Chicken STING Mediates Activation of the IFN Gene Independently of the RIG-I Gene.

Abstract

Stimulator of IFN genes (STING) is an adaptor that functions downstream of retinoic acid-inducible gene I (RIG-I) in mammalian cells; however, RIG-I is absent in chickens. We identified chicken STING (chSTING) as a critical mediator of virus-triggered type I IFN signaling in RIG-I-null chicken cells. Overexpression of chSTING in DF-1 cells inhibited Newcastle disease virus and avian influenza virus (AIV) viral replication and activated IRF-7 and NF-κB to induce expression of type I IFNs. Knockdown of endogenous chSTING abolished virus-triggered activation of IRF-7 and IFN-β and increased viral yield. chSTING was a critical component in the virus-triggered IRF-7 activation pathway and the cellular antiviral response. chSTING predominantly localized to the outer membrane of the endoplasmic reticulum and was also found in the mitochondrial membrane. Furthermore, knockdown of chSTING blocked polyinosinic-polycytidylic acid-, poly(deoxyadenylic-deoxythymidylic) acid-, and melanoma differentiation-associated gene 5 (MDA5)-stimulated induction of IFN-β. Coimmunoprecipitation experiments indicated that chicken MDA5 could interact with chSTING, and this interaction was enhanced by ectopically expressed chicken mitochondrial antiviral-signaling protein. Together, these results indicated that chSTING is an important regulator of chicken innate immune signaling and might be involved in the MDA5 signaling pathway in chicken cells. These results help with understanding the biological role of STING in innate immunity during evolution.

• Authors: Yuqiang Cheng, Yingjie Sun, Hengan Wang, Yaxian Yan, Chan Ding, Jianhe Sun
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 195 Issue 8 Pg. 3922-36 (Oct 15 2015) ISSN: 1550-6606 [Electronic] United States
• PMID: 26392466 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 by The American Association of Immunologists, Inc.

Chemical References

• Avian Proteins
• Membrane Proteins
• Interferon-beta
• DEAD-box RNA Helicases
• Poly I-C

Topics

• Animals
• Avian Proteins (genetics, immunology)
• Biological Evolution
• Chickens
• DEAD-box RNA Helicases (genetics, immunology)
• Immunity, Innate (drug effects, genetics)
• Influenza A Virus, H9N2 Subtype (immunology)
• Influenza in Birds (genetics, immunology)
• Interferon-beta (genetics, immunology)
• Membrane Proteins (genetics, immunology)
• Poly I-C (pharmacology)
• Signal Transduction (drug effects, genetics, immunology)