Abstract
Soluble isoforms of various adhesion molecules have recently been found in the circulation, but the physiologic effects of such molecules are still unconfirmed. Our earlier study suggests that the serum level of the 70- to 80-kDa form of CD44 (sCD44) parallels the clinical treatment response in patients with lymphoma. In the present study we investigated the origin and the function of sCD44 in non-Hodgkin's lymphoma. Both peripheral blood and tumor lymphocytes were able to shed soluble CD44 in cell culture. In a SCID mouse model, transplanted Burkitt lymphoma (Namalwa) cells transfected with human CD44 shed soluble CD44. In binding studies sCD44 was able to adhere to hyaluronate and fibronectin, and moreover, sCD44 was able to block the binding of hyaluronate to CD44 on the cell surface and to block the binding of lymphocytes to high endothelial venules, suggesting that sCD44 retains its biological activity although it does not contain the cytoplasmic tail. In conclusion, sCD44 is biologically active and is at least partially shed by lymphoma cells in non-Hodgkin's lymphoma patients.
- Copyright © 1997 by American Association of Immunologists
Pay Per Article - You may access this article (from the computer you are currently using) for 1 day for US$37.50
Regain Access - You can regain access to a recent Pay per Article purchase if your access period has not yet expired.