mSphere最新文献

{"title":"Dissolved oxygen concentrations influence microbial community structure and key players in an oxygen minimum zone.","authors":"Kaitlin R Dombroski, Lauren G Campbell, Robert M Morris, Olivia U Mason","doi":"10.1128/msphere.00751-25","DOIUrl":"10.1128/msphere.00751-25","url":null,"abstract":"<p><p>Oxygen minimum zones (OMZs) are expanding in the global ocean. Declining oxygen can alter microbial processes that regulate carbon, nitrogen, and sulfur cycling, including pathways with the potential to produce nitrous oxide (N₂O), a potent greenhouse gas. Yet, we lack a full understanding of how microbial communities respond to declining oxygen in some globally important OMZs. This is particularly true for the understudied northern Benguela Upwelling System (nBUS), an important source of marine N₂O. Here, we analyzed the influence of oxygen concentrations on microbial communities in the nBUS OMZ using 16S rRNA gene sequence data. Microbial diversity did not decline linearly with oxygen and was highest under dysoxic (0.2-2.0 mL/L) conditions and lowest under suboxic (0.0-0.2 mL/L) conditions. This pattern was primarily due to changes in community evenness, which decreased in suboxic samples as the relative abundance of <i>Thioglobaceae</i> (SUP05) increased. <i>Thioglobaceae</i> relative abundance was significantly inversely correlated with oxygen, and <i>Thioglobaceae</i> were abundant in the nBUS OMZ. Analysis of 216 publicly available medium- to high-quality <i>Thioglobaceae</i> genomes from cultured and uncultured microbes sampled in the nBUS and other OMZs revealed the metabolic potential of this clade for carbon fixation and consumption, sulfur oxidation, and denitrification. Importantly, few <i>Thioglobaceae</i> possess the genetic potential to carry out complete denitrification as most lack the gene that converts N₂O to dinitrogen gas. As OMZs expand in size and severity, decreasing microbial diversity and a concomitant increase in the relative abundance of <i>Thioglobaceae</i> could contribute to enhanced N₂O production through incomplete denitrification.IMPORTANCEMarine microbes mediate biogeochemical cycles, which are influenced by oxygen concentrations, including microbial pathways that can lead to nitrous oxide (N₂O) production. The oxygen minimum zone (OMZ) in the northern Benguela Upwelling System (nBUS) is a biogeochemical hotspot and an important source of nitrous oxide. Yet, microbial community responses remain poorly characterized in this understudied OMZ. Analysis of microbial communities in this OMZ, combined with comparative genomic analysis of <i>Thioglobaceae</i> from the global ocean, revealed that members of this group have the capacity to fix carbon, potentially supporting growth through sulfur oxidation coupled to denitrification. However, few <i>Thioglobaceae</i> have the genetic potential to carry out complete denitrification, with the final nitrous oxide reduction step often missing. Incomplete denitrification is an important source of N₂O in OMZs. Collectively, this study linked oxygen-associated community shifts in this OMZ to incomplete denitrification in a microbial group that increased in relative abundance as oxygen declined.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0075125"},"PeriodicalIF":4.0,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13508795/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148448362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phenotypic diversity and shared genomic determinants among isolates causing a large incidence of disseminated gonococcal infections in Canada.","authors":"Gursonika Binepal, Emil Jurga, Duncan Carruthers-Lay, Sören Krüger, Sandra Zittermann, Jessica Minion, Mathew Diggle, David C Alexander, Irene Martin, Vanessa Allen, John Parkinson, Scott D Gray-Owen","doi":"10.1128/msphere.00051-26","DOIUrl":"10.1128/msphere.00051-26","url":null,"abstract":"<p><p>The incidence of disseminated gonococcal infection (DGI) has remained low since the advent of antibiotics; however, a recent surge in DGI has inexplicably emerged during the past decade. In an effort to understand whether <i>Neisseria gonorrhoeae</i> that cause disseminated disease can be differentiated from non-invasive strains, we have performed a phenotypic and genotypic analysis on a selection of isolates obtained from invasive and uncomplicated infections in Canada. The increase in DGI was initially associated with a single antibiotic-susceptible gonococcal lineage, but later cases have been caused by diverse strains. Phenotypic analysis of a matched subset of 20 isolates obtained since 2013 found that these varied in their capacity to aggregate in suspension and in their association with serum complement proteins; however, these interactions did not discriminate between the invasive and mucosal isolates. Sequence typing of 360 Canadian isolates revealed that two variant porBa alleles are significantly associated with the DGI strains, one of these being present throughout the past decade, whereas the other emerged more recently. A PopNet-based population dynamics analysis, which instead establishes relationships based upon variance among discrete chromosomal segments, revealed that DGI isolates were restricted to distinct subpopulations within their phylogenetic distribution, implying a genetically linked potential to cause invasive disease. Consistent with this, a large number of genetic determinants are enriched in the DGI strains, making these enticing candidates to explain the increased capacity of <i>N. gonorrhoeae</i> to cause systemic infection and/or reduce the presentation of clinical symptoms from localized infection so that it remains untreated.IMPORTANCEThe re-emergence of disseminated gonococcal infections (DGIs) has raised concern that the virulence of some strains has increased due to their acquisition of a new capacity to remain asymptomatic during uncomplicated mucosal infection and/or to invade the bloodstream and persist upon establishing colonization at distal tissue sites. The molecular epidemiology of a very large incidence of DGI in Canada, which began from a single strain but then diversified with time, provided an opportunity to understand whether the invasive isolates were either phenotypically or genotypically related. While classical phenotypic analysis did not discriminate between mucosal and invasive isolates, a population dynamics-based approach established that the DGI isolates are present within distinct subpopulations of <i>Neisseria gonorrhoeae</i> and reveals genetic determinants that are linked to this phenotype. This suggests that the DGI phenotype emerged multiple times independently and/or the genetic features responsible have been transmitted among the populations.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0005126"},"PeriodicalIF":4.0,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13508793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148520648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Label-free quantification of early virus-induced cellular responses by digital holographic tomography.","authors":"Agata Kublicka, Igor Buzalewicz, Dominika Skrzela, Leszek Moniakowski, Devon K S Fuller, Aleksandra Chwirot, Maja Marynowska, Grzegorz Chodaczek, Barbara Bażanów, Anna Karolina Matczuk","doi":"10.1128/msphere.00304-26","DOIUrl":"10.1128/msphere.00304-26","url":null,"abstract":"<p><p>Early virus-induced cellular responses are a fundamental diagnostic feature of viral infections; however, early virus-host interactions, particularly during viral entry, remain difficult to study in living cells because many commonly used markers and antibodies require fixation or can interfere with cell viability. Although virus-induced cellular responses constitute a fundamental diagnostic feature of viral infections, their detection by microscopy typically relies on later-stage effects. Microscopic observation, therefore, serves as a complementary approach to molecular techniques, but the time required for visible changes to develop limits its utility for rapid assessment. Here, we propose a label-free digital holotomography (DHT) approach for the detection of early virus-induced cellular responses during the first hours of infection, including equine arteritis virus (EAV), equine herpesvirus 1 (EHV-1), and equine rhinitis B virus (ERBV). Using this method, we show that as early as 1-2 h post-infection, holotomography is capable of capturing virus-induced alterations in cellular density based only on changes in the refractive index (RI), which reflects local variations in cellular mass density and biochemical composition. In addition to global RI changes, we focused on subcellular alterations occurring at the early stages of infection, including modifications in lipid droplet-like structures and nucleoli. Our results reveal that these changes become detectable rapidly and can be captured with high sensitivity, displaying both cell type- and virus-dependent patterns. Our findings suggest that DHT may provide a rapid, label-free, and quantitative platform for detecting virus-induced subcellular changes as early as 1-2 h post-infection.</p><p><strong>Importance: </strong>Digital holotomography (DHT) facilitates the early, label-free detection of infection and serves as a complementary diagnostic tool, allowing the rapid initiation of treatment. This method is universal and can be broadly applied to the investigation of primary host interactions, including general cellular and biomolecular optical density changes. These applications provide a strong foundation for viral entry inhibitor testing. Moreover, this approach highlights the critical importance of studying viral infections in natural host systems rather than relying solely on well-established experimental models. In this context, we employed equine lung cells (ELCs) as a biologically relevant and appropriate model to better reflect natural host-virus interactions. These findings should be interpreted in the context of an exploratory imaging data set and will require confirmation in replicate-based and longitudinal single-cell studies.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0030426"},"PeriodicalIF":4.0,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13508796/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148670116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"mSphere of Influence: Mapping tRNA epitranscriptome by sequencing.","authors":"Satoshi Kimura","doi":"10.1128/msphere.00328-26","DOIUrl":"10.1128/msphere.00328-26","url":null,"abstract":"<p><p>Satoshi Kimura works in the field of RNA modification. In this mSphere of Influence article, he reflects on how the paper \"Efficient and quantitative high-throughput tRNA sequencing\" by G. Zheng, Y. Qin, W. C. Clark, Q. Dai, et al. (Nat. Methods 12:835-837, 2015, https://doi.org/10.1038/nmeth.3478) has impacted him by demonstrating that deep sequencing technology is harnessed to profile tRNA modifications.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0032826"},"PeriodicalIF":4.0,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13508785/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148520559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sorbose metabolism promotes fitness and virulence in <i>Escherichia coli</i>.","authors":"Xue Deng, Cong Shen, Lingjuan Chen, Dandan Sun, Tian Qiu, Zihan Zhao, Tong Li, Guili Zhang, Ji Wu, Juan Wang, Guo-Bao Tian, Lingqing Xu, Bin Yan, Lan-Lan Zhong","doi":"10.1128/msphere.00191-26","DOIUrl":"10.1128/msphere.00191-26","url":null,"abstract":"<p><p>The plasmid-borne <i>mcr-1</i> gene poses a significant threat to global health by conferring resistance to colistin, a critical last-resort antibiotic. While its spread is well documented, the adaptations enabling its concurrent antibiotic resistance and clinical pathogenicity remain unknown. The metabolism of bacterial pathogens has evolved to support virulence in nutrient-limiting host environments. Here, we show that sorbose metabolism promotes the fitness and virulence of <i>mcr-1-</i>positive <i>Escherichia coli</i> (MCRPEC), but does not affect its resistance to colistin or polymyxin B. Notably, the virulence contribution is also observed in an <i>mcr-1</i>-negative background. Genetic disruption of sorbose catabolism (Δ<i>sorD</i>) attenuated MCRPEC virulence and fitness both <i>in vitro</i> and <i>in vivo</i>. Integrated transcriptomic and metabolomic analyses suggest that this attenuation is associated with impaired expression of two major virulence determinants. First, defective sorbose metabolism limits the supply of monosaccharide precursors required for LPS biosynthesis, leading to reduced LPS content. Second, metabolic disruption decreases intracellular cAMP levels, which downregulates <i>fimH</i> expression via a cAMP-dependent signaling pathway, thereby compromising bacterial adhesion. Notably, although <i>sorD</i> deletion enhances biofilm formation, this increase is insufficient to rescue the <i>in vivo</i> virulence defect. Restoration of the sorbose metabolic pathway partially rescues MCRPEC pathogenicity. These findings suggest that sorbose metabolism contributes to MCRPEC pathogenicity by supporting LPS synthesis and regulating <i>fimH</i> expression via cAMP signaling. This study indicates a metabolic link between sorbose utilization and MCRPEC pathogenicity, raising the possibility that sorbose, a common food additive, could facilitate MCRPEC pathogenicity.IMPORTANCEThe spread of colistin-resistant <i>Escherichia coli</i> (<i>E. coli</i>) limits treatment options for life-threatening infections. This study shows that sorbose metabolism, which utilizes a common dietary sugar, contributes to the fitness and virulence of such resistant bacteria without affecting their colistin resistance. Using <i>mcr-1</i>-positive <i>E. coli</i>, we find that this metabolic pathway supports lipopolysaccharide synthesis and, via a cAMP-dependent mechanism, promotes bacterial adhesion. Disabling sorbose catabolism attenuates the pathogen in animal models. These findings suggest a previously unrecognized link between a specific carbohydrate metabolism and pathogenesis in drug-resistant <i>E. coli</i>, raising the possibility that dietary components may influence infection outcomes.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0019126"},"PeriodicalIF":4.0,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13410766/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148252179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Salinity-driven microbial adaptation of hydrocarbon-degrading communities in coastal sediments.","authors":"Yongyi Peng, Qing Liu, Xianbiao Lin, Fengmin Xing, Shengjie Li, Xinyue Liu, Yingchun Han, Yanbin Chen, Xiyang Dong","doi":"10.1128/msphere.00369-26","DOIUrl":"10.1128/msphere.00369-26","url":null,"abstract":"<p><p>Salinity is a major abiotic driver of microbial diversity and metabolic function in coastal ecosystems. While its broad ecological impacts are well established, its role in shaping hydrocarbon-degrading communities and their adaptive mechanisms remains poorly understood. Here, we integrated gene- and genome-resolved metagenomics to investigate how salinity regulates the diversity, ecological interactions, and evolutionary dynamics of aerobic hydrocarbon-degrading microbes in Zhenhai Bay sediments (0.17-28.54 practical salinity units [PSU]). Across the natural salinity gradient, 10 types of hydrocarbon-degrading genes and 30 bacterial genomes spanning four phyla were identified, revealing extensive metabolic potential for the aerobic degradation of both aliphatic and aromatic hydrocarbons. The functional diversity and relative abundance of these genes increased significantly with salinity, accompanied by strong correlations with organic carbon parameters and nitrogen availability. Co-occurrence network analyses showed that hydrocarbon degraders, particularly <i>Gammaproteobacteria</i>, acted as key taxa maintaining community stability under saline conditions. Comparative genomics revealed that these bacteria possess multiple halotolerance strategies, including compatible solute biosynthesis and ion transport, supported by diverse energy-generating pathways. Frequent horizontal gene transfer and duplication of alkane monooxygenases (<i>alkB</i> and <i>cyp153</i>) expanded substrate ranges and enhanced functional diversity in hydrocarbon oxidation, highlighting salinity-driven evolutionary innovation. Together, these findings demonstrate that salinity governs the structure, metabolism, and evolution of hydrocarbon-degrading microbes, promoting microbial adaptation and functional diversification in coastal sediments.IMPORTANCESalinity is a defining feature of coastal ecosystems and a major regulator of microbial processes that support carbon cycling and pollutant degradation. This study highlights that salinity plays a central role in structuring hydrocarbon-degrading microbial communities and shaping their functional capacities and evolutionary trajectories in coastal sediments. By integrating osmoadaptation, metabolic potential, and community organization, our work shows that hydrocarbon degraders function as key links between environmental conditions and ecological processes. Salinity-driven shifts in microbial networks and metabolic strategies illustrate how environmental gradients can foster resilience and stability in highly dynamic coastal systems. Beyond advancing understanding of microbial responses, this study has potential implications for the rational design of bioremediation strategies targeting hydrocarbon pollutants in saline and estuarine environments.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0036926"},"PeriodicalIF":4.0,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13410759/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148369068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kiss and spit metabolomics highlight the role of host purine metabolism during pathogen infection.","authors":"Gina M Gallego-Lopez, William J Olson, Andres M Tibabuzo-Perdomo, David Stevenson, Daniel Amador-Noguez, Grant Lawrence, James W Leahy, Emmanuel Contreras Guzman, Melissa C Skala, Laura J Knoll","doi":"10.1128/msphere.00256-26","DOIUrl":"10.1128/msphere.00256-26","url":null,"abstract":"<p><p>Intracellular bacteria and protists rely on the host cell to supply many metabolites, but the mechanisms through which pathogens manipulate host metabolism to their benefit are not understood. Here, we demonstrate that when the obligate intracellular parasite <i>Toxoplasma gondii</i> secretes its rhoptry organelle contents into the host cytoplasm before invasion-a process called \"kiss and spit\"-host cell metabolite abundance is altered in nucleotide synthesis, the pentose phosphate pathway, glycolysis, and amino acid synthesis. U-13C6-labeling metabolomics confirmed that kiss and spit increased the flow of carbon through the pentose phosphate pathway and nucleotide synthesis. An increase in 2,3-bisphosphoglycerate abundance led us to investigate the activation of host cytosolic nucleosidase II (cN-II) to provide purines for the parasite. We found that <i>T. gondii</i> manipulates the host cN-II enzyme to dephosphorylate GMP and IMP that it needs for replication. Furthermore, we found that the approved anti-cancer drug fludarabine, which inhibits cN-II, also inhibits <i>Toxoplasma</i> replication. These results reveal <i>Toxoplasma</i> host cell manipulation and highlight potential therapies for toxoplasmosis.IMPORTANCEA fundamental challenge in parasitology is understanding how intracellular parasites rapidly reprogram host metabolism to support replication. This study reveals that <i>Toxoplasma gondii</i> initiates profound metabolic reprogramming through a \"kiss-and-spit\" mechanism, secreting effector molecules without invasion. We demonstrate that <i>T. gondii</i> specifically hijacks host cytosolic 5'-nucleotidase II (cN-II) by elevating 2,3-bisphosphoglycerate levels, which allosterically activates this enzyme to generate purines essential for parasite survival. Genetic deletion of host cN-II significantly impairs parasite replication, establishing cN-II as a critical host dependency factor. These findings have important implications for antiparasitic drug development while advancing our understanding of purine metabolism in apicomplexan parasites. More broadly, elucidating the molecular mechanism linking parasite effector secretion to specific host enzyme activation provides a framework for understanding metabolic manipulation across other intracellular pathogens.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0025626"},"PeriodicalIF":4.0,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13410994/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148251861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Auxotrophy from bioenergetic demand: the case of proline addiction in <i>Clostridioides difficile</i>.","authors":"Michael A Johnstone, William T Self","doi":"10.1128/msphere.00246-26","DOIUrl":"10.1128/msphere.00246-26","url":null,"abstract":"<p><p>Many microbial growth requirements are interpreted as auxotrophy arising from loss of biosynthetic capacity. <i>Clostridioides difficile</i> is widely considered to be proline auxotrophic because it fails to grow in defined media lacking proline, yet it harbors proline biosynthesis genes. Because <i>C. difficile</i> preferentially uses proline as an electron acceptor via D-proline reductase (Prd), we argue that this phenotype arises from a bioenergetic constraint rather than an inability to make proline. Consistent with this view, mutants lacking Prd gain the ability to grow without proline. Moreover, conditions that adapt the organism to Prd-independent redox metabolism, such as Wood-Ljungdahl-linked acetobutyrogenesis, also enable proline-independent growth. We propose a model for \"proline addiction\" in which sustained Prd flux depletes the intracellular proline pool faster than biosynthesis can replenish it, making growth dependent on environmental proline. This bioenergetic addiction model may help explain cryptic auxotrophies that genome-based cultivation approaches would otherwise miss.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0024626"},"PeriodicalIF":4.0,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13410763/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148339482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preclinical characterization of immune responses induced by a candidate gonococcal native outer membrane vesicle vaccine.","authors":"Ilaria Onofrio, Sthefany Pagliari, Ayah Francis, Molly E Quinn, Thomas Belcher, Senuri N Dissanayake, Clement Twumasi, Iason Vichos, Lukasz A Grudzein, Christine S Rollier, Calman A MacLennan","doi":"10.1128/msphere.00174-26","DOIUrl":"10.1128/msphere.00174-26","url":null,"abstract":"&lt;p&gt;&lt;p&gt;&lt;i&gt;Neisseria gonorrhoeae&lt;/i&gt; poses significant public health challenges due to multidrug-resistant gonorrhea and severe reproductive health complications of untreated infection. No vaccine is licensed to prevent gonorrhea. However, the meningococcal outer membrane vesicle (OMV)-containing vaccine, 4CMenB, provides moderate cross-protection against gonorrhea. We have recently demonstrated that immunization with gonococcal OMV accelerates clearance of gonococcal infection in mice compared with 4CMenB. To gain insight into possible mechanisms of protection of gonococcal OMV, we evaluated the immunogenicity of GonoVac, a candidate native OMV (nOMV) vaccine against gonorrhea, in mice and rabbits. Three doses of GonoVac were administered intramuscularly from 0.15 to 5 µg in mice, and four doses were used to immunize rabbits at 50 µg per dose, formulated with or without aluminum hydroxide [Al(OH)&lt;sub&gt;3&lt;/sub&gt;]. Systemic and mucosal antibody responses were evaluated by enzyme-linked immunosorbent assay (ELISA) and serum bactericidal assay (SBA). Cellular responses were assessed by enzyme-linked immunosorbent spot (ELISpot3). Immunization with GonoVac formulated with and without Al(OH)&lt;sub&gt;3&lt;/sub&gt; induced significantly higher levels of gonococcal serum and vaginal IgG, and serum bactericidal antibodies, compared with 4CMenB, which induced no serum killing activity. Serum bactericidal activity of GonoVac correlated with anti-gonococcal IgG2a and IgG3 levels. Serum IgA levels were minimal. Cellular immune responses were higher in mice receiving GonoVac/Al(OH)&lt;sub&gt;3&lt;/sub&gt; compared with GonoVac alone. Immunogenicity was similar for GonoVac produced in a bioreactor and shake flasks. GonoVac elicits robust and functional immune responses in mice and rabbits compared with 4CMenB, supporting its further development as a promising candidate vaccine against gonorrhea.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Importance: &lt;/strong&gt;Gonorrhea, caused by &lt;i&gt;Neisseria gonorrhoeae&lt;/i&gt;, remains a significant global health concern, disproportionately affecting populations in low- and middle-income countries (LMICs), particularly women. The emergence of multidrug-resistant strains of &lt;i&gt;N. gonorrhoeae&lt;/i&gt; has raised the concern of untreatable gonorrhea, underscoring the urgent need for effective preventive measures. Although there is no licensed vaccine against gonorrhea, the meningococcal OMV-based vaccine, 4CMenB, is partially effective against the disease and has been recommended for use in high-risk groups. In this article, we build on previous findings of enhanced efficacy of gonococcal OMV vaccine candidates compared with 4CMenB in the mouse gonococcal infection model to demonstrate the superior anti-gonococcal immunogenicity of a gonococcal OMV-based candidate vaccine (GonoVac) compared with 4CMenB. GonoVac elicits robust immunity in mice, inducing antibodies that are able to kill gonococci, whereas 4CMenB does not. The findings highlight the potential of GonoVac as a promising vaccine can","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0017426"},"PeriodicalIF":4.0,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13410757/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148339426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TRP120-dependent activation of noncanonical Wnt/NFAT signaling drives monocyte chemokine production in <i>Ehrlichia chaffeensis</i> infection.","authors":"Regina N Solomon, Duc-Cuong Bui, Ayana P Pai, Jere W McBride","doi":"10.1128/msphere.00081-26","DOIUrl":"10.1128/msphere.00081-26","url":null,"abstract":"<p><p><i>Ehrlichia chaffeensis</i> is an obligately intracellular bacterium that repurposes multiple cellular signaling pathways, including Wnt, Hippo, Notch, and Hedgehog to evade innate immune defenses of mononuclear phagocytes. Although noncanonical Wnt signaling activation by <i>E. chaffeensis</i> induces nuclear factor of activated T-cells (NFAT) activity, the functional consequences of this response have remained unclear. Here, we demonstrate that <i>E. chaffeensis</i> exploits noncanonical Wnt/Ca²⁺ signaling to selectively activate NFATc1 and drive monocyte chemotactic chemokine production. In <i>E. chaffeensis-</i>infected THP-1 cells, NFATc1 was exclusively activated, which was recapitulated in cells treated with soluble recombinant TRP120 (rTRP120) or TRP120 Wnt ligand short linear motif (SLiM) peptide (QDVASH). Correspondingly, significant increases and similar chemokine expression profiles were detected in THP-1 cells infected with <i>E. chaffeensis</i> or treated with soluble rTRP120. Moreover, treatment with the NFATc1 peptide inhibitor (11R-VIVIT) significantly inhibited NFAT activation and chemokine expression. Consistent with a requirement for Wnt signaling, Frizzled 5 (FZD5)-deficient THP-1 cells exhibited reduced NFATc1 activation and diminished chemokine production and monocyte recruitment. Although the TRP120 Wnt ligand SLiM phenocopied <i>E. chaffeensis-</i>induced NFATc1 activation, it was insufficient to independently stimulate chemokine production. In contrast, ectopic expression of TRP120-induced chemokine expression, which was further amplified by TRP120 Wnt SLiM treatment, indicating both TRP120-directed extracellular Wnt signaling and intracellular mechanisms are required. Collectively, these findings define a previously unrecognized pathogen-driven strategy that co-opts non-canonical Wnt/NFAT signaling to promote monocyte chemotactic chemokine production.IMPORTANCE<i>Ehrlichia chaffeensis</i> is an obligately intracellular bacterium that causes human monocytic ehrlichiosis and survives within mononuclear phagocytes by manipulating key cell signaling pathways. Unlike most Gram-negative bacteria, <i>E. chaffeensis</i> lacks classical pathogen-associated molecular patterns such as lipopolysaccharide and peptidoglycan, yet it stimulates strong chemokine production during infection; however, the molecular patterns, receptors and signaling pathways involved in inducing chemokine expression are unknown. Here, we uncover a cell signaling strategy whereby <i>E. chaffeensis</i>, through TRP120 Wnt ligand mimicry, co-opts the noncanonical Wnt/Ca²⁺ signaling to selectively activate NFATc1 and drive chemokine expression. This pathogen-driven NFAT activation promotes monocyte recruitment, revealing a previously unrecognized chemokine induction mechanism.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0008126"},"PeriodicalIF":4.0,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13410762/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148295777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}