Production and characterization of monoclonal antibodies reactive with thechicken interleukin-15 receptor alpha chain

We recently cloned the genes encoding chicken IL-15 and IL-15 receptor (R) or. proteins. In this study, 12 monoclonal antibodies (mAbs) against recomb inant chicken IL-15R alpha were produced and characterized. By enzyme-linke d immunosorbent assay (ELISA), all mAbs showed binding specificity for IL-1 5R alpha, but not IL-2 or interferon-gamma, and identified a 25.0 kDa prote in by immunoblot analysis. Flow cytometric analysis revealed negligible exp ression of IL-15Ra on nonactivated lymphocytes from the spleen, thymus or b ursa, low but detectable expression on macrophages and high expression on c oncanavalin A-activated spleen lymphoblasts. Established chicken T cell (RP 13) and macrophage (HD11) cell lines expressed substantially higher levels of IL-15R alpha compared with a B cell line Two mAbs inhibited IL-15 depend ent proliferation of T cells suggesting that the tertiary structure of the protein domain of native IL-15R alpha that binds to IL-15 is preserved in t he recombinant receptor molecule. These mAbs will be useful reagents for fu rther in vitro and in vivo studies of the biological functions of chicken I L-15 and its receptor. Published by Elsevier Science B.V.