Projects | Tafesse Lab

Tafesse Lab focuses on identifying and characterizing the host factors that are used by pathogens to secure invasion, persistence and propagation. We are especially interested in studying the role of cellular lipids in bacterial and/or viral pathogenesis and their significance on innate and adaptive immunity. We employ genome-wide genetic screens, various lipidomic analysis techniques and state-of-the art microscopy and other biochemical tools to define the pathogenesis of M. tuberculosis and HIV. Additionally, we aim to apply novel strategies such as the use of single-domain antibodies/nanobodies not only to unravel the intricate relationships of these pathogens with the host, but also to use as diagnostic and therapeutics tools.

Two cell images, side by side. — Left: Visualizing the different steps of phagocytosis. Macrophages were incubated with zymosan (β-glucan-containing fungal particulate; red color), and their ability of binding the particulates was examined by confocal microscopy. Cells were fixed and stained with phalloidin (green) to visualize the outline of the cells. DAPI (blue) was used to stain the nuclei. Right: Phagocytosis of M. tuberculosis by macrophages.

Top, Phagocytosis: Phagocytic cup formation in wild type cells.
A movie showing live confocal microscopy imaging of the formation of a phagocytic cup upon binding of C. albicans (shown in red) in control DC2.4 cells that stably express LifeAct (shown in green).

Citation: Tafesse FG, Rashidfarrokhi A, Schmidt FI, Freinkman E, Dougan S, Dougan M, et al. (2015) Disruption of Sphingolipid Biosynthesis Blocks Phagocytosis of Candida albicans. PLoS Pathog 11(10): e1005188. doi:10.1371/journal.ppat.1005188

Bottom, Phagocytosis: Phagocytic cup formation in cells that are devoid of sphingolipids.
A movie showing live confocal microscopy imaging of the formation of a phagocytic cup upon binding of C. albicans (shown in red) in SPT2-deficient DC2.4 cells that stably express LifeAct (shown in green).