FOLLICULAR DENDRITIC CELLS IN NON-HODGKIN-LYMPHOMA EXPRESS ADHESION MOLECULES COMPLEMENTARY TO LIGANDS ON NEOPLASTIC B-CELLS

In non-Hodgkin-lymphoma (NHL) with nodular growth patterns, follicular dendritic cells (FDC) form a spherical network which contains neoplastic B-cells. in order to dissect the basis of this close FDC/B cell association, the antigenic profile of adhesion molecules expressed by individual FDC and NHL-B-lymphocytes was evaluated. FDC isolated from NHL were found to express C3bi receptors (CD11b), the very late antigen (VLA) alpha-5- and alpha-6-chain (CD49e, CD49f), and the intercellular adhesion molecule-1 (ICAM-1; CD54). Only a percentage of the FDC population was positive for the VLA beta-1- and alpha-3-chain (CD29, CD49c), the vitronectin receptor (CD51) and the vascular cell adhesion molecule-1 (VCAM-1). B-cells obtained from the lymph nodes of patients with centroblastic-centrocytic lymphoma expressed several ligands complementary to the adhesion molecules detected on FDC. These include LFA-1 alpha- and beta-chains (CD11a, CD18), and ICAM-1 (CD54). Surprisingly, monoclonal lymphocytes in the peripheral blood of patients with a leukaemic course of this lymphoma entity were devoid of these antigens. It seems likely then that neoplastic B-cells without CD11a, CD18 and CD 54 surface molecules are unable to associate with FDC and now invade other compartments. Thus, the adhesive interactions which do occur between FDC and NHL-B-cells may directly influence the peculiar growth pattern and spread of centroblastic-centrocytic lymphoma.