Regulation of lupus pathogenesis through modulation of thymic development of pathobiont-specific T cells

PROJECT SUMMARY/ABSTRACT CANDIDATE: I am a postdoctoral research associate in the laboratory of Dr. Gretchen E. Diehl in the Immunology Program at Memorial Sloan-Kettering Cancer Center. I obtained my PhD working in gut microbiota and systemic lupus erythematosus under the supervision of Dr. Martin Kriegel. My current research

applies the techniques I learned in my postdoc and graduate school to assess the role of gut microbes in the thymic development of microbiota-specific T cells and how these T cells can modulate disease in susceptible hosts. To elucidate this process, I used a tetramer-based approach to identify and track antigen-specific T cells

expansion in the thymus before they distribute and differentiate in the periphery. I plan to study how this process is altered in autoimmunity. My proposed research and mentoring plan will provide me the required foundation to transition into an independent researcher with a long-term career goal to understand how

microbiota-specific T cell responses arise and define how they exacerbate lupus pathogenesis. To achieve this goal, together with my mentoring team, I have developed a career plan that will 1) increase my technical skills, 2) refine my scientific scope, 3) improve my communication skills, and 4) expand my scientific network.

RESEARCH: Lupus development is associated with intestinal dysbiosis in patients and mouse models. Dysbiosis in lupus is characterized by pathobiont overgrowth and is linked to dysregulated immune responses that exacerbate pathogenesis. In my graduate work, I found increased pathobionts including Lactobacillus

reuteri in mouse lupus models and subsets of SLE patients. I showed L. reuteri translocated systemically, leading to increased inflammatory pathways and proinflammatory T cells which exacerbated systemic inflammation and worsened lupus pathogenesis. In my postdoctoral work, I am investigating how differentiation

of microbiota-specific T cells is regulated during development and its effects in inflammatory processes. While we and others find peripheral expansion of microbiota-specific T cells with effector function in adult mice, in young mice we surprisingly found microbiota-specific T cells first expanded in the thymus, a site not previously

known to allow for antigen-specific T cell expansion. I aim to synergize the knowledge generated during my graduate and postdoctoral training to determine if thymic development of L. reuteri-specific T cells is amplified in lupus susceptible hosts and to assess their role in lupus exacerbation. I will develop this proposal by 1)

Determining how thymic microbiota-specific T cells modulate lupus pathogenesis and 2) Defining how lupus pathobionts modulate pathobiont-specific T cells expansion. ENVIRONMENT: The laboratory is part of the Immunology program at Memorial Sloan-Kettering Cancer Center, a state-of-the-art research institute. Furthermore, my mentoring committee and collaborators will

provide the required scientific and non-scientific support for the research and career development proposed.