Development and characterization of a novel mouse anti-canine oncostatin M receptor beta monoclonal antibody

Oncostatin M receptor beta (OSMRβ) mediates signaling of Oncostatin M (OSM) and interleukine-31 (IL-31), two key cytokines involved in many important biological processes including inflammation and cancer progression. More importantly, OSMRβ might be a potential biomarker and therapeutic target for some diseases, such as inflammatory bowel disease, pruritus and ovarian cancer. In this study, soluble recombinant canine OSMRβ (cOSMRβ) was experimentally expressed as a native antigen to develop an effective cOSMRβ-specific monoclonal antibody (mAb), 2O2, using hybridoma technology. It was demonstrated that 2O2 is able to detect OSMRβ expressed on cell surface using immunofluorescence assay (IFA) and flow cytometry (FACS). This mAb exhibits very high binding affinity to cOSMRβ with the KD and half-maximal effective concentration (EC50) values of 2.49 nM and 96.96 ng/ml, respectively. Meanwhile, it didn't show any cross-relativities with feline OSMRβ (fOSMRβ) and human OSMRβ (hOSMRβ). Moreover, we determined the binding epitope of 2O2, which localizes in the domain VI (DVI, amino acids 623-734) of cOSMRβ. In conclusion, this novel mAb, 2O2, can be used in immunoassays, including IFA, FACS and enzyme-linked immunosorbent assay (ELISA) to facilitate studies in dogs.