T cell response in Aggregatibacter actinomycetemcomitans-associated periodontal disease - Project Summary/Abstract Periodontitis (PD) is one of the most common inflammatory diseases, affects hundreds of millions of people worldwide, and poses a significant global economic burden. Severe PD leads to oral mucosal inflammation, destruction of tooth-supporting bone and tooth loss. Aggregatibacter actinomycetemcomitans (Aa) is an oral microbe that is associated with severe disease, yet, how T cell recognition and the ensuing immune response to Aa contributes to immunopathology is not well understood. Thus, this proposal will explore the central hypothesis that Aa-specific T cell responses contribute to tissue destruction in Aa-associated periodontitis. In Aim 1, systemic T cell response to Aa in human PD will be assessed. Biobanked patient peripheral blood mononuclear cells (PBMC) will be co-cultured with heat-killed Aa. T cells will be isolated and assessed by flow cytometry and single cell RNA sequencing. In Aim 2, the role of Aa-specific T cells in periodontal immunopathology will be determined. T cells that respond to Aa antigen will be used to generate retrogenic T cell receptor (rgTCR) mice that produce T cells specific to Aa antigen. Aa-specific T cells will be transferred to mice followed by induction of Aa-associated experimental periodontitis. Immune response and pathology will be assessed using bone loss measurement, iterative immunostaining, flow cytometry, and single cell RNA sequencing. Successful completion of these aims will begin to uncover the role of adaptive immune response in oral disease and may pave the way for precise therapeutic interventions for PD. The proposed experiments will provide me with training in new methodologies (human and mouse T cell culture, iterative immunostaining, adoptive cell transfer) and concepts (host-microbe interactions, T cell biology), which will serve as a critical foundation to my independent research program that will study T cell response to indigenous and pathogenic microbes at the oral barrier in mice and humans. The mentored phase will occur in the laboratories of my primary mentor and co-mentor, Dr.’s Moutsopoulos and Belkaid at NIH, which have the combined expertise, equipment and facilities necessary to carry out the proposed work. Additional scientific, career, and technical support will be provided by a well-rounded team of mentor-advisors and consultants. I will meet regularly with my team to receive feedback on research and career progress. I will also complete additional training in grant/manuscript writing, lab management, mentorship, and academic job market preparation. The proposed training plan will provide necessary skills to establish and lead a competitive independent research program.
