Toll-like receptor (TLR) signaling plays a crucial role in mediating innate immunity and, when deregulated, also contributes to the pathogenesis of inflammatory diseases. Better understanding of the molecular mechanisms regulating TLR signaling and inflammatory responses is highly significant for improving the therapeutic approaches in the treatment of inflammatory diseases. During the previous funding cycles, the PI?s laboratory has made seminal discoveries in this area. Moreover, we have generated a large body of innovative preliminary data that form a solid foundation for this continuation application. In particular, our preliminary studies demonstrated a crucial role for the protein kinase, TBK1, in controlling TLR signaling and preventing inflammatory disorders. Although TBK1 is known as a kinase that mediates type I interferon (IFN) induction and antiviral innate immunity, its in vivo functions have been poorly studied due to the lack of a viable mouse model. Using newly generated TBK1 conditional knockout (cKO) mice, we have discovered novel functions of TBK1 in the regulation of immune and inflammatory responses. Our preliminary studies have demonstrated a crucial role for TBK1 in controlling inflammatory responses by functioning in both innate immune cells and intestinal epithelial cells (IECs). Myeloid cell-conditional TBK1 KO (Tbk1-MKO) mice are hypersensitive to colitis induction and spontaneously develop aberrant adipose tissue expansion and inflammation. TBK1 negatively regulates TLR signaling and TLR-stimulated expression of proinflammatory cytokines in macrophages. We have further demonstrated that conditional deletion of TBK1 in IECs increases proinflammatory cytokine production and Th17 cell generation in the intestine, sensitizing mice for intestinal tumorigenesis. Based on these innovative findings, we hypothesize that TBK1 functions in both innate immune cells and IECs to regulate proinflammatory TLR signaling and inflammatory disorders. The overall objective of this continuation application is to elucidate the mechanism underlying the anti-inflammatory functions of TBK1. To accomplish this overall objective, we will perform two specific aims.
In Aim 1, we will examine how myeloid cell TBK1 regulates TLR signaling and inflammation.
In Aim 2, we will elucidate the mechanism by which TBK1 functions in IECs to regulate intestinal immune homeostasis and tumorigenesis. We believe that these proposed studies address novel mechanisms that regulate TLR signaling and inflammatory responses and will lead to high-impact results that substantially advance the field.

Public Health Relevance

Toll-like receptor (TLR) signaling mediates host defense against infections, but deregulated TLR signaling is linked to inflammatory diseases. The proposed project addresses innovative questions regarding the mechanism underlying TLR signaling and inflammation and will lead to high-impact findings with therapeutic implications.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
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Innate Immunity and Inflammation Study Section (III)
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Vazquez-Maldonado, Nancy
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University of Texas MD Anderson Cancer Center
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Shi, Jian-Hong; Sun, Shao-Cong (2018) Tumor Necrosis Factor Receptor-Associated Factor Regulation of Nuclear Factor ?B and Mitogen-Activated Protein Kinase Pathways. Front Immunol 9:1849
Shi, Jian-Hong; Xie, Xiaoping; Sun, Shao-Cong (2018) TBK1 as a regulator of autoimmunity and antitumor immunity. Cell Mol Immunol 15:743-745
Zhu, Lele; Xie, Xiaoping; Zhang, Lingyun et al. (2018) TBK-binding protein 1 regulates IL-15-induced autophagy and NKT cell survival. Nat Commun 9:2812
Jie, Zuliang; Yang, Jin-Young; Gu, Meidi et al. (2018) NIK signaling axis regulates dendritic cell function in intestinal immunity and homeostasis. Nat Immunol 19:1224-1235
Yang, Jie; Zhang, Siya; Zhang, Lingyun et al. (2018) Lymphatic endothelial cells regulate B-cell homing to lymph nodes via a NIK-dependent mechanism. Cell Mol Immunol :
Zhang, Huiyuan; Li, Haiyan S; Hillmer, Emily J et al. (2018) Genetic rescue of lineage-balanced blood cell production reveals a crucial role for STAT3 antiinflammatory activity in hematopoiesis. Proc Natl Acad Sci U S A 115:E2311-E2319
Sun, Shao-Cong (2017) The non-canonical NF-?B pathway in immunity and inflammation. Nat Rev Immunol 17:545-558
Liu, Ting; Zhang, Lingyun; Joo, Donghyun et al. (2017) NF-?B signaling in inflammation. Signal Transduct Target Ther 2:
Hu, Hongbo; Wang, Hui; Xiao, Yichuan et al. (2016) Otud7b facilitates T cell activation and inflammatory responses by regulating Zap70 ubiquitination. J Exp Med 213:399-414
Hu, Hongbo; Sun, Shao-Cong (2016) Ubiquitin signaling in immune responses. Cell Res 26:457-83

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