Necker-Enfants Malades Hospital 2 articles published in JoVE Immunology and Infection Isolation of Tonsillar Mononuclear Cells to Study Ex Vivo Innate Immune Responses in a Human Mucosal Lymphoid Tissue Nikaïa Smith1,2,3,4, Nassima Bekaddour2,3,4, Nicolas Leboulanger4,5, Yolande Richard*6, Jean-Philippe Herbeuval*2,3,4 1Institute of Molecular Virology, Ulm University Medical Center, 2CNRS UMR-8601, Centre Interdisciplinaire Chimie Biologie, 3Team Chemistry & Biology, Modeling & Immunology for Therapy, Université Paris Descartes, 4Université Paris Descartes, Sorbonne Paris Cité, 5Pediatric Otolaryngology Department, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, 6Université de Paris, Institut Cochin In the present protocol, we explain how to easily process and culture tonsillar mononuclear cells from healthy humans undergoing partial surgical tonsillectomy to study innate immune responses upon activation, mimicking viral infection in mucosal tissues. Medicine Standardized Measurement of Nasal Membrane Transepithelial Potential Difference (NPD) George M. Solomon1, Inez Bronsveld2, Kathryn Hayes3, Michael Wilschanski4, Paola Melotti5, Steven M. Rowe1, Isabelle Sermet-Gaudelus6,7 1Department of Medicine and the Gregory Fleming James Cystic Fibrosis Center, University of Alabama at Birmingham, 2Department of Pulmonology and Tuberculosis, University Medical Center Utrecht, 3Center for Experimental Medicine, Queens University, Northern Ireland, 4Hadassah Hebrew University Medical Center, Jerusalem, 5Centro Fibrosi Cistica, Azienda Ospedaliera Universitaria Integrata, 6Service de Pneumologie et Allergologie Pédiatriques and Center de Ressources et de Compétence de la Mucoviscidose, Hôpital Necker Enfants Malades, 7INSERM U 1151, Institut Necker Enfants Malades Here, we present a standardized protocol to measure the nasal potential difference (NPD). Cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial sodium channel (ENaC) function are evaluated by the change in the voltage across the nasal epithelium after superfusion of solutions that modify ion channel activity, providing an outcome measure.