Generation and characterization of mouse monoclonal antibodies against NS4B protein of dengue virus

- Two mouse monoclonal antibodies (10-3-7 and 44-4-7) against DENV NS4B were generated and characterized.
- MAb 10-3-7 is specific against DENV-2.
- The epitope of mAb 10-3-7 is mapped to the N-terminus of NS4B.
- MAb 44-4-7 displays cross-reactivity among four serotypes of DENV and WNV.
- The epitope of mAb 44-4-7 is mapped to the cytosolic-oriented loop of NS4B.

Dengue virus (DENV) non-structural protein 4B (NS4B) has been demonstrated to be an attractive antiviral target. Due to its nature as an integral membrane protein, NS4B remains poorly characterized. In this study, we generated and characterized two monoclonal antibodies (mAb) that selectively bind to DENV NS4B protein. One mAb, 10-3-7, is specific for DENV-2 NS4B, and its epitope was mapped to residues 5-15 of NS4B. The other mAb, 44-4-7, cross-reacts with all the four serotypes of DENV NS4B, and its epitope was mapped to residues 141-147 of NS4B. Using the mAbs, we probed the intracellular orientation of the epitopes of NS4B by an epitope accessibility assay. The results showed that the N-terminus of NS4B is located in the ER lumen, whereas amino acids 130-148 of NS4B are located in the cytosol. The study demonstrates that the two anti-NS4B mAbs will be useful for future structural and functional analyses of DENV NS4B.