Interferon-induced Transmembrane Protein Research Articles

Discovery and Characterization of IFITM S-Palmitoylation.

Interferon-induced transmembrane proteins (IFITM1, 2 and 3) are important host antiviral defense factors. They are active against viruses like the influenza A virus (IAV), dengue virus (DENV), Ebola virus (EBOV), Zika virus (ZIKV) and severe acute respiratory syndrome coronavirus (SARS-CoV). In this review, we focus on IFITM3 S-palmitoylation, a reversible lipid modification, and describe its role in modulating IFITM3 antiviral activity. Our laboratory discovered S-palmitoylation of IFITMs using chemical proteomics and demonstrated the importance of highly conserved fatty acid-modified Cys residues in IFITM3 antiviral activity. Further studies showed that site-specific S-palmitoylation at Cys72 is important for IFITM3 trafficking to restricted viruses (IAV and EBOV) and membrane-sterol interactions. Thus, site-specific lipid modification of IFITM3 directly regulates its antiviral activity, cellular trafficking, and membrane-lipid interactions.

The Epigenetic Controller Lysine-Specific Demethylase 1 (LSD1) Regulates the Outcome of Hepatitis C Viral Infection.

Hepatitis C virus (HCV) alters gene expression epigenetically to rearrange the cellular microenvironment in a beneficial way for its life cycle. The host epigenetic changes induced by HCV lead to metabolic dysfunction and malignant transformation. Lysine-specific demethylase 1 (LSD1) is an epigenetic controller of critical cellular functions that are essential for HCV propagation. We investigated the putative role of LSD1 in the establishment of HCV infection using genetic engineering and pharmacological inhibition to alter endogenous LSD1 levels. We demonstrated for the first time that HCV replication was inhibited in LSD1-overexpressing cells, while specific HCV proteins differentially fine-tuned endogenous LSD1 expression levels. Electroporation of the full-length HCV genome and subgenomic replicons in LSD1 overexpression enhanced translation and partially restored HCV replication, suggesting that HCV might be inhibited by LSD1 during the early steps of infection. Conversely, the inhibition of LSD1, followed by HCV infection in vitro, increased viral replication. LSD1 was shown to participate in an intriguing antiviral mechanism, where it activates endolysosomal interferon-induced transmembrane protein 3 (IFITM3) via demethylation, leading endocytosed HCV virions to degradation. Our study proposes that HCV-mediated LSD1 oscillations over countless viral life cycles throughout chronic HCV infection may promote epigenetic changes related to HCV-induced hepatocarcinogenesis.

CAR Gene Delivery by T-cell Targeted Lentiviral Vectors is Enhanced by Rapamycin Induced Reduction of Antiviral Mechanisms.

Lentiviral vectors (LV) have become the dominant tool for stable gene transfer into lymphocytes including chimeric antigen receptor (CAR) gene delivery to T cells, a major breakthrough in cancer therapy. Yet, room for improvement remains, especially for the latest LV generations delivering genes selectively into T cell subtypes, a key requirement for in vivo CAR T cell generation. Toward improving gene transfer rates with these vectors, whole transcriptome analyses on human T lymphocytes are conducted after exposure to CAR-encoding conventional vectors (VSV-LV) and vectors targeted to CD8+ (CD8-LV) or CD4+ T cells (CD4-LV). Genes related to quiescence and antiviral restriction are found to be upregulated in CAR-negative cells exposed to all types of LVs. Down-modulation of various antiviral restriction factors, including the interferon-induced transmembrane proteins (IFITMs) is achieved with rapamycin as verified by mass spectrometry (LC-MS). Strikingly, rapamycin enhances transduction by up to 7-fold for CD8-LV and CD4-LV without compromising CAR T cell activities but does not improve VSV-LV. When administered to humanized mice, CD8-LV results in higher rates of green fluorescent protein (GFP) gene delivery. Also in vivo CAR T cell generation is improved in kinetics and tumor control, however to a moderate extent, leaving room for improvement by optimizing the rapamycin administration schedule. The data favor multi-omics approaches for improvements in gene delivery.

Oncostatin M Induces IFITM1 Expression to Inhibit Hepatitis B Virus Replication Via JAK-STAT Signaling

Functional cure is achieved by a limited number of patients with chronic hepatitis B (CHB) after nucleotide analogue(s) and interferon treatment. It is urgent to develop therapies that can help a larger proportion of patients achieve functional cure. The present study was designed to explore the anti-hepatitis B virus (HBV) potency of interleukin-6 family cytokines and to characterize the underlying mechanisms of the cytokine displaying the highest anti-HBV potency. HBV-infected cells were used to screened the anti-HBV potency of interleukin-6 family cytokines. The concentration of oncostatin M (OSM) in patients with chronic HBV infection was examined by enzyme-linked immunosorbent assay. The underlying mechanism of OSM anti-HBV was explored through RNA-seq. C57BL/6 mice injected with rAAV8-1.3HBV were used to explore the suppression effect of OSM on HBV invivo. OSM is the most effective of the interleukin-6 family cytokines for suppression of HBV replication (percentage of average inhibition: hepatitis B surface antigen, 34.44%; hepatitis B e antigen, 32.52%; HBV DNA, 61.57%). Hepatitis B e antigen-positive CHB patients with high OSM levels had lower hepatitis B surface antigen and hepatitis B e antigen than those with low levels. OSM activated JAK-STAT signaling pathway promoting the formation of STAT1-IRF9 transcription factor complex. Following this, OSM increased the expression of various genes with known functions in innate and adaptive immunity, which was higher expression in patients with CHB in immune clearance phase than in immune tolerance phase (data from GEO: GSE65359). Interferon-induced transmembrane protein 1, one of the most differentially expressed genes, was identified as an HBV restriction factor involved in OSM-mediated anti-HBV effect. Invivo, we also found OSM significantly inhibited HBV replication and induced expression of antiviral effector interferon-induced transmembrane protein1. Our study shows that OSM remodels the immune response against HBV and exerts potent anti-HBV activity, supporting its further development as a potential therapy for treating CHB.

OC 78.3 Interferon-Induced Transmembrane Protein 3 in Platelets Mediates Granule Secretion, Thrombosis, and Pathophysiological Outcomes in Sepsis

OC 78.3 Interferon-Induced Transmembrane Protein 3 in Platelets Mediates Granule Secretion, Thrombosis, and Pathophysiological Outcomes in Sepsis

Avian sarcoma/leukosis virus (RCAS)-mediated over-expression of IFITM3 protects chicks from highly pathogenic avian influenza virus subtype H5N1

Broad-spectrum antiviral activities of interferon-induced transmembrane proteins (IFITMs) are primarily attributed to in vitro inhibition of viral entry. Here, we used an avian sarcoma-leukosis virus (RCAS)-based gene transfer system and successfully generated chicks that constitutively express chicken IFITM3 (chIFITM3). The chIFITM3-overexpressing chicks showed significant protection and disease tolerance against highly pathogenic avian influenza virus (HPAIV) H5N1 (Clade 2.2.1.2). The chicks, overexpressing chIFITM3, also showed delayed onset of clinical symptoms, reduced viral shedding, and alleviated histopathologic alterations compared to control and challenged chicks. These findings highlight that overexpression of chIFITM3 provide a substantial defense against zoonotic H5N1 in vivo.

A Proteomics-Based Approach Identifies the NEDD4 Adaptor NDFIP2 as an Important Regulator of Ifitm3 Levels.

IFITMs are a family of highly related interferon-induced transmembrane proteins that interfere with the processes of fusion between viral and cellular membranes and are thus endowed with broad antiviral properties. A number of studies have shown how the antiviral potency of IFITMs is highly dependent on their steady-state levels, their intracellular distribution and a complex pattern of post-translational modifications, parameters that are overall tributary of a number of cellular partners. In an effort to identify additional protein partners involved in the biology of IFITMs, we devised a proteomics-based approach based on the piggyback incorporation of IFITM3 partners into extracellular vesicles. MS analysis of the proteome of vesicles bearing or not bearing IFITM3 identified the NDFIP2 protein adaptor protein as an important regulator of IFITM3 levels. NDFIP2 is a membrane-anchored adaptor protein of the E3 ubiquitin ligases of the NEDD4 family that have already been found to be involved in IFITM3 regulation. We show here that NDFIP2 acts as a recruitment factor for both IFITM3 and NEDD4 and mediates their distribution in lysosomal vesicles. The genetic inactivation and overexpression of NDFIP2 drive, respectively, lower and higher levels of IFITM3 accumulation in the cell, overall suggesting that NDFIP2 locally competes with IFITM3 for NEDD4 binding. Given that NDFIP2 is itself tightly regulated and highly responsive to external cues, our study sheds light on a novel and likely dynamic layer of regulation of IFITM3.

MicroRNA-363-3p inhibits colorectal cancer progression by targeting interferon-induced transmembrane protein 1.

The molecular mechanisms of colorectal cancer development and progression are far from being elucidated. To investigate the role of microRNA-363-3p (miR-363-3p) in the progression of colorectal cancer. Real-time polymerase chain reaction was performed to detect miRNA expression in human colorectal cancer tissues and paired normal colorectal tissues. PITA 6 was utilized to predict the targets of miR-363-3p. Dual-luciferase reporter system was used to validate the target of miR-363-3p. Plate colony formation assay and wound-healing assay were performed to evaluate cancer cells' clonogenic survival ability and migration ability, respectively. Cell proliferation was examined by cell counting kit-8 assay. Immunohistochemical staining was used to determine the expression level of interferon-induced transmembrane protein 1 (IFITM1) in colorectal cancer tissues and adjacent tissues. The TCGA and GTEx databases were used to compare the expression levels of IFITM1 mRNA in colorectal cancer tissues and normal colorectal tissues and analyze the correlation between the expression levels of IFITM1 mRNA and overall survival and disease-free survival of patients. A colorectal cancer cell line with a deficiency of IFITM1 was constructed, and the regulation effect of IFITM1 on the clonogenic growth of colorectal cancer cells was clarified. MiR-363-3p was decreased in colorectal cancer tissues compared to normal colorectal tissues. IFITM1 was characterized as a direct target of miR-363-3p. Overexpression of miR-363-3p led to decreased clonogenic survival, proliferation, and migration of colorectal cancer cells, which could be reversed by forced IFITM1 expression. MiR-363-3p can constrain clonogenic survival, proliferation, and migration of colorectal cancer cells via targeting IFITM1.

The significance of IFITM3 polymorphism in COVID-19 asymptomatic and ICU admission Kurdish patients

BackgroundThe Coronavirus Disease 2019 (COVID-19) is a global pandemic that exhibits a wide range of clinical symptoms, from asymptomatic to critically ill infections that require admission to an intensive care unit (ICU). Interferon-induced transmembrane protein 3 (IFITM3) prevents the viral envelope fusion with the cell membrane, hence playing a crucial role in the immune response. The association between single nucleotide polymorphisms (SNPs) in the IFITM3 gene and the severity of COVID-19 is controversial among various ethnic groups. MethodsSeven IFITM3 SNPs were genotyped based on DNA sequencing to investigate the association between these variants and asymptomatic and ICU-admitted COVID-19 patients of the Kurdish nation. ResultsThe present study found a significant association between rs12252 and the clinical outcome of COVID-19 (chi2 = 14.83, P = 0.00). The dominant, AA genotype model was significantly associated with a 5.212-fold increased risk of asymptomatic disease (P = 0.000, OR = 5.212). Patients with the GTA haplotypes rs12252, rs34481144, rs7478728 were shown to have a 3.9-fold increased risk of being admitted to the ICU (P = 0.003, OR = 3.9). ConclusionThis study demonstrated that the rs12252 AA genotype is probably associated with asymptomatic COVID-19. In addition, the patients having haplotypes of minor alleles rs12252, rs34481144, and rs7478728 may be associated to COVID-19 ICU admission.

Increased expression of SCARF genes favoring SARS-CoV-2 infection in key target organs in CKD.

Chronic kidney disease (CKD), especially diabetic CKD, is the condition that most increases the risk of lethal coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the underlying molecular mechanisms are unclear. SARS-CoV-2 and coronavirus-associated receptors and factors (SCARFs) regulate coronavirus cell entry and/or replication. We hypothesized that CKD may alter the expression of SCARF genes. A literature search identified 34 SCARF genes of which we selected 21 involved in interactions between SARS-CoV/SARS-CoV-2 and host cells, and assessed their mRNA expression in target tissues of COVID-19 (kidneys, lungs, aorta and heart) in mice with adenine-induced CKD. Twenty genes were differentially expressed in at least one organ in mice with CKD. For 15 genes, the differential expression would be expected to favor SARS-CoV-2 infection and/or severity. Of these 15 genes, 13 were differentially expressed in the kidney and 8 were validated in human CKD kidney transcriptomics datasets, including those for the most common cause of CKD, diabetic nephropathy. Two genes reported to protect from SARS-CoV-2 were downregulated in at least two non-kidney target organs: Ifitm3 encoding interferon-induced transmembrane protein 3 (IFITM3) in lung and Ly6e encoding lymphocyte antigen 6 family member 6 (LY6E) in aorta. CKD, including diabetic CKD, is associated with the differential expression of multiple SCARF genes in target organs of COVID-19, some of which may sensitize to SARS-CoV-2 infection. This information may facilitate developing therapeutic strategies aimed at decreasing COVID-19 severity in patients with CKD.

Hippocampal Inflammation and Gene Expression Changes in Peripheral Lipopolysaccharide Challenged Mice Showing Sickness and Anxiety-Like Behaviors.

Neuroinflammation is often associated with the development of depressive and anxiety disorders. The hippocampus is one of the brain regions affected by inflammation that is associated with these symptoms. However, the mechanism of hippocampal inflammation-induced emotional behavior remains unknown. The aim of this study was to clarify temporal changes in the neuroinflammatory responses in the hippocampus and the response of dentate gyrus (DG) neurons using peripheral lipopolysaccharide (LPS)-challenged mice. LPS administration induced anxiety-like activity in the elevated plus maze test and social interaction test after 24 h, at which time the mice had recovered from sickness behavior. We examined the hippocampal inflammation-related gene expression changes over time. The expression of interleukin-1β (Il1b) and tumor necrosis factor α (Tnfa) was rapidly enhanced and sustained until 24 h after LPS administration, whereas the expression of Il6 was transiently induced at approx. 6 h. IL-6-dependent downstream signaling of transducer and activator of transcription 3 (STAT3) was also activated approx. 3-6 h after LPS treatment. The expression of innate immune genes including interferon-induced transmembrane proteins such as interferon-induced transmembrane protein 1 (Ifitm1) and Ifitm3 and complement factors such as C1qa and C1qb started to increase approx. 6 h and showed sustained or further increase at 24 h. We also examined changes in the expression of several maturation markers in the DG and found that LPS enhanced the expression of calbindin 1 (Calb1), tryptophan-2,3-dioxigenase 2 (Tdo2), Il1rl, and neurotrophin-3 (Ntf3) at 24 h after LPS treatment. Collectively, these results demonstrate temporal changes of inflammation and gene expression in the hippocampus in LPS-induced sickness and anxiety-like behaviors.

The novel role of IFITM1-3 in myogenic differentiation of C2C12 cells.

Interferon-induced transmembrane proteins (IFITMs 1, 2, and 3) play a critical role in preventing pathogen infection in vertebrates. They are also involved in the occurrence and prognosis of cancer. Myogenesis is a complex process regulated by several factors. This study disclosed that Ifitm1-3 were upregulated in the process of myogenic differentiation of C2C12 myoblasts on days 3, 5, and 7. This positively correlated with the expression of differentiation factors MyoD, myogenin, Mrf5, and desmin. Furthermore, knockdown of Ifitm1-3 by their individual siRNAs inhibited myogenesis of C2C12 myoblasts, with relative downregulation of MyoD, myogenin, Mrf5, and desmin. Subsequently, myotube formation and fusion percentage decreased. Co-immunoprecipitation combined with LC-MS/MS analysis uncovered the interaction proteins of IFITM1 and IFITM3 in C2C12 myoblasts. A total of 84 overlapped interaction proteins of IFITM1 and IFITM3 were identified, and one of the clusters was engaged in cytoskeletal and sarcomere proteins, including desmin, myosin, actin, vimentin, nestin, ankycorbin, and nucleolin. Hence, we hypothesize that these interacting proteins may function as scaffolds for IFITM1-3, possibly through the interaction protein desmin to initiate further interaction with other proteins to participate in myogenesis; however, the molecular mechanisms remain unclear. Our study may contribute to the development of novel therapeutics for myopathic diseases.

VP24 matrix proteins of eight filoviruses downregulate innate immune response by inhibiting the interferon-induced pathway.

Filoviruses encode viral protein 24 (VP24) which effectively inhibit the innate immune responses in infected cells. Here we systematically analysed the effects of nine mammalian filovirus VP24 proteins on interferon (IFN)-induced immune response. We transiently expressed Ebola, Bombali, Bundibugyo, Reston, Sudan and Taï Forest ebolavirus (EBOV, BOMV, BDBV, RESTV, SUDV, TAFV, respectively), Lloviu virus (LLOV), Mengla dianlovirus (MLAV) and Marburgvirus (MARV) VP24 proteins and analysed their ability to inhibit IFN-α-induced activation of myxovirus resistance protein 1 (MxA) and interferon-induced transmembrane protein 3 (IFITM3) promoters. In addition, we analysed the expression of endogenous MxA protein in filovirus VP24-expressing cells. Eight filovirus VP24 proteins, including the VP24s of the recently discovered MLAV, BOMV and LLOV, inhibited IFN-induced MxA and IFITM3 promoter activation. MARV VP24 was the only protein with no inhibitory effect on the activation of either promoter. Endogenous MxA protein expression was impaired in cells transiently expressing VP24s with the exception of MARV VP24. We mutated nuclear localization signal (NLS) of two highly pathogenic filoviruses (EBOV and SUDV) and two putatively non-pathogenic filoviruses (BOMV and RESTV), and showed that the inhibitory effect on IFN-induced expression of MxA was dependent on functional cluster 3 of VP24 nuclear localization signal. Our findings suggest that filovirus VP24 proteins are both genetically and functionally conserved, and that VP24 proteins of most filovirus species are capable of inhibiting IFN-induced antiviral gene expression thereby efficiently downregulating the host innate immune responses.

The truncated IFITM3 facilitates the humoral immune response in inactivated influenza vaccine-vaccinated mice via interaction with CD81

ABSTRACT A single-nucleotide polymorphism (SNP) rs12252-C of interferon-induced transmembrane protein 3 (IFITM3), resulting in a truncated IFITM3 protein lacking 21 N-terminus amino acids, is associated with severe influenza infection in the Chinese population. However, the effect of IFITM3 rs12252-C on influenza vaccination and the underlying mechanism is poorly understood. Here, we constructed a mouse model with a deletion of 21 amino acids at the N-terminus (NΔ21) of IFITM3 and then compared the antibody response between Quadrivalent influenza vaccine (QIV) immunized wild-type (WT) mice and NΔ21 mice. Significantly higher levels of haemagglutination inhibition (HI) titre, neutralizing antibodies (NAb), and immunoglobulin G (IgG) to H1N1, H3N2, B/Victory, and B/Yamagata viruses were observed in NΔ21 mice compared to WT mice. Correspondingly, the numbers of splenic germinal centre (GC) B cells, plasma cells, memory B cells, QIV-specific IgG+ antibody-secreting cells (ASC), and T follicular helper cells (TFH) in NΔ21 mice were higher compared with WT mice. Moreover, the 21-amino-acid deletion caused IFITM3 translocation from the endocytosis compartment to the periphery of cells, which also prevented the degradation of a co-stimulatory molecule of B cell receptor (BCR) CD81 on the cell surface. More importantly, a more interaction was observed between NΔ21 protein and CD81 compared to the interaction between IFITM3 and CD81. Overall, our study revealed a potential mechanism of NΔ21 protein enhancing humoral immune response by relocation to prevent the degradation of CD81, providing insight into SNP affecting influenza vaccination.

Interferon-induced transmembrane protein 3 in the hippocampus: a potential novel target for the therapeutic effects of recombinant human brain natriuretic peptide on sepsis-associated encephalopathy.

This study aims to explore whether interferon-induced transmembrane protein 3 (IFITM3) is involved in recombinant human brain natriuretic peptide (rhBNP)-mediated effects on sepsis-induced cognitive dysfunction in mice. The cellular localization and expression level of IFITM3 in the hippocampus were detected. The IFITM3 overexpression was achieved using an intracranial stereotactic system to inject an adeno-associated virus into the hippocampal CA1 region of mice. Field experiments, an elevated plus maze, and conditioned fear memory tests assessed the cognitive impairment in rhBNP-treated septic mice. Finally, in the hippocampus of septic mice, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining and Immunoblot were used to detect changes in the protein expression of cleaved Caspase-8 and cleaved Caspase-3 in apoptosis-related pathways, and toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB) p65 in inflammatory pathways. Fourteen days after cecal ligation and puncture (CLP) surgery, IFITM3 localized in the plasma membrane and cytoplasm of the astrocytes in the hippocampus of septic mice, partially attached to the perivascular and neuronal surfaces, but not expressed in the microglia. The expression of IFITM3 was increased in the astrocytes and neurons in the hippocampus of septic mice, which was selectively inhibited by the administration of rhBNP. Overexpression of IFITM3 resulted in elevated anxiety levels and long-term learning and memory dysfunction, completely abolished the therapeutic effect of rhBNP on cognitive impairment in septic mice, and induced an increase in the number of neuronal apoptosis in the hippocampal CA1 region. The expression levels of cleaved Caspase-3 and cleaved Caspase-8 proteins were significantly increased in the hippocampus, but the expression levels of TLR4 and NF-κB p65 were not increased. The activation of IFITM3 may be a potential new target for treating sepsis-associated encephalopathy (SAE), and it may be one of the key anti-apoptotic mechanisms in rhBNP exerting its therapeutic effect, providing new insight into the clinical treatment of SAE patients.

Evolution of primate interferon-induced transmembrane proteins (IFITMs): a story of gain and loss with a differentiation into a canonical cluster and IFITM retrogenes.

Interferon-inducible transmembrane proteins (IFITMs) are a family of transmembrane proteins. The subgroup of immunity-related (IR-)IFITMs is involved in adaptive and innate immune responses, being especially active against viruses. Here, we suggest that IFITMs should be classified as (1) a canonical IFITM gene cluster, which is located on the same chromosome, and (2) IFITM retrogenes, with a random and unique location at different positions within the genome. Phylogenetic analyses of the canonical cluster revealed the existence of three novel groups of primate IFITMs (pIFITM) in the IR-IFITM clade: the prosimian pIFITMs(pro), the new world monkey pIFITMs(nwm) and the old world monkey pIFITMs(owm). Therefore, we propose a new nomenclature: IR-pIFITM1, IR-pIFITM2, IR-pIFITM3, IR-pIFITMnwm, IR-pIFITMowm, and IR-pIFITMpro. We observed divergent evolution for pIFITM5 and pIFITM10, and evidence for concerted evolution and a mechanism of birth-and-death evolution model for the IR-pIFITMs. In contrast, the IFITMs scattered throughout the genomes possessed features of retrogenes retrotransposed by class 1 transposable elements. The origin of the IFITM retrogenes correspond to more recent events. We hypothesize that the transcript of a canonical IFITM3 has been constantly retrotransposed using class 1 transposable elements resulting in the IFITM retro(pseudo)genes. The unique pattern of each species has most likely been caused by constant pseudogenization and loss of the retro(pseudo)genes. This suggests a third mechanism of evolution for the IR-IFITMs in primates, similar to the birth-and-death model of evolution, but via a transposable element mechanism, which resulted in retro(pseudo)genes.

Influence of the Single Nucleotide Polymorphisms rs12252 and rs34481144 in IFITM3 on the Antibody Response after Vaccination against COVID-19.

The COVID-19 mRNA vaccine is the first mRNA vaccine approved for human administration by both the U.S. Food and Drug Administration and the European Medicines Agency. Studies have shown that the immune response and the decay of immunity after vaccination with the COVID-19 vaccines are variable within a population. Host genetic factors probably contribute to this variability. In this study, we investigated the effect of the single-nucleotide polymorphisms rs12252 and rs34481144 in the interferon-induced transmembrane protein (IFITM) 3 gene on the humoral immune response after vaccination against COVID-19 with mRNA vaccines. Blood samples were collected from 1893 healthcare workers and medical students at multiple time points post-vaccination and antibody titers against the SARS-CoV-2 S1 protein receptor binding domain were determined at all time points. All participants were genotyped for the rs34481144 and rs12252 polymorphisms in the IFITM3 gene. After the second and third vaccinations, antibody titer levels increased at one month and decreased at six months (p < 0.0001) and were higher after the booster vaccination than after the basic immunization (p < 0.0001). Participants vaccinated with mRNA-1273 had a higher humoral immune response than participants vaccinated with BNT162b2. rs12252 had no effect on the antibody response. In contrast, carriers of the GG genotype in rs34481144 vaccinated with BNT162b2 had a lower humoral immune response compared to A allele carriers, which reached statistical significance on the day of the second vaccination (p = 0.03) and one month after the second vaccination (p = 0.04). Further studies on the influence of rs12252 and rs34481144 on the humoral immune response after vaccination against COVID-19 are needed.

Interferon alpha and beta receptor 1 knockout in human embryonic kidney 293 cells enhances the production efficiency of proteins or adenoviral vectors related to type I interferons.

Human embryonic kidney (HEK) 293 cells are widely used in protein and viral vector production owing to their high transfection efficiency, rapid growth, and suspension growth capability. Given their antiviral, anticancer, and immune-enhancing effects, type I interferons (IFNs) have been used to prevent and treat human and animal diseases. However, the binding of type I IFNs to the IFN-α and-β receptor (IFNAR) stimulates the expression of IFN-stimulated genes (ISGs). This phenomenon induces an antiviral state and promotes apoptosis in cells, thereby impeding protein or viral vector production. In this study, we generated an IFNAR subtype 1 knockout (KO) HEK 293 suspension (IFNAR-KO) cell line by using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 nuclease (Cas9) technology. Upon treatment with human IFN-α, the IFNAR-KO cells showed a constant expression of ISGs, including 2'-5'-oligoadenylate synthetase 1 (OAS1), myxovirus resistance 1 (Mx1), protein kinase RNA-activated (PKR), and IFN-induced transmembrane protein 1 (IFITM1), when compared with the wild-type HEK 293 (WT) cells, wherein the ISGs were significantly upregulated. As a result, the titer of recombinant adenovirus expressing porcine IFN-α was significantly higher in the IFNAR-KO cells than in the WT cells. Furthermore, the IFNAR-KO cells continuously produced higher amounts of IFN-α protein than the WT cells. Thus, the CRISPR-Cas9-mediated IFNAR1 KO cell line can improve the production efficiency of proteins or viral vectors related to IFNs. The novel cell line may be used for producing vaccines and elucidating the type I IFN signaling pathway in cells.

IFITM3 restricts RABV infection through inhibiting viral entry and mTORC1- dependent autophagy

Rabies, which caused by rabies virus (RABV), is a zoonotic and life-threatening disease with 100% mortality, and there is no effective treatment thus far due to the unclear pathogenesis and less of treatment targets. Interferon-induced transmembrane protein 3 (IFITM3) has recently been identified as an important anti-viral host effector induced by type I interferon. However, the role of IFITM3 in RABV infection has not been elucidated. In this study, we demonstrated that IFITM3 is a crucial restriction factor for RABV, the viral-induced IFITM3 significantly inhibited RABV replication, while knockdown of IFITM3 had the opposite effect. We then identified that IFNβ induces the upregulation of IFITM3 in the absence or presence of RABV infection, meanwhile, IFITM3 positively regulates RABV-triggered production of IFNβ in a feedback manner. In-depth research we found that IFITM3 not only inhibits the virus absorb and entry, but also inhibits viral replication through mTORC1-dependent autophagy. All these findings broaden our understanding of IFITM3 function and uncover a novel mechanism against RABV infection.

Interferon-induced transmembrane protein 3 in hepatocellular carcinoma patients

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.