Characterization of bispecific T-cell Engager (BiTE) antibodies with a high-capacity T-cell dependent cellular cytotoxicity (TDCC) assay

J Biomol Screen. 2015 Apr;20(4):519-27. doi: 10.1177/1087057114561405. Epub 2014 Dec 4.

Abstract

The Bispecific T-cell Engager (BiTE) antibody modality is a clinically validated immunotherapeutic approach for targeting tumors. Using T-cell dependent cellular cytotoxicity (TDCC) assays, we measure the percentage of specific cytotoxicity induced when a BiTE molecule engages T-cells, redirects T-cell mediated cytolysis, and ultimately kills target cells. We establish a novel luminescence-based TDCC assay quantified by measuring cell viability via constitutive expression of luciferase. The luciferase-based TDCC assay performance is valid and comparable to an adenosine triphosphate (ATP)-based detection method. We demonstrate that the luciferase-based TDCC assay is an efficient homogeneous assay format that is amenable to both suspension and adherent target cells. The luciferase-based TDCC assay eliminates the need for plate-washing protocols, allowing for higher-throughput screening of BiTE antibodies and better data quality. Assay capacity is also improved by performing serial dilutions of BiTE antibodies in 384-well format with an automated liquid handler. We describe here a robust, homogeneous TDCC assay platform with capacity for in vitro assessment of BiTE antibody potency and efficacy using multiple tumor cell lines and T-cell donors.

Keywords: Bispecific T-cell Engager (BiTE®); T-cell dependent cellular cytotoxicity (TDCC); cell viability; cell-based assay; luciferase.

MeSH terms

  • Cytotoxicity, Immunologic*
  • Humans
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology*