EXPRESSION OF LOW-LEVELS OF PERIPHERAL LYMPH NODE-ASSOCIATED VASCULAR ADDRESSIN IN MUCOSAL LYMPHOID-TISSUES - POSSIBLE RELEVANCE TO THE DISSEMINATION OF PASSAGED AKR LYMPHOMAS

Lymphoid tumors display a wide variety of growth patterns in vivo, from that of a solitary extralymphoid tumor, to a general involvement of all lymphoid organs. Normal lymphocytes are uniquely mobile cells continuously recirculating between blood and lymph throughout much of their life cycle. Therefore, it is reasonable to propose that disseminating malignant lymphocytes may express recirculation characteristics or homing properties consistent with that of their normal lymphoid counterparts. Trafficking of lymphocytes involves the expression and recognition of both lymphocyte homing receptors and their opposing receptors on endothelium, the vascular addressins. These cell surface elements direct the tissue‐selective localization of lymphocyte subsets in vivo into organized lymphoid organs and sites of chronic inflammation where specific binding events occur between lymphocytes and the endothelium of specialized high endothelial venules (HEV). Ina recent murine study of 13 lymphoma lines, we found that lymphomas that bind well to high endothelial venules, in the Stamper‐Woodruff in vitro assay (an assay of lymphocyte binding to venules in frozen sections of peripheral lymph nodes or Peyer's patches), spread hematogenously to all high endothelial venule bearing lymphoid organs, whereas non‐binding lymphomas did not. In some cases lymphomas that bound with a high degree of selectivity to peripheral lymph node (PLN) high endothelial venules exhibited only limited organ preference of metastasis, involving the mucosal lymphoid organs Peyer's patches (PP) in addition to the peripheral lymph nodes of adoptive recipients. Here we demonstrate that Peyer's patch high endothelial venules express a low but functional level of peripheral lymph node addressin (MECA‐79) that can be recognized by lymphomas expressing the peripheral lymph node homing receptor (MEL‐14 antigen). Utilization of the peripheral lymph node associated endothelial cell recognition system could explain the ability of lymphoid neoplasms, selectively expressing lymph node homing receptors, to disseminate to both periph‐eral lymph nodes and to organized mucosal lymphoid tissues in vivo. Copyright © 1990 Wiley‐Liss, Inc.