Evidence for Multiple Applications of Monoclonal Antibody 5G10

MAb Targeting a Link Between ExoN and MTase of TGEV NSP14

Porcine transmissible gastroenteritis virus (TGEV) infection results in severe gastrointestinal disease manifesting vomiting, diarrhea in neonatal porcine, with extremely high mortality. Monoclonal antibody (MAb) specific to TGEV nonstructural protein (NSP)14 that contains two functional domains, exonuclease (ExoN) and methyltransferase (MTase) domains, may help elucidate the role of NSP14 in the viral life-cycle. In this study, we developed a murine MAb, designated 12F1, against TGEV NSP14 using traditional cell-fusion technique. It was shown the MAb can exclusively bind to viral NSP14, as evidenced by the results of indirect fluorescent assay and western blotting. Intriguingly, epitope screening assay shown that 12F1 targets a hinge region connecting ExoN and N7-MTase of NSP14.

A Monoclonal Antibody Targeting C-Terminal Domain of Transmissible Gastroenteritis Virus Spike Protein

The structure and function of the C-terminus domain (CTD) of porcine transmissible gastroenteritis virus (TGEV) spike protein remain largely unknown, thereby a specific monoclonal antibody (MAb) allows us to fully understand this domain. In this study, we developed a murine MAb against CTD of TGEV spike protein, as evidenced by the results of indirect fluorescent assay, Western blotting, and fluorescence-activated cell sorter. Further study showed that the MAb is able to exclusively recognize a 12-residue peptide (FKNVSDGVIYSV) derived from CTD of TGEV spike protein. This MAb can be used to elucidate the potential function of CTD of TGEV spike in virus attachment and entry, and warrants further intensive investigation.

Monoclonal Antibody That Inhibits Cleavage Activity of Japanese Encephalitis Virus NS3

Flavivirus protease has been deemed a potential target for drug and therapeutics development due to its crucial role in viral replication. In this study we prepared a monoclonal antibody (mAb) against nonstructural protein 3 (NS3) protease portion of Japanese encephalitis virus (JEV), and evaluated its inhibitory effect for NS3 protease activity. First, a JEV NS3 protease-specific mAb (designated 2C2) was generated by the traditional cell fusion technique. Second, the binding specificity of 2C2 for NS3 protease was determined by indirect fluorescent assay and Western blotting. Finally, inhibitory effect of 2C2 for NS3 protease cleaving human stimulator of interferon gene was evaluated. Therefore, mAb 2C2 provides a potential diagnostic tool for differential diagnosis for patients who have been vaccinated with inactivated vaccine or naturally infected, and might be genetically reconstructed and optimized for new therapeutics development.

Opportunities and challenges of the tag-assisted protein purification techniques: Applications in the pharmaceutical industry

Tag-assisted protein purification is a method of choice for both academic researches and large-scale industrial demands. Application of the purification tags in the protein production process can help to save time and cost, but the design and application of tagged fusion proteins are challenging. An appropriate tagging strategy must provide sufficient expression yield and high purity for the final protein products while preserving their native structure and function. Thanks to the recent advances in the bioinformatics and emergence of high-throughput techniques (e.g. SEREX), many new tags are introduced to the market. A variety of interfering and non-interfering tags have currently broadened their application scope beyond the traditional use as a simple purification tool. They can take part in many biochemical and analytical features and act as solubility and protein expression enhancers, probe tracker for online visualization, detectors of post-translational modifications, and carrier-driven tags. Given the variability and growing number of the purification tags, here we reviewed the protein- and peptide-structured purification tags used in the affinity, ion-exchange, reverse phase, and immobilized metal ion affinity chromatographies. We highlighted the demand for purification tags in the pharmaceutical industry and discussed the impact of self-cleavable tags, aggregating tags, and nanotechnology on both the column-based and column-free purification techniques.

Monoclonal Antibody Targeting a Conserved N-Terminal Epitope on 2Apro of Enteroviruses

Several members of enteroviruses (EVs) that belong to the EVs A and B species cause hand, foot, and mouth disease (HFMD) in infants and young children. The virus-specific protease 2A^pro is conserved in all the EV species, thus developing a monoclonal antibody (mAb) against 2A^pro may facilitate the identification from the HFMD-associated pathogens. In this study, we achieved a murine mAb, named 5A3, specifically toward EVA71 2A^pro by using the traditional hybridoma technique. The mAb 5A3 recognizes 2A^pro of both EVs A and B species, which was demonstrated by indirect fluorescent assay and Western blotting. Furthermore, a conserved N-terminal epitope on 2A^pro recognized by mAb 5A3 was defined by using an overlapping peptide-based enzyme-linked immunosorbent assay (ELISA). Therefore, the unique mAb targeting conserved EVs 2A^pro can be used as an important tool during both identifying the causative agent of HFMD and elucidating the pathological mechanism of HFMD.

Dual monoclonal antibody-based sandwich ELISA for detection of in vitro packaged Ebola virus

Background

Rapid transmission and high mortality of Ebola virus disease (EVD) highlight a urgent need of large scale, convenient and effective measure for Ebola virus screening. Application of monoclonal antibodies (mAbs) are crucial for establishment of an enzyme-linked immunosorbent assay (ELISA) with high sensitivity and specificity.

Methods

The traditional cell fusion technique was used to generate a panel of hybridomas. Two mAbs were characterized by SDS-PAGE, Western blot, Indirect immunofluorescence assay (IFA). A sandwich ELISA was established using the two mAbs. The detection capability of the ELISA was evaluated.

Results

In the current study, we produced two murine-derived mAbs (designated as 6E3 and 3F21) towards Zaire Ebola virus glycoprotein (GP), the major viral transmembrane spike protein associated with viral attachment. It was shown that 6E3 and 3F21 recognized GP1 and GP2 subunits of the GP respectively. Furthermore, 6E3 and 3F21 bound to corresponding epitopes on GP without reciprocal topographical interpretation. Subsequently, a sandwich ELISA based on the two mAbs were established and evaluated. The detection limit was 3.6 ng/ml, with a linear range of 3.6–100 ng/ml. More importantly, Ebola virus like particles (eVLPs) were able to be detected by this established virus detection measure.

Conclusions

We produced and characterized two murine-derived mAbs (designated as 6E3 and 3F21) towards Zaire Ebola virus glycoprotein (GP), and established a sandwich ELISA based on the mAbs. It was suggested that the sandwich ELISA provided an alternative method for specific and sensitive detection of Ebola virus in the field setting.