title: Measuring cytotoxicity by bioluminescence imaging outperforms the standard chromium-51 release assay.
abstract: The chromium-release assay developed in 1968 is still the most commonly used method to measure cytotoxicity by T cells and by natural killer cells. Target cells are loaded in vitro with radioactive chromium and lysis is determined by measuring chromium in the supernatant released by dying cells. Since then, alternative methods have been developed using different markers of target cell viability that do not involve radioactivity. Here, we compared and contrasted a bioluminescence (BLI)-based cytotoxicity assay to the standard radioactive chromium-release assay using an identical set of effector cells and tumor target cells. For this, we stably transduced several human and murine tumor cell lines to express luciferase. When co-cultured with cytotoxic effector cells, highly reproducible decreases in BLI were seen in an effector to target cell dose-dependent manner. When compared to results obtained from the chromium release assay, the performance of the BLI-based assay was superior, because of its robustness, increased signal-to-noise ratio, and faster kinetics. The reduced/delayed detection of cytotoxicity by the chromium release method was attributable to the association of chromium with structural components of the cell, which are released quickly by detergent solubilization but not by hypotonic lysis. We conclude that the (BLI)-based measurement of cytotoxicity offers a superior non-radioactive alternative to the chromium-release assay that is more robust and quicker to perform.
authors.affiliation: Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, United States of America ; Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors.forename: Mobin A
authors.initials: MA
authors.lastname: Karimi
authors.affiliation: Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, United States of America.
authors.forename: Eric
authors.initials: E
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Bachmann
authors.affiliation: Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, United States of America.
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Salicioni
authors.affiliation: Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America.
authors.forename: Edward M
authors.initials: EM
authors.lastname: Behrens
authors.affiliation: Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors.forename: Taku
authors.initials: T
authors.lastname: Kambayashi
authors.affiliation: Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, United States of America.
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Baldwin
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002460:Cell Line; D002860:Chromium Radioisotopes / Q000378:metabolism; D003601:Cytotoxicity Tests, Immunologic / Q000379:methods*; D006801:Humans; D007700:Kinetics; D008156:Luciferases; D008163:Luminescent Measurements / Q000379:methods*; D051379:Mice
chemical_list: D002860:Chromium Radioisotopes; D008156:Luciferases