An engineered canine-mouse chimeric neutralizing antibody provides therapeutic effects against canine parvovirus...

Canine parvovirus (CPV) is a highly contagious and severe infectious disease that can lead to hemorrhagic enteritis and even acute death in dogs. Despite mouse monoclonal antibodies (mAbs) have been employed in clinical treatment, their application in non-murine species is restricted due to immune rejection. In this study, we screened a mouse mAb (5E7) with high neutralizing activity against CPV using hybridoma technology. Subsequently, the variable regions of the heavy (VH) and light (VL) chains of 5E7 were amplified by PCR and fused with the constant regions of canine IgG antibody to produce canine-mouse chimeric antibody (CM-5E7). The chimeric antibody was successfully expressed in HEK293 cells and exhibited high neutralizing activity against multiple CPV subtypes in vitro. Furthermore, CM-5E7 exhibited effective therapeutic potential in dogs subjected to lethal dose CPV-2c challenge in vivo. Overall, CM-5E7 demonstrated high neutralizing activity against CPV and showed significant efficacy in treating CPV-2c infections, positioning it as a promising candidate therapeutic antibody for the treatment of CPV infection.