Maintenance of immune homeostasis is crucial for survival. In addition to providing effective clearance of pathogens, a carefully balanced immune system must also limit autoimmunity by preventing responses against self-antigens. The recent characterization of T-regulatory (Treg) cells has revealed a major regulatory pathway that is utilized to prevent inappropriate activation of the immune system and maintain homeostasis. T-regulatory cells arise either during thymic development (tTregs), or are generated in the periphery from effector cells exposed to particular cytokine milieu (induced T-regs or iTregs). It is now well established that al Tregs are characterized by the expression of the transcription factor Foxp3, which orchestrates the production of genes that help mediate the effector functions of these cells. Recent work in our laboratory has revealed that the protein kinase PDK1 and the transcription factor NF-?B play a critical role in Treg development and function. In extensive preliminary studies we have now demonstrated a clear involvement of NF-?B as a critical regulator of Treg function. However, exactly how NF-?B influences Treg function remains unclear. In this grant application we will investigate the role of NF-?B in Tregs beyond its role i regulating the expression of Foxp3. In the first aim we will determine whether NF-?B plays a role in Treg differentiation subsequent to FoxP3 expression by deleting NF-?B inducibly. In the second aim, we will characterize the genetic program in Tregs that is controlled by NF-?B. Finally, in the third aim, we will determine which signaling pathway is responsible for activating NF-?B in Tregs, and explore the role of PKC? in this process.

Public Health Relevance

T-regulatory cells (Treg) have emerged as key modulators of the immune system and help prevent the development of autoimmune and inflammatory diseases. Studies from our laboratory have revealed that NF-?B plays a critical role in Treg development and function;however, the mechanism by which NF-?B functions in these cells remains to be fully explained. In this application we are proposing to understand how NF-?B contributes to the function of Tregs! ! !

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI068977-08
Application #
8599742
Study Section
Cellular and Molecular Immunology - B Study Section (CMIB)
Program Officer
Lapham, Cheryl K
Project Start
2006-02-01
Project End
2017-12-31
Budget Start
2014-01-01
Budget End
2014-12-31
Support Year
8
Fiscal Year
2014
Total Cost
$360,000
Indirect Cost
$135,000
Name
Columbia University (N.Y.)
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
621889815
City
New York
State
NY
Country
United States
Zip Code
10032
Grinberg-Bleyer, Yenkel; Caron, Rachel; Seeley, John J et al. (2018) The Alternative NF-?B Pathway in Regulatory T Cell Homeostasis and Suppressive Function. J Immunol 200:2362-2371
Oh, Hyunju; Grinberg-Bleyer, Yenkel; Liao, Will et al. (2017) An NF-?B Transcription-Factor-Dependent Lineage-Specific Transcriptional Program Promotes Regulatory T Cell Identity and Function. Immunity 47:450-465.e5
Grinberg-Bleyer, Yenkel; Oh, Hyunju; Desrichard, Alexis et al. (2017) NF-?B c-Rel Is Crucial for the Regulatory T Cell Immune Checkpoint in Cancer. Cell 170:1096-1108.e13
Postler, Thomas S; Pantry, Shara N; Desrosiers, Ronald C et al. (2017) Identification and characterization of a long non-coding RNA up-regulated during HIV-1 infection. Virology 511:30-39
Dainichi, Teruki; Hayden, Matthew S; Park, Sung-Gyoo et al. (2016) PDK1 Is a Regulator of Epidermal Differentiation that Activates and Organizes Asymmetric Cell Division. Cell Rep 15:1615-23
Yu, Minjun; Owens, David M; Ghosh, Sankar et al. (2015) Conditional PDK1 Ablation Promotes Epidermal and T-Cell-Mediated Dysfunctions Leading to Inflammatory Skin Disease. J Invest Dermatol 135:2688-2696
Grinberg-Bleyer, Yenkel; Dainichi, Teruki; Oh, Hyunju et al. (2015) Cutting edge: NF-?B p65 and c-Rel control epidermal development and immune homeostasis in the skin. J Immunol 194:2472-6
Hayden, Matthew S; Ghosh, Sankar (2014) Regulation of NF-?B by TNF family cytokines. Semin Immunol 26:253-66
Kang, Jung-Ah; Jeong, Sang Phil; Park, Daeho et al. (2013) Transition from heterotypic to homotypic PDK1 homodimerization is essential for TCR-mediated NF-?B activation. J Immunol 190:4508-15
Park, Sung-Gyoo; Long, Meixiao; Kang, Jung-Ah et al. (2013) The kinase PDK1 is essential for B-cell receptor mediated survival signaling. PLoS One 8:e55378

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