Abstract

How can a bacterium inhabit a eukaryotic cell without triggering its destruction—or being destroyed itself? This is the central question explored by the Salje lab.

Our research focuses on Orientia tsutsugamushi, an obligate intracellular bacterium that lives within the cytoplasm of eukaryotic host cells. This unique niche places the bacterium in close proximity to organelles and host cell processes, offering both opportunities and threats. While the cytoplasm provides access to essential nutrients, it also exposes Orientia to cell-autonomous immune defenses evolved to eliminate such invaders. We use O. tsutsugamushi as a model to uncover how bacteria adapt to and exploit this challenging intracellular environment. Our work sheds light on the strategies used to evade host immunity and establish stable, long-term interactions with eukaryotic cells. At its broadest, this work offers insight into the evolutionary origins of eukaryotic life itself—echoing the ancient symbioses that gave rise to mitochondria and chloroplasts. In this Biochemistry Friday seminar, members of the Salje lab will present a broad overview of our ongoing research, highlighting how one bacterium has evolved to live in remarkable intimacy with its eukaryotic host.