PROJECT SUMMARY/ABSTRACT Today's reality includes threats from emergent microbial diseases, rising opportunistic infections, development of multi-drug resistant microbes, and inefficacy of existing vaccines due to microbial evolution. These threats to human health necessitate comprehensive interdisciplinary training programs for the next generation of scientists in studies of the microbe-host interface and emerging methodologies. The hub for this training program will be The Ohio State University Infectious Disease Institute (IDI), which is focused on Host-Pathogen Research, Education, and Outreach. IDI brings together a vibrant and dynamic community that fosters a collaborative approach to address critical problems in infectious disease. All the preceptors for the training program are members of IDI and represent a vast array of expertise in host-pathogen interactions. Both PDs (MPD mechanism) have strong research programs and careers dedicated to training and education. Thus the PDs represent an outstanding, established and collaborative team to oversee this broad innovative program which emphasizes: 1) a highly interactive scientific community, 2) a multidisciplinary approach to science, 3) immersion of trainees in the biomedical research community of a large academic health sciences center, 4) integration of the clinical and basic sciences, 5) exposure to experienced and talented scientist educators and mentors, and 6) several added advantages to trainees, including a vibrant externship program. The major thematic areas are 1) Viral pathogens, 2) Host defense, and 3) Microbial communities. These thematic areas represent three of five IDI interdisciplinary programmatic areas and we have selected the most dedicated members from each area to serve as preceptors for this T32. The program will include a Selection and Oversight Committee, an outstanding and engaged External Advisory Committee, the necessary administrative structure within IDI to execute the program, and a high-quality trainee pool. Emphasis is placed on the recruitment of diversity in trainees and on formal instruction for the responsible conduct of research. We request 3 pre-doctoral, and 2 post-doctoral scholar slots per year. The proposed training experience includes a state-of-the-art curriculum, dedicated faculty, exceptional resources, exposure to diverse career paths, and mentors and networking combined with sustained institutional support that will prepare the trainees for the evolving landscape of our biomedical workforce