A streptococcal preparation (OK-432) enhances monoclonal antibody NCC-ST-421 cytotoxicity against human colon cancer.
The murine IgG3 monoclonal antibody NCC-ST-421 (ST-421), raised against human gastric cancer, shows strong reactivity with the Le(a)/Le(a) (al-fucosylated extended type 1 chain) antigen expressed on gastrointestinal (GI) cancer cells. ST-421 is capable of mediating both antibody-dependent cellular cytotoxicity (ADCC) by human peripheral blood lymphocytes (PBL), and complement dependent cytotoxicity (CDC). We investigated combination immunotherapy with OK-432, a streptococcal preparation, and ST-421 in vitro and in vivo. ADCC against Colo 205 (a human colon cancer cell line) was enhanced 2 to 3 fold after preincubation of PBL with OK-432 in vitro. These effect's were strongest when PBL were preincubated with OK-432 at a concentration of 0.5 ng/ml for 24 hours. In vivo, a human colon cancer xenograft model exhibited significant growth suppression after combined treatment with ST-421 and OK-432. Such combination immunotherapy may therefore be clinically useful in GI cancer.
Kawano
Y
Y
Department of Surgery, School of Medicine, Keio University, Tokyo, Japan.
Watanabe
M
M
Kubota
T
T
Nishibori
H
H
Kurihara
N
N
Teramoto
T
T
Kitajima
M
M
D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage*; D000912:Antibodies, Neoplasm / Q000008:administration & dosage*; D000920:Antibody-Dependent Cell Cytotoxicity; D000951:Antigens, Neoplasm / Q000276:immunology; D004357:Drug Synergism; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D017737:Macrophages, Peritoneal / Q000276:immunology; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000628:therapy*; D010844:Picibanil / Q000008:administration & dosage*; D014407:Tumor Cells, Cultured
D000276:Adjuvants, Immunologic; D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D010844:Picibanil