PAR-1 contributes to the innate immune response during viral infection
Silvio Antoniak, … , Ursula Rauch, Nigel Mackman
Silvio Antoniak, … , Ursula Rauch, Nigel Mackman
Published February 8, 2013
Citation Information: J Clin Invest. 2013;123(3):1310-1322. https://doi.org/10.1172/JCI66125.
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Research Article Immunology

PAR-1 contributes to the innate immune response during viral infection

Abstract

Coagulation is a host defense system that limits the spread of pathogens. Coagulation proteases, such as thrombin, also activate cells by cleaving PARs. In this study, we analyzed the role of PAR-1 in coxsackievirus B3–induced (CVB3-induced) myocarditis and influenza A infection. CVB3-infected Par1–/– mice expressed reduced levels of IFN-β and CXCL10 during the early phase of infection compared with Par1+/+ mice that resulted in higher viral loads and cardiac injury at day 8 after infection. Inhibition of either tissue factor or thrombin in WT mice also significantly increased CVB3 levels in the heart and cardiac injury compared with controls. BM transplantation experiments demonstrated that PAR-1 in nonhematopoietic cells protected mice from CVB3 infection. Transgenic mice overexpressing PAR-1 in cardiomyocytes had reduced CVB3-induced myocarditis. We found that cooperative signaling between PAR-1 and TLR3 in mouse cardiac fibroblasts enhanced activation of p38 and induction of IFN-β and CXCL10 expression. Par1–/– mice also had decreased CXCL10 expression and increased viral levels in the lung after influenza A infection compared with Par1+/+ mice. Our results indicate that the tissue factor/thrombin/PAR-1 pathway enhances IFN-β expression and contributes to the innate immune response during single-stranded RNA viral infection.

Authors

Silvio Antoniak, A. Phillip Owens III, Martin Baunacke, Julie C. Williams, Rebecca D. Lee, Alice Weithäuser, Patricia A. Sheridan, Ronny Malz, James P. Luyendyk, Denise A. Esserman, JoAnn Trejo, Daniel Kirchhofer, Burns C. Blaxall, Rafal Pawlinski, Melinda A. Beck, Ursula Rauch, Nigel Mackman

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Figure 8

Effect of PAR-1 activation on poly I:C activation of p38 and induction of Ifnb1 mRNA expression.

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Effect of PAR-1 activation on poly I:C activation of p38 and induction o...
(A) Levels of phosphorylated p38 in Par1+/+ and Par1–/– CFs before and after stimulation with 200 μM agonist peptide (AP) and/or 25 μg/ml poly I:C for the indicated times. Phosphorylated p38 levels (normalized to GAPDH) are shown relative to unstimulated Par1+/+ cells. Representative Western blots are also shown. (B) Levels of SEAP in the culture media of HEK-293 cells stimulated with 25 μg/ml poly I:C and/or 100 or 200 μM agonist peptide for 24 hours. Data are shown from 12 independent samples per group. (C) Ifnb1 mRNA expression in Par1+/+ (white bars) and Par1–/– (black bars) CFs before and after stimulation with 25 μg/ml poly I:C and/or 200 μM agonist peptide for 2 hours. Results are shown relative to poly I:C–stimulated Par1+/+ CFs. The p38 inhibitor SB203580 (SB; 10 μM) was added 30 minutes prior to poly I:C stimulation. Data (mean ± SEM; n = 5–9 independent experiments) were analyzed by linear mixed models with a random intercept (A) or by 1-way (B) or 2-way (C) ANOVA. *P < 0.05, Par1+/+ vs. Par1–/–; #P < 0.05 vs. unstimulated control within the same genotype; †P < 0.05 versus poly I:C alone within the same genotype; §P < 0.05 vs. poly I:C and agonist peptide.