PLoS Pathogens最新文献

{"title":"Purified CDT toxins and a clean deletion within the CDT locus provide novel insights into the contribution of binary toxin in cellular inflammation and Clostridioides difficile infection.","authors":"Kateryna Nabukhotna, Shannon L Kordus, John A Shupe, Rubén Cano Rodríguez, Anna Smith, Julia K Bohannon, M Kay Washington, D Borden Lacy","doi":"10.1371/journal.ppat.1012568","DOIUrl":"10.1371/journal.ppat.1012568","url":null,"abstract":"<p><p>Clostridioides difficile is a spore-forming pathogen and the most common cause of healthcare-associated diarrhea and colitis in the United States. Besides producing the main virulence factors, toxin A (TcdA) and toxin B (TcdB), many of the common clinical strains encode the C. difficile transferase (CDT) binary toxin. The role of CDT in the context of C. difficile infection (CDI) is poorly understood. Inflammation is a hallmark of CDI and multiple mechanisms of inflammasome activation have been reported for TcdA, TcdB, and the organism. Some studies have suggested that CDT contributes to this inflammation through a TLR2-dependent priming mechanism that leads to the suppression of protective eosinophils. Here, we show that CDT does not prime but instead activates the inflammasome in bone marrow-derived dendritic cells (BMDCs). In bone marrow-derived macrophages (BMDMs), the cell binding and pore-forming component of the toxin, CDTb, alone activates the inflammasome and is dependent on K+ efflux. The activation is not observed in the presence of CDTa and is not observed in BMDMs derived from Nlrp3-/- mice suggesting the involvement of the NLRP3 inflammasome. However, we did not observe evidence of CDT-dependent inflammasome priming or activation in vivo. Mice were infected with R20291 and an isogenic CRISPR/Cas9-generated R20291 ΔcdtB strain of C. difficile. While CDT contributes to increased weight loss and cecal edema at 2 days post infection, the relative levels of inflammasome-associated cytokines, IL-1β and IL-18, in the cecum and distal colon are unchanged. We also saw CDT-dependent weightloss in Nlrp3-/- mice, suggesting that the increased weightloss associated with the presence of CDT is not a result of NLRP3-dependent inflammasome activation. This study highlights the importance of studying gene deletions in the context of otherwise fully isogenic strains and the challenge of translating toxin-specific cellular responses into a physiological context, especially when multiple toxins are acting at the same time.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11444381/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142299247","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":"Mechanism of enterovirus VP0 maturation cleavage based on the structure of a stabilised assembly intermediate.","authors":"Natalie J Kingston, Joseph S Snowden, Keith Grehan, Philippa K Hall, Eero V Hietanen, Tim C Passchier, Stephen J Polyak, David J Filman, James M Hogle, David J Rowlands, Nicola J Stonehouse","doi":"10.1371/journal.ppat.1012511","DOIUrl":"10.1371/journal.ppat.1012511","url":null,"abstract":"<p><p>Molecular details of genome packaging are little understood for the majority of viruses. In enteroviruses (EVs), cleavage of the structural protein VP0 into VP4 and VP2 is initiated by the incorporation of RNA into the assembling virion and is essential for infectivity. We have applied a combination of bioinformatic, molecular and structural approaches to generate the first high-resolution structure of an intermediate in the assembly pathway, termed a provirion, which contains RNA and intact VP0. We have demonstrated an essential role of VP0 E096 in VP0 cleavage independent of RNA encapsidation and generated a new model of capsid maturation, supported by bioinformatic analysis. This provides a molecular basis for RNA-dependence, where RNA induces conformational changes required for VP0 maturation, but that RNA packaging itself is not sufficient to induce maturation. These data have implications for understanding production of infectious virions and potential relevance for future vaccine and antiviral drug design.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11444389/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142299243","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":"Understanding the significance of oxygen tension on the biology of Plasmodium falciparum blood stages: From the human body to the laboratory.","authors":"Dinah S Nahid, Kevin A Coffey, Amy K Bei, Regina Joice Cordy","doi":"10.1371/journal.ppat.1012514","DOIUrl":"https://doi.org/10.1371/journal.ppat.1012514","url":null,"abstract":"<p><p>Plasmodium falciparum undergoes sequestration within deep tissues of the human body, spanning multiple organ systems with differing oxygen (O2) concentrations. The parasite is exposed to an even greater range of O2 concentrations as it transitions from the human to the mosquito host, suggesting a high level of plasticity as it navigates these different environments. In this review, we explore factors that may contribute to the parasite's response to different environmental O2 concentrations, recognizing that there are likely multiple pieces to this puzzle. We first review O2-sensing mechanisms, which exist in other apicomplexans such as Toxoplasma gondii and consider whether similar systems could exist in Plasmodium. Next, we review morphological and functional changes in P. falciparum's mitochondrion during the asexual-to-sexual stage transition and discuss how these changes overlap with the parasite's access to O2. We then delve into reactive oxygen species (ROS) as ROS production is influenced by O2 availability and oxidative stress impacts Plasmodium intraerythrocytic development. Lastly, given that the primary role of the red blood cell (RBC) is to deliver O2 throughout the body, we discuss how changes in the oxygenation status of hemoglobin, the RBC's O2-carrying protein and key nutrient for Plasmodium, could also potentially impact the parasite's growth during intraerythrocytic development. This review also highlights studies that have investigated P. falciparum biology under varying O2 concentrations and covers technical aspects related to P. falciparum cultivation in the lab, focusing on sources of technical variation that could alter the amount of dissolved O2 encountered by cells during in vitro experiments. Lastly, we discuss how culture systems can better replicate in vivo heterogeneity with respect to O2 gradients, propose ideas for further research in this area, and consider translational implications related to O2 and malaria.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11412506/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142299251","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":"The unappreciated role of developing B cells in chronic gammaherpesvirus infections.","authors":"Yiping Wang, April Feswick, Vasiliki Apostolou, Scott A Tibbetts","doi":"10.1371/journal.ppat.1012445","DOIUrl":"https://doi.org/10.1371/journal.ppat.1012445","url":null,"abstract":"","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11412639/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142299249","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":"Transcription modulation of pathogenic streptococcal and enterococcal species using CRISPRi technology.","authors":"Natalie G Alexander, William D Cutts, Thomas A Hooven, Brandon J Kim","doi":"10.1371/journal.ppat.1012520","DOIUrl":"10.1371/journal.ppat.1012520","url":null,"abstract":"","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142299250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation and characterization of IgG3 glycan-targeting antibodies with exceptional cross-reactivity for diverse viral families.","authors":"Matthew J Vukovich, Andrea R Shiakolas, Jared Lindenberger, Robert A Richardson, Lindsay E Bass, Maggie Barr, Yanshun Liu, Eden P Go, Chan Soo Park, Aaron J May, Salam Sammour, Chipo Kambarami, Xiao Huang, Katarzyna Janowska, Robert J Edwards, Katayoun Mansouri, Taylor N Spence, Alexandra A Abu-Shmais, Nelia P Manamela, Simone I Richardson, Sabina E W Leonard, Kathryn R Gripenstraw, Ian Setliff, Kevin O Saunders, Rachel H Bonami, Ted M Ross, Heather Desaire, Penny L Moore, Robert Parks, Barton F Haynes, Daniel J Sheward, Priyamvada Acharya, Giuseppe A Sautto, Ivelin S Georgiev","doi":"10.1371/journal.ppat.1012499","DOIUrl":"10.1371/journal.ppat.1012499","url":null,"abstract":"<p><p>Broadly reactive antibodies that target sequence-diverse antigens are of interest for vaccine design and monoclonal antibody therapeutic development because they can protect against multiple strains of a virus and provide a barrier to evolution of escape mutants. Using LIBRA-seq (linking B cell receptor to antigen specificity through sequencing) data for the B cell repertoire of an individual chronically infected with human immunodeficiency virus type 1 (HIV-1), we identified a lineage of IgG3 antibodies predicted to bind to HIV-1 Envelope (Env) and influenza A Hemagglutinin (HA). Two lineage members, antibodies 2526 and 546, were confirmed to bind to a large panel of diverse antigens, including several strains of HIV-1 Env, influenza HA, coronavirus (CoV) spike, hepatitis C virus (HCV) E protein, Nipah virus (NiV) F protein, and Langya virus (LayV) F protein. We found that both antibodies bind to complex glycans on the antigenic surfaces. Antibody 2526 targets the stem region of influenza HA and the N-terminal domain (NTD) region of SARS-CoV-2 spike. A crystal structure of 2526 Fab bound to mannose revealed the presence of a glycan-binding pocket on the light chain. Antibody 2526 cross-reacted with antigens from multiple pathogens and displayed no signs of autoreactivity. These features distinguish antibody 2526 from previously described glycan-reactive antibodies. Further study of this antibody class may aid in the selection and engineering of broadly reactive antibody therapeutics and can inform the development of effective vaccines with exceptional breadth of pathogen coverage.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11410209/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142299232","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":"HIV-1 diversity in viral reservoirs obtained from circulating T-cell subsets during early ART and beyond.","authors":"Yuepeng Zhang, Fabian Otte, Marcel Stoeckle, Alexander Thielen, Martin Däumer, Rolf Kaiser, Katharina Kusejko, Karin J Metzner, Thomas Klimkait","doi":"10.1371/journal.ppat.1012526","DOIUrl":"https://doi.org/10.1371/journal.ppat.1012526","url":null,"abstract":"<p><p>Even during extended periods of effective immunological control, a substantial dynamic of the viral genome can be observed in different cellular compartments in HIV-1 positive individuals, indicating the persistence of active viral reservoirs. To obtain further insights, we studied changes in the proviral as well as in the viral HIV-1 envelope (Env) sequence along with transcriptional, translational and viral outgrowth activity as indicators for viral dynamics and genomic intactness. Our study identified distinct reservoir patterns that either represented highly sequence-diverse HIV-1 populations or only a single / few persisting virus variants. The single dominating variants were more often found in individuals starting ART during early infection phases, indicating that early treatment might limit reservoir diversification. At the same time, more sequence-diverse HIV reservoirs correlated with a poorer immune status, indicated by lower CD4 count, a higher number of regimen changes and more co-morbidities. Furthermore, we noted that in T-cell populations in the peripheral blood, replication-competent HIV-1 is predominantly present in Lymph node homing TN (naïve) and TCM (central memory) T cells. Provirus genomes archived in TTM (transitional memory) and TEM (effector memory) T cells more frequently tended to carry inactivating mutations and, population-wise, possess changes in the genetic diversity. These discriminating properties of the viral reservoir in T-cell subsets may have important implications for new early therapy strategies, underscoring the critical role of early therapy in preserving robust immune surveillance and constraining the viral reservoir.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11410260/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142299231","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":"Peculiar transcriptional reprogramming with functional impairment of dendritic cells upon exposure to transformed HTLV-1-infected cells.","authors":"Auriane Carcone, Franck Mortreux, Sandrine Alais, Cyrille Mathieu, Chloé Journo, Hélène Dutartre","doi":"10.1371/journal.ppat.1012555","DOIUrl":"10.1371/journal.ppat.1012555","url":null,"abstract":"<p><p>Manipulation of immune cell functions, independently of direct infection of these cells, emerges as a key process in viral pathophysiology. Chronic infection by Human T-cell Leukemia Virus type 1 (HTLV-1) is associated with immune dysfunctions, including misdirected responses of dendritic cells (DCs). Here, we interrogate the ability of transformed HTLV-1-infected T cells to manipulate human DC functions. We show that exposure to transformed HTLV-1-infected T cells induces a biased and peculiar transcriptional signature in monocyte-derived DCs, associated with an inefficient maturation and a poor responsiveness to subsequent stimulation by a TLR4 agonist. This poor responsiveness is also associated with a unique transcriptional landscape characterized by a set of genes whose expression is either conferred, impaired or abolished by HTLV-1 pre-exposure. Induction of this functional impairment requires several hours of coculture with transformed HTLV-1-infected cells, and associated mechanisms driven by viral capture, cell-cell contacts, and soluble mediators. Altogether, this cross-talk between infected T cells and DCs illustrate how HTLV-1 might co-opt communications between cells to induce a unique local tolerogenic immune microenvironment suitable for its own persistence.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11426526/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142299246","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":"Generation of antigen-specific memory CD4 T cells by heterologous immunization enhances the magnitude of the germinal center response upon influenza infection.","authors":"Linda M Sircy, Andrew G Ramstead, Lisa C Gibbs, Hemant Joshi, Andrew Baessler, Ignacio Mena, Adolfo García-Sastre, Lyska L Emerson, Keke C Fairfax, Matthew A Williams, J Scott Hale","doi":"10.1371/journal.ppat.1011639","DOIUrl":"10.1371/journal.ppat.1011639","url":null,"abstract":"<p><p>Current influenza vaccine strategies have yet to overcome significant obstacles, including rapid antigenic drift of seasonal influenza viruses, in generating efficacious long-term humoral immunity. Due to the necessity of germinal center formation in generating long-lived high affinity antibodies, the germinal center has increasingly become a target for the development of novel or improvement of less-efficacious vaccines. However, there remains a major gap in current influenza research to effectively target T follicular helper cells during vaccination to alter the germinal center reaction. In this study, we used a heterologous infection or immunization priming strategy to seed an antigen-specific memory CD4+ T cell pool prior to influenza infection in mice to evaluate the effect of recalled memory T follicular helper cells in increased help to influenza-specific primary B cells and enhanced generation of neutralizing antibodies. We found that heterologous priming with intranasal infection with acute lymphocytic choriomeningitis virus (LCMV) or intramuscular immunization with adjuvanted recombinant LCMV glycoprotein induced increased antigen-specific effector CD4+ T and B cellular responses following infection with a recombinant influenza strain that expresses LCMV glycoprotein. Heterologously primed mice had increased expansion of secondary Th1 and Tfh cell subsets, including increased CD4+ TRM cells in the lung. However, the early enhancement of the germinal center cellular response following influenza infection did not impact influenza-specific antibody generation or B cell repertoires compared to primary influenza infection. Overall, our study suggests that while heterologous infection or immunization priming of CD4+ T cells is able to enhance the early germinal center reaction, further studies to understand how to target the germinal center and CD4+ T cells specifically to increase long-lived antiviral humoral immunity are needed.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11404825/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142299230","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":"Microglia and macrophages alterations in the CNS during acute SIV infection: A single-cell analysis in rhesus macaques.","authors":"Xiaoke Xu, Meng Niu, Benjamin G Lamberty, Katy Emanuel, Shawn Ramachandran, Andrew J Trease, Mehnaz Tabassum, Jeffrey D Lifson, Howard S Fox","doi":"10.1371/journal.ppat.1012168","DOIUrl":"10.1371/journal.ppat.1012168","url":null,"abstract":"<p><p>Human Immunodeficiency Virus (HIV) is widely acknowledged for its profound impact on the immune system. Although HIV primarily affects peripheral CD4 T cells, its influence on the central nervous system (CNS) cannot be overlooked. Within the brain, microglia and CNS-associated macrophages (CAMs) serve as the primary targets for HIV and the simian immunodeficiency virus (SIV) in nonhuman primates. This infection can lead to neurological effects and establish a viral reservoir. Given the gaps in our understanding of how these cells respond in vivo to acute CNS infection, we conducted single-cell RNA sequencing (scRNA-seq) on myeloid cells from the brains of three rhesus macaques 12 days after SIV infection, along with three uninfected controls. Our analysis revealed six distinct microglial clusters including homeostatic microglia, preactivated microglia, and activated microglia expressing high levels of inflammatory and disease-related molecules. In response to acute SIV infection, the homeostatic and preactivated microglia population decreased, while the activated and disease-related microglia increased. All microglial clusters exhibited upregulation of MHC class I molecules and interferon-related genes, indicating their crucial roles in defending against SIV during the acute phase. All microglia clusters also upregulated genes linked to cellular senescence. Additionally, we identified two distinct CAM populations: CD14lowCD16hi and CD14hiCD16low CAMs. Interestingly, during acute SIV infection, the dominant CAM population changed to one with an inflammatory phenotype. Specific upregulated genes within one microglia and one macrophage cluster were associated with neurodegenerative pathways, suggesting potential links to neurocognitive disorders. This research sheds light on the intricate interactions between viral infection, innate immune responses, and the CNS, providing valuable insights for future investigations.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11426456/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142299244","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}