Open AccessProperties of Mouse Melanoma Antigen and Its Secretion Mechanism from the Cell Surface
Author(s) -
Kuwabara Ichiro,
Tagawa Masatoshi,
Harada Yoshitada,
Ito Toshihiro,
Taniguchi Masaru
Publication year - 1989
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.1989.tb01637.x
Subject(s) - antigen , melanoma , tunicamycin , epitope , cytotoxic t cell , microbiology and biotechnology , glycoprotein , secretion , glycosylation , biology , cell culture , immune system , chemistry , immunology , biochemistry , cancer research , in vitro , apoptosis , genetics , unfolded protein response
We analyzed the biochemical properties and biological significance of the melanoma antigen secreted in the culture supernatants of B16 melanoma cells. The 80 kilodalton (kd) molecule bearing the epitopes of mouse melanoma antigen was found to associate noncovalently with an 18 kd moiety in the culture supernatants as well as on the cell surface. Tunicamycin treatment of B16 cells did not affect the expression of the 69 kd nonglycosylated form of the 80 kd molecule but did abolish the association between the two molecules on the cell surface. We could not detect this antigen as a soluble form when the N‐linked glycosylation was inhibited. Therefore, the glycosylation of the 80 kd molecule is essential for the formation of the 80 kd/18 kd complex and also for the secretion. Moreover, the affinity‐purified melanoma antigen from the supernatants could induce anti‐melanoma suppressor cells which block the generation of cytotoxic T lymphocytes against melanoma cells. Thus, the 80 kd glycoprotein as a soluble melanoma antigen performed a pivotal function in the escape mechanisms of melanoma cells from the host immune surveillance system.