title: Label-free identification of activated T lymphocytes through tridimensional microsensors on chip.
abstract: Label-free approaches to assess cell properties ideally suit the requirements of cell-based therapeutics, since they permit to characterize cells with minimal perturbation and manipulation, at the benefit of sample recovery and re-employment for treatment. For this reason, label-free techniques would find sensible application in adoptive T cell-based immunotherapy. In this work, we describe the label-free and single-cell detection of in vitro activated T lymphocytes in flow through an electrical impedance-based setup. We describe a novel platform featuring 3D free-standing microelectrodes presenting passive upstream and downstream extensions and integrated into microfluidic channels. We employ such device to measure the impedance change associated with T cell activation at electrical frequencies maximizing the difference between non-activated and activated T cells. Finally, we harness the impedance signature of unstimulated T cells to set a boundary separating activated and non-activated clones, so to characterize the selectivity and specificity of the system. In conclusion, the strategy here proposed highlights the possible employment of impedance to assess T cell activation in label-free.
authors.affiliation: Laboratory of Life Sciences Electronics - Swiss Federal Institute of Technology (EPFL), Lausanne CH-1015, Switzerland.
authors.forename: Enrica
authors.initials: E
authors.lastname: Rollo
authors.affiliation: Laboratory of Life Sciences Electronics - Swiss Federal Institute of Technology (EPFL), Lausanne CH-1015, Switzerland.
authors.forename: Enrico
authors.initials: E
authors.lastname: Tenaglia
authors.affiliation: Ludwig Center for Cancer Research - University of Lausanne (UNIL), CH-1066, Switzerland.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Genolet
authors.affiliation: CMIC "Giulio Natta", LaBS - Laboratory of Biological Structure Mechanics - Politecnico di Milano, I-20133, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Bianchi
authors.affiliation: Ludwig Center for Cancer Research - University of Lausanne (UNIL), CH-1066, Switzerland.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Harari
authors.affiliation: Ludwig Center for Cancer Research - University of Lausanne (UNIL), CH-1066, Switzerland.
authors.forename: George
authors.initials: G
authors.lastname: Coukos
authors.affiliation: Laboratory of Life Sciences Electronics - Swiss Federal Institute of Technology (EPFL), Lausanne CH-1015, Switzerland. Electronic address: carlotta.guiducci@epfl.ch.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Guiducci
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D017097:Electric Impedance; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D059010:Single-Cell Analysis / Q000379:methods*; D013601:T-Lymphocytes / Q000737:chemistry / Q000276:immunology*
keywords: 3D electrodes; Electrochemical impedance; Immunotherapy; Lab-on-chip devices; Microelectrodes; Microfluidic flow cytometry; Microfluidics; T cells