Inhibition of EHMT2 Induces a Robust Antiviral Response Against Foot-and-Mouth Disease and Vesicular Stomatitis Virus Infections in Bovine Cells.

Abstract

The genetic regulatory network controlling the innate immune system is well understood in many species. However, the role of the epigenetic mechanisms underlying the expression of immunoregulatory genes is less clear, especially in livestock species. Histone H3 lysine 9 dimethylation (H3K9me2) is an epigenetic modification associated with transcriptional silencing within the euchromatin regions. Euchromatic histone-lysine N-methyltransferase 2 (EHMT2; also known as G9a) is a crucial enzyme responsible for regulating the dynamics of this epigenetic modification. It has been shown that histone modifications play a role in regulating type I interferon (IFN) response. In the present study, we investigated the role of EHMT2 in the epigenetic regulation of bovine antiviral innate immunity and explored its therapeutic potential against viral infections. We evaluated the effects of pharmacological and RNAi-mediated inhibition of EHMT2 on the transcription of IFN-β and other IFN-inducible antiviral genes, as well as its effect on foot-and-mouth disease virus (FMDV) and vesicular stomatitis virus (VSV) replication in bovine cells. We show that treatment of primary bovine cells with the synthetic EHMT2 inhibitor (UNC0638) either before or shortly after virus infection resulted in a significant increase in transcript levels of bovine IFN-β (boIFN-β; 300-fold) and other IFN-inducible genes, including IFN-stimulated gene 15 (ISG-15), myxovirus resistance 1 (Mx-1), Mx-2, RIG-I, 2',5'-oligoadenylate synthetase 1 (OAS-1), and protein kinase R (PKR). Expression of these factors correlated with a significant decrease in VSV and FMDV viral titers. Our data confirm the involvement of EHMT2 in the epigenetic regulation of boIFN-β and demonstrate the activation of a general antiviral state after EHMT2 inhibition.

• Authors: Neetu Singh, Lisbeth Ramĩrez-Carvajal, Teresa de Los Santos, Michael C Golding, Charles R Long
• Journal: Journal of interferon & cytokine research : the official journal of the International Society for Interferon and Cytokine Research (J Interferon Cytokine Res) Vol. 36 Issue 1 Pg. 37-47 (Jan 2016) ISSN: 1557-7465 [Electronic] United States
• PMID: 26418342 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Euchromatin
• Histocompatibility Antigens
• Myxovirus Resistance Proteins
• Quinazolines
• RNA, Messenger
• RNA, Small Interfering
• UNC 0638
• Ubiquitins
• Interferon-beta
• Histone-Lysine N-Methyltransferase
• eIF-2 Kinase
• 2',5'-Oligoadenylate Synthetase
• DEAD-box RNA Helicases
• Poly I-C

Topics

• 2',5'-Oligoadenylate Synthetase (genetics, immunology)
• Animals
• Cattle
• Cell Line
• DEAD-box RNA Helicases (genetics, immunology)
• Epigenesis, Genetic
• Epithelial Cells (drug effects, immunology, virology)
• Euchromatin (chemistry, drug effects, metabolism)
• Fetus
• Fibroblasts (drug effects, immunology, virology)
• Foot-and-Mouth Disease Virus (drug effects, growth & development, immunology)
• Histocompatibility Antigens (genetics, immunology)
• Histone-Lysine N-Methyltransferase (antagonists & inhibitors, genetics, immunology)
• Immunity, Innate
• Interferon-beta (immunology, pharmacology)
• Myxovirus Resistance Proteins (genetics, immunology)
• Poly I-C (pharmacology)
• Primary Cell Culture
• Quinazolines (pharmacology)
• RNA, Messenger (genetics, immunology)
• RNA, Small Interfering (genetics, metabolism)
• Transcription, Genetic
• Ubiquitins (genetics, immunology)
• Vesicular stomatitis Indiana virus (drug effects, growth & development, immunology)
• eIF-2 Kinase (genetics, immunology)