Objective To prepare monoclonal antibodies against bovine CD4 and identify their basic biological characteristics. Methods Recombinant bovine CD4 (rHis-BoCD4 and rGST-BoCD4) was successfully expressed and purified by constructing a prokaryotic plasmid of bovine CD4 gene. The bovine CD4 monoclonal antibody was produced using hybridoma technology. The subtype and potency of the monoclonal antibody were identified and analyzed by ELISA, while specificity was analyzed through indirect immunofluorescence assay (IFA) and Western-blot. Results Four hybridoma cell lines, namely, 1H4, 6A10, 3F9 and 4G10, stably secreting monoclonal antibodies against BoCD4 were successfully obtained. The subclasses of the monoclonal antibodies subclass 6A10 was IgG2b and the rest of the monoclonal antibodies were of IgM type. Western-blot results showed that the four anti-bovine CD4 mAb strains were able to specifically bind to the bovine CD4 protein expressed in vitro. Indirect immunofluorescence assay showed that four monoclonal antibodies were able to specifically recognize the natural bovine CD4 protein. Flow cytometry assay showed that 3F9 was best to recognize bovine natural CD4 molecules. Conclusion Four monoclonal antibody strains with high specificity to natural bovine CD4 protein were successfully prepared, which lays the foundation for the subsequent studies on the function of bovine CD4 and diagnosis and treatment of bovine T-lymphocyte diseases.
Animals ; Antibodies, Monoclonal/isolation & purification* ; Cattle ; CD4 Antigens/genetics* ; Hybridomas/immunology* ; Antibody Specificity/immunology* ; Mice ; Mice, Inbred BALB C ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique, Indirect

OBJECTIVE: To observe the clinical effect of plasma exchange and tocilizumab in treatment of patients with severe coronavirus disease 2019 (COVID-19). METHODS: Six patients with severe COVID-19 admitted in First Affiliated Hospital of Bengbu Medical College from January 25 to February 25, 2020. Three patients were treated with plasma exchange and three patients were treated with tocilizumab. The effect on excessive inflammatory reaction of plasma exchange and tocilizumab was observed. RESULTS: The C-reactive protein (CRP) and IL-6 levels were significantly decreased and the lymphocyte and prothrombin time were improved in 3 patients after treatment with plasma exchange; while inflammation level was not significantly decreased, and lymphocyte and prothrombin time did not improve in 3 patients treated with tocilizumab. CONCLUSIONS For severe COVID-19 patients with strong inflammatory reaction, plasma exchange may be preferred.
Antibodies, Monoclonal, Humanized ; administration & dosage ; Betacoronavirus ; isolation & purification ; Coronavirus Infections ; blood ; immunology ; therapy ; Cytokine Release Syndrome ; therapy ; Humans ; Pandemics ; Plasma Exchange ; standards ; Pneumonia, Viral ; blood ; immunology ; therapy ; Prothrombin Time ; Treatment Outcome

By using an RAD peptide display system derived from the ATPase domain of recombinase RadA of Pyrococcus furiosus, an anti-hCG antibody-like molecule was prepared by grafting an hCG-binding peptide to the RAD scaffold. After linking to sfGFP gene, a gene of hCG peptide-grafted RAD was synthesized and cloned into a bacterial expression vector (pET30a-RAD/hCGBP-sfGFP). The vector was transformed into Escherichia coli, and expression of the fusion protein was induced. After isolation and purification of the fusion protein, its binding affinity and specificity to hCG were determined by using a process of immunoabsorption followed by GFP fluorescence measurement. A comparison of hCG-binding activity with a similarly grafted single-domain antibody based on a universal scaffold was performed. The measurement of hCG-binding affinity and specificity revealed that the grafted RAD has an optimally high binding affinity and specificity to hCG, which are better than the grafted single-domain antibody. Moreover, the affinity and specificity of grafted RAD molecule are comparable to those of a commercial monoclonal antibody. In addition, the hCG-binding peptide-grafted RAD molecule has a relatively high biochemical stability, making it a good substitute for antibody with potential application.
Antibodies, Monoclonal ; chemistry ; isolation & purification ; metabolism ; Antibody Specificity ; DNA-Binding Proteins ; genetics ; metabolism ; Escherichia coli ; genetics ; Escherichia coli Proteins ; metabolism ; Humans ; Peptides ; Recombinant Fusion Proteins ; genetics ; metabolism

Rice stripe virus (RSV) causes dramatic losses in rice production worldwide. In this study, two monoclonal antibodies (MAbs) 16E6 and 11C1 against RSV and a colloidal gold-based immunochromatographic strip were developed for specific, sensitive, and rapid detection of RSV in rice plant and planthopper samples. The MAb 16E6 was conjugated with colloidal gold and the MAb 11C1 was coated on the test line of the nitrocellulose membrane of the test strip. The specificity of the test strip was confirmed by a positive reaction to RSV-infected rice plants and small brown planthopper (SBPH), and negative reactions to five other rice viruses, healthy rice plants, four other vectors of five rice viruses, and non-viruliferous SBPH. Sensitivity analyses showed that the test strip could detect the virus in RSV-infected rice plant tissue crude extracts diluted to 1:20 480 (w/v, g/mL), and in individual viruliferous SBPH homogenate diluted to 1:2560 (individual SPBH/μL). The validity of the developed strip was further confirmed by tests using field-collected rice and SBPH samples. This newly developed test strip is a low-cost, fast, and easy-to-use tool for on-site detection of RSV infection during field epidemiological studies and paddy field surveys, and thus can benefit decision-making for RSV management in the field.
Antibodies, Monoclonal/chemistry* ; China ; Chromatography, Affinity/methods* ; Collodion/chemistry* ; Colloids/chemistry* ; Gold Colloid/chemistry* ; Materials Testing ; Membranes, Artificial ; Oryza/virology* ; Plant Diseases/virology* ; Reproducibility of Results ; Sensitivity and Specificity ; Species Specificity ; Tenuivirus/isolation & purification*

Therapeutic monoclonal antibodies become the major product class within the biopharmaceutical market. Protein A as the first capture step is still dominant in current platforms for purification of monoclonal antibodies. In this study, we developed a new antibody harvest process that incorporates acidic treatment of cell harvest, demonstrating high process yield, improved clearance of host cell associated contaminants, like non-histone host cell protein, histone, DNA and heteroaggregates. Host protein contamination was reduced about 10-fold compared to protein A loaded with harvest clarified by centrifugation and microfiltration. Turbidity increase of eluted IgG upon pH neutralization was nearly eliminated. Residual levels of impurities in the protein A eluate were achieved that potentially meet requirements of drug substance and thus alleviate the burden for further impurities removal in subsequent chromatography steps. The mechanism of host cell associated contaminants removal during acidic treatment was also explored. After a polishing step by Capto adhere, host cell protein was reduced to less than 5 ppm, DNA less than 1 ppb, histone to undetectable level, heteroaggregates less than 0.01% with total IgG recovery around 87%. This efficient process can be easily integrated into current IgG purification platforms, and may overcome downstream processing challenges.
Antibodies, Monoclonal ; isolation & purification ; Biotechnology ; Chromatography, Affinity ; DNA ; Histones ; Hydrogen-Ion Concentration ; Immunoglobulin G ; isolation & purification ; Staphylococcal Protein A ; chemistry

BACKGROUND/AIMS: The relationship between patient survival and biopsy-proven acute rejection (BPAR) in liver transplant recipients with hepatitis C remains unclear. The aims of this study were to compare the characteristics of patients with and without BPAR and to identify risk factors for BPAR. METHODS: We retrospectively reviewed the records of 169 HCV-RNA-positive patients who underwent LT at three centers. RESULTS: BPAR occurred in 39 (23.1%) of the HCV-RNA-positive recipients after LT. The 1-, 3-, and 5-year survival rates were 92.1%, 90.3%, and 88.5%, respectively, in patients without BPAR, and 75.7%, 63.4%, and 58.9% in patients with BPAR (P<0.001). Multivariate analyses showed that BPAR was associated with the non-use of basiliximab and tacrolimus and the use of cyclosporin in LT recipients with HCV RNA-positive. CONCLUSION: The results of the present study suggest that the immunosuppression status of HCV-RNA-positive LT recipients should be carefully determined in order to prevent BPAR and to improve patient survival.
Antibodies, Monoclonal/therapeutic use ; Biopsy ; Cyclosporine/therapeutic use ; Drug Therapy, Combination ; Genotype ; Graft Rejection/mortality/*prevention & control ; Hepacivirus/genetics/isolation & purification ; Hepatitis C/drug therapy/*virology ; Humans ; Immunosuppressive Agents/*therapeutic use ; *Liver Transplantation/adverse effects ; Polymerase Chain Reaction ; RNA, Viral/blood ; Recombinant Fusion Proteins/therapeutic use ; Recurrence ; Retrospective Studies ; Survival Rate ; Tacrolimus/therapeutic use

We established an ELISPOT for bovine interferon-gamma (BoIFN-γ), and applied it in the diagnosis of bovine tuberculosis (bTB). Monoclonal antibodies that can bind with native BoIFN-γ were screened as the coating antibody and detecting antibody. After optimization of detecting conditions including coating antibody concentration, cell number, and detecting antibody concentration, the ELISPOT assay was established. Peripheral mononuclear cells (PBMCs) isolated from 30 cows were co-cultured with PPD, and detected with the ELISPOT assay. The optimal conditions of ELISPOT assay were 2.5 μg/mL coating antibody 2G5, 2.5 x 10(5) cells/well, and 1 μg/mL detecting antibody Bio-5E11. In these 30 cows tested both with the ELISPOT assay and the BOVIGAM kit, 11 cows were proved to be positive in ELISOPT assay with the sensitivity of 78.6%, and 12 cows were proved to be negative in ELISOPT assay with the specificity of 75%. The ELISPOT assay for BoIFN-γ could be used to detect bTB efficiently and it might be an alternative method for the diagnosis of bTB.
Animals ; Antibodies, Monoclonal ; Cattle ; Enzyme-Linked Immunospot Assay ; veterinary ; Female ; Interferon-gamma ; isolation & purification ; Sensitivity and Specificity ; Tuberculosis, Bovine ; diagnosis

The aims of this study were to assess the risk of tuberculosis (TB) and the status of latent tuberculosis infection (LTBI) in Korean patients with inflammatory bowel disease (IBD) receiving tumor necrosis factor (TNF)-alpha blockers. We reviewed medical records of 525 Korean IBD patients (365 TNF-alpha blocker naive and 160 TNF-alpha blocker exposed) between January 2001 and December 2013. The crude incidence of TB was significantly higher in IBD patients receiving TNF-alpha blockers compared to TNF-alpha-blocker-naive patients (3.1% vs. 0.3%, P=0.011). The mean incidence of TB per 1,000 patient-years was 1.84 for the overall IBD population, 4.89 for TNF-alpha blocker users, and 0.45 for TNF-alpha-blocker-naive patients. The adjusted risk ratio of TB in IBD patients receiving TNF-alpha blocker was 11.7 (95% confidence interval, 1.36-101.3). Pulmonary TB was prevalent in patients treated with TNF-alpha blockers (80.0%, 4/5). LTBI was diagnosed in 17 (10.6%) patients, and none of the 17 LTBI patients experienced reactivation of TB during treatment with TNF-alpha blockers. Treatment with TNF-alpha blockers significantly increased the risk of TB in IBD patients in Korea. De novo pulmonary TB infection was more prevalent than reactivation of LTBI, suggesting an urgent need for specific recommendations regarding TB monitoring during TNF-alpha blocker therapy.
6-Mercaptopurine/adverse effects/analogs & derivatives/therapeutic use ; Adult ; Anti-Inflammatory Agents, Non-Steroidal/adverse effects/therapeutic use ; Antibodies, Monoclonal/adverse effects/therapeutic use ; Cohort Studies ; Colitis, Ulcerative/*drug therapy ; Crohn Disease/*drug therapy ; Female ; Humans ; Latent Tuberculosis/chemically induced/diagnosis/*epidemiology ; Male ; Mycobacterium tuberculosis/isolation & purification ; Republic of Korea ; Retrospective Studies ; Tuberculosis, Pulmonary/chemically induced/diagnosis/*epidemiology ; Tumor Necrosis Factor-alpha/*antagonists & inhibitors

The aims of this study were to assess the risk of tuberculosis (TB) and the status of latent tuberculosis infection (LTBI) in Korean patients with inflammatory bowel disease (IBD) receiving tumor necrosis factor (TNF)-alpha blockers. We reviewed medical records of 525 Korean IBD patients (365 TNF-alpha blocker naive and 160 TNF-alpha blocker exposed) between January 2001 and December 2013. The crude incidence of TB was significantly higher in IBD patients receiving TNF-alpha blockers compared to TNF-alpha-blocker-naive patients (3.1% vs. 0.3%, P=0.011). The mean incidence of TB per 1,000 patient-years was 1.84 for the overall IBD population, 4.89 for TNF-alpha blocker users, and 0.45 for TNF-alpha-blocker-naive patients. The adjusted risk ratio of TB in IBD patients receiving TNF-alpha blocker was 11.7 (95% confidence interval, 1.36-101.3). Pulmonary TB was prevalent in patients treated with TNF-alpha blockers (80.0%, 4/5). LTBI was diagnosed in 17 (10.6%) patients, and none of the 17 LTBI patients experienced reactivation of TB during treatment with TNF-alpha blockers. Treatment with TNF-alpha blockers significantly increased the risk of TB in IBD patients in Korea. De novo pulmonary TB infection was more prevalent than reactivation of LTBI, suggesting an urgent need for specific recommendations regarding TB monitoring during TNF-alpha blocker therapy.
6-Mercaptopurine/adverse effects/analogs & derivatives/therapeutic use ; Adult ; Anti-Inflammatory Agents, Non-Steroidal/adverse effects/therapeutic use ; Antibodies, Monoclonal/adverse effects/therapeutic use ; Cohort Studies ; Colitis, Ulcerative/*drug therapy ; Crohn Disease/*drug therapy ; Female ; Humans ; Latent Tuberculosis/chemically induced/diagnosis/*epidemiology ; Male ; Mycobacterium tuberculosis/isolation & purification ; Republic of Korea ; Retrospective Studies ; Tuberculosis, Pulmonary/chemically induced/diagnosis/*epidemiology ; Tumor Necrosis Factor-alpha/*antagonists & inhibitors

There is no consensus on whether it is safe to re-administer tumor necrosis factor-alpha (TNFalpha) inhibitors in patients with rheumatoid arthritis (RA) or ankylosing spondylitis (AS) flared after withdrawal of TNFalpha inhibitors due to active tuberculosis (TB). We evaluated the safety of restarting anti-TNFalpha therapy in patients with TNFalpha-associated TB. We used data of 1,012 patients with RA or AS treated with TNFalpha inhibitors at Seoul St. Mary's Hospital between January 2003 and July 2013 to identify patients who developed active TB. Demographic and clinical data including the results of tuberculin skin tests (TST) and interferon-gamma releasing assays (IGRA) were collected. Fifteen patients developed active TB. Five cases were occurred in RA and 10 cases in AS. Nine of 15 patients had a negative TST or IGRA and 6 TST-positive patients had received prophylaxis prior to initiating anti-TNFalpha therapy. All patients discontinued TNFalpha inhibitors with starting the treatment of TB. Eight patients were re-administered TNFalpha inhibitors due to disease flares and promptly improved without recurrence of TB. TNFalpha inhibitors could be safely resumed after starting anti-TB regimen in patients with RA or AS.
Adult ; Aged ; Anti-Inflammatory Agents, Non-Steroidal/adverse effects/therapeutic use ; Antibodies, Monoclonal/adverse effects/therapeutic use ; Antibodies, Monoclonal, Humanized/adverse effects/therapeutic use ; Antirheumatic Agents/adverse effects/therapeutic use ; Arthritis, Rheumatoid/*drug therapy ; Enzyme Inhibitors/adverse effects/therapeutic use ; Female ; Humans ; Hydroxychloroquine/adverse effects/therapeutic use ; Immunoglobulin G/adverse effects/therapeutic use ; Immunosuppressive Agents/adverse effects/*therapeutic use ; Interferon-gamma Release Tests ; Male ; Methotrexate/adverse effects/therapeutic use ; Middle Aged ; Mycobacterium tuberculosis/isolation & purification ; Receptors, Tumor Necrosis Factor/therapeutic use ; Retrospective Studies ; Spondylitis, Ankylosing/*drug therapy ; Tuberculin Test ; Tuberculosis/*chemically induced/microbiology ; Tumor Necrosis Factor-alpha/*antagonists & inhibitors