Preparation and characterization of monoclonal antibodies against bovine myeloperoxidase

We established eight cloned B-cell hybridomas producing monoclonal antibodies (Mo abs) against bovine myeloperoxidase (MPO). These anti-MPO (AM) Mo abs, designated AM1-AM8, all reacted similarly to three chromatographic forms of MPO, isolated from a single donor, in an enzyme linked immunosorbent assay. According to immunoblot analysis and ELISA the AM Mo abs are specific to bovine MPO and show no cross reactivity with other neutrophil granule proteins such as lactoferrin, lactoperoxidase and serum albumin. In immunoblot analyses IgG1 class AM1, AM2, AM3 and AM4 Mo abs immunostained the heavy subunit of the MPO (57 kDa). Additionally, the AM Mo abs seem to bind either the reactive site or epitopes on bovine MPO that affect the peroxidase activity of this enzyme. AM Mo abs reacted specifically with neutrophils but did not react with lymphocytes or epithelial cells. The present study shows that these AM Mo abs could be used for developing immunoassays to measure bovine MPO from biological fluids and for localizing neutrophils at sites of infections. They could also be useful in studies assessing the involvement of MPO in inflammatory processes in bovine species.