Construction of a conventional non-radioisotope method to quantify HM1.24 antigens: correlation of HM1.24 levels and ADCC activity of the humanized antibody against HM1.24.
A humanized monoclonal antibody (mAb) against HM1.24 (AHM) caused antibody-dependent cellular cytotoxicity (ADCC) against multiple myeloma (MM) cells. Here, we constructed a conventional non-radioisotope method that quantifies the amount of HM1.24 using fluorescein-labeled AHM. More than 10(4) molecules/cell of HM1.24 were detected in 12 out of 14 patients' MM cells, and a linear correlation was found between ADCC by AHM and the amounts of HM1.24. Thus, AHM is likely to be more efficacious against MM cells with high levels of HM1.24. This conventional non-RI method to quantify HM1.24 will be useful to select patients most likely to respond to AHM.
Kawai
Shigeto
S
Pharmaceutical Research Department III, Chugai Pharmaceutical Co. Ltd., 200 Kajiwara, Kamakura, Kanagawa 247-8530, Japan.
Koishihara
Yasuo
Y
Iida
Shin-ichiro
S
Ozaki
Shuji
S
Matsumoto
Toshio
T
Kosaka
Masaaki
M
Yamada-Okabe
Hisafumi
H
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D015703:Antigens, CD / Q000032:analysis* / Q000276:immunology; D045744:Cell Line, Tumor; D019793:Fluorescein / Q000737:chemistry; D058851:GPI-Linked Proteins; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008562:Membrane Glycoproteins / Q000032:analysis* / Q000276:immunology; D009101:Multiple Myeloma / Q000276:immunology*; D012016:Reference Values; D015203:Reproducibility of Results; D000074010:Bone Marrow Stromal Antigen 2
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D019793:Fluorescein; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; C094572:BST2 protein, human; D000074010:Bone Marrow Stromal Antigen 2