Type 1 diabetes (T1D) results from a complex cascade of events that breaks immune tolerance and culminates in the destruction of islet 2 cells. B lymphocytes (B cells) play a critical role in disease development, probably via antigen-presentation to pathogenic T cells. B cell contribution to the development of diabetes depends upon multiple factors, including loss of tolerance to self antigen. This tolerance is mediated by cellular responses to antigen-binding via the B cell receptor (BCR). Bruton's tyrosine kinase (BTK) is a central component of the BCR-triggered signaling pathway. Understanding cell signaling components underlying B cell-driven diabetes development will advance the field toward specific targeting of pathogenic B cells. We have introgressed btk-deficiency onto the nonobese diabetic (NOD) mouse model of T1D, and found that this results in significant protection against the development of diabetes. In addition, btk-deficiency interferes with B cell related breaches of immune tolerance, as evidenced by the loss of insulin-specific IgG autoantibodies in wild type NOD mice, and reduction of insulin-binding B cells in a transgenic anti-insulin BCR model. The specific hypothesis underlying this proposal is that BTK-mediated propagation of BCR signals contributes to 1) selection and survival of autoreactive B lymphocytes, and 2) disease- promoting functional properties of these B cells. To understand the mechanisms of action of BTK in breaking B lymphocyte tolerance and promoting disease in autoimmune diabetes, we propose to: 1) discover how BTK participates in the selection and retention of autoreactive B lymphocytes, using use new tools that include a conditional, B cell-specific BTK knockout model and small molecule BTK- inhibitors, 2) determine which domains of the BTK molecule are responsible for autoreactive B lymphocyte selection and function, by systematically restoring independent components responsible for the kinase and linking functions, and 3) investigate the mechanisms of btk-deficiency in preventing T1D by examining effects on B cell subsets, antigen-presenting outcomes, and regulatory parameters. This project has direct clinical importance in understanding how BCR-signaling supports the selection, survival and function of autoreactive B cells in T1D, as a necessary step in developing therapeutic interventions.
Autoreactive B lymphocytes are essential to the development of type 1 diabetes. The goal of this project is to understand how B cell signaling, mediated by Bruton's tyrosine kinase, supports the breach of immunologic tolerance that occurs in this disease. These discoveries will provide new avenues of intervention for the specific targeting of autoreactive, pathogenic B cells.
|Bahnan, Wael; Boucher, Justin C; Gayle, Petoria et al. (2018) The eIF2? Kinase Heme-Regulated Inhibitor Protects the Host from Infection by Regulating Intracellular Pathogen Trafficking. Infect Immun 86:|
|Nyhoff, Lindsay E; Clark, Emily S; Barron, Bridgette L et al. (2018) Bruton's Tyrosine Kinase Is Not Essential for B Cell Survival beyond Early Developmental Stages. J Immunol 200:2352-2361|
|Wilfong, Erin M; Lentz, Robert J; Guttentag, Adam et al. (2018) Interstitial Pneumonia With Autoimmune Features: An Emerging Challenge at the Intersection of Rheumatology and Pulmonology. Arthritis Rheumatol 70:1901-1913|
|Nyhoff, Lindsay E; Crofford, Leslie J; Kendall, Peggy L (2017) Reply. Arthritis Rheumatol 69:475-477|
|Nyhoff, Lindsay E; Barron, Bridgette L; Johnson, Elizabeth M et al. (2016) Bruton's Tyrosine Kinase Deficiency Inhibits Autoimmune Arthritis in Mice but Fails to Block Immune Complex-Mediated Inflammatory Arthritis. Arthritis Rheumatol 68:1856-68|
|Kendall, Peggy L (2016) New Players in the Field of T1D: Anti-Peripherin B Lymphocytes. Diabetes 65:1794-6|
|Crofford, Leslie J; Nyhoff, Lindsay E; Sheehan, Jonathan H et al. (2016) The role of Bruton's tyrosine kinase in autoimmunity and implications for therapy. Expert Rev Clin Immunol 12:763-73|
|Hemler, Jonathan A; Phillips, Elizabeth J; Mallal, Simon A et al. (2015) The evolving story of human leukocyte antigen and the immunogenetics of peanut allergy. Ann Allergy Asthma Immunol 115:471-6|
|Case, James B; Bonami, Rachel H; Nyhoff, Lindsay E et al. (2015) Bruton's Tyrosine Kinase Synergizes with Notch2 To Govern Marginal Zone B Cells in Nonobese Diabetic Mice. J Immunol 195:61-70|
|Bonami, Rachel H; Wolfle, William T; Thomas, James W et al. (2014) NFATc2 (NFAT1) assists BCR-mediated anergy in anti-insulin B cells. Mol Immunol 62:321-8|
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