Hepatitis B virus reactivation in patients treated with monoclonal antibodies

Hepatitis B virus(HBV)reactivation poses a significant clinical challenge,espe-cially in patients undergoing immunosuppressive therapies,including mono-clonal antibody treatments.This manuscript briefly explores the complex rela-tionship between monoclonal antibody therapy and HBV reactivation,drawing upon current literature and clinical case studies.It delves into the mechanisms underlying this phenomenon,highlighting the importance of risk assessment,monitoring,and prophylactic measures for patients at risk.The manuscript aims to enhance the understanding of HBV reactivation in the context of monoclonal antibody therapy,ultimately facilitating informed clinical decision-making and improved patient care.This paper will also briefly review the definition of HBV activation,assess the risks of reactivation,especially in patients treated with monoclonal antibodies,and consider management for patients with regard to screening,prophylaxis,and treatment.A better understanding of patients at risk can help clinicians provide optimum management to ensure successful patient outcomes and prevent morbidity.

Preparation and application of a novel monoclonal antibody specific for the heat shock protein 60 of Lawsonia intracellularis

Porcine proliferative enteropathy(PPE),an important infectious disease in pig production caused by an obligate intracellular bacterium Lawsonia intracellularis,is commonly associated with diarrhea and reduced weight gain in growing pigs widespread.An accurate method for detecting L.intracellularis is particularly important for preventing and controlling PPE.Heat shock protein 60(Hsp60)is an immunodominant bacterial antigen found in all eukaryotic and prokaryotic organisms.Thus,the purpose of the current investigation was to produce a novel L.intracellularis Hsp60 monoclonal antibody(mAb)useful for immunodiagnostics.Three hybridomas secreted anti-Hsp60 termed 3E5,4E2,and 9G6 were generated,and the titers of ascitic fluids of 3E5,4E2,9G6 were 1:1024000,1:2048000 and 1:2048000,respectively.The Western blotting analysis demonstrated that recombinant Hsp60(rHsp60)was recognized by mAbs 3E5,4E2 and 9G6.Subsequently,analyses of specificity showed all the mAbs were highly specific to L.intracellularis while could not significantly react with other enteric bacteria commonly found in the ileum of pigs,such as Escherichia coli,Salmonella Choleraesuis,Salmonella Typhimurium,and Brachyspira hyodysenteriae.Furthermore,the mAbs were useful for detecting L.intracellularis in the infected monolayer cells and histological sections of the ileum from PPE-affected pigs.Our research will provide a foundation for the development of immunological diagnostic tests.

Monoclonal antibody targeting mu-opioid receptor attenuates morphine tolerance via enhancing morphine-induced receptor endocytosis

Morphine is a frequently used analgesic that activates the mu-opioid receptor(MOR),which has prominent side effects of tolerance.Although the inefficiency of morphine in inducing the endocytosis of MOR underlies the development of morphine tolerance,currently,there is no effective therapy to treat morphine tolerance.In the current study,we aimed to develop a monoclonal antibody(mAb)precisely targeting MOR and to determine its therapeutic efficacy on morphine tolerance and the underlying molecular mechanisms.We successfully prepared a mAb targeting MOR,named 3A5C7,by hybridoma technique using a strategy of deoxyribonucleic acid immunization combined with cell immunization,and identified it as an immunoglobulin G mAb with high specificity and affinity for MOR and binding ability to antigens with spatial conformation.Treatment of two cell lines,HEK293T and SH-SY5Y,with 3A5C7 enhanced morphine-induced MOR endocytosis via a G protein-coupled receptor kinase 2(GRK2)/b-arrestin2-dependent mechanism,as demonstrated by immunofluorescence staining,flow cytometry,Western blotting,coimmunoprecipitation,and small interfering ribonucleic acid(siRNA)-based knockdown.This mAb also allowed MOR recycling from cytoplasm to plasma membrane and attenuated morphine-induced phosphorylation of MOR.We established an in vitro morphine tolerance model using differentiated SH-SY5Y cells induced by retinoic acid.Western blot,enzyme-linked immunosorbent assays,and siRNA-based knockdown revealed that 3A5C7 mAb diminished hyperactivation of adenylate cyclase,the in vitro biomarker of morphine tolerance,via the GRK2/b-arrestin2 pathway.Furthermore,in vivo hotplate test demonstrated that chronic intrathecal administration of 3A5C7 significantly alleviated morphine tolerance in mice,and withdrawal jumping test revealed that both chronic and acute 3A5C7 intrathecal administration attenuated morphine dependence.Finally,intrathecal electroporation of silencing short hairpin RNA illustrated that the in vivo anti-tolerance and anti-dependence efficacy of 3A5C7 was mediated by enhanced morphine-induced MOR endocytosis via GRK2/b-arrestin2 pathway.Collectively,our study provided a therapeutic mAb,3A5C7,targeting MOR to treat morphine tolerance,mediated by enhancing morphine-induced MOR endocytosis.The mAb 3A5C7 demonstrates promising translational value to treat clinical morphine tolerance.

Clinical application of SARS-CoV-2 antibody detection and monoclonal antibody therapies against COVID-19

The purpose of this study was to investigate the clinical application of severe acute respiratory distress syndrome coronavirus-2(SARS-CoV-2)specific antibody detection and anti-SARS-CoV-2 specific monoclonal antibodies(mAbs)in the treatment of coronavirus infectious disease 2019(COVID-19).The dynamic changes of SARS-CoV-2 specific antibodies during COVID-19 were studied.Immunoglobulin M(IgM)appeared earlier and lasted for a short time,while immunoglobulin G(IgG)appeared later and lasted longer.IgM tests can be used for early diagnosis of COVID-19,and IgG tests can be used for late diagnosis of COVID-19 and identification of asymptomatic infected persons.The combination of antibody testing and nucleic acid testing,which complement each other,can improve the diagnosis rate of COVID-19.Monoclonal anti-SARS-CoV-2 specific antibodies can be used to treat hospitalized severe and critically ill patients and non-hospitalized mild to moderate COVID-19 patients.COVID-19 convalescent plasma,highly concentrated immunoglobulin,and anti-SARS-CoV-2 specific mAbs are examples of anti-SARS-CoV-2 antibody products.Due to the continuous emergence of mutated strains of the novel coronavirus,especially omicron,its immune escape ability and infectivity are enhanced,making the effects of authorized products reduced or invalid.Therefore,the optimal application of anti-SARS-CoV-2 antibody products(especially anti-SARS-CoV-2 specific mAbs)is more effective in the treatment of COVID-19 and more conducive to patient recovery.

UV/Vis-based process analytical technology to improve monoclonal antibody and host cell protein separation

Process analytical technology(PAT) is gaining more interest in the biomanufacturing industry because of its potential to improve operational control and compliance through real-time quality assurance.Currently, biopharmaceutical producers mainly monitor chromatographic processes with ultraviolet/visible(UV/Vis) absorbance. However, this measurement has a very limited correlation with purity and quantity. The current study aims to determine the concentration of monoclonal antibody(mAb) and host cell proteins(HCPs) using a build-in UV/Vis monitoring during Protein A affinity chromatography and to optimize the separation conditions for high purity of mAb and minimizing the HCPs content. The eluate was analyzed through in-line UV/Vis at 280 and 410 nm, representing mAb and HCPs concentration,respectively. Each 0.1 column volume(CV) fraction of UV/Vis chromatogram peak area were calculated,and different separation conditions were then compared. The optimum conditions of mAb separation were found as 12 CV loading, elution at pH 3.5, and starting the collection at 0.5 CV point, resulting in high m Ab recovery of 95.92% and additional removal of 49.98% of HCP comparing with whole elution pool. This study concluded that UV/Vis-based in-line monitoring at 280 and 410 nm showed a high potential to optimize and real-time control Protein A affinity chromatography for mAb purification from HCPs.

Therapeutic Implications of Monoclonal Antibody

Background: The coronavirus disease 2019 (COVID-19) pandemic is a distinct public health issue that calls for the quick development of novel treatments and viral detection. Due to their high specificity and reliability, monoclonal antibodies (mAbs) have emerged as useful diagnostic and therapeutic tools for a variety of diseases. As a result, several scientists have jumped right into developing Ab-based assays for the identification of SARS-CoV-2 and Ab drugs for use as COVID-19 therapy agents. Since the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein is essential for viral infection and has a known precise structure, it has become a key target for the creation of therapeutic antibodies. The use of Ab cocktails is anticipated to be a key component of an efficient COVID-19 treatment plan since SARS-CoV-2 is an RNA virus with a high mutation rate, particularly when subjected to the selection pressure of aggressively applied preventive vaccinations and neutralizing Abs. Furthermore, SARS-CoV-2 infection could provoke an overzealous immune response, leading to a cytokine storm that accelerates the onset of a severe disease. Abs to counteract cytokine storms are also actively being researched as COVID-19 therapies. Abs are now used in SARS-CoV-2 detection assays, including immunoglobulin and antigen tests, in addition to their use as medicines. In order to stop the spread of COVID-19, such Ab-based detection tests are essential surveillance tools. In this article, we’ll go over several important ideas related to mAb-based COVID-19 pandemic detection tests and treatments. Objective: To understand the role of hybridoma technology in therapeutic implications. 1) To study the basic concepts and options in hybridoma technology;2) To study the applications of hybridoma technology;3) To explore how hybridoma technology is applied in diagnostic histopathology. Method: For this method generally there is use of mouse or mammals are transfect with the Ags to find out the formation of antibody afterwards isolate the antibody which has been formed after injecting the antigens for a number of weeks. Following are the steps for mAbs: Step 1: In this step immunization of mouse is done;Step 2: Spleen is used for the isolation of B cells;Step 3: Cultivation of cancerous cells;Step 4: Merging of B cells with Myeloma cells;Step 5: This step cell lines are separated;Step 6: in the next step screening the suitable cell lines;Step 7: observation of multiplication in vitro as well as in vivo;Step 8: Harvesting. Discussion: Now a day there are many diseases which has been cured easily at the mean time it’s very difficult to diagnose and get the treatment. Due to advancement of monoclonal antibodies are used in the diagnosis and treatments such as COVID-19, SARS and SARS COV-2. Therefore important part of the monoclonal antibodies are its used in the diagnosis as well as in the treatment tools.

Monoclonal antibodies as therapeutic agents in oncology and antibody gene therapy

，治疗学的代理人主要在肿瘤学被使用的抗体在淋巴瘤，乳癌或颜色由他们的应用说明了表面的癌症。这评论为癌症治疗提供单音的同种细胞的抗体的发展的一个简短历史的图案并且迄今为止为建立最好的试剂总结最重要的临床的数据。改进抗体治疗的反肿瘤功效也讨论策略，包括抗体基因治疗和骨髓的利用作为抗体基因 transporter 导出主要间充质的干细胞。

PRODUCTION AND APPLICATION OF MONOCLONAL ANTIBODY TO POLYAMINE (PREPARATION AND CHARACTERISTICS OF MONOCLONAL ANTIBODIES AGAINST SPERMIDINE)

A monoclonal antibody was first prepared by fusion of mouse myeloma cells (SP2/0-Ag-14) with spleen cells isolated from male BALB/ c mice immunized with spermidine-bovine serum albumin conjugate (SPD- BSA). The hybridoma cell line producing antibody specific for spermidine was cultured in vitro and after i. p. into mice, the ascitic fluid gave suitably high dilution titres (1: 106) by enzyme immunoassay. This monoclonal antibody is of IgG1 class and the bimolecular compleex with molecular weight of 52KD and 27 KD. The monoclonal antibody was clearly specific to spermidine comparing with spermine or putriscine. Monclonal antibody may prove to be useful in the rapid diagnosis and evaluation of patients with cancer.

Analysis of Specific Th1/Th2 Helper Cell Responses and IgG Subtype Antibodies in Anti-CD4 Monoclonal Antibody Treated Mice with Autoimmune Cardiomyopathy

The cytokine repertoire of ADP/ATP carrier-specific humoral immune responses and the cytokine-dependent anti-ADP/ATP carrier antibody IgG subclasses were examined in a cohort of ADP/ATP carrier-immunized BALB/c mice treated with anti-CD4 monoclonal antibody. Eighteen male BALB/c mice （6–8 weeks old） were randomized into 3 groups： dilated cardiomyopathy （DCM） group, DCM-tolerance （Tol） group and control group. The mice in DCM group were immunized with the peptides derived from human ADP/ATP carrier protein for 6 months and mice in the control group were sham-immunized, while the mice in DCM-Tol group were immunized with ADP/ATP carrier protein and anti-CD4 McAb simultaneously. Serum autoantibody against ADP/ATP carrier and IgG subclasses were measured by ELISA, intracellular cytokines IFN-γ and IL-4 of Th cells were moni- tored with flow cytometry, and splenic T cell cytokines IFN-γ, IL-2, IL-4 and IL-6 were detected by using real-time fluorescent quantitative PCR. The results showed that the autoantibody against ADP/ATP carrier was found in all mice in DCM group, and the antibody level, serum IgG1 and IgG2a subclasses, cytokines in T cells and Th cells were all elevated in DCM group, as compared with those in control group （P〈0.01）. On the other hand, in DCM-Tol group, the autoantibody level and contents of all the cytokines were significantly different from those in DCM group （P〈0.01）, and were close to those in control group. And the levels of IgG1, IgG2a, IgG2b and IgG3 were influenced, to varying degrees, by anti-CD4 McAb as compared with those in DCM group. All these four types of IgG subclasses were substantially decreased in DCM-Tol group as compared with DCM group. It is concluded that the treatment with anti-CD4 McAb could prevent the activation of T cells, reverse the abnormal secretion of cytokines and the imbalance between Th1/Th2 cell subsets and abnormal production of autoantibody against ADP/ATP carrier, and eventually avoid myocardial injuries.

THE USE OF ANTI-HUMAN GLIOMA MONOCLONAL ANTIBODIES FOR TARGETING CHEMOTHERAPY OF BRAIN GLIOMAS(PREPARATION AND CYTOTOXIC PROPERTIES OF ANTIBODY-ADRIAMYCIN IMMUNOCONJUGATES)

Immunoconjugates are antibody-drug hybrid molecules which combine the exquisite selectivity or monoclonal antibodies with the potent toxicity of anticancer agents. A monoclonal antibody SZ39 against human brain gliomas was used as a drug carrier. Adriamycin (ADR) was bound covalently to SZ39 to form a SZ39-ADR conjugate. The cytotoxic activity of the SZ39-ADR conjugate was tested in vitro and demonstrated potent and specific killing of cells derived from a human malignant glioma. 50% inhibitory concentration (IC50) for SZ39-ADR to 'target' cells was 8.14×10-9 M. An index of specificity between 'target' and 'non-target' cells was calculated to be 88-fold. These data suggest that the SZ39-ADR may use as a potent and cell type-specific agent and is a likely candidate for the targeting chemotherapy of malignant gliotnas.

PREPARATION AND CHARACTERIZATION OF TWO MONOCLONAL ANTIBODIES AGAINST A_α CHAIN'S C TERMINUS OF FIBRINOGEN

Two monoclonal antibodies (McAbs) against Aα chain's C terminus offibrinogen (Fg) have been prepared and designated SZ-78 and SZ-79. Both theantigens in binding assay and immunoblot analysis showed that the two McAbs recognized the epitopes located in residues 549-560 of the Aαchain. The two McAbs couldaccelerate rate of fibrin polymer assembly both in the purified system and in the humanplasma. From the pictures of transmission electronmicroscope, the average diametersof the fibers increase significantly to an average diameters of 375 nm after incubationwith the McAbs, while it was only 75nm without addition of the McAbs. There were al-so more branchings of fibers with addition of McAbs. These observations demonstratethat the amino acid sequences ofα 549-560 in the COOH terminus of the Aα chain mayplay an important role in the assembly of a fibrin clot, presumably being involved in lat-eral aggregation of protofibrils. The preparation of the McAbs supplies a usuful probe for the investigation of the

Direct technetium-99m labeling of anti-hepatoma monoclonal antibody fragment:a radioimmunoconjugate for hepatocellular carcinoma imaging

AIM To directly radiolabel an anti-hepatomamAb fragment HAb18 F（ab’）2 with 99mTc bystannous-reduced method,and assess thestability,biodistribution and radioimmun-oimaging（RⅡ）.METHODS Immunoreactive fraction wasdetermined according to Lindmo’s method.Ellman’s reagent was used to determine thenumber of thiols in the reduced F（ab’）2.Labelingefficiency and homogeneity were measured bypaper chromatography,sodium dodecylsulphatepolyacrylamide gel electrophoresis（SDS-PAGE）and autoradiography.Challenge assay involvedthe incubation of aliquots of labeled antibody inethylenediaminetetraacetate（ EDTA ）and L-cysteine（L-cys）solutions with different molarratio at 37℃ for 1h,respectively.Investigationsin vivo utilized nude mice bearing humanhepatocellular carcinoma（HHCC）xenograftswith gamma camera imaging and tissuebiodistribution studies at regular intervals.RESULTS The labeling procedure was finishedwithin 1.5 h compared with the'pretinning'method which would take at least 21h.In vitrostudies demonstrated that the radiolabeled mAbfragment was homogeneous and retained itsimmunoreactivity.Challenge studies indicatedthat 99mTc-labeled HAb18 F（ab’）2 in EDTA is morestable than in L-cys.Imaging and biodistribution showed a significant tumor uptake at 24 h post-injection of 99mTc-labeled HAb18 F（ab’）2.Theblood,kidney,liver and tumor uptakes at 24hwere 0.56±0.09,56.45±11.36,1.43±0.27 and6.57±3.01（%ID/g）,respectively.CONCLUSION 99mTc-HAb18 F（ab’）2 conjugateprepared by this direct method appears to be aneffective way to detect hepatoma in nude micemodel.

Preparation and activity of conjugate of monoclonal antibody HAb18 against hepatoma F( ab′ )_2 fragment and staphylococcal enterotoxin A

AIM To prepare the conjugate of staphylococcal enterotoxin A (SEA) protein which is a bacterial SAg and the F(ab')2 fragment of mAb HAbl8 against human hepatocellular carcinoma (HCC), and identify its activity in order to use SAg in the targeting therapy of HCC.METHODS MAb HAbl8 was extracted from the abdominal dropsy of Balb/ c mice, and was purified through chromatography column SP-40HR with Fast protein liquid chromatography (FPLC) system. The F(ab')2 fragment of mAb HAb18 was prepared by papainic digestion method. The conjugate of mAb HAb18 F(ab')2fragment and SEA was prepared with chemical conjugating reagent N-succinimidyl-3-( 2-pyridyldithio) propionate (SPDP) and purified through chromatography column Superose 12with FPLC system. The molecular mass and purity of each collected peak were identified with SDS-PAGE assay. The protein content was assayed by Lowry's method. The antibody activity of HAb18 F (ab')2 against HCC in the conjugate was identified by indirect immunocytochemical ABC method, and the activity of SEA in the conjugate to activate peripheral blood mononuclear cells (PBMC) was identified with MTT assay.RESULTS The lgG mAb HAb18 was extracted,and purified successfully. Immunocytochemical staining demonstrated that it reacted with most of HHCC cells of human HCC cell line. There were two peaks in the process of purification of the prepared HAb18 F(ab)2-SEA conjugate. SDS-PAGE assay demonstrated that the molecular mass of the first peak was about 130 ku, and the second peak was the mixture of about 45 ku and a little 100 ku proteins. The immunocytochemical staining was similar in HAb18 F (ab ')2-SEAconjugate and HAb18 F (ab ')2, i.e., thecytoplasm and/or cell membranes of most HHCC cells were positively stained. The MTT assay showed that the optical absorbance (A) value at 490 nm of HAb18 F (ab')2-SEA conjugate was 0.182 ± 0.012, that of negative control was 0.033± 0.009, and there was significant difference between them ( P < 0.05).CONCLUSION SPDP is a good proteinconjugating reagent and can be used in preparing protein conjugate. The conjugate of mAb HAb18F(ab')2 fragment and SEA protein was preparedsuccessfully in present study and can be used in the experimental study of HCC targeting therapy with the conjugate of SAg and anti-HCC mAbs or their fragments.

Role of P-selectin and anti-P-selectin monoclonal antibody in apoptosis during hepatic/renal ischemia-reperfusion injury

AIM To evaluale the potential role of P-selectinand anti-P-selectin monoclonal antibody(mAb)in apoptosis during hepatic/renal ischemia-reperfusion injury.METHODS Plasma P-selectin level,hepatic/renal P-selectin expression and cell apoptosiswere detected in rat model of hepatic/ renalischemia-reperfusion injury.ELISA,immunohist-ochemistry and TUNEL were used.Someischemia-reperfusion rats were treated with anti-P-selectin mAb.RESULTS Hepatic/renal function insuffic-iency,up-regulated expression of P-selectin inplasma and hepatic/renal tissue,hepatic/renalhistopathological damages and cell apoptosiswere found in rats with hepatic/renal ischemia-reperfusion injury,while these changes becameless conspicuous in animals treated with anti-P-selectin mAb.CONCLUSION P-selectin might mediateneutrophil infiltration and cell apoptosis andcontribute to hepatic/renal ischemia-reperfusioninjury,anti-P-selectin mAb might be an efficientapproach for the prevention and treatment ofhepatic/renal ischemia-reperfusion injury.

Preparation and application of monoclonal antibodies against hepatitis C virus nonstructural proteins

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Monoclonal antibody-based serological detection of Citrus yellow vein clearing virus in citrus groves

Citrus yellow vein clearing virus （CYVCV） is considered as the causal agent of Citrus yellow vein clearing disease and belongs to the genus Mandarivirus in the family Alphaflexiviridae. Capsid protein （CP） of CYVCV Chongqing isolate （CYVCV- CQ） was produced using a prokaryotic expression system and used as the immunogen for monoclonal antibody （MAb） production. Four highly specific and sensitive murine MAbs and one polyclonal antibody were prepared in this study. Titers of the four MAbs in ascites fluids ranged from 10-6 to 10-7 as determined by indirect enzyme-linked immunosorbent assay （ELISA）. Three serological assays, including dot enzyme-linked immunosorbent assay （dot-ELISA）, tissue blot-ELISA, and double-antibody sandwich （DAS）-ELISA, were developed for quick and reliable detections of CYVCV in citrus samples. The developed dot-ELISA and DAS-ELISA methods could detect CYVCV in the infected citrus leaf crude extracts diluted at 1：2 560 and 1：10 240 （w/v, g mL^-1）, respectively. The detection result of 125 citrus leaf samples collected from citrus groves in Yunnan Province and Chongqing Municipality of China showed that approximately 36% samples were positive for CYVCV. This virus was, however, not＇detected in any sample collected from Zhejiang or Jiangxi Province, China.

Development and detection application of monoclonal antibodies against Zucchini yellow mosaic virus

Aphid-borne Zucchini yellow mosaic virus （ZYMV） is one of the most economically important viruses of cucurbitaceous plants. To survey and control this virus, it is necessary to develop an efficient detection technique. Using purified ZYMV virion and the conventional hybridoma technology, three hybridoma cell lines （16A11, 5A7 and 3B8） secreting monoclonal antibodies （MAbs） against ZYMV Zhejiang isolate were obtained. The working titers of the ascitic fluids secreted by the three hybridoma cell lines were up to 10^-7 by indirect enzyme-linked immunosorbent assay （ELISA）. All MAbs were isotyped as IgG1, kappa light chain. Western blot analysis indicated that the MAb 3B8 could specifically react with the coat protein of ZYMV while MAbs 5A7 and 16A11 reacted strongly with a protein of approximately 51 kDa from the ZYMV-infected leaf tissues. According to this molecular weight, we consider this reactive protein As likely to be the HC-Pro protein. Using these three MAbs, we have now developed five detection assays, i.e., antigen-coated-plate ELISA （ACP-ELISA）, dot-ELISA, tissue blot-ELISA, double-antibody sandwich ELISA （DAS-ELISA）, and immunocapture-RT-PCR （IC-RT-PCR）, for the sensitive, specific, and easy detection of ZYMV. The sensitivity test revealed that ZYMV could be readily detected respectively by ACP-ELISA, dot-ELISA, DAS-ELISA and IC-RT-PCR in 1：163840, 1：2560, 1：327680 and 1：1 310720 （w/v, g mL-1） diluted crude extracts from the ZYMV-infected plants. We demonstrated in this study that the dot-ELISA could also be used to detect ZYMV in individual viruliferous aphids. A total of 275 cucurbitaceous plant samples collected from the Zhejiang, Jiangsu, Shandong and Hainan provinces, China, were screened for the presence of ZYMV with the described assays. Our results showed that 163 of the 275 samples （59%） were infected with ZYMV. This finding indicates that ZYMV As now widely present in cucurbitaceous crops in China. RT-PCR followed by DNA sequencing and sequence analyses confirmed the accuracy of the five assays. We consider that these detection assays can significantly benefit the control of ZYMV in China.

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.

Production and Characterization of Anti-estrone Monoclonal Antibody

Objective Determination of estrone (E1) levels has a significant meaning in evaluating physiological effect and diagnosing some diseases. In order to detect free E1 in biological fluids, a monoclonal antibody specific for E1 was prepared after the complete antigen of E1 was synthesized. The purified monoclonal antibody was fully characterized for later immunoassay. Methods 3-O-carboxymethyl ether derivative of E1 was synthesized and in turn coupled to bovine serum albumin (BSA) to form complete antigen E1-BSA. A monoclonal antibody (McAb) specific for E1 was produced both in vitro and in vivo by a hybridoma anti-E1. Anti-E1 was prepared by fusion of SP2/0 murine myeloma cells with spleen cells isolated from immunized BALB/c mouse. The McAb was characterized by enzyme-linked immunosorbent assay (ELISA), SDS-PAGE and Western-blotting. The specificity of the immunoassay was investigated by determining the cross-reactions of E1 analogs when free E1 was detected by competitive indirect enzyme-linked immunosorbent assay (CI-ELISA). Results Analysis revealed that anti-E1 McAb (E1-McAb) was of the IgG1 type, the molecular weight of E1-McAb was 164 000 daltons. The affinity constant of E1-McAb with coated complete antigen was 8.2108L/mol. The linear range for free E1 determined by CI-ELISA was 10pg/mL^10ng/mL. The detection limit was 21.4 pg/mL (defined as twice the standard deviation of the blank). Conclusion The CI-ELISA developed with E1-McAb was both sensitive and specific. The prepared E1-McAb can be used in some immunoassays.

Preparation of monoclonal antibody against human KIAA0100 protein and Northern blot analysis of human KIAA0100 gene

Monoclonal antibodies(MAbs) are important tools for the study of proteins′ function and structure. But there has been no report on the preparation of MAbs against human KIAA0100 protein up to date. Here, first, we generated the mouse MAb against human KIAA0100 protein using purified recombinant 6×Histidinc(6×His)-tagged human KIAA0100 protein segment(1557–2234) as an antigen; then, the m RNA expression of human KIAA0100 gene was detected in U937 cells using Northern blot analysis. The results showed that the mouse MAb against human KIAA0100 protein could sensitively recognize the human KIAA0100 protein using Western blot analysis and immunocytochemistry analysis. Besides, Western blot analysis revealed that human KIAA0100 gene possibly encoded two different protein products(254 k Da and < 250 k Da) in U937 cells. Moreover,Northern blot analysis confirmed that human KIAA0100 gene might produced two different m RNA products(6000–10000 bp and 5000–6000 bp) in U937 cells. The results provide a basis for large-scale production of the MAb against human KIAA0100 protein, which will be useful for the study of human KIAA0100 protein′s function/structure and MAb-targeted drugs in the future.