Inhibitory forms of killer cell Ig-like receptors (KIR) are important negative regulators of human natural killer (NK) cell activation. They maintain NK cell tolerance through recognition of MHC class I molecules (HLA-A, -B, and -C) on the surface of normal cells in the body. KIR transduces inhibitory signals through the recruitment of SHP-1 and SHP-2 tyrosine phosphatases. Since NK cell activation is controlled by a balance between activating and inhibitory receptors, the surface expression level of KIR is a key determinant of the NK cell activation potential. While a great deal of effort has been directed toward understanding the mechanism by which KIR transduces inhibitory signals, very little is known about the post-translational mechanisms regulating surface expression, endocytosis, and plasma membrane trafficking of these receptors. Improved understanding of the mechanisms regulating KIR surface trafficking and expression could provide novel therapeutic targets to promote NK cell activation toward tumors and virus infected cells by reducing the surface expression levels of KIR. We will define the molecular mechanisms regulating inhibitory KIR trafficking by addressing the following specific aims.
Aim 1 will assess the role of ligand in regulating surface expression of inhibitory KIR. Here we will test the hypothesis that ligand engagement impacts upon the membrane trafficking of inhibitory KIR.
Aim 2 will elucidate the molecular mechanisms mediating endocytosis and degradation of inhibitory KIR. We hypothesize that certain molecular interactions control these pathways, and our experiments will test their impacts on surface receptor expression.
Aim 3 will examine the role of the b arrestin 2 adaptor protein on surface trafficking of inhibitory KIR. We hypothesize that this adaptor promotes surface expression of KIR and stabilizes interaction of the receptor with SHP-1 and SHP-2 phosphatases.

Public Health Relevance

Natural killer (NK) cells can attack tumors and virus-infected cells, and their activation state is controlled by a balance of signals from activating and inhibitory receptors. Inhibitory killer cell Ig-like receptors (KIR) are key regulators on human NK cells that establish tolerance toward normal cells of the body, but surprisingly little is known about the mechanisms that maintain their surface expression. The studies proposed in this application will characterize the molecular regulation of KIR membrane trafficking to develop strategies for reducing their surface expression and thereby potentiating NK cell responses toward tumors and viruses.

Agency
National Institute of Health (NIH)
Type
Research Project (R01)
Project #
5R01CA083859-13
Application #
8606416
Study Section
Innate Immunity and Inflammation (III)
Program Officer
Howcroft, Thomas K
Project Start
Project End
Budget Start
Budget End
Support Year
13
Fiscal Year
2014
Total Cost
Indirect Cost
City
Philadelphia
State
PA
Country
United States
Zip Code
19111
Davis, Zachary B; Cogswell, Andrew; Scott, Hamish et al. (2016) A Conserved HIV-1-Derived Peptide Presented by HLA-E Renders Infected T-cells Highly Susceptible to Attack by NKG2A/CD94-Bearing Natural Killer Cells. PLoS Pathog 12:e1005421
Steblyanko, Maria; Anikeeva, Nadia; Campbell, Kerry S et al. (2015) Integrins Influence the Size and Dynamics of Signaling Microclusters in a Pyk2-dependent Manner. J Biol Chem 290:11833-42
Brusilovsky, Michael; Radinsky, Olga; Cohen, Limor et al. (2015) Regulation of natural cytotoxicity receptors by heparan sulfate proteoglycans in -cis: A lesson from NKp44. Eur J Immunol 45:1180-91
Anikeeva, Nadia; Steblyanko, Maria; Fayngerts, Svetlana et al. (2014) Integrin receptors on tumor cells facilitate NK cell-mediated antibody-dependent cytotoxicity. Eur J Immunol 44:2331-9
Purdy, Amanda K; Alvarez Arias, Diana A; Oshinsky, Jennifer et al. (2014) The ap-2 clathrin adaptor mediates endocytosis of an inhibitory killer cell Ig-like receptor in human NK cells. J Immunol 193:4675-83
Campbell, Kerry S; Hasegawa, Jun (2013) Natural killer cell biology: an update and future directions. J Allergy Clin Immunol 132:536-44
Brusilovsky, Michael; Cordoba, Moti; Rosental, Benyamin et al. (2013) Genome-wide siRNA screen reveals a new cellular partner of NK cell receptor KIR2DL4: heparan sulfate directly modulates KIR2DL4-mediated responses. J Immunol 191:5256-67
Mentlik James, Ashley; Cohen, Adam D; Campbell, Kerry S (2013) Combination immune therapies to enhance anti-tumor responses by NK cells. Front Immunol 4:481
Rosental, Benyamin; Hadad, Uzi; Brusilovsky, Michael et al. (2012) A novel mechanism for cancer cells to evade immune attack by NK cells: The interaction between NKp44 and proliferating cell nuclear antigen. Oncoimmunology 1:572-574
Grier, Jennifer T; Forbes, Lisa R; Monaco-Shawver, Linda et al. (2012) Human immunodeficiency-causing mutation defines CD16 in spontaneous NK cell cytotoxicity. J Clin Invest 122:3769-80

Showing the most recent 10 out of 33 publications