Preparation and epitope identification of duck myxovirus resistance protein monoclonal antibody 4B6 and its expression in duck embryonic tissue.

BACKGROUND: Myxovirus resistance (Mx) is a potent antiviral effector induced by interferons, playing a key role in restricting diverse viral infections. However, the specific functions of duck Mx remain poorly understood due to the lack of specific detection reagents. METHODS: In this study, we cloned the Mx gene from ShaoXing duck and expressed and purified its truncated fragment (Mx-a) in prokaryotic cells. Using this purified recombinant Mx-a protein as an immunogen, we generated a monoclonal antibody (4B6) that specifically recognizes native duck Mx. RESULTS: The antibody, an IgG1 subtype, exhibited high titer and excellent specificity. Further investigation confirmed that mAb 4B6 specifically detects endogenous Mx in duck embryonic tissues by Western blot and recognizes Mx expressed in eukaryotic cells by immunofluorescence. Through fine epitope mapping, the linear epitope recognized by mAb 4B6 was precisely defined as the amino acid sequence "IYFPVPEQ" (residues 67-74), which is highly conserved across different duck species. CONCLUSION: The specific monoclonal antibody 4B6 provides an essential tool for further studies on the biological functions, antiviral mechanisms, and innate immune role of duck Mx.