We are primarily interested in finding out how Legionella protects itself from degradation by protozoa and by human macrophages. When Legionella are eaten by amoebae or macrophages, they prevent fusion of the phagosome containing the bacteria with lysosomes. Then, the bacteria alter the vacuole so that it is a good place for the bacteria to grow. We study the Legionella proteins that directly affect these alterations in organelle behavior in the host cells. We take advantage of bacterial genetics and genomics to learn more about these important bacterial proteins and the host proteins with which they interact. We benefit from collaborations that study the genetics and cell biology of a model host, Dictyostelium discoideum, a soil amoeba.

Combined phase and fluorescence image of Legionella pneumophila expressing green fluorescent protein (gfp) replicating within the soil amoeba Dictyostelium discoideum. Note the four replicative compartments, each containing many bacteria.