Veterinary microbiology最新文献_第10页

Bovine tracheal organoids for studying Mycoplasma bovis respiratory infections 用于研究牛支原体呼吸道感染的牛气管器官组织。

IF 2.4 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2025-01-01 DOI: 10.1016/j.vetmic.2024.110340

Chintha K. Premachandre , Pin Shie Quah , Bang Manh Tran , Elizabeth Vincan , Georgia Deliyannis , Chinn Yi Wong , Andrés Diaz-Méndez , David C. Jackson , Patrick C. Reading , Glenn F. Browning , Paola K. Vaz , Nadeeka K. Wawegama

In vitro three-dimensional organoid models simulate key aspects of the structure and function of in vivo organs and have been used to study physiology, host-pathogen interactions, pathogenesis and pharmacodynamics. Although most organoid studies have been developed using human or mouse tissues, recent advancements have enabled the establishment of intestinal and respiratory tract organoids from domestic animal samples. Mycoplasma bovis causes chronic respiratory tract infections in cattle with significant health and economic consequences. The pathogenesis and virulence factors of M. bovis have been studied in several in vitro infection models, but the use of organoids has not been examined previously. In this study, we assessed the feasibility of using a matrix-embedded bovine tracheal organoid system to study respiratory infections with M. bovis. Bovine tracheal organoids were inoculated with M. bovis strain MbovMil and incubated for 72 hours to investigate the ability of M. bovis to proliferate, attach and invade the organoids. M. bovis was able to infect the organoids, resulting in a mean 260-fold increase in the titre of viable M. bovis by 72 hours post-inoculation. Examination of the infected organoids using transmission electron microscopy revealed the presence of mycoplasmas within the organoid cells and membrane bound clusters of M. bovis inside the intercellular junctions. Our findings indicate that bovine tracheal organoids can be used as a model system for studying respiratory tract infections caused by M. bovis.

体外三维类器官模型模拟了体内器官结构和功能的关键方面，已被用于研究生理学、宿主-病原体相互作用、致病机理和药效学。虽然大多数类器官研究都是利用人体或小鼠组织开发的，但最近的研究进展已使利用家畜样本建立肠道和呼吸道类器官成为可能。牛支原体会导致牛慢性呼吸道感染，对健康和经济造成重大影响。牛支原体的致病机理和毒力因子已在多个体外感染模型中进行了研究，但此前还未对有机体的使用进行过研究。在本研究中，我们评估了使用基质包埋的牛气管类器官系统研究牛海绵状芽孢杆菌呼吸道感染的可行性。牛气管类器官接种牛杆菌菌株 MbovMil 并培养 72 小时，以研究牛杆菌增殖、附着和侵入类器官的能力。牛海绵状芽孢杆菌能够感染器官组织，接种后 72 小时，存活的牛海绵状芽孢杆菌滴度平均增加了 260 倍。使用透射电子显微镜对受感染的类器官进行检查后发现，类器官细胞内存在支原体，细胞间连接处存在与膜结合的牛曲霉菌团。我们的研究结果表明，牛气管类器官可用作研究牛海绵状芽孢杆菌引起的呼吸道感染的模型系统。

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引用次数: 0

IFN-mediated lncRNA-ISL promotes SVV infection through G1P3 ifn介导的lncRNA-ISL通过G1P3促进SVV感染。

IF 2.4 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2024-12-25 DOI: 10.1016/j.vetmic.2024.110318

Chen Wang , Yijun Yang , Xiwang Yang , Qiyue Yang , Rui Liu , Wenting Li , Xiao Liu

lncRNAs play important regulatory roles in almost every aspect of physiological processes. However, the mechanisms by which animal-encoded lncRNAs regulate the interaction of viral infection with host antiviral immunity are unknown. To explore the mechanisms of lncRNA regulation of SVV infection and interferon responses. We performed complete transcriptome sequencing analysis of porcine kidney 15 (PK-15) after infection with SVV-1 strain and IFN-α treatment, and identified and screened the sequencing data to obtain potential functional lncRNA-ISL. selected genes were knocked down using CRISPR/Cas9 guide RNAs (gRNAs), and the results of the sequencing were monitored by qRT-PCR and protein blotting in multiple cell lines for selected gene mRNAs and their proteins as well as SVV infection. The results showed that 68 lncRNAs were significantly altered by IFN-α and 176 lncRNAs were significantly altered after SVV infection. We found that lncRNA-ISL gRNA significantly inhibited SVV infection compared to negative gRNA control. The expression of the antiviral ISG G1P3 was significantly increased following lncRNA-ISL gRNA editing compared to negative gRNA control in SVV-infected PK-15 cells. We observed that lncRNA-ISL regulation of SVV was independent of JAK-STAT signaling and not associated with G1P3 DNA methylation. Finally, we confirmed that the regulatory effect of lncRNA-ISL on G1P3 occurs during the initial transcription.

lncrna几乎在生理过程的各个方面都发挥着重要的调节作用。然而，动物编码lncrna调节病毒感染与宿主抗病毒免疫相互作用的机制尚不清楚。探讨lncRNA调控SVV感染及干扰素应答的机制。我们对感染SVV-1株和IFN-α处理后的猪肾15 （PK-15）进行了完整的转录组测序分析，并对测序数据进行了鉴定和筛选，获得了潜在的功能性lncRNA-ISL。利用CRISPR/Cas9引导rna （gRNAs）敲低所选基因，在多个细胞系中采用qRT-PCR和蛋白印迹检测所选基因mrna及其蛋白的测序结果以及SVV感染情况。结果显示，68个lncrna被IFN-α显著改变，176个lncrna在SVV感染后显著改变。我们发现与阴性gRNA对照相比，lncRNA-ISL gRNA显著抑制SVV感染。在svv感染的PK-15细胞中，与gRNA阴性对照相比，lncRNA-ISL gRNA编辑后，抗病毒ISG G1P3的表达显著增加。我们观察到lncRNA-ISL对SVV的调控独立于JAK-STAT信号，与G1P3 DNA甲基化无关。最后，我们证实lncRNA-ISL对G1P3的调控作用发生在初始转录过程中。

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引用次数: 0

Genetic diversity of Brucella abortus strains from cattle and water buffalo in the Italian province of Caserta 意大利卡塞塔省牛和水牛产布鲁氏菌菌株的遗传多样性

IF 2.4 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2024-12-01 DOI: 10.1016/j.vetmic.2024.110314

Luigi Orrù , Antonella Lamontanara , Celestina Mascolo , Giorgia Borriello , Rubina Paradiso , Anna Cerrone , Paolo Coppa , Manuela Tittarelli , Carlo Ferrara , Esterina De Carlo , Giorgio Galiero , Alessandra Martucciello

Brucella abortus is an important zoonotic pathogen that infects cattle and buffaloes. In Italy the application of eradication programs combined with vaccination has greatly contributed to reduce the incidence of brucellosis. However, despite the eradication programs brucellosis continue to persist with a high endemicity in some areas of Italy including the province of Caserta. In the present study the genomes of 44 B. abortus strains isolated from different outbreak cases that affected the province of Caserta were sequenced to characterize the genetic diversity of the Brucella strains circulating during the period from 2017 to 2022. The relatedness among these isolates was compared to 52 publicly available genomes of Italian B. abortus isolates. The results highlighted a low genetic diversity in the B. abortus population present in the Caserta area with the persistence of a low number of Brucella lineages and suggests a reduction in circulating lineages in recent years due to eradication programs.

流产布鲁氏菌是一种重要的感染牛、水牛的人畜共患病原体。在意大利，根除计划与疫苗接种相结合的应用大大有助于减少布鲁氏菌病的发病率。然而，尽管实施了根除计划，布鲁氏菌病在意大利的一些地区，包括卡塞塔省，仍然保持着很高的流行率。本研究对从卡塞塔省不同暴发病例中分离的44株流产布鲁氏菌进行了基因组测序，以表征2017年至2022年流行的布鲁氏菌菌株的遗传多样性。将这些分离株的亲缘性与52个公开获得的意大利abortus分离株基因组进行比较。结果强调了在Caserta地区存在的B. abortus种群的低遗传多样性，以及持续存在的低数量的布鲁氏菌谱系，并表明近年来由于根除计划而减少了循环谱系。

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引用次数: 0

Identification and characterization of biosynthetic loci of lipooligosaccharide and capsular polysaccharide in Avibacterium paragallinarum 副翼鸟杆菌低脂多糖和荚膜多糖生物合成位点的鉴定与表征

IF 2.4 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2024-12-01 DOI: 10.1016/j.vetmic.2024.110317

Ling Chen , Juan Sun , Jialian Hu , Ye Tian , Pengfei Du , Qianqian Guo , Chenghuai Yang , Qianyi Zhang , Saixiang Feng , Ming Liao

Infectious coryza is an acute respiratory disease in chickens caused by Avibacterium paragallinarum. Lipooligosaccharides (LOSs) and capsular polysaccharides are important components of Av. paragallinarum. Herein, we identified that gene cluster L6 and two genes waaF, waaQ were associated with LOS synthesis, and two genes acbD and ccbF1 were involved in capsular synthesis. Mutant and complementary strains of these genes were generated by natural transformation. Wild-type strains produced LOS that yielded an upper and lower band. In comparison, ΔwaaQ and ΔwaaF yielded a truncated lower band and lacked the upper band, while ΔL6 did not exhibit the upper band, and the lower band was identical to that of the wild-type strain. The survival rates of wild-type strain, ΔwaaF, ΔwaaQ, and ΔL6 in chicken serum were 4.89 % ± 0.27 %, 0.0013 % ± 0.0002 %, 0.43 % ± 0.05 %, and 3.1 % ± 0.35 %, respectively. Notably, the resistances of ΔwaaF, ΔwaaQ, and ΔL6 to chicken serum were significantly lower than that of parent strain. By contrast, the survival rate of the ΔacbD strain was 55.17 % ± 0.61 %, and its resistance to chicken serum was significantly higher than that of the wild-type strain (p < 0.001). Deletion of the waaF, waaQ, L6, acbD, and ccbF1 genes resulted in enhanced formation of biofilm without altering immunogenicity in chickens. The ΔwaaF, ΔwaaQ, and ΔccbF1 strains exhibited heightened susceptibility to fowlicidin-2. Furthermore, ΔwaaF, ΔacbD, and ΔccbF1 strains shown a decrease in pathogenicity (p < 0.05). These results are valuable for advancing research on the pathogenesis of Av. paragallinarum.

传染性鼻炎是一种由副鸡Avibacterium paragallinarum引起的急性呼吸道疾病。低脂多糖（LOSs）和荚膜多糖是副藻的重要成分。在此，我们发现基因簇L6和两个基因waaF、waaQ与LOS合成有关，两个基因acbD和ccbF1与荚膜合成有关。这些基因的突变株和互补株是通过自然转化产生的。野生型菌株产生的LOS产生上、下两个波段。相比之下，ΔwaaQ和ΔwaaF有截断的下带，缺少上带，而ΔL6没有上带，下带与野生型菌株相同。野生型菌株的存活率、ΔwaaFΔwaaQ,和哈佛Δ鸡血清4.89  % %±0.27,0.0013±0.0002  % %,0.43±0.05  % %,分别为3.1±0.35  % %。值得注意的是，ΔwaaF、ΔwaaQ和ΔL6对鸡血清的抗性显著低于亲本菌株。与此相反，ΔacbD菌株的存活率为55.17 %±0.61 %，对鸡血清的抗性显著高于野生型菌株(p <；0.001)。缺失waaF、waaQ、L6、acbD和ccbF1基因可增强鸡的生物膜形成，但不改变免疫原性。ΔwaaF、ΔwaaQ和ΔccbF1菌株对禽粪素-2敏感性增高。此外，ΔwaaF、ΔacbD和ΔccbF1菌株的致病性也有所下降(p <；0.05)。这些结果对进一步深入研究副藻弧菌的发病机制具有一定的参考价值。

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引用次数: 0

Essential role of the interaction between classical swine fever virus core protein and cellular MYO1B in viral components transport to exosomes and titer maintenance 经典猪瘟病毒核心蛋白与细胞 MYO1B 之间的相互作用在病毒成分向外泌体运输和滴度维持中的重要作用

IF 2.4 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2024-11-24 DOI: 10.1016/j.vetmic.2024.110315

Xi Bao , Tenhan Zhuang , Yue Xu , Li Chen , Lei Feng , Huochun Yao

Classical swine fever (CSF) is a severe disease caused by the highly contagious CSFV. Our previous study demonstrated that exosomes from CSFV-infected cells contained significant amounts of viral genome and Core (C) protein and were infectious. To further elucidate the mechanisms underlying the formation of these infectious exosomes, we investigated the intracellular transport of the C protein in this study. We first identified the synchronized transport of the C protein and viral genome to exosomes, distinguishing it from other structural proteins. This suggests that the C protein likely binds to the viral genome and is transported to exosomes as a nucleocapsid. Subsequently, Co-IP and co-localization experiments confirmed the interaction between the host Myosin 1B (MYO1B) protein and the C protein. Key interaction sites were identified by generating and analyzing various C protein point mutations and truncation variants. The results indicate that specific sites at the N-terminus of the C protein significantly impact its interaction with MYO1B. Ultimately, by modulating MYO1B expression, we found that MYO1B knockdown significantly reduced the C protein and viral genome content in exosomes, leading to a decrease in CSFV titers. These findings underscore the critical role of MYO1B in facilitating the transport of the C protein and viral genome into exosomes during CSFV infection. Overall, this study explores the mechanism of infectious exosome formation during CSFV infection, revealing the critical role of the host MYO1B in this process. This is the first study to identify the involvement of MYO1B in viral infection, not only offering important insights into host-virus interactions but also identifying a new target for antiviral drug development.

典型猪瘟（CSF）是一种由高度传染性的 CSFV 引起的严重疾病。我们之前的研究表明，CSFV 感染细胞的外泌体含有大量病毒基因组和核心（C）蛋白，具有传染性。为了进一步阐明这些传染性外泌体的形成机制，我们在本研究中调查了 C 蛋白的胞内转运。我们首先确定了 C 蛋白与病毒基因组同步转运到外泌体，将其与其他结构蛋白区分开来。这表明，C蛋白很可能与病毒基因组结合，并作为核壳被转运到外泌体。随后，Co-IP 和共定位实验证实了宿主肌球蛋白 1B (MYO1B) 蛋白与 C 蛋白之间的相互作用。通过生成和分析各种 C 蛋白点突变和截断变体，确定了关键的相互作用位点。结果表明，C 蛋白 N 端的特定位点对其与 MYO1B 的相互作用有显著影响。最终，通过调节 MYO1B 的表达，我们发现敲除 MYO1B 能显著减少外泌体中的 C 蛋白和病毒基因组含量，从而降低 CSFV 滴度。这些发现强调了 MYO1B 在 CSFV 感染过程中促进 C 蛋白和病毒基因组转运到外泌体中的关键作用。总之，这项研究探索了 CSFV 感染过程中传染性外泌体的形成机制，揭示了宿主 MYO1B 在这一过程中的关键作用。这是首次发现 MYO1B 参与病毒感染的研究，不仅为宿主与病毒之间的相互作用提供了重要见解，还为抗病毒药物的开发找到了新的靶点。

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引用次数: 0

PD-1 blockade synergizes with ascorbic acid to restore the activation and anti-viral immune functions of CD8+ T cells in a mouse model of BVDV infection PD-1阻断剂与抗坏血酸协同作用，恢复BVDV感染小鼠模型中CD8+ T细胞的活化和抗病毒免疫功能

IF 2.4 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2024-11-24 DOI: 10.1016/j.vetmic.2024.110316

Yang Li , Zhibo Zhao , Linru He , Yue Liang , Meng Liu , Meiqi Dong , Zehao Li , Bin Xu , Zecai Zhang , Yulong Zhou , Yu Liu , Zhanbo Zhu , Jianjun Zhao

Bovine viral diarrhea virus (BVDV) can cause typical peripheral lymphopenia and inhibit CD8⁺ T-cell activation and proliferation. Programmed death-1 (PD-1) blockade has been shown to increase CD8⁺ T-cell activation during cytopathic (CP) BVDV infection but not non-cytopathic (NCP) BVDV. Notably, ascorbic acid (AA) restores lymphocyte count and activation during SARS-CoV-2 and influenza virus infections and has a synergistic effect with PD-1 blockade to improve antitumor CD8⁺ T-cell activity. Nevertheless, it remains unclear whether AA exerts an immunomodulatory effect on the activation and proliferation of CD8⁺ T cells during BVDV infection, especially NCP BVDV infection, or whether PD-1 blockade and AA exert a synergistic effect in regulating CD8⁺ T cell antiviral activities. In this study, we found that BVDV infection significantly decreased AA levels in serum and CD8⁺ T cells in a BALB/c mouse model. Interestingly, AA supplementation dramatically downregulated PD-1 expression, restored the activation and proliferation of CD8⁺ T cells, inhibited viral replication, ameliorated BVDV-induced histological lesions, and upregulated the expression of CD25 and p-ERK. More importantly, we also found a synergistic effect of PD-1 blockade with AA in restoring the activation and proliferation of CD8⁺ T cells during CP BVDV infection. However, during NCP BVDV infection, a synergistic effect of PD-1 blockade and AA led to the inhibition of viral replication and the promotion of IFN-γ production. Our findings provided new insights into the immunopathological mechanisms of BVDV and the potential value of anti-viral strategies based on AA treatment alone or in combination with PD-1 blockade.

牛病毒性腹泻病毒（BVDV）可引起典型的外周淋巴细胞减少，抑制CD8+ t细胞的活化和增殖。程序性死亡-1 （PD-1）阻断已被证明在细胞病变（CP） BVDV感染期间增加CD8+ t细胞的激活，而非细胞病变（NCP） BVDV则没有。值得注意的是，抗坏血酸（AA）在SARS-CoV-2和流感病毒感染期间恢复淋巴细胞计数和活化，并与PD-1阻断具有协同作用，以提高抗肿瘤CD8+ t细胞活性。然而，目前尚不清楚AA是否在BVDV感染过程中对CD8+ T细胞的激活和增殖具有免疫调节作用，特别是在NCP BVDV感染过程中，也不清楚PD-1阻断和AA是否在调节CD8+ T细胞抗病毒活性方面具有协同作用。在本研究中，我们发现BVDV感染显著降低了BALB/c小鼠模型中血清和CD8+ T细胞中的AA水平。有趣的是，补充AA可显著下调PD-1的表达，恢复CD8+ T细胞的活化和增殖，抑制病毒复制，改善bvdv诱导的组织学病变，上调CD25和p-ERK的表达。更重要的是，我们还发现PD-1阻断与AA在CP BVDV感染期间恢复CD8+ T细胞的激活和增殖方面具有协同作用。然而，在NCP BVDV感染期间，PD-1阻断和AA的协同作用导致病毒复制受到抑制，IFN-γ的产生得到促进。我们的研究结果为BVDV的免疫病理机制以及基于AA单独治疗或联合PD-1阻断的抗病毒策略的潜在价值提供了新的见解。

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引用次数: 0

Dihydrolipoamide acetyltransferase is a key factor mediating adhesion and invasion of host cells by Mycoplasma synoviae 二氢脂酰胺乙酰转移酶是滑膜支原体粘附和侵入宿主细胞的关键因素。

IF 2.4 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2024-11-16 DOI: 10.1016/j.vetmic.2024.110297

Haiyun Ma, Yunhai Zhao, Xiaoxiao He, Qing Wang, Yuting Zhang, Xiaoyong Xing, Xiaochun Wu, Guomei Quan, Shijun Bao

Mycoplasma synoviae is a significant avian pathogen responsible for chronic respiratory diseases, arthritis, and infectious synovitis in chickens and turkeys. These infections result in substantial economic losses to the global poultry industry. Dihydrolipoamide acetyltransferase (E2) is a multifunctional protein that plays an indispensable role in energy metabolism and redox balance and is also a key virulence factor of various pathogens. In this study, we used the avian pathogen M. synoviae as a model to identify the role of the E2 protein in the colonization and invasion of host cells. First, we prepared the polyclonal antibody of recombinant E2 (rE2) protein and found that the rE2 antibody had a strong complement-activating ability. E2 was found to be distributed in the cytoplasm and cell membrane of M. synoviae by immunoelectron microscopy. E2 localized on the cell membrane is a key factor in the adhesion of M. synoviae and has good immunogenicity. Enzyme-linked immunosorbent assay showed that the binding of rE2 to membrane proteins of chicken embryo fibroblasts (DF-1) was dose-dependent, and antiserum effectively inhibited this binding ability. Furthermore, E2 interacted with various components of the host extracellular matrix (ECM) and promoted the conversion of plasminogen to plasmin through terephthalic acid (tPA). In addition, E2 can enhance the ability of M. synoviae to invade DF-1 cells, which was significantly reduced after treatment with anti-E2 serum. These results indicate that E2 is an adhesion- and invasion-related protein and may be involved in the pathogenesis of M. synoviae, which provides new ideas for studying the pathogenesis of M. synoviae and preparing subunit vaccines.

滑膜支原体是一种重要的禽类病原体，可导致鸡和火鸡的慢性呼吸道疾病、关节炎和传染性滑膜炎。这些感染给全球家禽业造成了巨大的经济损失。二氢脂酰胺乙酰转移酶（E2）是一种多功能蛋白质，在能量代谢和氧化还原平衡中发挥着不可或缺的作用，同时也是各种病原体的关键毒力因子。在本研究中，我们以禽类病原体M. synoviae为模型，确定了E2蛋白在宿主细胞定殖和入侵中的作用。首先，我们制备了重组E2（rE2）蛋白的多克隆抗体，发现rE2抗体具有很强的补体激活能力。免疫电镜发现，E2分布在滑膜贻贝的细胞质和细胞膜上。定位于细胞膜上的 E2 是滑膜杆菌粘附的关键因素，具有良好的免疫原性。酶联免疫吸附试验表明，rE2与鸡胚成纤维细胞（DF-1）膜蛋白的结合具有剂量依赖性，抗血清能有效抑制这种结合能力。此外，E2 与宿主细胞外基质（ECM）的各种成分相互作用，并通过对苯二甲酸（tPA）促进纤溶酶原向纤溶酶的转化。此外，E2 还能增强滑膜贻贝侵袭 DF-1 细胞的能力，而用抗 E2 血清处理后，这种侵袭能力显著降低。这些结果表明，E2是一种与粘附和侵袭相关的蛋白，可能参与了滑膜霉菌的发病机制，这为研究滑膜霉菌的发病机制和制备亚单位疫苗提供了新思路。

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引用次数: 0

Chlamydia psittaci infection induces IFN-I and IL-1β through the cGAS-STING-IRF3/NLRP3 pathway via mitochondrial oxidative stress in human macrophages 鹦鹉热衣原体感染通过线粒体氧化应激在人巨噬细胞中通过 cGAS-STING-IRF3/NLRP3 途径诱导 IFN-I 和 IL-1β

IF 2.4 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2024-11-16 DOI: 10.1016/j.vetmic.2024.110292

Hongyu Yang , Peiyuan Sun , Shi Zhou , Yuanyuan Tang , Sijia Li , Weiwei Li , Xiang Yu , Hanying Liu , Yimou Wu

Chlamydia psittaci (C. psittaci) is a multi-host pathogen that elicits robust innate immune responses in macrophages. Chlamydiae target host mitochondria to manipulate the cellular fate and metabolic functions. However, the effect of C. psittaci on the host mitochondria remains obscure. This study investigated how C. psittaci, post-infection in human macrophages, induces mitochondrial oxidative stress and damage to activate the cGAS-STING-IRF3/NLRP3 pathway for IFN-I and IL-1β production. Results demonstrate that C. psittaci increased mitochondrial ROS (mtROS) production. This induced the release of oxidized mitochondrial DNA (mtDNA) into the cytoplasm of macrophages. It also augmented IFN-I and IL-1β production dependent on the cGAS-STING pathway. Macrophages pre-treated with mtROS inhibitor mito-TEMPO displayed reduced oxidized mtDNA. This consequently lowered IFN-I and IL-1β production via the cGAS-STING pathway induced by C. psittaci. Additionally, we found that mtROS production may inhibit C. psittaci proliferation through the synergistic action of IFN-I and IL-1β. In conclusion, our study reveals that C. psittaci induces mtROS production leading to mtDNA release. This activates the cGAS-STING-IRF3/NLRP3 pathway to increase IFN-I and IL-1β production. This study elucidates a novel mechanism of bacterial pathogen activation in the cGAS-STING pathway. This reveals the molecular mechanisms underlying the immune response to C. psittaci infection and proposes potential targets for the treatment of C. psittaci related diseases.

鹦鹉热衣原体（C. psittaci）是一种多宿主病原体，可引起巨噬细胞强烈的先天性免疫反应。衣原体以宿主线粒体为目标，操纵细胞的命运和代谢功能。然而，鹦鹉热衣原体对宿主线粒体的影响仍不明显。本研究调查了人巨噬细胞感染 C. psittaci 后如何诱导线粒体氧化应激和损伤，从而激活 cGAS-STING-IRF3/NLRP3 通路，产生 IFN-I 和 IL-1β。结果表明，鹦鹉热杆菌增加了线粒体 ROS（mtROS）的产生。这诱导氧化线粒体 DNA（mtDNA）释放到巨噬细胞的细胞质中。它还增强了依赖于 cGAS-STING 通路的 IFN-I 和 IL-1β 的产生。经 mtROS 抑制剂 mito-TEMPO 预处理的巨噬细胞显示出氧化的 mtDNA 减少。这就降低了猫疫病通过 cGAS-STING 途径诱导的 IFN-I 和 IL-1β 的产生。此外，我们还发现，mtROS 的产生可通过 IFN-I 和 IL-1β 的协同作用抑制鹦鹉热杆菌的增殖。总之，我们的研究揭示了鹦鹉热嗜血杆菌会诱导 mtROS 的产生，从而导致 mtDNA 的释放。这激活了 cGAS-STING-IRF3/NLRP3 通路，增加了 IFN-I 和 IL-1β 的产生。这项研究阐明了细菌病原体在 cGAS-STING 通路中被激活的新机制。这揭示了猫疫病感染免疫反应的分子机制，并提出了治疗猫疫病相关疾病的潜在靶点。

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引用次数: 0

Type I-E CRISPR-Cas system regulates fimZY and T3SS1 genes expression in Salmonella enterica serovar Pullorum I-E型CRISPR-Cas系统调控普拉伦沙门氏菌肠炎血清中fimZY和T3SS1基因的表达。

IF 2.4 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2024-11-15 DOI: 10.1016/j.vetmic.2024.110301

Kai Zhang , Pengyu Wang , Shanshan Li , Xiaolei Xie , Zhenyu Wang , Yang Li , Xinan Jiao , Qiuchun Li

Clustered regularly interspaced short palindromic repeats and associated Cas proteins (CRISPR-Cas) provide prokaryotes with adaptive immunity against invasion by plasmids or phages. In Salmonella, the type I-E CRISPR-Cas system is typically considered silent in immunity against foreign genetic elements. To elucidate the role of the CRISPR-Cas system, we chose Salmonella enterica serovar Pullorum S06004 as a model organism due to its four spacers and well-defined biological characteristics observed in previous studies. Western blot analysis revealed expression of Cas3 in S06004 cultured in vitro, but plasmid transformation assays demonstrated that both wild-type (WT) and S06004 strains overexpressing LeuO (a positive regulator of CRISPR-Cas) showed no immunity against the target plasmid. RNA-Seq analysis detected significant downregulation of the fim cluster, encoding type I fimbriae, and T3SS1-related genes in the cas cluster mutant compared to the WT. This downregulation was further confirmed in mutants of CR1 and individual cas genes by qRT-PCR. Consequently, mutants of CR1 and cas clusters exhibited decreased invasion of chicken hepatocellular carcinoma cells. The consistent regulation of T3SS1 genes by the CRISPR-Cas system in S. Pullorum, S. Enteritidis, and S. Typhimurium indicates a common role for the type I-E CRISPR-Cas system in promoting bacterial virulence. However, the specific molecular mechanisms underlying this regulation require further investigation.

成簇的有规则间隔短回文重复序列和相关的 Cas 蛋白（CRISPR-Cas）为原核生物提供了对抗质粒或噬菌体入侵的适应性免疫。在沙门氏菌中，I-E型CRISPR-Cas系统通常被认为在对外来遗传因子的免疫中保持沉默。为了阐明CRISPR-Cas系统的作用，我们选择了肠炎沙门氏菌（Salmonella enterica serovar Pullorum S06004）作为模式生物，因为在以前的研究中观察到了它的四个间隔和明确的生物学特征。Western 印迹分析显示，体外培养的 S06004 中表达了 Cas3，但质粒转化试验表明，野生型（WT）和过表达 LeuO（CRISPR-Cas 的正调控因子）的 S06004 菌株对目标质粒没有免疫力。与 WT 相比，RNA-Seq 分析检测到 cas 簇突变体中编码 I 型缘毛的 fim 簇和 T3SS1 相关基因显著下调。这种下调在 CR1 突变体和单个 cas 基因的 qRT-PCR 中得到了进一步证实。因此，CR1和cas基因簇突变体对鸡肝癌细胞的侵袭能力下降。T3SS1基因在S. Pullorum、S. Enteritidis和S. Typhimurium中受到CRISPR-Cas系统的一致调控，这表明I-E型CRISPR-Cas系统在促进细菌毒力方面发挥着共同的作用。然而，这种调控的具体分子机制还需要进一步研究。

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引用次数: 0

Mesomycoplasma (Mycoplasma) ovipneumoniae dihydrolipoamide dehydrogenase is an immunogenic plasminogen binding protein and a putative adhesin 卵肺中支原体（支原体）二氢脂酰胺脱氢酶是一种免疫原性血浆蛋白结合蛋白，也是一种假定的粘附蛋白。

IF 2.4 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology

Pub Date : 2024-11-12 DOI: 10.1016/j.vetmic.2024.110302

Jiazhen Ge , Tongtong Tian , Yijian Liu , Xuerui Li , Qianqian Li , Guodong Song , Pengcheng Gao , Fuying Zheng , Yuefeng Chu

The interaction of Mesomycoplasma (Mycoplasma) ovipneumoniae (M. ovipneumoniae) with host cells is a pivotal step in the infection process, underlining the necessity to develop vaccines and therapeutic approaches targeting the pathogen's key invasion mechanisms. The bacterium's capacity for adherence, invasion, and subsequent evasion of the host immune response underpins its pathogenicity, rendering adherence genes feasible vaccine targets. This study focuses on pyruvate dehydrogenase complex component E3 (PdhD), a membrane-anchored surface protein implicated in these pathogenic processes. Bioinformatics analysis reveals the conservation of PdhD sequence within M. ovipneumoniae. Membrane protein extraction, immunoblotting and ELISA assay have confirmed the presence of PdhD on the M. ovipneumoniae surface and cytoplasm, suggesting its multifunctionality. Our research employed antibody inhibition assays to characterize the bacterial adhesion suppression by anti-PdhD antibodies, complemented by bactericidal complement assays, supporting its candidacy as a putative vaccine target. The ELISA binding assay substantiated that PdhD binded to plasminogen (Plg) in a dose-dependent manner. Notably, PdhD is also involved in biofilm formation. The inhibitory effect of anti-PdhD sera on biofilm formation is congruent with novel therapeutic strategies targeting related mycoplasmas. This study reports the characterization of the first virulence-associated protein PdhD of M. ovipneumoniae and suggests its potential as a vaccine target to combat M. ovipneumoniae infection.

卵巢肺炎中支原体（M. ovipneumoniae）与宿主细胞的相互作用是感染过程中的关键步骤，因此有必要针对病原体的关键入侵机制开发疫苗和治疗方法。该细菌的粘附、入侵和随后逃避宿主免疫反应的能力是其致病性的基础，这使得粘附基因成为可行的疫苗靶标。本研究的重点是丙酮酸脱氢酶复合物成分 E3（PdhD），这是一种与这些致病过程有关的膜锚定表面蛋白。生物信息学分析揭示了 PdhD 序列在 M. ovipneumoniae 中的保守性。膜蛋白提取、免疫印迹和酶联免疫吸附试验证实了 PdhD 存在于卵膜肺炎霉菌的表面和细胞质中，表明其具有多功能性。我们的研究采用了抗体抑制试验来描述抗 PdhD 抗体抑制细菌粘附的特性，并辅以杀菌补体试验，支持其作为潜在疫苗靶点的候选资格。ELISA 结合试验证实，PdhD 与纤溶酶原（Plg）的结合具有剂量依赖性。值得注意的是，PdhD 还参与了生物膜的形成。抗 PdhD 血清对生物膜形成的抑制作用与针对相关支原体的新型治疗策略是一致的。本研究报告了卵肺霉菌第一个毒力相关蛋白 PdhD 的特征，并提出了其作为抗卵肺霉菌感染疫苗靶点的潜力。

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引用次数: 0