细胞培养中支原体污染的检测和去除

细胞培养中支原体污染是一个长期困扰实验室工作人员的难题。近年来,检测方法不断完善,核酸杂交,多聚酶链反应等新的方法已建立起来,对于支原体污染的去除主要是应用抗生素,可选用一些新的更为有效的药物。     

细胞培养中支原体污染的检测和去除

细胞培养过程中的支原体污染相当普遍。如何快速,简便地检测支原体,并且采取有效措施去除支原体一直是细胞工作者们亟待解决的难题。支原体检测方法有培养法,ＤＮＡ荧光染色法,单克隆抗体免疫荧光法。生化法,ＤＮＡ探针杂交法,ＰＣＲ法,支原体去除方法有药物法。免疫法,稀释法,加热法。本文就近年来有关支原体的检测及去除作一综述。     

细胞培养过程中支原体污染的检测和去除研究

细胞培养过程中的支原体污染相当普遍。如何快速、简便地检测支原体,并且采取有效措施去除支原体一直是细胞培养中急待解决的难题。本文就近年来有关支原体检测及去除方面的工作加以综述。     

细胞培养的支原体污染

<正>运用细胞培养进行病毒繁殖时,支原体污染是经常遇到的而且是非常严重的问题之一。这些污染对培养细胞产生各种各样的恶果:改变各种代谢活动致使不能进行培养细胞的正常生化研究;细胞生长速度减缓,迫使二倍体细胞系过早衰老,染色体发生畸变,并引起细胞形态的永久改变。事实表明:支原体污染虽会降低细胞培养中病毒的合成,但有时也能促进病毒的繁殖,这可能是支原体对干扰素产生的抑制。     

细胞培养中支原体污染的PCR检测

根据支原体16s rDNA序列,选择RemyTeyssou设计的三条寡核苷酸链,组成两套引物:P_(1-2a)能检测出细胞培养中常见的各种支原体,P_(1-2b)能检出无胆甾原体。反应可检出体系中10CFV的菌体。此法先用于对实验室人为污染支原体Vero细胞的检测,后与DNA 染色法和培养法比较,检测了49份生物样品,其中24份传代细胞,PCR检测的阳性率为58％,DNA染色法为42％,培养法为33％;三者的灵敏性比较,PCR可检出10~(-3)稀释度的阳性样品,高于其他两种方法。此PCR方法快速、灵敏、特异,适用于细胞培养中支原体污染的检测。     

用PCR检测细胞培养中支原体污染

细胞培养中支原体污染已经成为严重的问题.为了扩增6种支原体(精氨酸支原体,口腔支原体,人型支原体,猪鼻支原体,发酵支原体及莱氏支原体)核糖体RNA操纵子的16s和23s DNA间区,设计了三个通用PCR引物(F1,F2及R1).当以6种支原体DNA为模板时,引物F1和R1产生340到468bp的片段,引物F2和R1产生145到211bp的片段,当用Hela细胞或E.coli DNA作为模板,用引物F1和R1时,在电泳中未观察到特定区带.此法最小能检出8.5fg精氨酸支原体DNA,相当于13个精氨酸支原体.这说明,当这些支原体污染细胞培养时,能用PCR法检测出来.     

从传代细胞株中去除支原体污染的研究

用抗菌药物从传代细胞株中去除支原体污染的试验结果表明,卡那霉素和庆大霉素对支原体均无明显的杀灭作用。用lOμg／ml的Tiamutin处理支原体的效果较好。采用单克隆细胞稀释、选择法与Tiamutin(10μg／ml)处理相结合,经电镜观察可去除细胞中支原体的污染。检查支原体的方法是否特异、敏感、快速是对试验结果正确判断的一个重要的关键。为了防止支原体的污染,除了加强对原材料(包括小牛血清、培养液等)的检查以及把住严格的无菌操作条件外,必要时可在培养基中加入10μg／ml的Tiamutin。     

细胞培养中支原体污染的检测

本文介绍以应用指示细胞培养物的DNA荧光染色为主,辅之以微生物培养(支原体营养肉汤和琼脂培养)的方法作为细胞培养中的支原体污染的检测系统。用该系统检测了45个细胞系,支原体等微生物污染达66.6％,其中确证支原体污染率为31％。     

用Ciprofloxacin去除传代细胞株中的支原体污染的研究

在应用细胞培养手段的生物学研究和生物工程产品中,支原体污染仍是一个非常棘手的问题。对Ｖｅｒｏ和ＳＰ２／０－Ａｇ１４等细胞,应用Ｃｉｐｒｏｆｌｏｘａｃｉｎ,１０μｇ／ｍｌ处理１４天,支原体检测全部转阴,经４个月的培养、传代、冻存、复苏,每次支原体检测均保持阴性。对去除了支原体的Ｖｅｒｏ和ＩＳＣ－１１６细胞株,测试了其生长特征和功能,均未见受影响。     

Comparison of a quadroma and its parent hybridomas in fed batch culture

A quadroma (#22 × 63), formed by the fusion of two hybridomas, and its parent hybridomas (#22 and FMC 63) were each grown in fed batch cultures in order to examine the change in antibody productivity over time of the quadroma compared to its parent hybridomas. The growth rate, glucose uptake rate and lactate production rate of the quadroma were found to be intermediate between those of its parent cells of origin. The specific antibody productivity and internal antibody content of the quadroma followed the same decreasing trends over time as those seen in both parent hybridomas. Losses in specific antibody production rate and antibody content, however, occurred at a faster rate for the quadroma than for either of its parent hybridomas. Although the growth of a non-producing subpopulation is presumed to account for the drop in antibody production, there was no direct correlation between the percentage of high antibody containing cells, as determined by flow cytometry, and the specific antibody production rate.     

抗猪鼻支原体单克隆抗体的研制及双抗体夹心ELISA检测法的建立

目的 制备多种抗猪鼻支原体的单克隆抗体,建立双抗体夹心ELISA方法用于该病原体的检测。方法用猪鼻支原体CVCC361免疫BALB／c小鼠,采用杂交瘤技术和酶联免疫吸附实验筛选出抗该病原体的单克隆抗体;运用免疫双向扩散试验、Western blotting确定I异G亚类及针对抗原的相对分子质量;筛选出配对抗体,建立双抗体夹心ELISA的检测方法,并评价其灵敏度和特异性。结果共筛选出17株单克隆抗体,抗体亚类分别为IgG1、IgG2a、IgG2b、IgG3,免疫印迹结果表明单抗ZB1、ZB2及ZB16与相对分子质量为35×103的抗原有特异性结合,而ZB3和ZBIO与相对分子质量为70×10^3的抗原有特异性结合。确定了2个配对抗体（ZB1-ZB1-HRP和ZB1-ZB2-HRP）,可检出最小抗原量为30ns／mL,检出猪鼻支原体活菌8．34×10^2CFU／mL,与人呼吸道常见的致病菌及支原体均无非特异性反应。结论筛选的单克隆抗体具有较高的特异性和敏感性,应用双抗体夹心ELISA方法可用于猪鼻支原体的检测。     

Fed-batch culture optimization of a growth-associated hybridoma cell line in chemically defined protein-free media

An investigation was made to study the processes of fed-batch cultures of a hybridoma cell line in chemically defined protein-free media. First of all, a strong growth-associated pattern was correlated between the production of MAb and growth of cells through the kinetic studies of batch cultures, suggesting the potential effectiveness of extending the duration of exponential growth in the improvement of MAb titers. Second, compositions of amino acids in the feeding solution were balanced stepwisely according to their stoichiometrical correlations with glucose uptake in batch and fed-batch cultures. Moreover, a limiting factor screening revealed the constitutive nature of Ca²⁺ and Mg²⁺ for cell growth, and the importance of their feeding in fed-batch cultures. Finally, a fed-batch process was executed with a glucose uptake coupled feeding of balanced amino acids together with groups of nutrients and a feeding of CaCl₂ and MgCl₂ concentrate. The duration of exponential cell growth was extended from 70 h in batch culture and 98 h in fed-batch culture without Ca²⁺/Mg²⁺ feeding to 117 h with Ca²⁺/Mg²⁺ feeding. As a result of the prolonged exponential cell growth, the viable and total cell densities reached 7.04 × 10⁶ and 9.12 × 10⁶ cells ml⁻¹, respectively. The maximal MAb concentration achieved was increased to approximately eight times of that in serum supplemented batch culture.     

筛选抗甲3型（H3N2）流感病毒单克隆抗体ELISA间接方法的建立

用血凝抑制实验方法,虽可直接筛选到抗甲_3型流感病毒血凝素(H)单克隆抗体,但检测出的杂交瘤培养物上清中有小牛血清,做血凝抑制时还需用受体破坏酶处理去除非特异性抑制物。为减少麻烦我们建立了便于大批检测和筛选抗甲_3型(H_3N_2)流感病毒单克隆抗体的ELISA间接方法。     

抗t-PA单克隆抗体的制备及初步应用

用猪心t-PA和人黑色素瘤细胞分泌的t-PA作抗原,经腹腔及脾内免疫Bal b/c小鼠。用细胞融合技术制备杂交瘤细胞,细胞融合串达85％,获得4株抗t-PA杂交瘤细胞株,鼠腹水抗体效价达1∶10~5;Western Blot结果表明该单抗所结合的抗原分子量与t-PA相符,证明所获得的单抗为特异的抗t-PA单抗;对t-PA的纤溶活性中和抑制试验结果表明,4株单抗中的1株能完全抑制st-PA的纤溶活性,另外3株表现出程度不等的抑制;其中1株亚类为IgG,另外3株为IgM。杂交瘤细胞株无支原体污染;染色体数目正常。对该抗体进行初步纯化后,将其应用于rt-PA的研究中。     

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。     

Use of Taguchi's methods as a basis to optimize hybridoma cell line growth and antibody production in a spinner flask

Taguchi’s methods were used for the design of an experimental strategy aimed at optimizing cell density and monoclonal antibody (mAb) production from a spinner flask hybridoma culture. 23G11 is an antibody to the human leukocyte adhesion molecule, CR3 or β 2 integrin (CD11b/CD18). It recognizes specifically the A-domain of the α subunit CD11b. Anti β 2 integrin monoclonal antibodies hold a great potential for preventing inflammation mediated tissue injuries. An L8 orthogonal experimental design was used to investigate four different culture components: stirring speed, nature of serum, concentration of serum and nature of media (RPMI 1640 or RPMI 1640 supplemented with glucose and glutamine). The experiments were conducted using two levels for each factor studied and a direct ELISA test was used to estimate the level of antibody production. Statistical analysis of the collected data pointed to the stirring speed and serum concentration, and the interaction between these parameters, as the components that affected cell growth. Antibody production was affected by these factors and by the nature of medium but also by the following two interactions: stirring speed/nature of serum and stirring speed/concentration of serum. This study emphasizes the value of using Taguchi’s methods as a basis for optimization of mAb production from a hybridoma culture, in cost effective and significantly less labor intensive ways. This revised version was published online in August 2006 with corrections to the Cover Date.     

乙型肝炎病毒表面抗原a、d、r亚型单克隆抗体的制备与应用

本文成功地建立了分泌抗乙型肝炎病毒表面抗原(抗-HBsAg)a,d、r3种亚型决定簇抗体的4株杂交瘤细胞。经一系列生化、免疫学鉴定,证明4株细胞所分泌的单克隆抗体(McAb)均具有各自的亚型特异性。反复克隆培养16周,并液氮冻存8个月后复苏,抗体的效价仍稳定不变。用纯化的McAb制备RPHA诊断试剂,检测了80例有乙型肝炎自觉症     

抗汉坦病毒等三种单克隆抗体细胞株的建立及分析应用

以纯化的病毒抗原加完全福氏佐剂,免疫BALB/c小鼠,再利用杂交瘤技术建立针对汉坦病毒、狂犬病毒及乙型脑炎病毒的单克隆抗体(McAb)细胞株,制备并提纯标记McAb,应用于各种实验和检测工作。结果获得了6株分泌抗汉坦病毒McAb杂交瘤细胞株、6株分泌抗狂犬病毒McAb杂交瘤细胞株、2株分泌抗乙型脑炎病毒McAb杂交瘤细胞株,共14株,并对它们的特性进行了分析。各McAb效价不尽相同,有的高达10-7,有的则不足10-3。各McAb亚型以IgG型为主,少数为IgM型;轻链以κ型为主,个别为λ型或阴性。McAb与纯化的病毒抗原有明显的特异性吸附(P<0.01)。有的McAb有相同的作用位点,有的McAb则没有,但与其它McAb有交叉反应。通过对McAb进行提纯和标记,建立了双抗体夹心ELISA法,用于病毒抗原的检测。实验表明获得的McAb有较好的生物学特性,可与相应的病毒抗原特异性结合,用于免疫学检测及其它多种用途。     

抗人Leptin单克隆抗体的制备、鉴定及初步应用

本研究用本室制备的重组人Leptin为抗原,以鼠伤寒沙门氏裸菌为佐剂,通过脾内、腹腔、静脉三种途径相结合免疫BALB/c鼠,以PEG为促融剂,将免疫小鼠的脾细胞和SP2/0细胞进行融合,HAT、HT选择性培养基、间接ELISA筛选阳性克隆,有限稀释法进行4次克隆化,获得三株能稳定分泌抗人Leptin单抗的杂交瘤细胞株。对所获得的细胞株及其分泌的单抗特性进行较系统的鉴定显示,获得的单抗特异性高,亲和力强,免疫球蛋白亚类均为IgG3。初步应用的研究显示,获得的单抗不仅可用于体外Leptin的免疫印迹检测,而且可通过免疫组化、免疫荧光等技术用于脂肪组织中Leptin的检测,为Leptin的基础和临床研究奠定了基础。