Cytokine production by the Th1 and Th2 subsets has been associated with susceptibility to infectious, allergic, and autoimmune diseases. Understanding the molecular events which control lineage-specific cytokine expression would provide useful tools to modulate the Th1/Th2 response. IL- 4 production by Th2 cells is regulated by NFAT and the NFAT cofactor, NIP45. We have shown that arginine methylation of NIP45 facilitates its interaction with NFAT and augments IL-4 transcription. Our data positioned the arginine methyltransferase PRMT1 downstream of the T cell receptor, suggesting that arginine methylation may be an important modification in immune receptor signaling pathways. Arginine methylation is countered by the actions of peptidylarginine deiminase 4 (PAD4). The five PAD enzymes convert arginine residues within proteins into the atypical amino acid citrulline. PAD4 is expressed mainly in lymphocytes. We have found that NIP45 methylation is negatively regulated by PAD4 via citrullination of arginine residues, which prevents the ability of NIP45 to be methylated by PRMT1. PAD4 expression dramatically reduces NIP45-induced IL-4 promoter activity. Therefore, we hypothesize that through actions on NIP45 and other regulatory proteins that PAD4 controls Th cell cytokine expression.
The specific aims are: 1) Determine the mechanism by which PAD4 antagonizes NIP45-mediated induction of Th cell cytokine production. We will (i) determine the modified arginine residues in NIP45 by mass spectrometry, (ii) determine how PAD4 influences NIP45 activity by studying the effects of PAD4 on the NIP45/NFAT interaction, (iii) determine whether citrullination within NIP45 serves a function other than preventing methylation. 2) Investigate the regulation of PAD4 activity. We will: (i) determine the PAD4 expression pattern in Th cells, (ii) determine whether PAD4 activity is regulated in Th cells, (iii) determine whether PAD4, itself, is regulated by arginine methylation. 3) Analyze the phenotype of PAD4 deficient mice. We will create mice in which exons 7-13 of PAD4 are flanked by loxP sites so that we can ablate PAD4 expression in the T lineage using CD4-Cre Tg mice. These mice will allow us to determine the role of PAD4 in Th cell function. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI067460-01
Application #
7016752
Study Section
Cellular and Molecular Immunology - B (CMI)
Program Officer
Rathbun, Gary
Project Start
2006-02-01
Project End
2011-01-31
Budget Start
2006-02-01
Budget End
2007-01-31
Support Year
1
Fiscal Year
2006
Total Cost
$464,750
Indirect Cost
Name
Scripps Research Institute
Department
Type
DUNS #
781613492
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Fernandez-Castaneda, Anthony; Arandjelovic, Sanja; Stiles, Travis L et al. (2013) Identification of the low density lipoprotein (LDL) receptor-related protein-1 interactome in central nervous system myelin suggests a role in the clearance of necrotic cell debris. J Biol Chem 288:4538-48
Dillon, Myles B C; Rust, Heather L; Thompson, Paul R et al. (2013) Automethylation of protein arginine methyltransferase 8 (PRMT8) regulates activity by impeding S-adenosylmethionine sensitivity. J Biol Chem 288:27872-80
MacLeod, Amanda S; Hemmers, Saskia; Garijo, Olivia et al. (2013) Dendritic epidermal T cells regulate skin antimicrobial barrier function. J Clin Invest 123:4364-74
Rohrbach, Amanda S; Slade, Daniel J; Thompson, Paul R et al. (2012) Activation of PAD4 in NET formation. Front Immunol 3:360
Dillon, Myles B C; Bachovchin, Daniel A; Brown, Steven J et al. (2012) Novel inhibitors for PRMT1 discovered by high-throughput screening using activity-based fluorescence polarization. ACS Chem Biol 7:1198-204
Rohrbach, Amanda S; Hemmers, Saskia; Arandjelovic, Sanja et al. (2012) PAD4 is not essential for disease in the K/BxN murine autoantibody-mediated model of arthritis. Arthritis Res Ther 14:R104
Arandjelovic, Sanja; McKenney, Katherine R; Leming, Sunamita S et al. (2012) ATP induces protein arginine deiminase 2-dependent citrullination in mast cells through the P2X7 purinergic receptor. J Immunol 189:4112-22
Hemmers, Saskia; Teijaro, John R; Arandjelovic, Sanja et al. (2011) PAD4-mediated neutrophil extracellular trap formation is not required for immunity against influenza infection. PLoS One 6:e22043
Fathman, John W; Gurish, Michael F; Hemmers, Saskia et al. (2010) NIP45 controls the magnitude of the type 2 T helper cell response. Proc Natl Acad Sci U S A 107:3663-8
Bonham, Kevin; Hemmers, Saskia; Lim, Yeon-Hee et al. (2010) Effects of a novel arginine methyltransferase inhibitor on T-helper cell cytokine production. FEBS J 277:2096-108

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