The Human Innate Immune Protein Calprotectin Elicits a Multi-Metal Starvation Response in Pseudomonas Aeruginosa

The study investigated the effects of the innate immune protein calprotectin (CP) on the opportunistic pathogen Pseudomonas aeruginosa, focusing on how CP induces a multi-metal starvation response. CP was found to sequester essential metals like iron (Fe), zinc (Zn), and manganese (Mn), which are critical for pathogen growth. The research revealed that CP triggers an incomplete Fe-starvation response but a more complete Zn-starvation response, leading to increased expression of Zn transporters and Zn-independent proteins. Additionally, CP treatment resulted in the expression of membrane-modifying proteins, enhancing resistance to polymyxin B. This study highlighted that the response to CP involves both single and multi-metal starvation responses, affecting factors related to the pathogen's virulence potential and broadening the understanding of its interaction with the host.