Expression of sialyl Le~x, sialyl Le~a, Le~x and Le~y glycotopes in secreted human ovarian cyst glycoproteins

摘要

Human blood group A, B, H, Ii, Le~a and Le~b antigens and their determinants expressed on ovarian cyst glycoproteins have been studied for over five decades. However, little is known about sialyl Le~x and sialyl Le~a glycotopes, which play essential roles in normal immunity, inflammation, and cancer cell metastasis. Furthermore, Le~x and Le~y were classified as glycotopes of unknown genes. Identification of these Lewis epitopes was hampered by the lack of specific antibodies. In this study, the occurrence of sialyl Le~x, sialyl Le~a, Le~x and Le~y reactivities in cyst glycoproteins was characterized by enzyme-linked immunosorbent assays. The results indicated that most human ovarian cyst glycoproteins carried Le~x (8/25) and/or Le~y (17/25) glycotopes. The expression (epitopes) of the new genes described in previous reports are Le~x and Le~y glycotopes; the reactivities of sialyl Le~x and sialyl Le~a glycotopes in secreted cyst glycoproteins may be affected by the conditions of purification; the relationship between Le~y and human blood group ABH was confirmed; recognition profiles of sialyl Le~x, sialyl Le~a, Le~x and Le~y present in the carbohydrate chains of water-soluble cyst glycoproteins were illustrated; possible attachments of glycotopes to the internal carbohydrate complex of cyst glycoproteins have been reconstructed; proposed biosynthetic pathways for the formation of sialyl Le~a, sialyl Le~x, Le~x, Le~y, Ale~y and Ble~y determinant structures on Type I and Type II core structures of human ovarian cyst glycoproteins are also included in this study.