MAVS operates downstream of cytosolic viral RNA sensing and coordinates antiviral responses through type I interferon and nuclear factor kappa B (NF-κB) signaling. The review examines how this signaling intersects with activation of the NLRP3 inflammasome. In the pathway described, MAVS contributes to inflammasome activation, which is followed by caspase-1 activation, gasdermin D cleavage, cytokine release and pyroptotic cell death. These linked events provide a mechanistic explanation for how viral recognition can generate both antiviral activity and inflammatory responses. Rather than assigning MAVS a single role, the review presents it as a signaling hub whose effects depend on the cellular context and the downstream pathway that becomes engaged.

The clearest HIV-1-specific contrasts in the review emerge from the different outcomes in myeloid cells, macrophages and quiescent CD4+ T cells. In myeloid cells and macrophages, HIV-1 has evolved several mechanisms that dampen MAVS-dependent antiviral responses. This suppression can weaken innate controls on replication and create conditions favorable to viral replication and persistence. The review also emphasizes that mechanisms demonstrated in HIV-1 infection models should not be conflated with findings established in other viral systems. Its central model is therefore not that every viral sensing event converges on MAVS, but that HIV-1 regulates innate pathways in a cell type-dependent manner, suppressing antiviral activity in some compartments while allowing or promoting inflammatory pathways in others.

Abortive infection of quiescent CD4+ T cells follows a distinct route in the evidence summarized by the review. Rather than requiring MAVS, this response uses IFI16-dependent, caspase-1-mediated pyroptosis. The authors describe this MAVS-independent pathway as a major contributor to CD4+ T-cell depletion and chronic inflammation. The distinction matters because it separates MAVS-dependent signaling from inflammasome activation that can occur without MAVS. The review also discusses emerging evidence for CARD8-mediated inflammasome activation, identifying it as another potential route through which innate pathways may complement antiviral defense while influencing HIV-1 pathogenesis. These findings broaden the network under consideration beyond a single MAVS-centered axis and show that different inflammasome pathways can be associated with distinct outcomes.

The review places these mechanistic observations in the broader problem that HIV-1 is not cured by antiretroviral therapy because latent viral reservoirs persist and chronic immune activation continues alongside infection. Its proposed significance is that understanding how MAVS, inflammasomes and pyroptosis interact across different cell types may open possibilities for host-directed approaches intended to limit viral persistence and reduce chronic inflammation. That remains a research direction, not an established treatment or demonstrated clinical benefit. The evidence reviewed is primarily mechanistic and draws on multiple experimental systems; the authors explicitly distinguish observations made in HIV-1 models from evidence derived from other viral infections and from connections that still need validation in HIV-1.

Subject of Research: Cell-specific MAVS-dependent and independent inflammasome signaling in HIV-1 infection

Article Title: MAVS signaling in HIV-1 infection: linking innate viral sensing to inflammasome activation, pyroptosis and viral persistence

Article References: Nesci, S., Glogowski, P. A., Cugliari, A., Trombetti, F., & Algieri, C. (2026). MAVS signaling in HIV-1 infection: linking innate viral sensing to inflammasome activation, pyroptosis and viral persistence. Journal of Translational Medicine. https://doi.org/10.1186/s12967-026-09119-5

Image Credits: AI Generated

DOI: 10.1186/s12967-026-09119-5

Keywords: HIV-1, MAVS, Inflammasomes, Pyroptosis, Innate immunity, CD4+ T cells, NLRP3, IFI16, CARD8, Viral persistence, signaling, infection

TONV belongs to the alphavirus genus, a group of enveloped RNA viruses transmitted primarily by mosquitoes and arthropods. While its close relatives, including Venezuelan equine encephalitis virus, chikungunya virus, and Mayaro virus, have received considerable attention from the research community, TONV has remained on the margins of virological research. Clinical reports associate the virus with febrile illness, encephalitis, and central nervous system abnormalities in fetuses, making it a pathogen of potential public health concern, particularly in regions where its mosquito vectors are established. Until now, however, almost nothing was known about which molecular sensors in human cells detect TONV upon infection and which signaling cascades are triggered to contain it.

The research team turned their attention to two well-established human cell lines, T98G glioblastoma cells and A549 lung epithelial cells, to dissect the interaction between TONV and the innate immune system. These cell types are commonly used to study antiviral responses because they mount robust and reproducible reactions to RNA virus infections. The investigators infected the cells with TONV and monitored the accumulation of viral genetic material and the activation of cellular defense pathways over time, using molecular techniques that allow visualization and quantification of viral components inside individual cells.

What they observed was a clear and rapid cellular alarm. TONV infection led to the accumulation of double-stranded RNA in the cytoplasm, the fluid interior of the cell where most metabolic activity takes place. Double-stranded RNA is a molecular signature that distinguishes many RNA viruses from the host cell’s own genetic material, which normally resides in the nucleus and does not form long double-stranded structures in the cytoplasm. This cytosolic double-stranded RNA acts as a danger signal, alerting the cell that something foreign is replicating inside it. The presence of this viral signature coincided with a robust activation of the type I interferon pathway, the body’s first-line antiviral defense mechanism that triggers the production of hundreds of interferon-stimulated genes capable of restricting viral replication.

To identify which cellular sensors were responsible for detecting TONV, the researchers systematically depleted key components of the RNA sensing machinery. They focused on RIG-I and MDA5, two cytoplasmic RNA helicases that function as pattern recognition receptors, meaning they patrol the cell interior looking for viral RNA signatures. When RIG-I or MDA5 detects viral RNA, it initiates a signaling cascade through an adaptor protein called MAVS, which resides on the outer membrane of mitochondria and other cellular organelles. MAVS, in turn, activates transcription factors, most notably IRF3, that travel to the cell nucleus and switch on the genes encoding type I interferons and other antiviral molecules. This pathway, known as the RLR-MAVS-IRF3 axis, is a central component of the cellular response to RNA viruses.

The experimental results were unambiguous. When the researchers depleted RIG-I, MDA5, MAVS, or IRF3 from the human cells, the TONV-induced interferon response was strongly reduced, demonstrating that each of these molecules is required for the cell to mount an effective alarm. More importantly, the loss of any of these components had direct consequences for viral replication. Cells lacking functional RIG-I, MDA5, MAVS, or IRF3 showed an increase in the proportion of cells containing detectable viral double-stranded RNA, indicating that more cells became productively infected. Viral RNA accumulation also rose significantly in these sensor-deficient cells, confirming that the RLR-MAVS-IRF3 axis actively restricts TONV replication rather than merely responding to it as a passive byproduct of infection.

These findings establish the RIG-I and MDA5 helicases as the primary sensors that detect TONV infection in human cells. The results also clarify the downstream signaling route: viral RNA recognition by RIG-I or MDA5 activates MAVS, which in turn triggers IRF3-dependent transcription of type I interferon genes. The interferon proteins released by infected cells then act in both autocrine and paracrine fashion, binding to receptors on the infected cell itself and on neighboring cells, priming them to express antiviral effector proteins before the virus can spread further. This coordinated response creates what immunologists call an antiviral state, a condition in which cells are metabolically and biochemically prepared to resist viral replication.

The researchers went one step further and asked whether exogenous type I interferon, supplied from outside the cells, could suppress TONV replication directly. The answer was emphatic. Treatment with recombinant type I interferon strongly inhibited TONV replication, reducing both the amount of viral RNA inside infected cells and the production of infectious viral particles released into the surrounding medium. This result confirms that the interferon pathway is not merely a marker of TONV infection but a functionally relevant antiviral mechanism capable of actively suppressing the virus. It also suggests that therapeutic strategies aimed at boosting type I interferon signaling could potentially be developed to limit TONV infection, although translating such findings from cell culture to clinical applications would require extensive further research.

The significance of this work extends beyond TONV itself. By identifying the RLR-MAVS-IRF3 axis as the major sensing pathway for this neglected alphavirus, the study fills a substantial gap in our understanding of how the alphavirus genus interacts with the human innate immune system. Different alphaviruses have evolved distinct strategies to evade or suppress host defenses, and knowing which pathways are engaged by TONV provides a foundation for comparative studies with its more notorious relatives. Such comparisons can reveal whether TONV lacks specific immune evasion mechanisms that make other alphaviruses more pathogenic, or whether it possesses unique strategies that could inform the design of broad-spectrum antiviral approaches.

Moreover, the study highlights the importance of investigating neglected pathogens even when they appear to be of limited immediate clinical relevance. The Venezuelan equine encephalitis complex includes viruses with the potential to cause outbreaks, and understanding the basic biology of how human cells respond to these agents is a prerequisite for developing vaccines, therapeutics, and diagnostic tools. The molecular characterization of TONV innate immune sensing presented by Labadie, Eloiflin, Denis, and their colleagues represents a foundational contribution to this effort, establishing a framework upon which future studies of alphavirus pathogenesis, host restriction factors, and antiviral immunity can be built. As climate change and urbanization continue to expand the geographic range of mosquito vectors, pathogens such as TONV may become increasingly relevant to global public health, making this type of fundamental research both timely and essential.

Subject of Research: Innate immune sensing of Tonate virus by the RIG-I, MDA5, MAVS, and IRF3 pathway in human cells

Article Title: The RLR-MAVS-IRF3 axis activates the IFN pathway to restrict Tonate virus (TONV) infection

Article References: Labadie, T., Eloiflin, R., Denis, Z., Motos, M., Re, J., Schussler, M., Chemarin, M., Moltini-Conclois, I., Courgnaud, V., Missé, D., Laguette, N., & Majzoub, K. (2026). The RLR-MAVS-IRF3 axis activates the IFN pathway to restrict Tonate virus (TONV) infection. PLOS Neglected Tropical Diseases, 20(10), e0014559. https://doi.org/10.1371/journal.pntd.0014559

Image Credits: AI Generated

DOI: 10.1371/journal.pntd.0014559

Keywords: Tonate virus, alphavirus, RIG-I, MDA5, MAVS, IRF3, type I interferon, innate immunity, antiviral response, Venezuelan equine encephalitis complex, double-stranded RNA, mosquito-borne virus

The review first lays out the molecular machinery. In the canonical pathway, loss of mitochondrial membrane potential stabilizes the serine/threonine kinase PINK1 on the outer mitochondrial membrane, where it phosphorylates and activates the E3 ubiquitin ligase Parkin. Parkin then decorates outer membrane proteins such as mitofusin-2 and VDAC1 with ubiquitin chains, which are recognized by cargo receptors including p62/SQSTM1, NDP52, optineurin, NBR1 and Tax1-binding protein 1. These receptors carry both ubiquitin-binding domains and LC3-interacting regions, physically bridging ubiquitinated mitochondria to LC3-positive autophagosomal membranes. Alongside this ubiquitin-driven route, noncanonical receptor-mediated mitophagy relies on mitochondrial proteins such as FUNDC1, BNIP3, BNIP3L/NIX, BCL2L13, AMBRA1, FKBP8, PHB2 and NLRX1, which bind LC3 and GABARAP family proteins directly through their own LIR motifs. Even mitochondrial lipids can act as eat-me signals: cardiolipin is externalized from the inner membrane by NDPK-D, and C18-ceramide generated by CerS1 binds LC3-II to trigger clearance.

The authors also describe mitochondria-derived vesicles, or MDVs, as a first-line quality-control system sometimes termed micromitophagy. Under basal conditions, single-membrane vesicles enriched in TOMM20 are formed in a DRP1- and MIRO-dependent manner, while stress induces PINK1/Parkin-dependent double-membrane vesicles containing matrix cargo such as pyruvate dehydrogenase, generated through OPA1, syntaxin 17 and sorting nexin 9. These vesicles ferry selected mitochondrial components to lysosomes, peroxisomes or multivesicular bodies, and can even be released as extracellular vesicles. Dysregulated MDV trafficking has been implicated in diseases including cancer metastasis, underscoring that mitochondrial quality control operates on several tiers before whole-organelle mitophagy is engaged.

Why does this matter for immunity? Because when mitophagy fails, mitochondria spill their contents. Mitochondrial DNA is rich in hypomethylated CpG motifs, making it a potent danger signal once it escapes into the cytosol or endosomes. Cytosolic mtDNA is sensed by cyclic GMP-AMP synthase, absent in melanoma 2 and Z-DNA binding protein 1, while endosomal mtDNA activates Toll-like receptor 9, and both native and oxidized mtDNA can fire the NLRP3 inflammasome. The cGAS-STING axis in particular drives interferon regulatory factor 3 activation, robust type I interferon production and NF-κB, STAT6 and MAPK signaling. Cells lacking PINK1 or Parkin accumulate cytosolic mtDNA and mount exaggerated cGAS-STING-dependent interferon responses, and impaired BNIP3L-dependent mitophagy promotes aggregation of the antiviral adaptor MAVS with heightened inflammatory cytokine output. Excessive type I interferon signaling, notably, is associated with worse outcomes in active pulmonary tuberculosis, illustrating that more immune activation is not always better.

Against this backdrop, the review catalogs how bacterial pathogens manipulate mitophagy to their advantage. Staphylococcus aureus induces mitophagy in macrophages through an HDAC11-suppression/IL-10 axis that dampens mTOR signaling, scavenging mitochondrial reactive oxygen species and promoting intracellular survival; the bacterium also hyperactivates the MEK1-ERK1/2 axis to suppress CHEK2, driving excessive mitophagy that impairs bactericidal activity. Burkholderia pseudomallei uses its type III secretion needle tip protein BipD to hijack a Kelch-like 9-kelch-like 13-cullin3 ubiquitin ligase complex, K63-ubiquitinating the inner membrane protein mitofilin and triggering p62-mediated mitophagy that suppresses mtROS. Neisseria gonorrhoeae delivers the porin PorB via outer membrane vesicles, dissipating membrane potential to activate PINK1- and OPTN/NDP52-dependent mitophagy while also recruiting RNF213 for K63-linked ubiquitination. Salmonella Typhimurium’s effector SseJ activates PINK1/Parkin mitophagy through the receptor PHB2, promoting bacterial persistence, and Listeria monocytogenes uses its virulence factor listeriolysin O to oligomerize NLRX1 and induce host mitophagy that keeps the bacterium alive.

Not all bacteria push mitophagy in the same direction, however, and the review is careful to note the exceptions. Helicobacter pylori’s CagA protein binds redistributed CYP11A1 and accelerates mitochondrial cholesterol accumulation, blocking mitophagy and thereby NLRP3 inflammasome activation and apoptosis of infected cells. Porphyromonas gingivalis disrupts mitophagic flux and lysosomal acidification in endothelial cells, preventing autophagic clearance and enabling persistent intracellular infection, even though PINK1/Parkin-mediated mitophagy can attenuate inflammation in periodontitis. In Mycobacterium tuberculosis infection, BNIP3-dependent mitophagy in macrophages lowers mtROS and favors bacterial survival, whereas Brucella abortus requires BNIP3L-mediated mitophagy for its egress from cells and cell-to-cell spread. Strikingly, in a model of bleomycin-induced lung injury, overgrowth of tissue-resident Klebsiella quasipneumoniae drove macrophage mitophagy and TGF-β1 production, linking mitophagy activation to pulmonary fibrosis through microbiota dysregulation.

Viruses, if anything, are even more inventive. Protective mitophagy is documented in coxsackievirus B3 myocarditis, where Parkin- and BNIP3-mediated clearance maintains cardiac function, and in Zika virus infection, where PINK1 activation suppresses replication and the uncoupling agent niclosamide inhibits the virus by promoting PINK1/Parkin mitophagy. But many viral effectors subvert the pathway. Herpes simplex virus 1 proteins ICP34.5 and US11 repress Parkin transcription through the EIF2S1-ATF axis, promoting infection and NF-κB-mediated neuroinflammation, while ICP0 depletes the autophagy adaptors p62 and optineurin. SARS-CoV-2 deploys multiple tools: ORF9b co-localizes with MAVS to suppress RIG-I-like receptor signaling, ORF10 translocates to mitochondria and degrades MAVS through mitophagy, and Spike 1 protein inhibits mitophagy while enhancing mtROS, NLRP3 activation and IL-18 maturation that drive cardiopulmonary inflammation. The influenza A virus proteins PB1-F2 and the nucleoprotein both induce TUFM- or toll-interacting protein-dependent mitophagy that blunts MAVS signaling, and respiratory syncytial virus NS1 acts as a bona fide mitophagy receptor by binding LC3B and TUFM.

The viral catalog extends across the animal and human pathogen spectrum. Varicella zoster virus glycoprotein E promotes DRP1-dependent fission and PINK1/Parkin mitophagy to block MAVS oligomerization and STING translocation. The severe fever with thrombocytopenia syndrome virus nucleoprotein recruits TUFM to degrade MAVS. Hepatitis C virus NS5A recruits NDP52 and optineurin to mitochondria; Senecavirus A protein 2C binds K27-ubiquitinated TUFM; African swine fever virus p17 links p62 to TOMM70; and classical swine fever virus nonstructural proteins co-opt the ESCRT machinery to close phagophores and accelerate mitophagy. Even the oncolytic Newcastle disease virus reprograms metabolism, degrading SIRT3 via PINK1/Parkin mitophagy to support replication, while enterovirus 71 uses PINK1/Parkin mitophagy to degrade MAVS and release virion-containing mitochondria into the extracellular space, aiding dissemination.

In sepsis, the picture becomes genuinely double-edged. Restoring mitophagy is generally beneficial: PINK1 protects dendritic cell function in cecal ligation puncture models; TMBIM1 and TMBIM6 preserve cardiac mitochondrial quality control; FUNDC1 ameliorates septic cardiomyopathy by suppressing ferroptosis; and bioinformatic clustering of 348 sepsis samples showed that the cluster with the highest mitophagy activity had the lowest disease severity, with prohibitin 1 negatively correlated with severity. Sirtuins are central players, with SIRT1-Rab7 and SIRT3-Parkin axes suppressing STING, NLRP3 and pyroptosis in lung injury, and melatonin attenuating septic kidney injury through SIRT3-mediated deacetylation of mitochondrial transcription factor A. Yet in polymicrobial sepsis, PINK1/Parkin-mediated mitophagy suppresses macrophage activation and impairs bacterial clearance, reducing mouse survival, a reminder that context determines whether mitophagy helps the host or the pathogen.

Therapeutically, the review highlights a growing pharmacopeia. The mitophagy activator ALT001 promotes ULK1/Rab9-dependent mitophagy and interferon-mediated antiviral defense against HSV-1; gut microbial metabolites nicotinamide N-oxide and taurine restore mitophagy in herpes simplex encephalitis; verbenalin, emodin, bergapten, dendrobine, puerarin, olaparib and even high-concentration hydrogen show protective effects in sepsis models through pathway-specific mitophagy activation. Conversely, mitochondrial division inhibitor-1 enhances SARS-CoV-2-specific CD8+ T cell responses by blocking excessive mitophagy-linked metabolic remodeling, and protopine and Liang-Ge-San alleviate lung injury by downregulating mitophagy in specific compartments. The authors conclude that selectively inducing or inhibiting mitophagy, tailored to pathogen and disease stage, represents a promising but still immature strategy, with key questions remaining about which mitophagy modes matter for which infections and how microbial effectors precisely co-opt the machinery. As the field matures, mitophagy modulation may become an adjunctive weapon against intractable infections and the inflammatory storm of sepsis.

Subject of Research: The role of mitophagy in bacterial and viral infection pathogenesis and sepsis, and its therapeutic modulation

Article Title: Mitophagy in pathogenesis and therapeutic implications for infection

Article References: Jung, B., Lee, B., Sapkota, A., Roh, T., Seo, W., Kim, J. K., & Jo, E.-K. (2026). Mitophagy in pathogenesis and therapeutic implications for infection. Experimental & Molecular Medicine. https://doi.org/10.1038/s12276-026-01852-7

Image Credits: AI Generated

DOI: 10.1038/s12276-026-01852-7

Keywords: mitophagy, autophagy, PINK1, Parkin, bacterial infection, viral infection, sepsis, mtDNA, cGAS-STING, NLRP3 inflammasome, MAVS, innate immunity

The type I interferon response is the cornerstone of innate antiviral immunity. When sensor proteins inside the cell detect viral RNA, they pass the signal along a molecular relay that converges on MAVS, the mitochondrial antiviral signaling protein, which sits on the outer membrane of mitochondria and related organelles. Once activated, MAVS recruits downstream signaling complexes that ultimately switch on transcription factors responsible for driving the production of interferon and inflammatory cytokines. These molecules then spread to neighboring cells, placing them into an antiviral state that makes replication of the virus far more difficult. Because this pathway is so potent, influenza A virus has evolved multiple proteins dedicated to interfering with it at different points, and mapping these interference strategies is essential for understanding viral pathogenesis.

NS2, also referred to in the literature as NEP, has traditionally been viewed as a logistics protein rather than an immune antagonist. It is a component of the viral particle and its best-characterized job is the nuclear export of viral ribonucleoprotein complexes, the vRNPs, which must travel from the nucleus, where the viral genome is transcribed and replicated, to the cytoplasm, where new virions are assembled. The new study, however, demonstrates that this protein has a second, hidden function. The authors report that NS2 suppresses type I interferon responses by physically interacting with UBL7, a ubiquitin-like protein also known as BMSC-UbP, which the study identifies as a positive regulator of interferon signaling that promotes K27-linked polyubiquitination of MAVS.

Ubiquitination is a versatile chemical modification in which ubiquitin molecules are attached to target proteins, and the way those ubiquitin chains are linked determines the biological outcome. K27-linked polyubiquitination of MAVS serves as a molecular scaffold signal that helps assemble the downstream activation complexes needed for robust interferon induction. UBL7 supports this process, acting as an enabler of MAVS activation. The new work shows that NS2 interferes with this enabling role. By binding to UBL7, the viral protein reduces the K27-linked polyubiquitination of MAVS and thereby hinders the productive interaction between UBL7 and MAVS. The consequence is a dampened activation of the entire interferon signaling cascade, giving the virus a wider window in which to replicate before the antiviral state takes hold.

The experimental logic behind this conclusion rested on a series of complementary approaches. The researchers examined the interaction between NS2 and UBL7 and demonstrated that this interaction competes with the association of UBL7 with MAVS. In effect, NS2 acts as a molecular decoy, sequestering UBL7 away from its legitimate partner on the mitochondrial membrane. This competitive mechanism is elegant in its simplicity: rather than degrading UBL7 or MAVS, the virus merely occupies a binding surface, diverting a host cofactor from its antiviral duty. Such competitive inhibition strategies are a recurring theme in viral immune evasion, and the identification of UBL7 as a target adds a new node to the map of host factors that influenza exploits or subverts.

To confirm that the effect observed in isolated protein interaction assays was meaningful during genuine infection, the team turned to cellular models of influenza infection using the PR8 strain, an H1N1 influenza A virus. When NS2 was knocked down during infection, cells that overexpressed UBL7 showed enhanced type I interferon signaling, indicating that removing the viral protein allowed the host cofactor to resume its stimulatory role. The same enhancement was seen in wild-type mouse embryonic fibroblasts, a standard laboratory cell type for innate immunity studies. Crucially, however, the enhancement disappeared in mouse embryonic fibroblasts in which the UBL7 gene had been knocked out. This genetic dependency is the strongest form of evidence that UBL7 is the relevant target: if NS2’s suppressive effect requires the presence of UBL7, then UBL7 must be the mediator through which NS2 exerts its inhibitory influence on interferon signaling.

The findings carry several implications for virology and immunology. First, they assign a novel immune evasion function to a viral protein whose role in antiviral immune evasion had been poorly understood. NS2 now joins the growing roster of influenza A virus proteins, including NS1, PB1-F2 and others, that contribute to the virus’s arsenal against innate immunity. Second, the study elevates UBL7 from a relatively obscure ubiquitin-like protein to a defined positive regulator of MAVS signaling, clarifying its position in the antiviral pathway and suggesting that other viruses may target it as well. Third, the work illustrates how a single viral protein can be multifunctional, combining a structural logistics role in the viral life cycle with an immunomodulatory role, a design principle that allows influenza to pack considerable functionality into a compact genome of only eight RNA segments.

From a broader perspective, the study deepens understanding of the interplay between influenza A virus and the host innate immune response, an arms race that has shaped both viral evolution and human susceptibility to disease. Every immune evasion mechanism the virus possesses represents a potential vulnerability that antiviral therapies could exploit. If the NS2-UBL7 interaction is required for efficient viral replication in the face of the interferon response, then molecules designed to block that interaction, or to stabilize the UBL7-MAVS axis, could theoretically restore a stronger early antiviral response in infected cells. The authors’ identification of the mechanistic interface, namely the competition between NS2 and MAVS for UBL7 binding, provides a concrete molecular target for such future exploration, although the current study is a basic research advance rather than a therapeutic development.

The research was conducted by teams based at the School of Life Sciences of Henan University in Kaifeng and the Henan Key Laboratory of Synthetic Biology and Biomanufacturing, together with collaborators at the CAS Key Laboratory of Pathogenic Microbiology and Immunology at the Institute of Microbiology, Chinese Academy of Sciences in Beijing. Xiaotian Yang, Junnan Shi and Xinyu Li contributed equally to the work, with Min Fang serving as senior corresponding author alongside Ruixue Xia and Wei Jiang. The project received sponsorship from the Natural Science Foundation of Henan Province and the National Natural Science Foundation of China, and the animal experimental protocol was approved by the Biomedical Research Ethics Committee of Henan University. The article is published open access under a Creative Commons Attribution 4.0 license, and the version shared in early access is citable with a permanent digital object identifier.

Taken together, the study delivers a clear mechanistic story: influenza A virus NS2 binds UBL7, competes with MAVS for that interaction, reduces K27-linked polyubiquitination of MAVS, and thereby suppresses type I interferon signaling, with the genetic knockout experiments confirming that none of this happens without UBL7 present. These findings provide new insights into how influenza disarms innate immunity and expand the catalog of host factors that the virus manipulates. As researchers continue to chart the full network of viral-host interactions, discoveries of this kind not only explain how the virus evades detection but also illuminate the normal wiring of the interferon pathway itself, knowledge that may ultimately inform the design of vaccines and antivirals aimed at tipping the balance back in favor of the host.

Subject of Research: Influenza A virus NS2-mediated inhibition of type I interferon signaling through UBL7 and MAVS

Article Title: Influenza A virus nonstructural protein 2 inhibits IFN-I signaling via competing with MAVS to bind to UBL7

Article References: Yang, X., Shi, J., Li, X., Chen, Y., Bi, K., Ji, W., Lu, Q., Song, X., Jiang, Z., Xu, H., Gu, X., Xia, R., Jiang, W., & Fang, M. (2026). Influenza A virus nonstructural protein 2 inhibits IFN-I signaling via competing with MAVS to bind to UBL7. Virology Journal. https://doi.org/10.1186/s12985-026-03316-w

Image Credits: AI Generated

DOI: 10.1186/s12985-026-03316-w

Keywords: influenza A virus, NS2 protein, UBL7, MAVS, type I interferon, innate immunity, immune evasion, K27-linked polyubiquitination, viral proteins, antiviral signaling, H1N1, virology