mBio最新文献

{"title":"Evolution of PqsE as a <i>Pseudomonas aeruginosa</i>-specific regulator of LuxR-type receptors: insights from <i>Pseudomonas</i> and <i>Burkholderia</i>.","authors":"Caleb P Mallery, Kayla A Simanek, Autumn N Pope, Jon E Paczkowski","doi":"10.1128/mbio.00646-25","DOIUrl":"https://doi.org/10.1128/mbio.00646-25","url":null,"abstract":"<p><p><i>Pseudomonas aeruginosa</i> is a Gram-negative opportunistic pathogen that poses a significant public health threat, particularly in healthcare settings. A key determinant of <i>P. aeruginosa</i> virulence is the regulated synthesis and release of extracellular products, which is controlled by a cell density-dependent signaling system known as quorum sensing (QS). <i>P. aeruginosa</i> uses a complex QS network, including two systems that rely on diffusible N-acylhomoserine lactone (AHL) signal molecules. The LuxR-type receptor RhlR is unique in that it requires not only its cognate AHL but also the accessory protein PqsE to maximally bind to promoter DNA and initiate transcription. Our group previously demonstrated that PqsE physically interacts with RhlR, enhancing its affinity for target promoters across the <i>P. aeruginosa</i> genome. Although LuxR-type receptors are widespread in Gram-negative bacteria and important for pathogenesis, PqsE orthologs are restricted to <i>Pseudomonas</i> and <i>Burkholderia</i> species. This study explored the conservation of PqsE and examined PqsE ortholog structure-function across different species. Our results show that PqsE in <i>Pseudomonas</i> retains their functional interactions with RhlR homologs, unlike PqsE orthologs in <i>Burkholderia</i> spp., which do not interact with their respective LuxR-type receptors. Additionally, we assessed the AHL preferences of different receptors and hypothesized that the PqsE-RhlR interaction evolved to stabilize the inherently unstable RhlR, preventing its degradation. Indeed, we observe higher levels of RhlR protein turnover in a strain lacking <i>pqsE</i> compared to a wild-type strain of PA14, which can be partially rescued in a strain of <i>P. aeruginosa</i> lacking the Lon protease.</p><p><strong>Importance: </strong><i>Pseudomonas aeruginosa</i>, a major pathogen for patients with cystic fibrosis and a primary constituent of healthcare-associated infections, relies on a complex quorum-sensing (QS) network to coordinate virulence factor production. Central to this system is the interaction between two proteins, PqsE and RhlR, which drive gene expression essential for pathogenesis. Our study investigates the conservation of the PqsE-RhlR interaction across related bacterial species, revealing that PqsE in <i>Pseudomonas</i> can enhance RhlR activity, while orthologs in <i>Burkholderia</i> lack this capacity. These findings offer new insights into the specificity and evolution of QS mechanisms, highlighting the PqsE-RhlR interaction as a potentially selective target for treating <i>P. aeruginosa</i> infections.</p>","PeriodicalId":18315,"journal":{"name":"mBio","volume":" ","pages":"e0064625"},"PeriodicalIF":5.1,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New dimensions in acidocalcisome research: the potential of cryo-EM to uncover novel aspects of protozoan parasite physiology.","authors":"Ingrid Augusto, Moara Lemos, Wendell Girard-Dias, José de Anchieta Oliveira Filho, Pedro G Pascutti, Wanderley de Souza, Kildare Miranda","doi":"10.1128/mbio.01662-24","DOIUrl":"https://doi.org/10.1128/mbio.01662-24","url":null,"abstract":"<p><p>Cryo-electron microscopy (cryo-EM) has revolutionized structural biology by enabling high-resolution, near-native visualization of macromolecular structures and entire cells. Its application to etiologic agents of diseases is an expanding field, particularly for those caused by viruses or unicellular eukaryotes, such as protozoan parasites and fungi. This review focuses on acidocalcisomes-ion-rich, multifunctional organelles essential for cell physiology and survival in several pathogens. The structure and function of these organelles are examined through a range of electron microscopy techniques, using <i>Trypanosoma cruzi</i> as a model. The advantages and limitations of the methods employed to study acidocalcisome morphofunctional organization-such as chemical fixation, plunge and high-pressure freezing, cryo-electron microscopy of vitrified sections (CEMOVIS), freeze-drying, freeze substitution, tomography, and microanalysis using X rays and inelastic scattered electrons-are discussed, alongside their contributions to our current understanding of acidocalcisome structure and function. Recent advances in cryo-EM and its potential to address longstanding questions and fill existing gaps in our understanding of parasite ion mobilization mechanisms and physiology are also discussed.</p>","PeriodicalId":18315,"journal":{"name":"mBio","volume":" ","pages":"e0166224"},"PeriodicalIF":5.1,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel small non-coding RNAs of Epstein-Barr virus upregulated upon lytic reactivation aid in viral genomic replication and virion production.","authors":"Sagarika Banerjee, Dipayan Bose, Steve Johnson, Jie Liu, Herbert Virgin, Erle S Robertson","doi":"10.1128/mbio.04060-24","DOIUrl":"https://doi.org/10.1128/mbio.04060-24","url":null,"abstract":"<p><p>Epstein-Barr virus (EBV) employs various strategies for long-term survival, including the expression of non-coding RNAs (ncRNAs). This study uncovers and characterizes two novel EBV-encoded ncRNAs, p7 and p8, which are upregulated during lytic reactivation and interact with both viral and host genomes. These ncRNAs bind to cellular RNA transcripts, significantly reducing ARMCX3 mRNA levels, while p8 also influences PTPN6 and RPL24 expressions. Although p7 does not directly bind to LMP1 RNA but both ncRNAs found to downregulate LMP1 expression. Furthermore, these ncRNAs interact with the OriLyt region of EBV genome, promoting viral DNA replication. Functional assays indicate that p7 and p8 enhance cell proliferation and inhibit apoptosis by modulating the p53 pathway and suppressing pro-apoptotic proteins. These findings highlight the role of p7 and p8 in supporting EBV persistence by regulating viral replication, cell survival, and immune evasion, making them promising targets for therapeutic strategies in EBV-related diseases.IMPORTANCEEpstein-Barr virus (EBV) employs diverse strategies for long-term persistence in the host, including the expression of viral non-coding RNAs (ncRNAs) that manipulate key cellular pathways to promote viral replication and immune evasion. This study identifies two novel EBV-encoded ncRNAs, p7 and p8, which are upregulated during lytic reactivation and interact with both viral and host genes to regulate viral DNA replication and promote host cellular survival. By modulating apoptotic and proliferative pathways, p7 and p8 facilitate viral reactivation while promoting host cell survival, highlighting their potential as critical regulators in EBV-driven oncogenesis. This discovery expands our understanding of EBV-host interactions, suggesting p7 and p8 as targets for novel therapeutic strategies in EBV-associated malignancies.</p>","PeriodicalId":18315,"journal":{"name":"mBio","volume":" ","pages":"e0406024"},"PeriodicalIF":5.1,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tumor-colonizing <i>Pseudoalteromonas elyakovii</i> metabolically reprograms the tumor microenvironment and promotes breast ductal carcinoma.","authors":"Shuyan Liu, Youpeng Pan, Chaopeng Zheng, Qinghui Zheng, Yaoqiang Du, Yajuan Zheng, Hongchao Tang, Xiaozhen Liu, Jiancheng Mou, Xin Zeng, Zhuotao Yang, Wenjuan Gui, Yuning Tang, Mingxing Xu, Zhihao Ye, Haotian Su, Qiuran Xu, Xuli Meng","doi":"10.1128/mbio.03873-24","DOIUrl":"https://doi.org/10.1128/mbio.03873-24","url":null,"abstract":"<p><p>The correlation between the microbiota found in tumors and tumor development is being progressively understood, specifically regarding its involvement in the initiation and advancement of tumors. We examined a total of 102 samples, examining the microbial composition at the species level in each person unveiled significant variations in both the microbial makeup and tumor proportions among individuals, examining the fluctuating alterations in the microbial profile during breast cancer advancement and progression. The levels of expression for <i>Pseudoalteromonas elyakovii</i> were notably elevated in the tumor groups when compared to the para-cancer normal group, aligning with the results obtained from qRT-PCR analysis. The relationship between tumor immunity and microorganisms within the tumor was investigated using double immunofluorescence staining combined with SweAMI probe <i>in situ</i> hybridization and scRNA-seq, allowing for an in-depth analysis of intratumoral microorganisms. Experiments have demonstrated that the supernatant derived from <i>P. elyakovii</i> displayed a significant ability to promote tumor growth and stimulation. In summary, we describe the characteristics of the intratumoral microbiota and the tumor-promoting effects of <i>P. elyakovii</i> supernatant within a small dose range in ductal carcinoma of the breast and characterize the potential clinical application value of intratumoural microorganisms in the progression of cancer and immunotherapy.</p><p><strong>Importance: </strong>Despite the existing studies, the specific microbial factors that influence the occurrence and progression of breast cancer still remain unclear. Researchers have clarified the distinctive microbial profile related to ductal carcinoma, a common histological type of breast cancer, in order to identify tumor-specific microbes and their roles in tumorigenesis. With the tumor microbiome as the focus, the enrichment of <i>Pseudoalteromonas elyakovii</i> features accelerates the disease progression in patients with ductal carcinoma of the breast. This study reveals the initial role relationship and innovative findings between <i>Pseudoalteromonas elyakovii</i> and ductal carcinoma in the breast.</p>","PeriodicalId":18315,"journal":{"name":"mBio","volume":" ","pages":"e0387324"},"PeriodicalIF":5.1,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143795750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular mechanisms of drug resistance and compensation in SARS-CoV-2 main protease: the interplay between E166 and L50.","authors":"Sarah N Zvornicanin, Ala M Shaqra, Julia Flynn, Heidi Carias Martinez, Weiping Jia, Stephanie Moquin, Dustin Dovala, Daniel N Bolon, Nese Kurt Yilmaz, Celia A Schiffer","doi":"10.1128/mbio.04068-24","DOIUrl":"https://doi.org/10.1128/mbio.04068-24","url":null,"abstract":"<p><p>The SARS-CoV-2 main protease (M^pro) is essential for viral replication and is a primary target for COVID-19 antivirals. Direct-acting antivirals such as nirmatrelvir, the active component of Paxlovid, target the M^pro active site to block viral polyprotein cleavage and thus replication. However, drug resistance mutations at the active site residue Glu166 (E166) have emerged during <i>in vitro</i> selection studies, raising concerns about the durability of current antiviral strategies. Here, we investigate the molecular basis of drug resistance conferred by E166A and E166V mutations against nirmatrelvir and the related PF-00835231, individually and in combination with the distal mutation L50F. We found that E166 mutations reduce nirmatrelvir potency by up to 3,000-fold while preserving substrate cleavage, with catalytic efficiency reduced by only up to twofold. This loss of catalytic efficiency was compensated for by the addition of L50F in the double-mutant variants. We have determined three cocrystal structures of the E166 variants (E166A, E166V, and E166V/L50F) bound to PF-00835231. Comparison of these structures with wild-type enzyme demonstrated that E166 is crucial for dimerization and for shaping the substrate-binding S1 pocket. Our findings highlight the mutability of E166, a prime site for resistance for inhibitors that leverage direct interactions with this position, and the potential emergence of highly resistant and active variants in combination with the compensatory mutation L50F. These insights support the design of inhibitors that target conserved protease features and avoid E166 side-chain interactions to minimize susceptibility to resistance.</p><p><strong>Importance: </strong>Drug resistance remains a great challenge to modern medicine. This study investigates SARS-CoV-2 main protease variants E166A and E166V which confer nirmatrelvir resistance. These variants can retain considerable enzymatic activity through combination with the compensatory mutation L50F. For single- and double-mutant variant enzymes, we assessed catalytic efficiency, measured loss in potency for nirmatrelvir and its analog PF-00835231, and cocrystallized with inhibitors to investigate drug resistance caused by these mutations. Our results contribute toward understanding of molecular mechanisms of resistance and combinations of mutations, which pushes toward resistance-thwarting inhibitor design. These principles also apply broadly to many quickly evolving drug targets in infectious diseases.</p>","PeriodicalId":18315,"journal":{"name":"mBio","volume":" ","pages":"e0406824"},"PeriodicalIF":5.1,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143780139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial solutions for climate change require global partnership.","authors":"J T Lennon, R Rappuoli, D E Bloom, C Brooke, R M Burckhardt, A D Dangour, D Egamberdieva, G K Gronvall, T D Lawley, R Morhard, A Mukhopadhyay, R S Peixoto, P A Silver, V Sperandio, L Y Stein, N K Nguyen","doi":"10.1128/mbio.00778-25","DOIUrl":"https://doi.org/10.1128/mbio.00778-25","url":null,"abstract":"","PeriodicalId":18315,"journal":{"name":"mBio","volume":" ","pages":"e0077825"},"PeriodicalIF":5.1,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual-use virulence factors of the opportunistic pathogen <i>Chromobacterium haemolyticum</i> mediate hemolysis and colonization.","authors":"Leo Dumjahn, Philipp Wein, Evelyn M Molloy, Kirstin Scherlach, Felix Trottmann, Philippe R Meisinger, Louise M Judd, Sacha J Pidot, Timothy P Stinear, Ingrid Richter, Christian Hertweck","doi":"10.1128/mbio.03605-24","DOIUrl":"https://doi.org/10.1128/mbio.03605-24","url":null,"abstract":"<p><p><i>Chromobacterium haemolyticum</i> is an environmental bacterium that can cause severe and fatal opportunistic infections in humans and animals. Although <i>C. haemolyticum</i> is characterized by its strong β-hemolytic activity, the molecular basis of this phenotype has remained elusive over the more than 15 years since the species was first described. Herein, we report a family of cyclic lipodepsipeptides, the jagaricins, that are responsible for the potent hemolytic activity of <i>C. haemolyticum</i>. Comparative genomics of <i>C. haemolyticum</i> strains revealed a completely conserved gene locus (<i>hml</i>) encoding a nonribosomal peptide synthetase. Metabolic profiling of <i>C. haemolyticum</i> DSM 19808 identified a suite of cyclic lipodepsipeptides as the products, with the three main congeners (jagaricin A-C) being elucidated by a combination of tandem mass spectrometry, chemical derivatization, and nuclear magnetic resonance spectroscopy. Significantly, a <i>C. haemolyticum hml</i> deletion mutant is devoid of hemolytic activity. Moreover, purified jagaricins are hemolytic at low micromolar concentrations in an erythrocyte lysis assay. Further bioassays demonstrated that the cyclic lipodepsipeptides are crucial for the biofilm-forming and swarming behavior of <i>C. haemolyticum</i>. Matrix-assisted laser desorption ionization mass spectrometry imaging showed that primarily jagaricin B and C are involved in these processes <i>in vitro</i>. Our data shed light on the bioactivities of jagaricins, specialized metabolites that likely contribute to both successful niche colonization and the virulence potential of <i>C. haemolyticum</i>.IMPORTANCEDespite the rising incidence of <i>Chromobacterium haemolyticum</i> as a serious opportunistic pathogen, there is limited information on whether the competitive traits that ensure its survival in its freshwater niche also influence host infection. We reveal that <i>C. haemolyticum</i> produces specialized metabolites that not only cause its pronounced hemolytic phenotype but are also crucial for biofilm formation and swarming motility. These results exemplify a case of coincidental evolution, wherein the selective pressures encountered in a primary environmental niche drive the evolution of a trait impacting virulence. This knowledge provides a foundation for the development of antivirulence therapies against the emerging pathogen <i>C. haemolyticum</i>.</p>","PeriodicalId":18315,"journal":{"name":"mBio","volume":" ","pages":"e0360524"},"PeriodicalIF":5.1,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural elements of cyanobacterial co-factor-independent phosphoglycerate mutase that mediate regulation by PirC.","authors":"Tim Orthwein, Janette T Alford, Nathalie Sofie Becker, Phillipp Fink, Karl Forchhammer","doi":"10.1128/mbio.03378-24","DOIUrl":"10.1128/mbio.03378-24","url":null,"abstract":"<p><p>The 2,3-bisphosphoglycerate-independent phosphoglycerate mutase (iPGAM) has been identified as a regulating key point in the carbon storage metabolism of cyanobacteria. Upon nitrogen starvation, the iPGAM is inhibited by the P_II-interacting regulator PirC, which is released from its interaction partner P_II due to elevated 2-oxoglutarate levels. <i>In silico</i> analysis of 338 different iPGAMs revealed a deep-rooted distinctive evolution of iPGAMs in cyanobacteria. Remarkably, cyanobacterial iPGAMs possess a unique loop structure and an extended C-terminus. Our mass photometry analysis suggests that iPGAM forms a complex with three individual PirC monomers. Biolayer interferometry revealed that the PirC-iPGAM complex is affected by the unique loop and the C-terminal structural elements of iPGAM. A C-terminally truncated iPGAM enzyme showed loss of control by PirC and twofold increased enzymatic activity compared to the iPGAM-WT (wild type), as demonstrated by enzyme assays. By contrast, deleting the loop structure significantly reduced the activity of this variant. Physiological experiments were carried out with different iPGAM variant strains of <i>Synechocystis</i>, in which these structural elements were deleted. The strain expressing the C-terminally truncated iPGAM showed a similar overproduction of polyhydroxybutyrate as deletion of the iPGAM regulator PirC. However, in contrast to the latter, these strains showed higher overall biomass accumulation, making them a better chassis for the production of polyhydroxybutyrate or other valuable substances than the PirC-deficient mutant.IMPORTANCEThe primordial cyanobacteria were responsible for developing oxygenic photosynthesis early in evolution. In the pathways of fixed carbon allocation, the co-factor-independent phosphoglycerate mutase (iPGAM) plays a crucial role by directing the first CO₂ fixation product, 3-phosphoglycerate, toward central anabolic glycolytic-derived pathways. This work reveals a distinct evolution of iPGAM within oxygenic photosynthetic organisms. We have identified two specific segments in cyanobacterial iPGAMs that affect the control of iPGAM activity through its specific interactor protein PirC. This understanding of iPGAM has allowed us to engineer cyanobacterial strains with altered carbon fluxes. Since cyanobacteria can directly convert CO₂ into valuable products, our results demonstrate a novel approach for developing a chassis for biotechnical use.</p>","PeriodicalId":18315,"journal":{"name":"mBio","volume":" ","pages":"e0337824"},"PeriodicalIF":5.1,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Signaling pathways governing the pathobiological features and antifungal drug resistance of <i>Candida auris</i>.","authors":"Hyunjin Cha, Doyeon Won, Yong-Sun Bahn","doi":"10.1128/mbio.02475-23","DOIUrl":"https://doi.org/10.1128/mbio.02475-23","url":null,"abstract":"<p><p><i>Candida auris</i> is an emerging multidrug-resistant fungal pathogen that poses a significant global health threat. Since its discovery in 2009, <i>C. auris</i> has rapidly spread worldwide, causing severe infections with high mortality rates, particularly in healthcare settings. Its ability to persist in the environment, form biofilms, and resist multiple antifungal drugs underscores the urgent need to understand its pathogenicity mechanisms and associated signaling pathways. Such insights are crucial for elucidating its unique virulence traits and developing targeted therapeutic strategies. Current studies have identified several key pathways involved in its pathogenicity and antifungal drug resistance. The Ras/cAMP/PKA pathway regulates critical virulence factors, including thermotolerance, morphological plasticity, and biofilm formation. The mitogen-activated protein kinase (MAPK) and calcineurin pathways contribute to stress responses and antifungal drug resistance. The regulation of Ace2 and morphogenesis (RAM) pathway influences cell aggregation, while the target of rapamycin (TOR) pathway affects filamentous growth and biofilm development. However, the distinct characteristics of <i>C. auris</i>, such as its rapid environmental spread and clade-specific traits, warrant further investigation into additional signaling pathways. This review provides a comprehensive analysis of known signaling pathways associated with <i>C. auris</i> pathogenicity and antifungal drug resistance, integrating insights from other fungal pathogens. By synthesizing current knowledge and identifying research gaps, this review offers new perspectives on future research directions and potential therapeutic targets against this formidable pathogen.</p>","PeriodicalId":18315,"journal":{"name":"mBio","volume":" ","pages":"e0247523"},"PeriodicalIF":5.1,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic induction of PGE2 by oral pathogens and TNF promotes gingival fibroblast-driven stromal-immune cross-talk in periodontitis.","authors":"Elwira Nieboga, Aureliusz Schuster, Dominika M Drapala, Mariia Melnykova, Aleksander Gut, Weronika Lipska, Mateusz Kwitniewski, Marcin Migaczewski, Marta Czesnikiewicz-Guzik, Tomasz Kaczmarzyk, Jan Potempa, Aleksander M Grabiec","doi":"10.1128/mbio.00046-25","DOIUrl":"https://doi.org/10.1128/mbio.00046-25","url":null,"abstract":"<p><p>The interaction between pathogenic microorganisms and stromal cells, in particular fibroblasts, significantly contributes to the pathogenesis of many bacterially driven diseases. In periodontitis, oral pathogens penetrate the epithelial barrier and aggravate ongoing gingival inflammation by promoting the production of inflammatory mediators, such as prostaglandin E2 (PGE2). This study aimed to investigate the functional consequences of the interplay between oral pathogens and a pro-inflammatory environment in the activation of the PGE2 pathway in primary human gingival fibroblasts (GFs). GF infection with <i>Fusobacterium nucleatum</i>, <i>Porphyromonas gingivalis,</i> or <i>Filifactor alocis</i> in the presence of tumor necrosis factor (TNF) led to synergistic induction of cyclooxygenase-2 (COX-2), a key enzyme in the PGE2 synthesis pathway, as well as secretion of PGE2. A similar synergy in COX-2 upregulation was observed upon GF infection with oral pathogens in the presence of IL-1α, IL-1β, and interferon-α (IFN-α). This effect required toll-like receptor-2 (TLR2) and the p38 MAP kinase activation and was specific for fibroblasts as infection of macrophages or keratinocytes with oral pathogens in the proinflammatory environment did not cause synergistic COX-2 induction. Finally, we demonstrated that conditioned media from GFs infected with <i>F. nucleatum</i> under inflammatory conditions amplified the expression of the neutrophil chemokine <i>IL8</i> in macrophages and confirmed that this effect was mediated by synergistic induction of PGE2 in GFs. Collectively, we identify a new mechanism of stromal-immune cross-talk that is driven by synergistic PGE2 induction by oral pathogens and inflammatory cytokines in GFs and may contribute to excessive macrophage activation and neutrophil infiltration in periodontitis.IMPORTANCEPeriodontitis is a highly prevalent, dysbiosis-driven chronic inflammatory disease that not only leads to tooth loss but also is associated with severe systemic diseases. In this work, we describe a novel mechanism responsible for excessive production of PGE2, which is a potent inflammatory mediator that significantly contributes to the pathogenesis of periodontitis. We found that infection of GFs with many species of oral pathogens in the presence of inflammatory cytokines produced by the host leads to synergistic induction of COX-2 expression and PGE2 production. We found that this fibroblast-specific amplification of the COX-2-PGE2 axis by oral pathogens and cytokines is driven by the p38 MAP kinase and promotes enhanced expression of a key neutrophil chemokine by macrophages. These studies have thus enabled the identification of a new mechanism of host-pathogen interactions in periodontitis, improving our understanding of the roles of GFs and their cross-talk with immune cells in disease pathogenesis.</p>","PeriodicalId":18315,"journal":{"name":"mBio","volume":" ","pages":"e0004625"},"PeriodicalIF":5.1,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}