MicroRNA-221 restricts human cytomegalovirus replication via promoting type I IFN production by targeting SOCS1/NF-?B pathway.
ABSTRACT: HCMV is a common pathogen for human with relatively high prevalence, which could be life-threatened in immunodeficient patients and lead to significant birth defects in newborns. In this study, we firstly report that HCMV infection significantly enhances the expression of microRNA-221 (miR-221) in Neural Precursor Cells (NPCs). We found that miR-221 directly targets at the 3'-UTR of suppressor of cytokine signaling 1 (SOCS1) and suppresses SOCS1 expression at the both mRNA and protein levels. MiR-221 overexpression restrained HCMV replication by promoting type I interferon (IFN) and interferon stimulating genes (ISGs) production, whereas reintroduction of SOCS1 abrogated the miR-221-induced effects on HCMV replication. Importantly, miR-221 positively regulated the phosphorylation and activation of NF-?B by suppressing SOCS1. What's more, miR-221 agomir alleviated MCMV-induced tissue injury by promoting type I IFN antiviral activities in vivo. Thus, miR-221 modulates the infection and replication of HCMV as an intrinsic antiviral factor, and could be developed as a treatment target for anti-HCMV treatment.
Project description:Porcine epidemic diarrhea virus (PEDV) is an economically important pathogen that has evolved several mechanisms to evade type I IFN responses. Type III interferon (IFN-?), an innate cytokine that primarily targets the mucosal epithelia, is critical in fighting mucosal infection in the host and has been reported to potently inhibit PEDV infection in vitro. However, how PEDV escapes IFN-? antiviral response remains unclear. In this study, we found that PEDV infection induced significant IFN-? expression in type I IFN-defective Vero E6 cells, but virus-induced endogenous IFN-? did not reduce PEDV titers. Moreover, we demonstrated that PEDV escaped IFN-? responses by substantially upregulating the suppressor of cytokine signaling protein 1 (SOCS1) expression, which impaired the induction of IFN-stimulated genes (ISGs) and dampened the IFN-? antiviral response and facilitated PEDV replication in Vero E6 cells. We further showed that PEDV infection increased SOCS1 expression by decreasing host miR-30c-5p expression. MiR-30c-5p suppressed SOCS1 expression through targeting the 3' untranslated region (UTR) of SOCS1. The inhibition of IFN-? elicited ISGs expression by SOCS1 was specifically rescued by overexpression of miR-30c-5p. Collectively, our findings identify a new strategy by PEDV to escape IFN-?-mediated antiviral immune responses by engaging the SOCS1/miR-30c axis, thus improving our understanding of its pathogenesis.
Project description:In host innate immunity, type I interferons (IFN-I) are major antiviral molecules, and coronaviruses have evolved diverse strategies to counter the IFN-I response during infection. Transmissible gastroenteritis virus (TGEV), a member of the Alphacoronavirus family, induces endoplasmic reticulum (ER) stress and significant IFN-I production after infection. However, how TGEV evades the IFN-I antiviral response despite the marked induction of endogenous IFN-I has remained unclear. Inositol-requiring enzyme 1 ? (IRE1?), a highly conserved ER stress sensor with both kinase and RNase activities, is involved in the IFN response. In this study, IRE1? facilitated TGEV replication via downmodulating the host microRNA (miR) miR-30a-5p abundance. miR-30a-5p normally enhances IFN-I antiviral activity by directly targeting the negative regulators of Janus family kinase (JAK)-signal transducer and activator of transcription (STAT), the suppressor of cytokine signaling protein 1 (SOCS1), and SOCS3. Furthermore, TGEV infection increased SOCS1 and SOCS3 expression, which dampened the IFN-I antiviral response and facilitated TGEV replication. Importantly, compared with mock infection, TGEV infection in vivo resulted in decreased miR-30a-5p levels and significantly elevated SOCS1 and SOCS3 expression in the piglet ileum. Taken together, our data reveal a new strategy used by TGEV to escape the IFN-I response by engaging the IRE1?-miR-30a-5p/SOCS1/3 axis, thus improving our understanding of how TGEV escapes host innate immune defenses.IMPORTANCE Type I interferons (IFN-I) play essential roles in restricting viral infections. Coronavirus infection induces ER stress and the interferon response, which reflects different adaptive cellular processes. An understanding of how coronavirus-elicited ER stress is actively involved in viral replication and manipulates the host IFN-I response has remained elusive. Here, TGEV inhibited host miR-30a-5p via the ER stress sensor IRE1?, which led to the increased expression of negative regulators of JAK-STAT signaling cascades, namely, SOCS1 and SOCS3. Increased SOCS1 or SOCS3 expression impaired the IFN-I antiviral response, promoting TGEV replication. These findings enhance our understanding of the strategies used by coronaviruses to antagonize IFN-I innate immunity via IRE1?-mediated manipulation of the miR-30a-5p/SOCS axis, highlighting the crucial role of IRE1? in innate antiviral resistance and the potential of IRE1? as a novel target against coronavirus infection.
Project description:BACKGROUND:Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infection in infants, children, immunocompromised adults, and elderly individuals. Currently, there are few therapeutic options available to prevent RSV infection. The present study aimed to investigate the effects of luteolin on RSV replication and the related mechanisms. MATERIAL AND METHODS:We pretreated cells and mice with luteolin before infection with RSV, the virus titer, expressions of RSV-F, interferon (IFN)-stimulated genes (ISGs), and production of IFN-? and IFN-? were determined by plaque assay, RT-qPCR, and ELISA, respectively. The activation of Janus kinase (JAK)-signal transducer and activator of transcription 1 (STAT1) signaling pathway was detected by Western blotting and luciferase assay. Proteins which negatively regulate STAT1 were determined by Western blotting. Then cells were transfected with suppressor of cytokine signaling 1 (SOCS1) plasmid and virus replication and ISGs expression were determined. Luciferase reporter assay and Western blotting were performed to detect the relationship between SOCS1 and miR-155. RESULTS:Luteolin inhibited RSV replication, as shown by the decreased viral titer and RSV-F mRNA expression both in vitro and in vivo. The antiviral activity of luteolin was attributed to the enhanced phosphorylation of STAT1, resulting in the increased production of ISGs. Further study showed that SOCS1 was downregulated by luteolin and SOCS1 is a direct target of microRNA-155 (miR-155). Inhibition of miR-155 rescued luteolin-mediated SOCS1 downregulation, whereas upregulation of miR-155 enhanced the inhibitory effect of luteolin. CONCLUSION:Luteolin inhibits RSV replication by regulating the miR-155/SOCS1/STAT1 signaling pathway.
Project description:Respiratory syncytial virus (RSV) infection upregulates genes of the suppressor of cytokine signaling (SOCS) family, which utilize a feedback loop to inhibit type I interferon dependent antiviral signaling pathway. Here, we reconstituted RSV nonstructural (NS) protein expression plasmids (pNS1, pNS2, and pNS1/2) and tested whether NS1 or NS2 would trigger SOCS1 and SOCS3 protein expression. These NS proteins inhibited interferon- (IFN-) ? signaling through a mechanism involving the induction of SOCS1 and SOCS3, which appeared to be different from autocrine IFN dependent. NS1 induced both SOCS1 and SOCS3 upregulation, while NS2 only induced SOCS1 expression. The induced expression of SOCS1 and SOCS3 preceded endogenous IFN-signaling activation and inhibited the IFN-inducible antiviral response as well as chemokine induction. Treatments with INF-? and NS proteins both induced SOCS1 expression; however, they had opposing effects on IFN-?-dependent antiviral gene expression. Our results indicate that NS1 and NS2, which induce the expression of SOCS1 or SOCS3, might represent an independent pathway of stimulating endogenous IFN signaling.
Project description:Gamma interferon (IFN-?) is known to negatively regulate murine gammaherpesvirus-68 (MHV-68 or ?HV-68) replication. This process involves the suppression of the viral gene replication and transcription activator (RTA) promoter, as well as activation of signal transducers and activators of transcription (STAT1). Notably, this effect is gradually attenuated during MHV-68 infection of bone marrow-derived macrophages (BMMs), which raised the possibility that the virus may utilize a mechanism that counteracts the antiviral effect of IFN-?. By identifying the cellular factors that negatively regulate JAK-STAT1 signaling, we revealed that the infection of BMMs by MHV-68 induces the expression of suppressor of cytokine signaling 1 (SOCS1) and that depletion of SOCS1 restores the inhibitory effect of IFN-? on virus replication. Moreover, we demonstrated that the expression of SOCS1 was induced as a result of the Toll-like receptor 3 (TLR3) mediated activation of the NF-?B signaling cascade. In conclusion, we report that TLR3-TRAF-NF-?B signaling pathway play a role in the induction of SOCS1 that counteracts the antiviral effect of IFN-? during MHV-68 infection. This process is cell type-specific: it is functional in macrophages, but not in epithelial cells or fibroblasts. Our study reveals a mechanism that balances the immune responses and the escape of a gamma-herpesvirus in some antigen-presenting cells.
Project description:Influenza A virus (IAV) has evolved multiple mechanisms to compromise type I interferon (IFN) responses. The antiviral function of IFN is mainly exerted by activating the JAK/STAT signalling and subsequently inducing IFN-stimulated gene (ISG) production. However, the mechanism by which IAV combat the type I IFN signalling pathway is not fully elucidated. In this study, we explored the roles of human microRNAs modulated by IAV infection in type I IFN responses. We demonstrated that microRNA-30 (miR-30) family members were downregulated by IAV infection. Our data showed that the forced expression of miR-30 family members inhibited IAV proliferation, while miR-30 family member inhibitors promoted IAV proliferation. Mechanistically, we found that miR-30 family members targeted and reduced SOCS1 and SOCS3 expression, and thus relieved their inhibiting effects on IFN/JAK/STAT signalling pathway. In addition, miR-30 family members inhibited the expression of NEDD4, a negative regulator of IFITM3, which is important for host defence against influenza viruses. Our findings suggest that IAV utilises a novel strategy to restrain host type I IFN-mediated antiviral immune responses by decreasing the expression of miR-30 family members, and add a new way to understand the mechanism of immune escape caused by influenza viruses.
Project description:Acute obstructive cholangitis (AOC) is a common and severe infectious diseases that occurs in an obstructed biliary system. The suppressors of cytokine signaling (SOCS) family include well-known negative regulators of cytokine receptor signaling. However, few studies have been conducted to determine their function in AOC. In this study, we showed that SOCS1 expression aberrantly changed and was associated with AOC prognosis in rat models. Decreased SOCS1 expression enhances regenerative response after biliary drainage (BD) resulting from AOC by upregulating hepatocyte growth factor (HGF) signaling. To detect SOCS1 expression in the liver less invasively and to predict the prognosis for AOC after BD, miR-221 and miR-222 were investigated. Ectopic SOCS1 expression indirectly decreases miR-221/222 expression through Met in vitro. An inverse correlation between SOCS1 expression and miR-221/222 expression in liver tissue or in serum was verified in rats. Serum from AOC patients showed that lower expression of circulating miR-221/222 after endoscopic nasobiliary drainage was associated with delayed restoration of liver function. Our results showed that SOCS1 regulates hepatic regenerative response, and indirectly detecting downstream molecules, such as miR-221/222, may provide prognostic makers for AOC.
Project description:Infectious bursal disease (IBD) is an acute, highly contagious, and immunosuppressive avian disease caused by IBD virus (IBDV). MicroRNAs (miRNAs) are involved in host-pathogen interactions and innate immune response to viral infection. However, the role of miRNAs in host response to IBDV infection is not clear. We report here that gga-miR-155 acts as an anti-virus host factor inhibiting IBDV replication. We found that transfection of DF-1 cells with gga-miR-155 suppressed IBDV replication, while blockage of the endogenous gga-miR-155 by inhibitors enhanced IBDV replication. Furthermore, our data showed that gga-miR-155 enhanced the expression of type I interferon in DF-1 cells post IBDV infection. Importantly, we found that gga-miR-155 enhanced type I interferon expression via targeting SOCS1 and TANK, two negative regulators of type I IFN signaling. These results indicate that gga-miR-155 plays a critical role in cell response to IBDV infection.
Project description:Staphylococcal enterotoxin B (SEB) causes food poisoning in humans. It is considered a biological weapon, and inhalation can trigger lung injury and sometimes respiratory failure. Being a superantigen, SEB initiates an exaggerated inflammatory response. While the role of microRNAs (miRNAs) in immune cell activation is getting increasing recognition, their role in the regulation of inflammatory disease induced by SEB has not been studied. In this investigation, we demonstrate that exposure to SEB by inhalation results in acute inflammatory lung injury accompanied by an altered miRNA expression profile in lung-infiltrating cells. Among the miRNAs that were significantly elevated, miR-155 was the most overexpressed. Interestingly, miR-155(-/-) mice were protected from SEB-mediated inflammation and lung injury. Further studies revealed a functional link between SEB-induced miR-155 and proinflammatory cytokine gamma interferon (IFN-?). Through the use of bioinformatics tools, suppressor of cytokine signaling 1 (SOCS1), a negative regulator of IFN-?, was identified as a potential target of miR-155. While miR-155(-/-) mice displayed increased expression of Socs1, the overexpression of miR-155 led to its suppression, thereby enhancing IFN-? levels. Additionally, the inhibition of miR-155 resulted in restored Socs1expression. Together, our data demonstrate an important role for miR-155 in promoting SEB-mediated inflammation in the lungs through Socs1 suppression and suggest that miR-155 may be an important target in preventing SEB-mediated inflammation and tissue injury.
Project description:The biological basis of essential thrombocythemia (ET) patients lacking known mutations is still unknown. MicroRNAs (miRNA) regulate hematopoietic differentiation and are deregulated in several hematopoietic malignancies. However, miRNA expression in ET patients has been poorly explored. We performed miRNA profiling in platelets from 19 ET patients and 10 healthy controls. Hierarchical cluster analysis showed two well-separated clusters between patients and controls, indicating that ET platelets had a characteristic 70-miRNA signature (P<0.0001), 68 of which were downregulated. According to the mutational status, three differentially expressed miRNAs, miR-15a (P=0.045), miR-150 (P=0.001) and miR-519a (P=0.036), were identified. A 40-miRNA signature was identified characterizing JAK2V617F-positive ET patients. Eight genes, whose interaction with the miRNAs could activate the JAK/STAT pathway were identified. An inverse correlation was observed between miRNAs expression and their target genes for SOCS1 and miR-221, SOCS3 and miR-221, SOCS3 and miR-203, and PTPN11 and miR-23a. All three miRNAs were upregulated in JAK2V617F-negative ET patients. SOCS1 and SOCS3 were validated as targets of miR-221 and miR-203, respectively. In summary, our study shows that platelets from JAK2V617F-negative ET patients harbor a specific miRNA signature that can participate in the modulation of the JAK/STAT pathway through regulation of key genes as SOCS1 and SOCS3.