Administration of BiMAb-retargeted T cells in a rat hepatic metastases colon tumour model results in T-cell tumour infiltration independent of the route of administration

In this study, cultured T cells, pre-incubated with the bispecific monoclon al antibody (BiMAb) R73IgG1 x CC52IgG1 were adoptively transferred, via sys temic and regional routes, to rats bearing day 10 hepatic metastases of the CC531 adenocarcinoma of the colon to investigate the role of the route of administration in tumour infiltration by these BiMAb-retargeted effector ce lls. The BiMAb, directed against the T-cell receptor and the tumour-associa ted antigen CC52, were used to crosslink CC531 tumour cells and T cells to induce tumour cell lysis. Retargeted T cells were administered via the jugu lar vein, hepatic artery or the portal vein. The number of BiMAb-retargeted T cells that reached the liver tumours was independent of the route of adm inistration. There was also no difference between the number of T cells tha t reached the portal tracts, central veins of parenchyma of the liver, afte r loco-regional or systemic administration. These findings are in contrast to the interleukin (IL)-2 activated NK (A-NK) cells biodistribution studies earlier performed in the same animal model in our laboratory. Compared wit h A-NK cells, a lower number of BiMAb-retargeted T cells reached the tumour s, irrespective of their route of administration while for A-NK cells, ther e was an advantage of administration via the hepatic artery.