TLR3, TICAM1 and human rhinovirus infection Human rhinovirus (RV) infection is associated with the common cold and asthma development and/or exacerbation. To date, we and others have reported a complex of RV-induced epithelial proinflammatory and antiviral pathways, which involve TLR3, RIG1, MDA5 and PKR. Recently, we have shown that TLR3 activation appears to be upstream of all other pathways, and TLR3 desensitization via TICAM1 degradation is critical to antiviral defense by airway epithelium. To further elucidate the underlying mechanism, we propose to first determine the impact of TLR3 desensitization on epithelial anti-viral defense in vitro. In this study, we will determine the kinetics of TICAM1 protein turnover and its downstream cellular antiviral responses induced by dsRNA or by RV. We will also determine the cellular antiviral status during this process. Lastly, we will overexpress TICAM1 to test if this could restore the cellular antiviral response. To evaluate the potential alteration of TLR3 desensitization in asthma, we will determine whether or not Th2-cytokine- treated epithelial cells have altered desensitization, and whether or not human asthmatic epithelial cells are defective in this process as compared to the normal cells. Then, we propose to determine the mechanistic basis of TICAM1 degradation. In this aim, we will test a novel hypothesis that TICAM1 is degraded via chaperone mediated autophagy. This is a high-risk and high-impact project that is well suited for R21 mechanism. If we succeed, we will be able to gain novel insight into the TLR3-TICAM1 mediated airway antiviral defense and to identify a risk factor for asthma exacerbation.

Public Health Relevance

Respiratory human rhinovirus infection is associated with common cold, the development of asthma and the exacerbations of asthma. Interferon production has been critical to restrict viral replication and asthmatic epithelium has been shown to be defective in the interferon response. In this study, we will test a novel hypothesize that TLR3-TICAM1 axis may become defective in asthma, thereby compromising the IFN production and antiviral defense, which may be an important pathogenic factor for asthma exacerbation. If succeed, we will be able to gain novel insight into the TLR3-TICAM1- mediated airway antiviral defense and to identify a risk factor for diagnosing and eventually developing effective treatment for asthma exacerbation.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Exploratory/Developmental Grants (R21)
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Innate Immunity and Inflammation (III)
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Davidson, Wendy F
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University of Arizona
Schools of Pharmacy
United States
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Chen, Yin; Vasquez, Monica M; Zhu, Lingxiang et al. (2017) Effects of Retinoids on Augmentation of Club Cell Secretory Protein. Am J Respir Crit Care Med 196:928-931
Zhou, Xu; Zhu, Lingxiang; Lizarraga, Rosa et al. (2017) Human Airway Epithelial Cells Direct Significant Rhinovirus Replication in Monocytic Cells by Enhancing ICAM1 Expression. Am J Respir Cell Mol Biol 57:216-225
Klionsky, Daniel J (see original citation for additional authors) (2016) Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition). Autophagy 12:1-222
Velichko, Sharlene; Zhou, Xu; Zhu, Lingxiang et al. (2016) A Novel Nuclear Function for the Interleukin-17 Signaling Adaptor Protein Act1. PLoS One 11:e0163323
Oslund, Karen L; Zhou, Xu; Lee, Boram et al. (2014) Synergistic up-regulation of CXCL10 by virus and IFN ? in human airway epithelial cells. PLoS One 9:e100978