Antigenic modulation and internalization of monoclonal antibody to human colonic carcinoma cells detected by enzyme-linked immunosorbent assay.
We studied antigenic modulation and internalization of monoclonal antibody (MAb) A7 using the enzyme-linked immunosorbent assay (ELISA) and biotin-labelled antibody-staining techniques. Incubation of the colonic SW1116 cell line with an excess of MAb A7 induced modulation of the cell-surface antigen. When the line was assayed by ELISA, a change in cellular reactivity with MAb A7 was seen after 1 hr. After 24 hr, the cellular reactivity showed a 52% decrease in absorbance. Modulation was inhibited by 0.1% sodium azide and acetone fixation, suggesting that this is an energy-dependent phenomenon. The internalization of biotinylated MAb A7 was examined. Internalized biotinylated MAb A7 was detected in cells fixed before labelling with avidin-biotin peroxidase complex. It was observed that the amount of MAb A7 which remained associated with the cell surface had decreased since A7 was internalized.
Yokota
T
T
First Department of Surgery, Kyoto Prefectural University of Medicine, Japan.
Otsuji
E
E
Noguchi
A
A
Yamaguchi
T
T
Sawai
K
K
Takahashi
T
T
D000911:Antibodies, Monoclonal / Q000378:metabolism*; D000951:Antigens, Neoplasm / Q000378:metabolism*; D001710:Biotin; D002277:Carcinoma / Q000276:immunology*; D003110:Colonic Neoplasms / Q000276:immunology*; D004705:Endocytosis; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007152:Immunologic Capping; D066298:In Vitro Techniques; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D001710:Biotin