PROJECT SUMMARY This is an administrative supplement application that aims to promote the research productivity and career training of a promising minority pre-doctoral fellow. The hypothesis was built on a new observation made by the candidate in terms of how Paneth cell lysozyme secretion may be regulated. The proposed experiments will biochemically quantify lysozyme secretion from mouse intestinal lumen of mice lacking Rab11b trafficking. Additional proposed experiments will uncover Paneth cell specific Rab11b interactome, which may shed lights on novel regulatory mechanism for antimicrobial peptide secretion. The project will enhance and expand the overarching goal of the parent award that investigates contribution of intestinal lysozyme to mucosal immune response to commensal microbiota. The candidate is currently a full-time predoctoral fellow in the PI’s laboratory at Rutgers University. The candidate’s academic path in the last ten years convincingly demonstrated a strong motivation and persistent endeavor in pursuing laboratory research and biomedical science as a career. The project is important as elevated levels of intestinal lysozyme and its ectopic production by colonic mucosa are observed in clinically active intestinal inflammation conditions. A better understanding of how lysozyme secretion is regulated will bring insights into the frequently observed defective lysozyme packaging and secretion in Paneth cells of Crohn’s disease (CD) patients. The project is multidisciplinary in nature and relies on different expertise in experimental colitis, mucosal immunology, gnotobiotics study, genetics, and intestinal epithelial biology. Thus, the project is ideal for training of a Ph.D. candidate as it requires strong collaborative activities and scientific communication skills. Career development and mentoring plans are cohesively put in place to facilitate a successful completion of the Ph.D. dissertation and a transition into postdoctoral research by the candidate.