Suzan Rooijakkers studies how the human immune system kills invading bacteria, with a particular focus on the complement system, a key plasma protein network that promotes bacterial clearance through phagocytosis and direct killing. Her research aims to uncover the molecular mechanisms by which complement destroys bacterial pathogens, including the action of the Membrane Attack Complex (MAC). Using innovative reductionist model systems, her team has provided new insights into complement-mediated bacterial killing and phagocytosis. These findings advance our understanding of host-pathogen interactions and may enable the development of novel antibody-based therapies, targeted antimicrobial strategies, and interventions to prevent harmful complement activation during severe bacterial infections and sepsis.