SYNTHESIS OF INTERFERON-α_A MONOCLONAL ANTIBODY PACKING MATERIAL IN HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY AND PURIFICATION OF RECOMBINANT HUMAN INTERFERON-α_A

A new way for the synthesis of human interferon—α_A monoclonal antibody (IFN-α_A-McAb) bound to silica gel packing material in high-performance affinity chromatography (HPAFC) has been developed. The high coupling efficiency and specific activity of IFN—α_A-McAb can be obtained by activated diol-silica gel with activating agent. After purification using this packing material in HPAFC, the specific activity of recombinant human interferon-α_A (rIFN-α_A) rose up to 1.03×10~7IU/mg protein and the purification efficiency is appoximately 100 times.

Expression of Anti-CD4 Human/Murine Chimeric Antibody and Their Killer Tumor Activity

From the mouse hybridoma cell line secreting an anti-CD4 monoclonal antibody (McAb), total RNA was prepared. The VH and VL genes were amplified by RT-PCR with family specific primer pairs. The PCR products were cloned into pGEM-T vectors, then tranfected into JM109. The VH and VL genes were snalyzed by automatic DNA sequencer. According to Kabat classification, the VH and VL genes belong to the mouse ig heavy subgroup Ⅱ(A) and x chain subgroupⅢ, respectively. The VH and VL genes were subcloned into pr1-Expr and Pk Expr respectively, then transfected into XL2-Blue. The VH- Pr1 and VL- pk were trans feeted by electroporation into mouse myeloma cell X63Ag8. 653. The transfectoma cells were selected by G418 screening, and then supernatant of cultured transfectoma were analyzed by ELISA and immunofluorescence techniques.We have acquired transfectoma cells secreting anti-CD4 chimeric antibodies.These chimeric antibodies are able to kill tumor cells specifically in vitro.

Expression and purification of Ctomp2aa167-aa434 and preparation of its mAb

Chlamydia trachomatis outer membrane protein 2 （Ctomp2） is a major immunogen in chlamydial infections and a highly genus-conserved structural protein of all Chlamydia species. To purify the protein and to prepare monoclonal antibodies （mAbs） against it, the recombinant protein was induced by IPTG, which was confirmed by SDS-PAGE and purified by means of a Ni^2＋ -charged resin colunm. The denatured protein was refolded in the GSH-GSSH buffer gradually and identified by Westem blotting. Then the BALB/c mice were immunized with the recombinant protein to prepare the mAb against Ctomp2. The obtained mAbs were characterized. Genital specimens were tested with indirect ELISA mostly made of the mAb and cell culture in 84 patients with genital symptoms. The results showed that high-level expression of the recombinant protein was achieved, which existed as inclusion body and amounted to 38 % of total bacterium protein. A mAb against Ctomp2 was obtained. It belongs to IgG 2b. The titers were as high as 1：40 000. The Western blotting showed that the mAb only reacted with the recombinant protein. It had no crossing reactions against E. coli, N. gonorhoea, M. hominis, U. urealyticum and M. penetrans. It had high specifity. In comparison with gold standard test-ceil culture, the sensitivities, specificities, positive predictive values and negative predictive values of indirect ELISA were 95.24%, 100%, 100% and 98.44%, respectively. The above-mentioned research work contributed not only to the further study of the structure and function of this protein, but also to the establishment of the method for its clinical application, for it had not been reported before.

Studies on Purification of Methamidophos Monoclonal Antibodies and Comparative Immunoactivity of Purified Antibodies

To purify Methamidophos (Met) monoclonal antibodies with two methods and compare immune activity of purified antibodies. Method Caprylic acid ammonium sulphate precipition (CAASP) method and Sepharose protein-A (SPA) affinity chromatography method were used to purify Met monoclonal antibodies, UV spectrum scanning was used to determine protein content and recovery of purified antibodies, sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE) was used to analyze the purity of purified antibodies, and enzyme-linked immunosorbent assay (ELISA) was used to determine immune activity of purified antibodies. Results Antibody protein content and recovery rate with CAASP method were 7.62 mg/mL and 8.05% respectively, antibody protein content and recovery rate with SPA method were 6.45 mg/mL and 5.52% respectively. Purity of antibodies purified by SPA method was higher than that by CAASP method. The half-maximal inhibition concentration (IC50) of antibodies purified by SPA to Met was 181.26 靏/mL, and the linear working range and the limit of quantification (LOD) were 2.43-3896.01 靏/mL and 1.03 靏/mL, respectively. The IC50 of antibodies purified by CAASP to Met was 352.82 靏/mL, and the linear working range and LOD were 10.91-11412.29 靏/mL and 3.42 靏/mL, respectively. Conclusion Antibodies purified by SPA method are better than those by CAASP method, and Met monoclonal antibodies purified by SPA method can be used to prepare gold-labelled testing paper for analyzing Met residue in vegetable and drink water.

PURIFICATION OF MONOCLONAL ANTIBODY 3HII AGAINSTGASTRIC CANCER FOR IN VIVO USE

Monoclonal antibody (McAb) 3Hll against gastriccancer was grown in the mouse ascites system. Toacquire a clinical grade product for cancer radioimmuno-imaging was purified by two step highperformance liquid chromatography (HPLC) protocolusing protein A and high-performance hydroxylapatite(HPHT). An analysis of data reported shows the twostep HPLC method to be the best purificationprocedure. This protocol satisfies purity and immunoreactivity requirement, and provides an sample sterility,free-pyrogens, free-mycoplasma and non-specific IgGcontamination. This procedure described was capable ofgenerating large amounts of clinical grade monoclonalantibody.

Anti-Proliferative Effects Induced by Anti-CD4 Human/Murine Chimeric Antibody and Murine Anti-CD4 Monoclonal Antibody

Summary: The effects of chimeric anti CD4 human/murine chimeric antibody and murine anti CD4 monoclonal antibody (McAb) on the proliferation induced by anti CD3 McAb, phytohemagglutinin (PHA), IL 2, and allogeneic cells were studied. The results showed that chimeric anti CD4 antibody and murine anti CD4 McAb could inhibit the proliferation induced by the above inducers and the inhibitory effects were related to the dosage of the antibodies.

牛早幼粒细胞白血病蛋白的原核表达及单克隆抗体制备

【目的】牛早幼粒细胞白血病蛋白(promyelocytic leukemia protein,PML)是细胞核亚结构PML核体(nuclear bodies,NBs)的骨架蛋白,在抗病毒内源性免疫中发挥重要作用。本研究旨在制备牛PML单克隆抗体,为研究PML NBs结构和功能准备物质材料。【方法】构建表达bPML基因截短体的重组质粒pET-32a-bPML,将重组质粒转化大肠杆菌Transetta(DE3)感受态细胞,IPTG诱导表达,利用SDS-PAGE和Western blotting对表达产物进行分析。将经镍柱亲和层析纯化后的重组蛋白免疫小鼠,制备单克隆抗体,应用ELISA方法鉴定单克隆抗体类/亚类和型,进一步鉴定该单克隆抗体识别的抗原表位;通过检测不同种属来源的细胞检测单克隆抗体的特异性;利用该单克隆抗体对外源转染牛PML的细胞进行Western blotting和间接免疫荧光试验(IFA)检测;利用该单克隆抗体建立的IFA检测不同的牛源细胞内源PML定位情况。【结果】牛PML在大肠杆菌中可溶性表达,分子质量大小为50 ku;以此纯化蛋白为免疫原制备出1株抗牛PML单克隆抗体bPML-2G5,其为IgG1亚类,轻链为Kappa型,识别表位位于牛PML结构域78 EQPRPSTSRA 88;Western blotting和IFA分析结果显示,bPML-2G5不仅可特异性识别外源转染的牛PML,而且还能特异性识别牛肾细胞、牛鼻甲骨细胞、牛胚气管细胞的胞核内核体结构中的PML。【结论】本研究成功制备了1株分泌牛PML单克隆抗体的杂交瘤细胞株,其分泌的单克隆抗体可用于检测外源性及内源性表达的牛PML。

小鼠抗NLRP3单克隆抗体的制备及鉴定

目的 制备小鼠抗含pyrin结构域核苷酸结合寡聚结构域样受体家族蛋白3(NLRP3)的单克隆抗体(mAb)并检测其特异性。方法 将编码小鼠NLRP3基因外显子3(Ms-N3)的基因片段插入载体p36-G3-throhFc中构建重组质粒Ms-N3-throhFc,然后将该质粒转染到HEK293F细胞中,进行真核蛋白表达。进一步利用蛋白A亲和层析柱纯化得到Ms-N3蛋白并免疫NLRP3基因敲除(NLRP3^(-/-))小鼠,将免疫小鼠的脾细胞与SP2/0骨髓瘤细胞融合形成杂交瘤细胞。进而通过ELISA和免疫荧光方法筛选能够分泌特异性识别小鼠NLRP3的mAb的杂交瘤细胞。结果 成功构建Ms-N3-throhFc重组质粒并证明该质粒能在HEK293F细胞中稳定表达。ELISA初步筛选获得12株杂交瘤细胞,经过免疫荧光实验检测发现其中的9-B8-3-2-C5分泌的mAb能够特异性识别非变性的小鼠NLRP3蛋白,该mAb的重链亚型为IgM,轻链亚型为κ。结论 成功获得小鼠抗NLRP3 mAb。

Cloning of 3H11 mAb variable region gene and expression of 3H11 human-mouse chimeric light chain

IM To clone mouse antihuman gastric cancer mAb(3H11) variable genes and to construct 3H11 humanmouse chimeric antibody.METHODS The entire VH and VL genes of antigastric cancer mAb 3H11 were cloned by RTPCR method from 3H11 hybridoma cells, using 5′ primers for leader sequences. The 3H11 VL gene was then inserted into humanmouse chimeric light chain expression vector and transfected into murine Sp2/0 myeloma cells.RESULTS DNA sequence analysis indicated that the cloned genes included the whole leader sequences and the mature Ig variable region encoding sequences. After gene transfection, transient expression of chimeric light chain protein was detected.CONCLUSION DNA sequences and transient expression indicated that the cloned gene was functional. This work laid basis for constructing 3H11 humanmouse chimeric antibody in the future..

Prevention and management of hepatitis B virus reactivation in patients with hematological malignancies in the targeted therapy era

Hepatitis due to hepatitis B virus(HBV)reactivation can be serious and potentially fatal,but is preventable.HBV reactivation is most commonly reported in patients receiving chemotherapy,especially rituximab-containing therapy for hematological malignancies and those receiving stem cell transplantation.Patients with inactive and even resolved HBV infection still have persistence of HBV genomes in the liver.The expression of these silent genomes is controlled by the immune system.Suppression or ablation of immune cells,most importantly B cells,may lead to reactivation of seemingly resolved HBV infection.Thus,all patients with hematological malignancies receiving anticancer therapy should be screened for active or resolved HBV infection by blood tests for hepatitis B surface antigen(HBsAg)and antibody to hepatitis B core antigen.Patients found to be positive for HBsAg should be given prophylactic antiviral therapy.For patients with resolved HBV infection,there are two approaches.The first is pre-emptive therapy guided by serial HBV DNA monitoring,and treatment with antiviral therapy as soon as HBV DNA becomes detectable.The second approach is prophy-lactic antiviral therapy,particularly for patients receiving high-risk therapy,especially anti-CD20 monoclonal antibody or hematopoietic stem cell transplantation.Entecavir and tenofovir are the preferred antiviral choices.Many new effective therapies for hematological malignancies have been introduced in the past decade,for example,chimeric antigen receptor(CAR)-T cell therapy,novel monoclonal antibodies,bispecific antibody drug conjugates,and small molecule inhibitors,which may be associated with HBV reactivation.Although there is limited evidence to guide the optimal preventive measures,we recommend antivi-ral prophylaxis in HBsAg-positive patients receiving novel treatments,including Bruton’s tyrosine kinase inhibitors,B-cell lymphoma 2 inhibitors,and CAR-T cell therapy.Further studies are needed to determine the risk of HBV reactivation with these agents and the best prophylactic strategy.

识别α-synuclein N端结构域的单克隆抗体鉴定及免疫应用

目的分析5种识别α-突触核蛋白(α-synuclein,α-syn)N端结构域的单克隆抗体1C16、2B8、2P21、3O18和1J6的特异性,为帕金森病(Parkinson s disease,PD)的早期诊断和免疫治疗提供抗体支持。方法体外蛋白重组技术获得人源α-syn蛋白(human-α-syn,h-α-syn)、鼠源α-syn蛋白(mouse-α-syn,m-α-syn)、β-syn蛋白、N端人源α-syn蛋白(α-syn/N)和去N端人源α-syn蛋白(α-syn/ΔN)。斑点印迹法鉴定5种单克隆抗体的特异性识别结构域,使用蛋白质印迹技术检测其对变性后的纯蛋白和鼠脑组织的识别情况。结果抗体1C16可以识别非变性的h-α-syn纯蛋白和小鼠脑组织中的变性的h-α-syn蛋白,不识别m-α-syn和β-syn。抗体1J6仅识别非变性的h-α-syn及α-syn/N纯蛋白,不识别变性后的全长α-syn纯蛋白和小鼠脑组织中的变性h-α-syn蛋白。结论筛选出的2种单克隆抗体具有特异性,可为本实验下一步生物标志物的酶联免疫吸附法测定检测和针对α-syn的免疫治疗提供基础。

莱克多巴胺单克隆抗体非亲和层析法纯化研究

抗体纯化对免疫测定和生物偶联的灵敏度、重现性和稳定性具有重要影响。本文对硫酸铵沉淀法(Ammonium sulfate precipitation,AS)及AS分别与阴离子交换层析法(Anion exchange chromatography,AEC)、阳离子交换层析法(Cation exchange chromatography,CEC)、疏水作用层析法(Hydrophobic interaction chromatography,HIC)和陶瓷羟基磷灰石法(Ceramic hydroxyapatite,CHT)联合应用纯化腹水来源的莱克多巴胺单克隆抗体(Ractopamine monoclonal antibody,RAC-mAb)进行了研究。优化缓冲液pH、盐浓度及层析介质,分别采用Bradford法、十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(Sodium dodecyl-sulfate polyacrylamide gel electrophoresis,SDS-PAGE)、间接竞争酶联免疫吸附试验(Indirect competitive enzyme-linked immunosorbent assay,icELISA)和胶体金免疫层析技术(Colloidal gold immunochromatography,CGIC)对抗体纯化后回收率、纯度及生物学活性进行评估。结果显示,采用AS+AEC法纯化抗体回收率高、纯度和生物学活性好,抗体回收率为40.1%,纯度为75.1%,经icELISA平行测定3次所得灵敏度(IC_(50))最佳为1.73±0.22 ng/mL,CGIC测定其在PBS及猪尿样本添加cut-off值分别为5 ng/mL和60 ng/mL。本研究为单克隆抗体纯化提供了理论参考和必要的实验基础。

应用A蛋白亲和层析法纯化单克隆抗体

应用Protein A亲和层析法,从采集的小鼠腹水中纯化出了抗凝血因子Ⅶ单克隆抗体,用SDS-PAGE和ELISA法分别检测了纯化后单克隆抗体的纯度及效价,结果显示,电泳为两条带,分别为免疫球蛋白G(IgG)的重链和轻链,纯化后的单克隆抗体纯度达到电泳纯,应用间接ELISA法测定腹水效价为1×10-7左右,与未纯化前无差异。结果表明,应用A蛋白亲和层析法能够得到纯度较高的单克隆抗体,适用于高纯度单克隆抗体的制备。

抗人CD40人-鼠嵌合抗体的构建及其表达

目的:通过基因工程抗体改造技术构建并表达抗人CD40人-鼠嵌合抗体。方法:从分泌鼠抗人CD40单克隆抗体(mAb)的杂交瘤细胞株(5C11)中提取总RNA,用一对特异性引物通过RT-PCR扩增mAbVH和VL的DNA编码区基因。根据序列分析的结果,设计引物扩增VH和VL基因相应的信号肽序列。利用基因重组技术,将mAb5C11的VH、VL基因及其相应信号肽序列与人IgG1的CH基因、Cκ链基因进行拼接,构建人-鼠嵌合抗体基因的表达质粒pIRES/h5C11。用脂质体法将其导入293T细胞株中进行瞬时表达。利用流式细胞术对表达产物进行鉴定。结果:NCBI基因数据库Blast的结果显示,克隆的基因序列符合小鼠VH、VL基因及其信号肽序列的特征。表达质粒pIRES/h5C11的构建正确,并在293T细胞株中获得瞬时表达。表达的抗人CD40的人-鼠嵌合抗体和mAb5C11具有相同的抗原结合位点。结论:成功地克隆了鼠抗人CD40mAbV区编码基因,并实现了可溶性抗人CD40的人-鼠嵌合抗体在293T细胞中的瞬时表达。

抗人膀胱癌人-鼠嵌合抗体真核表达载体的构建和表达

目的 :构建嵌合型抗人膀胱癌抗体的真核表达载体 ,并实现其真核表达。方法 :从杂交瘤细胞中克隆得到鼠源单抗的可变区基因 ,插入嵌合抗体IgG1真核表达载体pDHL中 ,转染CHO细胞 ,实现其真核表达 ,并对抗人膀胱癌人 鼠嵌合抗体的功能进行初步鉴定。结果 :成功构建抗人膀胱癌人 鼠嵌合抗体真核表达载体 ,并实现其真核表达。初步的功能鉴定表明抗人膀胱癌人 鼠嵌合抗体具有较好的特异性和亲合力。结论 :构建的抗人膀胱癌人 鼠嵌合抗体真核表达载体在真核细胞内得到表达 ,且其功能较为理想。

抗CD20嵌合抗体的表达与活性检测

表达了基因重组抗CD20嵌合抗体并对其生物学活性进行了初步鉴定。设计合成轻、重链可变区序列;提取血液RNA,通过RT-PCR得到人κ、IgG1的轻、重链恒定区序列。运用重叠延伸PCR,连接可变区与恒定区,将轻、重链基因连接至pIRES双表达载体。将质粒以阳离子脂质体转染CHO细胞,ELISA挑选阳性克隆,共获得7株表达较高的克隆,表达量约为2mg/L。扩大培养阳性克隆anti-CD20-1B3,收获上清,以蛋白A进行亲和层析纯化表达蛋白。SDS-PAGE检测表明纯化纯度达到95%,蛋白相对分子量与理论值吻合。以CD20+细胞Raji、Daudi、Ramous检测,表明该抗体能与CD20抗原特异性结合,体外杀伤试验说明抗体能够杀伤CD20+淋巴瘤细胞。

人心肌肌钙蛋白T的纯化和单克隆抗体的制备

从人左室心肌中成功纯化心肌肌钙蛋白Ｔ（ｃＴｎＴ）．经匀浆，７０℃加热处理，咪唑盐酸透析，ＤＥＡＥ－纤维素层析，１００ｇ心肌获取ｃＴｎＴ５ｍｇ，纯度为９７．６％．同时采用脾内免疫法，免疫Ｂａｌｂ／Ｃ小鼠，经细胞融合，筛选，克隆化得５株稳定分泌抗人ｃＴｎＴ单克隆抗体（ＭｃＡｂ）的杂交瘤细胞（Ｇ３，Ｇ８，Ｇ１０，Ａ５，Ａ７），４株为ＩｇＭ，１株为ＩｇＧ，染色体数目９２～１１０条．腹水效价为３．２×１０－６～１．６×１０－７．

抗基因工程干扰素单克隆抗体的纯化

为获得纯化的单抗以制备高效的单抗亲和层析柱,采用盐析、DEAE-Sephacel离子交换层析和Sephacryl S-_(300)凝胶过滤层析方法,对IgG亚类不同的抗人α-1和α-2a型基因工程干扰素(rHu-IFN-α)单抗进行纯化。结果,11D_2(IgG_(20))的纯度为81.5％,活性回收率为58.3％;17D_9(IgG_1)的纯度为91.1％,活性回收率为73.1％;1A_5(IgG_1)的纯度为93.7％,活性回收率为96.0％;1B_5(IgG_1)的纯度为97.0％,活性回收率为73.7％;27A_7(IgG_(2a))的纯度为93.4％,活性回收率为79.0％。

单克隆抗体纯化的研究进展

单克隆抗体在现代生物检测领域和医疗领域起着越来越重要的作用。而不管是何种抗体,来源于哪种形式,在用于检测和治疗之前都需进行纯化,纯化的方法因抗体种类和用途不同而不同。大致可分为沉淀法和色谱法两大类,作者就各种不同方法的应用范围及纯化结果的纯度、活性回收率、纯化周期、每批可纯化样品量、纯化成本等方面进行了比较和讨论。

^(131)碘肿瘤细胞核人鼠嵌合单抗肺癌内直接注射后体内的生物学分布

目的研究肺癌瘤内直接注射131I-chTNT后患者体内分布状况。方法经病理组织学确诊的原发性肺癌患者11例,根据CT定位,单次瘤内直接注射131I-chTNT18.5～37MBq/cm3后,多时点测量血、尿放射性。应用HPLC法检测131I-chTNT在体内的稳定性和代谢情况。采用连续显像法估算全身、各主要脏器和肿瘤的放射性,并转换为注射剂量百分率(%ID),以观察131I-chTNT在体内的分布。结果所有11例患者HPLC检测结果显示,注射后24、48、72、96h内血清中131I-chTNT均以原形存在,原形含量达100%。经计算机拟合,血清药-时曲线符合静脉外给药二室模型,T1/2kα(0.89±0.17)h,T1/2β(86.88±25.97)h。游离131I是尿内131I-chTNT的唯一代谢产物,264h累计尿排泄量为注射量的(58.37±17.45)%。瘤内给药后30min,瘤内131I-chTNT量为(51.05±8.41)%ID,瘤/肺比值(T/N)高达(63.87±25.71)。264h时瘤内131I-chTNT残留(3.47±3.27)%ID,T/N为(9.61±11.00)。全身主要器官中,放射性主要集中在肺、肝、心、肾、脾和甲状腺中。结论131I-chTNT瘤内直接注射后在瘤内停留时间较长,有利于肿瘤治疗。