Development and verification of a reporter gene determination assay for ADCP potency of IgG2 anti-EGFR monoclonal antibody based on DOE / 中国生物制品学杂志

@#Objective To develop and verify a reporter gene assay for the determination of antibody dependent cellular phagocytosis(ADCP)potency of Ig G2 monoclonal antibody(m Ab)against epidermal growth factor receptor(EGFR)by combining Design of Experiment(DOE)and one factor at a time(OFAT).Methods The Jurkat/NFAT-Re/FcγRⅡa stably transformed cell line was used as effector cells,while the A431 cell line as the target cells.The JMP software was used to optimize the seven key factors in the experiment by combining DOE and OFAT analysis,while the ratio of upper and lower asymptotes(D/A)was used as the statistic,and the reporter gene method was developed to evaluate the ADCP potency of Ig G2 anti-EGFR m Ab.The method was verified according to the general chapter<9401>of Chinese Pharmaco-poeia（Ⅲ/Ⅳvolume,2020 edition)and used to determine the biological potency of Ig G2 anti-EGFR m Ab injection.Results After three rounds of experiments,the reporter gene method to evaluate the ADCP potency of Ig G2 anti-EGFR m Ab was developed.The method showed a dose-response relationship and was consistent with the four-parameter regression equa-tion y=(A-D）/[1+(x/C)~B]+D.The range of seven key conditions was determined:the density of effector cells was(1.25-3.75）×10~4 cells/well,the density ratio of effector cells to target cells was 1.0-2.0,the incubation time of target cells was 20-40 min,the incubation time of administration was 15-30 min,the total time was 5.5-6.5 h,and the color time was 5-30 min with luciferase detection system(Bright-Glo)as the color agent.The method had good specificity.Six independent tests were run for the five potency levels,with the correlation coefficient r of 0.994 5 and the linear regression equation slope of 1.02.The relative potency of five potency levels respectively was(62.15±1.38)%,(78.53±2.82)%,(99.12±3.95)%,(123.27±4.59)%and(155.22±7.04)%,the range of relative biases was-2.9%-0.2%,and the range of generalized cross-validation(GCV)was 2.2%-4.6%.The method had good linearity,relative accuracy and precision in the range of 64%-156%.The mean value of the potency of IgG2 anti-EGFR m Ab in three tests was(101.5±2.8)%.Conclusion The reporter gene assay developed in this study can be used to evaluate the ADCP potency of IgG2 anti-EGFR mAb

Status and challenge of vaccine research for Clostridiodes difficile in clinical trials / 中国生物制品学杂志

@#Clostridiodes difficile(C.difficile)is the most common causative agent of antibiotic-associated diarrhea(ADD)in the world. In recent years,with the emergence of highly resistant and virulent strains,the outbreaks of C.difficile infection have occurred around the world. The incidence,recurrence and mortality of C.difficile infection are on the rise worldwide,and bring great challenges to clinical treatment. Pathogenic strains mainly produce two homologous glycosylation toxins A and B,which can cause symptoms ranging from diarrhea to highly lethal toxic megacolon. In view of the malignant consequences caused by C.difficile infection,disease prevention is still an important way worth exploring. Until now there is no approved vaccine against C.difficile. Therefore,this review assessed the status and challenge of clinical trials of vaccine research for C.difficile.

Current advances in chimeric antigen receptor T-cell therapy for refractory/relapsed multiple myeloma / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

multiple myeloma (MM), considered an incurable hematological malignancy, is characterized by its clonal evolution of malignant plasma cells. Although the application of autologous stem cell transplantation (ASCT) and the introduction of novel agents such as immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) have doubled the median overall survival to eight years, relapsed and refractory diseases are still frequent events in the course of MM. To achieve a durable and deep remission, immunotherapy modalities have been developed for relapsed/refractory multiple myeloma (RRMM). Among these approaches, chimeric antigen receptor (CAR) T-cell therapy is the most promising star, based on the results of previous success in B-cell neoplasms. In this immunotherapy, autologous T cells are engineered to express an artificial receptor which targets a tumor-associated antigen and initiates the T-cell killing procedure. Tisagenlecleucel and Axicabtagene, targeting the CD19 antigen, are the two pacesetters of CAR T-cell products. They were approved by the US Food and Drug Administration (FDA) in 2017 for the treatment of acute lymphocytic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL). Their development enabled unparalleled efficacy in combating hematopoietic neoplasms. In this review article, we summarize six promising candidate antigens in MM that can be targeted by CARs and discuss some noteworthy studies of the safety profile of current CAR T-cell therapy.

Current advances in chimeric antigen receptor T-cell therapy for refractory/relapsed multiple myeloma / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Multiple myeloma (MM), considered an incurable hematological malignancy, is characterized by its clonal evolution of malignant plasma cells. Although the application of autologous stem cell transplantation (ASCT) and the introduction of novel agents such as immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) have doubled the median overall survival to eight years, relapsed and refractory diseases are still frequent events in the course of MM. To achieve a durable and deep remission, immunotherapy modalities have been developed for relapsed/refractory multiple myeloma (RRMM). Among these approaches, chimeric antigen receptor (CAR) T-cell therapy is the most promising star, based on the results of previous success in B-cell neoplasms. In this immunotherapy, autologous T cells are engineered to express an artificial receptor which targets a tumor-associated antigen and initiates the T-cell killing procedure. Tisagenlecleucel and Axicabtagene, targeting the CD19 antigen, are the two pacesetters of CAR T-cell products. They were approved by the US Food and Drug Administration (FDA) in 2017 for the treatment of acute lymphocytic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL). Their development enabled unparalleled efficacy in combating hematopoietic neoplasms. In this review article, we summarize six promising candidate antigens in MM that can be targeted by CARs and discuss some noteworthy studies of the safety profile of current CAR T-cell therapy.

Radioimmunotherapy (RIT) in Brain Tumors / 대한핵의학회잡지

Annually, the incidence of brain tumors has slightly increased and also the patient prognosis is still disappointing, especially for high-grade neoplasms. So, researchers seek methods to improve therapeutic index as a critical aim of treatment. One of these new challenging methods is radioimmunotherapy (RIT) that involves recruiting a coupling of radionuclide component with monoclonal antibody (mAb) which are targeted against cell surface tumor–related antigens or antigens of cells within the tumor microenvironment. In the context of cancer care, precision medicine is exemplified by RIT; precision medicine can offer a tailored treatment to meet the needs for treatment of brain tumors. This review aims to discuss the molecular targets used in radioimmunotherapy of brain tumors, available and future radioimmunopharmaceutics, clinical trials of radioimmunotherapy in brain neoplasms, and eventually, conclusion and future perspective of application of radioimmunotherapy in neurooncology cancer care.

Study on antigenic epitope prediction methods of HA protein of H1N1 influenza virus / 中华实验和临床病毒学杂志

Objective@#To investigate the antigenic epitope prediction method of hemagglutinin (HA) protein of influenza A (H1N1) virus.@*Methods@#BALB/c mice were conventionally immunized with influenza H1N1 vaccine. The splenocytes from the immunized mouse were fused with SP2/0 mouse myeloma cell line, and then the antigen-specific monoclonal antibodies (mAbs) were obtained by screening hybridoma supernatants. ELISA blocking test was used to detect the blocking result of each monoclonal antibody, which was labeled by horseradish peroxidase (HRP). The light and heavy chain variable region genes of each antibody were cloned, the amino acid sites of the antibody-binding HA antigen epitope were predicted by computer simulation.@*Results@#Three hybridoma cell lines of stable secreting anti-H1N1 influenza virus HA protein were obtained.Three mAbs were divided into two categories by ELISA blocking tests, which were divided into two categories according to preliminary results of computer simulation.@*Conclusions@#ELISA blocking test and computer simulation prediction can prove each other in predication of the antigenic epitopes of HA protein of H1N1 influenza virus.

Pharmacokinetics of monoclonal antibodies and Fc-fusion proteins

There are many factors that can influence the pharmacokinetics (PK) of a mAb or Fc-fusion molecule with the primary determinant being FcRn-mediated recycling. Through Fab or Fc engineering, IgG-FcRn interaction can be used to generate a variety of therapeutic antibodies with significantly enhanced half-life or ability to remove unwanted antigen from circulation. Glycosylation of a mAb or Fc-fusion protein can have a significant impact on the PK of these molecules. mAb charge can be important and variants with pI values of 1-2 unit difference are likely to impact PK with lower pI values being favorable for a longer half-life. Most mAbs display target mediated drug disposition (TMDD), which can have significant consequences on the study designs of preclinical and clinical studies. The PK of mAb can also be influenced by anti-drug antibody (ADA) response and off-target binding, which require careful consideration during the discovery stage. mAbs are primarily absorbed through the lymphatics via convection and can be conveniently administered by the subcutaneous (sc) route in large doses/volumes with co-formulation of hyaluronidase. The human PK of a mAb can be reasonably estimated using cynomolgus monkey data and allometric scaling methods.

Generation of Monoclonal Antibodies against Non-structural Protein 3AB of Foot-and-Mouth Disease Virus / 中国病毒学·英文版

To identify linear epitopes on the non-structural protein 3AB of foot-and-mouth disease virus (FMDV),BABL/c mice were immunized with the 3AB protein and splenocytes of BALB/c mice were fused with myeloma Sp2/0 cells.Two hybridoma monoclonal antibodies (mAbs) cell lines against the 3AB protein of foot-and-mouth disease virus (FMDV) were obtained,named C6 and E7 respectively.The microneutralization titer was 1∶1024 for mAb C6,and 1∶512 for E7.Both mAbs contain kappa light chains,and were of subclass IgG2b.In order to define the mAbs binding epitopes,the reactivity of these mAbs against FMDV were examined by indirect ELISA.The results showed that both mAbs can react with FMDV,but had no cross-reactivity with Swine Vesicular Disease (SVD) antigens.The titers in abdomen liquor were 1∶5×106 for C6 and 1∶2×106 for E7.In conclusion,the mAbs obtained from this study are specific for the detection of FMDV,can be used for etiological and immunological researches on FMDV,and have potential use in diagnosis and future vaccine designs.

Develope Monoclonal Antibody against Foot-and-mouth Disease Virus A Type / 中国病毒学·英文版

In order to develop an anti-FMDV A Type monoclonal antibo by (mAb),BABL/c mice were immunized with FMDV A type.Monoclonal antibodies (mAbs) 7B11 and 8H4 against Foot-and-mouth disease virus (FMDV) serotype A were produced by fusing SP2/O myeloma cells with splenocyte from the mouse immunized with A/AV88.The microneutralization titer of the mAbs 7B11 and 8H4 were 1024 and 512,respectively.Both mAbs contain kappa light chains,the mAbs were IgG1.In order to define the mAbs binding epitopes,the reactivity of these mAbs against A Type FMDV,were examined using indirect ELISA,the result showed that both mAbs reacted with A Type FMDV.These mAbs may be used for further vaccine studies,diagnostic methods,prophylaxis,etiological and immunological research on FMDV.Characterization of these ncindicated that prepared anti-FMDV A mAbs had no cross-reactivity with Swine Vesicular Disease (SVD) or FMDV O,Asial and C Type antigens.Their titers in abdomen liquor were 1:5×106 and 1:2×106,respectively.7B11 was found to be of subtype IgG1,8H4 was classified as IgG2b subtype.The mAbs prepared in this study,are specific for detection of FMDV serotype A,and is potentially useful for pen-side diagnosis.

Characterization and Diagnostic Use of a Monoclonal Antibody for VP28 Envelope Protein of White Spot Syndrome Virus / 中国病毒学·英文版

The gene encoding the VP28 envelope protein of White spot syndrome virus (WSSV)was cloned into expression vector pET-30a and transformed into the Escherichia coli strain BL21.After induction,the recombinant VP28 (rVP28) protein was purified and then used to immunize Balb/c mice for monoclonal antibody (MAb) production.It was observed by immuno-electron microscopy the MAbs specific to rVP28 could recognize native VP28 target epitopes of WSSV and dot-blot analysis was used to detect natural WSSV infection.Competitive PCR showed that the viral level was approximately 104 copies/mg tissue in the dilution of gill homogenate of WSSV-infected crayfish at the detection limit of dot-blot assay.Our results suggest that dot-blot analysis with anti-rVP28 MAb could rapidly and sensitively detect WSSV at the early stages of WSSV infection.

Monoclonal Antibody S2C4 Neutralizes The Toxicity of Shiga Toxin 2 and Its Variants / 生物化学与生物物理进展

Shiga toxin 2 (Stx2) toxoid produced by formaldehyde treatment of purified toxin was used to immunize BALB/c mice for monoclonal antibody (MAb) production.The neutralizing activities of positive clones against Stx2 were screened by in vitro cytotoxicity assay.The isotype and specificity of resultant clone was determined,and its efficacy to neutralize the activity of purified Stx2 was evaluated by in vitro and in vivo toxicity model.Lastly,its spectrum of activity against Stx2 variants was also accessed by mouse toxicity model.It was demonstrated that one of the 12 positive MAb clones against Stx2,designating $2C4 had neutralizing activity.S2C4 belongs to the immunoglobulin G1 subclass and has a K light chain,and it reacts with the A subunit of Stx2 and does not bind to Stx2 B subunit or to Stx1.S2CA could efficiently neutralize the cytotoxicity of Stx2 to Veto cells and mice.It also protected mice against lethal doses of Stx2 variants challenge including Stx2c and Stx2vha.S2C4 is a promising candidate molecule in preventing the progression of hemolytic-uremic syndrome (HUS) mediated mainly by Stx2 in Stx-producing Escherichia coli(STEC)infection.

Preparation of monoclonal antibodies against ?-amyloid peptide_(1-42) / 西安交通大学学报(医学版)

Objective To prepare a hybridoma secreting stab le monoclonal antibodies against ?-amyloid peptide (A? 1-42) with high titer. Methods By genetic engineering technology, A ? gene was recombined with the MIR of HBcAg to get the A? and HBcAg fusi on protein. Spleen cells from BALB/c mice immunized with A? and HBcAg f usion protein were fused with mouse myeloma cells SP2/0. Results Two strains of hybridomas (1H 7 and 1F 3) secreting stable monoclonal antibodies raised against A? 1-42 were ob tained. The subtypes of A? 1-42 antibodies were IgG 3. C onclusion The A? 1-42 monoclonal antibodies obtained have high titers and specificity.

Production and Characterization of Murine Monoclonal Antibodies ( MAbs ) which Specifically Recognize B-Subunit of Human Chorionic Gonadotropin ( HCG ) / 대한면역학회지

We have constructed several panels of MAbs which specifically recognize B-subunit of HCG (BHCG). Splenocytes from Balb/c mice immunized with B-subunit of HCG were fused with SP2/o-Ag14 myeloma cells by PEG method. Fifteen different hybridorna clones (individually named as mG10.127, mG10.61, mG9.5, mG9.18, rnG9.20, mG6.3, mG6.36, mG6.8, mG7.31, mG7.79, mG9.11, mG9.51.6, mG9.51.12, mH4.17, and mH4.4) were obtained by indirect ELISA screening and three to five successive cloning procedures. The distinct features of these MAbs were determined by specificity, western blot, isotyping, and isoelectrofocusing. All of the MAbs except mG9.20 and mG6.8 specifically bind to BHCG without cross- reaction with B-subunit of LH (BLH). In western blot analysis, all of the MAbs bind to non-denatured form of BHCG suggesting that the MAbs recognize conformation-dependent epitope of BHCG. This new panels of MAbs to BHCG should be useful for developing diagnostic reagent such as pregnancy, choriocarcinoma, Down's syndrome as well as for the fine quantitation of serum or urinary HCG.