6.18 Analysis of the monoclonal antibodies comprising WC6

The WC6 antibovine monoclonal antibodies (mAbs) CC98, IL-A114 and IL-A53 were investigated for reactivity in sheep by (fluorescence activated cell sorting) FACS analysis, immunoprecipitation and immunohistology. The mAbs behave identically by all criteria although IL-A114 reacts more weakly than the other mAbs. This probably reflects limited cross-species reactivity. The mAbs stain <30% of lymphocytes from blood, efferent and afferent lymph and the majority of afferent lymph dendritic cells. They also weakly stain granulocytes. They precipitate molecules of apparent molecular weight 220 kD and 180–190 kD. Sequential immunoprecipitation shows that CC98 antigen is not related to CD45. Immunohistology indicates staining of B cell areas and macrophages in Peyer's patch and lamina propria. The data show that these monoclonal antibodies react with a molecule distinct from OvCD45R.