Production of a monoclonal antibody (2B44) reactive on a shared epitope on dendritic reticulum cells, smooth muscle cells of vessels and Reed-Sternberg cells.

Lymph node cells from a patient with Hodgkin's disease (HD) were cultured without Epstein-Barr virus (EBV) or leukine adjuvant. A cell line (719-AB) emerged from the culture after four weeks. The cell line express CD20 (79%), CD 21 (30%), CD30 (63%), CD 35 (61%) antigens and weakly CD25 (19%). using Southern Blot technique, the existence of specific EBV DNA and polyclonal immunoglobulin genes rearrangement were observed in the cell line. In order to obtain a monoclonal antibodies (MoAb), mice Balb/C were immunized with this cell line. The splenic cells suspension of immunized animals were fused with the mouse myeloma NS1. Antibody IgM kappa from secreting clones 2B44 was studied using both indirect immunofluorescence with labeled anti-mouse immunoglobulin and immunohistochemistry based on alkaline phosphatase/antiphosphatase complex (APAAP) and ModAMeX technique on a panel of normal or pathological cells. Normal peripheral lymphocytes, monocytes, polymorphonuclear cells, and erythrocytes, did not react. The MoAb 2B44 recognized the dendritic reticulum cells and the smooth muscle cells of vessels on frozen section and paraffin section from HD or reactive lymph nodes. On specially processed paraffin sections (ModAMeX) Reed-Sternberg cells (RSC) were reactive with 2B44 MoAb (in 2 cases out of 5 tested). The molecular weight of the antigen recognized by 2B44 MoAb is of 37 kd. The description of a new epitope shared by different histological components might be of interest for defining a new cluster and better understanding the nature of RSC.