Biological Evaluation of 131I- and CF750-Labeled Dmab(scFv)‎-Fc Antibodies for Xenograft Imaging of CD25-Positive Tumors

Abstract EN

A Dmab(scFv)-Fc antibody containing the single chain variable fragment of a humanized daclizumab antibody and the Fc fragment of a human IgG1 antibody was produced via recombinant expression in Pichia pastoris.

The Dmab(scFv)-Fc antibody forms a dimer in solution, and it specifically binds CD25-positive tumor cells and tumor tissues.

For tumor imaging, the Dmab(scFv)-Fc antibody was labeled with the 131I isotope and CF750 fluorescent dye, respectively.

After intravenous injection of mice bearing CD25-positive tumor xenografts, tumor uptake of the 131I-Dmab(scFv)-Fc antibody was visible at 1 h, and clear images were obtained at 5 h using SPECT/CT.

After systemic administration of the CF750-Dmab(scFv)-Fc antibody, tumor uptake was present as early as 1 h, and tumor xenografts could be kinetically imaged within 9 h after injection.

These results indicate that the Dmab(scFv)-Fc antibody rapidly and specifically targets CD25-positive tumor cells, suggesting the potential of this antibody as an imaging agent for the diagnosis of lymphomatous-type ATLL.