VERY LATE ANTIGEN (VLA) EXPRESSION BY NORMAL AND NEOPLASTIC HUMAN PLASMA-CELLS - INCLUDING AN ASSESSMENT OF ANTIBODIES SUBMITTED TO THE 5THINTERNATIONAL WORKSHOP ON LEUKOCYTE DIFFERENTIATION ANTIGENS USING HUMAN MYELOMA CELL-LINES

The biology of normal plasma cells and the pathophysiology of human mu ltiple myeloma remain poorly understood. Functional assays are scarce and at present cell phenotyping is providing the most information abou t how human plasma cells may behave. Three different types of human pl asma cells: normal, fresh neoplastic myeloma cells and plasma cell lin es, have been studied for their reactivity with antibodies to the beta -1 integrins (Very Late Antigens; VLAs), including a panel obtained fr om the Vth International Workshop on Leucocyte Differentiation Antigen s. Most plasma cell targets express VLA-4 (CD49d positive) and the com mon beta chain recognized by CD29. CD49e (VLA-5) was occasionally posi tive. Other VLAs were not usually expressed. These data suggest the wi de use by plasma cells of VLA-4, possibly as a ligand with fibronectin and high endothelial venules (HEV). Of other adhesion structures expr essed by plasma cells, only CD44 is seen as frequently, and this is al so a HEV ligand. Copyright (C) 1996 Elsevier Science Ltd.