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Use of combination of monoclonal antibodies directed against three distinct epitopes of a tumor‐associated antigen: Analysis of cell binding and internalization
Author(s) -
Casalini Patrizia,
Mezzanzanica Delia,
Canevari Silvana,
Della Torre Gabriella,
Miorn Silvia,
Colnaghi Maria Ines,
Matzku Siegfried
Publication year - 1991
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910480222
Subject(s) - internalization , monoclonal antibody , epitope , endocytosis , biology , antigen , microbiology and biotechnology , in vitro , antibody , chemistry , biochemistry , cell , immunology
Abstract Three monoclonal antibodies (MAbs), MOv17, MOv 18 and MOv19 with tumor‐restricted specificity for human ovarian carcinoma, were tested alone or in double combination with the aim of analyzing their binding and internalization behavior on different In vitro cell lines. Biochemical studies indicated that the 3 MAbs were directed against 3 epitopes of the same 38 kDa surface molecule. By immuno‐electron‐microscopy they exhibited a different internalization behavior since MOv17 Induced evident endocytosis through coated vesicles, whereas MOv18 gave rise to occasional uncoated vesicles and MOv19 was completely unable to promote internalization of the relevant molecule. When tested 2 by 2 there was a binding synergy in one of the 9 possible combinations ( 125 I‐labelled MOv18 and unlabelled MOv19), but no change in the internalization behavior. The binding synergy, which was highly reproducible, was temperature‐dependent and was also evident on glutaraldehyde‐fixed cells. A metabolism involvement is therefore unlikely. This could be attributed to an easier accessibility of the CaMOv18 due to a conformational change of the molecule after MOv19 MAb binding.