Background: Retinoic acid-inducible gene 1-like receptors (RLRs) are a novel family of pattern recognition receptors that include retinoic acid-inducible gene 1 (RIG-1), melanoma differentiation-associated gene 5 (MDA-5), and laboratory of genomics and physiology 2 (LGP-2). The knowledge of RLRs and their function in the human airway is limited. This study explores the role of RLRs in the upper respiratory tract.
Methods: Tonsils, adenoids, nasal polyps, and biopsy specimens from the nasal mucosa were examined for the occurrence of the RIG-1, MDA-5, and LGP-2 using real-time reverse-transcription polymerase chain reaction and immunohistochemistry. The nasopharyngeal epithelial cell line FaDu was cultured with the RIG-1/MDA-5 ligand poly(I:C)/LyoVec (Invivogen, San Diego, CA) and analyzed for cytokine release using ELISA.
Results: RIG-1, MDA-5, and LGP-2 mRNA were found in all tissues tested. The airway epithelium appeared to be their most prominent location. The RIG-1 and MDA-5 mRNA levels were higher in nasal polyps than in normal nasal mucosa, a state that seemed to be reversed by local steroid treatment. Culture of FaDu with poly(I:C)/LyoVec resulted in IL-6 and IL-8 release. No alteration in RLR expression in tonsils was seen on infection.
Conclusion: This study shows the presence and functional activity of RLRs in the human upper airways. It also suggests a role for RLRs in nasal polyposis.
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http://dx.doi.org/10.2500/ajra.2011.25.3712 | DOI Listing |
Viruses
December 2024
Department of Biological Sciences, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA.
During virus infection, the activation of the antiviral endoribonuclease, ribonuclease L (RNase L), by a unique ligand 2'-5'-oilgoadenylate (2-5A) causes the cleavage of single-stranded viral and cellular RNA targets, restricting protein synthesis, activating stress response pathways, and promoting cell death to establish broad antiviral effects. The immunostimulatory dsRNA cleavage products of RNase L activity (RL RNAs) recruit diverse dsRNA sensors to activate signaling pathways to amplify interferon (IFN) production and activate inflammasome, but the sensors that promote cell death are not known. In this study, we found that DEAH-box polypeptide 15 (DHX15) and retinoic acid-inducible gene I (Rig-I) are essential for apoptosis induced by RL RNAs and require mitochondrial antiviral signaling (MAVS), c-Jun amino terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK) for caspase-3-mediated intrinsic apoptosis.
View Article and Find Full Text PDFMedComm (2020)
January 2025
Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that is primarily known for causing severe joint and muscle symptoms, but its pathological effects have extended beyond these tissues. In this study, we conducted a comprehensive proteomic analysis across various organs in rodent and nonhuman primate models to investigate CHIKV's impact on organs beyond joints and muscles and to identify key host factors involved in its pathogenesis. Our findings reveal significant species-specific similarities and differences in immune responses and metabolic regulation, with proteins like Interferon-Stimulated Gene 15 (ISG15) and Retinoic Acid-Inducible Gene I (RIG-I) playing crucial roles in the anti-CHIKV defense.
View Article and Find Full Text PDFiScience
November 2024
Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071, China.
Angew Chem Int Ed Engl
January 2025
University of Chicago Division of the Physical Sciences, chemistry, UNITED STATES OF AMERICA.
Immune checkpoint blockade (ICB) has revolutionized the treatment of many cancers by leveraging the immune system to combat malignancies. However, its efficacy is limited by the immunosuppressive tumor microenvironment and other regulatory mechanisms of the immune system. Innate immune modulators (IIMs) provide potent immune activation to complement adaptive immune responses and help overcome resistance to ICB.
View Article and Find Full Text PDFPoult Sci
December 2024
Graduate School of International Agricultural Technology and Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang-gun, Gangwon-do 25354, South Korea; Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang-gun, Gangwon-do 25354, South Korea. Electronic address:
Retinoic acid inducible gene I (RIG-I) is an innate immune RNA sensor which can detect viral infection such as influenza viruses. Duck but not chicken has an RIG-I gene. However, the immune responses could be induced in chicken cells by transferring the duck RIG-I transgene.
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