MONOCLONAL ANTIBODY-4C7 RECOGNIZES AN ENDOTHELIAL BASEMENT-MEMBRANE COMPONENT THAT IS SELECTIVELY EXPRESSED IN CAPILLARIES OF LYMPHOID FOLLICLES

In order to define compartment-related structures within the extracell ular matrix of human lymphoid organs, monoclonal antibodies (MAbs) wer e generated by immunizing mice with stromal fragments of human tonsils . One MAb (4C7) was selected which recognized an endothelial basal mem brane component that is selectively expressed in capillaries of lympho id follicles. The epitope was also present in follicles within chronic ally inflamed synovial membrane and in a hyperplastic thymus of a pati ent with myasthenia gravis. B-cell non-Hodgkin's lymphomas with a foll icular growth pattern expressed the antigen in neoplastic follicles. w hereas diffuse growing lymphomas lacked the antigen. The restricted di stribution pattern suggests involvement of the 4C7-defined antigen in the organization of the follicular compartment within human lymphoid t issue.