Natural Killer cells play a significant role in host defense, in part by attacking transformed, infected or normal cells that downregulate MHC class I molecules. Target cell recognition by NK cells involves both stimulatory and inhibitory receptors, the latter of which are specific for class I molecules. Inhibitory receptors are expressed by overlapping subsets of NK cells in a pattern that appears largely random. The loss of inhibitory signaling by MHC-specific receptors is responsible for the capacity of NK cells to attack class I-deficient cells. Because inhibitory receptors discriminate allelic variants of class I molecules, NK cells also attack MHC-different cells. Therefore, a key issue is how NK cells are rendered tolerant to self cells. The leading hypothesis, cited even in textbooks, is that each NK cell is endowed with at least one inhibitory receptor specific for a self MHC class I molecule. In the last funding period, we have developed evidence that this is not the case. A fraction of NK cells in normal mice lacks self MHC-specific receptors, yet is self-tolerant. These NK cells fail to attack class I deficient lymphoblasts or bone marrow cells. Importantly, these cells are hyporesponsive to some other defined stimuli, such as crosslinking of NKG2D or NKR-P1 stimulatory receptors. NK cells that arise in class I-deficient mice exhibit a similar hyporesponsive phenotype. Our hypothesis is that inhibitory receptor expression, being substantially stochastic during NK development, fails to endow a fraction of NK cells with self MHC-specific receptors. These NK cells achieve self-tolerance by adopting a hyporesponsive phenotype that precludes them from attacking self cells, yet allows them to function in other contexts. All the NK cells in class I-deficient mice adopt this hyporesponsive phenotype, because they fail to encounter inhibitory MHC molecules during development. To test this hypothesis and address the underlying molecular mechanisms, we propose the following specific aims:
Specific Aim 1 : To identify genes whose expression levels differ in responsive versus hyporesponsive NK cell populations.
Specific Aim 2 : To determine the signaling pathways and the steps in the pathway that are impaired in hyporesponsive NK cells.
Specific Aim 3 : To determine the relationship of NK cell hyporesponsiveness and cytokine action.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI035021-14
Application #
7204108
Study Section
Experimental Immunology Study Section (EI)
Program Officer
Miller, Lara R
Project Start
1993-12-01
Project End
2009-03-31
Budget Start
2007-04-01
Budget End
2008-03-31
Support Year
14
Fiscal Year
2007
Total Cost
$208,547
Indirect Cost
Name
University of California Berkeley
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Shifrin, Nataliya Tovbis; Kissiov, Djem U; Ardolino, Michele et al. (2016) Differential Role of Hematopoietic and Nonhematopoietic Cell Types in the Regulation of NK Cell Tolerance and Responsiveness. J Immunol 197:4127-4136
Ardolino, Michele; Hsu, Joy; Raulet, David H (2015) Cytokine treatment in cancer immunotherapy. Oncotarget 6:19346-7
Shifrin, Nataliya; Raulet, David H; Ardolino, Michele (2014) NK cell self tolerance, responsiveness and missing self recognition. Semin Immunol 26:138-44
van Bergen, Jeroen; Thompson, Allan; van Pel, Melissa et al. (2013) HLA reduces killer cell Ig-like receptor expression level and frequency in a humanized mouse model. J Immunol 190:2880-5
Xia, Mingcan; Guerra, Nadia; Sukhova, Galina K et al. (2011) Immune activation resulting from NKG2D/ligand interaction promotes atherosclerosis. Circulation 124:2933-43
Vivier, Eric; Raulet, David H; Moretta, Alessandro et al. (2011) Innate or adaptive immunity? The example of natural killer cells. Science 331:44-9
Zijlstra, Maarten; Bix, Mark; Simister, Neil E et al. (2010) Beta 2-microglobulin deficient mice lack CD4-8+ cytolytic T cells. 1990. J Immunol 184:4587-91
Joncker, Nathalie T; Shifrin, Nataliya; Delebecque, Frédéric et al. (2010) Mature natural killer cells reset their responsiveness when exposed to an altered MHC environment. J Exp Med 207:2065-72
Blanchard, Nicolas; Kanaseki, Takayuki; Escobar, Hernando et al. (2010) Endoplasmic reticulum aminopeptidase associated with antigen processing defines the composition and structure of MHC class I peptide repertoire in normal and virus-infected cells. J Immunol 184:3033-42
Joncker, Nathalie T; Fernandez, Nadine C; Treiner, Emmanuel et al. (2009) NK cell responsiveness is tuned commensurate with the number of inhibitory receptors for self-MHC class I: the rheostat model. J Immunol 182:4572-80

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