Phagocytosis generates intracellular compartments—phagosomes—that serve as central hubs for innate immune sensing of potentially harmful microbes, dying cells, cellular debris, and foreign particles. These organelles are enriched with receptors, enzymes, and signaling molecules that assess the nature of the internalized cargo and coordinate appropriate immune responses.

Despite the phagosome’s critical role in immune surveillance, the protein composition of phagosomes—especially those containing biologically relevant cargoes like microbes—remains poorly characterized.

Building on proximity labeling (PL) technology, we previously developed PhagoPL, a method for profiling the proteome of phagosomes containing model microorganisms. This approach enabled the discovery of novel microbe-sensing mechanisms.

One major project in our lab is to further upgrade PhagoPL into a more versatile platform for studying the proteome of diverse intracellular vesicles. 

In earlier work, we applied PhagoPL to analyze phagosomes containing avirulent gram-negative E. coli. Our ongoing efforts aim to extend this work to pathogenic intracellular bacteria, investigating how host cells interact with a broader range of virulent species.

This project will use PhagoPL to dissect host-bacteria interactions within bacteria-containing vacuoles, with the goal of identifying novel mechanisms of innate immune and bacteria virulence conteraction.

In parallel, we are also developing new approaches to study host-intrinsic responses to bacteria that escape from vacuoles into the cytosol.