV) lentogenic strain La Sota or velogenic strain Italien produced hemagglutinating monoclonal antibodies. The 18 monoclones were divided into four groups according to their reactivity toward native hemagglutinin neuraminidase protein (HN), nonglycosylated HN precursor, and heat-denatured HN blotted on nitrocellulose membranes. Only group II reagents were reactive toward their targets in all conditions tested. They were considered sequence-specific antibodies. Group I antibodies did not require glycosylation but lacked reactivity towards the denatured glycosylated antigen. Monoclonal antibodies from group III recognized only the native HN. Group IV was made up of a single monoclone that lacked reactivity with NDV Italien but recognized the La Sota strain in hemagglutination inhibition and enzyme-linked immunosorbent assays. Five hybridoma lines produced monoclonal antibodies which neutralized viral infectivity but failed to inhibit hemagglutination. One monoclonal antibody obtained after immunization of mice with NDV La Sota showed a low neutralization index versus NDV Italien. Four monoclonal antibodies derived from mice immunized with NDV Italien showed higher neutralization indices towards this strain. Neither the denatured F protein nor its nonglycosylated precursor was reacted against by the five monoclonal antibodies.     

抗重金属汞离子抗体的制备及鉴定

汞、镉、铅等重金属引起的环境污染已在世界范围内造成危害。快速、廉价地监测生境中重金属是减小其对人类及动物危害的先决条件。传统检测方法无法满足高通量的现场检测,建立更快速、更经济的免疫分析法检测汞离子是生产及经济发展的需要。本研究中,报道了汞特异性单克隆抗体的制备与筛选方法和结果。因Hg2+太小以至于不能引起免疫反应,所以用螯合剂(二乙烯三胺五乙酸,DTPA)将金属离子与载体蛋白(匙孔血蓝蛋白,KLH)连接起来。成功合成、鉴定汞复合物抗原后,免疫BALB/c小鼠,通过细胞融合获得了稳定分泌抗体的杂交瘤细胞。用极限稀释法亚克隆,通过ELISA筛选,获得了2株稳定分泌抗汞离子抗体的细胞株(H2H5,H1H8)。小鼠腹腔注射1×107H2H5、H1H8细胞株制备腹水,腹水抗体效价都在1∶51200以上。经鉴定两株杂交瘤均为IgG1亚类,轻链为kappa型且分泌抗体稳定性较好。实验结果为汞离子残留免疫学检测方法的建立提供了技术基础,对提高风险评估工作的效率和质量,保障食品安全有重要现实意义。     

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     

抗脂多糖单克隆抗体特性及纯化的研究

用Ｅ．ｃｏｌｉ０１１１：Ｂ４死菌体及其脂多糖（ＬＰＳ）免疫ＢＡＬＢ／Ｃ小鼠,取其脾细胞与ＳＰ２／０细胞融合获得６株稳定分泌抗ＬＰＳ特异性单克隆抗体细胞株,其中一株为ＩｇＧ２ａ类,５株为ＩｇＭ类,轻链均为Ｋ型;染色体数目为９０－９８条;５株ＩｇＭ类单克隆抗体识别５种不同的抗原表位;相对亲和力在１０~８～１０~（１０）之间;１Ｂ１２单抗经ＳｅｐｈａｄｅｘＧ－１５０纯化后,经还原性ＳＤＳ－ＰＡＧＥ显示只有７０ＫＤ的重键和２５ＫＤ的轻链。     

Isolation of monoclonal antibodies reactive with Marek's disease tumor-associated surface antigen (MATSA)

Two hybridoma clones producing monoclonal antibodies were obtained from mice immunized with the Marek's disease (MD)-lymphoblastoid cell line MSB1. These monoclonal antibodies reacted with the surface of MD-lymphoblastoid cell lines at higher titers than with avian lymphoid leukosis cell lines or with normal chicken thymus, bursa or peripheral blood lymphocytes. The serological specificity of these monoclonal antibodies seemed to correspond with that of rabbit antiserum reactive with MD tumor-associated surface antigen (MATSA).     

抗HIV-p24单克隆抗体细胞株的建立及初步应用

拟建立抗HIV-P24蛋白的单克隆抗体细胞株及双抗体夹心法,用于检测艾滋病人血清中的P24抗原。用纯化的基因工程表达的HIV-P24蛋白免疫BALB/c小鼠。取免疫小鼠的脾细胞和小鼠骨髓瘤Sp2/0的细胞融合,有限稀释法克隆细胞,ELISA筛选特异性抗体。结果克隆筛选出12株细胞,初步建立了检测HIV-P24抗原的双抗体夹心酶联免疫吸附试验。本方法为监控艾滋病病毒感染的窗口期和艾滋病病人临床治疗效果提供了检测手段。     

抗心型脂肪酸结合蛋白单克隆抗体制备、鉴定和在侧向免疫层析方法中的应用

目的:制备抗心型脂肪酸结合蛋白(H-FABP)单克隆抗体(mAb),并建立侧向免疫层析方法检测血浆中H-FABP。方法:用H-FABP蛋白免疫纯系Balb/c小鼠,采用杂交瘤技术建立能稳定分泌抗人H-FABP的单克隆杂交瘤细胞株。常规制备腹水,纯化后得到特异性抗H-FABP单克隆抗体,进行效价、特异性、亲和力的鉴定分析,并在ELISA平台进行抗体配对,用所筛选到的抗体对初步建立了检测H-FABP的侧向免疫层析方法。结果:成功获得12株稳定分泌抗体的阳性细胞株,并筛选出能相互配对,并应用于侧向免疫层析平台的抗体3D1和5F4,检测临床样品与对照试剂比较总符合率为100%。结论:筛选能稳定分泌抗体的细胞株,配对抗体应用于侧向免疫层析检测方法中,能快速、特异、灵敏的检测出临床样品中H-FABP,为临床应用快速检测H-FABP指标提供了方法和关键材料。     

Effects of passage number on growth and productivity of hybridoma secreting MRSA anti-PBP2a monoclonal antibodies

Monoclonal antibodies (mAb) are high added value glycoproteins recommended for immunotherapy, diagnosis, and also for the treatment of bacterial infections resistant to multiple drugs such as Methicillin Resistant Staphylococcus aureus (MRSA). In addition to environmental conditions related to cell cultures, the intrinsic characteristics of hybridoma cells, like the secretion stability of monoclonal antibodies by the cells through successive subcultures, are relevant for the characterization of cell lines related to the productivity of mAb. The rate of mAb production differs significantly between different cell lines and different passage numbers, and it is an important variable in characterization of cell lines. In order to find a more robust, faster-growing, and higher-productivity cell line of hybridoma, cultivations in 24-well plates were performed in different subculture periods, or cell passages (P), of hybridoma cells producing MRSA anti-PBP2a monoclonal antibodies [MRSA-antiPBP2a (mAb)]. The objective of this study was to study the effects of cell growth and production of MRSA-antiPBP2a mAb secreted by murine hybridoma cells grown in different passages as well as determine the which passages the hybridomas can be cultivated without harming their growth and productivity. So, cell growth profiles of hybridomas secreting MRSA-antiPBP2a (mAb) and the production of MRSA-antiPBP2a mAb in different subculture periods or cell passages (P) were studied. Cell growth tests, monoclonal antibody productivity, and metabolite characteristics revealed substantial differences in those cells kept between P10 and P50. Similarities in the secretion of monoclonal antibody, growth, and metabolic profiles, were noted in the MRSA-antiPBP2a mAb producing hybridoma cells kept between P10 and P20. Also, glucose consumption (g/L) and lactate production (g/L) in the latter cell cultures were monitored daily through biochemical analyzer. As of P30, it was observed a 4.4 times reduction in productivity, a 13 % reduction in metabolic yield, and a significant change in cell growth. Secretion of MRSA-antiPBP2a mAb should be obtained through the culture of hybridomas up to P20 in order to keep its stability.     

群特异性蓝舌病病毒单克隆抗体的制备和鉴定

目的：制备群特异性抗蓝舌病病毒（BTV）单克隆抗体,并对其特性进行鉴定,为建立检测BTV抗原及抗体的ELISA方法奠定基础。方法：用纯化的BTV颗粒为免疫抗原免疫BALB/c鼠,以大肠杆菌表达的VP7蛋白作为筛选抗原,用间接ELISA法筛选杂交瘤细胞株;选取抗体效价最高的一株制备BTV单克隆抗体,以该抗体为捕获抗体与8种不同血清型BTV进行ELISA反应,结果与细胞病变反应进行比对;以该抗体为竞争抗体,与12种不同血清型绵羊BTV抗血清进行竞争ELISA反应,并将结果与参比c-ELISA试剂盒结果进行比对。结果：筛选出5株稳定分泌BTV单克隆抗体的杂交瘤细胞株,并选其中一株（3E2）制备了高纯度的单克隆抗体;该单抗用于检测不同血清型BTV,与细胞病变反应结果完全相符;用于检测不同血清型绵羊BTV抗血清,其结果与参比c-ELISA试剂盒符合率为100%,与鹿流行性出血热病毒抗原和抗体均无交叉反应。结论：制备的BTV单克隆抗体具有良好的群特异性,可用于检测不同血清型BTV抗原及BTV抗体。     

Engineering Chinese hamster ovary (CHO) cells to achieve an inverse growth – associated production of a foreign protein, β-galactosidase

Protein synthesis in mammalian cells can be observed in two strikingly different patterns: 1) production of monoclonal antibodies in hybridoma cultures is typically inverse growth associated and 2) production of most therapeutic glycoproteins in recombinant mammalian cell cultures is found to be growth associated. Production of monoclonal antibodies has been easily maximized by culturing hybridoma cells at very low growth rates in high cell density fed- batch or perfusion bioreactors. Applying the same bioreactor techniques to recombinant mammalian cell cultures results in drastically reduced production rates due to their growth associated production kinetics. Optimization of such growth associated production requires high cell growth conditions, such as in repeated batch cultures or chemostat cultures with attendant excess biomass synthesis. Our recent research has demonstrated that this growth associated production in recombinant Chinese hamster ovary (CHO) cells is related to the S (DNA synthesis)-phase specific production due to the SV40 early promoter commonly used for driving the foreign gene expression. Using the stably transfected CHO cell lines synthesizing an intracellular reporter protein under the control of SV40 early promoter, we have recently demonstrated in batch and continuous cultures that the product synthesis is growth associated. We have now replaced this S-phase specific promoter in new expression vectors with the adenovirus major late promoter which was found to be active primarily in the G1-phase and is expected to yield the desirable inverse growth associated production behavior. Our results in repeated batch cultures show that the protein synthesis kinetics in this resulting CHO cell line is indeed inverse growth associated. Results from continuous and high cell density perfusion culture experiments also indicate a strong inverse growth associated protein synthesis. The bioreactor optimization with this desirable inverse growth associated production behavior would be much simpler than bioreactor operation for cells with growth associated production. This revised version was published online in August 2006 with corrections to the Cover Date.     

Serum-free hybridoma culture: ethical, scientific and safety considerations

Despite considerable progress in the development of cell culture techniques, including the development of the serum- and protein-free media that now routinely support hybridoma and mammalian cell growth, fetal bovine serum (FBS) supplemented media are still commonly used: a practice that raises ethical, scientific and safety concerns. The use of FBS in hybridoma culture media is examined here, with regards to the development and production of monoclonal antibodies (mAbs), and it is our recommendation that researchers adopt serum-free cell culture methods to reduce animal use in this area.