Veterinary Research最新文献

{"title":"Atlas of gross, histologic, and immunohistologic anatomy of the lymphoid system in Egyptian rousettes (Rousettus aegyptiacus).","authors":"Jessica A Elbert, Brian R Amman, Tara K Sealy, Patrick Atimnedi, Jonathan S Towner, Elizabeth W Howerth","doi":"10.1186/s13567-026-01786-y","DOIUrl":"10.1186/s13567-026-01786-y","url":null,"abstract":"<p><p>Chiropterans exhibit remarkable immunological adaptations that facilitate their function as competent reservoir hosts for diverse high-consequence zoonotic viruses while maintaining apparent clinical health. The Egyptian rousette (Rousettus aegyptiacus), a frugivorous pteropodid species, represents the sole confirmed natural reservoir for Marburg and Ravn viruses (family Filoviridae), yet comprehensive characterization of its lymphoid system architecture remains absent from the literature. This investigation presents the first systematic gross, histological, and immunohistochemical atlas of lymphoid tissues in this epidemiologically critical species, encompassing primary (bone marrow, thymus) and secondary lymphoid tissues (lymph nodes, spleen, mucosa-associated lymphoid tissue). Tissues from fetal, juvenile, and adult specimens were systematically evaluated to characterize age-related variations in lymphoid architecture and cellular composition dynamics. Immunohistochemical analyses employing cross-reactive antibodies against CD3, CD79a, Iba1, and Granzyme B elucidated the spatial distribution and organizational patterns of key lymphocyte populations and antigen-presenting cells across distinct lymphoid compartments. While overall lymphoid tissue organization demonstrated conservation relative to other mammalian species, several distinctive morphological features were identified, including prominently developed splenic marginal zones, extensive gut-associated lymphoid tissue networks, and organized nasopharyngeal and bronchial lymphoid structures. These anatomical specializations likely represent species-specific evolutionary adaptations underlying viral tolerance mechanisms and immunological equilibrium maintenance during persistent viral exposure. This comprehensive atlas provides an essential foundational resource for veterinary pathologists, comparative immunologists, and infectious disease investigators conducting research with R. aegyptiacus bat populations. By establishing anatomically and immunologically detailed reference standards for lymphoid tissues in this critical reservoir species, this work supports interpretation of experimental infection studies and may help guide future investigations of host-pathogen interactions, reservoir competence, and zoonotic spillover dynamics at wildlife-human interfaces.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13523375/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148841102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pseudorabies virus pUL40 drives inflammatory signaling through competitive hijacking of EphA2 from the Akt-EphA2 interaction.","authors":"Yutong Tian, Hang Yin, Jiaxiang Fu, Qingqing Yang, Ru Yan, Yuqing Li, Chao Ye, Rendong Fang","doi":"10.1186/s13567-026-01829-4","DOIUrl":"10.1186/s13567-026-01829-4","url":null,"abstract":"<p><p>Herpesvirus infection triggers excessive inflammation, contributing to tissue injury and disease severity, but the underlying drivers remain unclear. Here we identify EphA2 as a critical mediator of pseudorabies virus (PRV)-induced inflammatory response. Genetic or pharmacological inhibition of EphA2 reduced TNF-α production in PRV-infected cells and mice, alleviated liver and lung damage, and improved mice survival. Mechanistically, PRV infection promoted EphA2 phosphorylation at Ser-897, which activated NF-κB and MAPK pathways to drive TNF-α production. The PRV tegument protein UL40 directly bound the EphA2 kinase domain (residues 697-901), a region that also interacts with Akt. Unexpectedly, Akt acted as a negative regulator of inflammation, as its knockdown exacerbated cytokine production. UL40 competitively disrupted the constitutive EphA2-Akt complex in a time-dependent manner, relieving Akt-mediated restraint on EphA2 S897 phosphorylation. Accordingly, a UL40-deficient PRV mutant failed to enhance S897 phosphorylation, elicited lower inflammatory responses, and showed attenuated virulence in mice. Collectively, our findings reveal a proviral strategy whereby PRV UL40 hijacks EphA2 to counteract an intrinsic Akt-dependent inhibitory pathway. This UL40-EphA2-Akt cascade is a critical determinant of virus-induced inflammation, and EphA2 S897 represents a potential therapeutic target for mitigating alphaherpesvirus immunopathology.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13508209/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148819668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retraction Note: Astrocyte-derived MMP-9 is a key mediator of pseudorabies virus penetration of the blood-brain barrier and tight junction disruption.","authors":"Ying Zhang, Xianghua Shu, Ying Zhang, Chunlian Song, Yi Wu, Kesi Cui, Xue Zhang, Yalong Sun, Hong Shen, Qianfei Wei, Jianqin Li, Yue Shu","doi":"10.1186/s13567-026-01826-7","DOIUrl":"10.1186/s13567-026-01826-7","url":null,"abstract":"","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13504781/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148814291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transcriptomic analysis of naturally occurring bovine respiratory disease in Australian feedlot cattle identifies bovine viral diarrhoea virus-induced immunosuppression and Mollicutes as the dominant drivers of lung inflammation.","authors":"Gebremeskel Mamu Werid, Farhid Hemmatzadeh, Darren Miller, Milton M McAllister, Darren J Trott, Kiro Petrovski","doi":"10.1186/s13567-026-01813-y","DOIUrl":"https://doi.org/10.1186/s13567-026-01813-y","url":null,"abstract":"<p><p>Bovine respiratory disease (BRD) is the most economically significant syndrome of feedlot cattle worldwide, yet the relative contributions of individual BRD pathogens to host transcriptional responses remain poorly understood. We performed pathogen-stratified transcriptomic analysis of lung tissue obtained from naturally occurring BRD cases (n = 22) and non-BRD controls (n = 9) in feedlot cattle. BRD-affected tissue showed significant immune activation with 3148 differentially expressed genes (DEGs; 18.7% of the 16,873 genes tested), of which 70.4% were upregulated. Pathogen-stratified analysis revealed significant heterogeneity in host response (221-2241 DEGs per pathogen). Bovine viral diarrhoea virus (BVDV) was associated with a distinct immunomodulatory signature (79% of genes downregulated), consistent with its immunosuppressive role. Mollicutes showed the strongest transcriptional overlap with the core BRD signature: Mycoplasmopsis arginini, Metamycoplasma alkalescens and Metamycoplasma canadense shared 53-71% of their differentially expressed genes with the core BRD signature with 100% directional concordance, whereas Mycoplasmopsis bovis showed lower overlap (34%) despite near-ubiquitous detection (87.1%). Mycoplasmopsis arginini induced the largest transcriptional footprint (2241 DEGs), with 1316 genes (58.7%) overlapping the core BRD signature, representing 41.8% of all BRD DEGs, suggesting it may have an important role in BRD pathogenesis. Pasteurella multocida and Histophilus somni ranked among the top three in the integrated analysis, accounting for 77% of dose-responsive gene associations with load-dependent inflammatory amplification. It is hypothesised that in naturally occurring BRD in feedlots, BVDV was associated with suppressed host immunity; Mollicutes were associated with the core inflammatory transcriptome; and Gram-negative bacteria were associated with amplified host response proportionally to the bacterial load. These findings provide an important rationale for future diagnosis, treatment, prevention and control of BRD in Australian feedlots.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13483418/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148798368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Host-parasite cross-species regulation by Schistosoma japonicum EV-miRNA sja-miR-2a-3p limits hepatic fibrosis via BCL2 suppression in hepatic stellate cells.","authors":"Bowen Dong, Danlin Zhu, Junhan Xiong, Yuanzhao Sun, Ruiting Zhang, Zhiqiang Fu, Jinming Liu, Haoran Zhong, Yamei Jin","doi":"10.1186/s13567-026-01794-y","DOIUrl":"https://doi.org/10.1186/s13567-026-01794-y","url":null,"abstract":"<p><p>Schistosomiasis remains an important zoonotic parasitic disease, and hepatic fibrosis is a major cause of chronic pathology following Schistosoma japonicum infection. In schistosomiasis, hepatic fibrosis is the major cause of severe pathological damage. However, during the long-term co-evolution and coexistence between Schistosoma parasites and their hosts, the parasite can modulate the host hepatic fibrotic process through extracellular vesicle (EV)-mediated cross-species communication. In this study, we identified an EV-derived microRNA from Schistosoma japonicum, sja-miR-2a-3p, that suppresses hepatic pathology in the host. Using transwell co-culture and EV-isolation experiments, we confirmed that the helminth-specific sja-miR-2a-3p could be transferred to hepatic stellate cells (HSCs) via EVs. Bioinformatic and dual-luciferase assays revealed that host BCL2, a major anti-apoptotic gene, is a direct target of sja-miR-2a-3p. In vitro, sja-miR-2a-3p overexpression suppressed HSC proliferation and migration and induced mitochondrial dysfunction, caspase-3/-7/-9 activation, and apoptosis. In vivo, administration of sja-miR-2a-3p agomir to S. japonicum-infected mice significantly downregulated hepatic BCL2 expression, enhanced HSC apoptosis, alleviated granuloma formation, collagen deposition, and inflammation. Collectively, our findings reveal that schistosome EV-delivered sja-miR-2a-3p attenuates liver fibrosis by promoting mitochondrial apoptosis and functionally suppressing HSC activation. This study supports sja-miR-2a-3p as a candidate antifibrotic molecule.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13476918/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148761502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual-expression-site fowl adenovirus 4 (FAdV-4) with high viral titer: a promising viral vector for multivalent poultry vaccines.","authors":"Zhihui Tang, Wenjian Liu, Biao Xu, Dengfei Feng, Shuhui Liu, Wentao Fan, Suquan Song, Liping Yan","doi":"10.1186/s13567-026-01820-z","DOIUrl":"https://doi.org/10.1186/s13567-026-01820-z","url":null,"abstract":"<p><p>Fowl adenovirus serotype 4 (FAdV-4) is a nonenveloped double-stranded DNA virus with a 43-45 kb genome, making it a promising viral vector for developing multivalent poultry vaccines. However, limited genomic studies have hindered the design of strategies for generating recombinant FAdV-4 capable of expressing multiple foreign proteins while maintaining high viral titers. In this study, three deletion mutants (rD14AB, rD2042, rD19A) were generated to assess their roles in viral replication and pathogenicity. Only rD2042 showed impaired replication and virulence compared with wild-type FAdV-4. Foreign gene expression assays demonstrated that the D14AB site had a maximum insertion capacity of 2349 bp, and an SV40 poly(A) signal was required for efficient protein expression and viral propagation at this locus. In contrast, the D19A site tolerated insertions of up to 1257 bp in the absence of this signal. Using the insertion strategy optimized for wild-type CH_JS_2017, we modified the previously reported nonpathogenic rON1 strain (harboring the Hexon gene from the attenuated ON1 strain) to co-express mCherry, eGFP, and mTagBFP2 at the two independent sites. SPF chicken trials verified the safety of the engineered virus at immunization age and the genetic stability of exogenous genes. The recombinant virus maintained wild-type-comparable titers while carrying 3606 bp of total foreign sequences, highlighting its dual-site advantage and potential as a multivalent poultry vaccine vector.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13471547/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148766244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of the rock pigeon type IV interferon system reveals conserved tyrosine-based signaling via the IFN-υR1/IL10RB complex.","authors":"An Ning Pang, Jia Yi Li, Shan Nan Chen, Xiang Yang Wu, Nan Li, Lan Hao Liu, P Nie","doi":"10.1186/s13567-026-01823-w","DOIUrl":"10.1186/s13567-026-01823-w","url":null,"abstract":"<p><p>Type IV interferon (IFN), a recently identified class of IFN, exhibits broad-spectrum antiviral and antibacterial functions across species. In this study, the type IV IFN gene, IFN-υ, and its cognate receptor subunits (IFN-υR1 and IL10RB) were functionally characterized in an avian species, the rock pigeon (Columba livia). Phylogenetic analysis showed that rock pigeon IFN-υ, IFN-υR1, and IL10RB were clustered closely with their respective orthologs in other vertebrates. Expression profiling revealed the constitutive transcription of these genes across multiple tissues. Furthermore, the expression of these genes was significantly upregulated upon stimulation with the viral double-stranded RNA (dsRNA) mimic, poly(I:C). The recombinant rock pigeon IFN-υ activated the canonical Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway, inducing STAT1 phosphorylation and the consequent expression of key interferon-stimulated genes (ISGs) such as OAS1, PKR, and RSAD2. Using overexpression and knockdown assays, the biological activity of IFN-υ was found to signal through a heterodimeric receptor complex comprising IFN-υR1 and IL10RB. Importantly, two conserved tyrosine residues (Tyr₃₃₄ and Tyr₅₂₅) within the intracellular domain of IFN-υR1 were found essential for IFN-υ-mediated JAK-STAT pathway activation, ISG induction, and antiviral activity. These findings elucidate the conserved functional architecture and signaling mechanism of type IV IFN in vertebrates.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13466502/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148713729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infectious bursal disease virus induces GSDME-dependent pyroptosis via the mitochondrial caspase-9/3 pathway in DF-1 cells.","authors":"Liuyang Yuan, Hongchun Yang, Shuangshuang Ma, Aobo Xu, Shufeng Feng, Xiaoran Xuan, Shijun Xu, Songlin Yang, Kairu Wang, Gonghe Li, Hongbin Si, Jianni Huang, Yang Li, Changbo Ou","doi":"10.1186/s13567-026-01815-w","DOIUrl":"10.1186/s13567-026-01815-w","url":null,"abstract":"<p><p>Infectious bursal disease virus (IBDV) is an important avian pathogen that damages the bursa of Fabricius and continues to threaten the poultry industry. Pyroptosis is an inflammatory form of programmed cell death, but its contribution to IBDV-induced cellular injury remains incompletely defined. Here, using DF-1 cells, we found that IBDV infection was associated with caspase-3 activation, cleavage of gasdermin E (GSDME), generation of the pore-forming N-terminal fragment (GSDME-N), increased lactate dehydrogenase release, plasma membrane damage, and enhanced inflammatory cytokine-associated readouts, including increased interleukin (IL)-1β secretion and elevated IL-18 messenger RNA (mRNA) expression. IBDV infection also induced mitochondrial dysfunction, as evidenced by loss of mitochondrial membrane potential (ΔΨm), increased reactive oxygen species production, and activation of caspase-9, supporting the involvement of a mitochondria-associated caspase-9/3 pathway. Pharmacological inhibition of caspase-9 or caspase-3 reduced pyroptosis-associated readouts, indicating that mitochondrial damage contributes to IBDV-induced lytic cell death under the tested conditions. Expression of viral protein (VP)2 or VP5 alone caused detectable cytotoxicity but did not robustly reproduce GSDME cleavage, suggesting that viral proteins may contribute to upstream cellular stress that is further amplified during infection. Together, these findings support that IBDV engages a mitochondria-associated caspase-9/3-GSDME axis to promote pyroptosis-like lytic cell death in DF-1 cells.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13471472/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148727591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"WaaL-WaaP receptor cross-talk drives phage-induced collateral sensitivity to colistin in Salmonella Pullorum.","authors":"Mianzhi Wang, Yiwen Ren, Lei Jiang, Zixuan Wang, Peng Liu, Mingyi Zhang, Junxuan Zhang, Ruichao Li, Yongxue Sun, Zhiqiang Wang","doi":"10.1186/s13567-026-01825-8","DOIUrl":"10.1186/s13567-026-01825-8","url":null,"abstract":"<p><p>Phage therapy typically fails when bacteria rapidly evolve resistance, yet the inevitable fitness costs of escape mutants remain underexploited. In this study, an iterative and targeted phage-cocktail formulation strategy (ITPFS) was presented and developed. A potent lytic phage, PHZ055, was firstly isolated against a colistin-resistant Salmonella Pullorum strain. Co-cultured until resistant mutants emerged, a second lytic phage, PYW047_3, was screened for the resistant variant. The two phages were then combined as a cocktail. Results showed that bacterial growth was strongly suppressed and the emergence of resistance was markedly delayed. Receptor identification revealed that both phages use lipopolysaccharide (LPS) as a receptor, but at distinct sites: PHZ055 targets WaaL, and PYW047_3 targets WaaP. Mutation of WaaL was recently shown to be responsible for the loss of polymerized O-antigen units and thereby exposed the PYW047_3 binding region, indicating that phage cocktails targeting distinct receptor sites can be directionally screened. Moreover, mutants that escaped the two phages not only incurred a growth cost but also exhibited a 32-fold increase in colistin sensitivity. Combining the two phages together with 1/4 MIC colistin almost eradicated all bacteria within 24 h. In all, our study successfully provides a repeatable strategy that incorporates adaptive trade-offs to boost therapeutic efficacy.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13471373/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148722960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Host specificity and horizontal gene transfer in the MIB-MIP immunoglobulin evasion system in Mycoplasma gallisepticum.","authors":"Dilhani Ekanayake, Paola Vaz, Alistair R Legione, Nadeeka K Wawegama, Glenn F Browning, Kelly A Tivendale","doi":"10.1186/s13567-026-01779-x","DOIUrl":"10.1186/s13567-026-01779-x","url":null,"abstract":"<p><p>Mycoplasma gallisepticum is a major poultry pathogen responsible for chronic respiratory disease and substantial global economic losses. Its ability to establish chronic infections reflects its effective immune evasion strategies, but the mechanisms underlying this remain poorly understood. Some pathogenic mammalian mycoplasmas use the Mycoplasma Immunoglobulin Binding-Protease (MIB-MIP) system to capture and cleave host immunoglobulins (Ig), but the functionality and host-specificity of this system in M. gallisepticum have not been examined. We aimed to functionally characterise all the MIB-MIP homologues in M. gallisepticum and examine their host specificity. Five putative MIB and five putative MIP genes of M. gallisepticum were cloned, expressed as recombinant GST-fusion proteins, and purified for functional analysis. Immunoglobulin-binding assays showed that all MIB proteins bound both avian and mammalian immunoglobulins, forming stable MIB-Ig complexes, with distinct binding capacities. In contrast, proteolytic assays revealed that only three of the five MIP proteins could cleave avian immunoglobulins, when complexed with any of the five MIBs, generating characteristic Ig heavy-chain fragments. Only one MIP protease showed detectable interaction with mammalian immunoglobulins, indicating strong host specificity of these MIPs and functional specialisation for avian immunoglobulin-cleavage. These results revealed that MIB and MIP proteins of M. gallisepticum are adapted to cleavage of avian immunoglobins, thereby interfering with antibody-mediated host immune responses. Bioinformatic analysis suggested that MIB-MIP homologues are widespread among avian mycoplasmas that share similar hosts, tissue tropisms and transmission patterns, and detected evidence of horizontal gene transfer and recombination, indicating that there have been MIB-MIP evolutionary adaptations among the avian mycoplasmas.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13459921/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148713732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}