杂交瘤细胞体外大规模培养研究进展

单克隆抗体在生物学和医学研究领域中显示了极大的应用价值,是免疫检验中的新型试剂,是生物治疗的导向武器。作为医学检验试剂,单克隆抗体可以充分发挥其优势,如特异性好,灵敏度高,更便于质量控制,利于标准化和规范化。传统的方法是利用小鼠腹水制备单克隆抗体,但是近几十年杂交瘤细胞体外大规模培养制备单克隆抗体技术也在不断发展。特别是单克隆抗体在疾病诊断和治疗方面的需求,更进一步促进了杂交瘤细胞体外培养生产技术的发展,体外培养杂交瘤细胞生产的单克隆抗体已应用到许多方面。由于杂交瘤细胞的半贴壁性质,无论是悬浮培养还是贴壁培养,均可进行杂交瘤细胞的体外大规模培养。针对应用于体外诊断试剂的杂交瘤细胞体外培养制备单克隆抗体进行综述,主要包括中空纤维细胞培养和生物反应器细胞培养方法,以及不同培养方法优化的进展。     

单克隆抗体及其抗感染作用的研究进展

骨髓瘤细胞和单个B细胞可融合形成杂交瘤细胞,这种细胞分离并克隆后可产生针对单一表位,且结构和功能相同的抗体,即单克隆抗体(monoclonal antibody, mAb)。单克隆抗体发展历程经历了四个阶段。其制备技术也在不断革新与发展。目前单克隆抗体技术发展日益成熟,在疾病治疗与诊断中发挥着关键的作用。单克隆抗体与天然抗体不同,具有效价高、特异性强、交叉反应少、可大量制备,靶向性高等特点。mAb可用于诊断及治疗感染性疾病、自身免疫病以及癌症等。对mAb的发展历程及mAb在抗感染性疾病中的应用进行简要阐述。     

小鼠杂交瘤单克隆抗体快速制备技术研究进展

小鼠杂交瘤单克隆抗体来源稳定、后期易制备、产量高,是免疫学中使用最为普遍的抗体.传统的耗时费力的杂交瘤制备技术无法满足日益增长的市场需求.文中从抗原设计筛选、B细胞富集与筛选、骨髓瘤细胞的改造、融合技术的改进、阳性杂交瘤细胞筛选及单克隆抗体性能快速测定中所涉及的快速制备技术方面进行阐述,以期为系统化的小鼠杂交瘤单克隆抗...     

人B细胞永生化研究进展

人源单克隆抗体具有免疫原性低、半衰期长等优势,成为了体内应用中不可或缺的生物制剂.人类抗体库为人源单克隆抗体的制备提供了丰富的来源,人B细胞永生化是获得人类抗体库的潜在有效方法,可应用于人源单克隆抗体的制备.由于各平台均有亟待解决的问题,基于人B细胞永生化的抗体制备尚局限在实验室研究阶段,且目前尚缺乏一篇系统综述以明确...     

单个B细胞抗体制备技术及应用

单克隆抗体是现代生命科学研究的重要工具,为许多领域的发展作出了不可估量的贡献。随着PCR技术和单克隆抗体技术的发展和成熟,单个B细胞抗体制备技术迅速兴起。该技术能够对单个的抗原特异性B细胞进行抗体基因的体外克隆和表达,保证了轻重链可变区的天然配对,相较于传统的抗体制备技术具有效率高、全人源、基因多样性更丰富等优势。单个B细胞抗体制备技术已成为制备全人抗体的热门方法,同时也促进了包括抗体发生成熟、疫苗保护机制、疫苗开发、肿瘤及自身免疫疾病等免疫学相关研究。文中就单个B细胞抗体制备技术的过程及应用作简要综述。     

简讯

上海细胞生物学学会于1986年4月21日在上海医科大学放射生物研究所开展上海细胞生物学学会季度学术活动,会上邀请上海医科大学病理生理学教研室林云璐教授作关于细胞培养与单克隆抗体技术与进展的报告,内容有一、单克隆抗体技术研究简史二、单克隆抗体的制备三、单克隆抗体在医学上的应用。参加人员有本市细胞生物学研究人员、各大专院校的教师与研究生共100余人,报告尚有书面材料,与会者一致认为报告非常精彩、内容丰富,既有理论又有宝贵的     

抗重组人表皮生长因子单克隆抗体的制备及生物学特性鉴定

建立能稳定分泌特异性抗重组人表皮生长因子(rhEGF)单克隆抗体的杂交瘤细胞株 ,制备出高效价的 ,具有生物学活性的抗重组人表皮生长因子单克隆抗体 ,为EGF及其单克隆抗体在肿瘤生长调节中的作用研究 ,为肿瘤的诊断与治疗提供具有实用价值的研究工具。此外 ,为EGF的亲和层析纯化提供材料。以BALB/c小鼠脾细胞为饲养细胞 ,运用细胞杂交瘤技术制备 ,间接ELISA法筛选出能稳定分泌针对人表皮生长因子的单克隆抗体细胞株 ;对杂交瘤细胞进行染色体核型分析并以体内诱生法产生腹水以获得大量单克隆抗体 ,并采用HiTrapProteinAHP柱对其纯化…     

抗果蝇MRJ蛋白单克隆抗体的制备和鉴定

制备抗果蝇MRJ蛋白单克隆抗体可用于研究果蝇mrj的生物学功能,使用IPTG诱导重组质粒pET28a-mrj在大肠杆菌Rosetta中表达,重组蛋白经过Ni-IDA凝胶柱亲和纯化后免疫BALB/c小鼠。然后取免疫好的小鼠的脾脏细胞与小鼠骨髓瘤细胞SP2/0融合,经克隆和筛选获得了能分泌抗果蝇MRJ蛋白单克隆抗体的杂交瘤细胞株。腹水制备后获得单克隆抗体,通过ELISA和Western Blot对所获得的抗体进行鉴定,结果表明所制备单克隆抗体能够特异性结合于原核及真核细胞表达的MRJ蛋白,可用于研究mrj基因的生物学功能。     

单克隆抗体的研究进展

单克隆抗体是一种由骨髓瘤细胞和带有抗体的B淋巴细胞结合形成的杂交瘤细胞,简称单抗。首先,本文对单克隆抗体的研究发展历程进行了分析和探讨,指出单克隆抗体的发展历程包括鼠源性单抗、嵌合抗体、人源化抗体以及人源性抗体这四大阶段,分别对其优缺点进行了说明;接下来,又对单克隆抗体在临床上的应用进行了说明,从疾病诊断方面及疾病的治疗两方面进行探讨。     

抗传染性犬肝炎病毒单克隆抗体的制备及鉴定

目的制备传染性犬肝炎病毒单克隆抗体。方法将用纯化的犬腺病毒1型（CAV-1）免疫的BALB／c小鼠脾细胞与SP2／0细胞在聚乙二醇作用下融合,通过酶联免疫吸附试验（ELISA）和免疫酶试验（1EA）筛选,以有限稀释法克隆3次,制备单克隆抗体,并对制备完成的单克隆抗体进行生物学鉴定。结果成功得到2株能稳定分泌抗CAV-1的单克隆抗体杂交瘤细胞,命名为1B、2H3,经鉴定其亚型分别为IgG2a和IgG2a,2株均为kappa链。腹水的ELISA效价可达10^7-10^8,IEA效价可达1：2560—1：5120。该单克隆抗体与CPV、CDV、FPV、CCV病毒无交叉反应。结论成功制备了抗CAV-1单克隆抗体,为进一步建立相关诊断方法奠定了基础。     

IgG production in hybridoma batch culture: kinetics of IgG mRNA, cytoplasmic-, secreted- and membrane-bound antibody levels

During batch cultivation of the I.13.17. hybridoma cell line, there is a 15 to 20-fold decrease in the levels of cytoplasmic and membrane-bound mAb, and a 7 to 10-fold decrease in the cellular levels of kappa and gamma chain mRNAs, as the cells pass from the exponential into the decline phase of growth. The profile of the specific mAb production rate does not correlate with the kinetics of either the cytoplasmic mAb or the specific mRNAs throughout the culture. Flow cytometry analyses have revealed that dead cells, which account for 40 to 70% of total cells during the decline phase, might significantly interfere with the determination of cytoplasmic mAb levels of cell-lysates ELISA and with the calculation of the specific mAb production rate. Possible influences of these parameters on mAb synthesis and secretion during hybridoma batch culture are discussed.     

Interleukin 2 up-regulates its own production

It has been previously reported that a combination pair of anti-CD2 monoclonal antibodies (mAb) T11(2)+T11(3) induces a strong proliferation of T cells, which does not require the involvement of accessory cells and exogenous interleukin 2 (IL-2). More recently, we have shown that the requirement for optimal T cell proliferation depends on the combination pairs of anti-CD2 mAb used. Among them, anti-GT2+T11(1) mAb do not allow optimal proliferation of TA4 helper cloned T cells due, at least in part, to a low level of IL-2 production. This observation offered us the opportunity to study the effect of IL-2 on its own production. We show here that stimulation of cloned TA4 cells with anti-GT2+T11(1) mAb induces only a marginal level of IL-2 production. By contrast, significantly higher levels of IL-2 activity are detected in the culture supernatant of TA4 cells preincubated with recombinant IL-2 (rIL-2) before stimulation with anti-GT2+T11(1) mAb. This effect is dose-dependent over a wide range (5 to 50 IU/ml) of rIL-2 concentrations added during preincubation time. In addition, it is not due to carryover of rIL-2 bound during the preincubation time, or to lesser IL-2 consumption by these cells, or to increasing numbers of IL-2-producing cells induced by exogenous IL-2. Moreover, the observation was confirmed with IL-2 mRNA. Although neither rIL-2 nor anti-GT2+T11(1) mAb alone could induce a significant production of IL-2, rIL-2 appears to up-regulate its own production when the TA4 cells are activated by the anti-CD2 mAb-mediated second signal.     

Characterization of antibody variants during process development: The tale of incomplete processing of N-terminal secretion peptide

Monoclonal antibodies (mAbs) have emerged as one of the most important classes of biotherapeutics, although development of these molecules is long and arduous. A production cell line must be established, and growth conditions for the cells and purification processes for the product must be optimized. Integration of the appropriate analytical strategies in these activities is the cornerstone of Quality by Design and in-process control approaches are encouraged by the Food and Drug Administration. We report here the development of a reversed phase-high performance liquid chromatography (RP-HPLC) method to follow the presence of a mAb product-related variant observed during the purification process development. The variant eluted as a later peak on RP-HPLC, compared with the mAb control (3.25 min and 2.85 min, respectively). We isolated this hydrophobic variant and further analyzed it by mass spectrometry. We identified the variant as a mAb with an incompletely processed leader sequence attached to the N-terminus of one of the two heavy chains.     

Violacein improves recombinant IgG production by controlling the cell cycle of Chinese hamster ovary cells

Cytotechnology - Chinese hamster ovary (CHO) cells are used as host cells for industrial monoclonal antibody (mAb) production. Cell cycle control is an effective approach to increase mAb production...     

Characterization of antibody variants during process development: The tale of incomplete processing of N-terminal secretion peptide

Monoclonal antibodies (mAbs) have emerged as one of the most important classes of biotherapeutics, although development of these molecules is long and arduous. A production cell line must be established, and growth conditions for the cells and purification processes for the product must be optimized. Integration of the appropriate analytical strategies in these activities is the cornerstone of Quality by Design and in-process control approaches are encouraged by the Food and Drug Administration. We report here the development of a reversed phase-high performance liquid chromatography (RP-HPLC) method to follow the presence of a mAb product-related variant observed during the purification process development. The variant eluted as a later peak on RP-HPLC, compared with the mAb control (3.25 min and 2.85 min, respectively). We isolated this hydrophobic variant and further analyzed it by mass spectrometry. We identified the variant as a mAb with an incompletely processed leader sequence attached to the N-terminus of one of the two heavy chains.     

Differential CD3/T cell antigen receptor-mediated IL-2 production in jurkat T cells. Dissociation of IL-2 response from total inositol phosphate and calcium responses

We used three anti-human anti-CD3 mAb each recognizing different surface CD3 epitopes to differentially perturb the CD3/TCR complex on the surface of Jurkat T cells. In the presence of phorbol ester, these anti-CD3 mAb triggered differential IL-2 production in Jurkat T cells, which could not be explained by differences in kinetics of IL-2 production, by differences in IL-2 adsorption caused by differential surface expression of p55 or p75 IL-2R, by effects on IL-2 secretion rather than actual synthesis, or by differential toxicities of the anti-CD3 mAb to Jurkat cells. In addition, this differential anti-CD3-induced IL-2 production could not be explained by differences in mAb isotype or in avidities of the anti-CD3 mAb for the Jurkat cells. Moreover, anti-CD3 mAb covalently immobilized onto beads also differentially induced IL-2 production in Jurkat cells, suggesting that the differential IL-2 response is not based on differential rates of anti-CD3-induced modulation of Jurkat cell surface CD3. Although differences among the anti-CD3 mAb in the initial rates of binding to Jurkat cell were observed, this was also believed unlikely to explain the differential IL-2 response. Regardless of the anti-CD3 mAb used, anti-CD3-induced total inositol phosphate (IP) production did not necessarily correlate with anti-CD3-induced IL-2 production. Nevertheless, despite the differences among the anti-CD3 mAb in inducing IL-2 production, the calcium responses were grossly similar. Taken together, these observations indicate that CD3/TCR-mediated IL-2 production in Jurkat cells can be dissociated from total IP generation, and the basis of differential CD3/TCR-mediated IL-2 production in these cells does not appear to be at the level of the initial activation-induced calcium response. These studies suggest that the nature of the CD3/TCR ligand (its physical form and/or the specific epitope it perturbs) can either directly influence intracellular events distal to the generation of IP and increase in intracellular free calcium leading to differential IL-2 production or can trigger IP-independent pathways that affect IL-2 production.     

Dichotomous effect of monocyte Fc receptor interaction on anti-CD3-induced immunoglobulin synthesis

Monoclonal antibodies against the TCR/CD3 complex are capable of activating T cells which in turn may induce immunoglobulin synthesis in B cells under appropriate conditions. Here we present evidence that distinct immune responses, induced by four commonly used TCR/CD3 mAb (Leu4, OKT3, BMA030, BMA031) were related to the mAb interaction with monocyte Fc receptors for IgG. Depending on their isotype and on the technique by which they were crosslinked, TCR/CD3 mAb induced variable IgM and IgG synthesis in PBMC: If the mAb were crosslinked by monocyte IgG-Fc receptors they induced a high Ig production, while crosslinking the same mAb by plastic-bound goat anti-mouse antibodies (panning) failed to do so. Nevertheless, both crosslinking techniques triggered a strong proliferation and IL-2, IL-4, and IFN gamma lymphokine gene expression. The lack of Ig production under panning conditions was due to an additional IgG-Fc receptor interaction with monocytes: (a) If namely mAb F(ab')2 fragments, or mAb isotypes unable to bind to monocyte Fc receptors (IgG2b, IgG1 in nonresponders) were crosslinked by panning, both a good proliferation as well as Ig production ensued; (b) if TCR/CD3 mAb isotypes which could additionally bind to monocyte Fc receptor (IgG2a) were crosslinked, no Ig production occurred; (c) if mAb F(ab')2 fragments were crosslinked with a second anti-T cell antibody of IgG2a isotype, which could bind to monocyte Fc receptors, Ig synthesis was reduced. Interestingly enough, this diminishing effect, due to monocyte Fc receptor interaction, was only observed if CD4-positive cells were proliferating, but not if CD8-positive cells were activated.     

HUMAN B CELL DIFFERENTIATION: DEPENDENCE ON INTERACTIONS WITH MONOCYTES AND T LYMPHOCYTES VIA CD40, CD80 (B7.1), AND THE CD2-LIGANDS CD48 AND CD58 (LFA-3)

B cell differentiation depends on cellular interactions with T lymphocytes and monocytes via adhesion molecules (AM). In order to characterize AM which are required for B cell differentiation immunoglobulin production using unseparated peripheral blood mononuclear cells (PBMC) was studied. Unstimulated human PBMC were cultured for 9 days with mAb directed at CD2/CD48, /CD58, CD59, CD5/CD72, CD11a—CD18/CD54, CD28/CD80, CD86, CD40/CD40L, or rat CD2 (control). B cell differentiation was quantified measuring IgM and in some cases IgA, IgG, and IgE production. IgM levels were significantly reduced by mAb against CD40, CD48, CD58 and CD80. The reduction was not due to isotype switching to IgA, IgG or IgE. The role of CD40, CD48, CD58 and CD80 was further investigated after depletion of different cell types. Depletion of monocytes and NK cells resulted in no detectable IgM production irrespective of added mAbs. In contrast, IgM production was still present after depletion of T cells and NK cells. Only mAb against CD80 and CD48 significantly reduced IgM production, the reduction of IgM production by anti-CD40 mAb was less than in the presence of T cells. Importantly, anti-CD58 mAb had no effect on IgM production after T cell and NK cell depletion. Taken together, the AM CD40, CD48, CD58, and CD80 are involved in Ig production of unseparated PBMCs. In this model of B cell differentiation only the AM CD58 depend on the presence of T cells while CD48 and CD80 help was found to be T cell independent.     

The role of CD11a/CD18-CD54 interactions in human T cell-dependent B cell activation.

The role of leukocyte function-associated Ag-1 (LFA-1, CD11a/CD18) and intercellular adhesion molecule 1 (ICAM-1, CD54) interactions in human T cell and B cell collaboration was examined by studying the effect of mAb to these determinants on B cell proliferation and differentiation stimulated by culturing resting B cells with CD4+ T cells activated with immobilized mAb to the CD3 molecular complex. In this model system, mAb to either the alpha (CD11a) or beta (CD18) chain of LFA-1 or ICAM-1 (CD54) inhibited B cell responses significantly. The mAb did not directly inhibit B cell function, inasmuch as T cell-independent activation induced by formalinized Staphylococcus aureus and IL-2 was not suppressed. Moreover, DNA synthesis and IL-2 production by immobilized anti-CD3-stimulated CD4+ T cells were not suppressed by the mAb to LFA-1 or ICAM-1. Although the mAb to LFA-1 inhibited enhancement of IL-2 production by co-culture of immobilized anti-CD3-stimulated CD4+ T cells with B cells, addition of exogenous IL-2 or supernatants of mitogen-activated T cells could not abrogate the inhibitory effects of the mAb to LFA-1 or ICAM-1 on B cell responses. Inhibition was most marked when the mAb were present during the initial 24 h in culture. Immobilized anti-CD3-stimulated LFA-1-negative CD4+ T cell clones from a child with leukocyte adhesion deficiency could induce B cell responses, which were inhibited by mAb to LFA-1 or ICAM-1. These results indicate that the interactions between LFA-1 and ICAM-1 play an important role in mediating the collaboration between activated CD4+ T cells and B cells necessary for the induction of B cell proliferation and differentiation, and for enhancement of IL-2 production by CD4+ T cells. Moreover, the data are consistent with a model of T cell-B cell collaboration in which interactions between LFA-1 on resting B cells and ICAM-1 on activated CD4+ T cells play a critical role in initial T cell-dependent B cell activation.