PLoS PathogensPub Date : 2025-01-08eCollection Date: 2025-01-01DOI: 10.1371/journal.ppat.1012823
Kelly T Rios, James P McGee, Aswathy Sebastian, Sanjaya Aththawala Gedara, Robert L Moritz, Marina Feric, Sabrina Absalon, Kristian E Swearingen, Scott E Lindner
{"title":"Widespread release of translational repression across Plasmodium's host-to-vector transmission event.","authors":"Kelly T Rios, James P McGee, Aswathy Sebastian, Sanjaya Aththawala Gedara, Robert L Moritz, Marina Feric, Sabrina Absalon, Kristian E Swearingen, Scott E Lindner","doi":"10.1371/journal.ppat.1012823","DOIUrl":"10.1371/journal.ppat.1012823","url":null,"abstract":"<p><p>Malaria parasites must respond quickly to environmental changes, including during their transmission between mammalian and mosquito hosts. Therefore, female gametocytes proactively produce and translationally repress mRNAs that encode essential proteins that the zygote requires to establish a new infection. While the release of translational repression of individual mRNAs has been documented, the details of the global release of translational repression have not. Moreover, changes in the spatial arrangement and composition of the DOZI/CITH/ALBA complex that contribute to translational control are also not known. Therefore, we have conducted the first quantitative, comparative transcriptomics and DIA-MS proteomics of Plasmodium parasites across the host-to-vector transmission event to document the global release of translational repression. Using female gametocytes and zygotes of P. yoelii, we found that ~200 transcripts are released for translation soon after fertilization, including those encoding essential functions. Moreover, we identified that many transcripts remain repressed beyond this point. TurboID-based proximity proteomics of the DOZI/CITH/ALBA regulatory complex revealed substantial spatial and/or compositional changes across this transmission event, which are consistent with recent, paradigm-shifting models of translational control. Together, these data provide a model for the essential translational control mechanisms that promote Plasmodium's efficient transmission from mammalian host to mosquito vector.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"21 1","pages":"e1012823"},"PeriodicalIF":5.5,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11750109/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142957264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
PLoS PathogensPub Date : 2025-01-07eCollection Date: 2025-01-01DOI: 10.1371/journal.ppat.1012844
Byung-Hak Song, Sang-Im Yun, Joseph L Goldhardt, Jiyoun Kim, Young-Min Lee
{"title":"Key virulence factors responsible for differences in pathogenicity between clinically proven live-attenuated Japanese encephalitis vaccine SA14-14-2 and its pre-attenuated highly virulent parent SA14.","authors":"Byung-Hak Song, Sang-Im Yun, Joseph L Goldhardt, Jiyoun Kim, Young-Min Lee","doi":"10.1371/journal.ppat.1012844","DOIUrl":"10.1371/journal.ppat.1012844","url":null,"abstract":"<p><p>Japanese encephalitis virus (JEV), a neuroinvasive and neurovirulent orthoflavivirus, can be prevented in humans with the SA14-14-2 vaccine, a live-attenuated version derived from the wild-type SA14 strain. To determine the viral factors responsible for the differences in pathogenicity between SA14 and SA14-14-2, we initially established a reverse genetics system that includes a pair of full-length infectious cDNAs for both strains. Using this cDNA pair, we then systematically exchanged genomic regions between SA14 and SA14-14-2 to generate 20 chimeric viruses and evaluated their replication capability in cell culture and their pathogenic potential in mice. Our findings revealed the following: (i) The single envelope (E) protein of SA14-14-2, which contains nine mutations (eight in the ectodomain and one in the stem region), is both necessary and sufficient to render SA14 non-neuroinvasive and non-neurovirulent. (ii) Conversely, the E protein of SA14 alone is necessary for SA14-14-2 to become highly neurovirulent, but it is not sufficient to make it highly neuroinvasive. (iii) The limited neuroinvasiveness of an SA14-14-2 derivative that contains the E gene of SA14 significantly increases (approaching that of the wild-type strain) when two viral nonstructural proteins are replaced by their counterparts from SA14: (a) NS1/1', which has four mutations on the external surface of the core β-ladder domain; and (b) NS2A, which has two mutations in the N-terminal region, including two non-transmembrane α-helices. In line with their roles in viral pathogenicity, the E, NS1/1', and NS2A genes all contribute to the enhanced spread of the virus in cell culture. Collectively, our data reveal for the first time that the E protein of JEV has a dual function: It is the master regulator of viral neurovirulence and also the primary initiator of viral neuroinvasion. After the initial E-mediated neuroinvasion, the NS1/1' and NS2A proteins act as secondary promoters, further amplifying viral neuroinvasiveness.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"21 1","pages":"e1012844"},"PeriodicalIF":5.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11741592/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142957349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Microsporidian Nosema bombycis secretes serine protease inhibitor to suppress host cell apoptosis via Caspase BmICE.","authors":"Maoshuang Ran, Jialing Bao, Boning Li, Yulian Shi, Wenxin Yang, Xianzhi Meng, Jie Chen, Junhong Wei, Mengxian Long, Tian Li, Chunfeng Li, Guoqing Pan, Zeyang Zhou","doi":"10.1371/journal.ppat.1012373","DOIUrl":"10.1371/journal.ppat.1012373","url":null,"abstract":"<p><p>Microsporidia are a group of intracellular pathogens that actively manipulate host cell biological processes to facilitate their intracellular niche. Apoptosis is an important defense mechanism by which host cell control intracellular pathogens. Microsporidia modulating host cell apoptosis has been reported previously, however the molecular mechanism is not yet clear. In this report, we describe that the microsporidia Nosema bombycis inhibits apoptosis of Bombyx mori cells through a secreted protein NbSPN14, which is a serine protease inhibitor (Serpin). An immunofluorescent assay demonstrated that upon infection with N. bombycis, NbSPN14 was initially found in the B. mori cell cytoplasm and then became enriched in the host cell nucleus. Overexpression and RNA-interference (RNAi) of NbSPN14 in B. mori' embryo cell confirmed that NbSPN14 inhibited host cells apoptosis. Immunofluorescent and Co-IP assays verified the co-localization and interaction of NbSPN14 with the BmICE, the Caspase 3 homolog in B. mori. Knocking out of BmICE or mutating the BmICE-interacting P1 site of NbSPN14, eliminated the localization of NbSPN14 into the host nucleus and prevented the apoptosis-inhibiting effect of NbSPN14, which also proved that the interaction between BmICE and NbSPN14 occurred in host cytoplasm and the NbSPN14 translocation into host cell nucleus depends on BmICE. These data elucidate that N. bombycis secretory protein NbSPN14 inhibits host cell apoptosis by directly inhibiting the Caspase protease BmICE, which provides an important insight for understanding pathogen-host interactions and a potential therapeutic target for N. bombycis proliferation.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"21 1","pages":"e1012373"},"PeriodicalIF":5.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11741654/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142957351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cross-species recognition of two porcine coronaviruses to their cellular receptor aminopeptidase N of dogs and seven other species.","authors":"Yuyang Tian, Junqing Sun, Xiaohan Hou, Zhimin Liu, Zeao Chen, Xiaoqian Pan, Ying Wang, Jianle Ren, Ding Zhang, Bo Yang, Longlong Si, Yuhai Bi, Kefang Liu, Guijun Shang, Wen-Xia Tian, Qihui Wang, George Fu Gao, Sheng Niu","doi":"10.1371/journal.ppat.1012836","DOIUrl":"10.1371/journal.ppat.1012836","url":null,"abstract":"<p><p>Porcine deltacoronavirus (PDCoV) and transmissible gastroenteritis coronavirus (TGEV), the two causative agents of porcine diarrhea, have been reported to be at risk of cross-species transmission, including to humans. However, the potential host range in which these two CoVs interact remains unclear. We screened 16 animal counterparts for porcine aminopeptidase N (APN), the receptor of PDCoV and TGEV, and found that APNs from eight of 17 animals could bind to the receptor-binding domains (RBDs) of PDCoV and TGEV. Furthermore, the animal APNs that could bind to the RBDs could mediate cellular infection by both viruses. Dog APN (dAPN) has been identified as the animal receptor with the highest capability to mediate the virus infection. We further resolved the complex structures of dAPN bound to the PDCoV RBD/TGEV RBD, respectively, establishing its divergent receptor-binding modes. We identified R325 of dAPN as an important residue in the PDCoV RBD-dAPN interaction, and found the central role of Q746 and T749 in dAPN in the interaction with the TGEV RBD. These findings provide the molecular basis of the potential cross-species transmission of these two porcine CoVs and shed light on future surveillance of these CoVs.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"21 1","pages":"e1012836"},"PeriodicalIF":5.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11741606/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142957331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
PLoS PathogensPub Date : 2025-01-07eCollection Date: 2025-01-01DOI: 10.1371/journal.ppat.1012804
Stefanos Giannakopoulos, Jin Pak, Jackson Bakse, Monika A Ward, Vivek R Nerurkar, Michelle D Tallquist, Saguna Verma
{"title":"SARS-CoV-2-induced cytokine storm drives prolonged testicular injury and functional impairment in mice that are mitigated by dexamethasone.","authors":"Stefanos Giannakopoulos, Jin Pak, Jackson Bakse, Monika A Ward, Vivek R Nerurkar, Michelle D Tallquist, Saguna Verma","doi":"10.1371/journal.ppat.1012804","DOIUrl":"10.1371/journal.ppat.1012804","url":null,"abstract":"<p><p>Compromised male reproductive health, including reduced testosterone and sperm count, is one of the long COVID symptoms in individuals recovering from mild-severe disease. COVID-19 patients display testicular injury in the acute stage and altered serum fertility markers in the recovery phase, however, long-term implications on the testis remain unknown. This study characterized the consequences of SARS-CoV-2 on testis function. The K18-hACE2 mice that survived SARS-CoV-2 infection were followed for one month after infection and the testicular injury and function markers were assessed at different stages of infection and recovery. The long-term impact of infection on key testes function-related hormones and male fertility was measured. The efficacy of inflammation-suppressing drug in preventing testicular injury was also evaluated. The morphological defects like sloughing of spermatids into the lumen and increased apoptotic cells sustained for 2-4 weeks after infection and correlated with testicular inflammation and immune cell infiltration. Transcriptomic analysis revealed dysregulation of inflammatory, cell death, and steroidogenic pathways. Furthermore, reduced testosterone levels associated with a transient reduction in sperm count and male fertility. Most testicular impairments resolved within one month of infection. Importantly, dexamethasone treatment attenuated testicular damage, inflammation, and immune infiltration. Our results implicate virus-induced cytokine storm as the major driver of testicular injury and functional impairments, timely prevention of which limits testis damage. These findings serve as a model for evaluating therapeutics in long COVID patients and may guide clinical strategies to improve male reproductive health outcomes post-SARS-CoV-2 infection.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"21 1","pages":"e1012804"},"PeriodicalIF":5.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11706467/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142957262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
PLoS PathogensPub Date : 2025-01-07eCollection Date: 2025-01-01DOI: 10.1371/journal.ppat.1012799
Lukas Kunz, Jigisha Jigisha, Fabrizio Menardo, Alexandros G Sotiropoulos, Helen Zbinden, Shenghao Zou, Dingzhong Tang, Ralph Hückelhoven, Beat Keller, Marion C Müller
{"title":"Avirulence depletion assay: Combining R gene-mediated selection with bulk sequencing for rapid avirulence gene identification in wheat powdery mildew.","authors":"Lukas Kunz, Jigisha Jigisha, Fabrizio Menardo, Alexandros G Sotiropoulos, Helen Zbinden, Shenghao Zou, Dingzhong Tang, Ralph Hückelhoven, Beat Keller, Marion C Müller","doi":"10.1371/journal.ppat.1012799","DOIUrl":"10.1371/journal.ppat.1012799","url":null,"abstract":"<p><p>Wheat production is threatened by multiple fungal pathogens, such as the wheat powdery mildew fungus (Blumeria graminis f. sp. tritici, Bgt). Wheat resistance breeding frequently relies on the use of resistance (R) genes that encode diverse immune receptors which detect specific avirulence (AVR) effectors and subsequently induce an immune response. While R gene cloning has accelerated recently, AVR identification in many pathogens including Bgt lags behind, preventing pathogen-informed deployment of resistance sources. Here we describe a new \"avirulence depletion (AD) assay\" for rapid identification of AVR genes in Bgt. This assay relies on the selection of a segregating, haploid F1 progeny population on a resistant host, followed by bulk sequencing, thereby allowing rapid avirulence candidate gene identification with high mapping resolution. In a proof-of-concept experiment we mapped the AVR component of the wheat immune receptor Pm3a to a 25 kb genomic interval in Bgt harboring a single effector, the previously described AvrPm3a2/f2. Subsequently, we applied the AD assay to map the unknown AVR effector recognized by the Pm60 immune receptor. We show that AvrPm60 is encoded by three tandemly arrayed, nearly identical effector genes that trigger an immune response upon co-expression with Pm60 and its alleles Pm60a and Pm60b. We furthermore provide evidence that Pm60 outperforms Pm60a and Pm60b through more efficient recognition of AvrPm60 effectors, suggesting it should be prioritized for wheat breeding. Finally, we show that virulence towards Pm60 is caused by simultaneous deletion of all AvrPm60 gene paralogs and that isolates lacking AvrPm60 are especially prevalent in the US thereby limiting the potential of Pm60 in this region. The AD assay is a powerful new tool for rapid and inexpensive AVR identification in Bgt with the potential to contribute to pathogen-informed breeding decisions for the use of novel R genes and regionally tailored gene deployment.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"21 1","pages":"e1012799"},"PeriodicalIF":5.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11741615/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142957329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"USP5 inhibits anti-RNA viral innate immunity by deconjugating K48-linked unanchored and K63-linked anchored ubiquitin on IRF3.","authors":"Zigang Qiao, Dapei Li, Fan Zhang, Jingfei Zhu, Siying Liu, Xue Bai, Haiping Yao, Zhengrong Chen, Yongdong Yan, Xiulong Xu, Feng Ma","doi":"10.1371/journal.ppat.1012843","DOIUrl":"https://doi.org/10.1371/journal.ppat.1012843","url":null,"abstract":"<p><p>Interferon regulatory factor 3 (IRF3) is a central hub transcription factor that controls host antiviral innate immunity. The expression and function of IRF3 are tightly regulated by the post-translational modifications. However, it is unknown whether unanchored ubiquitination and deubiquitination of IRF3 involve modulating antiviral innate immunity against RNA viruses. Here, we find that USP5, a deubiquitinase (DUB) regulating unanchored polyubiquitin, is downregulated during host anti-RNA viral innate immunity in a type I interferon (IFN-I) receptor (IFNAR)-dependent manner. USP5 is further identified to inhibit IRF3-triggered antiviral immune responses through its DUB enzyme activity. K48-linked unanchored ubiquitin promotes IRF3-driven transcription of IFN-β and induction of IFN-stimulated genes (ISGs) in a dose-dependent manner. USP5 simultaneously removes both K48-linked unanchored and K63-linked anchored polyubiquitin chains on IRF3. Our study not only provides evidence that unanchored ubiquitin regulates anti-RNA viral innate immunity but also proposes a novel mechanism for DUB-controlled IRF3 activation, suggesting that USP5 is a potential target for the treatment of RNA viral infectious diseases.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"21 1","pages":"e1012843"},"PeriodicalIF":5.5,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11737852/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143014551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
PLoS PathogensPub Date : 2025-01-06eCollection Date: 2025-01-01DOI: 10.1371/journal.ppat.1012787
Tingting Wang, Huaizhi Yang, Qiushuang Sheng, Ying Ding, Jian Zhang, Feng Chen, Jianfeng Wang, Lei Song, Xuming Deng
{"title":"Isoferulic acid facilitates effective clearance of hypervirulent Klebsiella pneumoniae through targeting capsule.","authors":"Tingting Wang, Huaizhi Yang, Qiushuang Sheng, Ying Ding, Jian Zhang, Feng Chen, Jianfeng Wang, Lei Song, Xuming Deng","doi":"10.1371/journal.ppat.1012787","DOIUrl":"https://doi.org/10.1371/journal.ppat.1012787","url":null,"abstract":"<p><p>Hypervirulent Klebsiella pneumoniae (hvKP) poses an alarming threat in clinical settings and global public health owing to its high pathogenicity, epidemic success and rapid development of drug resistance, especially the emergence of carbapenem-resistant lineages (CR-hvKP). With the decline of the \"last resort\" antibiotic class and the decreasing efficacy of first-line antibiotics, innovative alternative therapeutics are urgently needed. Capsule, an essential virulence determinant, is a major cause of the enhanced pathogenicity of hvKP and thus represents an attractive drug target to prevent the devastating clinical outcomes caused by hvKP infection. Here, we identified isoferulic acid (IFA), a natural phenolic acid compound widely present in traditional herbal medicines, as a potent broad-spectrum K. pneumoniae capsule inhibitor that suppresses capsule polysaccharide synthesis by increasing the energy status of bacteria. In this way, IFA remarkably reduced capsule thickness and impaired hypercapsule-associated hypermucoviscosity phenotype (HMV), thereby significantly sensitizing hvKP to complement-mediated bacterial killing and accelerating host cell adhesion and phagocytosis. Consequently, IFA facilitated effective bacterial clearance and thus remarkably protected mice from lethal hvKP infection, as evidenced by limited bacterial dissemination and a significant improvement in survival rate. In conclusion, this work promotes the development of a capsule-targeted alternative therapeutic strategy for the use of the promising candidate IFA as an intervention to curb hvKP infection, particularly drug-resistant cases.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"21 1","pages":"e1012787"},"PeriodicalIF":5.5,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11737856/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143014635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hepatitis B virus hijacks MRE11-RAD50-NBS1 complex to form its minichromosome.","authors":"Kaitao Zhao, Jingjing Wang, Zichen Wang, Mengfei Wang, Chen Li, Zaichao Xu, Qiong Zhan, Fangteng Guo, Xiaoming Cheng, Yuchen Xia","doi":"10.1371/journal.ppat.1012824","DOIUrl":"10.1371/journal.ppat.1012824","url":null,"abstract":"<p><p>Chronic hepatitis B virus (HBV) infection can significantly increase the incidence of cirrhosis and liver cancer, and there is no curative treatment. The persistence of HBV covalently closed circular DNA (cccDNA) is the major obstacle of antiviral treatments. cccDNA is formed through repairing viral partially double-stranded relaxed circular DNA (rcDNA) by varies host factors. However, the detailed mechanisms are not well characterized. To dissect the biogenesis of cccDNA, we took advantage of an in vitro rcDNA repair system to precipitate host factors interacting with rcDNA and identified co-precipitated proteins by mass spectrometry. Results revealed the MRE11-RAD50-NBS1 (MRN) complex as a potential factor. Transiently or stably knockdown of MRE11, RAD50 or NBS1 in hepatocytes before HBV infection significantly decreased viral markers, including cccDNA, while reconstitution reversed the effect. Chromatin immunoprecipitation assay further validated the interaction of MRN complex and HBV DNA. However, MRN knockdown after HBV infection showed no effect on viral replication, which indicated that MRN complex inhibited the formation of cccDNA without affecting its stability or transcriptional activity. Interestingly, Mirin, a MRN complex inhibitor which can inhibit the exonuclease activity of MRE11 and MRN-dependent activation of ATM, but not ATM kinase inhibitor KU55933, could decrease cccDNA level. Likewise, the MRE11 endonuclease activity inhibitor PFM01 treatment decreased cccDNA. MRE11 nuclease assays indicated that rcDNA is a substrate of MRE11. Furthermore, the inhibition of ATR-CHK1 pathway, which is known to be involved in cccDNA formation, impaired the effect of MRN complex on cccDNA. Similarly, inhibition of MRE11 endonuclease activity mitigated the effect of ATR-CHK1 pathway on cccDNA. These findings indicate that MRN complex cooperates with ATR-CHK1 pathway to regulate the formation of HBV cccDNA. In summary, we identified host factors, specifically the MRN complex, regulating cccDNA formation during HBV infection. These findings provide insights into how HBV hijacks host enzymes to establish chronic infection and reveal new therapeutic opportunities.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"21 1","pages":"e1012824"},"PeriodicalIF":5.5,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11734937/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142928516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
PLoS PathogensPub Date : 2025-01-03eCollection Date: 2025-01-01DOI: 10.1371/journal.ppat.1012789
Wan Zhao, Qiong Li, Mengqi Sun, Lan Luo, Xiaoming Zhang, Feng Cui
{"title":"Small interfering RNAs generated from the terminal panhandle structure of negative-strand RNA virus promote viral infection.","authors":"Wan Zhao, Qiong Li, Mengqi Sun, Lan Luo, Xiaoming Zhang, Feng Cui","doi":"10.1371/journal.ppat.1012789","DOIUrl":"https://doi.org/10.1371/journal.ppat.1012789","url":null,"abstract":"<p><p>Virus-derived small interfering RNAs (vsiRNAs) have been widely recognized to play an antiviral immunity role. However, it is unclear whether vsiRNAs can also play a positive role in viral infection. Here, we characterized three highly abundant vsiRNAs mapped to the genomic termini of rice stripe virus (RSV), a negative-strand RNA virus transmitted by insect vectors. The three vsiRNAs shared 11 nucleotides due to the conservative genomic termini and were likely generated from viral terminal panhandle structure, depending on both Dicer1 and Dicer2 in insects. In addition to targeting viral RNAs in a miRNA-like manner, the three vsiRNAs coordinately downregulated the expression of DOPA decarboxylase, thereby suppressing the prophenoloxidase immune reaction in insect vectors. In vsiRNA-silenced transgenic rice, the viral titer significantly decreased, indicating that these vsiRNAs promote RSV replication in rice. This study elucidates a unique function of vsiRNAs derived from the conserved panhandle structure of negative-strand RNA viruses in enhancing viral infection.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"21 1","pages":"e1012789"},"PeriodicalIF":5.5,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11698402/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142928518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}