Impact of Calprotectin on Bacterial Physiology

Ongoing collaborative studies with Dr. Elizabeth Nolan’s laboratory at MIT have examined the impact of calprotectin (CP) on P. aeruginosa iron homeostasis. Originally identified as the “CF antigen” due to its abundance in the lungs of CF patients, CP makes up >40% of the soluble protein in circulating neutrophils. When released from neutrophils, CP binds to several divalent transition metal ions, including zinc, manganese, and nickel to hinder microbial growth. In 2016, the Nolan laboratory made the landmark discovery that CP also bound to the reduced, ferrous form of iron. Subsequent work in collaboration with our laboratory demonstrated that CP induces a robust iron starvation response in P. aeruginosa. Collaborative work in the Nolan and Oglesby laboratories aims to determine how CP-dependent sequestration of multiple metal ions, including iron, affects the physiology and virulence trait expression by P. aeruginosa.