Research Institute of the McGill University Health Centre 3 articles published in JoVE Immunology and Infection Processing of Bronchoalveolar Lavage Fluid and Matched Blood for Alveolar Macrophage and CD4+ T-cell Immunophenotyping and HIV Reservoir Assessment Syim Salahuddin*1,2, Elaine Thomson*1,2,3, Oussama Méziane1,2, Omar Farnos2, Amélie Pagliuzza5, Nicolas Chomont5,6, Ron Olivenstein1, Cecilia Costiniuk1,3,4, Mohammad-Ali Jenabian2,3,6 1Research Institute McGill University Health Centre, 2Department of Biological Sciences, Université de Québec à Montréal, 3Department of Microbiology & Immunology, McGill University, 4Department of Medicine, Division of Infectious Diseases, McGill University, 5 We describe a method for processing bronchoalveolar lavage fluid and matched peripheral blood from chronically HIV-infected individuals on antiretroviral therapy to assess pulmonary HIV reservoirs. These methods result in the acquisition of highly pure CD4 T cells and alveolar macrophages that may subsequently be used for immunophenotyping and HIV DNA/RNA quantifications by ultrasensitive polymerase chain reaction. Biology Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death Snezana Vujicic*1,2, Lanfei Feng*1,2, Angelika Antoni3, Joyce Rauch4, Jerrold S. Levine1,2,5 1Section of Nephrology, Department of Medicine, University of Illinois at Chicago, 2Section of Nephrology, Department of Medicine, Jesse Brown Veterans Affairs Medical Center, 3Department of Biology, Kutztown University of Pennsylvania, 4Division of Rheumatology, Department of Medicine, Research Institute of the McGill University Health Centre, 5Department of Microbiology & Immunology, University of Illinois at Chicago Here, we present a protocol for the determination of intracellular signaling events induced in viable cells by physical interaction with adjacent dead or dying cells. The protocol focuses on signaling events induced by receptor-mediated recognition of the dead cells, as opposed to their phagocytic uptake or release of soluble mediators. Biology High Resolution Whole Mount In Situ Hybridization within Zebrafish Embryos to Study Gene Expression and Function Babykumari P. Chitramuthu1,2, Hugh P. J. Bennett1,2 1Endocrine Research Laboratory and Department of Medicine, Royal Victoria Hospital, 2McGill University Health Centre Research Institute The zebrafish, a small tropical fish, has become a popular model for studying gene function during vertebrate development and disease. The temporal and spatial expression of target genes can be determined by in situ hybridization. Our improved protocol allows for the detection of low abundant transcripts with low non-specific background signal.