Project description:A major unanswered question in the current global coronavirus disease 2019 (COVID-19) outbreak is why severe disease develops in a small minority of infected individuals. In the current article, we report that homozygosity for the C allele of rs12252 in the interferon-induced transmembrane protein 3 (IFITM3) gene is associated with more severe disease in an age-dependent manner. This supports a role for IFITM3 in disease pathogenesis and the opportunity for early targeted intervention in at-risk individuals.
Project description:Interferon-induced transmembrane proteins (IFITMs) are broad-spectrum antiviral proteins that inhibit numerous virus infections by impeding viral entry into target cells. However, increasing evidence suggests diverse functions of IFITMs in virus infection, especially with the coronavirus. We analyzed the effect of chicken interferon-induced transmembrane proteins (chIFITMs) on coronavirus infectious bronchitis virus (IBV) infection in vitro. We demonstrated that the antiviral effects of IFITMs are dependent on cell and virus types. The overexpression of chIFITM1 dramatically promoted the replication of IBV Beaudette strain in the chicken hepatocellular carcinoma cell line, LMH. Mechanistically, chIFITMs share roughly the same subcellular localization in different host cells, and overexpressed of chIFITM1 have no effect of viral attachment and entry. Further studies revealed that mutations of amino acids at key positions (60KSRD63, 68KDFV71) in the intracellular loop domain (CIL) caused loss of the promoted function. Interaction with downstream proteins in co-response to viral infection could be the primary reason behind variable functions of chIFITM1 in different cells. In all, our study explored the functions of chIFITMs in viral infection from a new perspective.
Project description:ObjectiveThe study aimed to investigate the over expression of IFITM3 in hepatocellular carcinoma Egyptian patients.BackgroundHepatocellular carcinoma (HCC) continues to be a serious disease burden. Interferon Induced Transmembrane protein 3 (IFITM3) is a protein that encoded in humans by the IFITM3 gene. It plays a critical role in the immune system's defense, responsible for a large portion of the antiviral activity. In this study, we showed that IFITM3 rs 12252-CC was over expressed in HCC patients compared to control group with HCV infection.MethodDNA sequencing was applied for detection of IFITM3 rs 12252-CC and IFITM3 protein level was measured by ELISA to 50 patients with HCC with cirrhosis and 50 with Hepatitis C virus infection.ResultsThe obtained results of this study indicated that IFITM3 rs 12252-CC was significantly elevated in HCC group, the codominant model of CC genotype of IFITM3 gene had high association with risk of hepatocellular carcinoma with odd ratio (OR) = 2.70, p = 0.041.ConclusionIFITM3 play an important role in progression of hepatocellular carcinoma. Results revealed that IFITM3 rs 12252-CC among Hepatocellular carcinoma patients would allow diagnosis and starting intervention.
Project description:The interferon-induced transmembrane (IFITM) proteins are a family of small membrane proteins that inhibit the cellular entry of several genera of viruses. These proteins had been predicted to adopt a two-pass, type III transmembrane topology with an intracellular loop, two transmembrane helices (TM1 and TM2), and extracellular N and C termini. Recent work, however, supports an intramembrane topology for the helices with cytosolic orientation of both termini. Here we determined the topology of murine Ifitm3. We found that the N terminus of Ifitm3 could be stained by antibodies at the cell surface but that this conformation was cell type-dependent and represented a minority of the total plasma membrane pool. In contrast, the C terminus was readily accessible to antibodies at the cell surface and extracellular C termini comprised most or all of those present at the plasma membrane. The addition of a C-terminal KDEL endoplasmic reticulum retention motif to Ifitm3 resulted in sequestration of Ifitm3 in the ER, demonstrating an ER-luminal orientation of the C terminus. C-terminal, but not N-terminal, epitope tags were also degraded within lysosomes, consistent with their luminal orientation. Furthermore, epitope-tagged Ifitm3 TM2 functioned as a signal anchor sequence when expressed in isolation. Collectively, our results demonstrate a type II transmembrane topology for Ifitm3 and will provide insight into its interaction with potential targets and cofactors.
Project description:Objective: To study the potential effect of COVID-19 on the endometrium of affected symptomatic women. Design: Preliminary study of the endometrial transcriptomes in women with COVID-19 through RNA sequencing. Setting: Hospital and university laboratories. Subjects: Women with COVID-19 lacking SARS-CoV-2 infection in endometrial tissue. Intervention/Exposure: Endometrial biopsy collection. Main outcomes measures: Endometrial gene expression and functional analysis of patients with COVID-19 versus uninfected individuals. Results: COVID-19 systemic disease alters endometrial gene expression in 75% of women, with patients exhibiting a preponderance of 163 up-regulated (e.g., UTS2, IFI6, IFIH1, BNIP3) and 72 down-regulated genes (e.g., CPZ, CDH3, IRF4) (FDR<0.05). A total of 161 dysregulated functions (36 up-regulated and 125 down-regulated) were typically enriched in COVID-19 endometria, including upregulation in pathways involved in response to virus and cytokine inflammation, highlighting upregulation of a COVID-19 response pathway. Conclusion: COVID-19 affects endometrial gene expression despite the absence of SARS-CoV-2 particles in endometrial tissues.
Project description:BackgroundMedicines for the treatment of 2019-novel coronavirus (2019-nCoV) infections are urgently needed. However, drug screening using live 2019-nCoV requires high-level biosafety facilities, which imposes an obstacle for those institutions without such facilities or 2019-nCoV. This study aims to repurpose the clinically approved drugs for the treatment of coronavirus disease 2019 (COVID-19) in a 2019-nCoV-related coronavirus model.MethodsA 2019-nCoV-related pangolin coronavirus GX_P2V/pangolin/2017/Guangxi was described. Whether GX_P2V uses angiotensin-converting enzyme 2 (ACE2) as the cell receptor was investigated by using small interfering RNA (siRNA)-mediated silencing of ACE2. The pangolin coronavirus model was used to identify drug candidates for treating 2019-nCoV infection. Two libraries of 2406 clinically approved drugs were screened for their ability to inhibit cytopathic effects on Vero E6 cells by GX_P2V infection. The anti-viral activities and anti-viral mechanisms of potential drugs were further investigated. Viral yields of RNAs and infectious particles were quantified by quantitative real-time polymerase chain reaction (qRT-PCR) and plaque assay, respectively.ResultsThe spike protein of coronavirus GX_P2V shares 92.2% amino acid identity with that of 2019-nCoV isolate Wuhan-hu-1, and uses ACE2 as the receptor for infection just like 2019-nCoV. Three drugs, including cepharanthine (CEP), selamectin, and mefloquine hydrochloride, exhibited complete inhibition of cytopathic effects in cell culture at 10 μmol/L. CEP demonstrated the most potent inhibition of GX_P2V infection, with a concentration for 50% of maximal effect [EC50] of 0.98 μmol/L. The viral RNA yield in cells treated with 10 μmol/L CEP was 15,393-fold lower than in cells without CEP treatment ([6.48 ± 0.02] × 10vs. 1.00 ± 0.12, t = 150.38, P < 0.001) at 72 h post-infection (p.i.). Plaque assays found no production of live viruses in media containing 10 μmol/L CEP at 48 h p.i. Furthermore, we found CEP had potent anti-viral activities against both viral entry (0.46 ± 0.12, vs.1.00 ± 0.37, t = 2.42, P < 0.05) and viral replication ([6.18 ± 0.95] × 10vs. 1.00 ± 0.43, t = 3.98, P < 0.05).ConclusionsOur pangolin coronavirus GX_P2V is a workable model for 2019-nCoV research. CEP, selamectin, and mefloquine hydrochloride are potential drugs for treating 2019-nCoV infection. Our results strongly suggest that CEP is a wide-spectrum inhibitor of pan-betacoronavirus, and further study of CEP for treatment of 2019-nCoV infection is warranted.
Project description:Hosts have evolved numerous mechanisms to prevent primary viral infections. Interferon signaling is an important host defense mechanism against primary infection. Interferon gamma (IFN-γ) is a potent cytokine produced following primary varicella-zoster virus (VZV) infection. Furthermore, VZV reactivation correlates with a decline in IFN-γ-producing immune cells. Our previous results showed that pretreatment with 20 ng/ml of IFN-γ completely inhibited VZV replication in lung fibroblast MRC-5 and retinal epithelial ARPE-19, suggesting that IFN-γ-stimulated protein(s) inhibit viral replication. Our microarray analysis revealed that a small subset of interferon-stimulated genes (ISGs) was upregulated by greater than 3.5-fold at 8 h post-treatment in both ARPE-19 and MRC-5 cells compared to those of melanoma MeWo cells. The depletion of IFITM1 and IRF1 by siRNA in IFN-γ-treated cells significantly increased (from 0 to ~1x103 pfu/105 cells) VZV yields. In contrast, the depletion of a nontargeting control (siNTC) did not increase virus yield. Ectopic expression of interferon-induced transmembrane protein 1 (IFITM1) reduced the level of IE62 protein as well as intracellular VZV yield in both ARPE-19 and MeWo cells, but did not reduce the expression level of IE62 mRNA, suggesting that IFITM1 expression reduces the expression level of IE62 by post-transcriptional regulation. IFITM1 also reduced the expression levels of VZV IE62, HSV-1 ICP4, and EHV-1 IEP in ARPE-19 cells
Project description:ObjectiveIt is well established that angiogenesis is a complex and coordinated multistep process. However, there remains a lack of information about the genes that regulate individual stages of vessel formation. Here, we aimed to define the role of human interferon-induced transmembrane protein 1 (IFITM1) during blood vessel formation.Approach and resultsWe identified IFITM1 in a microarray screen for genes differentially regulated by endothelial cells (ECs) during an in vitro angiogenesis assay and found that IFITM1 expression was strongly induced as ECs sprouted and formed lumens. We showed by immunohistochemistry that human IFITM1 was expressed by stable blood vessels in multiple organs. siRNA-mediated knockdown of IFITM1 expression spared EC sprouting but completely disrupted lumen formation, in both in vitro and in an in vivo xeno-transplant model. ECs lacking IFITM1 underwent early stages of lumenogenesis (ie, intracellular vacuole formation) but failed to mature or expand lumens. Coimmunoprecipitation studies confirmed occludin as an IFITM1 binding partner in ECs, and immunocytochemistry showed a lack of occludin at endothelial tight junctions in the absence of IFITM1. Finally, time-lapse video microscopy revealed that IFITM1 is required for the formation of stable cell-cell contacts during endothelial lumen formation.ConclusionsIFITM1 is essential for the formation of functional blood vessels and stabilizes EC-EC interactions during endothelial lumen formation by regulating tight junction assembly.
Project description:We analyzed plasma levels of interferons (IFNs) and cytokines, and expression of IFN-stimulated genes in peripheral blood mononuclear cells in patients with coronavirus disease 2019 of varying disease severity. Patients hospitalized with mild disease exhibited transient type I IFN responses, while intensive care unit patients had prolonged type I IFN responses. Type II IFN responses were compromised in intensive care unit patients. Type III IFN responses were induced in the early phase of infection, even in convalescent patients. These results highlight the importance of early type I and III IFN responses in controlling coronavirus disease 2019 progression.
Project description:Recent research has associated the interferon-induced transmembrane protein 3 gene (IFITM3) with the outcomes of coronavirus disease 2019 (COVID-19), although the findings are contradictory. This study aimed to determine the relationship between IFITM3 gene rs34481144 polymorphism and clinical parameters with COVID-19 mortality. The tetra-primer amplification refractory mutation system-polymerase chain reaction assay was used to analyze IFITM3 rs34481144 polymorphism in 1,149 deceased and 1,342 recovered patients. The clinical parameters were extracted from the patients' medical records. In this study, the frequency of IFITM3 rs34481144 CT genotypes (OR 1.47, 95% CI 1.23-1.76, P < 0.0001) in both sexes was significantly higher in deceased patients than in recovered patients. Moreover, IFITM3 rs34481144 TT genotypes (OR 3.38, 95% CI 1.05-10.87, P < 0.0001) in women were significantly associated with COVID-19 mortality. The multivariable logistic regression model results indicated that mean age (P < 0.001), alkaline phosphatase (P = 0.005), alanine aminotransferase (P < 0.001), low-density lipoprotein (P < 0.001), high-density lipoprotein (P < 0.001), fasting blood glucose (P = 0.010), creatinine (P < 0.001), uric acid (P < 0.001), C-reactive protein (P = 0.004), 25-hydroxyvitamin D (P < 0.001), erythrocyte sedimentation rate (P < 0.001), and real-time PCR Ct values (P < 0.001) were linked with increased COVID-19 death rates. In conclusion, IFITM3 rs34481144 gene polymorphism was linked to the mortality of COVID-19, with the rs34481144-T allele being especially important for mortality. Further studies are needed to confirm the results of this study.