title: Visualization and quantification of cytotoxicity mediated by antibodies using imaging flow cytometry.
abstract: Conventional approaches for the detection of antibody dependent cell-mediated cytotoxicity (ADCC) activity rely on quantification of the release of traceable compounds from target cells or flow cytometry analysis of population-wide phenomena. We report a new method for the direct imaging and quantification of ADCC of cancer cells. The proposed method using imaging flow cytometry combines the statistical power of flow cytometry with the analytical advantages of cell imaging, providing a novel and more comprehensive perspective of effector/target cell interactions during ADCC events. With this method we can quantify and show in detail the morphological changes in target and effector cells, their apoptotic index, the physical interaction between effector and target cells, and a directional transfer of cytosolic contents from effector to target cells. As a model system we used the therapeutic anti-CD20 antibody rituximab to target CFSE labeled Ramos human Burkitt's lymphoma cells, to CMTPX-labeled human monocytic U-937 effector cells. We expect that similar studies using different effector and target cell populations may contribute to the pre-clinical evaluation of therapeutic antibodies and help to identify mechanisms that could be beneficial in the immunotherapy of cancer.
authors.affiliation: Division of Surgical Oncology, Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, USA. ghelguera@ffyb.uba.ar
authors.forename: Gustavo
authors.initials: G
authors.lastname: Helguera
authors.forename: José A
authors.initials: JA
authors.lastname: Rodríguez
authors.forename: Rosendo
authors.initials: R
authors.lastname: Luria-Pérez
authors.forename: Shannon
authors.initials: S
authors.lastname: Henery
authors.forename: Paul
authors.initials: P
authors.lastname: Catterton
authors.forename: Carlos
authors.initials: C
authors.lastname: Bregni
authors.forename: Thaddeus C
authors.initials: TC
authors.lastname: George
authors.forename: Otoniel
authors.initials: O
authors.lastname: Martínez-Maza
authors.forename: Manuel L
authors.initials: ML
authors.lastname: Penichet
mesh_terms: D058846:Antibodies, Monoclonal, Murine-Derived / Q000494:pharmacology*; D000920:Antibody-Dependent Cell Cytotoxicity / Q000187:drug effects* / Q000276:immunology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D002051:Burkitt Lymphoma / Q000188:drug therapy* / Q000276:immunology* / Q000473:pathology; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015203:Reproducibility of Results; D000069283:Rituximab; D020298:U937 Cells
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D000069283:Rituximab