Treating systemic fungal disease is a difficult task, due to the limited number of antifungal agents that can effectively eliminate fungal infections without harming the patient. This project seeks to enable the development of antifungal agents with an improved ability to selectively kill fungal cells without harming human cells. To accomplish this task, peptides will be studied as tools to target fungal cells and to carry molecules across cellular barriers and into fungal cells. This project will reveal properties of the peptides that are important for specifically targeting fungal cells over human cells and will provide information on limitations on the size of molecules that can be carried into the cells. This information could then be used to design improved antifungal agents and will also contribute to knowledge of fungal cell biology.
This project will use rational design strategies and molecular biology tools to build an understanding of the interaction of cell-penetrating peptides (CPPs) with fungal cells, specifically the fungal pathogen Candida albicans, by (1) identifying CPPs able to cross the cell wall and cell membrane of C. albicans, (2) determining cargo tethering and size limitations for CPP-mediated transport into fungal cells, and (3) engineering CPPs for improved translocation and selectivity. CPPs previously shown to enter mammalian cells will be screened for their ability to translocate into fungal cells, and limitations on the size of cargo and how the cargo is tethered to CPPs will be studied using genetic fusions of CPPs to protein cargo. To improve the translocation and selectivity of CPPs, peptides will be designed with varied hydrophobicity and net charge, and the translocation into both C. albicans and mammalian cells will be assayed to determine a set of rules for designing CPPs for high levels of translocation into fungal cells and low levels of translocation into mammalian cells. This project will elucidate the relationship between a peptide's structure and its function as a CPP in fungal cells and provide a new platform for designing targeted antifungal agents and delivering bioactive molecules for fungal cell biology studies. This project will provide knowledge needed to design improved antifungal agents with the specificity and efficacy needed to treat systemic fungal disease, and the approaches developed in this project will be transferable to developing delivery systems for treating other diseases. In addition, this project will provide students with training for future positions in biomolecular engineering by (1) involving high school, undergraduate, and graduate students in the proposed research project, (2) creating activities for Maryland Day that introduce children and their parents to biomolecular engineering, and (3) incorporating research techniques and results into undergraduate courses. This proposal is co-funded by the Biomedical Engineering Program and by the Particulate and Multiphase Processes Program, both in the Chemical, Bioengineering, Environmental and Transport Systems Division.
