T cell retargeting using bispecific monoclonal antibodies in a rat colon carcinoma model. II. Syngeneic colon carcinoma CC531 is efficiently killed by retargeted cytotoxic T lymphocytes in vitro despite limited lysis in 51Cr release assays

Autor: G D Beun, A Gorter, Y Nooyen, C J van de Velde, G J Fleuren
Rok vydání: 1993
Předmět:
Zdroj: The Journal of Immunology. 150:2305-2315
ISSN: 1550-6606
0022-1767
Popis: We have previously described the generation of bispecific anti-TCR*anti-tumor mAb, intended for in vivo analysis of T cell retargeting in a syngeneic rat colon carcinoma model. Colon carcinoma CC531 proved to be markedly resistant to lysis by polyclonally activated, retargeted rat T lymphocytes, if measured in short term or overnight prolonged 51Cr release assays. Using cocultivation, we have now focused on another, biologically more relevant aspect of retargeted interaction: the effect on the capacity of CC531 tumor cells to survive and grow. Tumor neutralization was scored after 3 days of coculture, using a tetrazolium salt to quantify viable adherent tumor cells. Compared to 51Cr release assays, we found cocultivation to be more sensitive and more informative, as it revealed tumor cell killing at low E:T ratios, synergism of bispecific antibodies and exogenous IL-2, and free bispecific antibody-dependent recycling of effector cells. Apart from providing valuable information for future in vivo studies in this model, these data support the notion of tumor neutralization as a useful alternative for 51Cr release assays.
Databáze: OpenAIRE