Many poxviruses are significant zoonotic pathogens threatening public health. Autophagy, a regulated process vital for cellular homeostasis, can participate in defense against virus invasion. However, the relationship between poxviruses and host cell autophagy is not fully understood. This study shows that vaccinia virus (VACV) induces autophagy but blocks autophagosome-lysosome fusion. Modified vaccinia virus Ankara (MVA), an attenuated VACV strain that cannot replicate in most mammalian cells, fails to do so. Both pharmacological inhibition of early autophagy via 3-MA treatment and genetic ablation of ATG3 and ATG7 led to a significant enhancement of MVA replication. The VACV protein A52 inhibits autolysosome formation by disrupting interactions between SNAP29, STX17, and VAMP8, which is crucial for autophagic flux. Importantly, A52 also promotes the degradation of SNAP29, thereby aiding viral replication. Furthermore, SNAP29 is a newly identified host restriction factor for MVA, as its suppression enables MVA replication in human cells. These findings elucidate how poxviruses modulate autophagy for their own replication and further explain MVA's restriction in human cells.

Poxviruses are large DNA viruses with an arsenal of immune-modulatory genes, many of which remain uncharacterized. Proteins with ankyrin repeats are distinct features of poxviruses, although the biological functions of ankyrin proteins are not fully understood. Lumpy skin disease virus (LSDV) encodes five proteins with ankyrin repeats. Here, we reveal the role of LSDV012, an ankyrin protein, in conferring resistance to type I interferon (IFN) in cells. Deletion of LSDV012 from LSDV significantly impacted viral replication in the presence of type I IFN, highlighting the importance of LSDV012 in antagonizing type I IFN responses. Further investigation revealed that LSDV012 interacted with interferon-induced proteins with tetratricopeptide repeats (IFITs), particularly IFIT1, altering its subcellular localization, interacting with its C-terminus and inhibiting its RNA-binding ability without inducing its degradation. Phylogenetic analysis demonstrated that LSDV012 orthologs are conserved in capripoxviruses and cervidpoxviruses, and exhibit host species-specific interactions with IFIT1. Notably, LSDV012 was able to rescue the degradation of IFIT1 mediated by VACV C9. These findings provide novel insights into the viral strategies employed by LSDV to subvert host antiviral defenses and underscore the evolutionary adaptations of poxvirus ankyrin proteins in host species-specific immune evasion.

Liquid-liquid phase separation (LLPS) is a fundamental mechanism for the formation of membrane-less organelles, enabling cells to compartmentalize biochemical processes without membrane boundaries. In viral infections, LLPS is increasingly recognized as a strategy for organizing replication and transcriptional machinery. Here, we report that H5, a DNA-binding protein of vaccinia virus (VACV) could undergo LLPS through its N-terminal intrinsically disordered region (IDR). H5 forms dynamic and reversible condensates in both transfected and vacv infected cells, a property also observed with H5 orthologs from mpox virus and lumpy skin disease virus. Fluorescence recovery after photobleaching (FRAP) assays confirmed the liquid-like behavior of H5 condensates. Using structure-guided mutagenesis and phosphoproteomics, we identified two critical phosphorylation sites within the IDR, S127 and S130, which are essential for the interaction between H5 and DNA. These modifications are mediated redundantly by host proteins and viral B1 kinases. Mutations at these residues inhibit the binding of H5 to DNA, thereby directly or indirectly abolish LLPS formation, and impair viral replication factory assembly, leading to a marked reduction in viral DNA replication and progeny production, without affecting the synthesis of H5 or its subcellular localization. Our findings indicate that these two serine residues of H5 contribute to its interaction with DNA and the formation of LLPS, a process that may help organize viral replication compartments and facilitate interactions with key components of the DNA polymerase complex. This study uncovers a previously uncharacterized mechanism by which the poxvirus H5 protein promotes viral factory assembly and coordinates replication, and identifies a conserved regulatory axis that may serve as a potential therapeutic target across poxvirus species.

Toxoplasma gondii is a widely spread opportunistic pathogen that can infect nearly all warm-blooded vertebrates and cause serious toxoplasmosis in immunosuppressed animals and patients. However, the relationship between the host’s innate immune system and effector proteins is poorly understood, particularly with regard to how effectors antagonize cGAS-STING signaling during T. gondii infection. In this study, the ROP5 from the PRU strain of T. gondii was found to promote cGAS-STING-mediated immune responses. Mechanistically, ROP5 interacted with STING through predicted domain 2 and modulated cGAS-STING signaling in a predicted domain 3-dependent manner. Additionally, ROP5 strengthened cGAS-STING signaling by enhancing the K63-linked ubiquitination of STING. Consistently, ROP5 deficient PRU (PRUΔROP5) induced fewer type I IFN-related immune responses and replicated faster than the parental strain in RAW264.7 cells. Taken together, this study provides new insights into the mechanism by which ROP5 regulates T. gondii infection and provides new clues for strategies to prevent and control toxoplasmosis.

SUMMARY Many members of the poxvirus family are important zoonotic pathogens that pose a significant threat to human and animal health worldwide. Autophagy is a multi-step degradation pathway within cells, and one of its primary biological functions includes the clearance of invading viruses. Nevertheless, the interplay between poxviruses and host cell autophagy has not been fully elucidated. Here, we demonstrate that vaccinia virus (VACV) and lumpy skin disease virus (LSDV) induce incomplete autophagy and inhibit the fusion of autophagosomes and lysosomes, while modified vaccinia virus Ankara (MVA), an attenuated strain of VACV unable to replicate in almost all human cells, does not. Additionally, we screened and identified the VACV protein A52 as a key factor that obstruct the formation of autolysosomes. Mechanistically, A52 interacts with SNAP29 and inhibits its interaction with STX17 and VAMP8, both of which are binding partners of SNAP29 and are essential for complete autophagy. Moreover, A52 promotes the proteasomal degradation of SNAP29, which facilitates viral replication. We further revealed that SNAP29 functions as a restriction factor for MVA, as the suppression of SNAP29 allowed the replication of MVA in human cells. In summary, our data present a molecular mechanism by which poxviruses manipulate the cellular autophagic machinery and provide additional explanation for the restriction of MVA in human cells.

Goatpoxvirus (GTPV), sheeppoxvius (SPPV), and the Lumpy skin disease virus (LSDV) is a Capripoxvirus belonging to the family poxviridae. They can cause significant economic losses in countries where this disease are endemic. However, effective and convenient diagnostic tools against sera antibody are not readily available until now. Toward this goal, a polyclonal antibody competitive enzyme-linked immunosorbent assay (c-ELISA) of detecting serogroup-specific antibody is established based on major LSDV antigen A33. Serum samples (n = 605) were collected to optimize the c-ELISA from different areas. The cut-off value for the c-ELISA was estimate using percent inhibition (PI) values. The diagnostic performance of test including sensitivity (sn) and specificity (sp) were obtained by receiver operator characteristic (ROC) analysis. Among these analysis, > 57.61% PI value was accepted as cut-off of the c-ELISA, the diagnostic sn an diagnostic sp were reached to 96.4% and 98.5%, at > 95% confidence interval. These results show that the developed competitive ELISA is sensitive, specific, and reliable, which make it appropriate for serological investigation.

正痘病毒属病毒的A33和H3L蛋白是其成员共有的中和抗体的两个主要靶标.为检测鼠痘病毒(ectromelia virus,ECTV)A33和H3L蛋白同源物的免疫原性及抗体中和活性,以ECTV-Moscow株基因组DNA为模板,PCR扩增A3 3和H3L同源基因EVM135、EVM085目的序列,分别构建pET30a-EVM135、pET30-EVM085原核表达载体,转化Rosetta感受态细胞,IPTG诱导表达,利用镍层析柱纯化并进行逐步透析复性,免疫兔制备多克隆抗体.建立间接ELISA方法测定其抗体效价分别达1∶120 000和1∶360 000,Western blot和IFA证实该多克隆抗体具有良好的特异性和反应性;ECTV病毒中和试验表明抗EVM135多克隆抗体中和效价为1∶16,而抗EVM085多克隆抗体效价为1∶128.本研究通过高效表达EVM135和EVM085蛋白,并分析其免疫原性及抗体中和活性,为深入研究痘病毒致病和免疫机理,进而快速建立其诊断方法,为猴痘防控技术措施的研究奠定基础.

本研究从疑似爆发伪狂犬病(pseudorabies,PR)猪场死亡猪中分离到1株病毒,经PCR检测、主要毒力基因gB、gC、gD和gE测序及遗传关系分析,发现它与国内流行的PRV变异毒株具有相似的突变特征,氨基酸序列与HN-ZZ/Swine(MH321405)变异株亲缘关系最近,将其鉴定为伪狂犬病变异病毒(pseudorabies virus,PRV),并命名为PRVHN-2017株,发现该毒株在Vero细胞上具有较强的适应性.为进一步探讨PRV HN-2017株的致病性,将该变异株按不同剂量经滴鼻途径接种于45日龄的SPF猪,均先后出现了发热、抽搐、呼吸困难等猪伪狂犬病典型症状,其中高剂量感染组在7 d内全部死亡;RT-PCR检测证实该病毒毒株在体内分布较广,在扁桃体中病毒载量最高,其次是脾脏、肺脏、淋巴结、脑组织、肾脏和肝脏.这表明成功分离到1株PRV变异毒株,并证实该毒株对仔猪具有很强的致病性,能导致多种重要组织器官的不同程度的损害.

本研究旨在建立一种特异性检测牛结节性皮肤病病毒(LSDV)的LAMP快检方法,以用于该病临床早期诊断与监测.笔者根据LSDV的特异性基因序列,设计了数十套LAMP引物,经过筛选最终确定1套反应效率最高的引物,其位于LSDV095基因序列内.以实验室保存的PUC57-LSDV质粒作为阳性质控进行方法的优化与验证,基于不同的检测需求,分别建立了实时浊度LAMP检测方法、实时荧光LAMP检测方法及荧光可视化LAMP检测方法.优化后的3种LSDVLAMP方法灵敏度均可达20 copies/反应的靶基因,与WOAH推荐的实时荧光PCR方法(5 copies/反应)相近;特异性良好,与山羊痘病毒(GTPV)、绵羊痘病毒(SPPV)、小反刍兽疫病毒(PPRV)、赤羽病病毒(AKV)、蓝舌病病毒(BTV)及口蹄疫病毒(FMDV)均无交叉反应.其中,实时浊度法操作程序简单,实时荧光法反应快速(25 min内完成检测),荧光可视化法不依赖专用仪器及中心实验室.将所建方法应用于临床样本的检测,显示这3种方法均可特异性检测到LSDV,与实时荧光PCR方法检测结果一致性为100％,优于WOAH推荐的普通PCR方法.所建方法具有快速、特异、灵敏、操作简便且不依赖专用仪器等优点,可为LSDV的临床快速筛查提供技术支持.

细胞程序性死亡是一种受基因调控的细胞死亡方式,包括细胞凋亡、焦亡、坏死性凋亡、铁死亡、自噬等,这些多元化的细胞程序性死亡方式在病毒的复制和传播中发挥重要作用.其中,痘病毒通过编码大量的病毒蛋白(例如E3L、F1L等)参与介导痘病毒免疫逃逸,抵抗宿主细胞死亡,以此维持自身复制.本文综述了痘病毒E3L蛋白在调控细胞凋亡、焦亡、坏死性凋亡中的作用,深入剖析了 PKR、F1L和Zα结构域介导的E3L相关细胞程序性死亡分子机制,以期为痘病毒免疫逃逸机制探索、抗病毒药物开发等提供新思路.

The monkeypox epidemic has attracted global attention to poxviruses. The cytoplasmic replication of poxviruses requires extensive protein synthesis, challenging the capacity of the endoplasmic reticulum (ER). However, the role of the ER in the life cycle of poxviruses is unclear. In this study, we demonstrate that infection with the lumpy skin disease virus (LSDV), a member of the poxvirus family, causes ER stress in vivo and in vitro, further facilitating the activation of the unfolded protein response (UPR). Although UPR activation aids in the restoration of the cellular environment, its significance in the LSDV life cycle remains unclear. Furthermore, the significance of ER imbalance for viral replication is also unknown. We show that LSDV replication is hampered by an unbalanced ER environment. In addition, we verify that the LSDV replication depends on the activation of PERK‐eIF2α and IRE1‐XBP1 signaling cascades rather than ATF6, implying that global translation and reduced XBP1 cleavage are deleterious to LSDV replication. Taken together, these findings indicate that LSDV is involved in the repression of global translational signaling, ER chaperone transcription, and ATF6 cleavage from the Golgi into the nucleus, thereby maintaining cell homeostasis; moreover, PERK and IRE1 activation contribute to LSDV replication. Our findings suggest that targeting UPR elements may be applied in response to infection from LSDV or even other poxviruses, such as monkeypox.

Guanylate-binding proteins (GBPs) are highly expressed interferon-stimulated genes (ISGs) that play significant roles in protecting against invading pathogens. Although their functions in response to RNA viruses have been extensively investigated, there is limited information available regarding their role in DNA viruses, particularly poxviruses. Ectromelia virus (ECTV), a member of the orthopoxvirus genus, is a large double-stranded DNA virus closely related to the monkeypox virus and variola virus. It has been intensively studied as a highly effective model virus. According to the study, GBP2 overexpression suppresses ECTV replication in a dose-dependent manner, while GBP2 knockdown promotes ECTV infection. Additionally, it was discovered that GBP2 primarily functions through its N-terminal GTPase activity, and the inhibitory effect of GBP2 was disrupted in the GTP-binding-impaired mutant GBP2K51A. This study is the first to demonstrate the inhibitory effect of GBP2 on ECTV, and it offers insights into innovative antiviral strategies.

目的 克隆羊口疮病毒020基因,构建其重组真核表达质粒并转染HeLa细胞,分析020基因编码E3L蛋白的亚细胞定位,分析该蛋白生物信息学特征.方法 提取羊口疮病毒基因组,PCR扩增020基因并构建重组真核表达质粒,转染HeLa细胞,采用Western blot检测其在该细胞中的表达,免疫荧光法检测该蛋白的亚细胞定位.利用DNAstar软件分析不同毒株ORFV E3L氨基酸序列特点及其遗传演化关系;利用SOMPA软件分析其二级结构;利用SignalP4.0软件预测信号肽;利用TMHMM2.0软件预测跨膜结构;利用NetPhos 3.1预测磷酸化位点;利用NetNGlyc-1.0预测糖基化位点;应用IDEB和SYFPEITHI预测ORFV E3L蛋白的抗原表位.结果 成功克隆得到ORFV 020基因,全长549 bp,编码183个氨基酸;亚细胞定位显示该蛋白定位于细胞核和细胞质.生物信息学分析ORFV E3L蛋白α螺旋约占40.44％、β折叠约占5.46％、延伸链约占16.94％、无规则卷曲约占37.16％;该蛋白无信号肽和跨膜结构,可能存在15个磷酸化位点,7个N-糖基化位点,5个B细胞线性表位,2个CTL表位,3个Th细胞表位,3个B细胞和CTL联合表位,3个B细胞和Th细胞联合表位.结论 ORFV E3L蛋白定位于细胞核和细胞质,含有多个抗原表位,可能具有免疫原性.该蛋白高度保守,具有成为优势保护性抗原的潜力.为进一步揭示ORFV E3L蛋白的功能奠定基础,为ORFV诊断方法的建立及疫苗的研制提供了理论依据.

Poxviruses have been associated with humans for centuries. From smallpox to mpox to lumpy skin disease virus (LSDV), members of the poxvirus family have continued to threaten the lives of humans and domestic animals. A complete understanding of poxvirus-mediated cellular processes will aid in the response to challenges from the viruses. In this study, we demonstrate that LSDV infection results in an abnormal ultrastructure of the endoplasmic reticulum (ER) lumen in primary bovine embryonic fibroblast (BEF) cells, and we further show that an ER imbalance occurs in LSDV-infected BEF cells. Additionally, we believe that ER stress-related apoptosis plays a role in the late apoptosis of BEF cells infected with LSDV, primarily through the activation of the CCAAT/enhancer binding protein homologous protein (CHOP)-Caspase-12 signal. In addition to cell apoptosis, a further investigation showed that LSDV could also activate autophagy in BEF cells, providing additional insight into the exact causes of LSDV-induced BEF cell death. Our findings suggest that LSDV-induced BEF cell apoptosis and autophagy may provide new avenues for laboratory diagnosis of lumpy skin disease progression and exploration of BEF cell processes.

To investigate the effect of bovine G3BP1(bG3BP1)on the enzymatic activity of DNA recog-nition receptor cGAS,the total RNA from bovine blood lymphocytes was extracted and reversely tran-scribed into cDNA by RT-PCR and the bG3BP1 gene were cloned.Subsequently,the prokaryotic expression vector pET-28a-SUMO-bG3BP1 was constructed and transformed into competent E.coli cells.The recombi-nant protein bG3BP1 was purified by nickel column affinity chromatography and purified further after removing SUMO label proteins to reach high purity.Finally,the bG3BP1 was used for the enzymatic reac-tion of bovine cGAS(bcGAS)in vitro,and the product of 2'3'-cGAMP was detected by ELISA.The results showed that soluble bG3BP1 protein promoted the enzymatic reaction of bcGAS in vitro and increased the yield of the second messenger molecule 2'3'-cGAMP,which provided technical methods and research ideas for the large-scale production and application of 2'3'-cGAMP.

The recent spread of the monkeypox virus among humans has heightened concerns regarding orthopoxvirus infections. Consequently, conducting a comprehensive study on the immunobiology of the monkeypox virus is imperative for the development of effective therapeutics. Ectromelia virus (ECTV) closely resembles the genetic and disease characteristics of monkeypox virus, making it a valuable research tool for studying orthopoxvirus–host interactions. Guanylate-binding proteins (GBPs), highly expressed interferon-stimulated genes (ISGs), have antagonistic effects against various intracellular pathogenic microorganisms. Our previous research has shown that GBP2 has a mild but statistically significant inhibitory effect on ECTV infection. The presence of a significant number of molecules in the poxvirus genome that encode the host immune response raises questions about whether it also includes proteins that counteract the antiviral activity of GBP2. Using IP/MS and co-IP technology, we discovered that the poly(A) polymerase catalytic subunit (PAPL) protein of ECTV is a viral regulatory molecule that interacts with GBP2. Further studies have shown that PAPL antagonizes the antiviral activity of GBP2 by reducing its protein levels. Knocking out the PAPL gene of ECTV with the CRISPR/Cas9 system significantly diminishes the replication ability of the virus, indicating the indispensable role of PAPL in the replication process of ECTV. In conclusion, our study presents preliminary evidence supporting the significance of PAPL as a virulence factor that can interact with GBP2.

Intestinal organoids have emerged as powerful model systems for studying the complex structure and function of the intestine. However, there is a lack of widely applicable methods for the collection, labeling, and imaging of intestinal organoids. In this study, we developed a novel method for loading and labeling intestinal organoids, a method that efficiently collects the organoids and facilitates imaging of their three-dimensional (3D) structure. Based on this strainer platform, mouse intestinal organoids were adequately collected and immobilized, facilitating the immunolabeling workflow to target proteins of the organoids. After evaluation, the strainer size of 40 μm was considered to be more conducive to the collection and labeling of mouse intestinal organoids. More extensive research on organoids of multiple types and species origins will contribute to broadening the applicability of the methodology. Overall, our study proposes an innovative workflow for loading and analyzing intestinal organoids. The combination of a strainer-based collection method, fluorescent labeling, and 3D reconstruction provides valuable insights into the organization and complexity of these tissue models, thereby offering new avenues for investigating intestinal development, disease modeling, and drug discovery.

绵羊源爱知病毒D型(ovine Aichivirus D)是在国内绵羊中新发现的病毒,本研究根据绵羊源Aichivirus D 3D基因序列设计检测引物,通过反应体系和条件优化,成功建立了检测绵羊源Aichivirus D的TB Green染料法荧光RT-PCR方法,该方法特异性和稳定性良好,灵敏度高.对2020年4月-2021年5月采集自四川6个场253份绵羊粪便样本(健康羊的133份,腹泻羊的120份)进行检测,结果该病毒的平均检出率为8.7％,场阳性率为66.7％.其中,腹泻粪便样本中绵羊源Aichivirus D阳性率(17.5％)显著高于非腹泻粪便样本中绵羊源Aichivirus D阳性率(0.75％,P＜0.001).表明绵羊源Aichivirus D可能是引起以上地区绵羊腹泻的病原.从绵羊源Aichi-virus D 的阳性样本中成功克隆出大小为1 422 bp的13个完整的绵羊源Aichivirus D 3D基因,其核苷酸相似性为99.4％～100.0％.遗传演化分析发现这13株绵羊源Aichivirus D 3D基因与本实验室前期研究上传的绵羊源Ai-chivirus D 3D基因共同聚为单独的一个大支.本研究为绵羊源Aichivirus D的分子检测提供了一种新的方法和基础流行病学数据.

Schistosoma is a genus of parasitic trematodes that undergoes complex migration in final hosts, finally developing into adult worms, which are responsible for egg production and disease dissemination. Recent studies documented the importance of extracellular vesicles (EVs) in the regulation of host-parasite interactions. Herein, we investigated the microRNA (miRNA) profiles of EVs isolated from host plasma at different stages of Schistosoma japonicum infection (lung stage: 3 days post-infection (dpi), and liver stages: 14 and 21 dpi) to identify miRNA cargo potentially involved in the pathogenesis and immune regulation of schistosomiasis. Characterization of the isolated plasma EVs revealed their diameter to be approximately 100 nm, containing typical EV markers such as Hsp70 and Tsg101. Deep sequencing analysis indicated the presence of 811 known and 15 novel miRNAs with an increasing number of differential miRNAs from the lung stage (27 miRNAs) to the liver stages (58 and 96 miRNAs at 14 and 21 dpi, respectively) in the plasma EVs of infected mice compared to EVs isolated from the uninfected control. In total, 324 plasma EV miRNAs were shown to be co-detected among different stages of infection and the validation of selected miRNAs showed trends of abundance similar to deep sequencing analysis. For example, miR-1a-3p and miR-122-5p showed higher abundance, whereas miR-150-3p and miR-126a showed lower abundance in the plasma EVs of infected mice at 3, 14, and 21 dpi as compared to those of uninfected mice. In addition, bioinformatic analysis combined with PCR validation of the miRNA targets, particularly those associated with the immune system and parasitic infectious disease, indicated a significant increase in the expression of Gbp7 and Ccr5 in contrast to the decreased expression of Fermt3, Akt1 , and IL-12a . Our results suggested that the abundance of miRNA cargo of the host plasma EVs was related to the stages of Schistosoma japonicum infection. Further studies on the roles of these miRNAs may reveal the regulatory mechanism of the host-parasite interaction. Moreover, the differentially abundant miRNA cargo in host EVs associated with S. japonicum infection may also provide valuable clues for identifying novel biomarkers for schistosomiasis diagnosis.

Antibody development is the integral process of generating and characterizing an antibody. It commences by inoculating the antigen of interest into laboratory animals, allowing the immune system develops large quantities of antibodies. This was aimed at developing antibodies against the virion of Goatpox and Sheeppox virus vaccines. The ability of Goatpox and Sheeppox vaccines was assessed. Regarding this study, the antibody titers against both Goatpox and Sheeppox viruses was increased in the same manner. The amount of IgG was determined to be 2.29 μg/μl and 2.18 μg/μl against virions of Goatpox virus and Sheeppox respectively. The purified IgG was analyzed by SDS-PAGE. Different bands of the purified antibodies were clearly visualized, and the molecular weight of IgG was estimated to be 67 kDa and 25 kDa. Additionally, antigen/antibody binding was confirmed by Western blot using GTPV A27 antigen. No significant differences in antibody titers were observed between the two groups (p < 0, 05).