A novel monoclonal antibody (FUN‐1) identifies an activation antigen in cells of the B‐cell lineage and Reed—Sternberg cells

Abstract

The characterization of a new monoclonal antibody (MoAb) recognizing a human B‐cell activation antigen, designated FUN‐1, is described in this paper. Immunoprecipitation revealed that FUN‐1 recognizes an antigen with a molecular weight (MW) of 75 kD. FUN‐1 reacts with pokeweed mitogen‐activated B lymphocytes and monocytes of peripheral blood, but not with unstimulated lymphocytes or granulocytes. It also reacts with large lymphoid cells in germinal centres, Epstein–Barr virus‐transformed B cell lines, large B‐cell lymphomas, Ki‐1‐positive anaplastic largecell lymphomas, and Reed–Sternberg cells of Hodgkin's disease, but not with Concanavalin A‐activated T cells, acute lymphoblastic leukaemias, T‐cell lymphomas, or low‐grade B‐cell leukaemias. These findings indicate that FUN‐1 recognizes a previously unreported B‐cell activation antigen. This MoAb appears to be useful for the study of maturation and differentiation in the B‐cell lineage as well as for the immunohistochemical diagnosis of B‐cell lymphomas and Hodgkin's disease.