The induction of cytotoxicity by a bispecific antibody against CEA positive cell line, in vitro.
A mouse anti-human carcinoembryonic antigen (CEA) x anti-human CD3 bispecific antibody, AB5C10*UCHT1, was developed. This antibody-heteroconjugate was chemically prepared by cross-linking the AB5C10 monoclonal antibody reactive with human CEA with the monoclonal antibody, UCHT1, which binds to CD3 on human T-lymphocytes. The AB5C10*UCHT1 recognized both CEA expressed on the KATOIII cell line and CD3 expressed on T-lymphocytes, as determined using flowcytometry. Next, AB5C10*UCHT1-mediated cytolysis was analyzed by 51Cr-release assay. When 51Cr-labeled target KATOIII cells were incubated for 6 h with effector cells that had been pretreated with AB5C10*UCHT1 for 60 min at 4 degrees C, the percentage specific lysis was significantly increased compared to that of untreated effector cells. Using peripheral blood mononuclear cells (PBMC) and lymphokine-activated killer (LAK) cells pretreated with AB5C10*UCHT1 for effector cells, the percentage specific lysis was determined to be 16.3% and 57.4% at effector: target (E:T) ratios of 100:1 and 12.5:1, respectively. On the other hand, the percentage specific lysis of untreated PBMC and LAK cells determined to be 3.0% and 35.8% at E:T ratios of 100:1 and 12.5:1, respectively. The minimum effective dose of AB5C10*UCHT1 required for antibody-mediated cytotoxicity was 0.1 mu g/ml. The results of this study suggest that AB5C10*UCHT1 could be useful for augmenting the cytotoxicity of CD3-positive T-cells against CEA-positive target cells in vitro.
Hideshima
T
T
Second Department of Surgery, School of Medicine, Fukuoka University, Nanakuma, Jonan-ku, Japan.
Iwasaki
A
A
Baba
M
M
Yamashita
Y
Y
Shirakusa
T
T
Okada
H
H
D000818:Animals; D018033:Antibodies, Bispecific / Q000276:immunology / Q000494:pharmacology*; D017252:CD3 Complex / Q000276:immunology*; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects / Q000276:immunology; D005434:Flow Cytometry; D051379:Mice; D008807:Mice, Inbred BALB C; D013274:Stomach Neoplasms; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000276:immunology
D018033:Antibodies, Bispecific; D017252:CD3 Complex; D002272:Carcinoembryonic Antigen