Abstract
Penicillium marneffei is a significant opportunistic fungal pathogen in Southeast Asia and its ability to survive inside the host macrophages is believed to be important in the establishment of infection. Previously, we isolated a gene encoding a catalase- peroxidase (cpeA) from P. marneffei and showed that the cpeA transcript is specifically upregulated during yeast phase growth at 37°C. In this study, the cpeA transcript was found to be induced during the mycelium to yeast phase transition and during stress conditions induced by hydrogen peroxide treatment. Null mutation of cpeA reduced the fungal tolerance to hydrogen peroxide but not to heat stress. These results indicated that the CpeA plays a crucial role in this fungus’ oxidative stress response. Western blot analysis demonstrated that the CpeA induced antibody production in P. marneffei-infected patients, including highly exposed-healthy people. This is the first report that the catalase-peroxidase possesses an immunogenic property in fungi.
Acknowledgments
Thank you to the National Research University Project under Thailand's Office of the Higher Education Commission and the Faculty of Medicine Endowment fund for Medical Research, Chiang Mai University, Thailand, for their financial support.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and the writing of the paper.
This paper was first published online on Early Online on 16 July 2013.