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.

Tratamiento farmacológico del estrabismo / Pharmacological treatment of strabismus

La cirugía de la musculatura extraocular ha sido el estándar de atención para tratamiento quirúrgico del estrabismo por más de un siglo. A pesar del gran desarrollo técnico de la cirugía de estrabismo en la actualidad, la utilización de microscopio quirúrgico, el diseño novedoso del instrumental quirúrgico, la calidad de la sutura no reabsorbible; los avances en equipamiento y fármacos anestésicos, la misma no está exenta de complicaciones quirúrgicas, además del tiempo de recuperación que necesita el paciente para reincorporarse a sus actividades sociales, han propiciado una búsqueda permanente del tratamiento farmacológico para el estrabismo. El objetivo de esta revisión bibliográfica es analizar las distintas alternativas farmacológicas disponibles como tratamiento del estrabismo. Para su confección se consultó textos completos y artículos en idiomas español e inglés, disponible en algunas bases de datos. Concluimos que aunque se han estudiado numerosos fármacos, la toxina botulínica que es la más conocida y utilizada mundialmente, seguida de la bupivacaína. Encontramos otros como la IGF I y II (Insuline Growing Factor), capaces de generar un efecto de reforzamiento de la actividad muscular. Y otros que "debilitan" la musculatura extraocular, incluyen la mAb35-Rubicina, BMP4 (Proteína morfogénica ósea). Se continúa su investigación en la actualidad(AU)

Extraocular musculature surgery has been the standard of care for surgical treatment of strabismus for more than a century. Despite the great technical development of strabismus surgery today, the use of a surgical microscope, the novel design of surgical instruments, the quality of the non-absorbable suture; Advances in anesthetic equipment and drugs, it is not exempt from surgical complications, in addition to the recovery time that the patient needs to return to their social activities, have led to a permanent search for pharmacological treatment for strabismus. The objective of this bibliographic review is to analyze the different pharmacological alternatives available as a treatment for strabismus. For its preparation, full texts and articles in Spanish and English languages were consulted, available in some databases. We conclude that although numerous drugs have been studied, botulinum toxin, which is the best known and used worldwide, followed by bupivacaine. We find others such as IGF I and II (Insuline Growing Factor), capable of generating an effect of reinforcing muscle activity. And others that "weaken" MOE include mAb35-Rubicin, BMP4 (Bone Morphogenic Protein). His research is continuing today(AU)

A general view of CD33⁺ leukemic stem cells and CAR-T cells as interesting targets in acute myeloblatsic leukemia therapy

Acute myeloblastic leukemia (AML) is the most frequent acute leukemia in adulthood with very poor overall survival rates. In the past few decades, significant progresses had led to the findings of new therapeutic approaches and the better understanding of the molecular complexity of this hematologic malignancy. Leukemic stem cells (LSCs) play a key role in the initiation, progression, regression, and drug resistance of different types of leukemia. The cellular and molecular characteristics of LSCs and their mechanism in the development of leukemia had not yet been specified. Therefore, determining their cellular and molecular characteristics and creating new approaches for targeted therapy of LSCs is crucial for the future of leukemia research. For this reason, the recognition of surface maker targets on the cell surface of LSCs has attracted much attention. CD33 has been detected on blasts in most AML patients, making them an interesting target for AML therapy. Genetic engineering of T cells with chimeric antigen receptor (CAR-T cell therapy) is a novel therapeutic strategy. It extends the range of antigens available for use in adoptive T-cell immunotherapy. This review will focus on CAR-T cell approaches as well as monoclonal antibody (mAB)-based therapy, the two antibody-based therapies utilized in AML treatment.

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.

Growth suppression of colorectal cancer expressing S492R EGFR by monoclonal antibody CH12 / 医学前沿

Colorectal cancer (CRC) is a common malignant tumor in the digestive tract, and 30%-85% of CRCs express epidermal growth factor receptors (EGFRs). Recently, treatments using cetuximab, also named C225, an anti-EGFR monoclonal antibody, for CRC have been demonstrated to cause an S492R mutation in EGFR. However, little is known about the biological function of S492R EGFR. Therefore, we attempted to elucidate its biological function in CRC cells and explore new treatment strategies for this mutant form. Our study indicated that EGFR and S492R EGFR accelerate the growth of CRC cells in vitro and in vivo and monoclonal antibody CH12, which specifically recognizes an EGFR tumor-specific epitope, can bind efficiently to S492R EGFR. Furthermore, mAb CH12 showed significantly stronger growth suppression activities and induced a more potent antibody-dependent cellular cytotoxicity effect on CRC cells bearing S492R EGFR than mAb C225. mAb CH12 obviously suppressed the growth of CRC xenografts with S492R EGFR mutations in vivo. Thus, mAb CH12 may be a promising therapeutic agent in treating patients with CRC bearing an S492R EGFR mutation.

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.

Development of a Novel Optimization and Validation Method Based on DOE for the ADCC Potency of Anti-PD-1/PD-L1 Monoclonal Antibodies Using Reporter Genes / 中国药学杂志

OBJECTIVE: To develop a novel optimization and validation method based on design of experiment(DOE) for the antibody-dependent cell-mediated cytotoxicity (ADCC) potency of anti-programmed cell death 1 and anti-programmed cell death-ligand 1 (PD-1/PD-L1) monoclonal antibodies using reporter genes. METHODS: Jurkat-hFcγRIIIa-NFAT transgenic cell line was used as effector cells, 293FT-PD-1 cell line and CHO-PD-L1 cell line were used as target cells, respectively. The ADCC potency for anti-PD-1/PD-L1 monoclonal antibodies was detected with Luciferase detection system (BrightGloTM Luciferase Assay system), then the method was optimized and validated based on DOE. RESULTS: The anti-PD-1/PD-L1 monoclonal antibodies showed a dose-response relationship and the determination result complied with the following four-parameter equation: y=(A-D)/+D. The method was optimized and the testing parameters were determined as follows: the working concentration of anti-PD-1 monoclonal antibody was 10 000 ng•mL-1 to 4.833 ng•mL-1 and that of anti-PD-L1 was 2 000 ng•mL-1 to 0.488 ng•mL-1, the ratio of effector cells and target cells for anti-PD-1/PD-L1 monoclonal antibodies were 6:1 and 3:1, and the induction time for both of these antibodies was 20 h. The method possessed good specificity. The recovery rate test samples in the four different dilution groups were determined for 3 times, and the results showed that the relative potencies of anti-PD-1 monoclonal antibody were (51.74±2.22)%, (77.12±3.14)%, (118.71±2.83)% and (156.20±12.99)%, and the recoveries of which were (103.49±4.44)%, (102.83±4.19)%, (94.96±2.26)% and (104.14±8.66)%, respectively. While as for anti-PD-L1 monoclonal antibody, the relative potencies were (54.32±4.75)%, (75.24±4.25)%, (127.40±2.43)%, (156.82±3.27)% and the recoveries were (108.64±9.51)%, (100.33±5.67)%, (101.92±1.94)% and (104.55±2.18)%, respectively. The RSDs of the above results were all less than 10%. CONCLUSION: A novel optimization and validation method based on DOE for detecting ADCC potency of anti-PD-1/PD-L1 mAb is successfully developed. This detecting method based on reporter gene shows high specificity, good reproducibility and high accuracy, and might be used in the evaluation of ADCC potency of anti-PD-1/PD-L1 mAb.

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.

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.

Treatment and outcomes: medical and surgical treatment for intestinal Behçet's disease

Behçet's disease (BD) is a chronic relapsing disease involving multiple organ systems. BD is characterized clinically by oral and genital aphthae, cutaneous lesions, and ophthalmological, neurological, and/or gastrointestinal manifestations. It is widely recognized that the presence of intestinal lesions may be a poor prognostic factor in intestinal BD, increasing the risk of surgery and decreasing the quality of life. Despite this, the management of intestinal BD has not been standardized. Empirical therapies including 5-aminosalicylic acid and corticosteroids have been used anecdotally to treat intestinal BD, but recent studies have provided evidence for the efficacy of anti-tumor necrosis factor α monoclonal antibodies. The development of agents targeting tumor necrosis factor α continues, it seems likely that they will change the therapeutic strategy and clinical outcomes of intestinal BD and inflammatory bowel disease. Monitoring disease activity such as endoscopic evaluation will become more important to obtain better outcomes. Here, we review current and future perspectives in the treatment and outcomes of intestinal BD.

Cluster endophthalmitis following multiple intravitreal bevacizumab injections from a single use vial.

The risk of endophthalmitis is always a concern when an intraocular procedure is performed. Intravitreal injection is a frequently used method for therapeutic management of many diseases, affecting the posterior segment of the eye. Hence, it is important to assess the risk of complications, especially endophthalmitis. Most studies conducted concentrate on risk assessment from single use from single drug vial. The present article reports the occurrence of cluster endophthalmitis following multiple intravitreal bevacizumab injections from a single vial. Intravitreal injection of bevacizumab was administered to eight eyes of eight patients. Administered dose was prepared from single 4-ml vial of bevacizumab and was injected in the eye, after patient preparation and under aseptic conditions. The procedure was repeated for the remaining patients, thereby imparting multiple pricks in the same vial. Four of the eight patients reported to the hospital on the 3rd day after injection with complaints of pain, watering, and diminution of vision. Two patients reported the following day with similar complaints. Two patients who did not report by the 4th day were contacted and recalled for an examination. All the patients were thoroughly examined using slit lamp biomicroscopy and indirect ophthalmoscopy. Six out of eight were clinically diagnosed to have endophthalmitis and were administered intravitreal antibiotics. The present report highlights possibility of microbial contamination of the drug vial or during compounding process. However, from the present incident, we are encouraged to stay vigilant and wary of contamination.

Development of quality control methods of recombinant anti-EBOV antibodies / 中国药学杂志

OBJECTIVE: To establish quality control methods for recombinant anti-EBOV mAbs which are comprised by three anti-EBOV glycoprotein mAbs. METHODS: The binding-activity of recombinant humanized anti-EBOV mAbs to EBOV glycoprotein was evaluated by ELISA. Peptide map by LC-MS was used in the identification tests. Purity was analyzed by CE-SDS and SEC-HPLC. iCIEF was performed to measure the PI value and the charge heterogeneity. 2AB was labeled on the released glycan, and was analyzed by NP-HPLC and mass spectrometry. The concentration of polysorbate 20 was tested by HPLC. RESULTS: The EC50s of recombinant anti-EBOV mAbs were (12.53±1.62), (11.10±0.62) and (6.09±0.35) ng·mL-1, respectively. The theoretical sequence coverage rates of three mAbs were all above 95%. The main peak area percentages shown by non-reduced CE-SDS were (94.41±0.05)%, (95.58±0.17)% and (96.11±0.05)%. The peak area percentages of both heavy and light chain shown by reduced CE-SDS were (98.19±0.06)%, (97.97±0.03)% and (98.57±0.03)%. The main peak area percentages shown by SE-HPLC were (99.59±0.01)%, (99.56±0.01)% and (99.74±0.01)%. The isoelectric points of the main peak shown by iCIEF were (8.70±0.01),(8.26±0.01) and (8.85±0.01). The concentrations of polysorbate 20 were (0.34±0.00),(0.35±0.00) and (0.35±0.01) μg·mL-1, respectively. The glycan mapping analysis was relatively sensitive, and the percentage of fucosylated N linked glycan was less than 0.5%. CONCLUSION: Up-to-date quality control methods for recombinant anti-EBOV mAbs are established in this study, which may be used to ensure the safety, effectiveness and quality controllability of the product. The methods can provide technical assists to Ebola outbreak and be a reference of the quality control of other domestic cocktail monoclonal antibody products.

An Analysis of the Diversification of Cell Temperature of Photothermal Effects of Gold Nanorods Coated with mAb-EGFR on FADU Human Pharyngeal Squamous Cell Lines and Non-tumor Cells 293 T Cell Line / 听力学及言语疾病杂志

Objective To study the cell temperature on photothermal effects of gold nanorods coated with mAb-EGFR targeted on FADU human pharyngeal squamous cell lines and non- tumor cells(293T cell line) .Meth‐ods CTAB gold nanorods were synthesized to complete the functional modifications of EGFR monoclonal antibody , with a UV spectrophotometer and electron microscopy characterization .The cultured FADU hypopharyngeal cells and non-tumor cells 293 T cell lines were expressed by western blot EGFR statutory comparison of two cell lines , cells to swallow the gold nanorods were observed .Cell apoptosis was observed by Annexin-V -FLUOS and pro‐pidium iodide .Then we set different doses of gold nanoparticles concentration (15% ,25 % ,and 35% ) .After 6 minutes'near-infrared laser irradiation (λ=808 nm) ,the temperature was recorded once every minute ,and cell viability was detected by XTT assay .Results After six minutes'near -infrared laser irradiation ,the cell tempera‐ture was 41 ℃ ~43 ℃ ,with 15% ~25 % of gold nanorods .The cell killing effects on hypopharyngeal were signifi‐cant .The 293T cells did not show any damaging effects (P<0 .05) ,whereas the concentration of gold nanoparticles in 35% of hypopharyngeal FADU cells and 293T cells had significant cytotoxicity (P<0 .05) .Conclusion There were significant cell killing effects with 15% ~25% gold nanorods coated with mAb-EGFR in the near -infrared laser irradiation six minutes (Cell temperatures of both cell lines were 41 ℃ ~43 ℃)on hypopharyngeal FADU cell but not on non-tumor cells .

An approach for conjugation of 177Lu- DOTA-SCN- Rituximab (BioSim) & its evaluation for radioimmunotherapy of relapsed & refractory B-cell non Hodgkins lymphoma patients.

Background & objectives: The prerequisite of radioimmunotherapy is stable binding of a radionuclide to monoclonal antibodies, which are specific to the tumour-associated antigen. Most B-cell lymphomas express CD20 antigen on the surface of the tumour cells, making it a suitable target for therapeutic radioactive monoclonal antibodies. In the present study, the immunoconjugate of biosimilar Rituximab (Reditux™) and macrocyclic chelator, p-SCN-Bz-DOTA, was prepared and radiolabelled with Lutetium-177 followed by quality control procedures. Methods: Rituximab(BioSim) was desalted with sodium bicarbonate (0.1M, pH 9.0) and incubated with DOTA-SCN (1:50). The effectiveness of the conjugation was evaluated by determining the number of chelators per antibody molecule. This conjugate was radiolabelled with Lutetium-177 and purified using PD10 column. The quality control parameters like pH, clarity, radiochemical purity, in vitro stability and sterility were studied. Immunoreactivity of 177Lu-DOTA-Rituximab (BioSim) was assessed using RAMOS cells. The radioimmunoconjugate (RIC) after stringent quality assurance was injected in three patients and the biodistribution profile was analysed. Results: An average of 4.25 ± 1.04 p-SCN-Bz-DOTA molecules could be randomly conjugated to a single molecule of Rituximab (BioSim).The radiochemical purity of the labelled antibody was >95 per cent with preserved affinity for CD20 antigen. The final preparation was stable up to about 120 h when tested under different conditions. A favourable biodistribution profile was observed with liver showing the maximum uptake of the RIC. Interpretation & conclusions: A favourable radiochemical purity, stability and biodistribution of the radiolabelled immunoconjugate indicate that clinical trials for evaluation of toxicity and efficacy of 177Lu-DOTA-antiCD20 antibody-Rituximab (BioSim) in patients of relapsed and refractory non Hodgkin’s lymphoma can be considered.

Development of full human monoclonal Ab to human TRAIL-Rs for tumor therapy / 实用肿瘤学杂志

Monoclonal antibodies(mAbs)to human TRAIL receptors(TRAIL-Rs)have been developed in tumor targeted therapy and currently used in clinical Ⅰ~Ⅳtrials.MAbs can bind death-receptors(TRAIL-R1 and TRAIL-R2)and then results in formation of the death inducing signaling complex (DISC)and apoptosis of tumor cells.TRAIL -Rs mAbs have become one of the research and development hotspots of anti -tumor drugs.These mAbs have achieved remarkable results in combination with radio -or chemo-therapy drugs or oth-er agents and immunotherapy in the treatment of tumor and offer a new therapeutic strategy for clinical tumor treatment.

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.

A novel mycotoxin purification system using magnetic nanoparticles for the recovery of aflatoxin B1 and zearalenone from feed

In this study, we developed a novel tool for purifying two mycotoxins, aflatoxin B1 (AFB1) and zearalenone (ZEN), in feed. This system utilized monoclonal antibodies (mAbs) against AFB1 and ZEN, and magnetic nanoparticles (MNPs). Among ten MNPs with different diameters and functional groups, a 100-nm diameter MNP (fMA) conjugated to an amine group (-NH2) was found to be optimum for coupling with mAbs. The optimal mAb concentrations for coupling to the fMA along with mycotoxin purification capacities of the fMA-mAb conjugates (fMA-AFB1 and fMA-ZEN) were determined. A comparison of mean recovery rates (from corn and product X feed) between the fMA-mAb conjugates and immunoaffinity columns (IAC-AFB1 and IAC-ZEN) showed that the rate for fMA-AFB1 (90~92% and 81~88%) was higher (p > 0.05) than that of IAC-AFB1 (81~84% and 72~78%) for AFB1 (5, 10, 15 ng/mL), and the rate for fMA-ZEN (99~100% and 92~94%) was significantly higher (p 30 min). This study suggests that the novel purification system we developed would be a useful tool for monitoring and regulating mycotoxin contamination in feed, and replace IAC methods.

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.

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.