Veterinary microbiology最新文献_第9页

NSP9 is a key virulence determinant in highly pathogenic PRRSV-mediated thymic injury via synergistic activation of apoptotic and metabolic pathways 在高致病性prrsv介导的胸腺损伤中，NSP9是一个关键的毒力决定因素，通过凋亡和代谢途径的协同激活。

IF 2.7 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2026-02-01 Epub Date: 2025-12-31 DOI: 10.1016/j.vetmic.2025.110868

Fanliang Meng , Chenchen Cui , Xinyi Huang , Qianru Zhang , Longshuai Yao , Xuehui Cai , Tongqing An , Gang Wang

Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) induces severe thymic atrophy, contributing to immunosuppression in infected piglets. This study investigated the roles of viral nonstructural proteins NSP9 and NSP10 in thymic pathogenesis using chimeric viruses (HC9 and HC10) generated by replacing NSP9/NSP10 of the HP-PRRSV HuN4 strain with those from the classical CH-1a strain. In vitro replication was significantly affected by these swaps, with NSP9 showing a more pronounced effect. In vivo replication kinetics, pathogenicity, and thymus damage were analyzed in piglets inoculated with the HuN4 strain or the chimeric strains. The study found that NSP9 and NSP10 are closely associated with PRRSV replication efficiency and pathogenicity, with NSP9 having a greater impact on thymus atrophy and both NSP9 and NSP10 playing a key role in inducing thymocytes apoptosis. Transcriptomic analysis revealed that HuN4 infection significantly upregulated genes associated with apoptosis, inflammatory responses, and metabolic pathways (e.g., NF-κB, PI3K-Akt, and p53 signaling), while HC9 showed attenuated effects. Flow cytometry confirmed HuN4-induced depletion of CD4⁺CD8⁺ thymocytes and dysregulated surface marker expression (CD4). TUNEL assays and apoptosis-related gene profiling further implicated NSP9 in activating both intrinsic and extrinsic apoptotic pathways. Notably, metabolic pathway enrichment suggested crosstalk between apoptosis and energy sensing (e.g., AMPK-mTOR). These findings highlight NSP9 as a critical virulence factor driving thymic atrophy through synergistic immune hyperactivation, apoptotic cascades, and metabolic reprogramming, providing novel insights for PRRSV vaccine design and immunomodulatory strategies.

高致病性猪繁殖与呼吸综合征病毒（HP-PRRSV）引起仔猪严重胸腺萎缩，导致仔猪免疫抑制。本研究利用HC9和HC10嵌合病毒将HP-PRRSV HuN4株的NSP9/NSP10替换为经典CH-1a株的NSP9/NSP10，研究了病毒非结构蛋白NSP9和NSP10在胸腺发病中的作用。这些交换显著影响了体外复制，其中NSP9表现出更明显的影响。研究了HuN4株和嵌合株接种仔猪的体内复制动力学、致病性和胸腺损伤情况。研究发现，NSP9和NSP10与PRRSV的复制效率和致病性密切相关，其中NSP9对胸腺萎缩的影响更大，NSP9和NSP10在诱导胸腺细胞凋亡中都起着关键作用。转录组学分析显示，HuN4感染显著上调了与凋亡、炎症反应和代谢途径相关的基因（如NF-κB、PI3K-Akt和p53信号传导），而HC9的作用减弱。流式细胞术证实了hun4诱导的CD4+CD8+胸腺细胞耗竭和表面标记物表达失调（CD4）。TUNEL实验和凋亡相关基因谱进一步表明，NSP9在激活内源性和外源性凋亡通路中都有作用。值得注意的是，代谢途径的富集表明细胞凋亡和能量感应（如AMPK-mTOR）之间存在串扰。这些发现强调了NSP9是通过协同免疫超激活、凋亡级联和代谢重编程驱动胸腺萎缩的关键毒力因子，为PRRSV疫苗设计和免疫调节策略提供了新的见解。

{"title":"NSP9 is a key virulence determinant in highly pathogenic PRRSV-mediated thymic injury via synergistic activation of apoptotic and metabolic pathways","authors":"Fanliang Meng , Chenchen Cui , Xinyi Huang , Qianru Zhang , Longshuai Yao , Xuehui Cai , Tongqing An , Gang Wang","doi":"10.1016/j.vetmic.2025.110868","DOIUrl":"10.1016/j.vetmic.2025.110868","url":null,"abstract":"<div><div>Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) induces severe thymic atrophy, contributing to immunosuppression in infected piglets. This study investigated the roles of viral nonstructural proteins NSP9 and NSP10 in thymic pathogenesis using chimeric viruses (HC9 and HC10) generated by replacing NSP9/NSP10 of the HP-PRRSV HuN4 strain with those from the classical CH-1a strain. <em>In vitro</em> replication was significantly affected by these swaps, with NSP9 showing a more pronounced effect. <em>In vivo</em> replication kinetics, pathogenicity, and thymus damage were analyzed in piglets inoculated with the HuN4 strain or the chimeric strains. The study found that NSP9 and NSP10 are closely associated with PRRSV replication efficiency and pathogenicity, with NSP9 having a greater impact on thymus atrophy and both NSP9 and NSP10 playing a key role in inducing thymocytes apoptosis. Transcriptomic analysis revealed that HuN4 infection significantly upregulated genes associated with apoptosis, inflammatory responses, and metabolic pathways (e.g., NF-κB, PI3K-Akt, and p53 signaling), while HC9 showed attenuated effects. Flow cytometry confirmed HuN4-induced depletion of CD4<sup>+</sup>CD8<sup>+</sup> thymocytes and dysregulated surface marker expression (CD4). TUNEL assays and apoptosis-related gene profiling further implicated NSP9 in activating both intrinsic and extrinsic apoptotic pathways. Notably, metabolic pathway enrichment suggested crosstalk between apoptosis and energy sensing (e.g., AMPK-mTOR). These findings highlight NSP9 as a critical virulence factor driving thymic atrophy through synergistic immune hyperactivation, apoptotic cascades, and metabolic reprogramming, providing novel insights for PRRSV vaccine design and immunomodulatory strategies.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"313 ","pages":"Article 110868"},"PeriodicalIF":2.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145918577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Copper-based drugs inhibit infectious bronchitis virus (IBV) in vitro and in vivo 铜基药物体外和体内抑制传染性支气管炎病毒（IBV）

IF 2.7 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2026-02-01 Epub Date: 2025-12-29 DOI: 10.1016/j.vetmic.2025.110857

Lisen Lin , Jiaqi Li , Chao Shang , Dapeng Li , Mingzhe Sun , Gaojie Song , Guangbo Qu , Xiao Li , Ran Zhu , Cuiling Zhang , Qinghao He , Guibin Jiang

Infectious bronchitis (IB) is an acute respiratory disease caused by the infectious bronchitis virus (IBV), spreads rapidly and manifests with diverse clinical signs, posing a major significant to the poultry industry. Metal ions such as copper are known to possess notable antiviral properties. Therefore, we evaluated the potential efficacy of copper-based pharmaceuticals against IBV. Results demonstrated that the copper-based drugs significantly protected DF-1 cells from IBV-M41 infection, markedly increasing cell activity and reducing IBV N-gene level. Furthermore, these drugs enhanced antiviral immunity and exhibited anti-apoptotic activity in vitro. In addition, these drugs increased the survival rates of infected chicken embryos and chicks while reducing developmental disruptions, thereby demonstrating robust antiviral effects. Pathological examinations revealed that lesions in the lungs, trachea, kidneys, spleen and other organs of treated groups improved to varying degrees, with a down-regulation of IBV N-gene level in chicks. Our study showed that the copper-based drugs exhibited anti-IBV-M41 both in vitro and in vivo, which provides a theoretical and experimental basis for exploring the anti-coronaviral effects of metal-based drug candidates.

传染性支气管炎（IB）是由传染性支气管炎病毒（IBV）引起的一种急性呼吸道疾病，传播迅速，临床症状多样，对家禽业造成重大影响。众所周知，铜等金属离子具有显著的抗病毒特性。因此，我们评估了铜基药物对IBV的潜在疗效。结果表明，铜基药物能显著保护DF-1细胞免受IBV- m41感染，显著提高细胞活性，降低IBV n基因水平。此外，这些药物在体外增强抗病毒免疫并表现出抗凋亡活性。此外，这些药物增加了受感染鸡胚胎和雏鸡的存活率，同时减少了发育中断，从而显示出强大的抗病毒作用。病理检查显示，处理组雏鸡肺、气管、肾、脾等脏器病变均有不同程度改善，IBV n基因水平下调。我们的研究表明，铜基药物在体外和体内均表现出抗ibv - m41的活性，这为探索金属基候选药物的抗冠状病毒作用提供了理论和实验基础。

{"title":"Copper-based drugs inhibit infectious bronchitis virus (IBV) in vitro and in vivo","authors":"Lisen Lin , Jiaqi Li , Chao Shang , Dapeng Li , Mingzhe Sun , Gaojie Song , Guangbo Qu , Xiao Li , Ran Zhu , Cuiling Zhang , Qinghao He , Guibin Jiang","doi":"10.1016/j.vetmic.2025.110857","DOIUrl":"10.1016/j.vetmic.2025.110857","url":null,"abstract":"<div><div>Infectious bronchitis (IB) is an acute respiratory disease caused by the infectious bronchitis virus (IBV), spreads rapidly and manifests with diverse clinical signs, posing a major significant to the poultry industry. Metal ions such as copper are known to possess notable antiviral properties. Therefore, we evaluated the potential efficacy of copper-based pharmaceuticals against IBV. Results demonstrated that the copper-based drugs significantly protected DF-1 cells from IBV-M41 infection, markedly increasing cell activity and reducing IBV N-gene level. Furthermore, these drugs enhanced antiviral immunity and exhibited anti-apoptotic activity <em>in vitro</em>. In addition, these drugs increased the survival rates of infected chicken embryos and chicks while reducing developmental disruptions, thereby demonstrating robust antiviral effects. Pathological examinations revealed that lesions in the lungs, trachea, kidneys, spleen and other organs of treated groups improved to varying degrees, with a down-regulation of IBV N-gene level in chicks. Our study showed that the copper-based drugs exhibited anti-IBV-M41 both <em>in vitro</em> and <em>in vivo</em>, which provides a theoretical and experimental basis for exploring the anti-coronaviral effects of metal-based drug candidates.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"313 ","pages":"Article 110857"},"PeriodicalIF":2.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phosphorylation of T425 and methylation of R426 synergistically regulate IBDV VP1 function and viral replication T425磷酸化和R426甲基化协同调节IBDV VP1功能和病毒复制。

IF 2.7 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2026-02-01 Epub Date: 2026-01-05 DOI: 10.1016/j.vetmic.2026.110871

Huiping Liang , Xiangxiang Gao , Yan Xiao , Rongzhao Sun , Biao Chen , Qinghua Zeng , Zheng Chen , Xiangdong Wu , Huansheng Wu

Post-translational modifications (PTMs) are essential regulators of viral protein function and replication efficiency. Infectious bursal disease virus (IBDV) polymerase VP1 has been reported to undergo multiple PTMs; however, the interplay among different modifications remains poorly understood. In this study, we identified a novel phosphorylation site at threonine 425 (T425) adjacent to the previously characterized arginine 426 (R426) methylation site of VP1. Mass spectrometry and phospho-specific antibodies confirmed phosphorylation at T425 during IBDV replication. Functional assays demonstrated that phosphorylation at T425 enhances VP1 polymerase activity and promotes viral replication, whereas mutation of this site markedly impaired viral growth. Inhibition experiments further indicated that inhibitor IX significantly inhibit T425 phosphorylation. Importantly, we revealed a synergistic relationship between T425 phosphorylation and PRMT5-mediated R426 methylation, as loss of either modification attenuated the other. Recombinant IBDV harboring the T425A/R426A double mutation exhibited significantly reduced replication capacity compared to single mutants. Together, our findings uncover a previously unrecognized crosstalk between adjacent phosphorylation and methylation sites in VP1, providing new insights into the fine-tuned regulation of IBDV replication and offering potential targets for antiviral strategies and vaccine development.

翻译后修饰（PTMs）是病毒蛋白功能和复制效率的重要调节因子。据报道，传染性法氏囊病病毒（IBDV）聚合酶VP1可发生多次ptm；然而，不同修饰之间的相互作用仍然知之甚少。在这项研究中，我们在苏氨酸425 （T425）上发现了一个新的磷酸化位点，与先前表征的VP1的精氨酸426 （R426）甲基化位点相邻。质谱分析和磷酸化特异性抗体证实了IBDV复制过程中T425位点的磷酸化。功能分析表明，T425位点的磷酸化增强了VP1聚合酶的活性，促进了病毒的复制，而该位点的突变明显损害了病毒的生长。抑制实验进一步表明，抑制剂IX显著抑制T425磷酸化。重要的是，我们揭示了T425磷酸化和prmt5介导的R426甲基化之间的协同关系，因为失去任何一种修饰都会减弱另一种修饰。与单突变体相比，携带T425A/R426A双突变的重组IBDV的复制能力显著降低。总之，我们的研究结果揭示了VP1中相邻磷酸化和甲基化位点之间先前未被识别的串扰，为IBDV复制的微调调控提供了新的见解，并为抗病毒策略和疫苗开发提供了潜在的靶点。

{"title":"Phosphorylation of T425 and methylation of R426 synergistically regulate IBDV VP1 function and viral replication","authors":"Huiping Liang , Xiangxiang Gao , Yan Xiao , Rongzhao Sun , Biao Chen , Qinghua Zeng , Zheng Chen , Xiangdong Wu , Huansheng Wu","doi":"10.1016/j.vetmic.2026.110871","DOIUrl":"10.1016/j.vetmic.2026.110871","url":null,"abstract":"<div><div>Post-translational modifications (PTMs) are essential regulators of viral protein function and replication efficiency. Infectious bursal disease virus (IBDV) polymerase VP1 has been reported to undergo multiple PTMs; however, the interplay among different modifications remains poorly understood. In this study, we identified a novel phosphorylation site at threonine 425 (T425) adjacent to the previously characterized arginine 426 (R426) methylation site of VP1. Mass spectrometry and phospho-specific antibodies confirmed phosphorylation at T425 during IBDV replication. Functional assays demonstrated that phosphorylation at T425 enhances VP1 polymerase activity and promotes viral replication, whereas mutation of this site markedly impaired viral growth. Inhibition experiments further indicated that inhibitor IX significantly inhibit T425 phosphorylation. Importantly, we revealed a synergistic relationship between T425 phosphorylation and PRMT5-mediated R426 methylation, as loss of either modification attenuated the other. Recombinant IBDV harboring the T425A/R426A double mutation exhibited significantly reduced replication capacity compared to single mutants. Together, our findings uncover a previously unrecognized crosstalk between adjacent phosphorylation and methylation sites in VP1, providing new insights into the fine-tuned regulation of IBDV replication and offering potential targets for antiviral strategies and vaccine development.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"313 ","pages":"Article 110871"},"PeriodicalIF":2.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145935046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

PRRSV Nsp12 targets PSMA2 to suppress host proteasome activity and promote viral survival PRRSV Nsp12靶向PSMA2抑制宿主蛋白酶体活性，促进病毒存活。

IF 2.7 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2026-02-01 Epub Date: 2025-12-10 DOI: 10.1016/j.vetmic.2025.110835

Wei Li , Danjiao Yang , Ruiqing Wang , Lan Lan , Xinxin Qiu , Xinglong Wang

Porcine reproductive and respiratory syndrome virus (PRRSV) poses a significant threat to the global swine industry, employing complex mechanisms to interact with the host and evade host immune responses. The ubiquitin-proteasome system (UPS) is central to host antiviral innate immunity, yet its interplay with PRRSV remains poorly understood. In this study, Proteasome 20S Subunit Alpha 2 (PSMA2) was identified as a novel host restriction factor against highly pathogenic PRRSV (HP-PRRSV). Through overexpression and siRNA knockdown experiments, it was demonstrated that PSMA2 effectively inhibits PRRSV replication in a time- and dose-dependent manner, exerting antiviral effects during the mid-to-late post-entry stages of replication. Mechanistically, PSMA2 overexpression enhances overall cellular proteasome activity and specifically upregulates transcription of immunoproteasome activator subunits PSME1, PSME2, and PSME3. As a countermeasure, the PRRSV JXA1 strain induces the degradation of PSMA2 protein via the autophagy pathway, a process contingent on active viral replication. Further screening identified PRRSV nonstructural protein 12 (Nsp12) as a viral factor associated with the autophagy-dependent reduction of PSMA2. In parallel, PRRSV infection suppresses global proteasome activity, indicating that the virus adopts a two-pronged strategy to undermine this host defense pathway. These findings demonstrate that PRRSV hijacks autophagy machinery to eliminate a key proteasome-associated restriction factor. Collectively, our results highlight the intricate interplay between PRRSV and the host proteasome system and provide novel insights into viral pathogenesis.

猪繁殖与呼吸综合征病毒（PRRSV）通过复杂的机制与宿主相互作用，逃避宿主免疫应答，对全球养猪业构成重大威胁。泛素-蛋白酶体系统（UPS）是宿主抗病毒先天免疫的核心，但其与PRRSV的相互作用仍然知之甚少。本研究发现，蛋白酶体20S亚单位α 2 （PSMA2）是一种新的抗高致病性PRRSV （HP-PRRSV）宿主限制性因子。通过过表达和siRNA敲低实验，证实PSMA2以时间和剂量依赖的方式有效抑制PRRSV的复制，在进入复制后中后期发挥抗病毒作用。从机制上讲，PSMA2过表达增强了细胞蛋白酶体的整体活性，并特异性上调了免疫蛋白酶体激活子亚基PSME1、PSME2和PSME3的转录。作为对策，PRRSV JXA1菌株通过自噬途径诱导PSMA2蛋白的降解，这一过程取决于活跃的病毒复制。进一步筛选发现PRRSV非结构蛋白12 （Nsp12）是与自噬依赖性PSMA2减少相关的病毒因子。同时，PRRSV感染抑制全局蛋白酶体活性，表明该病毒采用双管齐下的策略来破坏这一宿主防御途径。这些发现表明PRRSV劫持自噬机制来消除一个关键的蛋白酶体相关限制因子。总的来说，我们的研究结果强调了PRRSV与宿主蛋白酶体系统之间复杂的相互作用，并为病毒的发病机制提供了新的见解。

{"title":"PRRSV Nsp12 targets PSMA2 to suppress host proteasome activity and promote viral survival","authors":"Wei Li , Danjiao Yang , Ruiqing Wang , Lan Lan , Xinxin Qiu , Xinglong Wang","doi":"10.1016/j.vetmic.2025.110835","DOIUrl":"10.1016/j.vetmic.2025.110835","url":null,"abstract":"<div><div>Porcine reproductive and respiratory syndrome virus (PRRSV) poses a significant threat to the global swine industry, employing complex mechanisms to interact with the host and evade host immune responses. The ubiquitin-proteasome system (UPS) is central to host antiviral innate immunity, yet its interplay with PRRSV remains poorly understood. In this study, Proteasome 20S Subunit Alpha 2 (PSMA2) was identified as a novel host restriction factor against highly pathogenic PRRSV (HP-PRRSV). Through overexpression and siRNA knockdown experiments, it was demonstrated that PSMA2 effectively inhibits PRRSV replication in a time- and dose-dependent manner, exerting antiviral effects during the mid-to-late post-entry stages of replication. Mechanistically, PSMA2 overexpression enhances overall cellular proteasome activity and specifically upregulates transcription of immunoproteasome activator subunits PSME1, PSME2, and PSME3. As a countermeasure, the PRRSV JXA1 strain induces the degradation of PSMA2 protein via the autophagy pathway, a process contingent on active viral replication. Further screening identified PRRSV nonstructural protein 12 (Nsp12) as a viral factor associated with the autophagy-dependent reduction of PSMA2. In parallel, PRRSV infection suppresses global proteasome activity, indicating that the virus adopts a two-pronged strategy to undermine this host defense pathway. These findings demonstrate that PRRSV hijacks autophagy machinery to eliminate a key proteasome-associated restriction factor. Collectively, our results highlight the intricate interplay between PRRSV and the host proteasome system and provide novel insights into viral pathogenesis.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"313 ","pages":"Article 110835"},"PeriodicalIF":2.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145879052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Identification of porcine-derived atypical intestinal pathogenic Escherichia coli reveals to a hidden threat of extraintestinal infection 猪源非典型肠道致病性大肠杆菌的鉴定揭示了肠外感染的潜在威胁

IF 2.7 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2026-02-01 Epub Date: 2025-12-30 DOI: 10.1016/j.vetmic.2025.110860

Zhonghao Chen , Simin Lv , Shiyu Zhang , Yong Yu , Jiale Ma , Huochun Yao , Xinming Pan

Post-weaning diarrhea in piglets is primarily caused by enterotoxigenic Escherichia coli (ETEC) and Shiga toxin-producing E. coli (STEC). However, the diversity and combinations of virulence factors among clinical porcine isolates remain incompletely characterized. Here, we systematically screened 296 E. coli isolates from diarrheic piglets and identified nine isolates (3.0 %) that lacked classical ETEC/STEC virulence factors but co-harbored F18 fimbriae and a hemolysin gene cluster. These F18⁺&hly⁺ strains exhibited strong intestinal adhesion and colonization in vitro and in vivo and were designated enteroadherent hemolytic E. coli (EAHEC). Notably, EAHEC strains belonging to phylogroup D also displayed extraintestinal pathogenicity in mouse models, indicating cross-niche potential. Based on this finding, we identified 17 hybrid pathogenic E. coli (HyPEC) isolates (5.7 %) by PCR screening. These hybrid strains were classified based on two criteria: (i) the presence of both intestinal virulence markers (ETEC/EPEC/STEC/EAHEC) and ExPEC/UPEC-associated virulence genes, or (ii) the carriage of ExPEC/UPEC-associated virulence genes despite lacking classical intestinal pathotype markers, while nonetheless exhibiting intestinal pathogenic phenotypes. Phenotypic assays showed that most HyPEC strains retained strong intestinal colonization capacity, whereas systemic infection capacity varied by phylogroup, with B2 and D lineages exhibiting the highest virulence. Overall, our study documents the existence and virulence potential of atypical enteroadherent hemolytic and hybrid E. coli in pigs, highlights diverse virulence-module combinations in porcine isolates, and indicates that recognition of such atypical/hybrid strains may have implications for future diagnostics and surveillance of porcine diarrheal disease.

仔猪断奶后腹泻主要由产肠毒素大肠杆菌（ETEC）和产志贺毒素大肠杆菌（STEC）引起。然而，临床猪分离株中毒力因子的多样性和组合仍然不完全确定。在这里，我们系统地筛选了296株来自腹泻仔猪的大肠杆菌，并鉴定出9株（3.0 %）缺乏经典的ETEC/STEC毒力因子，但同时携带F18菌膜和溶血素基因群。这些F18 + & hly +菌株在体外和体内均表现出较强的肠道粘附性和定植性，被命名为肠黏附溶血性大肠杆菌（EAHEC）。值得注意的是，属于D系的EAHEC菌株在小鼠模型中也表现出肠外致病性，这表明了跨生态位的潜力。基于这一发现，我们通过PCR筛选鉴定出17株杂交致病性大肠杆菌（HyPEC）（5.7% %）。这些杂交菌株根据两个标准进行分类：(i)肠道毒力标记（ETEC/EPEC/STEC/EAHEC）和ExPEC/ upec相关毒力基因的存在，或（ii）携带ExPEC/ upec相关毒力基因，尽管缺乏经典的肠道病理标记，但仍表现出肠道致病表型。表型分析表明，大多数HyPEC菌株具有较强的肠道定植能力，而系统感染能力因系群而异，B2和D系表现出最高的毒力。总的来说，我们的研究记录了猪中非典型肠黏附溶血性大肠杆菌和杂交大肠杆菌的存在和毒力潜力，强调了猪分离株中不同的毒力模块组合，并表明识别这种非典型/杂交菌株可能对未来猪腹泻病的诊断和监测具有重要意义。

{"title":"Identification of porcine-derived atypical intestinal pathogenic Escherichia coli reveals to a hidden threat of extraintestinal infection","authors":"Zhonghao Chen , Simin Lv , Shiyu Zhang , Yong Yu , Jiale Ma , Huochun Yao , Xinming Pan","doi":"10.1016/j.vetmic.2025.110860","DOIUrl":"10.1016/j.vetmic.2025.110860","url":null,"abstract":"<div><div>Post-weaning diarrhea in piglets is primarily caused by enterotoxigenic <em>Escherichia coli</em> (ETEC) and Shiga toxin-producing <em>E. coli</em> (STEC). However, the diversity and combinations of virulence factors among clinical porcine isolates remain incompletely characterized. Here, we systematically screened 296 <em>E. coli</em> isolates from diarrheic piglets and identified nine isolates (3.0 %) that lacked classical ETEC/STEC virulence factors but co-harbored F18 fimbriae and a hemolysin gene cluster. These F18⁺&hly⁺ strains exhibited strong intestinal adhesion and colonization <em>in vitro</em> and <em>in vivo</em> and were designated enteroadherent hemolytic <em>E. coli</em> (EAHEC). Notably, EAHEC strains belonging to phylogroup D also displayed extraintestinal pathogenicity in mouse models, indicating cross-niche potential. Based on this finding, we identified 17 hybrid pathogenic <em>E. coli</em> (HyPEC) isolates (5.7 %) by PCR screening. These hybrid strains were classified based on two criteria: (i) the presence of both intestinal virulence markers (ETEC/EPEC/STEC/EAHEC) and ExPEC/UPEC-associated virulence genes, or (ii) the carriage of ExPEC/UPEC-associated virulence genes despite lacking classical intestinal pathotype markers, while nonetheless exhibiting intestinal pathogenic phenotypes. Phenotypic assays showed that most HyPEC strains retained strong intestinal colonization capacity, whereas systemic infection capacity varied by phylogroup, with B2 and D lineages exhibiting the highest virulence. Overall, our study documents the existence and virulence potential of atypical enteroadherent hemolytic and hybrid <em>E. coli</em> in pigs, highlights diverse virulence-module combinations in porcine isolates, and indicates that recognition of such atypical/hybrid strains may have implications for future diagnostics and surveillance of porcine diarrheal disease.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"313 ","pages":"Article 110860"},"PeriodicalIF":2.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

ANXA2 stabilizes mTOR at the plasma membrane to facilitate autophagic flux for CSFV release ANXA2稳定质膜上的mTOR，促进CSFV释放的自噬通量

IF 2.7 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2026-02-01 Epub Date: 2025-12-31 DOI: 10.1016/j.vetmic.2025.110863

Tao Wang , Liangcai Da , Junfang Zhao , Hong Yuan , Ying Sun , Liang Zhang , Kun Li , Jing Zhang , Pu Sun , Zhixun Zhao , Qiang Zhang , Yuanji Zhang , Yebing Liu , Xingwen Bai , Zengjun Lu

Classical swine fever virus (CSFV), a member of the Flaviviridae family, remains a major pathogen responsible for substantial economic losses in the global swine industry. Autophagy plays a critical role in the life cycle and virulence of CSFV, however, the mechanisms through which the virus regulates autophagy are still not fully understood. In this study, we identified ANXA2, a calcium-dependent phospholipid-binding protein, within autophagy-derived vesicles that facilitate CSFV transmission. We demonstrated that ANXA2 modulates CSFV release in a manner dependent on autophagy. Moreover, multiple lines of evidence, including Western blot, LC3 puncta formation, tandem fluorescence assay, and electron microscopy, consistently showed that ANXA2 promotes CSFV-induced autophagy. Mechanistically, ANXA2 overexpression reduced mTOR phosphorylation, while its knockout increased phosphorylation. Comprehensive binding assays revealed that both ANXA2 and the CSFV envelope protein E2 interact with mTOR with high affinity. Domain mapping further indicated that ANXA2 and E2 bind to distinct regions of mTOR, suggesting a synergistic mechanism for autophagy activation. Confocal microscopy showed that ANXA2 facilitates mTOR accumulation at the plasma membrane during infection. Importantly, relocalizing ANXA2 to mitochondria attenuated CSFV-induced autophagy. Collectively, these results indicate that ANXA2 modulates CSFV-triggered autophagy by controlling mTOR subcellular localization, thereby influencing viral production. This study unveils a novel strategy by which CSFV co-opts the ANXA2–mTOR axis to manipulate autophagic processes, highlighting potential targets for future antiviral interventions.

经典猪瘟病毒（CSFV）是黄病毒科的一员，仍然是造成全球养猪业重大经济损失的主要病原体。自噬在猪瘟病毒的生命周期和毒力中起着至关重要的作用，然而，病毒调控自噬的机制尚不完全清楚。在这项研究中，我们在自噬衍生的囊泡中发现了ANXA2，一种钙依赖性磷脂结合蛋白，可促进猪瘟病毒的传播。我们证明了ANXA2以依赖于自噬的方式调节猪瘟病毒的释放。此外，包括Western blot、LC3斑点形成、串联荧光实验和电镜在内的多种证据一致表明，ANXA2促进了csfv诱导的自噬。机制上，ANXA2过表达降低了mTOR的磷酸化，而敲除则增加了磷酸化。综合结合实验显示，ANXA2和CSFV包膜蛋白E2都与mTOR有高亲和力的相互作用。结构域定位进一步表明，ANXA2和E2结合到mTOR的不同区域，提示自噬激活的协同机制。共聚焦显微镜显示，在感染过程中，ANXA2促进了mTOR在质膜上的积累。重要的是，将ANXA2重新定位到线粒体可以减弱猪瘟病毒诱导的自噬。综上所述，这些结果表明ANXA2通过控制mTOR亚细胞定位来调节猪瘟引发的自噬，从而影响病毒的产生。这项研究揭示了CSFV利用ANXA2-mTOR轴操纵自噬过程的一种新策略，突出了未来抗病毒干预的潜在靶点。

{"title":"ANXA2 stabilizes mTOR at the plasma membrane to facilitate autophagic flux for CSFV release","authors":"Tao Wang , Liangcai Da , Junfang Zhao , Hong Yuan , Ying Sun , Liang Zhang , Kun Li , Jing Zhang , Pu Sun , Zhixun Zhao , Qiang Zhang , Yuanji Zhang , Yebing Liu , Xingwen Bai , Zengjun Lu","doi":"10.1016/j.vetmic.2025.110863","DOIUrl":"10.1016/j.vetmic.2025.110863","url":null,"abstract":"<div><div>Classical swine fever virus (CSFV), a member of the <em>Flaviviridae</em> family, remains a major pathogen responsible for substantial economic losses in the global swine industry. Autophagy plays a critical role in the life cycle and virulence of CSFV, however, the mechanisms through which the virus regulates autophagy are still not fully understood. In this study, we identified ANXA2, a calcium-dependent phospholipid-binding protein, within autophagy-derived vesicles that facilitate CSFV transmission. We demonstrated that ANXA2 modulates CSFV release in a manner dependent on autophagy. Moreover, multiple lines of evidence, including Western blot, LC3 puncta formation, tandem fluorescence assay, and electron microscopy, consistently showed that ANXA2 promotes CSFV-induced autophagy. Mechanistically, ANXA2 overexpression reduced mTOR phosphorylation, while its knockout increased phosphorylation. Comprehensive binding assays revealed that both ANXA2 and the CSFV envelope protein E2 interact with mTOR with high affinity. Domain mapping further indicated that ANXA2 and E2 bind to distinct regions of mTOR, suggesting a synergistic mechanism for autophagy activation. Confocal microscopy showed that ANXA2 facilitates mTOR accumulation at the plasma membrane during infection. Importantly, relocalizing ANXA2 to mitochondria attenuated CSFV-induced autophagy. Collectively, these results indicate that ANXA2 modulates CSFV-triggered autophagy by controlling mTOR subcellular localization, thereby influencing viral production. This study unveils a novel strategy by which CSFV co-opts the ANXA2–mTOR axis to manipulate autophagic processes, highlighting potential targets for future antiviral interventions.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"313 ","pages":"Article 110863"},"PeriodicalIF":2.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

ENTR1 stabilizes MAVS by inhibiting NIX-mediated mitophagy to restrict BPIV3 and VSV replication ENTR1通过抑制nix介导的线粒体自噬来抑制BPIV3和VSV的复制，从而稳定MAVS。

IF 2.7 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2026-02-01 Epub Date: 2025-12-31 DOI: 10.1016/j.vetmic.2025.110865

Xiaoyang Yao , Xingyu Li , Lixiang Shi, Hongmei Wang, Hongbin He

Endosome-associated trafficking regulator 1 (ENTR1) is implicated in cell apoptosis, cytokinesis, and adipogenesis, but its role in antiviral innate immunity has not been elucidated. In this study, we identify ENTR1 as a positive regulatory factor for type I interferon (IFN-I) signaling pathway, which suppresses bovine parainfluenza virus type 3 (BPIV3) and vesicular stomatitis virus (VSV) replication. Further investigations revealed that ENTR1 deficiency enhanced Nip3-like protein X (NIX)-mediated mitophagy, leading to accelerated degradation of mitochondrial antiviral signaling protein (MAVS) during viral infection. Mechanistically, ENTR1 knockout resulted in increased accumulation of NIX on mitochondria, which promoted the autophagic degradation of MAVS. Importantly, silencing NIX rescued MAVS protein levels and significantly reduced viral titers in ENTR1-deficient cells. Moreover, NIX silencing prevented the degradation of MAVS and consequently reduced viral titers in ENTR1-deficient cells. Consequently, our findings reveal a novel regulatory axis in which ENTR1 stabilizes MAVS by suppressing NIX-dependent mitophagy, thereby enhancing antiviral IFN-I responses. This study not only uncovers a previously unrecognized function of ENTR1 in antiviral immunity but also identifies ENTR1 as a potential target for developing broad-spectrum antiviral therapeutics against RNA viruses.

内核体相关运输调节因子1 （ENTR1）与细胞凋亡、细胞分裂和脂肪形成有关，但其在抗病毒先天免疫中的作用尚未阐明。在这项研究中，我们发现ENTR1是I型干扰素（IFN-I）信号通路的正调控因子，该信号通路抑制牛副流感病毒3型（BPIV3）和水疱性口炎病毒（VSV）的复制。进一步的研究表明，ENTR1缺陷增强了nip3样蛋白X （NIX）介导的线粒体自噬，导致病毒感染期间线粒体抗病毒信号蛋白（MAVS）的降解加速。机制上，ENTR1敲除导致线粒体上NIX的积累增加，从而促进MAVS的自噬降解。重要的是，沉默NIX可挽救MAVS蛋白水平，并显著降低entr1缺陷细胞中的病毒滴度。此外，NIX沉默阻止了MAVS的降解，从而降低了entr1缺陷细胞中的病毒滴度。因此，我们的研究结果揭示了一个新的调控轴，其中ENTR1通过抑制nix依赖性的有丝分裂来稳定MAVS，从而增强抗病毒IFN-I反应。这项研究不仅揭示了ENTR1在抗病毒免疫中的一个以前未被认识到的功能，而且还确定了ENTR1作为开发针对RNA病毒的广谱抗病毒治疗的潜在靶点。

{"title":"ENTR1 stabilizes MAVS by inhibiting NIX-mediated mitophagy to restrict BPIV3 and VSV replication","authors":"Xiaoyang Yao , Xingyu Li , Lixiang Shi, Hongmei Wang, Hongbin He","doi":"10.1016/j.vetmic.2025.110865","DOIUrl":"10.1016/j.vetmic.2025.110865","url":null,"abstract":"<div><div>Endosome-associated trafficking regulator 1 (ENTR1) is implicated in cell apoptosis, cytokinesis, and adipogenesis, but its role in antiviral innate immunity has not been elucidated. In this study, we identify ENTR1 as a positive regulatory factor for type I interferon (IFN-I) signaling pathway, which suppresses bovine parainfluenza virus type 3 (BPIV3) and vesicular stomatitis virus (VSV) replication. Further investigations revealed that ENTR1 deficiency enhanced Nip3-like protein X (NIX)-mediated mitophagy, leading to accelerated degradation of mitochondrial antiviral signaling protein (MAVS) during viral infection. Mechanistically, ENTR1 knockout resulted in increased accumulation of NIX on mitochondria, which promoted the autophagic degradation of MAVS. Importantly, silencing NIX rescued MAVS protein levels and significantly reduced viral titers in ENTR1-deficient cells. Moreover, NIX silencing prevented the degradation of MAVS and consequently reduced viral titers in ENTR1-deficient cells. Consequently, our findings reveal a novel regulatory axis in which ENTR1 stabilizes MAVS by suppressing NIX-dependent mitophagy, thereby enhancing antiviral IFN-I responses. This study not only uncovers a previously unrecognized function of ENTR1 in antiviral immunity but also identifies ENTR1 as a potential target for developing broad-spectrum antiviral therapeutics against RNA viruses.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"313 ","pages":"Article 110865"},"PeriodicalIF":2.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145913173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluation of residual virulence and protective efficacy for Brucella melitensis vaccine strain M5-90 in mice and guinea pigs M5-90布氏菌疫苗在小鼠和豚鼠体内的残留毒力和保护效果评价。

IF 2.7 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2026-02-01 Epub Date: 2026-01-02 DOI: 10.1016/j.vetmic.2026.110870

Chenchen Lu , Chenglan Zhang , Yanan Li , Zujian Qiao , Xijun Wang , Weiye Chen , Xiaoyi Chen , Qian Jiang , Da Xu , Zhigao Bu , Sen Hu

Brucellosis, a globally significant zoonosis caused by Brucella species, leads to severe reproductive complications including abortion and infertility in animals and humans. Vaccination remains a cornerstone strategy for the control of brucellosis transmission. The Brucella melitensis vaccine strain M5‑90 was developed in China during the 1970s–1980s by attenuation from virulent M28 strain. This study systematically evaluated the safety and protective efficacy of M5‑90 in mouse and guinea pigs models. Results indicated that M5‑90 was completely cleared from mice within 15 weeks after subcutaneous inoculation of 10⁸ CFU, exhibiting a 50 % recovery time (RT50) of 9.27 ± 1.26 weeks. Bacterial replication was not dose-dependent. The bacterial burden in M5‑90-infected mice reduced by 1–3 log10 compared with the virulent M28 group at a challenge dose of 10⁶ CFU (P < 0.05). Immunization with 10⁵ CFU conferred significant protection against virulent B. melitensis M28 and B. abortus 544 challenges at 45 and 150 days post-vaccination, respectively (P < 0.05 or P < 0.01). In guinea pigs, the splenic bacterial load of M5‑90 was markedly lower than that in the M28 group (2440 ± 240 vs. 223,000 ± 3800 CFU/g; P < 0.001). A dose of 3 × 10⁸ CFU of M5‑90 provided complete (100 %) and strong (90 %) protection against M28 and 544 challenges, respectively. In summary, Brucella melitensis vaccine strain M5‑90 demonstrates favorable safety and protective efficacy in mice and guinea pigs, supporting its potential as a promising vaccine for brucellosis control.

布鲁氏菌病是由布鲁氏菌引起的一种全球重要的人畜共患病，可导致严重的生殖并发症，包括动物和人类的流产和不孕。疫苗接种仍然是控制布鲁氏菌病传播的基石战略。在20世纪70年代至80年代，中国通过对毒力强的M28菌株进行减毒，研制出了梅利氏布鲁氏菌疫苗株M5‑90。本研究在小鼠和豚鼠模型中系统评价了M5‑90的安全性和保护作用。结果表明，皮下接种10⁸CFU后15周内，小鼠体内的M5‑90被完全清除，恢复时间（RT50）为9.27 ± 1.26周，为50% %。细菌复制不依赖于剂量。在10⁶CFU的攻毒剂量下，M5‑90感染小鼠的细菌负荷比M28毒力组减少了1-3 log10

{"title":"Evaluation of residual virulence and protective efficacy for Brucella melitensis vaccine strain M5-90 in mice and guinea pigs","authors":"Chenchen Lu , Chenglan Zhang , Yanan Li , Zujian Qiao , Xijun Wang , Weiye Chen , Xiaoyi Chen , Qian Jiang , Da Xu , Zhigao Bu , Sen Hu","doi":"10.1016/j.vetmic.2026.110870","DOIUrl":"10.1016/j.vetmic.2026.110870","url":null,"abstract":"<div><div>Brucellosis, a globally significant zoonosis caused by <em>Brucella</em> species, leads to severe reproductive complications including abortion and infertility in animals and humans. Vaccination remains a cornerstone strategy for the control of brucellosis transmission. The <em>Brucella melitensis</em> vaccine strain M5‑90 was developed in China during the 1970s–1980s by attenuation from virulent M28 strain. This study systematically evaluated the safety and protective efficacy of M5‑90 in mouse and guinea pigs models. Results indicated that M5‑90 was completely cleared from mice within 15 weeks after subcutaneous inoculation of 10⁸ CFU, exhibiting a 50 % recovery time (RT50) of 9.27 ± 1.26 weeks. Bacterial replication was not dose-dependent. The bacterial burden in M5‑90-infected mice reduced by 1–3 log10 compared with the virulent M28 group at a challenge dose of 10⁶ CFU (<em>P</em> < 0.05). Immunization with 10⁵ CFU conferred significant protection against virulent <em>B. melitensis</em> M28 and <em>B. abortus</em> 544 challenges at 45 and 150 days post-vaccination, respectively (<em>P</em> < 0.05 or <em>P</em> < 0.01). In guinea pigs, the splenic bacterial load of M5‑90 was markedly lower than that in the M28 group (2440 ± 240 vs. 223,000 ± 3800 CFU/g; <em>P</em> < 0.001). A dose of 3 × 10⁸ CFU of M5‑90 provided complete (100 %) and strong (90 %) protection against M28 and 544 challenges, respectively. In summary, <em>Brucella melitensis</em> vaccine strain M5‑90 demonstrates favorable safety and protective efficacy in mice and guinea pigs, supporting its potential as a promising vaccine for brucellosis control.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"313 ","pages":"Article 110870"},"PeriodicalIF":2.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145918515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Functional characterisation of metabolism-related genes required for the survival of Mycoplasma bovis in association with host cells 与宿主细胞相关的牛支原体存活所需的代谢相关基因的功能特征

IF 2.7 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2026-02-01 Epub Date: 2025-12-30 DOI: 10.1016/j.vetmic.2025.110861

Shijie Geng , Sheik Nadeem Elahee Doomun , Jordi Hondrogiannis , David P. De Souza , Anna Kanci Condello , Glenn F. Browning , Sara M. Klose , Kelly A. Tivendale , Nadeeka K. Wawegama

Metabolic functions of mycoplasmas play an important role in their interactions with their host. Recent studies examining the capacity of mutants of Mycoplasma bovis to survive in co-culture with Madin-Darby bovine kidney (MDBK) cells have identified three genes, MBOVPG45_0728, MBOVPG45_0028 and MBOVPG45_0327, that are essential for the survival of M. bovis in association with host cells. In the study described here, the metabolic profiles of the mutant strains with transposons inserted into these genes (∆MBOVPG45_0728, ∆MBOVPG45_0028 and ∆MBOVPG45_0327) were compared with that of the parent strain, PG45, to investigate the metabolic functions of the proteins. Steady-state metabolomic analysis did not identify significant alterations in metabolites associated with glucose metabolism in the ∆MBOVPG45_0728 mutant, suggesting that the product of MBOVPG45_0728 does not have the role in phosphoglucomutase activity predicted by bioinformatic analysis, and may play a role in amino acid and lipid metabolism. Metabolomic footprinting analyses detected significant differences in changes in medium components in cultures of ∆MBOVPG45_0028 and ∆MBOVPG45_0327 compared to PG45. These results were consistent with bioinformatic predictions that these two genes encoded components of transporter systems, and suggested that the protein encoded by the MBOVPG45_0028 gene is involved in nucleoside uptake, and that encoded by the MBOVPG45_0327 gene is involved in the efflux of organic acids. Overall, comparative metabolomic profiling revealed metabolic functions of M. bovis that are critical in interactions with host cells, furthering our understanding of metabolic mechanisms required for successful infection with M. bovis.

支原体的代谢功能在其与宿主的相互作用中起着重要作用。最近的研究检测了牛支原体突变体与Madin-Darby牛肾（MDBK）细胞共培养的存活能力，发现了MBOVPG45_0728、MBOVPG45_0028和MBOVPG45_0327三个基因，它们对牛支原体与宿主细胞联合存活至关重要。在本研究中，将转座子插入这些基因的突变菌株（∆MBOVPG45_0728，∆MBOVPG45_0028和∆MBOVPG45_0327）与亲本菌株PG45的代谢谱进行比较，以研究这些蛋白质的代谢功能。稳态代谢组学分析未发现∆MBOVPG45_0728突变体中与葡萄糖代谢相关的代谢物发生显著变化，这表明MBOVPG45_0728的产物不具有生物信息学分析预测的磷酸化葡萄糖糖化酶活性的作用，而可能在氨基酸和脂质代谢中发挥作用。代谢组学足迹分析发现，与PG45相比，∆MBOVPG45_0028和∆MBOVPG45_0327培养物中培养基成分的变化存在显著差异。这些结果与生物信息学预测一致，即这两个基因编码转运系统组分，并提示MBOVPG45_0028基因编码的蛋白质参与核苷摄取，MBOVPG45_0327基因编码的蛋白质参与有机酸的外排。总的来说，比较代谢组学分析揭示了牛分枝杆菌的代谢功能，这在与宿主细胞的相互作用中是至关重要的，进一步加深了我们对牛分枝杆菌成功感染所需的代谢机制的理解。

{"title":"Functional characterisation of metabolism-related genes required for the survival of Mycoplasma bovis in association with host cells","authors":"Shijie Geng , Sheik Nadeem Elahee Doomun , Jordi Hondrogiannis , David P. De Souza , Anna Kanci Condello , Glenn F. Browning , Sara M. Klose , Kelly A. Tivendale , Nadeeka K. Wawegama","doi":"10.1016/j.vetmic.2025.110861","DOIUrl":"10.1016/j.vetmic.2025.110861","url":null,"abstract":"<div><div>Metabolic functions of mycoplasmas play an important role in their interactions with their host. Recent studies examining the capacity of mutants of <em>Mycoplasma bovis</em> to survive in co-culture with Madin-Darby bovine kidney (MDBK) cells have identified three genes, MBOVPG45_0728, MBOVPG45_0028 and MBOVPG45_0327, that are essential for the survival of <em>M. bovis</em> in association with host cells. In the study described here, the metabolic profiles of the mutant strains with transposons inserted into these genes (∆MBOVPG45_0728, ∆MBOVPG45_0028 and ∆MBOVPG45_0327) were compared with that of the parent strain, PG45, to investigate the metabolic functions of the proteins. Steady-state metabolomic analysis did not identify significant alterations in metabolites associated with glucose metabolism in the ∆MBOVPG45_0728 mutant, suggesting that the product of MBOVPG45_0728 does not have the role in phosphoglucomutase activity predicted by bioinformatic analysis, and may play a role in amino acid and lipid metabolism. Metabolomic footprinting analyses detected significant differences in changes in medium components in cultures of ∆MBOVPG45_0028 and ∆MBOVPG45_0327 compared to PG45. These results were consistent with bioinformatic predictions that these two genes encoded components of transporter systems, and suggested that the protein encoded by the MBOVPG45_0028 gene is involved in nucleoside uptake, and that encoded by the MBOVPG45_0327 gene is involved in the efflux of organic acids. Overall, comparative metabolomic profiling revealed metabolic functions of <em>M. bovis</em> that are critical in interactions with host cells, furthering our understanding of metabolic mechanisms required for successful infection with <em>M. bovis</em>.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"313 ","pages":"Article 110861"},"PeriodicalIF":2.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanistic study of PEDV NSP3-mediated regulation of host innate immune responses via ubiquitin removal and UPR pathway modulation PEDV nsp3通过泛素去除和UPR通路调控宿主先天免疫应答的机制研究

IF 2.7 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2026-02-01 Epub Date: 2026-01-06 DOI: 10.1016/j.vetmic.2026.110875

Cheng Xin , Xiaolu Zhang , Tao Zhou , Jingming Zhou , Xifang Zhu , Hongliang Liu , Aiping Wang

The endoplasmic reticulum (ER) maintains protein-folding homeostasis and initiates antiviral responses via the unfolded protein response (UPR). Porcine epidemic diarrhea virus (PEDV) has evolved to exploit this process through its nonstructural protein 3 (NSP3). Here, we identify NSP3 as a multifunctional deubiquitinase that remodels ER stress signaling and redox homeostasis to facilitate viral replication and immune evasion. NSP3 suppresses GRP78 expression while selectively activating PERK–eIF2α–ATF4 and IRE1α–XBP1s pathways but inhibits ATF6 nuclear translocation. Mechanistically, NSP3’s PLP2 domain removes K48- and K63-linked ubiquitin chains from KEAP1, IRE1α, and ATF6, thereby fine-tuning their activity. Deubiquitination of KEAP1 promotes KEAP1–CUL3 complex stability and enhances NRF2 degradation, disrupting the antioxidant axis (NRF2–NQO1–HMOX1) while activating the ATF4–ERO1A–NOX4 pathway to elevate reactive oxygen species (ROS) levels without cytotoxicity. Functionally, activation of the PERK–NRF2 axis suppresses PEDV replication, whereas inhibition of either component enhances viral growth, highlighting a cooperative antiviral role. In contrast, activation of the IRE1α–XBP1s branch promotes replication but can be antagonized by NRF2 activation, indicating crosstalk between these pathways. Although ATF6 alone has minimal impact, its modulation by NRF2 shapes viral replication outcomes. Collectively, our findings reveal that PEDV NSP3 orchestrates differential deubiquitination of ER stress sensors to manipulate UPR–ROS signaling and redox balance, thereby subverting host defenses and promoting viral survival, providing mechanistic insight into coronavirus–host interactions and potential antiviral targets.

内质网（ER）维持蛋白折叠稳态，并通过未折叠蛋白反应（UPR）启动抗病毒反应。猪流行性腹泻病毒（PEDV）已经进化到通过其非结构蛋白3 （NSP3）利用这一过程。在这里，我们确定NSP3是一种多功能去泛素酶，它重塑内质网应激信号和氧化还原稳态，以促进病毒复制和免疫逃避。NSP3抑制GRP78表达，选择性激活PERK-eIF2α-ATF4和IRE1α-XBP1s通路，抑制ATF6核易位。机制上，NSP3的PLP2结构域从KEAP1、IRE1α和ATF6中去除K48-和k63 -连接的泛素链，从而微调它们的活性。KEAP1的去泛素化促进了KEAP1 - cul3复合物的稳定性，增强了NRF2的降解，破坏了抗氧化轴（NRF2 - nqo1 - hmox1），同时激活了ATF4-ERO1A-NOX4通路，在不产生细胞毒性的情况下提高了活性氧（ROS）水平。功能上，PERK-NRF2轴的激活抑制PEDV复制，而抑制任一组分均可增强病毒生长，突出了协同抗病毒作用。相比之下，IRE1α-XBP1s分支的激活促进了复制，但可以被NRF2激活拮抗，表明这些途径之间存在串扰。尽管ATF6单独影响很小，但NRF2对其的调节决定了病毒复制的结果。总之，我们的研究结果表明，PEDV NSP3协调内质网应激传感器的差异去泛素化，以操纵UPR-ROS信号传导和氧化还原平衡，从而破坏宿主防御并促进病毒存活，为冠状病毒与宿主相互作用和潜在抗病毒靶点提供了机制见解。

{"title":"Mechanistic study of PEDV NSP3-mediated regulation of host innate immune responses via ubiquitin removal and UPR pathway modulation","authors":"Cheng Xin , Xiaolu Zhang , Tao Zhou , Jingming Zhou , Xifang Zhu , Hongliang Liu , Aiping Wang","doi":"10.1016/j.vetmic.2026.110875","DOIUrl":"10.1016/j.vetmic.2026.110875","url":null,"abstract":"<div><div>The endoplasmic reticulum (ER) maintains protein-folding homeostasis and initiates antiviral responses via the unfolded protein response (UPR). Porcine epidemic diarrhea virus (PEDV) has evolved to exploit this process through its nonstructural protein 3 (NSP3). Here, we identify NSP3 as a multifunctional deubiquitinase that remodels ER stress signaling and redox homeostasis to facilitate viral replication and immune evasion. NSP3 suppresses GRP78 expression while selectively activating PERK–eIF2α–ATF4 and IRE1α–XBP1s pathways but inhibits ATF6 nuclear translocation. Mechanistically, NSP3’s PLP2 domain removes K48- and K63-linked ubiquitin chains from KEAP1, IRE1α, and ATF6, thereby fine-tuning their activity. Deubiquitination of KEAP1 promotes KEAP1–CUL3 complex stability and enhances NRF2 degradation, disrupting the antioxidant axis (NRF2–NQO1–HMOX1) while activating the ATF4–ERO1A–NOX4 pathway to elevate reactive oxygen species (ROS) levels without cytotoxicity. Functionally, activation of the PERK–NRF2 axis suppresses PEDV replication, whereas inhibition of either component enhances viral growth, highlighting a cooperative antiviral role. In contrast, activation of the IRE1α–XBP1s branch promotes replication but can be antagonized by NRF2 activation, indicating crosstalk between these pathways. Although ATF6 alone has minimal impact, its modulation by NRF2 shapes viral replication outcomes. Collectively, our findings reveal that PEDV NSP3 orchestrates differential deubiquitination of ER stress sensors to manipulate UPR–ROS signaling and redox balance, thereby subverting host defenses and promoting viral survival, providing mechanistic insight into coronavirus–host interactions and potential antiviral targets.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"313 ","pages":"Article 110875"},"PeriodicalIF":2.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0