Candida albicans Oropharyngeal Infection Is an Exception to Iron-Based Nutritional Immunity
Norma V. Solis, Rohan S. Wakade, Scott G. Filler, Damian J. Krysan
Abstract
Nutritional immunity is a response by which infected host tissue sequesters nutrients, such as iron, to prevent the microbe from efficiently replicating. Microbial pathogens subjected to iron nutritional immunity express specific genes to compensate for low iron availability. By comparing the gene expression profiles of the common human fungal pathogen Candida albicans in 2 infection sites, we found that C. albicans infecting the kidney has the transcriptional profile of iron starvation. By contrast, the C. albicans expression profile during oropharyngeal infection indicates the fungus is not iron starved. Two transcription factors that activate the transcriptional response to iron starvation are not required for C. albicans virulence during oral infection but are required for disseminated infection of the kidney. Thus, our results indicate that C. albicans is subject to nutritional iron immunity during disseminated infection but not during oropharyngeal infection, and highlight niche specific differences in the host-Candida albicans interaction.