The adaptive immune system serves to eliminate pathogens while sparing host tissue. The efficiency of this system is largely dependent on balance; unrestrained immunity can cause autoimmunity while a slow or absent response can lead to chronic infection and cancer. Regulatory T cells (Tregs) play a critical role in maintainin this balance through the suppression of self-reactive immune responses. Treg stability is crucial to maintain effective suppressive capacity. Neuropilin-1 (Nrp1), a surface receptor has emerged as an important mediator of Treg stability. Nrp1 binds the ligand, Semaphorin-4a (Sema-4a), leading to enhanced Treg stability intratumorally. In the absence of Nrp1:Sema4a ligation, Tregs lose stability and suppressive capabilities, leading to enhanced anti-tumor immunity and reduced tumor growth. The fate and function of Nrp1-deficient Tregs is unclear. This research proposal suggests experiments that will propel our understanding of how Nrp1 alters Treg stability, and will elucidate the molecular mechanisms leading to a distinct Treg cell population and reduced tumor growth. Understanding these mechanisms is of crucial importance in understanding tumor immunology, and in creating new targets for immunotherapy.

Public Health Relevance

Regulatory T cells are essential for providing balance to the immune system. These cells provide protection against autoimmune diseases; however, they also prevent successful anti-cancer immunity. Our research seeks to understand how regulatory T cells are stabilized in the tumor microenvironment, and how the lack of stability affects the fat and function of regulatory T cells in cancer.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
1F31CA189441-01A1
Application #
8903896
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Schmidt, Michael K
Project Start
2015-04-01
Project End
2017-08-30
Budget Start
2015-04-01
Budget End
2016-03-31
Support Year
1
Fiscal Year
2015
Total Cost
Indirect Cost
Name
University of Pittsburgh
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Overacre-Delgoffe, Abigail E; Chikina, Maria; Dadey, Rebekah E et al. (2017) Interferon-? Drives Treg Fragility to Promote Anti-tumor Immunity. Cell 169:1130-1141.e11
Overacre, Abigail E; Vignali, Dario Aa (2016) T(reg) stability: to be or not to be. Curr Opin Immunol 39:39-43