Complexity of expression of antigenic determinants, recognized by monoclonal antibodies HMFG-1 and HMFG-2, in normal and malignant human mammary epithelial cells.

作者：Joy Burchell, Helga Durbin, Joyce Taylor‐Papadimitriou · 发表于：The Journal of Immunology · 年份：1983 · DOI：10.4049/jimmunol.131.1.508 · 被引用次数：333 · 研究领域：Estrogen and related hormone effects、Monoclonal and Polyclonal Antibodies Research

Abstract The monoclonal antibodies HMFG-1 and HMFG-21 are produced by hybridomas derived by fusing spleen cells of mice immunized with delipidated preparations of the human milk fat globule. Enzyme-linked immunosorbent (ELISA) assays of Western blots prepared from gels separating components of the milk fat globule showed that both antibodies recognize determinants fouinn dh igh molecular weight components (>400K). Lectin-blocking experiments indicated that both antibodies recognizeo ligosaccharide sequences containing galactose, N-acetyl glucosamine, and, possibly, N-acetyl galactosamine. However, the determinant recognized by HMFG-1 is different from the determinant recognbizye dH MFG-2,w hich may contain or be adjacent to a nonterminal sialic acid residue. The expression of these antigenic determinants by normal mammary epithelial cells cultured from milk (HumE) and by a breast cancer cell line (T47D), was studied. In a live cell, radioimmune assay lower levels of HMFG-1 than HMFG-2 were required for effective binding to HumE cells, whereas HMFG-2 bound to T47D cells at lower concentrations than HMFG-1. Kinetic experiments using 125I-Iabeled antibodies showed that high affinity binding sites for both antibodies are present on HumE cells, but the number of sites binding HMFG-1 is greater than the number of sites binding HMFG-2. Thkei netics of dissociation of labeled antibodies from T47D cells sug gested the presenceo f several sites with different affinities for each antibo...