The goal of this proposal is to understand how pseudogymnoascus destructans causes white nose syndrome in hibernating bats

This Project Grant award from the U.S. Fish and Wildlife Service under the White-nose Syndrome National Response Implementation program (CFDA 15.684) provides $325,588.00 to the University of Wisconsin - Madison to conduct research on how the fungus Pseudogymnoascus destructans causes white-nose syndrome in hibernating bats. The research aims to identify the specific fungal proteins or "adhesins" that enable the fungus to bind to and infect bat skin cells. The findings could lead to new strategies to prevent or treat white-nose syndrome, which has devastated bat populations across North America. The project period runs from March 1, 2025 to February 28, 2027.

Pseudogymnoascus destructans initiates disease by binding to bats skin cells called a keratinocytes. Our research addresses how pseudogymnoascus destructans attaches to these cells. Our work builds upon a recent major discovery made and published by our team. We created immortal keratinocytes from a little brown BAT, which an endangered bats affected by white nose syndrome. We used the cells to discover how pseudogymnoascus destructans invades BAT skin during hibernation. As part of that research, we discovered a receptor on the surface of keratinocytes that pseudogymnoascus destructans must bind to attach to these cells, and then spread to other keratinocytes in the skin. This keratinocyte receptor is called epidermal growth factor receptor. This raises a natural question: what structure on the pseudogymnoascus destructanss surface enables IT to bind to epidermal growth factor receptor on keratincytes? Here, the so-called lock and key analogy applies epidermal growth factor receptor as the lock and pseudogymnoascus destructanss surface protein as the key, enabling the fungus to bind and then enter the cell. Such fungal structures or keys are referred to as adhesion-promoting proteins or adhesins. Our goal is to discover one or more adhesins on the surface of pseudogymnoascus destructans that enable the fungus to adhere to keratinocytes. We will use molecular biology and genetics to discover the pseudogymnoascus destructans adhesins. We have two aims: the first is to genetically express the genes from pseudogymnoascus destructans on another fungus that normally does not bind BAT keratinocytes (bakers yeast). We then experimentally test for any of the individual pseudogymnoascus destructans genes that endow bakers yeast with the new ability to bind to the keratinocytes. When we find such gene(s), we will validate that IT functions the same way in pseudogymnoascus destructans and, if so, study IT in more detail. The second aim involves careful inspection of the literature for genes from other microbes that are known to mediate attachment to their respective host cells during that infection, and then to see if such genes are present among those normally present in pseudogymnoascus destructanss own genome. We found one promising gene from another fungus that is also present in pseudogymnoascus destructanss genome. We therefore propose in the second aim to express this single gene from pseudogymnoascus destructans once again in bakers yeast to see if the yeast now can bind to keratinocytes. If we find that IT does, as above in the first aim, we will validate that IT functions the same way in pseudogymnoascus destructans and study IT in more detail. We expect that our research will identify one or more proteins from pseudogymnoascus destructans that enable the fungus to attach to keratinocytes, which is one of the earliest steps in initiating the infection. By studying the gene in more detail in pseudogymnoascus destructans, we will determine what happens to its ability to bind the cells if we genetically eliminate the gene from pseudogymnoascus destructans using molecular biology and genetic tools. This is important because, in many other microbes that cause infectious disease, genetically eliminating such adhesion-promoting genes cripples the microbes ability to bind cells and cause disease. Sometimes such adhesion-promoting proteins even make good vaccines. Alternatively, sometimes the microbes themselves that are crippled after genetically eliminating adhesin genes make good live attenuated vaccines because they cannot produce disease. We expect that our work has the high likelihood in producing such results and products, which could be used to prevent white-nose syndrome and stem the epidemic.