BME Seminar Series: Volkmar Heinrich, Ph.D.

Tuesday, November 4, 2014
8:30 a.m.

Goergen Hall 101 (Sloan Auditorium)

“Controlled One-on-One Encounters Between Immune Cells and Microbes Offer a New Window into Innate Immunity and the Pathogenesis of Infections”

Volkmar Heinrich, Ph.D.
Department of Biomedical Engineering
University of California, Davis

Abstract: Infectious, autoimmune, and chronic inflammatory diseases present a rising threat, underlining the need for a deeper understanding of how the immune system recognizes—or fails to recognize—pathogens.  Many prevailing gaps in our knowledge can be attributed to an imbalance between the cross-disciplinary nature of the immune response and a lack of truly interdisciplinary studies of the underlying mechanisms.  Moreover, there is mounting evidence that insight into the human immune system cannot be reliably inferred from animal models or cell lines.

Immune cells are perhaps the most relevant functional units of the immune system.  Mechanistic analyses of single-live-cell encounters with microbes deserve a front-and-center place in the study of host-pathogen interactions.  To unravel how the innate immune system coordinates different stages of the cell response to pathogens, an integrative strategy should examine the spectrum of mechanisms by which immune cells home in on (by chemotaxis), take hold of (through adhesion), and internalize (by phagocytosis) microbes.  We here discuss new, interdisciplinary approaches to study independently single-cell chemotaxis, adhesion, and phagocytosis by analyzing one-on-one encounters between immune cells and bacteria or fungi.  These experiments use non-adherent cells, thus preventing premature cell activation.  They offer unprecedented control over cell-microbe contacts and have a time resolution of fractions of a second.  They also facilitate an essentially axisymmetric configuration of the cell-microbe pair, which is viewed from the side, allowing us to visualize the interaction with unique clarity.  These experiments have been validated with various types of human immune (and other) cells, and have already revealed insight into cellular behavior that had been inaccessible to traditional techniques.