Establishment and verification of double antibody sandwich ELISA for detection of content of varicella-zoster virus glycoprotein E / 中国生物制品学杂志

@#ObjectiveTo develop and verify a double antibody sandwich ELISA for the quantitative detection of varicellazoster virus(VZV)glycoprotein E(gE).MethodsHybridoma cell lines secreting antibody against VZV-gE stably were screened by mouse hybridoma fusion technology,using VZV whole virus antigen as immunogen.The antibody titer in mouse ascites was detected by indirect ELISA.After purified by Hi Trap2=0.995 6,P=0.000 1)。结论 建立的双抗体夹心ELISA法具有良好的准确性、精密性和特异性，可用于VZV疫苗中g E抗原含量的快速检测。 ObjectiveTo develop and verify a double antibody sandwich ELISA for the quantitative detection of varicellazoster virus(VZV)glycoprotein E(gE).MethodsHybridoma cell lines secreting antibody against VZV-gE stably were screened by mouse hybridoma fusion technology,using VZV whole virus antigen as immunogen.The antibody titer in mouse ascites was detected by indirect ELISA.After purified by Hi Trap(TM)Mabselect(TM)Mabselect(TM)Su Re and Hi Trap(TM)Su Re and Hi Trap(TM)Desalting,monoclonal antibodies(m Abs)were analyzed for the purity by 12%SDS-PAGE,detected for the specificity by Western blot,and identified for the subtype by mouse monoclonal antibody typing kit.Capture antibody and enzyme-labeled antibody were screened by epitope superposition test,which were determined for the working concentrations by chessboard titration(capture antibody concentrations were 0.25,0.5,1,2,5 and 10μg/m L,enzyme-labeled antibody dilutions were 1∶500,1∶1 000,1∶2 000,1∶5 000 and 1∶10 000),and then a double antibody sandwich ELISA(DAS-ELISA)was developed for the detection of VZV-gE content.In addition,the linear range,accuracy,precision and specificity of the method were verified.The gE content in the supernatant of 3 batches of CHO-VZV-gE cells cultured in 7 L bioreactor for 1～14 d were detected by the developed method.ResultsFour positive hybridoma cell lines secreting specific antibodies against VZV-gE stably were obtained and named as m Ab-B2,m Ab-11,K9C7 and K9F4.The antibodies in mouse ascites showed titers of10(TM)Desalting,monoclonal antibodies(m Abs)were analyzed for the purity by 12%SDS-PAGE,detected for the specificity by Western blot,and identified for the subtype by mouse monoclonal antibody typing kit.Capture antibody and enzyme-labeled antibody were screened by epitope superposition test,which were determined for the working concentrations by chessboard titration(capture antibody concentrations were 0.25,0.5,1,2,5 and 10μg/m L,enzyme-labeled antibody dilutions were 1∶500,1∶1 000,1∶2 000,1∶5 000 and 1∶10 000),and then a double antibody sandwich ELISA(DAS-ELISA)was developed for the detection of VZV-gE content.In addition,the linear range,accuracy,precision and specificity of the method were verified.The gE content in the supernatant of 3 batches of CHO-VZV-gE cells cultured in 7 L bioreactor for 1～14 d were detected by the developed method.ResultsFour positive hybridoma cell lines secreting specific antibodies against VZV-gE stably were obtained and named as m Ab-B2,m Ab-11,K9C7 and K9F4.The antibodies in mouse ascites showed titers of106～106～107with purities of about 97%after purification,which all specifically bound to VZV whole virus protein with light chains ofκchain and heavy chains of Ig G_(2b),Ig G_1,Ig G_(2b)and Ig G_(2a)respectively.m Ab-B2 was determined as capture antibody and HPR-labeled m Ab-11 as enzyme-labeled antibody with the optimum working concentrations of 1.5μg/m L and 1∶5 000respectively.The internal reference concentration of gE antigen was in the range of 1.95～1 000 ng/m L,which showed a good linear relationship with A_(450).The four-parameter equation was Y=(0.15-3.99)/[1+(X/67.4)7with purities of about 97%after purification,which all specifically bound to VZV whole virus protein with light chains ofκchain and heavy chains of Ig G_(2b),Ig G_1,Ig G_(2b)and Ig G_(2a)respectively.m Ab-B2 was determined as capture antibody and HPR-labeled m Ab-11 as enzyme-labeled antibody with the optimum working concentrations of 1.5μg/m L and 1∶5 000respectively.The internal reference concentration of gE antigen was in the range of 1.95～1 000 ng/m L,which showed a good linear relationship with A_(450).The four-parameter equation was Y=(0.15-3.99)/[1+(X/67.4)(1.49)]+3.99,and R(1.49)]+3.99,and R2value was 0.999.The recoveries of accuracy verification were 94.9%～114.0%;The coefficients of variation(CVs)of precision verification were all less than 15%.Except CHO-VZV-gE cell culture supernatant,attenuated live varicella vaccine and attenuated live herpes zoster vaccine,the A_(450)of other samples were all less than 0.15 with no cross reaction.The content of gE in the supernatant of three batches CHO-VZV-gE cells increased gradually with the culture time,and was positively related with culture time within 14 days(R2value was 0.999.The recoveries of accuracy verification were 94.9%～114.0%;The coefficients of variation(CVs)of precision verification were all less than 15%.Except CHO-VZV-gE cell culture supernatant,attenuated live varicella vaccine and attenuated live herpes zoster vaccine,the A_(450)of other samples were all less than 0.15 with no cross reaction.The content of gE in the supernatant of three batches CHO-VZV-gE cells increased gradually with the culture time,and was positively related with culture time within 14 days(R2=0.995 6,P=0.000 1).ConclusionThe developed double antibody sandwich ELISA had good accuracy,precision and specificity,which might be used for rapid detection of gE antigen content in VZV vaccine.

Blood glucose related adverse drug reaction of antitumor monoclonal antibodies: a retrospective analysis using Vigibase

Abstract On the increasing prevalence of using mAbs (monoclonal antibodies) in cancer therapy and the severe risk of hyperglycemia, we aimed to analyze the main clinical ADRs of mAbs, with a focus on adverse hyperglycemic events associated with currently clinically used mAbs. mAbs as well as target information were selected from Martinadale book and published articles. Drug approving information was collected from each government website, and ADR statistic data were collected from VigibaseR, comparing with Adverse Event Reporting System of US FDA. Top 10 mAbs were classified within listing in total ADR records, ADRs per year, hyperglycemic ADR records. Vigibase data were updated onto 15 Feb 2019. 20 mAbs were analyzed with 263217 ADR reports, wherein 16751 records on Metabolism and nutrition disorders and 1444 records on Glucose metabolism disorders. The geographic, age, gender distributions and annual ADR report numbers were listed respectively. Of the top 10, Rituximab, Bevacizumab and Nivolumab were on the top 3 in total ADR record and hyperglycemic record. Top 3 record results were similar in Vigibase and FDA database. It is of increasing importance for clinicians to be aware of early detection, patient management, or drug selection strategies when using mAbs, particularly within the high glycemic risk-reported mAbs, to improve the efficacy and tolerability of mAbs regiment and optimize patient outcomes.

Anti-CD3 mAbs induce CD4+FoxP3+Regulatory T( Treg) cells and alleviate acute rejection of the pulmonary al-lografts in mice / 中华胸心血管外科杂志

Objective By using mouse orthotopic lung transplant model, we investigated the immune mechanisms of an-ti-CD3 induced lung allograft protection .Our study intends to further dissect the features of lung transplant immunology and to provide a novel therapeutic insight for the clinical application of anti-CD3 mAbs after lung transplantation.Methods Murine orthotopic allogeneic lung transplants were performed in C57BL/6 wild type(WT) mice using major histocompatibility complex (MHC) fully mismatched BALB/c donors.Syngeneic transplants were also performed in WT C57BL/6 mice using C57BL/6 donors.For immunosuppressive therapy, allograft recipients received 50g dose of anti-CD3 by intraperitoneal injection on days 2, 3, 4, 5, 6 and 9 post-operation(n=4).At day 10, histopathologic characteristics and rejection status of the pulmonary grafts were assessed.The severity of acute rejection was graded by the pathological score , and T cell and neutrophil infiltration in the pulmonary grafts was evaluated by immunohistochemical(IHC) staining for CD3 and myeloperoxidase(MPO) respective-ly.Real-time RT-PCR was performed for FoxP3, IL-17A and IFN-γexpression in the pulmonary grafts.The percentage of FoxP3+Treg in total CD4+T lymphocytes from the recipient spleens was analyzed by FACS.Results 10 days after transplan-tation, histopathologic examination demonstrated that there is no apparent acute rejection observed in the pulmonary isografts , whereas allografts from untreated recipients have marked inflammatory cell infiltration and pulmonary parenchyma lesion .IHC staining for CD3 and MPO showed that the allograft-infiltrating cells of perivascular layers are mainly T lymphocytes , and the cells around the small airways are mostly neutrophils .Anti-CD3 treatment significantly alleviated the acute rejection of pulmo-nary allografts, when compared with the untreated group.Real-time RT-PCR showed that the expression levels of IL-17A and IFN-γin allografts were markedly elevated compared to those in isografts, and anti-CD3 increased the expression of FoxP3, and reduced the expression of IL-17A and IFN-γin the pulmonary allografts.FACS analysis of splenocytes showed that the percent-age of Treg in total CD4+T lymphocytes increased significantly in the anti-CD3 treated allograft recipients, as compared with the isograft and untreated allograft recipients.Conclusion Anti-CD3 mAbs may alleviate acute rejection of the pulmonary al-lografts by promoting FoxP3 expression and Treg development.

Considerations on nonclinical studies for immunotoxicity of monoclonal antibodies / 药物评价研究

Most monoclonal antibodies (mAbs) can induce immune responses.For immunomodulatory mAbs,immunotoxicity is the major toxicity.This article summarizes the characteristics of immunotoxicity,the factors associated with immunotoxicity,and the general considerations of nonclinical studies and evaluations.Before the clinical trials,comprehensive nonclinical studies on immunotoxicityshould be step by step conductedbased on mAbs' characteristics.If needed,some additional studies should be conducted.Attention should be paid to combination of in vivo and in vitro studies,combination of animal species and humanex vivo cells,and multiple approaches for studies.

Reactivation of cutaneous and mucocutaneous tegumentary leishmaniasis in rheumatoid arthritis patients: an emerging problem?

ABSTRACT Rheumatoid arthritis (RA) is a chronic condition that is frequent in patients living in tropical areas exposed to leishmaniasis. RA therapy involves immunosuppressant drugs such as methotrexate (MTX), monoclonal antibodies (mAbs) and prednisone. We report an unusual presentation of cutaneous (CL) or mucocutaneous leishmaniasis (ML) in RA patients from an endemic area of leishmaniasis. A 51-year-old woman noted a cutaneous ulcer on her left ankle during MTX and prednisone RA therapy. Initially diagnosed as a venous stasis ulcer, the aspirate of the injury revealed the presence of Leishmania DNA. A 73-year-old woman presenting non-ulcerated, infiltrated and painful erythematous nodules inside her nostrils while receiving MTX, anti-TNF mAb, and prednisone for RA, had also the aspirate of injuries showing the presence of Leishmania DNA. Both patients healed after the therapy with liposomal amphotericin. The RA therapy has changed to low-dose prednisone, without further reactivation episodes. Both cases suggest that CL or ML can reactivate after administration of an immunosuppressant for RA treatment. Therefore, immunosuppressive treatments for RA should be carefully prescribed in patients from endemic areas or with a history of CL and ML.

Charge-reversal nanoparticles: novel targeted drug delivery carriers

Spurred by significant progress in materials chemistry and drug delivery, charge-reversal nanocarriers are being developed to deliver anticancer formulations in spatial-, temporal- and dosage-controlled approaches. Charge-reversal nanoparticles can release their drug payload in response to specific stimuli that alter the charge on their surface. They can elude clearance from the circulation and be activated by protonation, enzymatic cleavage, or a molecular conformational change. In this review, we discuss the physiological basis for, and recent advances in the design of charge-reversal nanoparticles that are able to control drug biodistribution in response to specific stimuli, endogenous factors (changes in pH, redox gradients, or enzyme concentration) or exogenous factors (light or thermos-stimulation).

Screening of full human anthrax lethal factor neutralizing antibody in transgenic mice / 生物工程学报

Anthrax is a highly lethal infectious disease caused by the spore-forming bacterium Bacillus anthracis. The major virulence factor of B. anthracis consists of protective antigen (PA), lethal factor (LF) and edema factor (EF). PA binds with LF to form lethal toxin (LT), and PA binds with EF to form edema toxin (ET). Antibiotics is hard to work in advanced anthrax infections, because injuries and deaths of the infected are mainly caused by lethal toxin (LT). Thus, the therapeutic neutralizing antibody is the most effective treatment of anthrax. Currently most of the anthrax toxin antibodies are monoclonal antibodies (MAbs) for PA and US FDA has approved ABTHRAX humanized PA monoclonal antibody for the treatment of inhalational anthrax. Once B. anthracis was artificially reconstructed or PA had mutations within recognized neutralization epitopes, anti-PA MAbs would no longer be effective. Therefore, anti-LF MAbs is an important supplement for anthrax treatment. Most of the anti-LF antibodies are murine or chimeric antibodies. By contrast, fully human MAbs can avoid the high immunogenicity of murine antibodies. First, we used LF to immunize the transgenic mice and used fluorescent cell sorting to get antigen-specific memory B cells from transgenic mice spleen lymphocytes. By single cell PCR method, we quickly found two strains of anti-LF MAbs with binding activity, 1D7 and 2B9. Transiently transfected Expi 293F cells to obtain MAbs protein after purification. Both 1D7 and 2B9 efficiently neutralized LT in vitro, and had good synergistic effect when mixed with anti-PA MAbs. In summary, combining the advantages of transgenic mice, fluorescent cell sorting and single-cell PCR methods, this study shows new ideas and methods for the rapid screening of fully human monoclonal antibodies.

An improved ELISA for Detection of Monoclonal Antibodies to Human Hepatocellular Carcinoma / 昆明医科大学学报

Instead of poly—I—lysine, the microtitre plate is in turn pretreated with concentrated sulphuric acid and 100?g/ ml protamine. The living target cells are well attached to the plate. Fixed with 0.025—0.05% glutaraldehyda, the target cells are suitable for screening monoclonal antibodies by ELISA. This assay is specific, sensitive and well reproductive. It is a useful method for screening large scale spent supernatant of hybridomas and ascites at less expense and time. On the other hand, this method can be also used to detect cellular antigens with either MAbs or conventional antibodies.