The MRC OX-62 Antigen: A Useful Marker in the Purification of Rat Veiled Cells with the Biochemical Properties of an Integrin By M. Brenan and M. Puklavec

A mouse immunoglobulin G1 monoclonal antibody (mAb), MRC OX-62 (OX-62), was raised against density gradient-enriched rat veiled (dendritic) cells obtained from lymph. In suspensions of lymphoid cells, the OX-62 mAb only labeled cells with the characteristics of veiled cells. The OX-62 mAb was used with a magnetic cell sorter to enrich or deplete veiled cells, and the enriched veiled cells were potent stimulators in the primary allogeneic mixed leukocyte reaction. Immunohistochemical staining of tissue sections showed that the OX-62 mAb did not label all classical dendritic cells and was not restricted to this cell type. In lymphoid tissues, the labeling correlated with dendritic cells, but in skin, major histocompatibility complex class II + cells were OX-62-, while another CD3 + cell with dendritic morphology was strongly OX-62 + . It seems that the OX-62 mAb may be restricted to dendritic cells and probably to T/$ T cells. The OX-62 mAb will be of use in delineating minor subsets of cells with dendritic morphdogy in various tissues. Sodium dodecyl sulfate-polyacrylamide gel dectrophoresis analysis of veiled ceil-enriched populations immunoprecipitated with the OX-62 mAb gave bands with the biochemical characteristics of an integrin. The OX-62 mAb recognized the c~-like subunit.