Neutrophil Microscopy and Quantitative Imaging Core B

SUMMARY Neutrophils are the first line of defense against bacteria and fungi and induce inflammation. The study of the molecular mechanisms mediating neutrophil activation is therefore of fundamental importance. Visualizing these mechanisms requires unique, state-of-the-art technologies and approaches. To achieve this, Core B is designed to coordinate, design, develop and execute new technical approaches applied to the understanding of neutrophil biology in inflammation. Core B will work with all three Projects and will provide relevant imaging and microscopy assays in mice and human samples. The core utilizes available cutting-edge technology to implement new experimental approaches and to help elucidate the intricate cell biology processes proposed in research plans of Projects 1 (Dr. Hedrick), Project 2 (Dr. Catz) and Project 3 (Dr. Hoffman). To this end, we will have the dedicated effort of a Technology Core director (Dr. Kiosses) who will allocate specific time and efforts to support the goals of the PPG. Core B optimizes the workflows of neutrophil imaging, image quantification and data sharing for all projects. It provides stringent quality controls and ensures uniformity of performance of multiple key technologies applied to the study of neutrophils and precursors in the setting of coronary artery disease. Core B will implement unique live-cell approaches to study neutrophil vesicular trafficking, cytoskeleton remodeling and cell death pathways. Core B is technically and conceptually innovative because it utilizes, neutrophil-dedicated, novel approaches that include super-resolution microscopy and quantitative analyses of neutrophil dynamics to elucidate neutrophil functions and to elucidate their role in inflammation. In relationship with Project 1, Core B will identify neutrophils and their precursors in atherosclerotic plaques during NETosis and pyroptosis in conditions of inflammasome activation at various stages of plaque development in high-fat diet, both ex-vivo and in vivo using the ApoE-/- Western diet model of CAD mice. In association with Project 2, Core B will utilize single-molecule super-resolution microscopy and Total Internal Reflection Fluorescence Microscopy to study molecular mechanisms regulating vesicular trafficking and actin remodeling in neutrophil precursors. Core B will also utilize Correlated-Light Electron Microscopy (CLEM) to characterize the newly identified precursor-specific granules (PSGs). In collaboration with Project 3, Core B will examine three-dimensional localization and spatial changes in the mitochondrial network as the cells undergo apoptotic or necroptotic cell death in both neutrophils and their precursors from mouse models and human neutrophils from patients with CAD. In conclusion, Core B is uniquely designed to use the valuable technology available in La Jolla to the fullest extent possible to maximize neutrophil-dedicate research and productivity associated with the PPG.