Virulence最新文献

{"title":"Extracellular vesicles from virulent <i>P. brasiliensis</i> induce TLR4 and dectin-1 expression in innate cells and promote enhanced Th1/Th17 response.","authors":"Bruno Montanari Borges, Monique Gama de Santana, Nycolas Willian Preite, Valéria de Lima Kaminski, Gabriel Trentin, Fausto Almeida, Flávio Vieira Loures","doi":"10.1080/21505594.2024.2329573","DOIUrl":"10.1080/21505594.2024.2329573","url":null,"abstract":"<p><p>Extracellular vesicles (EVs) are membrane-enclosed nanoparticles that transport several biomolecules and are involved in important mechanisms and functions related to the pathophysiology of fungal diseases. EVs from <i>Paracoccidioides brasiliensis</i>, the main causative agent of Paracoccidioidomycosis (PCM), modulate the immune response of macrophages. In this study, we assessed the EVs proteome from a virulent <i>P. brasiliensis</i> isolated from granulomatous lesions and compared their immunomodulatory ability with EVs isolated from the fungus before the animal passage (control EVs) when challenging macrophages and dendritic cells (DCs). Proteome showed that virulent EVs have a higher abundance of virulence factors such as GP43, protein 14-3-3, GAPDH, as well as virulence factors never described in PCM, such as aspartyl aminopeptidase and a SidJ analogue compared with control EVs. Virulent extracellular vesicles induced higher expression of TLR4 and Dectin-1 than control EVs in macrophages and dendritic cells (DCs). In opposition, a lower TLR2 expression was induced by virulent EVs. Additionally, virulent EVs induced lower expression of CD80, CD86 and TNF-α, but promoted a higher expression of IL-6 and IL-10, suggesting that EVs isolated from virulent <i>P. brasiliensis</i>-yeast promote a milder DCs and macrophage maturation. Herein, we showed that EVs from virulent fungi stimulated a higher frequency of Th1/Tc1, Th17, and Treg cells, which gives new insights into fungal extracellular vesicles. Taken together, our results suggest that <i>P. brasiliensis</i> utilizes its EVs as virulence bags that manipulate the immune system in its favour, creating a milder immune response and helping with fungal evasion from the immune system.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10962619/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140176761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of miR-29a as a novel biomarker for lumpy skin disease virus exposure in cattle.","authors":"Ram Kumar, Himanshu Kamboj, Shweta Dhanda, Assim Verma, Yogesh Chander, Kuldeep Nehra, Adrish Bhati, Ramesh Kumar Dedar, Deepak Kumar Sharma, Sanjay Barua, Bhupendra N Tripathi, Shalini Sharma, Naveen Kumar","doi":"10.1080/21505594.2024.2324711","DOIUrl":"10.1080/21505594.2024.2324711","url":null,"abstract":"<p><p>Micro RNAs (miRNAs) have been implicated in the regulation of maturation, proliferation, differentiation, and activation of immune cells. In this study, we demonstrated that miR-29a antagonizes IFN-γ production at early times post-LSDV infection in cattle. miR-29a was predicted to target upstream IFN-γ regulators, and its inhibition resulted in enhanced IFN-γ production in sensitized peripheral blood mononuclear cells (PBMCs). Further, stimulation of PBMCs with LSDV antigen exhibited lower levels of miR-29a, concomitant with a potent cell-mediated immune response (CMI), characterized by an increase in LSDV-specific CD8+ T cell counts and enhanced levels of IFN-γ, which eventually facilitated virus clearance. In addition, a few immunocompromised cattle (developed secondary LSDV infection at ~ 6 months) that failed to mount a potent cell-mediated immune response, were shown to maintain higher miR-29a levels. Furthermore, as compared to the sensitized crossbred cattle, PBMCs from sensitized Rathi (a native Indian breed) animals exhibited lower levels of miR-29a along with an increase in CD8+ T cell counts and enhanced levels of IFN-γ. Finally, we analysed that a ≥ 60% decrease in miR-29a expression levels in the PBMCs of sensitized cattle correlated with a potent CMI response. In conclusion, miR-29a expression is involved in antagonizing the IFN-γ response in LSDV-infected cattle and may serve as a novel biomarker for the acute phase of LSDV infection, as well as predicting the functionality of T cells in sensitized cattle. In addition, Rathi cattle mount a more potent CMI response against LSDV than crossbred cattle.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10965105/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140289063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A c-di-GMP binding effector STM0435 modulates flagellar motility and pathogenicity in <i>Salmonella</i>.","authors":"Yuanji Dai, Ruirui Liu, Yingying Yue, Nannan Song, Haihong Jia, Zhongrui Ma, Xueyan Gao, Min Zhang, Xilu Yuan, Qing Liu, Xiaoyu Liu, Bingqing Li, Weiwei Wang","doi":"10.1080/21505594.2024.2331265","DOIUrl":"10.1080/21505594.2024.2331265","url":null,"abstract":"<p><p>Flagella play a crucial role in the invasion process of <i>Salmonella</i> and function as a significant antigen that triggers host pyroptosis. Regulation of flagellar biogenesis is essential for both pathogenicity and immune escape of <i>Salmonella</i>. We identified the conserved and unknown function protein STM0435 as a new flagellar regulator. The ∆<i>stm0435</i> strain exhibited higher pathogenicity in both cellular and animal infection experiments than the wild-type <i>Salmonella</i>. Proteomic and transcriptomic analyses demonstrated dramatic increases in almost all flagellar genes in the ∆<i>stm0435</i> strain compared to wild-type <i>Salmonella</i>. In a surface plasmon resonance assay, purified STM0435 protein-bound c-di-GMP had an affinity of ~8.383 µM. The crystal structures of apo-STM0435 and STM0435&c-di-GMP complex were determined. Structural analysis revealed that R33, R137, and D138 of STM0435 were essential for c-di-GMP binding. A <i>Salmonella</i> with STM1987 (GGDEF protein) or STM4264 (EAL protein) overexpression exhibits completely different motility behaviours, indicating that the binding of c-di-GMP to STM0435 promotes its inhibitory effect on <i>Salmonella</i> flagellar biogenesis.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10978029/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140294683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic, virulence, and antimicrobial resistance characteristics associated with distinct morphotypes in ST11 carbapenem-resistant <i>Klebsiella pneumoniae</i>.","authors":"Tao Chen, Yuan Wang, Xiaohui Chi, Luying Xiong, Ping Lu, Xueting Wang, Yunbo Chen, Qixia Luo, Ping Shen, Yonghong Xiao","doi":"10.1080/21505594.2024.2349768","DOIUrl":"10.1080/21505594.2024.2349768","url":null,"abstract":"<p><p>ST11 is the most common lineage among carbapenem-resistant <i>Klebsiella pneumoniae</i> (CRKP) infections in Asia. Diverse morphotypes resulting from genetic mutations are associated with significant differences in microbial characteristics among <i>K. pneumoniae</i> isolates. Here, we investigated the genetic determinants and critical characteristics associated with distinct morphotypes of ST11 CRKP. An ST11-KL47 CRKP isolate carrying a pLVPK-like virulence plasmid was isolated from a patient with a bloodstream infection; the isolate had the \"mcsw\" morphotype. Two distinct morphotypes (\"ntrd\" and \"msdw\") were derived from this strain during <i>in vitro</i> passage. Whole genome sequencing was used to identify mutations that cause the distinct morphotypes of ST11 CRKP. Transmission electron microscopy, antimicrobial susceptibility tests, growth assays, biofilm formation, virulence assays, membrane permeability assays, and RNA-seq analysis were used to investigate the specific characteristics associated with different morphotypes of ST11 CRKP. Compared with the parental mcsw morphotype, the ntrd morphotype resulted from mutation of genes involved in capsular polysaccharide biosynthesis (<i>wza</i>, <i>wzc</i>, and <i>wbaP</i>), a result validated by gene knockout experiments. This morphotype showed capsule deficiency and lower virulence potential, but higher biofilm production. By contrast, the msdw morphotype displayed competition deficiency and increased susceptibility to chlorhexidine and polymyxin B. Further analyses indicated that these characteristics were caused by interruption of the sigma factor gene <i>rpoN</i> by insertion mutations and deletion of the <i>rpoN</i> gene, which attenuated membrane integrity presumably by downregulating the phage shock protein operon. These data expand current understanding of genetic, virulence, and antimicrobial resistance characteristics associated with distinct morphotypes in ST11 CRKP.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11093053/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140912812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of Norovirus capsid protein-specific CD8⁺ T-Cell responses in previously infected individuals.","authors":"Taojun He, Yilin Deng, Fang Zhang, Jin Zhang, Luhong Zhu, Qinjin Wang, Jie Ning, Hui Wu, Hanmei Yuan, Bin Li, Chao Wu","doi":"10.1080/21505594.2024.2360133","DOIUrl":"10.1080/21505594.2024.2360133","url":null,"abstract":"<p><p>Norovirus (NV) infection causes acute gastroenteritis in children and adults. Upon infection with NV, specific CD8⁺ T cells, which play an important role in anti-infective immunity, are activated in the host. Owing to the NV's wide genotypic variability, it is challenging to develop vaccines with cross-protective abilities against infection. To aid effective vaccine development, we examined specific CD8⁺ T-cell responses towards viral-structural protein (VP) epitopes, which enable binding to host susceptibility receptors. We isolated peripheral blood mononuclear cells from 196 participants to screen and identify predominant core peptides towards NV main and small envelope proteins using <i>ex vivo</i> and <i>in vitro</i> intracellular cytokine staining assays. Human leukocyte antigen (HLA) restriction characteristics were detected using next-generation sequencing. Three conservative immunodominant VP-derived CD8⁺ T-cell epitopes, VP2_94-102 (TDAARGAIN), VP2_153-161 (RGPSNKSSN), and VP1_141-148 (FPHIIVDV), were identified and restrictively presented by HLA-Cw * 0102, HLA-Cw * 0702, and HLA-A *1101 alleles, separately. Our findings provide useful insights into the development of future vaccines and treatments for NV infection.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11141469/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141158787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measles virus: Continued outbreaks while striving for eradication.","authors":"David Jesse Sanchez","doi":"10.1080/21505594.2024.2386022","DOIUrl":"10.1080/21505594.2024.2386022","url":null,"abstract":"","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11299623/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141876085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling host-pathogen dynamics in a murine Model of septic peritonitis induced by vancomycin-resistant <i>Enterococcus faecium</i>.","authors":"Xin Yuan, Xiaolin Song, Xi Zhang, Lingfei Hu, Dongsheng Zhou, Jianlong Zhang, Chenxi Dai","doi":"10.1080/21505594.2024.2367659","DOIUrl":"10.1080/21505594.2024.2367659","url":null,"abstract":"<p><p>Vancomycin-resistant <i>Enterococcus faecium</i> (<i>E. faecium</i>) infection is associated with higher mortality rates. Previous studies have emphasized the importance of innate immune cells and signalling pathways in clearing <i>E. faecium</i>, but a comprehensive analysis of host-pathogen interactions is lacking. Here, we investigated the interplay of host and <i>E. faecium</i> in a murine model of septic peritonitis. Following injection with a sublethal dose, we observed significantly increased murine sepsis score and histological score, decreased weight and bacterial burden, neutrophils and macrophages infiltration, and comprehensive activation of cytokine-mediated signalling pathway. In mice receiving a lethal dose, hypothermia significantly improved survival, reduced bacterial burden, cytokines, and CD86 expression of MHC-II⁺ recruited macrophages compared to the normothermia group. A mathematical model constructed by observational data from 80 animals, recapitulated the host-pathogen interplay, and further verified the benefits of hypothermia. These findings indicate that <i>E. faecium</i> triggers a severe activation of cytokine-mediated signalling pathway, and hypothermia can improve outcomes by reducing bacterial burden and inflammation.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11221476/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141477526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SsCyp86 modulates <i>sporisorium scitamineum</i> mating/filamentation and pathogenicity through regulating fatty acid metabolism.","authors":"Enping Cai, Jiaru Deng, Ruqing Feng, Wenqiang Zheng, Yifang Wang, Meixin Yan, Changqing Chang","doi":"10.1080/21505594.2024.2395833","DOIUrl":"10.1080/21505594.2024.2395833","url":null,"abstract":"<p><strong>Background: </strong>Fatty acid metabolism constitutes a significant and intricate biochemical process within microorganisms. Cytochrome P450 (CYP450) enzymes are found in most organisms and occupy a pivotal position in the metabolism of fatty acids. However, the role of CYP450 enzyme mediated fatty acid metabolism in the pathogenicity of pathogenic fungi remains unclear.</p><p><strong>Methods: </strong>In this study, a CYP450 enzyme-encoding gene, <i>SsCYP86</i>, was identified in the sugarcane smut fungus <i>Sporisorium scitamineum</i> and its functions were characterized using a target gene homologous recombination strategy and metabonomics.</p><p><strong>Results: </strong>We found that the expression of <i>SsCYP86</i> was induced by or sugarcane wax or under the condition of mating/filamentation. Sexual reproduction assay demonstrated that the <i>SsCYP86</i> deletion mutant was defective in mating/filamentation and significantly reduced its pathogenicity. Further fatty acid metabolomic analysis unravelled the levels of fatty acid metabolites were reduced in the <i>SsCYP86</i> deletion mutant. Exogenous addition of fatty acid metabolites cis-11-eicosenoic acid (C20:1N9), pentadecanoic acid (C15:0), and linolenic acid (C18:3N3) partially restored the mating/filamentation ability of the <i>SsCYP86</i> deletion mutant and restored the transcriptional level of the <i>SsPRF1</i>, a pheromone response transcription factor that is typically down-regulated in the absence of <i>SsCYP86</i>. Moreover, the constitutive expression of <i>SsPRF1</i> in the <i>SsCYP86</i> deletion mutant restored its mating/filamentation.</p><p><strong>Conclusion: </strong>Our results indicated that SsCyp86 modulates the <i>SsPRF1</i> transcription by fatty acid metabolism, and thereby regulate the sexual reproduction of <i>S. scitamineum</i>. These findings provide insights into how CYPs regulate sexual reproduction in <i>S. scitamineum</i>.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11352786/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142037075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insect hypovirulence-associated mycovirus confers entomopathogenic fungi with enhanced resistance against phytopathogens.","authors":"Li Sui,Yang Lu,Mengnan Xu,Jianfeng Liu,Yu Zhao,Qiyun Li,Zhengkun Zhang","doi":"10.1080/21505594.2024.2401978","DOIUrl":"https://doi.org/10.1080/21505594.2024.2401978","url":null,"abstract":"Mycoviruses can alter the biological characteristics of host fungi, including change virulence or pathogenicity of phytopathogens and entomopathogenic fungi (EPF). However, most studies on the mycoviruses found in EPF have focused on the effects of the viruses on the virulence of host fungi towards insect pests, with relatively few reports on the effects to the host fungi with regard to plant disease resistance in hosts. The present study investigated the effects of the mycovirus Beauveria bassiana chrysovirus 2 (BbCV2) virus infection on host biological characteristics, evaluated antagonistic activity of BbCV2 against two phytopathogenic fungi (Sclerotinia sclerotiorum and Botrytis cinerea), and transcriptome analysis was used to reveal the interactions between viruses and hosts. Our results showed that BbCV2 virus infection increased B. bassiana's growth rate, spore production, and biomass, it also enhanced the capacity of host fungi and their metabolic products to inhibit phytopathogenic fungi. BbCV2 virus infection reduced the contents of the two pathogens in tomato plants significantly, and transcriptome analysis revealed that the genes related to competition for ecological niches and nutrition, mycoparasitism and secondary metabolites in B. bassiana were significantly up-regulated after viral infection. These findings indicated that the mycovirus infection is an important factor to enhance the ability of B. bassiana against plant disease after endophytic colonization. We suggest that mycovirus infection causes a positive effect on B. bassiana against phytopathogens, which should be considered as a potential strategy to promote the plant disease resistance of EPF.","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.2,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Host-adaptive mutations in Chikungunya virus genome.","authors":"Xinhang Ning,Binghui Xia,Jiaqi Wang,Rong Gao,Hao Ren","doi":"10.1080/21505594.2024.2401985","DOIUrl":"https://doi.org/10.1080/21505594.2024.2401985","url":null,"abstract":"Chikungunya virus (CHIKV) is the causative agent of chikungunya fever (CHIKF), and its primary vectors are the mosquitoes Aedes aegypti and Aedes albopictus. CHIKV was initially endemic to Africa but has spread globally in recent years and affected millions of people. According to a risk assessment by the World Health Organization, CHIKV has the potential seriously impact public health. A growing body of research suggests that mutations in the CHIKV gene that enhance viral fitness in the host are contributing to the expansion of the global CHIKF epidemic. In this article, we review the host-adapted gene mutations in CHIKV under natural evolution and laboratory transmission conditions, which can help improve our understanding of the adaptive evolution of CHIKV and provide a basis for monitoring and early warning of future CHIKV outbreaks.","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.2,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}