The overall goals of our research group are to better understand host/pathogen interactions in intestinal cells, to define the unique physiology of the epithelial cell response to infection, and to determine how this relates to the maintenance of proteostasis. In particular we study infection and response to microsporidia, which comprise a phylum of fungal-like obligate pathogens that can infect almost all animal hosts. The major focus is on the response to Nematocida microsporidian pathogens, which are the most common known cause of infection in the wild for the nematode C. elegans. Our recent findings highlight a key role for an intrinsic defense pathway called the “Intracellular Pathogen Response” or IPR, which provides resistance against natural microsporidian infections as well as natural viral infections. The IPR also regulates proteostasis. We hypothesize that the IPR uses species-specific ubiquitin ligases that target non-self and misfolded proteins for destruction.