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Armbruster KM, Jiang J, Sartorio MG, Scott NE, Peterson JM, Sexton JZ, Feldman MF, Koropatkin NM. Identification and Characterization of the Lipoprotein N-acyltransferase in Bacteroides. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.31.596883. [PMID: 38853980 PMCID: PMC11160734 DOI: 10.1101/2024.05.31.596883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Members of the Bacteroidota compose a large portion of the human gut microbiota, contributing to overall gut health via the degradation of various polysaccharides. This process is facilitated by lipoproteins, globular proteins anchored to the cell surface by a lipidated N-terminal cysteine. Despite their importance, lipoprotein synthesis by these bacteria is understudied. In E. coli, the α-amino linked lipid of lipoproteins is added by the lipoprotein N-acyltransferase Lnt. Herein, we have identified a protein distinct from Lnt responsible for the same process in Bacteroides, named lipoprotein N-acyltransferase in Bacteroides (Lnb). Deletion of Lnb yields cells that synthesize diacylated lipoproteins, with impacts on cell viability and morphology, growth on polysaccharides, and protein composition of membranes and outer membrane vesicles (OMVs). Our results not only challenge the accepted paradigms of lipoprotein biosynthesis in Gram-negative bacteria, but also support the establishment of a new family of lipoprotein N-acyltransferases.
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Affiliation(s)
- Krista M Armbruster
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Jiawen Jiang
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Mariana G Sartorio
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Nichollas E Scott
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, Victoria, 3000, Australia
| | - Jenna M Peterson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Jonathan Z Sexton
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Mario F Feldman
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
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Rahman NAA, Fuaad AAHA, Azami NAM, Amin MCIM, Azmi F. Next-generation Dengue Vaccines: Leveraging Peptide-Based Immunogens and Advanced Nanoparticles as Delivery Platforms. J Pharm Sci 2024:S0022-3549(24)00184-9. [PMID: 38761864 DOI: 10.1016/j.xphs.2024.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/13/2024] [Accepted: 05/13/2024] [Indexed: 05/20/2024]
Abstract
Dengue, caused by the dengue virus (DENV), is a prevalent arthropod-borne disease in humans and poses a significant burden on public health. Severe cases of dengue can be life-threatening. Although a licensed dengue vaccine is available, its efficacy varies across different virus serotypes and may exacerbate the disease in some seronegative recipients. Developing a safe and effective vaccine against all DENV serotypes remains challenging and requires continued research. Conventional approaches in dengue vaccine development, using live or attenuated microorganisms or parts of them often contain unnecessary epitopes, risking allergenic or autoimmune reactions. To address these challenges, innovative strategies such as peptide vaccines have been explored. Peptide vaccines offer a safer alternative by inducing specific immune responses with minimal immunogenic fragments. Chemical modification strategies of peptides have revolutionized their design, allowing for the incorporation of multi-epitope presentation, self-adjuvanting features, and self-assembling properties. These modifications enhance the antigenicity of the peptides, leading to improved vaccine efficacy. This review outlines advancements in peptide-based dengue vaccine development, leveraging nanoparticles as antigen-displaying platforms. Additionally, key immunological considerations for enhancing efficacy and safety against DENV infection have been addressed, providing insight into the next-generation of dengue vaccine development leveraging on peptide-nanoparticle technology.
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Affiliation(s)
- Nur Adilah Abdul Rahman
- Centre for Drug Delivery Technology and Vaccine (CENTRIC), Faculty of Pharmacy, Universiti Kebangsaan Malaysia, 50300 Kuala Lumpur, Federal Territory of Kuala Lumpur, Malaysia
| | - Abdullah Al-Hadi Ahmad Fuaad
- Department of Chemistry, Faculty of Science, Universiti Malaya, 50603 Kuala Lumpur, Federal Territory of Kuala Lumpur, Malaysia
| | - Nor Azila Muhammad Azami
- UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia, 56000 Cheras, Federal Territory of Kuala Lumpur, Malaysia
| | - Mohd Cairul Iqbal Mohd Amin
- Centre for Drug Delivery Technology and Vaccine (CENTRIC), Faculty of Pharmacy, Universiti Kebangsaan Malaysia, 50300 Kuala Lumpur, Federal Territory of Kuala Lumpur, Malaysia
| | - Fazren Azmi
- Centre for Drug Delivery Technology and Vaccine (CENTRIC), Faculty of Pharmacy, Universiti Kebangsaan Malaysia, 50300 Kuala Lumpur, Federal Territory of Kuala Lumpur, Malaysia.
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Wang X, Lee JC. Staphylococcus aureus membrane vesicles: an evolving story. Trends Microbiol 2024:S0966-842X(24)00088-X. [PMID: 38677977 DOI: 10.1016/j.tim.2024.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/29/2024]
Abstract
Staphylococcus aureus is an important bacterial pathogen that causes a wide variety of human diseases in community and hospital settings. S. aureus employs a diverse array of virulence factors, both surface-associated and secreted, to promote colonization, infection, and immune evasion. Over the past decade, a growing body of research has shown that S. aureus generates extracellular membrane vesicles (MVs) that package a variety of bacterial components, many of which are virulence factors. In this review, we summarize recent advances in our understanding of S. aureus MVs and highlight their biogenesis, cargo, and potential role in the pathogenesis of staphylococcal infections. Lastly, we present some emerging questions in the field.
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Affiliation(s)
- Xiaogang Wang
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA.
| | - Jean C Lee
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA
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Lou K, Chi J, Wu J, Ma J, Liu S, Cui Y. Research progress on the microbiota in bladder cancer tumors. Front Cell Infect Microbiol 2024; 14:1374944. [PMID: 38650736 PMCID: PMC11033431 DOI: 10.3389/fcimb.2024.1374944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 03/26/2024] [Indexed: 04/25/2024] Open
Abstract
The microbiota, also referred to as the microbial community, is a crucial component of the human microenvironment. It is located predominantly in various organs, including the intestines, skin, oral cavity, respiratory tract, and reproductive tract. The microbiota maintains a symbiotic relationship with the human body, influencing physiological and pathological functions to a significant degree. There is increasing evidence linking the microbial flora to human cancers. In contrast to the traditional belief that the urethra and urine of normal individuals are sterile, recent advancements in high-throughput sequencing technology and bacterial cultivation methods have led to the discovery of specific microbial communities in the urethras of healthy individuals. Given the prevalence of bladder cancer (BCa) as a common malignancy of the urinary system, researchers have shifted their focus to exploring the connection between disease development and the unique microbial community within tumors. This shift has led to a deeper investigation into the role of microbiota in the onset, progression, metastasis, prognosis, and potential for early detection of BCa. This article reviews the existing research on the microbiota within BCa tumors and summarizes the findings regarding the roles of different microbes in various aspects of this disease.
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Affiliation(s)
- Keyuan Lou
- Department of Urology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Junpeng Chi
- Department of Urology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Jitao Wu
- Department of Urology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Jian Ma
- Department of Urology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Shu Liu
- Department of Medical Oncology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Yuanshan Cui
- Department of Urology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
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Narayanan S, Baburajan AP, Muhammad M, Joseph A, Vemula PK, Bhat SG. Demonstrating the immunostimulatory and cytokine-augmentation effects of bacterial ghosts on natural killer cells and Caenorhabditis Elegans. Biotechnol Bioeng 2024; 121:959-970. [PMID: 38059432 PMCID: PMC7615764 DOI: 10.1002/bit.28619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/06/2023] [Accepted: 11/27/2023] [Indexed: 12/08/2023]
Abstract
The potential of bacteria-based immunotherapy lies in its ability to inherently enhance immune responses. However, the "liveness" of bacteria poses risks of bacterial escape, nonspecific immuno-stimulation, and ethical concerns, limiting their acceptability in immunotherapy. In this scenario, nonliving empty bacterial-cell envelopes, named bacterial ghosts (BGs), have emerged as immuno-stimulants with the potential to side-step the limitations of live bacterial therapies. This study demonstrates the capability of BGs in modulating the functionality of NK-92 cells and Caenorhabditis elegans (C. elegans), as well as perform as cytokine-therapy adjuvants. BGs were obtained through a pH-driven culture method, and were validated for their structural and chemical integrity via electron microscopy and spectroscopy. In NK-92 cells, BGs have shown significant immuno-stimulation by boosting the gene-expression of perforin, granzyme-B, Fas-L, and interferon-gamma by factors of 3.5-, 1.5-, 12.5-, and 8.6-folds, respectively. Combined BG and IL-12 treatment yielded a notable 10.2-fold increase in interferon-gamma protein expression in 24 h. The BGs also significantly influenced the innate immune response in C. elegans through the upregulation of lysozyme genes viz., ilys-3 (8.8-fold) and lys-2 (3.1-fold). Our investigation into the impact of BGs on natural killer cells and C. elegans highlights its potential as a valid alternative approach for new-age immunotherapy and cytokine augmentation.
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Affiliation(s)
- Sreeja Narayanan
- Department of Biotechnology, Cochin University of Science and Technology, Kochi, Kerala, India
| | | | - Mumtaz Muhammad
- Department of Biotechnology, Cochin University of Science and Technology, Kochi, Kerala, India
| | - Andrea Joseph
- Department of Biotechnology, Cochin University of Science and Technology, Kochi, Kerala, India
| | - Praveen Kumar Vemula
- Chemical Biology Approaches for Stem Cells and Therapeutics, Institute for Stem Cell Science and Regenerative Medicine (inStem), Bengaluru, Karnataka, India
| | - Sarita Ganapathy Bhat
- Department of Biotechnology, Cochin University of Science and Technology, Kochi, Kerala, India
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Jin T. Exploring the role of bacterial virulence factors and host elements in septic arthritis: insights from animal models for innovative therapies. Front Microbiol 2024; 15:1356982. [PMID: 38410388 PMCID: PMC10895065 DOI: 10.3389/fmicb.2024.1356982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 01/18/2024] [Indexed: 02/28/2024] Open
Abstract
Septic arthritis, characterized as one of the most aggressive joint diseases, is primarily attributed to Staphylococcus aureus (S. aureus) and often results from hematogenous dissemination. Even with prompt treatment, septic arthritis frequently inflicts irreversible joint damage, leading to sustained joint dysfunction in a significant proportion of patients. Despite the unsatisfactory outcomes, current therapeutic approaches for septic arthritis have remained stagnant for decades. In the clinical context, devising innovative strategies to mitigate joint damage necessitates a profound comprehension of the pivotal disease mechanisms. This entails unraveling how bacterial virulence factors interact with host elements to facilitate bacterial invasion into the joint and identifying the principal drivers of joint damage. Leveraging animal models of septic arthritis emerges as a potent tool to achieve these objectives. This review provides a comprehensive overview of the historical evolution and recent advancements in septic arthritis models. Additionally, we address practical considerations regarding experimental protocols. Furthermore, we delve into the utility of these animal models, such as their contribution to the discovery of novel bacterial virulence factors and host elements that play pivotal roles in the initiation and progression of septic arthritis. Finally, we summarize the latest developments in novel therapeutic strategies against septic arthritis, leveraging insights gained from these unique animal models.
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Affiliation(s)
- Tao Jin
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Rheumatology, Sahlgrenska University Hospital, Gothenburg, Sweden
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Schilcher K, Severn MM, Jenul C, Avina YSC, Keogh RA, Horswill AR. The Staphylococcus aureus CamS lipoprotein is a repressor of toxin production that shapes host-pathogen interaction. PLoS Biol 2024; 22:e3002451. [PMID: 38180978 PMCID: PMC10769083 DOI: 10.1371/journal.pbio.3002451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/27/2023] [Indexed: 01/07/2024] Open
Abstract
Lipoproteins of the opportunistic pathogen Staphylococcus aureus play a crucial role in various cellular processes and host interactions. Consisting of a protein and a lipid moiety, they support nutrient acquisition and anchor the protein to the bacterial membrane. Recently, we identified several processed and secreted small linear peptides that derive from the secretion signal sequence of S. aureus lipoproteins. Here, we show, for the first time, that the protein moiety of the S. aureus lipoprotein CamS has a biological role that is distinct from its associated linear peptide staph-cAM373. The small peptide was shown to be involved in interspecies horizontal gene transfer, the primary mechanism for the dissemination of antibiotic resistance among bacteria. We provide evidence that the CamS protein moiety is a potent repressor of cytotoxins, such as α-toxin and leukocidins. The CamS-mediated suppression of toxin transcription was reflected by altered disease severity in in vivo infection models involving skin and soft tissue, as well as bloodstream infections. Collectively, we have uncovered the role of the protein moiety of the staphylococcal lipoprotein CamS as a previously uncharacterized repressor of S. aureus toxin production, which consequently regulates virulence and disease outcomes. Notably, the camS gene is conserved in S. aureus, and we also demonstrated the muted transcriptional response of cytotoxins in 2 different S. aureus lineages. Our findings provide the first evidence of distinct biological functions of the protein moiety and its associated linear peptide for a specific lipoprotein. Therefore, lipoproteins in S. aureus consist of 3 functional components: a lipid moiety, a protein moiety, and a small linear peptide, with putative different biological roles that might not only determine the outcome of host-pathogen interactions but also drive the acquisition of antibiotic resistance determinants.
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Affiliation(s)
- Katrin Schilcher
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Morgan M. Severn
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Christian Jenul
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Young-Saeng C. Avina
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Rebecca A. Keogh
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
- Department of Veterans Affairs, Eastern Colorado Health Care System, Aurora, Colorado, United States of America
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Wang K, Cai X, Rao Y, Liu L, Hu Z, Peng H, Wang Y, Yang Y, Rao X, Nie K, Shang W. GehB Inactivates Lipoproteins to Delay the Healing of Acute Wounds Infected with Staphylococcus aureus. Curr Microbiol 2023; 81:36. [PMID: 38063939 DOI: 10.1007/s00284-023-03550-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 11/01/2023] [Indexed: 12/18/2023]
Abstract
Staphylococcus aureus is one of the most prevalent bacteria found in acute wounds. S. aureus produces many virulence factors and extracellular enzymes that contribute to bacterial survival, dissemination, and pathogenicity. Lipase GehB is a glycerol ester hydrolase that hydrolyzes triglycerides to facilitate the evasion of S. aureus from host immune recognition. However, the role and mechanism of lipase GehB in skin acute wound healing after S. aureus infection remain unclear. In this study, we found that the gehB gene deletion mutant (USA300ΔgehB) stimulated significantly higher levels of pro-inflammatory cytokines in RAW264.7 and Toll-like receptor 2 (TLR2)-transfected HEK293 cells than the wild-type USA300 strain did. Recombinant GehB-His treated lipoprotein (Lpp) reduced stimulation of TLR2-dependent TNF-α production by RAW264.7 macrophages. GehB delayed the skin acute wound healing in BALB/c mice infected with S. aureus, while wound healing was similar in C57BL/6 TLR2-/- mice infected with either wild-type USA300 or USA300ΔgehB. In BALB/c mice, we also observed more bacterial survival, less leukocyte recruitment, lower IL-8 production, and adipocyte differentiation in USA300-infected skin acute wound tissues than those in USA300ΔgehB-challenged ones. Our data indicated that GehB inactivates lipoproteins to shield S. aureus from innate immune killing, resulting in delayed the healing of skin acute wounds infected with S. aureus.
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Affiliation(s)
- Kaiyu Wang
- Department of Plastic Surgery and Burns, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, China
- The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, 563003, China
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Xinyu Cai
- Department of Emergency Medicine, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China
| | - Yifan Rao
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, 400038, China
- Department of Emergency Medicine, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China
| | - Lu Liu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, 400038, China
- Department of Microbiology, School of Medicine, Chongqing University, Chongqing, 400044, China
| | - Zhen Hu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Huagang Peng
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Yuting Wang
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Yi Yang
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Kaiyu Nie
- Department of Plastic Surgery and Burns, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, China.
- The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, 563003, China.
| | - Weilong Shang
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, 400038, China.
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Yu FY, Zheng K, Wu YF, Gao SW, Weng QY, Zhu C, Wu YP, Li M, Qin ZN, Lou JF, Chen ZH, Ying SM, Shen HH, Li W. Rapamycin Exacerbates Staphylococcus aureus Pneumonia by Inhibiting mTOR-RPS6 in Macrophages. J Inflamm Res 2023; 16:5715-5728. [PMID: 38053607 PMCID: PMC10695130 DOI: 10.2147/jir.s434483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 11/17/2023] [Indexed: 12/07/2023] Open
Abstract
Purpose This study aimed to explore the effect of Rapamycin (Rapa) in Staphylococcus aureus (S. aureus) pneumonia and clarify its possible mechanism. Methods We investigated the effects of Rapa on S. aureus pneumonia in mouse models and in macrophages cultured in vitro. Two possible mechanisms were investigated: the mTOR-RPS6 pathway phosphorylation and phagocytosis. Furthermore, for the mechanism verification in vivo, mice with specific Mtor knockout in myeloid cells were constructed for pneumonia models. Results Rapa exacerbated S. aureus pneumonia in mouse models, promoting chemokines secretion and inflammatory cells infiltration in lung. In vitro, Rapa upregulated the secretion of chemokines and cytokines in macrophages induced by S. aureus. Mechanistically, the mTOR-ribosomal protein S6 (RPS6) pathway in macrophages was phosphorylated in response to S. aureus infection, and the inhibition of RPS6 phosphorylation upregulated the inflammation level. However, Rapa did not increase the phagocytic activity. Accordingly, mice with specific Mtor knockout in myeloid cells experienced more severe S. aureus pneumonia. Conclusion Rapa exacerbates S. aureus pneumonia by increasing the inflammatory levels of macrophages. Inhibition of mTOR-RPS6 pathway upregulates the expression of cytokines and chemokines in macrophages, thus increases inflammatory cells infiltration and exacerbates tissue damage.
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Affiliation(s)
- Fang-Yi Yu
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Kua Zheng
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Yin-Fang Wu
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Shen-Wei Gao
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Qing-Yu Weng
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Chen Zhu
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Yan-Ping Wu
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Miao Li
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Zhong-Nan Qin
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Jia-Fei Lou
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Zhi-Hua Chen
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Song-Min Ying
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Hua-Hao Shen
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Wen Li
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
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Zymovets V, Rakhimova O, Wadelius P, Schmidt A, Brundin M, Kelk P, Landström M, Vestman NR. Exploring the impact of oral bacteria remnants on stem cells from the Apical papilla: mineralization potential and inflammatory response. Front Cell Infect Microbiol 2023; 13:1257433. [PMID: 38089810 PMCID: PMC10711090 DOI: 10.3389/fcimb.2023.1257433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 11/08/2023] [Indexed: 12/18/2023] Open
Abstract
Introduction Bacterial persistence is considered one of the main causal factors for regenerative endodontic treatment (RET) failure in immature permanent teeth. This interference is claimed to be caused by the interaction of bacteria that reside in the root canal with the stem cells that are one of the essentials for RET. The aim of the study was to investigate whether prolonged exposure of stem cells from the apical papilla (SCAP) to bacterial remnants of Fusobacterium nucleatum, Actinomyces gerensceriae, Slackia exigua, Enterococcus faecalis, Peptostreptococcaceae yurii, commonly found in infected traumatized root canals, and the probiotic bacteria Lactobacillus gasseri and Limosilactobacillus reuteri, can alter SCAP's inflammatory response and mineralization potential. Methods To assess the effect of bacterial remnants on SCAP, we used UV-C-inactivated bacteria (as cell wall-associated virulence factors) and bacterial DNA. Histochemical staining using Osteoimage Mineralization Assay and Alizarin Red analysis was performed to study SCAP mineralization, while inflammatory and osteo/odontogenic-related responses of SCAPs were assessed with Multiplex ELISA. Results We showed that mineralization promotion was greater with UV C-inactivated bacteria compared to bacterial DNA. Immunofluorescence analysis detected that the early mineralization marker alkaline phosphatase (ALP) was increased by the level of E. coli lipopolysaccharide (LPS) positive control in the case of UV-C-inactivated bacteria; meanwhile, DNA treatment decreased the level of ALP compared to the positive control. SCAP's secretome assessed with Multiplex ELISA showed the upregulation of pro-inflammatory factors IL-6, IL-8, GM-CSF, IL-1b, neurotrophic factor BDNF, and angiogenic factor VEGF, induced by UV-C-killed bacteria. Discussion The results suggest that long term stimulation (for 21 days) of SCAP with UV-C-inactivated bacteria stimulate their mineralization and inflammatory response, while DNA influence has no such effect, which opens up new ideas about the nature of RET failure.
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Affiliation(s)
| | | | - Philip Wadelius
- Department of Endodontics, Region of Västerbotten, Umeå, Sweden
| | - Alexej Schmidt
- Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden
| | - Malin Brundin
- Department of Odontology, Umeå University, Umeå, Sweden
| | - Peyman Kelk
- Section for Anatomy, Department of Integrative Medical Biology (IMB), Umeå University, Umeå, Sweden
| | - Maréne Landström
- Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden
| | - Nelly Romani Vestman
- Department of Odontology, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
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11
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Gupta R, Singh M, Pathania R. Chemical genetic approaches for the discovery of bacterial cell wall inhibitors. RSC Med Chem 2023; 14:2125-2154. [PMID: 37974958 PMCID: PMC10650376 DOI: 10.1039/d3md00143a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 08/10/2023] [Indexed: 11/19/2023] Open
Abstract
Antimicrobial resistance (AMR) in bacterial pathogens is a worldwide health issue. The innovation gap in discovering new antibiotics has remained a significant hurdle in combating the AMR problem. Currently, antibiotics target various vital components of the bacterial cell envelope, nucleic acid and protein biosynthesis machinery and metabolic pathways essential for bacterial survival. The critical role of the bacterial cell envelope in cell morphogenesis and integrity makes it an attractive drug target. While a significant number of in-clinic antibiotics target peptidoglycan biosynthesis, several components of the bacterial cell envelope have been overlooked. This review focuses on various antibacterial targets in the bacterial cell wall and the strategies employed to find their novel inhibitors. This review will further elaborate on combining forward and reverse chemical genetic approaches to discover antibacterials that target the bacterial cell envelope.
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Affiliation(s)
- Rinki Gupta
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee Roorkee - 247 667 Uttarakhand India
| | - Mangal Singh
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee Roorkee - 247 667 Uttarakhand India
| | - Ranjana Pathania
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee Roorkee - 247 667 Uttarakhand India
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12
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Payen S, Roy D, Okura M, Segura M, Gottschalk M. Study of the Role of Lipoprotein Maturation Enzymes in the Pathogenesis of the Infection Caused by the Streptococcus suis Serotype 2 Sequence Type 25 North American Prototype Strain. Pathogens 2023; 12:1325. [PMID: 38003790 PMCID: PMC10675726 DOI: 10.3390/pathogens12111325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 11/26/2023] Open
Abstract
Streptococcus suis serotype 2 is an important swine bacterial pathogen causing sudden death, septic shock, and meningitis. However, serotype 2 strains are phenotypically and genotypically heterogeneous and composed of a multitude of sequence types (STs) whose distributions greatly vary worldwide. It has been previously shown that the lipoprotein (LPP) maturation enzymes diacylglyceryl transferase (Lgt) and signal peptidase (Lsp) significantly modulate the inflammatory host response and play a differential role in virulence depending on the genetic background of the strain. Differently from Eurasian ST1/ST7 strains, the capsular polysaccharide of a North American S. suis serotype 2 ST25 representative strain only partially masks sub-capsular domains and bacterial wall components. Thus, our hypothesis is that since LPPs would be more surface exposed in ST25 strains than in their ST1 or ST7 counterparts, the maturation enzymes would play a more important role in the pathogenesis of the infection caused by the North American strain. Using isogenic Δlgt and Δlsp mutants derived from the wild-type ST25 strain, our studies suggest that these enzymes do not seem to play a role in the interaction between S. suis and epithelial and endothelial cells, regardless of the genetics background of the strain used. However, a role in the formation of biofilms (also independently of the STs) has been demonstrated. Moreover, the involvement of LPP dendritic cell activation in vitro seems to be somehow more pronounced with the ST25 strain. Finally, the Lgt enzyme seems to play a more important role in the virulence of the ST25 strain. Although some differences between STs could be observed, our original hypothesis that LPPs would be significantly more important in ST25 strains due to a better bacterial surface exposition could not be confirmed.
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Affiliation(s)
- Servane Payen
- Groupe de Recherche sur les Maladies Infectieuses en Production Animale (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC J2S 2M2, Canada; (S.P.); (M.S.)
| | - David Roy
- Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada;
| | - Masatoshi Okura
- Division of Transboundary Animal Disease Research, National Institute of Animal Health, National Agriculture and Food Research Organization, Kagoshima 891-0105, Japan;
| | - Mariela Segura
- Groupe de Recherche sur les Maladies Infectieuses en Production Animale (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC J2S 2M2, Canada; (S.P.); (M.S.)
| | - Marcelo Gottschalk
- Groupe de Recherche sur les Maladies Infectieuses en Production Animale (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC J2S 2M2, Canada; (S.P.); (M.S.)
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13
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Hurley MJ, Menozzi E, Koletsi S, Bates R, Gegg ME, Chau KY, Blottière HM, Macnaughtan J, Schapira AHV. α-Synuclein expression in response to bacterial ligands and metabolites in gut enteroendocrine cells: an in vitro proof of concept study. Brain Commun 2023; 5:fcad285. [PMID: 37953845 PMCID: PMC10636561 DOI: 10.1093/braincomms/fcad285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 09/03/2023] [Accepted: 10/23/2023] [Indexed: 11/14/2023] Open
Abstract
Caudo-rostral migration of pathological forms of α-synuclein from the gut to the brain is proposed as an early feature in Parkinson's disease pathogenesis, but the underlying mechanisms remain unknown. Intestinal epithelial enteroendocrine cells sense and respond to numerous luminal signals, including bacterial factors, and transmit this information to the brain via the enteric nervous system and vagus nerve. There is evidence that gut bacteria composition and their metabolites change in Parkinson's disease patients, and these alterations can trigger α-synuclein pathology in animal models of the disorder. Here, we investigated the effect of toll-like receptor and free fatty acid receptor agonists on the intracellular level of α-synuclein and its release using mouse secretin tumour cell line 1 enteroendocrine cells. Secretin tumour cell line 1 enteroendocrine cells were treated for 24 or 48 h with toll-like receptor agonists (toll-like receptor 4 selective lipopolysaccharide; toll-like receptor 2 selective Pam3CysSerLys4) and the free fatty acid receptor 2/3 agonists butyrate, propionate and acetate. The effect of selective receptor antagonists on the agonists' effects after 24 hours was also investigated. The level of α-synuclein protein was measured in cell lysates and cell culture media by western blot and enzyme-linked immunosorbent assay. The level of α-synuclein and tumour necrosis factor messenger RNA was measured by quantitative reverse transcription real-time polymerase chain reaction. Stimulation of secretin tumour cell line 1 enteroendocrine cells for 24 and 48 hours with toll-like receptor and free fatty acid receptor agonists significantly increased the amount of intracellular α-synuclein and the release of α-synuclein from the cells into the culture medium. Both effects were significantly reduced by antagonists selective for each receptor. Toll-like receptor and free fatty acid receptor agonists also significantly increased tumour necrosis factor transcription, and this was effectively inhibited by corresponding antagonists. Elevated intracellular α-synuclein increases the likelihood of aggregation and conversion to toxic forms. Factors derived from bacteria induce α-synuclein accumulation in secretin tumour cell line 1 enteroendocrine cells. Here, we provide support for a mechanism by which exposure of enteroendocrine cells to specific bacterial factors found in Parkinson's disease gut dysbiosis might facilitate accumulation of α-synuclein pathology in the gut.
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Affiliation(s)
- Michael J Hurley
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London NW3 2PF, UK
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Elisa Menozzi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London NW3 2PF, UK
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Sofia Koletsi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London NW3 2PF, UK
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Rachel Bates
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London NW3 2PF, UK
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Matthew E Gegg
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London NW3 2PF, UK
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Kai-Yin Chau
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London NW3 2PF, UK
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Hervé M Blottière
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Université Paris-Saclay, INRAE, MetaGenoPolis, Jouy en Josas, & Nantes Université, INRAE, UMR 1280 PhAN, Nantes 44093, France
| | - Jane Macnaughtan
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London NW3 2PF, UK
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Institute for Liver and Digestive Health, University College London, London NW3 2PF, UK
| | - Anthony H V Schapira
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London NW3 2PF, UK
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
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14
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Ye X, Wang J, Xu P, Yang X, Shi Q, Liu G, Bai Z, Zhou C, Ma L. Peptide MSI-1 inhibited MCR-1 and regulated outer membrane vesicles to combat immune evasion of Escherichia coli. Microb Biotechnol 2023; 16:1755-1773. [PMID: 37329166 PMCID: PMC10443334 DOI: 10.1111/1751-7915.14297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/02/2023] [Accepted: 06/05/2023] [Indexed: 06/18/2023] Open
Abstract
Polymyxin resistance is conferred by MCR-1 (mobile colistin resistance 1)-induced lipopolysaccharide (LPS) modification of G- bacteria. However, the peptide MSI-1 exerts potent antimicrobial activity against mcr-1-carrying bacteria. To further investigate the potential role of MCR-1 in improving bacterial virulence and facilitating immune evasion, and the immunomodulatory effect of peptide MSI-1, we first explored outer membrane vesicle (OMV) alterations of mcr-1-carrying bacteria in the presence and absence of sub-MIC MSI-1, and host immune activation during bacterial infection and OMV stimulation. Our results demonstrated that LPS remodelling induced by MCR-1 negatively affected OMV formation and protein cargo by E. coli. In addition, MCR-1 diminished LPS-stimulated pyroptosis but facilitated mitochondrial dysfunction, further aggravating apoptosis in macrophages induced by OMVs of E. coli. Similarly, TLR4-mediated NF-κB activation was markedly alleviated once LPS was modified by MCR-1. However, peptide MSI-1 at the sub-MIC level inhibited the expression of MCR-1, further partly rescuing OMV alteration and attenuation of immune responses in the presence of MCR-1 during both infection and OMV stimulation, which can be exploited for anti-infective therapy.
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Affiliation(s)
- Xinyue Ye
- School of Life Science and TechnologyChina Pharmaceutical UniversityNanjingJiangsuChina
| | - Jian Wang
- School of Life Science and TechnologyChina Pharmaceutical UniversityNanjingJiangsuChina
| | - Pengfei Xu
- School of Life Science and TechnologyChina Pharmaceutical UniversityNanjingJiangsuChina
| | - Xiaoqian Yang
- School of Life Science and TechnologyChina Pharmaceutical UniversityNanjingJiangsuChina
| | - Qixue Shi
- School of Life Science and TechnologyChina Pharmaceutical UniversityNanjingJiangsuChina
| | - Genyan Liu
- Department of Laboratory MedicineFirst Affiliated Hospital of Nanjing Medical UniversityNanjingJiangsuChina
| | - Zhaoshi Bai
- Jiangsu Cancer Hospital, Jiangsu Institute of Cancer ResearchThe Affiliated Cancer Hospital of Nanjing Medical UniversityNanjingJiangsuChina
| | - Changlin Zhou
- School of Life Science and TechnologyChina Pharmaceutical UniversityNanjingJiangsuChina
| | - Lingman Ma
- School of Life Science and TechnologyChina Pharmaceutical UniversityNanjingJiangsuChina
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15
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Wang J, Sheng Z, Liu Y, Chen X, Wang S, Yang H. Combined proteomic and transcriptomic analysis of the antimicrobial mechanism of tannic acid against Staphylococcus aureus. Front Pharmacol 2023; 14:1178177. [PMID: 37654613 PMCID: PMC10466393 DOI: 10.3389/fphar.2023.1178177] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 08/01/2023] [Indexed: 09/02/2023] Open
Abstract
Staphylococcus aureus is a zoonotic opportunistic pathogen that represents a significant threat to public health. Previous studies have shown that tannic acid (TA) has an inhibitory effect on a variety of bacteria. In this study, the proteome and transcriptome of S. aureus were analyzed to comprehensively assess changes in genes and proteins induced by TA. Initial observations of morphological changes revealed that TA damaged the integrity of the cell membrane. Next, proteomic and genetic analyses showed that exposure to TA altered the expression levels of 651 differentially expressed proteins (DEPs, 283 upregulated and 368 downregulated) and 503 differentially expressed genes (DEGs, 191 upregulated and 312 downregulated). Analysis of the identified DEPs and DEGs suggested that TA damages the integrity of the cell envelope by decreasing the expression and protein abundance of enzymes involved in the synthesis of peptidoglycans, teichoic acids and fatty acids, such as murB, murQ, murG, fmhX and tagA. After treatment with TA, the assembly of ribosomes in S. aureus was severely impaired by significant reductions in available ribosome components, and thus protein synthesis was hindered. The levels of genes and proteins associated with amino acids and purine synthesis were remarkably decreased, which further reduced bacterial viability. In addition, ABC transporters, which are involved in amino acid and ion transport, were also badly affected. Our results reveal the molecular mechanisms underlying the effects of TA on S. aureus and provide a theoretical basis for the application of TA as an antibacterial chemotherapeutic agent.
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Affiliation(s)
- Jing Wang
- Jiangsu Agri-Animal Husbandry Vocational College, Taizhou, Jiangsu Province, China
| | - Zhicun Sheng
- Jiangsu Agri-Animal Husbandry Vocational College, Taizhou, Jiangsu Province, China
| | - Yunying Liu
- Jiangsu Agri-Animal Husbandry Vocational College, Taizhou, Jiangsu Province, China
- Zhongchong Sino Biotech Taizhou Co., Ltd., Taizhou, Jiangsu Province, China
| | - Xiaolan Chen
- Jiangsu Agri-Animal Husbandry Vocational College, Taizhou, Jiangsu Province, China
| | - Shuaibing Wang
- Jiangsu Agri-Animal Husbandry Vocational College, Taizhou, Jiangsu Province, China
| | - Haifeng Yang
- Jiangsu Agri-Animal Husbandry Vocational College, Taizhou, Jiangsu Province, China
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16
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Kaur R, Mangiafesto J, Pryharski K, Rasam S, Zagursky R, Pichichero M. Expression conditions and characterization of a novelly constructed lipoprotein intended as a vaccine to prevent human Haemophilus influenzae infections. J Biol Chem 2023; 299:105031. [PMID: 37437888 PMCID: PMC10407732 DOI: 10.1016/j.jbc.2023.105031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 06/16/2023] [Accepted: 07/01/2023] [Indexed: 07/14/2023] Open
Abstract
Bacterial lipoproteins are structurally divided into two groups, based on their lipid moieties: diacylated (present in Gram-positive bacteria) and triacylated (present in some Gram-positive and most Gram-negative bacteria). Diacylated and triacylated lipid moieties differ by a single amide-linked fatty acid chain. Lipoproteins induce host innate immune responses by the mammalian Toll-like receptor 2 (TLR2). In this study, we added a lipid moiety to recombinant OMP26, a native nonlipidated (NL) membrane protein of Haemophilus influenzae, and characterized it extensively under different expression conditions using flow cytometry, LC/MS, and MALDI-TOF. We also investigated the ability of NL and lipidated (L) OMP26 to induce in vitro stimulation of HEK Blue-hTLR2-TR1 and hTLR-TLR6 cells. Our L-OMP26 was predominantly expressed in diacylated form, so we employed an additional gene copy of apolipoprotein N-acetyltransferase enzyme (Lnt)-rich Escherichia coli strain that further acylates the diacyl lipoproteins to enhance the production of triacylated L-OMP26. The diacyl and triacyl versions of L-OMP26, intended as a vaccine for use in humans, were characterized and evaluated as protein vaccine components in a mouse model. We found that the diacyl and triacyl L-OMP26 protein formulations differed markedly in their immune-stimulatory activity, with diacylated L-OMP26 stimulating higher adaptive immune responses compared with triacylated L-OMP26 and both stimulating higher adaptive immune response compared to NL-OMP26. We also constructed and characterized an L-OMP26φNL-P6 fusion protein, where NL-P6 protein (a commonly studied H. influenzae vaccine candidate) was recombinantly fused to L-OMP26. We observed a similar pattern of lipidation (predominantly diacylated) in the L-OMP26φNL-P6 fusion protein.
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Affiliation(s)
- Ravinder Kaur
- Center for Infectious Diseases and Immunology, Rochester General Hospital Research Institute, Rochester, New York, USA.
| | - Jill Mangiafesto
- Center for Infectious Diseases and Immunology, Rochester General Hospital Research Institute, Rochester, New York, USA
| | - Karin Pryharski
- Center for Infectious Diseases and Immunology, Rochester General Hospital Research Institute, Rochester, New York, USA
| | - Sailee Rasam
- Department of Biochemistry, State University of New York at Buffalo, New York, USA
| | - Robert Zagursky
- Center for Infectious Diseases and Immunology, Rochester General Hospital Research Institute, Rochester, New York, USA
| | - Michael Pichichero
- Center for Infectious Diseases and Immunology, Rochester General Hospital Research Institute, Rochester, New York, USA.
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17
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Patel H, Rawat S. A genetic regulatory see-saw of biofilm and virulence in MRSA pathogenesis. Front Microbiol 2023; 14:1204428. [PMID: 37434702 PMCID: PMC10332168 DOI: 10.3389/fmicb.2023.1204428] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 05/30/2023] [Indexed: 07/13/2023] Open
Abstract
Staphylococcus aureus is one of the most common opportunistic human pathogens causing several infectious diseases. Ever since the emergence of the first methicillin-resistant Staphylococcus aureus (MRSA) strain decades back, the organism has been a major cause of hospital-acquired infections (HA-MRSA). The spread of this pathogen across the community led to the emergence of a more virulent subtype of the strain, i.e., Community acquired Methicillin resistant Staphylococcus aureus (CA-MRSA). Hence, WHO has declared Staphylococcus aureus as a high-priority pathogen. MRSA pathogenesis is remarkable because of the ability of this "superbug" to form robust biofilm both in vivo and in vitro by the formation of polysaccharide intercellular adhesin (PIA), extracellular DNA (eDNA), wall teichoic acids (WTAs), and capsule (CP), which are major components that impart stability to a biofilm. On the other hand, secretion of a diverse array of virulence factors such as hemolysins, leukotoxins, enterotoxins, and Protein A regulated by agr and sae two-component systems (TCS) aids in combating host immune response. The up- and downregulation of adhesion genes involved in biofilm formation and genes responsible for synthesizing virulence factors during different stages of infection act as a genetic regulatory see-saw in the pathogenesis of MRSA. This review provides insight into the evolution and pathogenesis of MRSA infections with a focus on genetic regulation of biofilm formation and virulence factors secretion.
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Affiliation(s)
| | - Seema Rawat
- Microbiology Laboratory, School of Life Sciences, Central University of Gujarat, Gandhinagar, Gujarat, India
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18
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Nguyen MT, Hu Z, Mohammad M, Schöttler H, Niemann S, Schultz M, Barczyk-Kahlert K, Jin T, Hayen H, Herrmann M. Bacterial Lipoproteins Shift Cellular Metabolism to Glycolysis in Macrophages Causing Bone Erosion. Microbiol Spectr 2023; 11:e0429322. [PMID: 37191536 PMCID: PMC10269925 DOI: 10.1128/spectrum.04293-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 04/25/2023] [Indexed: 05/17/2023] Open
Abstract
Belonging to a group of membrane proteins, bacterial lipoproteins (LPPs) are defined by a unique lipid structure at their N-terminus providing the anchor in the bacterial cell membrane. In Gram-positive bacteria, LPPs play a key role in host immune activation triggered through a Toll-like receptor 2 (TLR2)-mediated action resulting in macrophage stimulation and subsequent tissue damage demonstrated in in vivo experimental models. Yet the physiologic links between LPP activation, cytokine release, and any underlying switches in cellular metabolism remain unclear. In this study, we demonstrate that Staphylococcus aureus Lpl1 not only triggers cytokine production but also confers a shift toward fermentative metabolism in bone marrow-derived macrophages (BMDMs). Lpl1 consists of di- and tri-acylated LPP variants; hence, the synthetic P2C and P3C, mimicking di-and tri-acylated LPPs, were employed to reveal their effect on BMDMs. Compared to P3C, P2C was found to shift the metabolism of BMDMs and the human mature monocytic MonoMac 6 (MM6) cells more profoundly toward the fermentative pathway, as indicated by lactate accumulation, glucose consumption, pH reduction, and oxygen consumption. In vivo, P2C caused more severe joint inflammation, bone erosion, and lactate and malate accumulation than P3C. These observed P2C effects were completely abrogated in monocyte/macrophage-depleted mice. Taken together, these findings now solidly confirm the hypothesized link between LPP exposure, a macrophage metabolic shift toward fermentation, and ensuing bone destruction. IMPORTANCE Osteomyelitis caused by S. aureus is a severe infection of the bone, typically associated with severe bone function impairment, therapeutic failure, high morbidity, invalidity, and occasionally even death. The hallmark of staphylococcal osteomyelitis is the destruction of the cortical bone structures, yet the mechanisms contributing to this pathology are hitherto poorly understood. One bacterial membrane constituent found in all bacteria is bacterial lipoproteins (LPPs). Previously, we have shown that injection of purified S. aureus LPPs into wild-type mouse knee joints caused a TLR2-dependent chronic destructive arthritis but failed to elicit such effect in monocyte/macrophage-depleted mice. This observation stirred our interest in investigating the interaction of LPPs and macrophages and analyzing the underlying physiological mechanisms. This ascertainment of LPP-induced changes in the physiology of macrophages provides an important clue in the understanding of the mechanisms of bone disintegration, opening novel avenues to manage the course of S. aureus disease.
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Affiliation(s)
- Minh-Thu Nguyen
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
| | - Zhicheng Hu
- Center for Clinical Laboratories, The Affiliated Hospital of Guizhou Medical University, Guiyang, China
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Majd Mohammad
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Hannah Schöttler
- Institute of Inorganic and Analytical Chemistry, University of Münster, Münster, Germany
| | - Silke Niemann
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
| | - Michelle Schultz
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | | | - Tao Jin
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Heiko Hayen
- Institute of Inorganic and Analytical Chemistry, University of Münster, Münster, Germany
| | - Mathias Herrmann
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
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19
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Jana B, Liu X, Dénéréaz J, Park H, Leshchiner D, Liu B, Gallay C, Veening JW, van Opijnen T. CRISPRi-TnSeq: A genome-wide high-throughput tool for bacterial essential-nonessential genetic interaction mapping. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.31.543074. [PMID: 37398100 PMCID: PMC10312587 DOI: 10.1101/2023.05.31.543074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Genetic interaction networks can help identify functional connections between genes and pathways, which can be leveraged to establish (new) gene function, drug targets, and fill pathway gaps. Since there is no optimal tool that can map genetic interactions across many different bacterial strains and species, we develop CRISPRi-TnSeq, a genome-wide tool that maps genetic interactions between essential genes and nonessential genes through the knockdown of a targeted essential gene (CRISPRi) and the simultaneous knockout of individual nonessential genes (Tn-Seq). CRISPRi-TnSeq thereby identifies, on a genome-wide scale, synthetic and suppressor-type relationships between essential and nonessential genes, enabling the construction of essential-nonessential genetic interaction networks. To develop and optimize CRISPRi-TnSeq, CRISPRi strains were obtained for 13 essential genes in Streptococcus pneumoniae, involved in different biological processes including metabolism, DNA replication, transcription, cell division and cell envelope synthesis. Transposon-mutant libraries were constructed in each strain enabling screening of ∼24,000 gene-gene pairs, which led to the identification of 1,334 genetic interactions, including 754 negative and 580 positive genetic interactions. Through extensive network analyses and validation experiments we identify a set of 17 pleiotropic genes, of which a subset tentatively functions as genetic capacitors, dampening phenotypic outcomes and protecting against perturbations. Furthermore, we focus on the relationships between cell wall synthesis, integrity and cell division and highlight: 1) how essential gene knockdown can be compensated by rerouting flux through nonessential genes in a pathway; 2) the existence of a delicate balance between Z-ring formation and localization, and septal and peripheral peptidoglycan (PG) synthesis to successfully accomplish cell division; 3) the control of c-di-AMP over intracellular K + and turgor, and thereby modulation of the cell wall synthesis machinery; 4) the dynamic nature of cell wall protein CozEb and its effect on PG synthesis, cell shape morphology and envelope integrity; 5) functional dependency between chromosome decatenation and segregation, and the critical link with cell division, and cell wall synthesis. Overall, we show that CRISPRi-TnSeq uncovers genetic interactions between closely functionally linked genes and pathways, as well as disparate genes and pathways, highlighting pathway dependencies and valuable leads for gene function. Importantly, since both CRISPRi and Tn-Seq are widely used tools, CRISPRi-TnSeq should be relatively easy to implement to construct genetic interaction networks across many different microbial strains and species.
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20
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A Copper-Responsive Two-Component System Governs Lipoprotein Remodeling in Listeria monocytogenes. J Bacteriol 2023; 205:e0039022. [PMID: 36622228 PMCID: PMC9879112 DOI: 10.1128/jb.00390-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Bacterial lipoproteins are membrane-associated proteins with a characteristic acylated N-terminal cysteine residue anchoring C-terminal globular domains to the membrane surface. While all lipoproteins are modified with acyl chains, the number, length, and position can vary depending on host. The acylation pattern also alters ligand recognition by the Toll-like receptor 2 (TLR2) protein family, a signaling system that is central to bacterial surveillance and innate immunity. In select Listeria monocytogenes isolates carrying certain plasmids, copper exposure converts the lipoprotein chemotype into a weak TLR2 ligand through expression of the enzyme lipoprotein intramolecular acyltransferase (Lit). In this study, we identify the response regulator (CopR) from a heavy metal-sensing two-component system as the transcription factor that integrates external copper levels with lipoprotein structural modifications. We show that phosphorylated CopR controls the expression of three distinct transcripts within the plasmid cassette encoding Lit2, prolipoprotein diacylglyceryl transferase (Lgt2), putative copper resistance determinants, and itself (the CopRS two-component system). CopR recognizes a direct repeat half-site consensus motif (TCTACACA) separated by 3 bp that overlaps the -35 promoter element. Target gene expression and lipoprotein conversion were not observed in the absence of the response regulator, indicating that CopR phosphorylation is the dominant mechanism of regulation. IMPORTANCE Copper is a frontline antimicrobial used to limit bacterial growth in multiple settings. Here, we demonstrate how the response regulator CopR from a plasmid-borne two-component system in the opportunistic pathogen L. monocytogenes directly induces lipoprotein remodeling in tandem with copper resistance genes due to extracellular copper stress. Activation of CopR by phosphorylation converts the lipoprotein chemotype from a high- to low-immunostimulatory TLR2 ligand. The two-component system-mediated coregulation of copper resistance determinants, in tandem with lipoprotein biosynthesis demonstrated here in L. monocytogenes, may be a common feature of transmissible copper resistance cassettes found in other Firmicutes.
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Karthikeyan R, Gayathri P, Ramasamy S, Suvekbala V, Jagannadham MV, Rajendhran J. Transcriptome responses of intestinal epithelial cells induced by membrane vesicles of Listeria monocytogenes. CURRENT RESEARCH IN MICROBIAL SCIENCES 2023; 4:100185. [PMID: 36942003 PMCID: PMC10023947 DOI: 10.1016/j.crmicr.2023.100185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023] Open
Abstract
Membrane vesicles (MVs) serve as an essential virulence factor in several pathogenic bacteria. The release of MVs by Listeria monocytogenes is only recently recognized; still, the enigmatic role of MVs in pathogenesis is yet to be established. We report the transcriptome response of Caco-2 cells upon exposure to MVs and the L. monocytogenes that leads to observe the up-regulation of autophagy-related genes in the early phase of exposure to MVs. Transcription of inflammatory cytokines is to the peak at the fourth hour of exposure. An array of differentially expressed genes was associated with actin cytoskeleton rearrangement, autophagy, cell cycle arrest, and induction of oxidative stress. At a later time point, transcriptional programs are generated upon interaction with MVs to evade innate immune signals, by modulating the expression of anti-inflammatory genes. KEGG pathway analysis is palpably confirming that MVs appear principally responsible for the induction of immune signaling pathways. Besides, MVs induced the expression of cell cycle regulatory genes, likely responsible for the ability to prolong host cell survival, thus protecting the replicative niche for L. monocytogenes. Notably, we identified several non-coding RNAs (ncRNAs), possibly involved in the regulation of early manipulation of the host gene expression, essential for the persistence of L. monocytogenes.
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Affiliation(s)
- Raman Karthikeyan
- Department of Genetics, School of Biological Sciences, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
| | - Pratapa Gayathri
- CSIR - Centre for Cellular and Molecular Biology, Tarnaka, Hyderabad 500007, India
| | - Subbiah Ramasamy
- Department of Biochemistry, School of Biological Sciences, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
| | - Vemparthan Suvekbala
- EDII-Anna Business Incubation Research Foundation, University College of Engineering, BIT Campus, Anna University, Tiruchirappalli 620024, India
| | - Medicharla V. Jagannadham
- CSIR - Centre for Cellular and Molecular Biology, Tarnaka, Hyderabad 500007, India
- Corresponding authors.
| | - Jeyaprakash Rajendhran
- Department of Genetics, School of Biological Sciences, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
- Corresponding authors.
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22
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Kuijk MM, Wu Y, van Hensbergen VP, Shanlitourk G, Payré C, Lambeau G, Man-Bovenkerk S, Herrmann J, Müller R, van Strijp JAG, Pannekoek Y, Touqui L, van Sorge NM. Interference with Lipoprotein Maturation Sensitizes Methicillin-Resistant Staphylococcus aureus to Human Group IIA-Secreted Phospholipase A2 and Daptomycin. J Innate Immun 2022; 15:333-350. [PMID: 36473432 PMCID: PMC10643906 DOI: 10.1159/000527549] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 10/11/2022] [Indexed: 11/17/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) has been classified as a high priority pathogen by the World Health Organization underlining the high demand for new therapeutics to treat infections. Human group IIA-secreted phospholipase A2 (hGIIA) is among the most potent bactericidal proteins against Gram-positive bacteria, including S. aureus. To determine hGIIA-resistance mechanisms of MRSA, we screened the Nebraska Transposon Mutant Library using a sublethal concentration of recombinant hGIIA. We identified and confirmed the role of lspA, encoding the lipoprotein signal peptidase LspA, as a new hGIIA resistance gene in both in vitro assays and an infection model in hGIIA-transgenic mice. Increased susceptibility of the lspA mutant was associated with enhanced activity of hGIIA on the cell membrane. Moreover, lspA deletion increased susceptibility to daptomycin, a last-resort antibiotic to treat MRSA infections. MRSA wild type could be sensitized to hGIIA and daptomycin killing through exposure to LspA-specific inhibitors globomycin and myxovirescin A1. Analysis of >26,000 S. aureus genomes showed that LspA is highly sequence-conserved, suggesting universal application of LspA inhibition. The role of LspA in hGIIA resistance was not restricted to MRSA since Streptococcus mutans and Enterococcus faecalis were also more hGIIA-susceptible after lspA deletion or LspA inhibition, respectively. Overall, our data suggest that pharmacological interference with LspA may disarm Gram-positive pathogens, including MRSA, to enhance clearance by innate host defense molecules and clinically applied antibiotics.
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Affiliation(s)
- Marieke M Kuijk
- Medical Microbiology and Infection Prevention, Amsterdam University Medical Centers, Location University of Amsterdam, Amsterdam, The Netherlands,
| | - Yongzheng Wu
- Unité de Biologie Cellulaire de l'Infection Microbionne, CNRS UMR3691, Institut Pasteur, Université de Paris Cité, Paris, France
| | - Vincent P van Hensbergen
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Gizem Shanlitourk
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Christine Payré
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne Sophia Antipolis, France
| | - Gérard Lambeau
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne Sophia Antipolis, France
| | - Sandra Man-Bovenkerk
- Medical Microbiology and Infection Prevention, Amsterdam University Medical Centers, Location University of Amsterdam, Amsterdam, The Netherlands
| | - Jennifer Herrmann
- Department of Pharmacy at Saarland University, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarbrücken, Germany
| | - Rolf Müller
- Department of Pharmacy at Saarland University, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarbrücken, Germany
| | - Jos A G van Strijp
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Yvonne Pannekoek
- Medical Microbiology and Infection Prevention, Amsterdam University Medical Centers, Location University of Amsterdam, Amsterdam, The Netherlands
| | - Lhousseine Touqui
- Mucoviscidose et Bronchopathies Chroniques, Institut Pasteur, Université de Paris Cité, Paris, France
- Sorbonne Université, INSERM UMR S 938, Centre de Recherche Saint-Antoine (CRSA), Paris, France
| | - Nina M van Sorge
- Medical Microbiology and Infection Prevention, Amsterdam University Medical Centers, Location University of Amsterdam, Amsterdam, The Netherlands
- Netherlands Reference Laboratory for Bacterial Meningitis, Amsterdam University Medical Centers, Amsterdam, The Netherlands
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23
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Afshar M, Møllebjerg A, Minero GA, Hollensteiner J, Poehlein A, Himmelbach A, Lange J, Meyer RL, Brüggemann H. Biofilm formation and inflammatory potential of Staphylococcus saccharolyticus: A possible cause of orthopedic implant-associated infections. Front Microbiol 2022; 13:1070201. [DOI: 10.3389/fmicb.2022.1070201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 11/09/2022] [Indexed: 11/29/2022] Open
Abstract
Staphylococcus saccharolyticus, a coagulase-negative staphylococcal species, has some unusual characteristics for human-associated staphylococci, such as slow growth and its preference for anoxic culture conditions. This species is a relatively abundant member of the human skin microbiota, but its microbiological properties, as well as the pathogenic potential, have scarcely been investigated so far, despite being occasionally isolated from different types of infections including orthopedic implant-associated infections. Here, we investigated the growth and biofilm properties of clinical isolates of S. saccharolyticus and determined host cell responses. Growth assessments in anoxic and oxic conditions revealed strain-dependent outcomes, as some strains can also grow aerobically. All tested strains of S. saccharolyticus were able to form biofilm in a microtiter plate assay. Strain-dependent differences were determined by optical coherence tomography, revealing that medium supplementation with glucose and sodium chloride enhanced biofilm formation. Visualization of the biofilm by confocal laser scanning microscopy revealed the role of extracellular DNA in the biofilm structure. In addition to attached biofilms, S. saccharolyticus also formed bacterial aggregates at an early stage of growth. Transcriptome analysis of biofilm-grown versus planktonic cells revealed a set of upregulated genes in biofilm-embedded cells, including factors involved in adhesion, colonization, and competition such as epidermin, type I toxin-antitoxin system, and phenol-soluble modulins (beta and epsilon). To investigate consequences for the host after encountering S. saccharolyticus, cytokine profiling and host cell viability were assessed by infection experiments with differentiated THP-1 cells. The microorganism strongly triggered the secretion of the tested pro-inflammatory cyto- and chemokines IL-6, IL-8, and TNF-alpha, determined at 24 h post-infection. S. saccharolyticus was less cytotoxic than Staphylococcus aureus. Taken together, the results indicate that S. saccharolyticus has substantial pathogenic potential. Thus, it can be a potential cause of orthopedic implant-associated infections and other types of deep-seated infections.
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24
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Mohammad M, Ali A, Nguyen MT, Götz F, Pullerits R, Jin T. Staphylococcus aureus lipoproteins in infectious diseases. Front Microbiol 2022; 13:1006765. [PMID: 36262324 PMCID: PMC9574248 DOI: 10.3389/fmicb.2022.1006765] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/06/2022] [Indexed: 11/13/2022] Open
Abstract
Infections with the Gram-positive bacterial pathogen Staphylococcus aureus remain a major challenge for the healthcare system and demand new treatment options. The increasing antibiotic resistance of S. aureus poses additional challenges, consequently inflicting a huge strain in the society due to enormous healthcare costs. S. aureus expresses multiple molecules, including bacterial lipoproteins (Lpps), which play a role not only in immune response but also in disease pathogenesis. S. aureus Lpps, the predominant ligands of TLR2, are important for bacterial survival as they maintain the metabolic activity of the bacteria. Moreover, Lpps possess many diverse properties that are of vital importance for the bacteria. They also contribute to host cell invasion but so far their role in different staphylococcal infections has not been fully defined. In this review, we summarize the current knowledge about S. aureus Lpps and their distinct roles in various infectious disease animal models, such as septic arthritis, sepsis, and skin and soft tissue infections. The molecular and cellular response of the host to S. aureus Lpp exposure is also a primary focus.
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Affiliation(s)
- Majd Mohammad
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- *Correspondence: Majd Mohammad,
| | - Abukar Ali
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Minh-Thu Nguyen
- Section of Medical and Geographical Infectiology, Institute of Medical Microbiology, University Hospital of Münster, Münster, Germany
| | - Friedrich Götz
- Department of Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Rille Pullerits
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Immunology and Transfusion Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Tao Jin
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Rheumatology, Sahlgrenska University Hospital, Gothenburg, Sweden
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25
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Zhou J, Cai Y, Liu Y, An H, Deng K, Ashraf MA, Zou L, Wang J. Breaking down the cell wall: Still an attractive antibacterial strategy. Front Microbiol 2022; 13:952633. [PMID: 36212892 PMCID: PMC9544107 DOI: 10.3389/fmicb.2022.952633] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/18/2022] [Indexed: 11/17/2022] Open
Abstract
Since the advent of penicillin, humans have known about and explored the phenomenon of bacterial inhibition via antibiotics. However, with changes in the global environment and the abuse of antibiotics, resistance mechanisms have been selected in bacteria, presenting huge threats and challenges to the global medical and health system. Thus, the study and development of new antimicrobials is of unprecedented urgency and difficulty. Bacteria surround themselves with a cell wall to maintain cell rigidity and protect against environmental insults. Humans have taken advantage of antibiotics to target the bacterial cell wall, yielding some of the most widely used antibiotics to date. The cell wall is essential for bacterial growth and virulence but is absent from humans, remaining a high-priority target for antibiotic screening throughout the antibiotic era. Here, we review the extensively studied targets, i.e., MurA, MurB, MurC, MurD, MurE, MurF, Alr, Ddl, MurI, MurG, lipid A, and BamA in the cell wall, starting from the very beginning to the latest developments to elucidate antimicrobial screening. Furthermore, recent advances, including MraY and MsbA in peptidoglycan and lipopolysaccharide, and tagO, LtaS, LspA, Lgt, Lnt, Tol-Pal, MntC, and OspA in teichoic acid and lipoprotein, have also been profoundly discussed. The review further highlights that the application of new methods such as macromolecular labeling, compound libraries construction, and structure-based drug design will inspire researchers to screen ideal antibiotics.
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Affiliation(s)
- Jingxuan Zhou
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Yi Cai
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Ying Liu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Haoyue An
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Kaihong Deng
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Muhammad Awais Ashraf
- Department of Microbiology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Lili Zou
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Jun Wang
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- *Correspondence: Jun Wang,
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Deletion of a previously uncharacterized lipoprotein lirL confers resistance to an inhibitor of type II signal peptidase in Acinetobacter baumannii. Proc Natl Acad Sci U S A 2022; 119:e2123117119. [PMID: 36099298 PMCID: PMC9499571 DOI: 10.1073/pnas.2123117119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Inhibiting bacterial lipoprotein biosynthesis in Enterobacteriaceae is an attractive antibacterial strategy to target multidrug resistance, and mechanisms of resistance to prolipoprotein signal peptidase (LspA) inhibitors in Escherichia coli are relatively well understood. In contrast, it has been challenging to understand the mechanisms of resistance to LspA inhibitors in Acinetobacter baumannii due to the substantially lower inhibitor potencies and the lack of a homologous lpp gene. By increasing the antibacterial potency of the LspA inhibitor, globomycin, against wild-type A. baumannii, we were able to examine resistance to LspA inhibitors, resulting in the identification of a previously uncharacterized highly abundant lipoprotein, LspA inhibitor resistance lipoprotein. This study reveals insights into resistance mechanisms of A. baumannii against inhibitors of bacterial lipoprotein biosynthesis. Acinetobacter baumannii is a clinically important, predominantly health care–associated gram-negative bacterium with high rates of emerging resistance worldwide. Given the urgent need for novel antibacterial therapies against A. baumannii, we focused on inhibiting lipoprotein biosynthesis, a pathway that is essential for envelope biogenesis in gram-negative bacteria. The natural product globomycin, which inhibits the essential type II signal peptidase prolipoprotein signal peptidase (LspA), is ineffective against wild-type A. baumannii clinical isolates due to its poor penetration through the outer membrane. Here, we describe a globomycin analog, G5132, that is more potent against wild-type and clinical A. baumannii isolates. Mutations leading to G5132 resistance in A. baumannii map to the signal peptide of a single hypothetical gene, which we confirm encodes an alanine-rich lipoprotein and have renamed lirL (prolipoprotein signal peptidase inhibitor resistance lipoprotein). LirL is a highly abundant lipoprotein primarily localized to the inner membrane. Deletion of lirL leads to G5132 resistance, inefficient cell division, increased sensitivity to serum, and attenuated virulence. Signal peptide mutations that confer resistance to G5132 lead to the accumulation of diacylglyceryl-modified LirL prolipoprotein in untreated cells without significant loss in cell viability, suggesting that these mutations overcome a block in lipoprotein biosynthetic flux by decreasing LirL prolipoprotein substrate sensitivity to processing by LspA. This study characterizes a lipoprotein that plays a critical role in resistance to LspA inhibitors and validates lipoprotein biosynthesis as a antibacterial target in A. baumannii.
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Utility of fatty acid profile and in vitro immune cell activation for chemical and biological standardization of Arthrospira/Limnospira. Sci Rep 2022; 12:15657. [PMID: 36123360 PMCID: PMC9485217 DOI: 10.1038/s41598-022-19590-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 08/31/2022] [Indexed: 11/27/2022] Open
Abstract
Commercially cultivated Limnospira (species formerly classified to genus Arthrospira) is a popular food/supplement consumed by millions of people worldwide for health benefits. The objective of the current research was to advance the standardization technology for Limnospira. Quantitative methods were established to detect fatty acids as potential chemical markers and immune-enhancing activity. Analysis of 20 different batches of biomass obtained from one commercial grower demonstrated that there was a statistically significant relationship between the sum of two fatty acids (linoleic and γ-linolenic) and Toll-like receptor (TLR)2/TLR1-dependent activation (R2 = 0.48, p = 0.0007). Investigation of 12 biomass samples sourced from growers in 10 different countries demonstrated that fatty acid content was again significantly correlated with biological activity (R2 = 0.72, p = 0.0005) and the content of fatty acids varied by twofold and activity by 12.5-fold. This large variation between different samples confirms the need to use the present standardization methods to ensure consistent and properly characterized biomass for consumers and for future scientific research.
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Antimicrobial Activity of Rhenium Di- and Tricarbonyl Diimine Complexes: Insights on Membrane-Bound S. aureus Protein Binding. Pharmaceuticals (Basel) 2022; 15:ph15091107. [PMID: 36145328 PMCID: PMC9501577 DOI: 10.3390/ph15091107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/31/2022] [Accepted: 08/31/2022] [Indexed: 11/16/2022] Open
Abstract
Antimicrobial resistance is one of the major human health threats, with significant impacts on the global economy. Antibiotics are becoming increasingly ineffective as drug-resistance spreads, imposing an urgent need for new and innovative antimicrobial agents. Metal complexes are an untapped source of antimicrobial potential. Rhenium complexes, amongst others, are particularly attractive due to their low in vivo toxicity and high antimicrobial activity, but little is known about their targets and mechanism of action. In this study, a series of rhenium di- and tricarbonyl diimine complexes were prepared and evaluated for their antimicrobial potential against eight different microorganisms comprising Gram-negative and -positive bacteria. Our data showed that none of the Re dicarbonyl or neutral tricarbonyl species have either bactericidal or bacteriostatic potential. In order to identify possible targets of the molecules, and thus possibly understand the observed differences in the antimicrobial efficacy of the molecules, we computationally evaluated the binding affinity of active and inactive complexes against structurally characterized membrane-bound S. aureus proteins. The computational analysis indicates two possible major targets for this class of compounds, namely lipoteichoic acids flippase (LtaA) and lipoprotein signal peptidase II (LspA). Our results, consistent with the published in vitro studies, will be useful for the future design of rhenium tricarbonyl diimine-based antibiotics.
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Sah D, Rai JPN, Ghosh A, Chakraborty M. A review on biosurfactant producing bacteria for remediation of petroleum contaminated soils. 3 Biotech 2022; 12:218. [PMID: 35965658 PMCID: PMC9365905 DOI: 10.1007/s13205-022-03277-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/21/2022] [Indexed: 11/01/2022] Open
Abstract
The discharge of potentially toxic petroleum hydrocarbons into the environment has been a matter of concern, as these organic pollutants accumulate in many ecosystems due to their hydrophobicity and low bioavailability. Petroleum hydrocarbons are neurotoxic and carcinogenic organic pollutants, extremely harmful to human and environmental health. Traditional treatment methods for removing hydrocarbons from polluted areas, including various mechanical and chemical strategies, are ineffective and costly. However, many indigenous microorganisms in soil and water can utilise hydrocarbon compounds as sources of carbon and energy and hence, can be employed to degrade hydrocarbon contaminants. Therefore, bioremediation using bacteria that degrade petroleum hydrocarbons is commonly viewed as an environmentally acceptable and effective method. The efficacy of bioremediation can be boosted further by using potential biosurfactant-producing microorganisms, as biosurfactants reduce surface tension, promote emulsification and micelle formation, making hydrocarbons bio-available for microbial breakdown. Further, introducing nanoparticles can improve the solubility of hydrophobic hydrocarbons as well as microbial synthesis of biosurfactants, hence establishing a favourable environment for microbial breakdown of these chemicals. The review provides insights into the role of microbes in the bioremediation of soils contaminated with petroleum hydrocarbons and emphasises the significance of biosurfactants and potential biosurfactant-producing bacteria. The review partly focusses on how nanotechnology is being employed in different critical bioremediation processes.
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Affiliation(s)
- Diksha Sah
- Department of Environmental Sciences, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand 263145 India
| | - J. P. N. Rai
- Department of Environmental Sciences, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand 263145 India
| | - Ankita Ghosh
- Department of Environmental Sciences, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand 263145 India
| | - Moumita Chakraborty
- Department of Environmental Sciences, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand 263145 India
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Zou J, Shang W, Yang L, Liu T, Wang L, Li X, Zhao J, Rao X, Gao J, Fan X. Microglia activation in the mPFC mediates anxiety-like behaviors caused by Staphylococcus aureus strain USA300. Brain Behav 2022; 12:e2715. [PMID: 35977050 PMCID: PMC9480961 DOI: 10.1002/brb3.2715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/19/2022] [Accepted: 07/07/2022] [Indexed: 11/15/2022] Open
Abstract
INTRODUCTION Staphylococcus aureus (S. aureus) is considered as one of the major causative agents of serious hospital- and community-acquired infections. Recent studies have reported that S. aureus infection induced neuroinflammation and was linked with some mental disorders. To evaluate the effects of S. aureus infection on abnormal behaviors, we conducted the present study. METHODS A S. aureus USA300-infected mouse model was established using bacterial suspension injection into tail vein. A series of behavioral tests were performed after USA300 infection. The expression of cytokines was detected in serum and mPFC. The number and some morphological parameters of microglia were also evaluated by immunofluorescence staining. RESULTS Anxiety-like behaviors, instead of locomotor activity impairment or depression-like behaviors, were observed in mice infected with S. aureus USA300 compared with control. S. aureus USA300 infection caused overexpression of IL-6, TNF-α, and IL-1β in serum, resulted in microglial over-activation and excessive release of proinflammatory cytokines in the mPFC. In addition, overexpression of TLR2 accompanied by increased GLS1 and p-STAT3 was observed in the mPFC of mice infected with S. aureus USA300. CONCLUSION This study provides evidence that S. aureus USA300 infection can lead to neuroinflammation in the mPFC of mice, which may contribute to the development of anxiety.
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Affiliation(s)
- Jiao Zou
- Department of Military Cognitive Psychology, School of Psychology, Third Military Medical University (Army Medical University), Chongqing, China
| | - Weilong Shang
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Ling Yang
- Department of Military Cognitive Psychology, School of Psychology, Third Military Medical University (Army Medical University), Chongqing, China
| | - Tianyao Liu
- Department of Military Cognitive Psychology, School of Psychology, Third Military Medical University (Army Medical University), Chongqing, China
| | - Lian Wang
- Department of Military Cognitive Psychology, School of Psychology, Third Military Medical University (Army Medical University), Chongqing, China
| | - Xin Li
- Department of Military Cognitive Psychology, School of Psychology, Third Military Medical University (Army Medical University), Chongqing, China
| | - Jinghui Zhao
- Department of Military Cognitive Psychology, School of Psychology, Third Military Medical University (Army Medical University), Chongqing, China
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Junwei Gao
- Department of Military Cognitive Psychology, School of Psychology, Third Military Medical University (Army Medical University), Chongqing, China
| | - Xiaotang Fan
- Department of Military Cognitive Psychology, School of Psychology, Third Military Medical University (Army Medical University), Chongqing, China
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He LY, Yu YB, Liu Y, Le YJ, Li S, Yang XY. Immunization with the lipoprotein FtsB stimulates protective immunity against Streptococcus pyogenes infection in mice. Front Microbiol 2022; 13:969490. [PMID: 36016779 PMCID: PMC9396372 DOI: 10.3389/fmicb.2022.969490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/22/2022] [Indexed: 11/13/2022] Open
Abstract
Streptococcus pyogenes is one of the main pathogenic bacteria that causes disease in humans. It is reported that over 18 million cases of S. pyogenes disease occurred in the world, and more than 500,000 deaths occur annually worldwide. An effective vaccine is widely regarded as the most reliable way to control and prevent streptococcal infections. However, there is currently no approved vaccine for S. pyogenes. In this study, we evaluated the potential of lipoprotein FtsB as a new vaccine candidate to prevent S. pyogenes infection. Mice vaccinated with purified FtsB protein elicited high titers of IgG, IgG1 and IgG2a antibodies in mouse serum. Vaccinated with FtsB can reduce bacterial systemic dissemination in the blood, heart, and spleen and reduce organ damage in the mouse bacteremia model. In addition, active immunization with FtsB protected against streptococcal abscess formation. Furthermore, immunization with FtsB was efficient in inducing a mixed cellular immune response and promoting the maturation of dendritic cells in mice. The lipoprotein HtsA was served as a positive control because it has been reported to protect mice from S. pyogenes infection in both active and passive immunization. These findings demonstrated that lipoprotein FtsB may serve as a candidate vaccine for the prevention of S. pyogenes infection.
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Cao L, Li N, Dong Y, Yang XY, Liu J, He QY, Ge R, Sun X. SPD_0090 Negatively Contributes to Virulence of Streptococcus pneumoniae. Front Microbiol 2022; 13:896896. [PMID: 35770170 PMCID: PMC9234739 DOI: 10.3389/fmicb.2022.896896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/13/2022] [Indexed: 11/30/2022] Open
Abstract
In most bacteria, iron plays an important role in the survival of bacteria and the process of infection to the host. Streptococcus pneumoniae (S. pneumoniae) evolved three iron transporters (i.e., PiaABC, PiuABC, and PitABC) responsible for the transportation of three kinds of iron (i.e., ferrichrome, hemin, and ferric ion). Our previous study showed that both mRNA and protein levels of SPD_0090 were significantly upregulated in the ΔpiuA/ΔpiaA/ΔpitA triple mutant, but its detailed biological function is unknown. In this study, we constructed spd_0090 knockout and complement strain and found that the deletion of spd_0090 hinders bacterial growth. SPD_0090 is located on the cell membrane and affects the hemin utilization ability of S. pneumoniae. The cell infection model showed that the knockout strain had stronger invasion and adhesion ability. Notably, knockout of the spd_0090 gene resulted in an enhanced infection ability of S. pneumoniae in mice by increasing the expression of virulence factors. Furthermore, iTRAQ quantitative proteomics studies showed that the knockout of spd_0090 inhibited carbon metabolism and thus suppressed bacterial growth. Our study showed that SPD_0090 negatively regulates the virulence of S. pneumoniae.
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Affiliation(s)
- Linlin Cao
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Nan Li
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Yingshan Dong
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Xiao-Yan Yang
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Jiajia Liu
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Qing-Yu He
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
- *Correspondence: Qing-Yu He,
| | - Ruiguang Ge
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Ruiguang Ge,
| | - Xuesong Sun
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
- Xuesong Sun,
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Horn KJ, Schopper MA, Drigot ZG, Clark SE. Airway Prevotella promote TLR2-dependent neutrophil activation and rapid clearance of Streptococcus pneumoniae from the lung. Nat Commun 2022; 13:3321. [PMID: 35680890 PMCID: PMC9184549 DOI: 10.1038/s41467-022-31074-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 05/31/2022] [Indexed: 12/13/2022] Open
Abstract
This study investigates how specific members of the lung microbiome influence the early immune response to infection. Prevotella species are a major component of the endogenous airway microbiota. Increased abundance of Prevotella melaninogenica correlates with reduced infection with the bacterial pathogen Streptococcus pneumoniae, indicating a potentially beneficial role. Here, we show that P. melaninogenica enhances protection against S. pneumoniae, resulting in rapid pathogen clearance from the lung and improved survival in a mouse lung co-infection model. This response requires recognition of P. melaninogenica lipoproteins by toll-like receptor (TLR)2, the induction of TNFα, and neutrophils, as the loss of any of these factors abrogates Prevotella-induced protection. Improved clearance of S. pneumoniae is associated with increased serine protease-mediated killing by lung neutrophils and restraint of P. melaninogenica-induced inflammation by IL-10 in co-infected mice. Together, these findings highlight innate immune priming by airway Prevotella as an important protective feature in the respiratory tract. How the airway microbiome protects against bacterial pneumonia remains unclear. Here, the authors identify airway bacterial species that activate the immune system to facilitate rapid clearance of the pathogen Streptococcus pneumoniae from the lung.
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Affiliation(s)
- Kadi J Horn
- University of Colorado School of Medicine, Department of Otolaryngology, Aurora, CO, 80045, USA
| | - Melissa A Schopper
- University of Colorado School of Medicine, Department of Otolaryngology, Aurora, CO, 80045, USA
| | - Zoe G Drigot
- University of Colorado School of Medicine, Department of Otolaryngology, Aurora, CO, 80045, USA.,University of Colorado Boulder, College of Arts and Sciences, Boulder, CO, 80309, USA
| | - Sarah E Clark
- University of Colorado School of Medicine, Department of Otolaryngology, Aurora, CO, 80045, USA.
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Norpi ASM, Nordin ML, Ahmad N, Katas H, Fuaad AAHA, Sukri A, Marasini N, Azmi F. New modular platform based on multi-adjuvanted amphiphilic chitosan nanoparticles for efficient lipopeptide vaccine delivery against group A streptococcus. Asian J Pharm Sci 2022; 17:435-446. [PMID: 35782331 PMCID: PMC9237632 DOI: 10.1016/j.ajps.2022.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 04/01/2022] [Accepted: 04/06/2022] [Indexed: 11/02/2022] Open
Abstract
An effective vaccine against group A streptococcus (GAS) is highly desirable for definitive control of GAS infections. In the present study, two variants of amphiphilic chitosan nanoparticles-based GAS vaccines were developed. The vaccines were primarily composed of encapsulated KLH protein (a source of T helper cell epitopes) and lipidated M-protein derived B cell peptide epitope (lipoJ14) within the amphiphilic structure of nanoparticles. The only difference between them was one of the nanoparticles vaccines received additional surface coating with poly (I:C). The formulated vaccines exhibited nanosized particles within the range of 220–240 nm. Cellular uptake study showed that nanoparticles vaccine without additional poly (I:C) coating has greater uptake by dendritic cells and macrophages compared to nanoparticles vaccine that was functionalized with poly (I:C). Both vaccines were found to be safe in mice and showed negligible cytotoxicity against HEK293 cells. Upon immunization in mice, both nanoparticle vaccines produced high antigen-specific antibodies titres that were regulated by a balanced Th1 and Th2 response compared to physical mixture. These antibodies elicited high opsonic activity against the tested GAS strains. Overall, our data demonstrated that amphiphilic chitosan nanoparticles platform induced a potent immune response even without additional inclusion of poly (I:C).
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Schultz M, Mohammad M, Nguyen MT, Hu Z, Jarneborn A, Wienken CM, Froning M, Pullerits R, Ali A, Hayen H, Götz F, Jin T. Lipoproteins Cause Bone Resorption in a Mouse Model of Staphylococcus aureus Septic Arthritis. Front Microbiol 2022; 13:843799. [PMID: 35356518 PMCID: PMC8959583 DOI: 10.3389/fmicb.2022.843799] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 01/26/2022] [Indexed: 12/21/2022] Open
Abstract
Septic arthritis, most often caused by Staphylococcus aureus, is a rapidly progressive and destructive joint disease with substantial mortality and morbidity. Staphylococcus aureus lipoproteins (Lpps) are known to induce arthritis and bone destruction. Here, we aimed to investigate the bone resorptive effect of S. aureus Lpps in a murine arthritis model by intra-articular injection of purified S. aureus Lpps, synthetic lipopeptides, and live S. aureus strains. Analyses of the bone mineral density (BMD) of the distal femur bone were performed. Intra-articular injection of both live S. aureus and purified S. aureus Lpps were shown to significantly decrease total- and trabecular BMD. Liquid chromatography–mass spectrometry analyses revealed that the Lpps expressed by S. aureus SA113 strain contain both diacyl and triacyl lipid moieties. Interestingly, synthetic diacylated lipopeptide, Pam2CSK4, was more potent in inducing bone resorption than synthetic triacylated lipopeptide, Pam3CSK4. Modified lipoproteins lacking the lipid moiety were deprived of their bone resorptive abilities. Monocyte depletion by clodronate liposomes fully abrogated the bone resorptive capacity of S. aureus lipoproteins. Our data suggest that S. aureus Lpps induce bone resorption in locally-induced murine arthritis, an effect mediated by their lipid-moiety through monocytes/macrophages.
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Affiliation(s)
- Michelle Schultz
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Majd Mohammad
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- *Correspondence: Majd Mohammad,
| | - Minh-Thu Nguyen
- Institute of Medical Microbiology, University Hospital of Münster, Münster, Germany
| | - Zhicheng Hu
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Microbiology and Immunology, The Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Anders Jarneborn
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Rheumatology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Carina M. Wienken
- Institute of Inorganic and Analytical Chemistry, University of Münster, Münster, Germany
| | - Matti Froning
- Institute of Inorganic and Analytical Chemistry, University of Münster, Münster, Germany
| | - Rille Pullerits
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Immunology and Transfusion Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Abukar Ali
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Heiko Hayen
- Institute of Inorganic and Analytical Chemistry, University of Münster, Münster, Germany
| | - Friedrich Götz
- Department of Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Tao Jin
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Rheumatology, Sahlgrenska University Hospital, Gothenburg, Sweden
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36
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Quiescence of Human Monocytes after Affinity Purification: A Novel Method Apt for Monocyte Stimulation Assays. Biomolecules 2022; 12:biom12030395. [PMID: 35327587 PMCID: PMC8945441 DOI: 10.3390/biom12030395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/23/2022] [Accepted: 03/01/2022] [Indexed: 01/25/2023] Open
Abstract
Several methods to isolate monocytes from whole blood have been previously published, with different advantages and disadvantages. For the purpose of cytokine release assessment upon external stimulation, the use of monocyte preparations consisting of non-activated cells is prerequisite. Affinity-isolated monocyte preparations from peripheral blood mononuclear cells (PBMCs), obtained via positive or negative selection using magnetic beads, released pro-inflammatory cytokines such as TNF-α and IL-6 even without adding external stimuli, hindering any assessment of an effect of bacterial lipoproteins on cell stimulation. Hence, the cell preparation protocol was modified by adding a quiescence step on repellent surface culture plates, dampening any monocyte pre-activation. This protocol now provides a robust method to prepare silent yet fully activatable, pure monocyte populations for further use in stimulus-elicited activation experiments.
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37
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Kroniger T, Flender D, Schlüter R, Köllner B, Trautwein-Schult A, Becher D. Proteome analysis of the Gram-positive fish pathogen Renibacterium salmoninarum reveals putative role of membrane vesicles in virulence. Sci Rep 2022; 12:3003. [PMID: 35194033 PMCID: PMC8863785 DOI: 10.1038/s41598-022-06130-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 01/04/2022] [Indexed: 12/11/2022] Open
Abstract
Bacterial kidney disease (BKD) is a chronic bacterial disease affecting both wild and farmed salmonids. The causative agent for BKD is the Gram-positive fish pathogen Renibacterium salmoninarum. As treatment and prevention of BKD have proven to be difficult, it is important to know and identify the key bacterial proteins that interact with the host. We used subcellular fractionation to report semi-quantitative data for the cytosolic, membrane, extracellular, and membrane vesicle (MV) proteome of R. salmoninarum. These data can aid as a backbone for more targeted experiments regarding the development of new drugs for the treatment of BKD. Further analysis was focused on the MV proteome, where both major immunosuppressive proteins P57/Msa and P22 and proteins involved in bacterial adhesion were found in high abundance. Interestingly, the P22 protein was relatively enriched only in the extracellular and MV fraction, implicating that MVs may play a role in host–pathogen interaction. Compared to the other subcellular fractions, the MVs were also relatively enriched in lipoproteins and all four cell wall hydrolases belonging to the New Lipoprotein C/Protein of 60 kDa (NlpC/P60) family were detected, suggesting an involvement in the formation of the MVs.
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Affiliation(s)
- Tobias Kroniger
- Institute of Microbiology, Department of Microbial Proteomics, Center for Functional Genomics of Microbes, University of Greifswald, 17489, Greifswald, Germany
| | - Daniel Flender
- Institute of Microbiology, Department of Microbial Proteomics, Center for Functional Genomics of Microbes, University of Greifswald, 17489, Greifswald, Germany
| | - Rabea Schlüter
- Imaging Center of the Department of Biology, University of Greifswald, 17489, Greifswald, Germany
| | - Bernd Köllner
- Institute of Immunology, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, 17493, Greifswald - Isle of Riems, Germany
| | - Anke Trautwein-Schult
- Institute of Microbiology, Department of Microbial Proteomics, Center for Functional Genomics of Microbes, University of Greifswald, 17489, Greifswald, Germany
| | - Dörte Becher
- Institute of Microbiology, Department of Microbial Proteomics, Center for Functional Genomics of Microbes, University of Greifswald, 17489, Greifswald, Germany.
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38
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Krueger A, Zaugg J, Chisholm S, Linedale R, Lachner N, Teoh SM, Tuong ZK, Lukowski SW, Morrison M, Soyer HP, Hugenholtz P, Hill MM, Frazer IH. Secreted Toxins From Staphylococcus aureus Strains Isolated From Keratinocyte Skin Cancers Mediate Pro-tumorigenic Inflammatory Responses in the Skin. Front Microbiol 2022; 12:789042. [PMID: 35145494 PMCID: PMC8822148 DOI: 10.3389/fmicb.2021.789042] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/08/2021] [Indexed: 12/27/2022] Open
Abstract
Squamous cell carcinoma (SCC) is a common type of skin cancer that typically arises from premalignant precursor lesions named actinic keratoses (AK). Chronic inflammation is a well-known promoter of skin cancer progression. AK and SCC have been associated with an overabundance of the bacterium Staphylococcus aureus (S. aureus). Certain secreted products from S. aureus are known to promote cutaneous pro-inflammatory responses; however, not all S. aureus strains produce these. As inflammation plays a key role in SCC development, we investigated the pro-inflammatory potential and toxin secretion profiles of skin-cancer associated S. aureus. Sterile culture supernatants (“secretomes”) of S. aureus clinical strains isolated from AK and SCC were applied to human keratinocytes in vitro. Some S. aureus secretomes induced keratinocytes to overexpress inflammatory mediators that have been linked to skin carcinogenesis, including IL-6, IL-8, and TNFα. A large phenotypic variation between the tested clinical strains was observed. Strains that are highly pro-inflammatory in vitro also caused more pronounced skin inflammation in mice. Proteomic characterization of S. aureus secretomes using mass spectrometry established that specific S. aureus enzymes and cytolytic toxins, including hemolysins, phenol-soluble modulins, and serine proteases, as well as currently uncharacterized proteins, correlate with the pro-inflammatory S. aureus phenotype. This study is the first to describe the toxin secretion profiles of AK and SCC-associated S. aureus, and their potential to induce a pro-inflammatory environment in the skin. Further studies are needed to establish whether these S. aureus products promote SCC development by mediating chronic inflammation.
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Affiliation(s)
- Annika Krueger
- Faculty of Medicine, The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - Julian Zaugg
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Sarah Chisholm
- Faculty of Medicine, The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - Richard Linedale
- Faculty of Medicine, The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - Nancy Lachner
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Siok Min Teoh
- Faculty of Medicine, The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - Zewen K. Tuong
- Faculty of Medicine, The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Woolloongabba, QLD, Australia
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
- Cellular Genetics, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Samuel W. Lukowski
- The Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Mark Morrison
- Faculty of Medicine, The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - H. Peter Soyer
- Dermatology Research Centre, The University of Queensland Diamantina Institute, The University of Queensland, Brisbane, QLD, Australia
- Dermatology Department, Princess Alexandra Hospital, Brisbane, QLD, Australia
| | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Michelle M. Hill
- Faculty of Medicine, The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Woolloongabba, QLD, Australia
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
- The University of Queensland Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Ian H. Frazer
- Faculty of Medicine, The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Woolloongabba, QLD, Australia
- *Correspondence: Ian H. Frazer,
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Jha N, Hall D, Kanakan A, Mehta P, Maurya R, Mir Q, Gill HM, Janga SC, Pandey R. Geographical Landscape and Transmission Dynamics of SARS-CoV-2 Variants Across India: A Longitudinal Perspective. Front Genet 2022; 12:753648. [PMID: 34976008 PMCID: PMC8719586 DOI: 10.3389/fgene.2021.753648] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 11/17/2021] [Indexed: 12/21/2022] Open
Abstract
Globally, SARS-CoV-2 has moved from one tide to another with ebbs in between. Genomic surveillance has greatly aided the detection and tracking of the virus and the identification of the variants of concern (VOC). The knowledge and understanding from genomic surveillance is important for a populous country like India for public health and healthcare officials for advance planning. An integrative analysis of the publicly available datasets in GISAID from India reveals the differential distribution of clades, lineages, gender, and age over a year (Apr 2020–Mar 2021). The significant insights include the early evidence towards B.1.617 and B.1.1.7 lineages in the specific states of India. Pan-India longitudinal data highlighted that B.1.36* was the predominant clade in India until January–February 2021 after which it has gradually been replaced by the B.1.617.1 lineage, from December 2020 onward. Regional analysis of the spread of SARS-CoV-2 indicated that B.1.617.3 was first seen in India in the month of October in the state of Maharashtra, while the now most prevalent strain B.1.617.2 was first seen in Bihar and subsequently spread to the states of Maharashtra, Gujarat, and West Bengal. To enable a real time understanding of the transmission and evolution of the SARS-CoV-2 genomes, we built a transmission map available on https://covid19-indiana.soic.iupui.edu/India/EmergingLineages/April2020/to/March2021. Based on our analysis, the rate estimate for divergence in our dataset was 9.48 e-4 substitutions per site/year for SARS-CoV-2. This would enable pandemic preparedness with the addition of future sequencing data from India available in the public repositories for tracking and monitoring the VOCs and variants of interest (VOI). This would help aid decision making from the public health perspective.
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Affiliation(s)
- Neha Jha
- Integrative Genomics of Host-Pathogen (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
| | - Dwight Hall
- Department of Biohealth Informatics, School of Informatics and Computing, Indiana University Purdue University, Indianapolis, IN, United States
| | - Akshay Kanakan
- Integrative Genomics of Host-Pathogen (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
| | - Priyanka Mehta
- Integrative Genomics of Host-Pathogen (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
| | - Ranjeet Maurya
- Integrative Genomics of Host-Pathogen (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Quoseena Mir
- Department of Biohealth Informatics, School of Informatics and Computing, Indiana University Purdue University, Indianapolis, IN, United States
| | - Hunter Mathias Gill
- Department of Biohealth Informatics, School of Informatics and Computing, Indiana University Purdue University, Indianapolis, IN, United States
| | - Sarath Chandra Janga
- Department of Biohealth Informatics, School of Informatics and Computing, Indiana University Purdue University, Indianapolis, IN, United States
| | - Rajesh Pandey
- Integrative Genomics of Host-Pathogen (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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40
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Liu B, Li Q, Gong Z, Zhao J, Gu B, Feng S. Staphylococcus aureus lipoproteins play crucial roles in inducing inflammatory responses and bacterial internalization into bovine mammary epithelial cells. Microb Pathog 2021; 162:105364. [PMID: 34921958 DOI: 10.1016/j.micpath.2021.105364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 11/11/2021] [Accepted: 12/14/2021] [Indexed: 01/10/2023]
Abstract
Bovine mastitis is caused by bacterial infection and characterized by inflammatory and infectious processes. Staphylococcus aureus frequently causes subclinical mastitis in dairy cows. In this study, we aimed to investigate the roles of S. aureus lipoproteins in inducing inflammatory responses and in mediating bacterial internalization into bovine mammary epithelial cells (bMECs). The results showed that TLR2 expression in bMECs infected with S. aureus isogenic mutant deficient in lipoprotein maturation was decreased compared to that in bMECs infected with wild-type S. aureus. Lipoproteins from S. aureus and the engagement of TLR2 were essential for inducing the activation of MAPK and NF-κB signaling, and stimulating the secretion of the inflammatory mediators tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and C-X-C motif chemokine ligand 8 (CXCL8). The production of prostaglandin E2 (PGE2) and the expression of PTGS2 in S. aureus-infected bMECs were dependent on the presence of bacterial lipoproteins. Furthermore, bacterial lipoproteins contributed to S. aureus internalization into bMECs. These findings suggest the S. aureus lipoproteins are key immunobiologically active compounds that trigger inflammatory responses in bMECs and play an important role in S. aureus internalization into bMECs.
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Affiliation(s)
- Bo Liu
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 306, Zhaowuda Road, Saihan District, 010018, Hohhot, China
| | - Qianru Li
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 306, Zhaowuda Road, Saihan District, 010018, Hohhot, China
| | - Zhiguo Gong
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 306, Zhaowuda Road, Saihan District, 010018, Hohhot, China
| | - Jiamin Zhao
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 306, Zhaowuda Road, Saihan District, 010018, Hohhot, China
| | - Baichen Gu
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 306, Zhaowuda Road, Saihan District, 010018, Hohhot, China
| | - Shuang Feng
- Laboratory of Veterinary Public Health, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 306, Zhaowuda Road, Saihan District, 010018, Hohhot, China.
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41
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Smithers L, Olatunji S, Caffrey M. Bacterial Lipoprotein Posttranslational Modifications. New Insights and Opportunities for Antibiotic and Vaccine Development. Front Microbiol 2021; 12:788445. [PMID: 34950121 PMCID: PMC8689077 DOI: 10.3389/fmicb.2021.788445] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 11/16/2021] [Indexed: 12/17/2022] Open
Abstract
Lipoproteins are some of the most abundant proteins in bacteria. With a lipid anchor to the cell membrane, they function as enzymes, inhibitors, transporters, structural proteins, and as virulence factors. Lipoproteins activate the innate immune system and have biotechnological applications. The first lipoprotein was described by Braun and Rehn in 1969. Up until recently, however, work on lipoproteins has been sluggish, in part due to the challenges of handling proteins that are anchored to membranes by covalently linked lipids or are membrane integral. Activity in the area has quickened of late. In the past 5 years, high-resolution structures of the membrane enzymes of the canonical lipoprotein synthesis pathway have been determined, new lipoprotein types have been discovered and the enzymes responsible for their synthesis have been characterized biochemically. This has led to a flurry of activity aimed at developing novel antibiotics targeting these enzymes. In addition, surface exposed bacterial lipoproteins have been utilized as candidate vaccine antigens, and their potential to act as self-adjuvanting antigens is increasingly recognized. A summary of the latest developments in lipoproteins and their synthesis, as well as how this information is being exploited for therapeutic purposes is presented here.
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Affiliation(s)
- Luke Smithers
- School of Medicine, Trinity College Dublin, Dublin, Ireland
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
| | - Samir Olatunji
- School of Medicine, Trinity College Dublin, Dublin, Ireland
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
| | - Martin Caffrey
- School of Medicine, Trinity College Dublin, Dublin, Ireland
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
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42
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Cheung GYC, Bae JS, Otto M. Pathogenicity and virulence of Staphylococcus aureus. Virulence 2021; 12:547-569. [PMID: 33522395 PMCID: PMC7872022 DOI: 10.1080/21505594.2021.1878688] [Citation(s) in RCA: 404] [Impact Index Per Article: 134.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 12/15/2022] Open
Abstract
Staphylococcus aureus is one of the most frequent worldwide causes of morbidity and mortality due to an infectious agent. This pathogen can cause a wide variety of diseases, ranging from moderately severe skin infections to fatal pneumonia and sepsis. Treatment of S. aureus infections is complicated by antibiotic resistance and a working vaccine is not available. There has been ongoing and increasing interest in the extraordinarily high number of toxins and other virulence determinants that S. aureus produces and how they impact disease. In this review, we will give an overview of how S. aureus initiates and maintains infection and discuss the main determinants involved. A more in-depth understanding of the function and contribution of S. aureus virulence determinants to S. aureus infection will enable us to develop anti-virulence strategies to counteract the lack of an anti-S. aureus vaccine and the ever-increasing shortage of working antibiotics against this important pathogen.
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Affiliation(s)
- Gordon Y. C. Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
| | - Justin S. Bae
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
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43
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Can-Herrera LA, Gutierrez-Canul CD, Dzul-Cervantes MAA, Pacheco-Salazar OF, Chi-Cortez JD, Carbonell LS. Identification by molecular techniques of halophilic bacteria producing important enzymes from pristine area in Campeche, Mexico. BRAZ J BIOL 2021; 83:e246038. [PMID: 34495150 DOI: 10.1590/1519-6984.246038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 04/02/2021] [Indexed: 11/22/2022] Open
Abstract
Isla Arena is located in the coordinate 20° 70´ N - 90° 45´ W, from Campeche, Mexico. In these estuaries, the ocean mixes with fresh water, and ecosystems are concentrated where petenes and pink flamingos proliferate. Crustaceans and mollusks abound in the sea. Despite its enormous marine wealth, there are no studies carried out on which halophilic microorganisms are present in these waters. In this work, the diversity and structure of the microbial community was investigated through a metagenomics approach and corroborated for sequencing of 16S rRNA genes. It was found that the phylum Fimicutes predominates with more than 50%, in almost the same proportion of the class Bacilli and with almost 41% of relative abundance of the order Bacillales. The sequencing results showed that one of the samples presented a high percentage of similarity (99.75%) using the Nucleotide BLAST program with a peculiar microorganism: Bacillus subtilis. This microorganism is one of the best characterized bacteria among the gram-positive ones. Our results demonstrate that B. subtilis can be an efficient source of proteases, lipases and cellulases, from halophilic microbial communities located in poorly explored areas.
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Affiliation(s)
- L A Can-Herrera
- Instituto Tecnológico Superior de Calkiní en el Estado de Campeche - ITESCAM, Calkiní, Campeche, México
| | - C D Gutierrez-Canul
- Instituto Tecnológico Superior de Calkiní en el Estado de Campeche - ITESCAM, Calkiní, Campeche, México
| | - M A A Dzul-Cervantes
- Instituto Tecnológico Superior de Calkiní en el Estado de Campeche - ITESCAM, Calkiní, Campeche, México
| | - O F Pacheco-Salazar
- Instituto Tecnológico Superior de Calkiní en el Estado de Campeche - ITESCAM, Calkiní, Campeche, México
| | - J D Chi-Cortez
- Centro de Investigación Científica de Yucatán - CICY, Unidad de Ciencias Biológicas, Mérida, Yucatán, México
| | - L Saenz Carbonell
- Centro de Investigación Científica de Yucatán - CICY, Unidad de Ciencias Biológicas, Mérida, Yucatán, México
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44
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Hook JS, Patel PA, O'Malley A, Xie L, Kavanaugh JS, Horswill AR, Moreland JG. Lipoproteins from Staphylococcus aureus Drive Neutrophil Extracellular Trap Formation in a TLR2/1- and PAD-Dependent Manner. THE JOURNAL OF IMMUNOLOGY 2021; 207:966-973. [PMID: 34290104 DOI: 10.4049/jimmunol.2100283] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/25/2021] [Indexed: 11/19/2022]
Abstract
Neutrophils, polymorphonuclear leukocytes (PMN), play a critical role in the innate immune response to Staphylococcus aureus, a pathogen that continues to be associated with significant morbidity and mortality. Neutrophil extracellular trap (NET) formation is involved in ensnaring and killing of S. aureus, but this host-pathogen interaction also leads to host tissue damage. Importantly, NET components including neutrophil proteases are under consideration as therapeutic targets in a variety of disease processes. Although S. aureus lipoproteins are recognized to activate cells via TLRs, specific mechanisms of interaction with neutrophils are poorly delineated. We hypothesized that a lipoprotein-containing cell membrane preparation from methicillin-resistant S. aureus (MRSA-CMP) would elicit PMN activation, including NET formation. We investigated MRSA-CMP-elicited NET formation, regulated elastase release, and IL-8 production in human neutrophils. We studied PMN from healthy donors with or without a common single-nucleotide polymorphism in TLR1, previously demonstrated to impact TLR2/1 signaling, and used cell membrane preparation from both wild-type methicillin-resistant S. aureus and a mutant lacking palmitoylated lipoproteins (lgt). MRSA-CMP elicited NET formation, elastase release, and IL-8 production in a lipoprotein-dependent manner. TLR2/1 signaling was involved in NET formation and IL-8 production, but not elastase release, suggesting that MRSA-CMP-elicited elastase release is not mediated by triacylated lipoproteins. MRSA-CMP also primed neutrophils for enhanced NET formation in response to a subsequent stimulus. MRSA-CMP-elicited NET formation did not require Nox2-derived reactive oxygen species and was partially dependent on the activity of peptidyl arginine deiminase (PAD). In conclusion, lipoproteins from S. aureus mediate NET formation via TLR2/1 with clear implications for patients with sepsis.
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Affiliation(s)
- Jessica S Hook
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Parth A Patel
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Aidan O'Malley
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Lihua Xie
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Jeffrey S Kavanaugh
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO.,Department of Veterans Affairs, Eastern Colorado Healthcare System, Aurora, CO; and
| | - Jessica G Moreland
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX; .,Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX
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45
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Olatunji S, Bowen K, Huang CY, Weichert D, Singh W, Tikhonova IG, Scanlan EM, Olieric V, Caffrey M. Structural basis of the membrane intramolecular transacylase reaction responsible for lyso-form lipoprotein synthesis. Nat Commun 2021; 12:4254. [PMID: 34253723 PMCID: PMC8275575 DOI: 10.1038/s41467-021-24475-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/08/2021] [Indexed: 11/08/2022] Open
Abstract
Lipoproteins serve diverse functions in the bacterial cell and some are essential for survival. Some lipoproteins are adjuvants eliciting responses from the innate immune system of the host. The growing list of membrane enzymes responsible for lipoprotein synthesis includes the recently discovered lipoprotein intramolecular transacylase, Lit. Lit creates a lipoprotein that is less immunogenic, possibly enabling the bacteria to gain a foothold in the host by stealth. Here, we report the crystal structure of the Lit enzyme from Bacillus cereus and describe its mechanism of action. Lit consists of four transmembrane helices with an extracellular cap. Conserved residues map to the cap-membrane interface. They include two catalytic histidines that function to effect unimolecular transacylation. The reaction involves acyl transfer from the sn-2 position of the glyceryl moiety to the amino group on the N-terminal cysteine of the substrate via an 8-membered ring intermediate. Transacylation takes place in a confined aromatic residue-rich environment that likely evolved to bring distant moieties on the substrate into proximity and proper orientation for catalysis.
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Affiliation(s)
- Samir Olatunji
- Membrane Structural and Functional Biology Group, School of Medicine and School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
| | - Katherine Bowen
- School of Chemistry, Trinity College Dublin, Dublin, Ireland
| | - Chia-Ying Huang
- Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland
| | - Dietmar Weichert
- Membrane Structural and Functional Biology Group, School of Medicine and School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
| | - Warispreet Singh
- School of Pharmacy, Queen's University Belfast, Belfast, United Kingdom
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
- Hub for Biotechnology in Build Environment, Newcastle upon Tyne, United Kingdom
| | - Irina G Tikhonova
- School of Pharmacy, Queen's University Belfast, Belfast, United Kingdom
| | - Eoin M Scanlan
- School of Chemistry, Trinity College Dublin, Dublin, Ireland
| | - Vincent Olieric
- Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland
| | - Martin Caffrey
- Membrane Structural and Functional Biology Group, School of Medicine and School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland.
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Abstract
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The development of
lipopeptides (lipidated peptides) for vaccines
is discussed, including their role as antigens and/or adjuvants. Distinct
classes of lipopeptide architectures are covered including simple
linear and ligated constructs and lipid core peptides. The design,
synthesis, and immunological responses of the important class of glycerol-based
Toll-like receptor agonist lipopeptides such as Pam3CSK4, which contains three palmitoyl chains and a CSK4 hexapeptide sequence, and many derivatives of this model immunogenic
compound are also reviewed. Self-assembled lipopeptide structures
including spherical and worm-like micelles that have been shown to
act as vaccine agents are also described. The work discussed includes
examples of lipopeptides developed with model antigens, as well as
for immunotherapies to treat many infectious diseases including malaria,
influenza, hepatitis, COVID-19, and many others, as well as cancer
immunotherapies. Some of these have proceeded to clinical development.
The research discussed highlights the huge potential of, and diversity
of roles for, lipopeptides in contemporary and future vaccine development.
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Affiliation(s)
- Ian W Hamley
- Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, U.K
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47
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Lipoproteins Are Responsible for the Pro-Inflammatory Property of Staphylococcus aureus Extracellular Vesicles. Int J Mol Sci 2021; 22:ijms22137099. [PMID: 34281154 PMCID: PMC8268867 DOI: 10.3390/ijms22137099] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 01/08/2023] Open
Abstract
Staphylococcal aureus
(S. aureus), a Gram-positive bacteria, is known to cause various infections. Extracellular vesicles (EVs) are a heterogeneous array of membranous structures secreted by cells from all three domains of life, i.e., eukaryotes, bacteria, and archaea. Bacterial EVs are implied to be involved in both bacteria–bacteria and bacteria–host interactions during infections. It is still unclear how S. aureus EVs interact with host cells and induce inflammatory responses. In this study, EVs were isolated from S. aureus and mutant strains deficient in either prelipoprotein lipidation (Δlgt) or major surface proteins (ΔsrtAB). Their immunostimulatory capacities were assessed both in vitro and in vivo. We found that S. aureus EVs induced pro-inflammatory responses both in vitro and in vivo. However, this activity was dependent on lipidated lipoproteins (Lpp), since EVs isolated from the Δlgt showed no stimulation. On the other hand, EVs isolated from the ΔsrtAB mutant showed full immune stimulation, indicating the cell wall anchoring of surface proteins did not play a role in immune stimulation. The immune stimulation of S. aureus EVs was mediated mainly by monocytes/macrophages and was TLR2 dependent. In this study, we demonstrated that not only free Lpp but also EV-imbedded Lpp had high pro-inflammatory activity.
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48
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Research progress on Toll-like receptor signal transduction and its roles in antimicrobial immune responses. Appl Microbiol Biotechnol 2021; 105:5341-5355. [PMID: 34180006 PMCID: PMC8236385 DOI: 10.1007/s00253-021-11406-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/07/2021] [Accepted: 06/08/2021] [Indexed: 12/25/2022]
Abstract
When microorganisms invade a host, the innate immune system first recognizes the pathogen-associated molecular patterns of these microorganisms through pattern recognition receptors (PRRs). Toll-like receptors (TLRs) are known transmembrane PRRs existing in both invertebrates and vertebrates. Upon ligand recognition, TLRs initiate a cascade of signaling events; promote the pro-inflammatory cytokine, type I interferon, and chemokine expression; and play an essential role in the modulation of the host’s innate and adaptive immunity. Therefore, it is of great significance to improve our understanding of antimicrobial immune responses by studying the role of TLRs and their signal molecules in the host’s defense against invading microbes. This paper aims to summarize the specificity of TLRs in recognition of conserved microbial components, such as lipoprotein, lipopolysaccharide, flagella, endosomal nucleic acids, and other bioactive metabolites derived from microbes. This set of interactions helps to elucidate the immunomodulatory effect of TLRs and the signal transduction changes involved in the infectious process and provide a novel therapeutic strategy to combat microbial infections.
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49
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González LA, Melo-González F, Sebastián VP, Vallejos OP, Noguera LP, Suazo ID, Schultz BM, Manosalva AH, Peñaloza HF, Soto JA, Parker D, Riedel CA, González PA, Kalergis AM, Bueno SM. Characterization of the Anti-Inflammatory Capacity of IL-10-Producing Neutrophils in Response to Streptococcus pneumoniae Infection. Front Immunol 2021; 12:638917. [PMID: 33995357 PMCID: PMC8113954 DOI: 10.3389/fimmu.2021.638917] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/06/2021] [Indexed: 12/14/2022] Open
Abstract
Neutrophils are immune cells classically defined as pro-inflammatory effector cells. However, current accumulated evidence indicates that neutrophils have more versatile immune-modulating properties. During acute lung infection with Streptococcus pneumoniae in mice, interleukin-10 (IL-10) production is required to temper an excessive lung injury and to improve survival, yet the cellular source of IL-10 and the immunomodulatory role of neutrophils during S. pneumoniae infection remain unknown. Here we show that neutrophils are the main myeloid cells that produce IL-10 in the lungs during the first 48 h of infection. Importantly, in vitro assays with bone-marrow derived neutrophils confirmed that IL-10 can be induced by these cells by the direct recognition of pneumococcal antigens. In vivo, we identified the recruitment of two neutrophil subpopulations in the lungs following infection, which exhibited clear morphological differences and a distinctive profile of IL-10 production at 48 h post-infection. Furthermore, adoptive transfer of neutrophils from WT mice into IL-10 knockout mice (Il10-/-) fully restored IL-10 production in the lungs and reduced lung histopathology. These results suggest that IL-10 production by neutrophils induced by S. pneumoniae limits lung injury and is important to mediate an effective immune response required for host survival.
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Affiliation(s)
- Liliana A González
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Felipe Melo-González
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Valentina P Sebastián
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Omar P Vallejos
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Loreani P Noguera
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Isidora D Suazo
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Bárbara M Schultz
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Andrés H Manosalva
- Servicio de Anatomía Patológica, Hospital Barros Luco Trudeau, Santiago, Chile
| | - Hernán F Peñaloza
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jorge A Soto
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Dane Parker
- Department of Pathology, Immunology and Laboratory Medicine, Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Newark, NJ, United States
| | - Claudia A Riedel
- Millennium Institute on Immunology and Immunotherapy, Departamento de Biología Celular, Facultad de Ciencias Biológicas y Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile
| | - Pablo A González
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alexis M Kalergis
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Susan M Bueno
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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50
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Staphylococcus aureus lipoproteins promote abscess formation in mice, shielding bacteria from immune killing. Commun Biol 2021; 4:432. [PMID: 33785850 PMCID: PMC8010101 DOI: 10.1038/s42003-021-01947-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 03/02/2021] [Indexed: 12/27/2022] Open
Abstract
Despite being a major bacterial factor in alerting the human immune system, the role of Staphylococcus aureus (S. aureus) lipoproteins (Lpp) in skin infections remains largely unknown. Here, we demonstrated that subcutaneous injection of S. aureus Lpp led to infiltration of neutrophils and monocytes/macrophages and induced skin lesions in mice. Lipid-moiety of S. aureus Lpp and host TLR2 was responsible for such effect. Lpp-deficient S. aureus strains exhibited smaller lesion size and reduced bacterial loads than their parental strains; the altered phenotype in bacterial loads was TLR2-independent. Lpp expression in skin infections contributed to imbalanced local hemostasis toward hypercoagulable state. Depletion of leukocytes or fibrinogen abrogated the effects induced by Lpp in terms of skin lesions and bacterial burden. Our data suggest that S. aureus Lpp induce skin inflammation and promote abscess formation that protects bacteria from innate immune killing. This suggests an intriguing bacterial immune evasion mechanism. Mohammad et al. show that subcutaneous injection of Staphylococcus aureus lipoproteins (Lpp) leads to the infiltration of neutrophils and monocytes/macrophages, inducing skin lesions in mice. They find that S. aureus Lpp promotes abscess formation, which protects bacteria from innate immune killing, suggesting an intriguing bacterial immune evasion mechanism.
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