Summary (Overall, Sil and Dandekar) The overarching theme of the proposed Coccidioides Collaborative Research Center (CCRC) is to identify molecules and pathways at the Coccidioides host-pathogen interface. Our long-term goal is to analyze the dialog between fungus and the host immune system in the context of models (macrophages and mice) and in the context of chronic and disseminated infections (in humans). Our expertise with basic mycology will facilitate our determination of Coccidioides factors that are critical for causing disease. Our rich source of clinical samples from the endemic region of California and our access to technological innovation will facilitate our ability to identify molecules, cells, metabolites, and pathways that correlate with a patient context that is permissive or restrictive for dissemination. Our expertise with data analysis will promote the integration of our molecular findings to generate an understanding of host response pathways that are correlated with disease state and clinical outcome. Additionally, we will evaluate the diagnostic potential of Coccidioides antigens and host biomarkers, thereby closing existing gaps in the diagnosis of coccidioidomycosis. At the same time, we will make key basic discoveries in microbial biology and host response, driving the field of fungal pathogenesis and medical mycology forward. Finally, by integrating the data from Projects and Cores, we hope to identify new molecular targets for anti-fungal development as well as host pathways that could be targeted by novel or existing biologics to tip the immune response in favor of the host.