Molecular Cloning and Functional Characterization of Tibetan Porcine STING

Zhiqing Huang,Xiangbing Mao,Ye Zhao,Keying Zhang,Xiaoling Chen,Bing Yu,Daiwen Chen

doi:10.3390/ijms13010506

Zhiqing Huang, Xiangbing Mao + Show 5 more

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https://doi.org/10.3390/ijms13010506

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Abstract

Tibetan pig is well known for its strong disease resistance. However, little is known about the molecular basis of its strong resistance to disease. Stimulator of interferon (IFN) genes (STING), also known as MPYS/MITA/ERIS/TMEM173, is an adaptor that functions downstream of RIG-I and MAVS and upstream of TBK1 and plays a critical role in type I IFN induction. Here we report the first cloning and characterization of STING gene from Tibetan pig. The entire open reading frame (ORF) of the Tibetan porcine STING is 1137 bp, with a higher degree of sequence similarity with Landrace pig (98%) and cattle (88%) than with chimpanzee (84%), human (83%) or mouse (77%). The predicted protein is composed of 378 amino acids and has 4 putative transmembrane domains. Real-time quantitative PCR analysis indicated that Tibetan pig STING mRNA was most abundant in the lung and heart. Overexpression of Tibetan porcine STING led to upregulation of IFN-β and IFN-stimulated gene 15 (ISG15) in porcine jejunal epithelial cell line IPEC-J2 cells. This is the first study investigating the biological role of STING in intestinal epithelial cells, which lays a foundation for the further study of STING in intestinal innate immunity.

Highlights

Innate immunity is the first line of host defense against invading pathogens
pattern recognition receptors (PRRs) trigger a series of signaling events leading to the expression of type I interferons (IFNs), IFN-stimulated genes (ISGs) and proinflammatory cytokines, which are all critical for the protection of a host suffering from microbial infection [4]
We examined the effects of Stimulator of interferon (IFN) genes (STING) on IFN-β and IFN-stimulated gene 15 (ISG15) expressions at mRNA levels

Summary

Introduction

Innate immunity is the first line of host defense against invading pathogens. Innate immune responses are initiated by the host’s pattern recognition receptors (PRRs), which recognize conserved pathogen-associated molecular patterns (PAMPs) of microorganisms [1,2,3]. PRRs trigger a series of signaling events leading to the expression of type I interferons (IFNs), IFN-stimulated genes (ISGs) and proinflammatory cytokines, which are all critical for the protection of a host suffering from microbial infection [4]. The host has developed at least two distinct mechanisms for the recognition of viral RNAs, which represents the first step of innate antiviral response [5]. One is mediated by Toll-like receptors (TLRs), such as TLR3, which recognizes viral double-stranded RNA (dsRNA) released by infected cells [6]. The other mechanism involves the RNA helicases RIG-I and MDA5, which function as intracellular viral RNA sensors [7,8]

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