Interferon-inducible Protein Research Articles

Development of Live Vaccine Candidates for Canine Influenza H3N2 Using Naturally Truncated NS1 Gene

The NS1 influenza protein of influenza A virus is a viral nonstructural protein encoded by the NS gene segment that has multiple accessory functions during viral infection. In recent years, the major role ascribed to NS1 has been its inhibition of host immune responses, especially the limitation of both interferon (IFN) production and the antiviral effects of IFN-induced protein. We isolated an equine influenza virus with a naturally truncated NS1 gene in our previous study. In this current research, we inserted this partially truncated NS gene into the H3N2 canine influenza virus using reverse genetics to develop a live attenuated vaccine strain. To evaluate whether the developed strain is suitable as a live vaccine candidate, we compared its replication kinetics with wild-type virus in MDCK cells and specific pathogen-free eggs. Additionally, we investigated host antiviral gene expression, viral replication in the respiratory system, and associated lung tissue damage in mice experiments. To confirm the efficacy of the vaccine candidate, we evaluated the immunogenicity and protectivity of the developed vaccine strain against canine influenza H3N2, compared with a commercial inactivated vaccine. Through these experiments, it was confirmed that the naturally truncated NS1 inserted virus has sufficient potential as a live vaccine candidate, and we hopefully expect that this study would make a great contribution to the development of a live vaccine for canine influenza H3N2.

TRAIL and IP-10 dynamics in pregnant women post COVID-19 vaccination: associations with neutralizing antibody potency.

The aim of this study is to investigate changes in TNF-related apoptosis-inducing ligand (TRAIL) and gamma interferon-induced protein 10 (IP-10) after COVID-19 vaccination in pregnant women and to explore their association with neutralizing antibody (Nab) inhibition. The study evaluated 93 pregnant women who had previously received two (n=21), three (n=55) or four (n=17) doses of COVID-19 vaccine. Also we evaluated maternal blood samples that were collected during childbirth. The levels of TRAIL, IP-10 and Nab inhibition were measured using enzyme-linked immunosorbent assays (ELISA). Our study revealed four-dose group resulted in lower TRAIL levels when compared to the two-dose and three-dose groups (4.78 vs. 16.07 vs. 21.61 pg/ml, p = 0.014). The two-dose group had reduced IP-10 levels than the three-dose cohort (111.49 vs. 147.89 pg/ml, p=0.013), with no significant variation compared to the four-dose group. In addition, the four-dose group showed stronger Nab inhibition against specific strains (BA.2 and BA.5) than the three-dose group. A positive correlation was observed between TRAIL and IP-10 in the two-dose group, while this relationship was not found in other dose groups or between TRAIL/IP-10 and Nab inhibition. As the doses of the COVID-19 vaccine increase, the levels of TRAIL and IP-10 generally increase, only by the fourth dose, the group previously vaccinated with AZD1222 showed lower TRAIL but higher IP-10. Despite these changes, more doses of the vaccine consistently reinforced Nab inhibition, apparently without any relation to TRAIL and IP-10 levels. The variation may indicate the induction of immunological memory in vaccinated mothers, which justifies further research in the future.

Interferon inducible guanylate-binding protein 1 modulates the lipopolysaccharide-induced cytokines/chemokines and mitogen-activated protein kinases in macrophages.

Guanylate-binding proteins (GBPs) are a family of interferon (IFN)-inducible GTPases and play a pivotal role in the host immune response to microbial infections. These are upregulated in immune cells after recognizing the lipopolysaccharides (LPS), the major membrane component of Gram-negative bacteria. In the present study, the expression pattern of GBP1-7 was initially mapped in phorbol 12-myristate 13-acetate-differentiated human monocytes THP-1 and mouse macrophages RAW 264.7 cell lines stimulated with LPS. A time-dependent significant expression of GBP1-7 was observed in these cells. Moreover, among the various GBPs, GBP1 has emerged as a central player in regulating innate immunity and inflammation. Therefore, to study the specific role of GBP1 in LPS-induced inflammation, knockdown of the Gbp1 gene was carried out in both cells using small interfering RNA interference. Altered levels of different cytokines (interleukin [IL]-4, IL-10, IL-12β, IFN-γ, tumor necrosis factor-α), inducible nitric oxide synthase, histocompatibility 2, class II antigen A, protein kinase R, and chemokines (chemokine (C-X-C motif) ligand 9[CXCL9],CXCL10, and CXCL11) in GBP1 knockdown cells were reported compared to control cells. Interestingly, the extracellular-signal-regulated kinase 1/2 mitogen-activated protein (MAP) kinases and signal transducer and activator of transcription 1 (STAT1) transcription factor levels were considerably induced in knockdown cells compared to the control cells. However, no change in the level of phosphorylated nuclear factor-kB, c-Jun, and p38 transcription factors was observed in GBP1 knockdown cells compared to the control cells. This study concludes that GBP1 may alter the expression of cytokines, chemokines, and effector molecules mediated by MAP kinases and STAT1 transcription factors.

Genome-wide CRISPR activation screen identifies JADE3 as an antiviral activator of NF-kB–dependent IFITM3 expression

The innate immune system features a web of interacting pathways that require exquisite regulation. To identify novel nodes in this immune landscape we conducted a gain of function, genome-wide CRISPR activation screen with influenza A virus. We identified both appreciated and novel antiviral genes, including JADE3 a protein involved in directing the histone acetyltransferase HBO1 complex to modify chromatin and regulate transcription. JADE3 is both necessary and sufficient to restrict influenza A virus infection. Our results suggest a distinct function for JADE3 as expression of the closely related paralogues JADE1 and JADE2 does not confer resistance to influenza A virus infection. JADE3 is required for both constitutive and inducible expression of the well characterized antiviral gene Interferon-Induced Transmembrane Protein 3 (IFITM3). Furthermore, we find JADE3 activates the NF-kB signaling pathway, which is required for the promotion of IFITM3 expression by JADE3. Therefore, we propose JADE3 activates an antiviral genetic program involving NF-kB dependent IFITM3 expression to restrict influenza A virus infection.

The antiviral role of largemouth bass STING against iridovirus infection

Stimulator of interferon gene (STING) plays a crucial role in the innate immune response against viral and bacterial pathogens. However, its function in largemouth bass iridovirus (LMBV) infection remains uncertain. Here, a STING homolog (MsSTING) from largemouth bass (Micropterus salmoides) was cloned and characterized. MsSTING encoded a 407-amino-acid polypeptide, which shared 84.08% and 41.45% identity with golden perch (Perca flavescens) and human (Homo sapiens) homologs, respectively. MsSTING contained four transmembrane domains and a conserved C-terminal domain. The mRNA level of MsSTING was significantly increased in response to LMBV infection in vitro. Subcellular localization observation indicated that MsSTING encoded a cytoplasmic protein, which co-localized predominantly with endoplasmic reticulum (ER) and partially with mitochondria. Moreover, its accurate localization was dependent on the N-terminal transmembrane motif (TM) domains. MsSTING was able to activate interferon (IFN) response, evidenced by the activation of IFN1, IFN3 and ISRE promoters by its overexpression in vitro. Mutant analysis showed that both the N-terminal and C-terminal domain of MsSTING were essential for its activation on IFN response. In addition, overexpression of MsSTING inhibited the transcription and protein levels of viral core genes, indicating that MsSTING exerted antiviral action against LMBV. Consistently, the inhibitory effects were significantly attenuated when the N-terminal or C-terminal domains of MsSTING was deleted. Furthermore, MsSTING overexpression upregulated the transcriptions of interferon-related genes and pro-inflammatory factors, including TANK-binding kinase 1(TBK1), interferon regulatory factor 3 (IRF3), interferon regulatory factor 7 (IRF7), interferon stimulated exonuclease gene 20 (ISG20), interferon-induced transmembrane protein 1(IFITM1), interferon γ (IFN-γ), tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and interleukin 6 (IL-6). Together, MsSTING exerted antiviral action upon LMBV infection through positive regulation the innate immune response.

IFITM3 inhibits severe fever with thrombocytopenia syndrome virus entry and interacts with viral Gc protein.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne hemorrhagic fever disease with high fatality rate of 10%-20%. Vaccines or specific therapeutic measures remain lacking. Human interferon inducible transmembrane protein 3 (hIFITM3) is a broad-spectrum antiviral factor targeting viral entry. However, the antiviral activity of hIFITM3 against SFTS virus (SFTSV) and the functional mechanism of IFITM3 remains unclear. Here we demonstrate that endogenous IFITM3 provides protection against SFTSV infection and participates in the anti-SFTSV effect of type Ⅰ and Ⅲ interferons (IFNs). IFITM3 overexpression exhibits anti-SFTSV function by blocking Gn/Gc-mediated viral entry and fusion. Further studies showed that IFITM3 binds SFTSV Gc directly and its intramembrane domain (IMD) is responsible for this interaction and restriction of SFTSV entry. Mutation of two neighboring cysteines on IMD weakens IFITM3-Gc interaction and attenuates the antiviral activity of IFITM3, suggesting that IFITM3-Gc interaction may partly mediate the inhibition of SFTSV entry. Overall, our data demonstrate for the first time that hIFITM3 plays a critical role in the IFNs-mediated anti-SFTSV response, and uncover a novel mechanism of IFITM3 restriction of SFTSV infection, highlighting the potential of clinical intervention on SFTS disease.

Analysis of Chicken IFITM3 Gene Expression and Its Effect on Avian Reovirus Replication.

Interferon-inducible transmembrane protein 3 (IFITM3) is an antiviral factor that plays an important role in the host innate immune response against viruses. Previous studies have shown that IFITM3 is upregulated in various tissues and organs after avian reovirus (ARV) infection, which suggests that IFITM3 may be involved in the antiviral response after ARV infection. In this study, the chicken IFITM3 gene was cloned and analyzed bioinformatically. Then, the role of chicken IFITM3 in ARV infection was further explored. The results showed that the molecular weight of the chicken IFITM3 protein was approximately 13 kDa. This protein was found to be localized mainly in the cytoplasm, and its protein structure contained the CD225 domain. The homology analysis and phylogenetic tree analysis showed that the IFITM3 genes of different species exhibited great variation during genetic evolution, and chicken IFITM3 shared the highest homology with that of Anas platyrhynchos and displayed relatively low homology with those of birds such as Anser cygnoides and Serinus canaria. An analysis of the distribution of chicken IFITM3 in tissues and organs revealed that the IFITM3 gene was expressed at its highest level in the intestine and in large quantities in immune organs, such as the bursa of Fabricius, thymus and spleen. Further studies showed that the overexpression of IFITM3 in chicken embryo fibroblasts (DF-1) could inhibit the replication of ARV, whereas the inhibition of IFITM3 expression in DF-1 cells promoted ARV replication. In addition, chicken IFITM3 may exert negative feedback regulatory effects on the expression of TBK1, IFN-γ and IRF1 during ARV infection, and it is speculated that IFITM3 may participate in the innate immune response after ARV infection by negatively regulating the expression of TBK1, IFN-γ and IRF1. The results of this study further enrich the understanding of the role and function of chicken IFITM3 in ARV infection and provide a theoretical basis for an in-depth understanding of the antiviral mechanism of host resistance to ARV infection.

Interferon-induced protein with tetratricopeptide repeats 5 of black fruit bat (Pteropus alecto) displays a broad inhibition of RNA viruses.

Bats are natural host reservoirs and have adapted a unique innate immune system that permits them to host many viruses without exhibiting symptoms. Notably, bat interferon stimulated genes (ISGs) have been shown to play antiviral roles. Interferon induced protein with tetratricopeptide repeats 5 (IFIT5) is a well-characterised ISG in humans with antiviral activities against negative-sense RNA viruses via inhibiting viral transcription. Here, we aim to investigate if Pteropus alecto (pa) IFIT5 (paIFIT5) possess the ability to inhibit negative-sense RNA viruses. Initially, gene syntenic and comparative structural analyses of multiple animals highlighted a high level of similarity between Pteropus alecto and human IFIT5 proteins. Our results showed that paIFIT5 was significantly inducible by viral and dsRNA stimulation. Transient overexpression of paIFIT5 inhibited the replication of vesicular stomatitis virus (VSV). Using minireplicon and transcription reporter assays, we demonstrated the ability of paIFIT5 specifically to inhibit H17N10 polymerase activity. Mechanistically, we noticed that the antiviral potential of paIFIT5 against negative sense RNA viruses was retributed to its interaction with 5'ppp containing RNA. Taken together, these findings highlight the genetic and functional conservation of IFIT5 among mammals.

Role of Viral Envelope Proteins in Determining Susceptibility of Viruses to IFITM Proteins.

Interferon-induced transmembrane proteins (IFITMs) are a family of proteins which inhibit infections of various enveloped viruses. While their general mechanism of inhibition seems to be non-specific, involving the tightening of membrane structures to prevent fusion between the viral envelope and cell membrane, numerous studies have underscored the importance of viral envelope proteins in determining the susceptibility of viruses to IFITMs. Mutations in envelope proteins may lead to viral escape from direct interaction with IFITM proteins or result in indirect resistance by modifying the viral entry pathway, allowing the virus to modulate its exposure to IFITMs. In a broader context, the nature of viral envelope proteins and their interaction with IFITMs can play a crucial role in the context of adaptive immunity, leading to viral envelope proteins that are more susceptible to antibody neutralization. The precise mechanisms underlying these observations remain unclear, and further studies in this field could contribute to a better understanding of how IFITMs control viral infections.

Serum chemokine IL-8 acts as a biomarker for identifying COVID-19-associated persistent severe acute kidney injury

Objectives Persistent severe acute kidney injury (PS-AKI) is associated with poor clinical outcomes. Our study attempted to evaluate the diagnostic value of chemokines for early-stage PS-AKI prediction. Methods According to the KDIGO criteria, 115 COVID-19 patients diagnosed with stage 2/3 AKI were recruited from the intensive care unit between December 2022 and February 2023. Primary clinical outcomes included detecting PS-AKI in the first week (≥ KDIGO stage 2 ≥ 72 h). Cytometric Bead Array was used to detect patient plasma levels (interleukin-8 (IL-8), C-C chemokine ligand 5 (CCL5), chemokine (C-X-C Motif) ligand 9 (CXCL9), and interferon-inducible protein 10 (IP-10)) of chemokines within 24 h of enrollment. Results Of the 115 COVID-19 patients with stage 2/3 AKI, 27 were diagnosed with PS-AKI. Among the four measured chemokines, only the IL-8 level was significantly elevated in the PS-AKI group than in the Non-PS-AKI group. IL-8 was more effective as a biomarker while predicting PS-AKI with an area under the curve of 0.769 (0.675-0.863). This was superior to other biomarkers related to AKI, including serum creatinine. Moreover, plasma IL-8 levels of >32.2 pg/ml on admission could predict PS-AKI risk (sensitivity = 92.6%, specificity = 51.1%). Additionally, the IL-8 level was associated with total protein and IL-6 levels. Conclusion Plasma IL-8 is a promising marker for the early identification of PS-AKI among COVID-19 patients. These findings should be validated in further studies with a larger sample size.

Anterior chamber cytokine production and postoperative macular edema in patients with diabetes undergoing FLACS.

To evaluate the effect of femtosecond laser-assisted cataract surgery (FLACS) and manual cataract surgery (MCS) on proinflammatory cytokine expression in patients with diabetes vs nondiabetic patients. Outpatient surgical center in Vaughan, Ontario, Canada. Prospective cohort study. Patients with diabetes and nondiabetic patients undergoing noncomplicated MCS or FLACS were assigned into 4 cohorts: MCS nondiabetic (n = 30), FLACS nondiabetic (n = 42), MCS diabetic (n = 40), and FLACS diabetic (n = 40). Aqueous humor inflammatory mediator concentrations were evaluated at MCS onset and after femtosecond laser treatment. The presence of cystoid macular edema, anterior chamber (AC) inflammation, central retinal thickness, macular volume, and retinal microvascular changes (through optical coherence tomography angiography) were evaluated preoperatively and on postoperative day 1, week 1, month 1 (POM1), and month 3 (POM3). Patients with diabetes receiving FLACS had a higher concentration of interleukin (IL)-7, IL-13, and interferon-induced protein-10 than MCS diabetic patients; they also demonstrated higher levels of vascular endothelial growth factor and lower levels of interferon (IFN)-γ, granulocyte colony-stimulating factor, and IFN-α2 compared with MCS nondiabetic patients. Macular volume appeared to be significantly higher in MCS diabetic vs MCS non-diabetic patients at POM1 and between FLACS diabetic vs FLACS nondiabetic patients at POM3. There were no other significant differences between the cohorts for any parameter. FLACS use in patients with diabetes demonstrated some differences in AC cytokine expression compared with non-diabetic FLACS or diabetic patients undergoing MCS; however, there was no increase in clinical inflammatory biomarkers. FLACS seems to be a safe technique to use in patients with diabetes.

Epstein-Barr virus lytic gene BNRF1 promotes B-cell lymphomagenesis via IFI27 upregulation.

Epstein-Barr virus (EBV) is a ubiquitous human lymphotropic herpesvirus that is causally associated with several malignancies. In addition to latent factors, lytic replication contributes to cancer development. In this study, we examined whether the lytic gene BNRF1, which is conserved among gamma-herpesviruses, has an important role in lymphomagenesis. We found that lymphoblastoid cell lines (LCLs) established by BNRF1-knockout EBV exhibited remarkably lower pathogenicity in a mice xenograft model than LCLs produced by wild-type EBV (LCLs-WT). RNA-seq analyses revealed that BNRF1 elicited the expression of interferon-inducible protein 27 (IFI27), which promotes cell proliferation. IFI27 knockdown in LCLs-WT resulted in excessive production of reactive oxygen species, leading to cell death and significantly decreased their pathogenicity in vivo. We also confirmed that IFI27 was upregulated during primary infection in B-cells. Our findings revealed that BNRF1 promoted robust proliferation of the B-cells that were transformed by EBV latent infection via IFI27 upregulation both in vitro and in vivo.

Interferon-Induced Transmembrane Protein 3 (IFITM3) gene Polymorphisms in COVID-19 patients in Assiut University Hospitals

Interferon-Induced Transmembrane Protein 3 (IFITM3) gene Polymorphisms in COVID-19 patients in Assiut University Hospitals

High throughput functional profiling of genes at intraocular pressure loci reveals distinct networks for glaucoma.

Primary open angle glaucoma (POAG) is a leading cause of blindness globally. Characterized by progressive retinal ganglion cell degeneration, the precise pathogenesis remains unknown. Genome-wide association studies (GWAS) have uncovered many genetic variants associated with elevated intraocular pressure (IOP), one of the key risk factors for POAG. We aimed to identify genetic and morphological variation that can be attributed to trabecular meshwork cell (TMC) dysfunction and raised IOP in POAG. 62 genes across 55 loci were knocked-out in a primary human TMC line. Each knockout group, including five non-targeting control groups, underwent single-cell RNA-sequencing (scRNA-seq) for differentially-expressed gene (DEG) analysis. Multiplexed fluorescence coupled with CellProfiler image analysis allowed for single-cell morphological profiling. Many gene knockouts invoked DEGs relating to matrix metalloproteinases and interferon-induced proteins. We have prioritized genes at four loci of interest to identify gene knockouts that may contribute to the pathogenesis of POAG, including ANGPTL2, LMX1B, CAV1, and KREMEN1. Three genetic networks of gene knockouts with similar transcriptomic profiles were identified, suggesting a synergistic function in trabecular meshwork cell physiology. TEK knockout caused significant upregulation of nuclear granularity on morphological analysis, while knockout of TRIOBP, TMCO1 and PLEKHA7 increased granularity and intensity of actin and the cell-membrane. High-throughput analysis of cellular structure and function through multiplex fluorescent single-cell analysis and scRNA-seq assays enabled the direct study of genetic perturbations at the single-cell resolution. This work provides a framework for investigating the role of genes in the pathogenesis of glaucoma and heterogenous diseases with a strong genetic basis.

IFIT3 accelerates the progression of head and neck squamous cell carcinoma by targeting PD-L1 to activate PI3K/AKT signaling pathway

BackgroundEmerging evidence has shown interferon-induced protein with tetratricopeptide repeats 3 (IFIT3) may be predicted to be a candidate oncogene and involved in the onset and progression of cancer, but IFIT3’s potential role in cancer, particularly in head and neck squamous cell carcinoma (HNSC), is not well recognized. This study aims to reveal the role of IFIT3 in HNSC and the underlying molecular mechanism.MethodsBioinformatics analysis, immunohistochemical staining, RT-PCR, and Western blotting analysis were used to detect IFIT3 expression in HNSC. CCK-8 assays, colony formation assays, wound-healing assays, transwell assays, and sphere formation were used to explore proliferative, migratory, and invasive activities and cancer stemness of HNSC cells after IFIT3 knockdown and over-expressed. The alterations of EMT markers and PI3K/AKT pathway were detected by Western blotting. Animal studies were performed to analyze the effect of IFIT3 on tumor growth and metastasis of HNSC in vivo.ResultsIn this study, we observed that IFIT3 was highly expressed in HNSC, and its higher expression contributed to poorer survival of patients with clinical stage IV or grade 3. Function assay indicated that IFIT3 promoted malignant behaviors in vitro, as well as tumor growth and lung metastasis in vivo. Meanwhile, PD-L1 knockdown or over-expressed reversed cancer cell stemness, migration, invasion, and PI3K/AKT signaling pathway which were regulated by IFIT3.ConclusionsOur results reveal that IFIT3 promotes EMT and cancer stemness by targeting PD-L1 to activate PI3K/AKT signaling pathway in HNSC, and targeting IFIT3 may be a novel strategy for the treatment of patients with HNSC.

CEACAM6 and IFITM3 as potential biomarkers for pelareorep in pancreatic adenocarcinoma (PDAC).

684 Background: Pelareorep (P) is a proprietary formulation of live, replication-competent, naturally occurring Reovirus Type 3 Dearing strain. We previously performed a phase II trial of P with carboplatin (C) and paclitaxel (Pxl) vs C and Pxl alone in metastatic PDAC (NCT01280058). Although P did not improve progression-free survival compared to C and Pxl alone, some exceptional durable responses were seen in the P arm. Low levels of carcinoembryonic antigen cell adhesion molecule 6 (CEACAM6) mRNA expression were associated with prolonged PFS in P-treated pts (p=0.05) and there was a 3.3 times higher fold change in Interferon-inducible transmembrane protein 3 (IFITM3) expression in the pts doing poorly versus responders (nominal p<0.05) in P arm. Here we investigate mechanisms of resistance to P infection mediated through CEACAM6 and IFITM3 in a panel of pancreatic ductal adenocarcinoma cell lines. Methods: Prior studies noted CEACAM6 and IFITM3 may restrict cell entry of certain enveloped viruses. CEACAM6 and IFITM3 protein levels were measured in PDAC cell lines using Western blot. Flow cytometry was used to assess P infectivity. We have generated multiple knockdowns of CEACAM6 and IFITM3 in PDAC cell lines to determine changes in P infectivity and other inflammatory signalling pathways. Live cell imaging was used to assess cell viability. Results: Basal expression of CEACAM6 was measured in a panel of 4 PDAC cells (PANC10.5, HPAFII, BxPC3, CFPAC1). Panc10.05 had low basal expression nor could expression be induced by 24hr P infection. All other cell lines showed moderate to high basal expression that was inducible. P infectivity at 24hrs was significantly higher in Panc10.05 cells compared to high CEACAM6 expressing cell lines. There was varying basal expression of IFITM3, however all cell lines showed IFITM3 induction when exposed to P. Of the 3 cell lines that also expressed high levels of CEACAM6 (HPAFII, CFPAC1, BxPC3), low basal expression of IFITM3 was strongly associated with increased sensitivity to P infection and decreased viability at 72hrs, which could be induced by knockdown of IFITM3 in high expressing cell lines. Neither C or Pxl altered levels of CEACAM6 or IFITM3 in any of the four cell lines. Conclusions: High CEACAM6 and IFITM3 play a role in P viral infectivity across multiple pancreatic cell lines, confirming results obtained in translational datasets. Further analysis is ongoing to elucidate mechanism and identify pathways to alter expression of CEACAM6 and IFITM3 and enhance P infectivity in future trials.

IFITM3 promotes glioblastoma stem cell-mediated angiogenesis via regulating JAK/STAT3/bFGF signaling pathway

Interferon-induced transmembrane protein 3 (IFITM3) has been previously verified to be an endosomal protein that prevents viral infection. Recent findings suggested IFITM3 as a key factor in tumor invasion and progression. To clarify the role and molecular mechanism of IFITM3 in Glioblastoma multiforme (GBM) progression, we investigated the expression of IFITM3 in glioma datasets culled from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA). Primary GBM stem cells (GSCs) were cultured and identified in vitro. Loss-of-function and gain-of-function experiments were established by using shRNAs and lentiviral vectors targeting IFITM3. Co-culture system of GSCs and vascular endothelial cells was constructed in a Transwell chamber. Tube formation and spheroid-based angiogenesis assays were performed to determine the angiogenic capacity of endothelial cells. Results revealed that IFITM3 is elevated in GBM samples and predictive of adverse outcome. Mechanistically, GSCs-derived IFITM3 causes activation of Jak2/STAT3 signaling and leads to robust secretion of bFGF into tumor environment, which eventually results in enhanced angiogenesis. Taken together, these evidence indicated IFITM3 as an essential factor in GBM angiogenesis. Our findings provide a new insight into mechanism by which IFITM3 modulates GBM angiogenesis.

ETV7 promotes colorectal cancer progression through upregulation of IFIT3

Members of the E26 transformation-specific (ETS) variant transcription factor family act as either tumor suppressors or oncogenic factors in numerous types of cancer. ETS variant transcription factor 7 (ETV7) participates in the development of malignant tumors, whereas its involvement in colorectal cancer (CRC) is less clear. In this study, The Cancer Genome Atlas (TCGA) and immunochemistry staining were applied to check the clinical relevance of ETV7 and interferon-induced protein with tetratricopeptide repeats 3 (IFIT3) in CRC patients. Overexpression and knockdown of ETV7 and IFIT3 were conducted by transfecting the cells with pCDNA3.1 plasmids and siRNAs, respectively. Western blotting was used to detect the protein expression of ETV7 in CRC cells. Cell Counting Kit-8, cell colony formation, and Transwell assays, as well as flow cytometry, were used to evaluate the proliferation, migration, cell cycle, and apoptosis of CRC cells. Furthermore, western blotting, RT-qPCR, and luciferase assay were used to explore the regulation of ETV7 on IFIT3. Rescue assay was used to investigate the significance of ETV7/IFIT3 axis on CRC progression. We found that ETV7 was upregulated in CRC tissues and cells. Overexpression of ETV7 stimulated the proliferation, migration, and cell cycle amplification, and reduced the apoptosis of CRC cells. Downregulation of ETV7 exerted the opposite effect on CRC cell progression. Moreover, we demonstrated that ETV7 stimulated the transcription activity, the mRNA and protein expression of IFIT3 in CRC cells. There was a positive correlation between ETV7 and IFIT3 in CRC patients. IFIT3 knockdown reversed the promotive effect exerted by overexpression of ETV7 on the amplification and migration of CRC cells. By contrast, overexpression of IFIT3 blocked the inhibitory effect of ETV7-targeting siRNA. In summary, ETV7 induces progression of CRC by activating the transcriptional expression of IFIT3. The EVT7/IFIT3 axis may be a novel target for CRC therapy.

Evaluation of long non-coding RNAs EGOT, NRAV, NRIR and mRNAs ISG15 and IFITM3 expressions in COVID-19 patients

Individuals with Coronavirus Disease 2019 (COVID-19) may show no symptoms to moderate or severe complications. This variation may be due to differences in the strength of the immune response, including a delayed interferon (IFN) response in asymptomatic patients and higher IFN levels in severe patients. Some long non-coding RNAs (lncRNAs), as regulators of the IFN pathway, may contribute to the emergence of different COVID-19 symptoms. This study aimed to comparatively investigate the relationship between lncRNAs (eosinophil granule ontogeny transcript (EGOT), negative regulator of antiviral response (NRAV), and negative regulator of interferon response (NRIR)), alongside interferon-stimulated genes (ISGs) like ISG-15 and interferon-induced transmembrane protein 3 (IFITM3) in COVID-19 patients with asymptomatic, moderate, and severe symptoms. Buffy coat samples were collected from 17 asymptomatic, 23 moderate, 22 severe patients, and 44 healthy controls. Quantitative real-time PCR was utilized to determine the expression levels. In a comparison between COVID-19 patients and healthy individuals, higher expression levels of EGOT and NRAV were observed in severe and moderate patients. NRIR expression was increased across all patient groups. Meanwhile, ISG15 expression decreased in all patient groups, and the moderate group showed a significant decrease in IFITM3 expression. Comparing COVID-19 patient groups, EGOT expression was significantly higher in moderate COVID-19 patients compared to asymptomatic patients. NRAV was higher in moderate and severe patients compared to asymptomatic. NRIR levels did not differ significantly between the COVID-19 patient groups. ISG15 was higher in moderate and severe patients compared to asymptomatic. IFITM3 expression was significantly higher in severe patients compared to the moderate group. In severe COVID-19 patients, EGOT expression was positively correlated with NRAV levels. EGOT and NRAV showed a significant positive correlation in asymptomatic patients, and both were positively correlated with IFITM3 expression. This study suggests that EGOT, NRAV, NRIR, ISG15, and IFITM3 may serve as diagnostic biomarkers for COVID-19. The lncRNA NRAV may be a good biomarker in a prognostic panel between asymptomatic and severe patients in combination with other high-sensitivity biomarkers. EGOT, NRAV, and ISG15 could also be considered as specific biomarkers in a prognostic panel comparing asymptomatic and moderate patients with other high-sensitivity biomarkers.

A Knockout of the IFITM3 Gene Increases the Sensitivity of WI-38 VA13 Cells to the Influenza A Virus.

One of the ways to regulate the sensitivity of human cells to the influenza virus is to knock out genes of the innate immune response. Promising targets for the knockout are genes of the interferon-inducible transmembrane protein (IFITM) family, in particular the IFITM3 gene, whose product limits the entry of a virus into the cell by blocking the fusion of the viral and endosomal membranes. In this study, by means of genome-editing system CRISPR/Cas9, monoclonal cell lines with an IFITM3 knockout were obtained based on WI-38 VA13 cells (human origin). It was found that such cell lines are more sensitive to infection by influenza A viruses of various subtypes. Nevertheless, this feature is not accompanied by an increased titer of newly formed viral particles in a culture medium.