The Training Program in Host-Pathogen Interactions (HPI) has supported four (4) predoctoral students per year in the areas of microbial pathogenesis and host defense for the past 9 years. This renewal application seeks to continue our success at this same level and will build upon the many strengths that have been developed at UMCP over these first two funding periods. Our now 29 training faculty are remarkably interactive, allowing our trainees to be exposed to a variety of diverse research techniques and approaches. Multi-disciplinary methodologies to pathogen research will be emphasized to take advantage of our widespread expertise in diverse research areas including biomaterials and nanosciences, computational biology and genomics, microbiology and immunology, and microbial pathogenesis. Trainees in the HPI program will be exposed to a variety of career alternatives, and attend panels and workshops from previous trainees and other professionals who have positions in academia, government, biotech, scientific review, intellectual property, science writing, and entrepreneurship. The didactic component of this training program is organized through the Biological Sciences Training Program (BISI) and the research program is guided by a highly qualified team including the Training Program Co- Directors, an Internal Steering Committee, and an Outside Advisory Committee comprised of experts in bacterial pathogenesis, host defense and T32 administration. Predoctoral students are selected for this program from a large and increasingly qualified applicant pool. Of the 18 trainees supported by the HPI Training Program over the last 5 years, two (2) are from underrepresented populations (11%), and 9/18 trainees (50%) were women. Outcomes of these trainees have been outstanding, with an average of 4 papers per trainee. For the 7 who defended their PhD, the average is 5 papers each and all are now in postdoctoral fellowships (6) or research education (1). Of the 29 faculty trainers, 2 are from underrepresented populations (7%) and 6 are women (21%). This HPI training program takes advantage of the close proximity of UMCP to the NIH, FDA, WRAIR, and the Department of Homeland Security and we have sent students into laboratories from all of these institutions to learn techniques. Finally, our trainees present their research at local, national, and international meetings. Thus, the Training Program in Host- Pathogen Interactions plays a key role in the continued development of HPI at the University of Maryland, College Park.