Viral Immune Escape Research Articles

Ubiquitination and degradation of MHC-II by Tim-3 inhibits antiviral immunity

We previously reported that Tim-3, an immune checkpoint inhibitor, inhibits MHC-II expression, but the molecular mechanisms involved and the implications for antiviral immunity remain to be determined. Here, we found that during H1N1 infection, Tim-3 inhibits MHC-II expression in macrophages/microglia in vitro. Tim-3 interacts with MHC-II via its intracellular tail and induces proteasomal dependent degradation of MHC-II. In H1N1 infected macrophages/microglia, Tim-3 promotes the K48-linked ubiquitination of MHC-II via MARCH8, a ubiquitin E3 ligase that can be upregulated by Tim-3. In H1N1 infected mice, specific knockout of Tim-3 in macrophages leads to a decreased viral load, attenuates tissue damage and increases the survival rate. We have thus identified a novel mechanism by which Tim-3 mediates virus immune escape. Manipulating the Tim-3-MHC-II signaling pathway may provide a novel treatment for viral infections.

PUS6 in pseudorabies virus participates in the process of inhibiting antigen presentation by inhibiting the assembly of peptide loading complex.

Pseudorabies virus (PRV) can establish lifelong latent infection in peripheral nervous ganglion, and persistent infections in peripheral blood lymphocytes. Establishing an infection in the lymphocytes does not only enable the PRV to escape host immune surveillance but pass through the placental barrier, leading to fetal death and abortion. Due to the pathogenicity of the PRV, it poses a huge challenge in its prevention and control. The PRV escapes host immunity through downregulation of swine leukocyte antigen class I (SLA I) molecules on infected cells. However, data on the molecular mechanisms of the SLA I suppression remains scant. Here, in order to verify the effect of candidate proteins PRV pUL44 and pUS6 on PRV immune escape related molecules SLA I and peptide loading complex (PLC), we detected the expression of SLA I and PLC components after expressing PRV pUL44 and pUS6. The effects of pUS6 and pUL44 on SLA I and PLC were analyzed by qRT-PCR and Western blot at mRNA and protein level, respectively. Cells expressing pUS6 or pUL44 genes showed a significantly suppressed expression of surface and total SLA I molecules. In addition, unlike UL44, the US6 gene was shown to downregulate the transporter associated with antigen processing 1 (TAP1), TAP2 and Tapasin molecules. The results show that PRV pUS6 may participate in virus immune escape by directly regulating the SLA I, TAP dimer and Tapasin molecules, thus blocking the transportation of TAP-bound peptides to the ER to bind SLA I molecules. We provide a theoretical basis on the mechanism of TAP mediated immune escape by the PRV.

The roles of rabies virus structural proteins in immune evasion and implications for vaccine development.

Rabies is a zoonotic infectious disease that targets the nervous system of human and animals and has about 100% fatality rate without treatment. Rabies virus is a bullet-like viral particle composed of five structural proteins, including nucleoprotein (N), phosphorylated protein (P), matrix protein (M), glycoprotein (G), and large subunit (L) of RNA-dependent RNA polymerase. These multifunctional viral proteins also play critical roles in the immune escape by inhibiting specific immune responses in the host, resulting in massive replication of the virus in the nervous system and abnormal behaviors of patients such as brain dysfunction and hydrophobia, which ultimately lead to the death of patients. Herein, the role of five structural proteins of rabies virus in the viral replication and immune escape and its implication for the development of vaccines were systemically reviewed, so as to shed light on the understanding of pathogenic mechanism of rabies virus.

Semi-Covariance Coefficient Analysis of Spike Proteins from SARS-CoV-2 and Its Variants Omicron, BA.5, EG.5, and JN.1 for Viral Infectivity, Virulence and Immune Escape.

Semi-covariance has attracted significant attention in recent years and is increasingly employed to elucidate statistical phenomena exhibiting fluctuations, such as the similarity or difference in charge patterns of spike proteins among coronaviruses. In this study, by examining values above and below the average/mean based on the positive and negative charge patterns of amino acid residues in the spike proteins of SARS-CoV-2 and its current circulating variants, the proposed methods offer profound insights into the nonlinear evolving trends in those viral spike proteins. Our study indicates that the charge span value can predict the infectivity of the virus and the charge density can estimate the virulence of the virus, and both predicated infectivity and virulence appear to be associated with the capability of viral immune escape. This semi-covariance coefficient analysis may be used not only to predict the infectivity, virulence and capability of immune escape for coronaviruses but also to analyze the functionality of other viral proteins. This study improves our understanding of the trend of viral evolution in terms of viral infectivity, virulence or the capability of immune escape, which remains further validated by more future studies and statistical data.

Engineering immune-evasive allogeneic cellular immunotherapies.

Allogeneic cellular immunotherapies hold a great promise for cancer treatment owing to their potential cost-effectiveness, scalability and on-demand availability. However, immune rejection of adoptively transferred allogeneic T and natural killer (NK) cells is a substantial obstacle to achieving clinical responses that are comparable to responses obtained with current autologous chimeric antigen receptor T cell therapies. In this Perspective, we discuss strategies to confer cell-intrinsic, immune-evasive properties to allogeneic T cellsand NK cells in order to prevent or delay their immune rejection, thereby widening the therapeutic window. We discuss how common viral and cancer immune escape mechanisms can serve as a blueprint for improving the persistence of off-the-shelf allogeneic cell therapies. The prospects of harnessing genome editing and synthetic biology to design cell-based precision immunotherapies extend beyond programming target specificities and require careful consideration of innate and adaptive responses in the recipient that may curtail the biodistribution, in vivo expansion and persistence of cellular therapeutics.

Breakthrough Mpox Outbreak Investigation, the Delicate Balance Between Host Immune Response and Viral Immune Escape.

Limited data are available on Mpox breakthrough infections. The purpose of this study is to investigate a Mpox breakthrough outbreak in 3 vaccinated individuals. Study participants provided informed consent. Serology testing was performed in one involved individual (ID-1) using an in-house assay detecting anti-orthopoxvirus IgG. Whole genome sequencing (WGS) was carried out and compared with the reference sequence ON563414.3 ( https://www.ncbi.nlm.nih.gov/nuccore/ON563414.3/ ). Three individuals vaccinated with modified vaccinia Ankara-Bavaria Nordic contracted Mpox following one sexual intercourse event. One of them (ID-1) had received only one vaccine dose, while the other two were fully vaccinated. ID-1 presented to the sexual health clinic of the Universitair Ziekenhuis Brussel with proctitis related to Mpox. Despite one vaccination, serology testing Three months post vaccine showed absence of Mpox virus (MPXV) specific antibodies in ID-1. In contrast, 2 weeks after the sexual intercourse, seroconversion occurred. Whole genome sequencing of the isolated MPXV showed, compared with the reference sequence, a total of seven single nucleotide variants with four of them indicating protein amino-acid changes. Incomplete MPXV vaccination as well as MPXV variants might result in breakthrough infections. Preventive measures, such as MPVX vaccination, could maintain immunity in individuals with higher risk of MPXV infection, and might lower disease severity.

C1q enables influenza hemagglutinin stem binding antibodies to block viral attachment and broadens the antibody escape repertoire.

Antigenic drift, the gradual accumulation of amino acid substitutions in the influenza virus hemagglutinin (HA) receptor protein, enables viral immune evasion. Antibodies (Abs) specific for the drift-resistant HA stem region are a promising universal influenza vaccine target. Although anti-stem Abs are not believed to block viral attachment, here we show that complement component 1q (C1q), a 460-kilodalton protein with six Ab Fc-binding domains, confers attachment inhibition to anti-stem Abs and enhances their fusion and neuraminidase inhibition. As a result, virus neutralization activity in vitro is boosted up to 30-fold, and in vivo protection from influenza PR8 infection in mice is enhanced. These effects reflect increased steric hindrance and not increased Ab avidity. C1q greatly expands the anti-stem Ab viral escape repertoire to include residues throughout the HA, some of which cause antigenic alterations in the globular region or modulate HA receptor avidity. We also show that C1q enhances the neutralization activity of non-receptor binding domain anti-SARS-CoV-2 spike Abs, an effect dependent on spike density on the virion surface. These findings demonstrate that C1q can greatly expand Ab function and thereby contribute to viral evolution and immune escape.

The Molecular Characterization of the Cyprinid herpesvirus 3 (CyHV-3) ORF24 Protein and its effect on the expression of immune genes (in vitro)

Cyprinid herpesvirus 3 (CyHV-3), known as koi herpesvirus (KHV), is highly contagious and lethal. In this study, we aimed to characterize the ORF24-encoding protein of CyHV-3, investigate its sub-cellular localization, and determine its impact on the expression of immune factors through in vitro experiments. The results showed that the CyHV-3 ORF24 protein comprises 579 amino acids. Interestingly, multiple comparisons with homologous proteins from three carp herpesvirus origins showed no significant similarity. The fluorescence localization experiment showed that the green fluorescence signal, representing the protein pEGFP-ORF24, was primarily diffused in the cytoplasm. Notably, the overexpression of ORF24 effectively suppressed the expression of immune factors in both CCO (Channel catfish ovary) and FHM (Fathead minnow muscle cell line) cells. Bioinformatic analysis indicated that the CyHV-3 ORF24 gene exhibited significant differences from the corresponding genes in the other two carp herpesviruses. This suggests its unique functional role in the evolutionary context. Moreover, our findings demonstrated that overexpression of CyHV-3 ORF24 can effectively inhibit the expression of immune factors, underscoring its crucial role as a viral immune escape factor. These results provide further insights into the immune function of the CyHV-3 ORF24 protein and offer a theoretical foundation for developing new vaccines against CyHV-3 virus infections.

Mass Spectrometry-Based Proteomic Analysis of Potential Host Proteins Interacting with GP5 in PRRSV-Infected PAMs.

Porcine reproductive and respiratory syndrome virus (PRRSV) is a typical immunosuppressive virus causing a large economic impact on the swine industry. The structural protein GP5 of PRRSV plays a pivotal role in its pathogenicity and immune evasion. Virus-host interactions play a crucial part in viral replication and immune escape. Therefore, understanding the interactions between GP5 and host proteins are significant for porcine reproductive and respiratory syndrome (PRRS) control. However, the interaction network between GP5 and host proteins in primary porcine alveolar macrophages (PAMs) has not been reported. In this study, 709 GP5-interacting host proteins were identified in primary PAMs by immunoprecipitation coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Bioinformatics analysis revealed that these proteins were involved in multiple cellular processes, such as translation, protein transport, and protein stabilization. Subsequently, immunoprecipitation and immunofluorescence assay confirmed that GP5 could interact with antigen processing and presentation pathways related proteins. Finally, we found that GP5 may be a key protein that inhibits the antigen processing and presentation pathway during PRRSV infection. The novel host proteins identified in this study will be the candidates for studying the biological functions of GP5, which will provide new insights into PRRS prevention and vaccine development.

The LxIS motif is the language between virus and host RLRs: From fish to mammalian viruses

Regulation of host interferon (IFN) production is a crucial strategy for viral immune escape. We propose that the LxIS motif language, a marker for exogenous viral proteins, interacts with host retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) factors. In this study, the viral proteins containing the LxIS motif of grass carp reovirus (GCRV), and cyprinid herpesvirus 3 (CyHV-3), which belong to the fish RNA and DNA viruses, were found to interact with RLRs, and the general functions of these proteins were negative regulation of IFN activation. Terrestrial animal viruses with this motif language, such as SARS-CoV-2 and so on, are also examined. Several viral proteins that were not reported previously were found to be associated with the RLR pathway. Taken together, the LxIS motif language elucidates a straightforward and efficient method for identifying viral proteins that target host RLRs to regulate IFN expression, and is conserved in both lower and higher vertebrates.

HIV-1 envelope facilitates the development of protease inhibitor resistance through acquiring mutations associated with viral entry and immune escape.

There is increasing evidence supporting a role for HIV-1 envelope in the development of Protease Inhibitor drug resistance, and a recent report from our group suggested that Env mutations co-evolve with Gag-Protease mutations in the pathway to Lopinavir resistance. In this study, we investigated the effect of co-evolving Env mutations on virus function and structure. Co-receptor usage and n-linked glycosylation were investigated using Geno2Pheno as well as tools available at the Los Alamos sequence database. Molecular dynamics simulations were performed using Amber 18 and analyzed using Cpptraj, and molecular interactions were calculated using the Ring server. The results showed that under Protease Inhibitor drug selection pressure, the envelope gene modulates viral entry by protecting the virus from antibody recognition through the increased length and number of N-glycosylation sites observed in V1/V2 and to some extent V5. Furthermore, gp120 mutations appear to modulate viral entry through a switch to the CXCR4 coreceptor, induced by higher charge in the V3 region and specific mutations at the coreceptor binding sites. In gp41, S534A formed a hydrogen bond with L602 found in the disulfide loop region between the Heptad Repeat 1 and Heptad Repeat 2 domains and could negatively affect the association of gp120-gp41 during viral entry. Lastly, P724Q/S formed both intermolecular and intramolecular interactions with residues within the Kennedy loop, a known epitope. In conclusion, the results suggest that mutations in envelope during Protease Inhibitor treatment failure are related to immune escape and that S534A mutants could preferentially use the cell-to-cell route of infection.

CircMORC3-encoded novel protein negatively regulates antiviral immunity through synergizing with host gene MORC3.

The protein-coding ability of circRNAs has recently been a hot topic, but the role of protein-coding circRNAs in antiviral innate immunity of teleost fish has rarely been reported. Here, we identified a novel circRNA, termed circMORC3, derived from Microrchidia 3 (MORC3) gene in Miichthys miiuy. circMORC3 can inhibit the expression of antiviral cytokines. In addition, circMORC3 encodes a novel peptide with a length of 84 amino acids termed MORC3-84aa. MORC3-84aa not only significantly inhibited TRIF-mediated activation of IRF3 and NF-κB signaling pathways, but also effectively suppressed the expression of antiviral cytokines triggered by RNA virus Siniperca chuatsi rhabdovirus (SCRV). We found that MORC3-84aa directly interacted with TRIF and negatively regulated TRIF protein expression. In addition, host gene MORC3 attenuates SCRV-induced IFN and ISG expression. Mechanistically, MORC3-84aa promotes autophagic degradation of TRIF by enhancing K6-linked ubiquitination and inhibits TRIF-mediated activation of the type I interferon signaling pathway. And the host gene MORC3 not only repressed IRF3 protein expression but also inhibited IRF3 phosphorylation levels. Our study shows that circMORC3 and host gene MORC3 played a synergistic role in viral immune escape.

Molecular biology of canine parainfluenza virus V protein and its potential applications in tumor immunotherapy.

Canine parainfluenza virus (CPIV) is a zoonotic virus that is widely distributed and is the main pathogen causing canine infectious respiratory disease (CIRD), also known as "kennel cough," in dogs. The CPIV-V protein is the only nonstructural protein of the virus and plays an important role in multiple stages of the virus life cycle by inhibiting apoptosis, altering the host cell cycle and interfering with the interferon response. In addition, studies have shown that the V protein has potential applications in the field of immunotherapy in oncolytic virus therapy or self-amplifying RNA vaccines. In this review, the biosynthesis, structural characteristics and functions of the CPIV-V protein are reviewed with an emphasis on how it facilitates viral immune escape and its potential applications in the field of immunotherapy. Therefore, this review provides a scientific basis for research into the CPIV-V protein and its potential applications.

A Modified Recombinant DNA-Based SARS-CoV-2 Vaccine Expressing Stabilized Uncleavable Spike Protein Elicits Humoral and Cellular Immunity against Various SARS-CoV-2 Variants of Concern

The appearance of several variants of concern (VOCs) of SARS-CoV-2 affects the efficacy of currently available vaccines and causes continuous spread and reinfection between humans. These variants possess different spike (S) protein mutations, which could affect viral pathogenicity, transmission, and immune escape. Herein, we develop a synthetic codon-optimized DNA vaccine (VIU-1007) expressing full-length S protein. The developed vaccine is stabilized by two K986P and V987P proline substitutions and resistant to cleavage by proteases such as furin by deletion of arginine residues (R682, R683, and R685) in multibasic furin cleavage site (RRAR). Additionally, it carries K417N, E484K, N501Y, and D614G substitutions in the receptor binding domain (RBD) derived from the beta VOC. Following the validation and characterization of the in vitro S protein expression, the humoral and cellular immunogenicity of VIU-1007 was assessed in immunized Balb/c mice. While both regimens elicited a Th-1-biased immune response based on S1-specific binding IgG isotypes, three vaccine doses significantly enhanced IgG levels. Furthermore, CD4+ and CD8+ memory T cell responses in spleens and draining inguinal lymph nodes were significantly higher in mice received three doses of VIU-1007 when compared to those received two doses only. Importantly, sera from mice immunized with three doses showed broad neutralization breadth against several SARS-CoV-2 variants, including alpha, beta, gamma, delta, and omicron VOCs. Moreover, the sera showed limited neutralization capacity against SARS-CoV-1, Bat SARS-like coronavirus WIV1, and MERS-CoV. Together, while these data suggest the presence of common neutralizing-rich epitopes between SARS-CoV-2 variants and some other betacoronaviruses, the ongoing evolution of SARS-CoV-2 could result in escape from vaccine-induced immunity, which requires a continuous update of vaccines.

Identification of four neutralizing antigenic sites on the enterovirus D68 capsid.

Enterovirus D68 (EV-D68) is an emerging respiratory pathogen associated with acute flaccid myelitis. Currently, no approved vaccines or antiviral drugs are available. Here, we report four functionally independent neutralizing antigenic sites (I to IV) by analyses of neutralizing monoclonal antibody (MAb)-resistant mutants. Site I is located in the VP1 BC loop near the fivefold axis. Site II resides in the VP2 EF loop, and site III is situated in VP1 C-terminus; both sites are located at the south rim of the canyon. Site IV is composed of residue in VP2 βB strand and residues in the VP3 BC loop and resides around the threefold axis. The developed MAbs targeting the antigenic sites can inhibit viral binding to cells. These findings advance the understanding of the recognition of EV-D68 by neutralizing antibodies and viral evolution and immune escape and also have important implications for the development of novel EV-D68 vaccines.

Deciphering the rule of antigen-antibody amino acid interaction.

Antigenic drift is the biggest challenge for mutagenic RNA virus vaccine development. The primary purpose is to determine the IEMM (immune escape mutation map) of 20 amino acids' replacement to reveal the rule of the viral immune escape. To determine the relationship between epitope mutation and immune escape, we use universal protein tags as a linear epitope model. To describe and draw amino acid linkage diagrams, mutations of protein tags are classified into four categories: IEM (immune escape mutation), ADERM (antibody-dependent enhancement risk mutation), EQM (equivalent mutation), and IVM (invalid mutation). To overcome the data limitation, a general antigen-antibody (Ag-Ab) interaction map was constructed by analyzing the published three-dimensional (3D) Ag-Ab interaction patterns. (i) One residue interacts with multiple amino acids in antigen-antibody interaction. (ii) Most amino acid replacements are IVM and EQM. (iii) Once aromatic amino acids replace non-aromatic amino acids, the mutation is often IEM. (iv) Substituting residues with the same physical and chemical properties easily leads to IVM. Therefore, this study has important theoretical significance for future research on antigenic drift, antibody rescue, and vaccine renewal design. The antigenic epitope mutations were typed into IEM, ADERM, EQM, and IVM types to describe and quantify the results of antigenic mutations. The antigen-antibody interaction rule was summarized as a one-to-many interaction rule. To sum up, the epitope mutation rules were defined as IVM and EQM predomination rules and the aryl mutation escape rule.

Preferential selection of viral escape mutants by CD8+ T cell 'sieving' of SIV reactivation from latency.

HIV rapidly rebounds after interruption of antiretroviral therapy (ART). HIV-specific CD8+ T cells may act to prevent early events in viral reactivation. However, the presence of viral immune escape mutations may limit the effect of CD8+ T cells on viral rebound. Here, we studied the impact of CD8 immune pressure on post-treatment rebound of barcoded SIVmac293M in 14 Mamu-A*01 positive rhesus macaques that initiated ART on day 14, and subsequently underwent two analytic treatment interruptions (ATIs). Rebound following the first ATI (seven months after ART initiation) was dominated by virus that retained the wild-type sequence at the Mamu-A*01 restricted Tat-SL8 epitope. By the end of the two-month treatment interruption, the replicating virus was predominantly escaped at the Tat-SL8 epitope. Animals reinitiated ART for 3 months prior to a second treatment interruption. Time-to-rebound and viral reactivation rate were significantly slower during the second treatment interruption compared to the first. Tat-SL8 escape mutants dominated early rebound during the second treatment interruption, despite the dominance of wild-type virus in the proviral reservoir. Furthermore, the escape mutations detected early in the second treatment interruption were well predicted by those replicating at the end of the first, indicating that escape mutant virus in the second interruption originated from the latent reservoir as opposed to evolving de novo post rebound. SL8-specific CD8+ T cell levels in blood prior to the second interruption were marginally, but significantly, higher (median 0.73% vs 0.60%, p = 0.016). CD8+ T cell depletion approximately 95 days after the second treatment interruption led to the reappearance of wild-type virus. This work suggests that CD8+ T cells can actively suppress the rebound of wild-type virus, leading to the dominance of escape mutant virus after treatment interruption.

COV2Var, a function annotation database of SARS-CoV-2 genetic variation.

The COVID-19 pandemic, caused by the coronavirus SARS-CoV-2, has resulted in the loss of millions of lives and severe global economic consequences. Every time SARS-CoV-2 replicates, the viruses acquire new mutations in their genomes. Mutations in SARS-CoV-2 genomes led to increased transmissibility, severe disease outcomes, evasion of the immune response, changes in clinical manifestationsand reducing the efficacy of vaccines or treatments. To date, the multiple resources provide lists of detected mutations without key functional annotations. There is a lack of research examining the relationship between mutations and various factors such as disease severity, pathogenicity, patient age, patient gender, cross-species transmission, viral immune escape, immune response level, viral transmission capability, viral evolution, host adaptability, viral protein structure, viral protein function, viral protein stabilityand concurrent mutations. Deep understanding the relationship between mutation sites and these factors is crucial for advancing our knowledge of SARS-CoV-2 and for developing effective responses. To fill this gap, we built COV2Var, a function annotation database of SARS-CoV-2 genetic variation, available at http://biomedbdc.wchscu.cn/COV2Var/. COV2Var aims to identify common mutations in SARS-CoV-2 variants and assess their effects, providing a valuable resource for intensive functional annotations of common mutations among SARS-CoV-2 variants.

A Synopsis of Hepatitis C Virus Treatments and Future Perspectives.

Hepatitis C virus (HCV) infection is a worldwide public health problem. Chronic infection with HCV can lead to liver cirrhosis or cancer. Although some immune-competent individuals can clear the virus, others develop chronic HCV disease due to viral mutations or an impaired immune response. IFNs type I and III and the signal transduction induced by them are essential for a proper antiviral effect. Research on the viral cycle and immune escape mechanisms has formed the basis of therapeutic strategies to achieve a sustained virological response (SVR). The first therapies were based on IFNα; then, IFNα plus ribavirin (IFN-RBV); and then, pegylated-IFNα-RBV (PEGIFNα-RIV) to improve cytokine pharmacokinetics. However, the maximum SVR was 60%, and several significant side effects were observed, decreasing patients' treatment adherence. The development of direct-acting antivirals (DAAs) significantly enhanced the SVR (>90%), and the compounds were able to inhibit HCV replication without significant side effects, even in paediatric populations. The management of coinfected HBV-HCV and HCV-HIV patients has also improved based on DAA and PEG-IFNα-RBV (HBV-HCV). CD4 cells are crucial for an effective antiviral response. The IFNλ3, IL28B, TNF-α, IL-10, TLR-3, and TLR-9 gene polymorphisms are involved in viral clearance, therapeutic responses, and hepatic pathologies. Future research should focus on searching for strategies to circumvent resistance-associated substitution (RAS) to DAAs, develop new therapeutic schemes for different medical conditions, including organ transplant, and develop vaccines for long-lasting cellular and humoral responses with cross-protection against different HCV genotypes. The goal is to minimise the probability of HCV infection, HCV chronicity and hepatic carcinoma.

Virus-induced lncRNA-BTX allows viral replication by regulating intracellular translocation of DHX9 and ILF3 to induce innate escape

The roles of long noncoding RNA (lncRNA) and RNA-binding proteins (RBPs) in antiviral innate response warrant further investigation. Here, we identify an lncRNA, termed lncRNA-BTX (between Tbk1 and Xpot), which is upregulated upon viral infection via an IRF3-type I interferon-independent pathway, promoting viral innate immune escape. Deletion of lncRNA-BTX in cells or mice significantly reduces viral load invitro or invivo, respectively. Mechanistically, lncRNA-BTX strengthens the interactions between DHX9 or ILF3 (two RBPs that have opposite functions in regulating the replication of RNA virus) and their respective partner, JMJD6 or ILF2, which regulates intracellular translocations of DHX9 and ILF3 from the nucleus to the cytoplasm. Put simply, lncRNA-BTX facilitates DHX9's return to the cytoplasm and retains ILF3 within the nucleus, promoting viral replication. This work unveils a strategy developed by the virus to bypass host innate immunity, thus providing a potential target for antiviral therapeutics.