The Masopust laboratory studies T cell responses to viral and bacterial infections & candidate vaccines to help understand the development of immunological protection from re-infection. We employ a combination of flow cytometry, immunohistochemistry, intravital microscopy, cellular, and genetic approaches to observe and manipulate pathogen specific T cell responses. We are currently dedicated to elucidating the developmental cues that govern T cell migration to different anatomical locations, commitment to the memory lineage, and the contribution of memory T cell differentiation state and location to protection from re-infection. Memory T cells that reside within the respiratory, intestinal, and reproductive mucosa, which collectively represent the most common portals of pathogen entry or infection, are of particular interest. By understanding these issues, we hope to contribute to the development of better vaccination strategies and therapies for chronic diseases.