Role of a CUF1/CTR4 copper regulatory axis in the virulence of Cryptococcus neoformans

SR Waterman, M Hacham, G Hu, X Zhu… - The Journal of …, 2007 - Am Soc Clin Investig
SR Waterman, M Hacham, G Hu, X Zhu, YD Park, S Shin, J Panepinto, T Valyi-Nagy
The Journal of clinical investigation, 2007Am Soc Clin Investig
The study of regulatory networks in human pathogens such as Cryptococcus neoformans
provides insights into host-pathogen interactions that may allow for correlation of gene
expression patterns with clinical outcomes. In the present study, deletion of the cryptococcal
copper-dependent transcription factor 1 (Cuf1) led to defects in growth and virulence factor
expression in low copper conditions. In mouse models, cuf1 Δ strains exhibited reduced
dissemination to the brain, but no change in lung growth, suggesting copper is limiting in …
The study of regulatory networks in human pathogens such as Cryptococcus neoformans provides insights into host-pathogen interactions that may allow for correlation of gene expression patterns with clinical outcomes. In the present study, deletion of the cryptococcal copper-dependent transcription factor 1 (Cuf1) led to defects in growth and virulence factor expression in low copper conditions. In mouse models, cuf1Δ strains exhibited reduced dissemination to the brain, but no change in lung growth, suggesting copper is limiting in neurologic infections. To examine this further, a biologic probe of available copper was constructed using the cryptococcal CUF1-dependent copper transporter, CTR4. Fungal cells demonstrated high CTR4 expression levels after phagocytosis by macrophage-like J774.16 cells and during infection of mouse brains, but not lungs, consistent with limited copper availability during neurologic infection. This was extended to human brain infections by demonstrating CTR4 expression during C. neoformans infection of an AIDS patient. Moreover, high CTR4 expression by cryptococcal strains from 24 solid organ transplant patients was associated with dissemination to the CNS. Our results suggest that copper acquisition plays a central role in fungal pathogenesis during neurologic infection and that measurement of stable traits such as CTR4 expression may be useful for risk stratification of individuals with cryptococcosis.
The Journal of Clinical Investigation