The voltage-gated Na channel subtype Nav1.7 is important for pain and itch in rodents and humans. We previously showed that a Nav1.7-targeting monoclonal antibody (SVmab) reduces Na currents and pain and itch responses in mice. Here, we investigated whether recombinant SVmab (rSVmab) binds to and blocks Nav1.7 similar to SVmab. ELISA tests revealed that SVmab was capable of binding to Nav1.7-expressing HEK293 cells, mouse DRG neurons, human nerve tissue, and the voltage-sensor domain II of Nav1.7. In contrast, rSVmab showed no or weak binding to Nav1.7 in these tests. Patch-clamp recordings showed that SVmab, but not rSVmab, markedly inhibited Na currents in Nav1.7-expressing HEK293 cells. Notably, electrical field stimulation increased the blocking activity of SVmab and rSVmab in Nav1.7-expressing HEK293 cells. SVmab was more effective than rSVmab in inhibiting paclitaxel-induced mechanical allodynia. SVmab also bound to human DRG neurons and inhibited their Na currents. Finally, potential reasons for the differential efficacy of SVmab and rSVmab and future directions are discussed.
Animals ; Antibodies, Monoclonal ; therapeutic use ; Biotin ; metabolism ; Cells, Cultured ; Disease Models, Animal ; Female ; Ganglia, Spinal ; cytology ; HEK293 Cells ; Humans ; Hybridomas ; chemistry ; Hyperalgesia ; drug therapy ; Male ; Mice ; Mice, Inbred C57BL ; NAV1.5 Voltage-Gated Sodium Channel ; metabolism ; NAV1.7 Voltage-Gated Sodium Channel ; chemistry ; immunology ; metabolism ; Neuralgia ; drug therapy ; metabolism ; Protein Binding ; drug effects ; Recombinant Proteins ; biosynthesis ; therapeutic use ; Sensory Receptor Cells ; drug effects ; physiology

In order to develop monoclonal antibodies (McAbs) against the gp90 protein of reticuloendotheliosis virus (REV), the His-tagged gp90 protein of REV was used to immunize BALB/c mice. Hybridomas were generated by fusing mouse myeloma cells SP2/0 with the splenocytes from the immunized mice. After screening and 3 rounds of cloning process, 3 hybridomas (3G5-B8, 3G5-A10 and 1G12) that stably secreted McAbs against the REV-gp90 were obtained. The isotypes of the McAbs were determined to be IgG1, IgG1 and IgG2b. The McAbs specifically bound to gp90 in REV-infected DF-1 cells, as demonstrated by Western blotting and indirect immunofluorescence assay. The recognition regions on gp90 that were recognized by 3G5-B8/3G5-A10 and 1G12 were located between amino acids 200 to 245 and 230 to 235, respectively, as demonstrated by Western blotting analysis. These McAbs will be useful in the diagnosis and pathogenesis study of REV.
Animals ; Antibodies, Monoclonal ; biosynthesis ; Antibody Specificity ; Blotting, Western ; Epitope Mapping ; Hybridomas ; Immunoglobulin G ; biosynthesis ; Mice ; Mice, Inbred BALB C ; Reticuloendotheliosis virus ; immunology ; Viral Envelope Proteins ; immunology

OBJECTIVETo prepare rabbit monoclonal antibody (RabMab) against guanosine 3', 5'-cyclic monophosphate (cGMP) and to develop a competitive ELISA for the detection of cGMP.

METHODSNew Zealand white rabbits were immunized with synthesized cGMP-keyhole limpet hemoeyanin (cGMP-KLH) to prepared a RabMAb with monoclonal antibody technique of Epitomics. A competitive ELISA kit was produced with cGMP RabMAb. The specificity, the precision and the recoveries of the method were determined.

RESULTSThe RabMAb with high sensitivity towards cGMP were prepared with an antibody timer of 3.1 ng/mL and 50% inhibitive concentration (IC50) of 12.57 ng/mL. The cGMP RabMAb had 33% cross-reactivity to inosine 3', 5'-cyclic monophosphate (cIMP) and little or no cross-reactivity to other compounds. A competitive ELISA was developed for detection of cGMP. The range of detection was 0~120 ng/mL with a minimal limit of 1.95 ng/mL. The recovery of assay was 89%~103%. The inter-assay and intra-assay coefficient variations were below 11.68% and 13.85%, respectively.

CONCLUSIONThe RabMab against cGMP with high affinity and high specificity has been generated successfully, and a competitive ELISA for detection of cGMP has been developed with the prepared cGMP RabMAb.

Animals ; Antibodies, Monoclonal ; biosynthesis ; Antibody Specificity ; Cross Reactions ; Cyclic GMP ; immunology ; Enzyme-Linked Immunosorbent Assay ; Rabbits

Infectious bursal disease virus (IBDV) VP4 plays an important role in immunosuppression of host. In order to develop monoclonal antibodies (McAbs) against VP4, we vaccinated BALB/c mice with His-VP4, screened and subcloned positive clones. We established 4 hybridoma cell lines that stably secreted McAbs against VP4 and named these cell lines 3B3, 3H11, 4C8 and 4G6, respectively. We tested the dissociation constant (Kd) of these McAbs, and found that their K(d)s were 4.61 x 10(-11), 1.71 x 10(-10), 4.26 x 10(-11), 5.02 x 10(-11), respectively. The isotypes of these McAbs were determined to be IgG1, IgG1, IgG2b and IgG1. These McAbs specifically bound to VP4 in IBDV infected DF-1 cells as demonstrated by Western blotting analysis and fluorescence antibody assay. These McAbs would help to detect IBDV infection and to analyze the biological activities of IBDV VP4.
Animals ; Antibodies, Monoclonal ; biosynthesis ; Blotting, Western ; Cell Line ; Fluorescent Antibody Technique ; Hybridomas ; Infectious bursal disease virus ; Mice ; Mice, Inbred BALB C ; Viral Structural Proteins ; immunology

A truncated mutant of the Open Reading Frame 2 (ORF2, aa384-606) was amplified from cDNA of genotype IV hepatitis E virus (HEV) by polymerase chain reaction (PCR), subcloned to expression plasmid pTO-T7, and expressed in Escherichia coli. SDS-PAGE and Western blotting were used to detect and identify the recombinant protein, namely rP24. After washing of inclusion bodies, dissolving in denaturing agents, refoldeding by dialysis, ion exchange chromatography and gel chromatography, dynamic light scatter was used to study the hydrated radius of rP24. Western blotting was applied to detect the immunoreactivity of rP24, and mouse immunity test and indirect enzyme linked immunosorbent assay (ELISA) were applied to evaluate the immunogenicity and the detection rate of HEV positive and negative serum. SDS-PAGE and Western blotting show that rP24 was highly expressed in the form of inclusion bodies after induction, and had strong immunoreactivity to monoclonal antibody (McAb) 15B2. After a multi-step purification of rP24, Western blotting indicated that the purified rP24 also had strong immunoreactivity to neutralizing McAb 8C11 and HEV positive serum, suggesting that rP24 simulated the nature structure of HEV capsid protein. Dynamic light scatter demonstrated that the average hydration radius of purified rP24 was 7.48 nm. The mouse immunity test showed that the purified rP24 also had good immunogenicity, and the period of serum antibodies converted from negative to positive was very short, but the antibodies maintained more than 20 weeks. Indirect ELISA tests showed that the detection rate of was the same as anti-HEV-IgG diagnostic kit (Wan Tai corporation). Taken together, the rP24 simulated the neutralizing epitopes of natural HEV, and had strong immunoreactivity and immunogenicity. It provided a basis for the further investigation of the difference of infection mechanism between genotype I and genotype IV HEV.
Animals ; Antibodies, Monoclonal ; Antibodies, Neutralizing ; Blotting, Western ; Capsid Proteins ; biosynthesis ; Electrophoresis, Polyacrylamide Gel ; Enzyme-Linked Immunosorbent Assay ; Epitopes ; Genotype ; Hepatitis E virus ; Mice ; Mutant Proteins ; biosynthesis ; Open Reading Frames ; Recombinant Proteins ; biosynthesis

Antibodies, Monoclonal ; chemistry ; immunology ; Antigens, Viral ; chemistry ; genetics ; immunology ; Binding Sites ; Capsid Proteins ; chemistry ; genetics ; immunology ; Epitopes ; chemistry ; genetics ; immunology ; Escherichia coli ; genetics ; metabolism ; Gene Expression ; Hepatitis E ; immunology ; prevention & control ; virology ; Hepatitis E virus ; chemistry ; immunology ; Humans ; Molecular Docking Simulation ; Mutagenesis, Site-Directed ; Peptide Mapping ; Protein Binding ; Recombinant Proteins ; chemistry ; genetics ; immunology ; Viral Hepatitis Vaccines ; administration & dosage ; biosynthesis

Adult ; Antibodies, Monoclonal ; pharmacology ; Bronchoalveolar Lavage Fluid ; cytology ; Cells, Cultured ; Cytokines ; biosynthesis ; blood ; secretion ; Fas Ligand Protein ; antagonists & inhibitors ; metabolism ; Humans ; Macrophages, Alveolar ; immunology ; metabolism ; Middle Aged ; Occupational Exposure ; analysis ; Signal Transduction ; Silicon Dioxide ; adverse effects ; Silicosis ; blood ; immunology ; fas Receptor ; antagonists & inhibitors ; metabolism

This research was to construct the lentiviral expression vector for anti- p185(erbB2) mouse/human chimeric antibody and to determine the expression of the chimeric antibody gene in 293T cells transfected with this vector. The genes (vL and vH) coding light and heavy chain of variable regions of anti-p185(erbB2) mAb and the constant regions of human IgG1 (kappa and gamma1) were cloned with PCR method. The target genes were assembled by three-primers PCR method to obtain the chimeric light chain (L) and the chimeric heavy chain (H). Both chains inserted into the down stream and upper stream of IRES gene of the plasmid pVAX1/IRES respectively. We digested the plasmid pVAX1/ H-IRES-L with endoenzyme and subcloned H-IRES-L into the lentiviral vector pWPI. The enzyme digestion and sequence analysis showed that the lentiviral expression vector pWPI/H-IRES-L was constructed correctly. Then, it was transfected into 293T cells and after 48h, GFP protein expression in 293T cells were detected by fluorescent microscope and the chimeric antibody expression was detected by RT-PCR and direct ELISA. The results showed that after 293T cells were transfected with recombination plasmid, both light and heavy chains of the chimeric antibody genes could express together. The chimeric antibody expressed could bind to p185(erbB2) specifically. This research may lay a sound foundation for further study of anti-p185(erbB2) engineered antibody.
Animals ; Antibodies, Monoclonal ; biosynthesis ; genetics ; Cell Line ; Chimera ; Cloning, Molecular ; Humans ; Lentivirus ; genetics ; metabolism ; Mice ; Receptor, ErbB-2 ; biosynthesis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Transfection

OBJECTIVETo prepare a monoclonal antibody (mAb) against extracellular domain of B7-H4 and to investigate the expression of B7-H4 in pancreatic cancer tissue with the prepared mAb.

METHODSBalb/c mice were immunized with 3T3-B7-H4 cells and the splenic cells of the immunized mice were fused with Sp2/0 myeloma cells by conventional hybridoma techniques. An indirect ELISA method using 3T3-B7-H4 lysate as antigen was established to screen antibody-producing hybridoma cell lines. Western blott, immunoprecipitation (IP), and immunohistochemistry (IHC) were applied to characterize the mAb. Immunohistochemical staining was used to detect the expression of B7-H4 in human pancreatic cancer tissue. The correlation of B3-H4 expressions and pathological features of pancreatic cancer was analyzed.

RESULTSA hybridoma cell line secreting mAb against B7-H4 was obtained. The subclass of this mAb was IgM, and the light chain was Kappa. Western blot and IP showed that the mAb specifically recognized B7-H4. IHC staining revealed that the mAb stained in a predominantly diffuse plasmalemmal or cytoplasmic pattern when applied to certain tumor tissues. The B7-H4 was diffusely expressed in the cytoplasma and/or membrane of pancreatic cancer tissue, which was much higher than that expressed in normal pancreatic tissue (4.00 ± 1.44 compared with 1.12 ± 0.78, P ± 0.01). The expression of B7-H4 was higher in pancreatic cancer tissues with higher pathological grade or with lymph node metastasis as compared with that in pancreatic cancer tissues with lower grade or with no lymph mode metastasis (6.10 ± 0.72 compared with 3.55 ± 1.12,P<0.01: 6.14 ± 0.66 compared with 3.70 ± 1.25,P<0.01). The expression level of B7-H4 was not related to patients'age and gender.

CONCLUSIONMonoclonal antibody against B7-H4 with high activity and specificity has been prepared successfully. The expression of B7-H4 in pancreatic cancer tissue is up-regulated,which is closely related to the tumor grade and lymph node metastasis in pancreatic cancer.

3T3 Cells ; Animals ; Antibodies, Monoclonal ; biosynthesis ; Cell Line, Tumor ; Humans ; Immunohistochemistry ; Lymphatic Metastasis ; Mice ; Mice, Inbred BALB C ; Neoplasm Grading ; Pancreatic Neoplasms ; metabolism ; pathology ; V-Set Domain-Containing T-Cell Activation Inhibitor 1 ; metabolism

With the advantage of clear target and little side effect, antibody drug has attracted widely attention of worldwide pharmaceutical companies. However, large scale mammalian cell culture and antibody quality analysis are the bottlenecks of antibody drug industrialization in China. Especially due to the significant effect of cell culture conditions on antibody heterogeneity. Therefore, it is extremely urgent to optimize cell culture conditions to favor the demands of antibody drug development. This review summarized the most recent advances in the effect of cell culture conditions on antibody quality, followed by addressing the key issues that might be strategically important for domestic antibody drug development.
Animals ; Antibodies, Monoclonal ; biosynthesis ; isolation & purification ; Antibody Formation ; Cell Culture Techniques ; methods ; trends ; Genetic Heterogeneity ; Protein Stability ; Quality Control