Background Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a group of chronic intestinal inflammatory disorders with diverse etiologies and limitations in current treatments. Trichinella spiralis, a foodborne parasitic nematode, has been reported to alleviate colitis in mouse models, but its specific mechanism remains unclear. Methods This study aims to investigate whether T. spiralis-induced autophagy can alleviate IBD by inhibiting the NLRP3 inflammasome. Experimental colitis was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in mice 21 days after T. spiralis infection. Experimental groups were treated with 3-methyladenine (3-MA, autophagy inhibitor), rapamycin (Rapa, autophagy activator), or MCC950 (NLRP3 inhibitor), respectively. The severity of enteritis, the levels of autophagy and NLRP3 inflammasome activity, were evaluated using colon length, body weight, disease activity index (DAI) scores, hematoxylin-eosin (H&E) staining, myeloperoxidase (MPO) activity assay, flow cytometry, qPCR, and Western blot. Results The results revealed that T. spiralis infection alleviated colitis, concurrent with enhanced autophagy and suppressed NLRP3 inflammasome activation. Notably, inhibition of autophagy led to aggravated colitis symptoms and concomitant activation of the NLRP3 inflammasome. In contrast, autophagy activation resulted in attenuated colitis manifestations and inhibition of the NLRP3 inflammasome. Moreover, direct inhibition of the NLRP3 inflammasome was capable of alleviating colitis. Conclusions This study reveals that T. spiralis can alleviate IBD by inducing autophagy to inhibit the NLRP3 inflammasome, providing new insights into the treatment of IBD.

Prolonged consumption of diets high in copper (Cu) leads to multiorgan copper accumulation in fattening pigs, resulting in a year-on-year increase in the incidence of clinical copper poisoning and posing a potential risk to human food safety. Gut probiotics have demonstrated potential for preventing and treating copper toxicity because of their ability to chelate heavy metal ions and maintain metabolic homeostasis. However, the mechanism of action remains poorly understood. Our study identified a strain of Bacillus amyloliquefaciens K309 isolated from pigs with significant copper ion absorption capacity. Supplementation with B. amyloliquefaciens K309 reduced blood and intestinal copper levels in weaned piglets but increased fecal copper excretion, thus alleviating intestinal barrier damage. Further investigations revealed that B. amyloliquefaciens K309 intervention promoted hepatic bile secretion and suppressed UCP2 expression. Moreover, luteolin, which was produced by the gut microbiota enriched after B. amyloliquefaciens K309 intervention, also alleviated symptoms in copper-intoxicated mice. Mechanistically, luteolin alleviates high copper-induced hepatocyte apoptosis by promoting the targeting of K48-linked polyubiquitination degradation of UCP2 by ASB4. These findings establish B. amyloliquefaciens K309 as a key microorganism for preventing and treating copper toxicity, revealing its dual novel functions of biosorption and metabolic regulation previously unreported for this strain.

Chicken coccidiosis caused by Eimeria tenella (E. tenella) poses a major threat to global poultry production, with its tropism for the caecal microenvironment and dynamic interactions with the resident microbiota remaining incompletely understood. The caecal microbiota plays a critical role in host‒parasite interplay, yet the mechanisms through which microbial homeostasis influences E. tenella development and host resistance remain elusive. This study aimed to elucidate the causal relationship between caecal dysbiosis and E. tenella pathogenesis, with a focus on identifying microbiota-derived regulators of parasite development and host immunity. Antibiotic-induced caecal dysbiosis (ABX) significantly impaired E. tenella macrogametogenesis, demonstrating microbiota-dependent regulation of parasitic development. Faecal microbiota transplantation (FMT) validated this causal link, revealing that microbial reconstitution restored parasite maturation. Notably, Intestinimonas spp. were identified as key inhibitors of E. tenella development through transcriptional regulation of the EtGFAT gene (Eimeria tenella glucosamine: fructose-6-phosphate aminotransferase), a critical mediator of macrogamete formation. Furthermore, the transplantation of Intestinimonas butyriciproducens (I. butyriciproducens) attenuated clinical manifestations of infection while increasing IFN-γ secretion from CD8+ T lymphocytes, thereby enhancing host resistance to E. tenella. This study revealed that caecal microbiota homeostasis is indispensable for E. tenella developmental progression and highlights Intestinimonas as a pivotal microbial regulator of parasite biology. The dual role of I. butyriciproducens in suppressing parasitic virulence and potentiating adaptive immune responses underscores the therapeutic potential of microbiota-targeted strategies. These findings provide a foundation for the development of novel anticoccidial interventions through targeted manipulation of caecal microbial communities.

Coccidiosis has resulted in substantial economic losses in the poultry industry. The prevalence and severity of drug resistance to anticoccidial agents have exacerbated the challenges associated with controlling coccidiosis. Consequently, exploring novel drug targets is crucial for the prevention and treatment of coccidiosis. In this study, we performed acetylation modification proteomics on the sporozoites and merozoites of Eimeria tenella during the asexual stage. Moreover, the anticoccidial efficacy of histone deacetylase (HDAC) inhibitors was evaluated both in vitro and in vivo. In total, 341 differentially acetylated proteins and 558 differentially acetylated modification sites were identified. Histones H2A, H2B, H2B variants, H3, and H4 are all acetylated and have multiple acetylation sites, suggesting that acetylation plays important roles in the gene regulation, replication, and development of E. tenella. KEGG pathway analysis revealed that glycolysis/gluconeogenesis pathway was enriched. Glycolysis is the main mode of energy metabolism in Apicomplexa. In the glycolysis pathway, eight key enzymes are downregulated by acetylation and have multiple acetylation sites. It has been suggested that histone deacetylase (HDAC) is the target of anticoccidial action. Trichostatin A (TSA, an inhibitor of HDAC family deacetylases) and nicotinamide (NAM, an inhibitor of SIRT family deacetylases) can inhibit sporozoite invasion (P ≤ 0.01) and promote sporozoite apoptosis (P ≤ 0.05). Intraperitoneal injection of TSA and NAM can reduce chicken caecal lesions and oocyst shedding, and the anticoccidial index can reach 143. This study is the first to investigate the anticoccidial effect of deacetylase inhibitors, providing a new strategy for the prevention and control of coccidiosis.

Salmonellosis is a global foodborne pathogen with zoonotic importance that seriously threatens livestock breeding and human health. Due to the implementation of an anti-resistance policy, probiotics as an alternative to antibiotics have attracted widespread attention. In this study, the widely used probiotic Escherichia coli Nissle 1917 (EcN) was selected to study its protective effect on mice infected with Salmonella typhimurium. Two mice groups (n = 15) were treated with either EcN and PBS. Flow cytometry showed that the frequency of mature dendritic cells in the Peyer's patch was significantly increased compared to the PBS group. Previous administration of EcN protected against challenge with Salmonella typhimurium infection as an increased survival rate of the mice, a decreased degree of pathological changes, and the number of live bacteria in the spleen and liver were recorded compared to the control group. The results of 16S rRNA high-throughput sequencing of fecal microbial flora showed that EcN could reduce the abundance of microorganisms in the intestine and reduce the proportion of Lactobacillus, while Ruminococcaceae sp., Rikenella sp. and Bifidobacterium sp. disappeared. In contrast, the abundance of Bacteroides increased, which reduced the effect of Salmonella typhimurium on the distribution of intestinal microorganisms. Our results demonstrated that EcN has a protective effect against Salmonella typhimurium infection and may act as a candidate probiotic bacterium to apply in the future.

Enteropathogenic Escherichia coli (EPEC) infection remains a major cause of intestinal barrier dysfunction and diarrhea, necessitating the development of novel non-antibiotic therapies. While Pediococcus pentosaceus (P. pentosaceus) exhibits probiotic potential, the specific role of its postbiotic components, particularly extracellular vesicles (EVs), in host-pathogen interactions remains obscure. In this study, we systematically evaluated the protective efficacy and underlying mechanisms of P. pentosaceus DF29 (DF29) and its derived EVs (PpEVs) against EPEC-induced enteritis. Characterization revealed that PpEVs isolated via ultracentrifugation exhibited a typical vesicular morphology, high purity, and robust stability under simulated gastrointestinal conditions. In vitro, PpEVs were efficiently internalized by macrophages and significantly blunted EPEC-induced pro-inflammatory responses. In vivo, oral administration of PpEVs recapitulated the protective effects of live DF29, including alleviating body weight loss, reducing disease activity index, and restoring histological integrity. Crucially, PpEVs reinforced the intestinal barrier by upregulating tight junction proteins, mitigating oxidative stress, and rebalancing the dysbiotic gut microbiota. Mechanistically, we demonstrated that PpEVs exerted their anti-inflammatory effects by inhibiting the TLR4/MyD88/NF-κB signaling axis, thereby shifting macrophage polarization from an M1 proinflammatory to an M2 anti-inflammatory phenotype and rectifying the Th1/Th2 and Th17/Treg imbalances. Collectively, our findings suggest that PpEVs represent a potential intervention strategy to preserve intestinal homeostasis and counteract EPEC-associated inflammation.

The current seasonal influenza vaccine is only 20%-60% effective on average, and its protective effect lasts only 6-8 months. Additionally, some viruses are prone to antigenic drift, which prevents the vaccine from being fully effective. Furthermore, due to antigenic drift, they are unable to effectively address the threat of pandemics, continuing to pose a threat to global health. There is an urgent need to develop vaccine strategies that go beyond traditional vaccines. The human adenovirus type 5 (Ad5) vector is biologically safe and capable of inducing strong systemic and mucosal immune responses. Currently, the Ad5 vector is widely utilized in vaccine development against various pathogens. Here, we developed and evaluated an adenovirus-based influenza vaccine (rAd5-GFP-RBS). This vaccine focuses on the receptor-binding site (RBS) of hemagglutinin. The vaccine was delivered intranasally to C57BL/6J mice and induced robust systemic and mucosal immune responses, evidenced by significantly higher IgG levels in serum and bronchoalveolar lavage fluid. Notably, the IgG antibody titer in the alveolar lavage fluid of the rAd5-GFP-RBS group was significantly higher than that in the PBS group (∗∗∗p < 0.001). Following H1N1 PR8 challenge, vaccinated mice exhibited significantly enhanced survival, significantly reduced weight loss, and decreased lung pathology compared to controls. Histopathology and immunohistochemistry confirmed lower viral antigen levels in vaccinated mice. Measured influenza-specific antibodies demonstrated strong immune response, highlighting the vaccine's potential for excellent protective immunity. These findings support rAd5-GFP-RBS as promising candidate for influenza protection, providing a platform for rapid vaccine development against emerging strains. Further optimization could improve vaccine durability and efficacy.

Autophagy-associated protein 13 (ATG13) plays a pivotal role in regulating the assembly of the autophagy initiation complex. However, the function and mechanism of action of ATG13 during influenza virus infection remain incompletely understood. This study elucidates that ATG13 restricts influenza A virus (IAV) replication while potentiating the activation of the type I interferon (IFN-I) pathway. Mechanistically, coimmunoprecipitation assays revealed that ATG13 interacts with MAVS and recruits the E3 ubiquitin ligase ASB1 to catalyze K63-linked polyubiquitination at the K348 residue, thereby amplifying the downstream antiviral signaling cascade. Furthermore, through dual-luciferase reporter assays and pharmacological inhibition of autophagy, we confirmed that this novel immunomodulatory function of ATG13 is independent of the canonical autophagy pathway. The present study identifies ATG13 as a novel host restriction factor against IAV and reveals a nonautophagic role for ATG13 in antiviral innate immunity.

Rotavirus (RV) infection is a zoonotic disease that causes severe diarrhea in young mammals and humans and is spreading globally. The TLR3/TRIF and RIG-I/MAVS signaling pathways are activated upon recognition of double-stranded RNA (dsRNA) and play crucial roles in the host antiviral response during RV infection. However, the mechanism by which RV induces B-cell immune responses through TLR3 and RIG-I signaling remains unclear. Here, T-cell receptor (TCR) sequencing results revealed that TRIF gene deletion affects the frequency of complementarity-determining region 3 (CDR3) clones recognizing antigen peptides presented by MHC-II on B cells and the utilization of V and J genes in mouse CD4+ T cells. Specifically, a reduced frequency of germinal center (GC)-activated B cells was observed in the mesenteric lymph nodes (MLNs) of TLR3-/-, TRIF-/-, and MAVS-/- mice. Similarly, the levels of antibodies secreted by B cells in serum and CD138+IgA+ cells in the small intestine decreased. The simultaneous absence of the TLR3 and MAVS genes weakened the proliferative capacity of B cells. This study elucidates the mechanism by which RV regulates B-cell immunity through the TLR3/TRIF and MAVS signaling pathways, providing theoretical basis for novel vaccine development.

N6-methyladenosine (m6A) is a major post-transcriptional RNA modification, and the demethylase ALKBH5 has emerged as a versatile but highly context-dependent regulator of RNA fate. This review integrates current evidence showing that ALKBH5 links epitranscriptomic control to cellular stress adaptation, genome maintenance, immune-cell function, viral infection, and therapeutic response. In DNA damage and cell-cycle regulation, ALKBH5 modulates checkpoint, repair, and apoptotic pathways, thereby influencing genome stability and sensitivity to radiotherapy or chemotherapy. In immune biology, it shapes γδ T-cell development, CD4+ T-cell pathogenicity, CD8+ T-cell infiltration, and tumor-immune crosstalk. In host-pathogen interactions, ALKBH5 can either enhance antiviral defense or promote viral persistence and latency, including HIV-1 reactivation, depending on the regulated transcript network. We propose that the biological output of ALKBH5 is determined by target transcript identity, cellular context, reader environment, and upstream regulatory signals. This framework positions ALKBH5 as both a mechanistic hub and a context-guided therapeutic target.

Pseudorabies virus (PRV) infects a wide range of mammals and poses a potential threat to human health. The stimulator of interferon genes (STING) is crucial for innate immunity against DNA viruses and intestinal homeostasis; however, its influence on gut microbiota-mediated antiviral immunity is unclear. Here, we demonstrate that deletion of the STING gene or the IFNAR1 gene in mice aggravates PRV-induced lung pathology, increases viral load and inflammatory cytokine expression, reduces type I interferon transcription, and ultimately decreases survival of STING-KO mice and IFNAR1-KO mice. Additionally, STING deficiency causes rapid loss of alveolar macrophages (AMs) in the lungs following PRV infection, promotes neutrophil and monocyte recruitment through activation of inflammation-related signaling pathways, and disrupts the pulmonary immune cell balance. Furthermore, STING-deficient mice exhibit a markedly reduced abundance of Ligilactobacillus murinus (L. murinus) in the gut after PRV infection, and the level of 5-hydroxyindole (5-HI) correlates positively with intestinal Ligilactobacillus abundance. L. murinus modulates gut microbiota-derived 5-hydroxyindole. Moreover, L. murinus and 5-HI protect antibiotic (Abx)-treated mice from PRV infection by activating the aryl hydrocarbon receptor (AhR) in a STING-dependent manner, and this protective effect is abolished in Ahr-/- mice. Collectively, these findings highlight that STING inhibits PRV infection by regulating L. murinus and 5-HI, which leads to activation of AhR.

Gut microbiome dysbiosis causes various intestinal diseases. However, an undefined composition and potential biosafety risks limit the applicability of traditional fecal microbiota transplantation (FMT). Synthetic microbial communities (SynComs), which are compositionally defined and rationally designed emerging live biotherapeutics, offer a novel alternative to FMT. This review establishes strict boundaries between SynComs and traditional donor-derived preparations, comparatively evaluating “top-down” and “bottom-up” construction strategies. We explored the mechanisms underlying the SynComs-mediated synergistic restoration of intestinal homeostasis via direct targeted antagonism and modulation of the host immune network. Moreover, we systematically evaluated the current research landscape of SynComs in Clostridioides difficile infection, inflammatory bowel disease, and colorectal cancer. This review examines fundamental challenges, including host colonization resistance, chemistry, manufacturing, and control barriers, biosafety risks, and microbiokinetic regulatory frameworks, thereby addressing the translational gap. Our analysis of current literature provides a theoretical basis for the clinical translation of SynComs as emerging live biotherapeutics.

The swine is considered an important host for the production of pandemic influenza viruses, and studying the immune characteristics of swine influenza virus (SIV) infection in piglets is crucial for pandemic prevention. Here, we used single-cell sequencing (scRNA-seq) to demonstrate that Genotype 4 (G4) reassigned Eurasian avian-like (EA) H1N1 SIV and H9N2 avian influenza virus (AIV) infection caused significant changes in immune cell composition, gene expression and cell communication. Our study revealed that H1N1 SIV elicits a stronger immune response, and the number of T cells, especially CD8+ T cells, is significantly reduced by infection. Additionally, H1N1 SIV enhanced part of the intercellular communication, especially triggering the T cell-involved transforming growth factor-β (TGF-β) signaling pathway network, in which the activation of TGF-β3 ligand receptor signaling is a key regulator. Moreover, flow cytometry and ELISA analysis revealed that H1N1 SIV infection resulted in an increase in TGF-β3 derived from CD4+ and CD8+ T cells, and TGF-β3 is very important to maintain the balance of CD8+ T cell function. The loss of CD8+ T cells can slow weight loss and lung inflammation in the early stage of infection but also affects recovery in the later stage of infection. Overall, these results revealed the presence of TGF-β3, which is rarely mentioned in SIV infection, and elucidated its importance in maintaining the balance of CD8+ T cell function during infection. This study reveals the effects of H1N1 SIV infection on the composition and function of immune cells, and provides new insights into the prevention and treatment of SIV and the prevention of human pandemics.

The Porcine Epidemic Diarrhea Virus (PEDV) is one of the major challenges facing the global pig farming industry, and vaccines and treatments have proven difficult in controlling its spread. Faecalibacterium prausnitzii (F.prausnitzii), a key commensal bacterium in the gut, has been recognized as a promising candidate for next-generation probiotics due to its potential wide-ranging health benefits. A decrease in F.prausnitzii abundance has been associated with certain viral infections, suggesting its potential application in preventing intestinal viral infections. In this study, we utilized a piglet model to examine the potential role of F.prausnitzii in PEDV infections. A piglet model of PEDV infection was established and supplemented with F.prausnitzii, revealing that F.prausnitzii mitigated PEDV infection. Further studies found that outer membrane vesicles (OMVs) are the main functional components of F.prausnitzii, and proteomics, untargeted metabolomics, and small RNA-seq were used to analyze the composition of OMVs. Exhaustion of the gut microbiota demonstrated that the function of Fp. OMVs relies on the presence of the gut microbiota. Additionally, metagenomic analysis indicated that Fp. OMVs altered the gut microbiota composition, enhancing the abundance of Faecalibacterium prausnitzii, Prevotellamassilia timonensis, and Limosilactobacillus reuteri. Untargeted metabolomics analysis showed that Fp. OMVs increased phosphatidylcholine (PC) levels, with PC identified as a key metabolite in alleviating PEDV infection. Single-cell sequencing revealed that PC altered the relative abundance of intestinal cells, increased the number of intestinal epithelial cells, and reduced necroptosis in target cells. PC treatment in infected IPEC-J2 and Vero cells alleviated necroptosis and reduced the activation of the RIPK1-RIPK3-MLKL signaling axis, thereby improving PEDV infection. F.prausnitzii and its OMVs play a critical role in mitigating PEDV infections. These findings provide a promising strategy to ameliorate PEDV infection in piglets.

H9N2 influenza virus infections represent a significant respiratory health concern, yet the functional role of gut microbiota during infection progression remains poorly understood. Here, we show that H9N2 infection causes dose-dependent alterations in gut microbial communities in a mammalian infection model, particularly the depletion of Prevotella species. Prophylactic administration of Prevotella copri improved survival and clinical outcomes in infected mice by restructuring the gut microbiome, promoting beneficial bacteria, and suppressing pathogens. Metabolomic profiling revealed increased isovaleric acid levels in the intestine and serum. Isovaleric acid pretreatment reduced pulmonary inflammation, alleviated tissue damage, and preserved epithelial integrity. Isovaleric acid pretreatment alleviates lung inflammation, reduces tissue damage, and maintains epithelial integrity. Additionally, isovaleric acid mitigates infection caused by the H1N1 influenza virus. These findings highlight the immunomodulatory role of gut commensals and their metabolites in antiviral defense, offering a new approach to influenza virus treatment.

The innate immune system serves as the first line of defense for the host against microbial invasion. Toll-like receptors (TLRs), are pathogen pattern recognition receptors can initiate signal cascades to mediate innate immune responses; however, the mechanism of TLR2 in viral infections remains unclear. This study aimed to clarify the impact of TLR2 deficiency on the pathogenesis of Porcine Epidemic Diarrhea Virus (PEDV) infection and host immune defense. Through transcriptome analysis, the abnormal molecular expression profiles induced by TLR2 deficiency in PEDV-infected bone marrow-derived dendritic cells (BMDCs) was characterised, including aberrant activation of the non-canonical nuclear factor-kappa B (NF-κB) signaling pathway, dysregulated expression of MHC Class Ⅰ/Ⅱ genes, and disordered apoptotic signaling. To verify the effects of these molecular characteristics on cellular functions, further detection using flow cytometry revealed the following: in terms of maturation and activation, TLR2 deficiency significantly reduced the surface levels of CD40+, CD86+, and CD83+ in PEDV-infected BMDCs (p < 0.05); regarding antigen-presenting function, IFN-γ+ expression was significantly downregulated in CD4+/CD8+ T cells co-cultured with TLR2-deficient BMDCs (p < 0.05). The level of late apoptosis in TLR2-deficient BMDCs was significantly increased (p < 0.05). In summary, TLR2 deficiency can lead to defects in maturation and activation, impaired antigen-presenting function, and enhanced apoptosis in PEDV-infected BMDCs, a process that may be associated with the aberrant activation of the non-canonical NF-κB pathway mediated by TLR2 deficiency. This study provides new insights at the molecular and cellular levels for elucidating the role of TLR2 in PEDV infection and host immune defense.

Canine parvovirus type 2 (CPV-2) causes an acute and highly transmissible disease characterized by severe hemorrhagic enteritis and myocarditis, ultimately resulting in the death of dogs and wild carnivores. At present, although vaccines have been developed for CPV-2, there are no specific and effective vaccines available for prevention of CPV-2c infection. To develop mucosal vaccines against CPV-2c, we constructed recombinant Lactobacillus plantarum (L. plantarum) expressing the VP2 antigen of CPV-2c. We amplified the VP2 gene from a CPV-2c subtype strain and subsequently constructed recombinant L. plantarum NC8 strains that express the VP2 and pgsA'-VP2 proteins, respectively. This work has shown that recombinant L. plantarum strains NC8/pSIP409-VP2 and NC8/pSIP409-pgsA'-VP2 can effectively activate dendritic cells maturation markers (CD80, CD86, and MHC-Ⅱ) while inducing robust IgG and IFN-γ responses in both mice and dogs. Furthermore, recombinant L. plantarum elevated sIgA and IgG concentrations and augmented B220⁺IgA⁺ cell populations. The data indicated that the recombinant L. plantarum developed in this work can significantly enhance the host immunity as an oral vaccination and may contribute to the prevention and control of canine parvovirus infection in dogs.

Enterococcus durans is a potential probiotic with beneficial for the health of people and animals. However, the understanding of the antioxidant activity of E. durans is limited. In this study, the antioxidant activity of E. durans isolate J396 was investigated. The strain was well tolerant to heat stress and showed extensively resistant to acid and bile salts. In vitro, the DPPH radical scavenging ability of J396 was 89.95%. Feeding of Caenorhabditis elegans with J396 did not affect nematodes growth and reproduction, and significantly prolonged the lifespan of the nematodes. In addition, the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-px), and total antioxidant capacity (T-AOC) activities increased by 57.05%, 36.25%, 82.88%, and 49.96%, respectively. The malondialdehyde (MDA), lipofuscin, and reactive oxygen species (ROS) levels were reduced by 28.40%, 28.72%, and 65.57%, respectively. E. durans J396 effectively protected C. elegans from hydrogen peroxide-induced oxidative stress damage. The activity of SOD, CAT, GSH-px, and T-AOC increased by 142.03%, 74.86%, 62.01%, and 94.16%, respectively. Feeding E. durans J396 to C. elegans decreased MDA, lipofuscin, and ROS by 33.59%, 19.70%, and 56.42%, respectively. RT-qPCR analysis showed that the feeding of C. elegans with J396 upregulated the expressions levels of nsy-1, pmk-1, skn-1, and sod-3 in C. elegans. Our study confirmed the antioxidant properties of E. durans J396, indicating its potential application in the pharmaceutical industry and the antioxidant therapy for animals.

Newcastle disease virus (NDV) is a significant enveloped virus within the Paramyxoviridae family, posing a major threat to the global poultry industry. Increasing evidence suggests that cholesterol-25-hydroxylase (CH25H) and its enzymatic product, 25-hydroxycholesterol (25HC), exhibit broad-spectrum antiviral activity properties by modulating lipid metabolism and various signaling pathways. However, the specific role of CH25H in regulating NDV infection and replication remains unclear. In this study, we demonstrate that CH25H significantly inhibits NDV replication by blocking viral entry through its enzymatic product, 25HC. Notably, a catalytic mutant of CH25H (CH25H-M), which lacks hydroxylase activity, still retains partial ability to inhibit NDV replication, suggesting the involvement of an enzyme-independent antiviral mechanism. Furthermore, we found that CH25H interacts with the viral nucleoprotein (NP), leading to a reduction in NP expression and inhibition of viral ribonucleoprotein (RNP) complex activity. These findings reveal that CH25H exerts antiviral effects through both enzyme-dependent and -independent mechanisms, providing new insights into its role in host defense and offering potential targets for the development of antiviral therapies.IMPORTANCECholesterol 25-hydroxylase (CH25H) is a multifunctional host protein that has been implicated in regulating the life cycles of various viruses. As a prototype of paramyxovirus, Newcastle disease virus (NDV) poses a significant threat to the global poultry industry, causing substantial economic losses. Uncovering the mechanisms of NDV-host interactions is crucial for unraveling the viral pathogenesis and the host immune response, which can drive the development of effective antiviral therapies. Here, we demonstrate that CH25H, whose expression is induced upon NDV infection, plays a pivotal role in restricting viral replication. Specifically, CH25H interacts with the viral NP and inhibits the viral RNP activity. These findings expand our understanding of CH25H's antiviral functions and offer new insights into virus-host interactions, providing potential targets for the development of novel antiviral drugs against NDV and related pathogens.

Trichinella spiralis infection is a serious parasitic zoonosis in which a collagenous capsule surrounding the larva is developed in the striated muscle cells. However, the mechanism of T. spiralis encapsulation is currently poorly understood. It has been reported that T. spiralis infection can induce the production of IL-13 via the NLRP3 inflammasome, and it has also been suggested IL-13 thus produced may be involved in T. spiralis encapsulation. This research aimed to clarify the involvement of NLRP3 and IL-13 in the T. spiralis capsule formation process. IL- 13 and NLRP3 inhibitors were used in a T. spiralis infected mouse model and in C 2 C 12 cells to analyze the role of IL-13 and NLRP3 in encapsulation. The results showed that T. spiralis infection significantly increased the expression levels of IL-13 and collagen IV and VI. The production of collagen around the T. spiralis encapsulation zone was significantly inhibited when an IL-13 inhibitor was applied. Moreover, the expression levels of IL-13 and collagen IV and VI were significantly decreased by the NLRP3 inhibitor in vitro and in vivo. The above results indicated that NLRP3 can participate in the development of T. spiralis encapsulation by regulating IL-13 expression and stimulating collagen IV and VI synthesis during T. spiralis infection.