Epitope masking of rat esophageal carcinoma tumor-associated antigen by certain coexisting glycolipid and phospholipid molecules: a potential mechanism for tumor cell escape from the host immune responses. Cancer Immunol Immunother 1994 Feb;38(2):99-106
Date
02/01/1994Pubmed ID
7508339Pubmed Central ID
PMC11038048DOI
10.1007/BF01526204Scopus ID
2-s2.0-0028123533 (requires institutional sign-in at Scopus site) 6 CitationsAbstract
A monoclonal antibody (mAb-5G) produced against a tumorigenic rat esophageal cell line, B2T, was shown to react specifically with a unique glycolipid antigen expressed on the cell surface of tumorigenic and certain non-tumorigenic, immortalized rat esophageal cell lines [Cancer Immunol Immunother 36: 94 (1993)]. In enzyme-linked immunosorbent assay experiments, mAb-5G reacted with crude lipid extracts prepared from B2T cells cultured in vitro, but showed very little reactivity with crude lipid extracts prepared from the same cell line passaged once in vivo, unless the antigen was separated from other lipid components by column or thin-layer chromatography (TLC). When a secondary tissue-culture cell line was established from the above B2T tumor tissues and serially subcultured in vitro, the percentage of positively stained cells was increased significantly in immunofluorescence assay. It was also demonstrated that the amount of extractable antigen was increased as the cells were subcultured in vitro up to passage 15, and stabilized thereafter. These results indicate the presence of certain lipid components in crude lipid extracts from B2T cells grown in vivo that are capable of interfering with antigen-antibody binding. On TLC plates, these interfering lipids were identified as phosphatidylcholine, phosphatidylserine, sphingomyelin and gangliosides. The interfering lipids did not bind the antibody, rather they appeared to interfere with antigen accessibility. These lipid substances may modify tumor cell surface antigen(s), thus protecting the tumor cells from host immune destruction.
Author List
Jamasbi RJ, Wan X, Stoner GDMESH terms used to index this publication - Major topics in bold
AnimalsAntibodies, Monoclonal
Antibodies, Neoplasm
Antigens, Neoplasm
Carcinoma
Cattle
Epitopes
Esophageal Neoplasms
Glycolipids
In Vitro Techniques
Phospholipids
Rats
Rats, Inbred F344
Tumor Cells, Cultured
