Pigeon Newcastle disease (PND), caused by pigeon paramyxovirus type 1 (PPMV-1), is an acute, highly contagious disease that induces neurological symptoms and gastrointestinal disorders in pigeons, posing substantial economic risks to the global pigeon industry. The hemagglutinin-neuraminidase (HN) protein of PPMV-1 is a key surface glycoprotein mediating viral adsorption, invasion, and egress, and serves as a critical target for vaccine development and diagnostic reagent design. In this study, we aimed to generate a specific monoclonal antibody (mAb) against the HN protein of PPMV-1 and identify its recognized epitope. We codon-optimized the conserved 198–390 amino acid (aa) region of the HN protein from PPMV-1 strain, followed by prokaryotic expression and purification to serve as the immunogen. Through cell fusion monoclonal antibody screening, we successfully established a hybridoma cell line that secretes mAb 4H3. Western blot and immunofluorescence assay (IFA) confirmed that mAb 4H3 specifically reacts with PPMV-1 strains but exhibits no cross-reactivity with the commonly used NDV vaccine strain Lasota. Epitope mapping with a panel of truncated HN protein fragments identified the minimal B-cell epitope recognized by mAb 4H3 as 310 DRVWF 314 . Sequence homology analysis showed this epitope is highly conserved across PPMV-1 strains. Collectively, our results offer a valuable tool for developing PPMV-1-specific diagnostic assays, as well as for investigations into HN protein function and the development of epitope-based vaccines against PND.
Wang et al. (Fri,) studied this question.