Anti-tumor activity of T-2 toxin-conjugated A7 monoclonal antibody (T-2-A7 MoAb) against human colon carcinoma.
Monoclonal antibody A7 (A7 MoAb), from splenocytes of a mouse immunized against human colorectal carcinoma, was used as a T-2 toxin (T-2) carrier targeting colon cancer. T-2 was converted to T-2 hemiglutarate by glutaric anhydride treatment, and T-2-A7 MoAb conjugates containing up to 20 T-2 per antibody molecule were obtained from the antibody and T-2 hemiglutarate activated with N-hydroxysuccinimide. The in vitro cytotoxicity against human colon cancer (LS174T) cells indicated that the conjugates were markedly less toxic than the toxin itself. The immunoreactivity was evaluated from the in vitro binding activity of A7 MoAb with LS174T cells, and from the in vivo localization in LS174T-bearing nude mice; it remained essentially intact after conjugation with T-2. The efficacy of the T-2-A7 MoAb conjugate was tested against LS174T-bearing nude mice. The conjugate significantly suppressed the growth of the tumor in comparison with both phosphate-buffered saline and free T-2. These results suggest that the conjugate of T-2 with A7 MoAb might be useful as a selective immunotoxin for cancer immunotherapy, with less serious side effects than T-2.
Kojima
S
S
Research Institute for Biosciences, Science University of Tokyo, Chiba, Japan.
Nakamura
N
N
Ueno
Y
Y
Yamaguchi
T
T
Takahashi
T
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism / Q000627:therapeutic use; D003110:Colonic Neoplasms / Q000628:therapy*; D005260:Female; D006801:Humans; D000922:Immunotoxins / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D013605:T-2 Toxin / Q000627:therapeutic use*; D014018:Tissue Distribution; D014183:Transplantation, Heterologous
D000911:Antibodies, Monoclonal; D000922:Immunotoxins; D013605:T-2 Toxin