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.

Basic regulatory science behind drug substance and drug product specifications of monoclonal antibodies and other protein therapeutics

In this review,we focus on providing basics and examples for each component of the protein therapeutic specifications to interested pharmacists and biopharmaceutical scientists with a goal to strengthen understanding in regulatory science and compliance.Pharmaceutical specifications comprise a list of important quality attributes for testing,references to use for test procedures,and appropriate acceptance criteria for the tests,and they are set up to ensure that when a drug product is administered to a patient,its intended therapeutic benefits and safety can be rendered appropriately.Conformance of drug substance or drug product to the specifications is achieved by testing an article according to the listed tests and analytical methods and obtaining test results that meet the acceptance criteria.Quality attributes are chosen to be tested based on their quality risk,and consideration should be given to the merit of the analytical methods which are associated with the acceptance criteria of the specifications.Acceptance criteria are set forth primarily based on efficacy and safety profiles,with an increasing attention noted for patient-centric specifications.Discussed in this work are related guidelines that support the biopharmaceutical specification setting,how to set the acceptance criteria,and examples of the quality attributes and the analytical methods from 60 articles and 23 pharmacopeial monographs.Outlooks are also explored on process analytical technologies and other orthogonal tools which are on-trend in biopharmaceutical characterization and quality control.

IMpower210:A phase Ⅲ study of second-line atezolizumab vs. docetaxel in East Asian patients with non-small cell lung cancer

Objective: IMpower210(NCT02813785) explored the efficacy and safety of single-agent atezolizumab vs.docetaxel as second-line treatment for advanced non-small cell lung cancer(NSCLC) in East Asian patients.Methods: Key eligibility criteria for this phase Ⅲ, open-label, randomized study included age ≥18 years;histologically documented advanced NSCLC per the Union for International Cancer Control/American Joint Committee on Cancer staging system(7th edition);Eastern Cooperative Oncology Group performance status of 0 or 1;and disease progression following platinum-based chemotherapy for advanced or metastatic NSCLC. Patients were randomized 2:1 to receive either atezolizumab(1,200 mg) or docetaxel(75 mg/m^(2)). The primary study endpoint was overall survival(OS) in the intention-to-treat(ITT) population with wild-type epidermal growth factor receptor expression(ITT EGFR-WT) and in the overall ITT population.Results: Median OS in the ITT EGFR-WT population(n=467) was 12.3 [95% confidence interval(95% CI),10.3-13.8] months in the atezolizumab arm(n=312) and 9.9(95% CI, 7.8-13.9) months in the docetaxel arm[n=155;stratified hazard ratio(HR), 0.82;95% CI, 0.66-1.03]. Median OS in the overall ITT population was 12.5(95% CI, 10.8-13.8) months with atezolizumab treatment and 11.1(95% CI, 8.4-14.2) months(n=377) with docetaxel treatment(n=188;stratified HR, 0.87;95% CI, 0.71-1.08). Grade 3/4 treatment-related adverse events(TRAEs) occurred in 18.4% of patients in the atezolizumab arm and 50.0% of patients in the docetaxel arm.Conclusions: IMpower210 did not meet its primary efficacy endpoint of OS in the ITT EGFR-WT or overall ITT populations. Atezolizumab was comparatively more tolerable than docetaxel, with a lower incidence of grade3/4 TRAEs.

Safety of teplizumab in patients with high-risk for diabetes mellitus type 1:A systematic review

BACKGROUND The incidence of diabetes mellitus type 1(DM1)has been rising worldwide because of improvements in diagnostic techniques and improved access to care in countries with lower socioeconomic status.A new anti-CD4 antibody,Teplizumab,has been shown to delay the progression of DM1 and is the only medication approved for this indication.However,more information is needed about the safety profile of this drug.AIM To identify the odds ratios(OR)of systems-based adverse effects for Teplizumab when compared to Placebo.METHODS An extensive systematic review was conducted from the inception of the medication until December 31,2023.All clinical trials and studies that evaluated Teplizumab vs placebo were included in the initial review.The study protocol was designed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines guidelines and was registered in PROSPERO(ID:CRD42024496169).Crude OR were generated using RevMan Software version 5.4.RESULTS After screening and review,5 studies were selected to determine the risk of adverse effects of teplizumab compared to placebo.A total of 561 patients were included in the study population.Total adverse effects and system-based adverse effects were studied and reported.We determined that patients receiving Teplizumab had a higher risk of developing gastrointestinal(GI)(OR=1.60,95%CI:1.01-2.52,P=0.04),dermatological(OR=6.33,95%CI:4.05-9.88,P<0.00001)and hematological adverse effects(OR=19.03,95%CI:11.09-32.66,P<0.00001).These patients were also significantly likely to have active Epstein-Barr Virus infection(OR=3.16,95%CI:1.51-6.64,P<0.002).While our data showed that patients receiving Teplizumab did have a higher incidence of total adverse effects vs placebo,this finding did not reach statistical significance(OR=2.25,95%CI:0.80-6.29,P=0.12).CONCLUSION Our systematic review suggests that Teplizumab patients are at risk for significant adverse effects,primarily related to GI,dermatological,and hematological systems.The total adverse effect data is limited as study populations are small.More studies should be conducted on this medication to better inform the target population of potential adverse effects.

Evaluation of teplizumab's efficacy and safety in treatment of type 1 diabetes mellitus:A systematic review and meta-analysis

BACKGROUND Islets of Langerhans beta cells diminish in autoimmune type 1 diabetes mellitus(T1DM).Teplizumab,a humanized anti-CD3 monoclonal antibody,may help T1DM.Its long-term implications on clinical T1DM development,safety,and efficacy are unknown.AIM To assess the effectiveness and safety of teplizumab as a therapeutic intervention for individuals with T1DM.METHODS A systematic search was conducted using four electronic databases(PubMed,Embase,Scopus,and Cochrane Library)to select publications published in peerreviewed journals written in English.The odds ratio(OR)and risk ratio(RR)were calculated,along with their 95%CI.We assessed heterogeneity using Cochrane Q and I2 statistics and the appropriate P value.RESULTS There were 8 randomized controlled trials(RCTs)in the current meta-analysis with a total of 1908 T1DM patients from diverse age cohorts,with 1361 patients receiving Teplizumab and 547 patients receiving a placebo.Teplizumab was found to have a substantial link with a decrease in insulin consumption,with an OR of 4.13(95%CI:1.72 to 9.90).Teplizumab is associated with an improved Cpeptide response(OR 2.49;95%CI:1.62 to 3.81)and a significant change in Glycated haemoglobin A1c(HbA1c)levels in people with type 1 diabetes[OR 1.75(95%CI:1.03 to 2.98)],and it has a RR of 0.71(95%CI:0.53 to 0.95).CONCLUSION In type 1 diabetics,teplizumab decreased insulin consumption,improved C-peptide response,and significantly changed HbA1c levels with negligible side effects.Teplizumab appears to improve glycaemic control and diabetes management with good safety and efficacy.

Efficacy and safety of bamlanivimab in patients with COVID-19:A systematic review and meta-analysis

BACKGROUND Monoclonal antibodies(mAbs)have shown clinical benefits against coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Several studies have reported the use of bamlanivimab as a promising treatment option for COVID-19.AIM To synthesize the latest evidence for the efficacy and safety of bamlanivimab alone in the treatment of adult patients with COVID-19.METHODS A literature search was conducted in PubMed,Cochrane Library,Web of Science,medRxiv,and Google Scholar using“SARS-CoV-2”,“COVID-19”,“LY-CoV555”,and“Bamlanivimab”keywords up to January 25,2023.The quality of included studies was assessed using the Cochrane bias tools.The Comprehensive Meta-Analysis software version 3.0 was used to analyze the data.RESULTS A total of 30 studies involving 47368 patients were included.A significant difference was observed between the bamlanivimab and standard of care/placebo groups in terms of mortality rate[risk ratio(RR)=50,95%confidence interval(CI):0.36-0.70],hospitalization rate(RR=0.51;95%CI:0.39-0.68),and emergency department(ED)visits(RR=0.69;95%CI:0.47-0.99);while the two groups exhibited no significant difference in terms of intensive care unit(ICU)admission(P>0.05).Compared to other mAbs,bamlanivimab was associated with a higher rate of hospitalization(RR=1.44;95%CI:1.07-1.94).However,no significant difference was detected between the bamlanivimab and other mAbs groups in terms of mortality rate,ICU admission,and ED(P>0.05).The incidence of any adverse events was similar between the bamlanivimab and control groups(P>0.05).CONCLUSION Although the results suggest the efficacy and safety of bamlanivimab in COVID-19 patients,further research is required to confirm the efficacy of this drug for the current circulating SARS-CoV-2 variants.

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.

Development and Characterization of Monoclonal Antibody Specific to Nuclear Protein of Avian Influenza Virus Type A

Five monoclonal antibodies（Mabs） to nuclear protein of avain influenza virus（AIV） were developed by syncretizing SP 2/0 and the spleen cells from BALB of mice immuized with H9 subtype AIV. Specificity of these Mabs were identified by immunofluorescent assay（IFA） and enzyme linked immunosorbent assay （ELISA）. These five Mabs which were named as AIV-NP-2C3, AIV-NP-6A5, AIV-NP-3 H9, AIV-NP-7B4, AIV-NP-2H4 could react with all viruses of AIV-H9 strains in tests. The result of Western blotting showed that only the 60 ku protein antigen of AIV-H9 could be recognized by the Mabs but never recognized by New castle disease virus, REV and infectious bursa disease virus. The result of preliminary application showed that avian influenza viruses could be deetected bv Mabs in IFA and ELISA. All these Mabs will probably play important roles in preventing and monitoring avian influenza viruses.

Establishment of Monoclonal Antibody Competitive ELISA Using Monoclonal Antibody Against VP1 Protein of Asia 1 Type Foot-and-Mouth Disease Virus

Using the purified VP1 protein of Asia 1 type foot-and-mouth disease virus as the antigen, the purified monoclonal antibody was labeled by the sodium periodate method and the monoclonal antibody competitive ELISA was established in this study. Ten positive porcine foot-and-mouth disease serums and more than two hundreds negative serum were tested, and the results were the same as the background of samples. The sensitivity test and replicate test indicated that this method was stable and sensitive, which was suitable for monitoring Asia 1 type porcine foot-and-mouth disease virus antibody.

A MONOCLONAL ANTIBODY RECOGNIZING NON DERIVATIVE 13 HYDROXY GIBBERELLINS AND THEIR GLUCOSIDES *

The production and characterization of a monoclonal antibody (MAb AB10) against GA 3 glucoside as well as GA 3 is described. MAb AB10 was derived from an immunogen in which human serum albumin (HSA) was linked to GA 3 at carbon 3. This antibody showed high affinity for GA 3 glucoside as well as for 13 hydroxy gibberellins (GA 1, GA 3, GA 5, etc). The affinity of MAb AB10 for 13 hydroxy GAs was significantly reduced by methylation of the 7 oic acid but not by glycosylation of 3 hydroxyl group. Based on this antibody, both of competitive enzyme linked immunosorbent assays (ELISAs) for GA 3 glucoside and for GA 3 were developed. These two ELISAs displayed linear detection ranges from 0 2 pmol to 20 pmol. Using these assays, the fluctuation of GA 3 like and GA 3 glucoside like substances in the leaves of Rumex japonicus was investigated. The results indicated that the glycosylation of free GAs was connected with leaf senescence and that the function of 6 benzyl amino purine in retarding the leaf senescence was probably related to delaying the process of glycosylation of free GAs.

Preparation and Preliminary Identification of Fluorescein Labeled Monoclonal Antibody against Canine Distemper Virus

[Objective] The aim of the present study was to develop a direct immunofluorescence method for the diagnosis of canine distemper （CD） with FITC-conjugated monoclonal antibodies （FITC-McAb）.[ Metbod] The McAb against CDV, designated as CE3, was purified with protein G and labeled with FITC through agitation method. After purification and identification, the optimal working concentration of FITC-labeled CE3 was determined. Then 61 clinical samples of suspected canine distemper were detected by direct immunofluorescence assay. [ Result] The absorption test, blocking test and specificity test showed that the labeled antibody had high specificity and sensitivity, but didn＇t have cross reaction with canine parvovirus （CPV）, canine parainfluenza virus （CPIV）, canine adenovirus （CAV） and rabies virus （RV）. The optimal working concentration was 1：80. The positive rate of clinical suspected samples was 48%. [ Conclusion] The direct immunofluorescence assay developed in this study was rapid, specific and convenient, and had great significance for the early diagnosis of canine distemper.

Preparation and Identification of Specific Monoclonal Antibody against Porcine Circovirus Type 2

BALB/c mice were immunized using synthetic tandem polypeptide of Cap protein epitope of porcine circovirus type 2 （PCV2） as the antigen. By using lym-phocyte hybridoma technique, a hybridoma cellline stably secreting monoclonal an-tibody against PCV2-rCap protein was successful y obtained and named as 670#. The ascites titer of the obtained monoclonal antibody was 1∶100 000. Western blot results showed that the monoclonal antibody could react with prokaryotical y ex-pressed PET32a-ORF2 recombinant protein, eukaryotical y expressed ORF1-ORF2 tandem protein and PCV2 whole virus celllysate. Indirect EILSA demonstrated that the monoclonal antibody could bind with ORF1-ORF2 tandem protein. Indirect im-munofluorescence assay （IFA） indicated that the monoclonal antibody could identify native PCV2 virus. The preparation of this monoclonal antibody provided technical tools for epitope analysis and molecular diagnosis of PCV2 virus.

A Comparative Study on Detection of the Expression of Alternative Oxidase in Tobacco Callus with the Monoclonal Antibody Against Alternative Oxidase and Antibody Against-Synthetic Polypeptide Antibody

从经过不同温度处理的烟草 (NicotianarusticaL .)愈伤组织中提取并纯化线粒体蛋白 ,分别与交替氧化酶的单克隆抗体和抗合成多肽抗体进行免疫杂交。结果表明 :交替氧化酶的含量随温度的下降而显著上升 ;单克隆抗体的特异性较高于抗合成多肽抗体 ,但后者与交替氧化酶同样有良好的亲和性。因此 ,用合成多肽方法制备的抗体可以用于交替氧化酶的研究中。

山羊地方性鼻内肿瘤病毒MAb的制备及间接ELISA方法的建立

为建立检测山羊地方性鼻内肿瘤病毒(ENTV-2)的间接ELISA方法,本研究以纯化的ENTV-2免疫BALB/c小鼠,采用间接ELISA方法筛选阳性细胞克隆,经3次克隆纯化后获得1株能够稳定分泌ENTV-2特异性单克隆抗体(MAb)的细胞株,命名为6E4,并采用鼠MAb亚类鉴定试剂盒鉴定6E4 MAb的亚类,结果显示,MAb 6E4的亚类为κ链、IgG1亚型。进一步以6E4为检测抗体,经各反应条件的优化建立了检测鼻液样品中ENTV-2的间接ELISA方法,该方法的临界值为0.323。利用该方法检测羊口疮病毒(ORFV)、绵羊肺炎支原体(Movi)、丝状支原体山羊亚种(Mmc)以及纯化的ENTV-2和ENTV-2患病羊鼻液样品,结果显示,除纯化的ENTV-2及ENTV-2患病羊鼻液样品的检测结果呈阳性外,ORFV、Movi、Mmc的检测结果均为阴性,该方法特异性较强。将纯化的ENTV-2(以蛋白浓度换算)2倍倍比稀释(20μg/mL~0.08μg/mL)后,利用建立的间接ELISA方法检测,结果显示,纯化的ENTV-2稀释至0.3125μg/mL时检测结果仍可判定为阳性,该方法敏感性较高。批内、批间重复性试验结果显示,二者变异系数均小于10%,该方法重复性较好。采用荧光定量RT-PCR方法和本实验建立的间接ELISA方法检测109份临床鼻液样品,比较二者之间的符合率,结果显示,该间接ELISA方法与本研究室前期建立的荧光定量RT-PCR的检测结果符合率达94.5%,表明本研究建立的间接ELISA方法可用于ENTV-2感染的临床快速检测。本研究建立的ENTV-2间接ELISA方法为ENT的净化提供了技术手段。

Preparation of Monoclonal Antibody against P65 Protein of Mycoplasma hyopneumoniae

P65 protein, the major immunodominant protein of Mycoplasma hyopneu-moniae （Mhp） exhibiting no cross-reaction with other mycoplasmas, is general y used as a target protein for Mhp detection. In this study, BALB/c mice were immunized with prokaryotical y expressed P65 recombinant protein to prepare monoclonal anti-body. After screening with Mhp whole-cel protein and P65 protein, a specific hy-bridoma cel line, 3G12, was obtained by ELISA. Identification results indicated that the antibody secreted by 3G12 hybridoma cel s could react with P65 protein and Mhp whole-cel protein. According to indirect ELISA assay, 3G12 cel culture super-natant possessed a titer of 1∶12 800 against P65 protein and 1∶3 200 against Mhp whole-cel protein; 3G12 ascites possessed a titer of above 1∶4 000 000 against P65 protein and above 1∶20 000 against Mhp 168 whole-cel protein. After long-term in vitro culture and continuous freezing-thawing, 3G12 cel line could stably secrete antibodies. A monoclonal antibody against P65 protein and Mhp whole-cel protein was successful y obtained in the present study, which provided basis for further in-vestigating the pathogenic mechanism of Mhp and establishing diagnostic methods of Mycoplasmal pneumonia of swine （MPS）.

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.