Emmet Francis, a 1st year Ph.D. student in Biomedical Engineering under the mentorship of Dr. Volkmar Heinrich, was recently selected for the 2018 NSF Graduate Research Fellowship Program.
The Heinrich Lab uses glass micropipettes to hold and manipulate human immune cells and pathogenic particles. This technique gives them a close-up view of human immune cells in action, reaching out towards pathogens via chemotaxis or consuming them via phagocytosis. In his past research, Emmet performed these experiments with human neutrophils (a type of white blood cell) while simultaneously using fluorescence to monitor the free calcium concentration inside the cell. Neutrophils are known to exhibit large, rapid increases in calcium levels (“calcium bursts”) during a variety of processes from arrest on endothelial cells in blood vessels to phagocytosis of pathogens. However, Emmet found that that the calcium level remains at a constant, low level during adhesion-free chemotaxis, indicating that adhesion may be a prerequisite to calcium bursts. This suggests a mechanoregulatory role for calcium signaling in human neutrophils. In his NSF proposal, “Interrelating Mechanical Behavior and Calcium Bursts in Human Neutrophils”, Emmet laid out his Ph.D. research plan to explore the relationship between the mechanical behavior of human neutrophils during chemotaxis and phagocytosis and the calcium signaling events within the cell. In this project, Emmet plans to expand into new research areas including computational modeling and actin imaging.