New assay to detect shedding antigen with use of anti-idiotypic monoclonal antibodies.
Anti-idiotypic (Anti-Id) monoclonal antibodies (MoAbs) against anti-carcinoembryonic antigen (CEA) monoclonal antibody 5B3 (IgG1) were prepared and characterized. Five anti-Id MoAbs recognized the private idiotype of MoAb 5B3. Idiotype mapping suggested that MoAb 5B3 had at least three distinct idiotopes at its antigen combining site. Utilizing the inhibition of idiotype-anti-idiotype interaction with use of anti-Id MoAb T4-305 or T4-212, an immunoassay to detect shedding CEA was established. The results of this inhibition assay correlated with those of double determinant immunoassay and inhibition percentages linearly increased in a CEA concentration-dependent manner. Since it requires only one epitope of a given antigen molecule, this assay could be widely used for detection of shedding antigens, including tumor-associated antigens.
Tsujisaki
M
M
Department of Internal Medicine (Section 1), Sapporo Medical College, Japan.
Imai
K
K
Tokuchi
S
S
Masuya
J
J
Ishida
T
T
Adachi
M
M
Hinoda
Y
Y
Hanzawa
Y
Y
Yachi
A
A
D000818:Animals; D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen / Q000032:analysis*; D005069:Evaluation Studies as Topic; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007130:Immunoglobulin Idiotypes; D014407:Tumor Cells, Cultured / Q000276:immunology
D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D007130:Immunoglobulin Idiotypes