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Ye J, Qi X. Vaginal microecology and its role in human papillomavirus infection and human papillomavirus associated cervical lesions. APMIS 2023. [PMID: 37941500 DOI: 10.1111/apm.13356] [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: 06/25/2023] [Accepted: 10/23/2023] [Indexed: 11/10/2023]
Abstract
The vaginal microecology comprises the vaginal microbiome, immune microenvironment, vaginal anatomy, and the cervicovaginal fluid, which is rich in metabolites, enzymes, and cytokines. Investigating its role in the female reproductive system holds paramount significance. The advent of next-generation sequencing enabled a more profound investigation into the structure of the vaginal microbial community in relation to the female reproductive system. Human papillomavirus infection is prevalent among women of reproductive age, and persistent oncogenic HPV infection is widely recognized as a factor associated with cervical cancer. Extensive previous research has demonstrated that dysbiosis of vaginal microbiota characterized by a reduction in Lactobacillus species, heightens susceptivity to HPV infection, consequently contributing to persistent HPV infection and the progression of cervical lesion. Likewise, HPV infection can exacerbate dysbiosis. This review aims to provide a comprehensive summary of current literatures and to elucidate potential mechanisms underlying the interaction between vaginal microecology and HPV infection, with the intention of offering valuable insights for future clinical interventions.
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Affiliation(s)
- Jiatian Ye
- Department of Gynecology and Obstetrics, Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, West China Second Hospital, Sichuan University, Chengdu, China
| | - Xiaorong Qi
- Department of Gynecology and Obstetrics, Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, West China Second Hospital, Sichuan University, Chengdu, China
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2
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Shahi I, Dongas SA, Ilmain JK, Torres VJ, Ratner AJ. Characterization of tigurilysin, a novel human CD59-specific cholesterol-dependent cytolysin, reveals a role for host specificity in augmenting toxin activity. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001393. [PMID: 37702594 PMCID: PMC10569062 DOI: 10.1099/mic.0.001393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/05/2023] [Indexed: 09/14/2023]
Abstract
Cholesterol-dependent cytolysins (CDCs) are a large family of pore-forming toxins, produced by numerous Gram-positive pathogens. CDCs depend on host membrane cholesterol for pore formation; some CDCs also require surface-associated human CD59 (hCD59) for binding, conferring specificity for human cells. We purified a recombinant version of a putative CDC encoded in the genome of Streptococcus oralis subsp. tigurinus, tigurilysin (TGY), and used CRISPR/Cas9 to construct hCD59 knockout (KO) HeLa and JEG-3 cell lines. Cell viability assays with TGY on wild-type and hCD59 KO cells showed that TGY is a hCD59-dependent CDC. Two variants of TGY exist among S. oralis subsp. tigurinus genomes, only one of which is functional. We discovered that a single amino acid change between these two TGY variants determines its activity. Flow cytometry and oligomerization Western blots revealed that the single amino acid difference between the two TGY isoforms disrupts host cell binding and oligomerization. Furthermore, experiments with hCD59 KO cells and cholesterol-depleted cells demonstrated that TGY is fully dependent on both hCD59 and cholesterol for activity, unlike other known hCD59-dependent CDCs. Using full-length CDCs and toxin constructs differing only in the binding domain, we determined that having hCD59 dependence leads to increased lysis efficiency, conferring a potential advantage to organisms producing hCD59-dependent CDCs.
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Affiliation(s)
- Ifrah Shahi
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY, USA
| | - Sophia A. Dongas
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY, USA
| | - Juliana K. Ilmain
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Victor J. Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Adam J. Ratner
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
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3
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Shahi I, Dongas SA, Ilmain JK, Torres VJ, Ratner AJ. Characterization of Tigurilysin, a Novel Human CD59-Specific Cholesterol-Dependent Cytolysin, Reveals a Role for Host Specificity in Augmenting Toxin Activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.21.545930. [PMID: 37546867 PMCID: PMC10401958 DOI: 10.1101/2023.06.21.545930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Cholesterol dependent cytolysins (CDCs) are a large family of pore forming toxins, produced by numerous gram-positive pathogens. CDCs depend on host membrane cholesterol for pore formation; some CDCs also require surface associated human CD59 (hCD59) for binding, conferring specificity for human cells. We purified a recombinant version of a putative CDC encoded in the genome of Streptococcus oralis subsp. tigurinus , tigurilysin (TGY), and used CRISPR/Cas9 to construct hCD59 knockout (KO) HeLa and JEG-3 cell lines. Cell viability assays with TGY on WT and hCD59 KO cells showed that TGY is a hCD59-dependent CDC. Two variants of TGY exist among S. oralis subsp. tigurinus genomes, only one of which is functional. We discovered that a single amino acid change between these two TGY variants determines its activity. Flow cytometry and oligomerization western blots revealed that the single amino acid difference between the two TGY isoforms disrupts host cell binding and oligomerization. Furthermore, experiments with hCD59 KO cells and cholesterol depleted cells demonstrated that TGY is fully dependent on both hCD59 and cholesterol for activity, unlike other known hCD59-dependent CDCs. Using full-length CDCs and toxin constructs differing only in the binding domain, we determined that having hCD59-dependence leads to increased lysis efficiency, conferring a potential advantage to organisms producing hCD59-dependent CDCs. IMPORTANCE Cholesterol dependent cytolysins (CDCs) are produced by a variety of disease-causing bacteria, and may play a significant role in pathogenesis. Understanding CDC mechanisms of action provides useful information for developing anti-virulence strategies against bacteria that utilize CDCs and other pore-forming toxins in pathogenesis. This study describes for the first time a novel human-specific CDC with an atypical pore forming mechanism compared to known CDCs. In addition, this study demonstrates that human-specificity potentially confers increased lytic efficiency to CDCs. These data provide a possible explanation for the selective advantage of developing hCD59-dependency in CDCs and the consequent host restriction.
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Affiliation(s)
- Ifrah Shahi
- New York University Grossman School of Medicine, Department of Pediatrics, New York, NY
| | - Sophia A. Dongas
- New York University Grossman School of Medicine, Department of Pediatrics, New York, NY
| | - Juliana K. Ilmain
- New York University Grossman School of Medicine, Department of Microbiology, New York, NY
| | - Victor J. Torres
- New York University Grossman School of Medicine, Department of Microbiology, New York, NY
| | - Adam J. Ratner
- New York University Grossman School of Medicine, Department of Pediatrics, New York, NY
- New York University Grossman School of Medicine, Department of Microbiology, New York, NY
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4
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Tomoyasu T, Matsumoto A, Takao A, Tabata A, Nagamune H. A simple method to differentiate three classes of cholesterol-dependent cytolysins. J Microbiol Methods 2023; 207:106696. [PMID: 36898586 DOI: 10.1016/j.mimet.2023.106696] [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: 01/05/2023] [Revised: 03/06/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023]
Abstract
Cholesterol-dependent cytolysins (CDCs) are proteinaceous toxins widely distributed in gram-positive pathogenic bacteria. CDCs can be classified into three groups (I-III) based on the mode of receptor recognition. Group I CDCs recognize cholesterol as their receptor. Group II CDC specifically recognizes human CD59 as the primary receptor on the cell membrane. Only intermedilysin from Streptococcus intermedius has been reported as a group II CDC. Group III CDCs recognize both human CD59 and cholesterol as receptors. CD59 contains five disulfide bridges in its tertiary structure. Therefore, we treated human erythrocytes with dithiothreitol (DTT) to inactivate CD59 on membranes. Our data showed that DTT treatment caused a complete loss of recognition of intermedilysin and an anti-human CD59 monoclonal antibody. In contrast, this treatment did not affect the recognition of group I CDCs, judging from the fact that DTT-treated erythrocytes were lysed with the same efficiency as mock-treated human erythrocytes. The recognition of group III CDCs toward DTT-treated erythrocytes was partially reduced, and these results are likely due to the loss of human CD59 recognition. Therefore, the degree of human CD59 and cholesterol requirements of uncharacterized group III CDCs frequently found in Mitis group streptococci can be easily estimated by comparing the amounts of hemolysis between DTT-treated and mock-treated erythrocytes.
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Affiliation(s)
- Toshifumi Tomoyasu
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, Tokushima, Japan; Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan
| | - Airi Matsumoto
- Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan
| | - Ayuko Takao
- Department of Oral Microbiology, School of Dental Medicine, Tsurumi University, Yokohama, Kanagawa, Japan
| | - Atsushi Tabata
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, Tokushima, Japan; Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan
| | - Hideaki Nagamune
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, Tokushima, Japan; Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan.
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5
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Pawley DC, Dikici E, Deo SK, Raccamarich P, Fischl MA, Alcaide M, Daunert S. Rapid Point-of-Care Test Kit for Bacterial Vaginosis: Detection of Vaginolysin and Clue Cells Using Paper Strips and a Smartphone. Anal Chem 2022; 94:11619-11626. [PMID: 35943181 DOI: 10.1021/acs.analchem.2c02094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There is an unmet need for a point-of-care test that is accurate, affordable, and simple to diagnose bacterial vaginosis, the most common cause of vaginal symptoms among women. Bacterial vaginosis leaves patients with undesirable vaginal discharge, malodor, and discomfort. Currently, the diagnosis of bacterial vaginosis is inaccurate and complex, leading to high rates of misdiagnosis. Inaccurate diagnoses are unsafe as bacterial vaginosis increases the risks of acquiring sexually transmitted infections as well as the likelihood of miscarriages. To date, the most commonly identified bacteria associated with bacterial vaginosis is Gardnerella vaginalis. We developed a method for the expression, purification, and detection of vaginolysin, the most well-characterized virulence factor of G. vaginalis. Elevated levels of G. vaginalis have been shown to lead to a toxic vaginal environment, facilitating bacterial vaginosis. We have developed an enzyme-linked immunosorbent assay for the detection of vaginolysin, which was translated to a lateral flow assay for use in a rapid, straightforward, cost-effective paper-based diagnostic test for vaginolysin that does not require the use of instrumentation. In conjunction, we have employed a commercially available smartphone microscopy kit to visualize clue cells without the need for equipment or electricity. The combination of these methodologies allows for an accurate and easy approach to diagnose bacterial vaginosis with minimal resources for use in any setting.
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Affiliation(s)
- Devon C Pawley
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida 33136, United States.,Dr. JT Macdonald Foundation Biomedical Nanotechnology Institute of the University of Miami, Miami, Florida 33136, United States
| | - Emre Dikici
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida 33136, United States.,Dr. JT Macdonald Foundation Biomedical Nanotechnology Institute of the University of Miami, Miami, Florida 33136, United States
| | - Sapna K Deo
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida 33136, United States.,Dr. JT Macdonald Foundation Biomedical Nanotechnology Institute of the University of Miami, Miami, Florida 33136, United States
| | - Patricia Raccamarich
- Division of Infectious Diseases, Miller School of Medicine, University of Miami, Miami, Florida 33136, United States
| | - Margaret A Fischl
- Division of Infectious Diseases, Miller School of Medicine, University of Miami, Miami, Florida 33136, United States
| | - Maria Alcaide
- Division of Infectious Diseases, Miller School of Medicine, University of Miami, Miami, Florida 33136, United States
| | - Sylvia Daunert
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida 33136, United States.,Dr. JT Macdonald Foundation Biomedical Nanotechnology Institute of the University of Miami, Miami, Florida 33136, United States.,University of Miami Clinical and Translational Science Institute, Miller School of Medicine, University of Miami, Miami, Florida 33136, United States
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6
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Qin H, Xiao B. Research Progress on the Correlation Between Gardnerella Typing and Bacterial Vaginosis. Front Cell Infect Microbiol 2022; 12:858155. [PMID: 35402309 PMCID: PMC8990036 DOI: 10.3389/fcimb.2022.858155] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 03/01/2022] [Indexed: 11/17/2022] Open
Abstract
Bacterial vaginosis (BV) is the most common infectious disease of the reproductive tract in women of childbearing age. It often manifests as an imbalance in the vaginal microbiome, including a decrease in Lactobacillus and an increase in anaerobic bacteria. While Gardnerella spp. are considered a major cause of BV, they are also detected in the vaginal microbiome of healthy women. G. vaginalis was the only recognized species of Gardnerella until a recent study characterized three new species, G. leopoldii, G. piotii, and G. swidsinskii. This review describes the different types and genetic diversity of Gardnerella, as well as new findings on the correlation between different Gardnerella spp. and BV.
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Mondal AK, Chattopadhyay K. Structures and functions of the membrane-damaging pore-forming proteins. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 128:241-288. [PMID: 35034720 DOI: 10.1016/bs.apcsb.2021.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Pore-forming proteins (PFPs) of the diverse life forms have emerged as the potent cell-killing entities owing to their specialized membrane-damaging properties. PFPs have the unique ability to perforate the plasma membranes of their target cells, and they exert this functionality by creating oligomeric pores in the membrane lipid bilayer. Pathogenic bacteria employ PFPs as toxins to execute their virulence mechanisms, whereas in the higher vertebrates PFPs are deployed as the part of the immune system and to generate inflammatory responses. PFPs are the unique dimorphic proteins that are generally synthesized as water-soluble molecules, and transform into membrane-inserted oligomeric pore assemblies upon interacting with the target membranes. In spite of sharing very little sequence similarity, PFPs from diverse organisms display incredible structural similarity. Yet, at the same time, structure-function mechanisms of the PFPs document remarkable versatility. Such notions establish PFPs as the fascinating model system to explore variety of unsolved issues pertaining to the structure-function paradigm of the proteins that interact and act in the membrane environment. In this article, we discuss our current understanding regarding the structural basis of the pore-forming functions of the diverse class of PFPs. We attempt to highlight the similarities and differences in their structures, membrane pore-formation mechanisms, and their implications for the various biological processes, ranging from the bacterial virulence mechanisms to the inflammatory immune response generation in the higher animals.
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Affiliation(s)
- Anish Kumar Mondal
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Kausik Chattopadhyay
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India.
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8
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Chen X, Lu Y, Chen T, Li R. The Female Vaginal Microbiome in Health and Bacterial Vaginosis. Front Cell Infect Microbiol 2021; 11:631972. [PMID: 33898328 PMCID: PMC8058480 DOI: 10.3389/fcimb.2021.631972] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 03/19/2021] [Indexed: 12/11/2022] Open
Abstract
The vaginal microbiome is an intricate and dynamic microecosystem that constantly undergoes fluctuations during the female menstrual cycle and the woman’s entire life. A healthy vaginal microbiome is dominated by Lactobacillus which produce various antimicrobial compounds. Bacterial vaginosis (BV) is characterized by the loss or sharp decline in the total number of Lactobacillus and a corresponding marked increase in the concentration of anaerobic microbes. BV is a highly prevalent disorder of the vaginal microbiota among women of reproductive age globally. BV is confirmed to be associated with adverse gynecologic and obstetric outcomes, such as sexually transmitted infections, pelvic inflammatory disease, and preterm birth. Gardnerella vaginalis is the most common microorganism identified from BV. It is the predominant microbe in polymicrobial biofilms that could shelter G. vaginalis and other BV-associated microbes from adverse host environments. Many efforts have been made to increase our understanding of the vaginal microbiome in health and BV. Thus, improved novel and accurate diagnosis and therapeutic strategies for BV have been developed. This review covers the features of vaginal microbiome, BV, BV-associated diseases, and various strategies of diagnosis and treatment of BV, with an emphasis on recent research progresses.
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Affiliation(s)
- Xiaodi Chen
- Department of Clinical Laboratory, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Yune Lu
- Department of Clinical Laboratory, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Tao Chen
- Department of Clinical Laboratory, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Rongguo Li
- Department of Clinical Laboratory, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan, China
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Gardnerella vaginalis Vaginolysin (VLY)-Derived MAP8 Peptide (VLY-MAP8) Induced the Production of Egg Yolk IgY Antibodies that Inhibit Erythrocytes Lysis. Int J Pept Res Ther 2021. [DOI: 10.1007/s10989-020-10099-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Atopobium vaginae and Prevotella bivia Are Able to Incorporate and Influence Gene Expression in a Pre-Formed Gardnerella vaginalis Biofilm. Pathogens 2021; 10:pathogens10020247. [PMID: 33672647 PMCID: PMC7924186 DOI: 10.3390/pathogens10020247] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 12/12/2022] Open
Abstract
Bacterial vaginosis (BV) is associated with a highly structured polymicrobial biofilm on the vaginal epithelium where Gardnerella species presumably play a pivotal role. Gardnerella vaginalis, Atopobium vaginae, and Prevotella bivia are vaginal pathogens detected during the early stages of incident BV. Herein, we aimed to analyze the impact of A. vaginae and P. bivia on a pre-established G. vaginalis biofilm using a novel in vitro triple-species biofilm model. Total biofilm biomass was determined by the crystal violet method. We also discriminated the bacterial populations in the biofilm and in its planktonic fraction by using PNA FISH. We further analyzed the influence of A. vaginae and P. bivia on the expression of key virulence genes of G. vaginalis by quantitative PCR. In our tested conditions, A. vaginae and P. bivia were able to incorporate into pre-established G. vaginalis biofilms but did not induce an increase in total biofilm biomass, when compared with 48-h G. vaginalis biofilms. However, they were able to significantly influence the expression of HMPREF0424_0821, a gene suggested to be associated with biofilm maintenance in G. vaginalis. This study suggests that microbial relationships between co-infecting bacteria can deeply affect the G. vaginalis biofilm, a crucial marker of BV.
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Drabavicius G, Daelemans D. Intermedilysin cytolytic activity depends on heparan sulfates and membrane composition. PLoS Genet 2021; 17:e1009387. [PMID: 33577603 PMCID: PMC7906465 DOI: 10.1371/journal.pgen.1009387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 02/25/2021] [Accepted: 01/27/2021] [Indexed: 12/26/2022] Open
Abstract
Cholesterol-dependent cytolysins (CDCs), of which intermedilysin (ILY) is an archetypal member, are a group of pore-forming toxins secreted by a large variety of pathogenic bacteria. These toxins, secreted as soluble monomers, oligomerize upon interaction with cholesterol in the target membrane and transect it as pores of diameters of up to 100 to 300 Å. These pores disrupt cell membranes and result in cell lysis. The immune receptor CD59 is a well-established cellular factor required for intermedilysin pore formation. In this study, we applied genome-wide CRISPR-Cas9 knock-out screening to reveal additional cellular co-factors essential for ILY-mediated cell lysis. We discovered a plethora of genes previously not associated with ILY, many of which are important for membrane constitution. We show that heparan sulfates facilitate ILY activity, which can be inhibited by heparin. Furthermore, we identified hits in both protein and lipid glycosylation pathways and show a role for glucosylceramide, demonstrating that membrane organization is important for ILY activity. We also cross-validated identified genes with vaginolysin and pneumolysin and found that pneumolysin's cytolytic activity strongly depends on the asymmetric distribution of membrane phospholipids. This study shows that membrane-targeting toxins combined with genetic screening can identify genes involved in biological membrane composition and metabolism.
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Affiliation(s)
- Gediminas Drabavicius
- KU Leuven Department of Microbiology, Immunology, and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute, Leuven, Belgium
- Vilnius University, Life Sciences Center, Institute of Biotechnology, Vilnius, Lithuania
| | - Dirk Daelemans
- KU Leuven Department of Microbiology, Immunology, and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute, Leuven, Belgium
- * E-mail:
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12
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Li Y, Li Y, Mengist HM, Shi C, Zhang C, Wang B, Li T, Huang Y, Xu Y, Jin T. Structural Basis of the Pore-Forming Toxin/Membrane Interaction. Toxins (Basel) 2021; 13:toxins13020128. [PMID: 33572271 PMCID: PMC7914777 DOI: 10.3390/toxins13020128] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/13/2021] [Accepted: 02/02/2021] [Indexed: 12/14/2022] Open
Abstract
With the rapid growth of antibiotic-resistant bacteria, it is urgent to develop alternative therapeutic strategies. Pore-forming toxins (PFTs) belong to the largest family of virulence factors of many pathogenic bacteria and constitute the most characterized classes of pore-forming proteins (PFPs). Recent studies revealed the structural basis of several PFTs, both as soluble monomers, and transmembrane oligomers. Upon interacting with host cells, the soluble monomer of bacterial PFTs assembles into transmembrane oligomeric complexes that insert into membranes and affect target cell-membrane permeability, leading to diverse cellular responses and outcomes. Herein we have reviewed the structural basis of pore formation and interaction of PFTs with the host cell membrane, which could add valuable contributions in comprehensive understanding of PFTs and searching for novel therapeutic strategies targeting PFTs and interaction with host receptors in the fight of bacterial antibiotic-resistance.
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Affiliation(s)
- Yajuan Li
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
| | - Yuelong Li
- Hefei National Laboratory for Physical Sciences at Microscale, Laboratory of Structural Immunology, CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China; (Y.L.); (H.M.M.); (C.Z.)
| | - Hylemariam Mihiretie Mengist
- Hefei National Laboratory for Physical Sciences at Microscale, Laboratory of Structural Immunology, CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China; (Y.L.); (H.M.M.); (C.Z.)
| | - Cuixiao Shi
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
| | - Caiying Zhang
- Hefei National Laboratory for Physical Sciences at Microscale, Laboratory of Structural Immunology, CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China; (Y.L.); (H.M.M.); (C.Z.)
| | - Bo Wang
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
| | - Tingting Li
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
| | - Ying Huang
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
| | - Yuanhong Xu
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; (Y.L.); (C.S.); (B.W.); (T.L.); (Y.H.)
- Correspondence: (Y.X.); (T.J.); Tel.: +86-13505694447 (Y.X.); +86-17605607323 (T.J.)
| | - Tengchuan Jin
- Hefei National Laboratory for Physical Sciences at Microscale, Laboratory of Structural Immunology, CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China; (Y.L.); (H.M.M.); (C.Z.)
- Correspondence: (Y.X.); (T.J.); Tel.: +86-13505694447 (Y.X.); +86-17605607323 (T.J.)
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13
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Sequence Comparison of Vaginolysin from Different Gardnerella Species. Pathogens 2021; 10:pathogens10020086. [PMID: 33498226 PMCID: PMC7909246 DOI: 10.3390/pathogens10020086] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/07/2021] [Accepted: 01/14/2021] [Indexed: 01/21/2023] Open
Abstract
Gardnerella vaginalis has recently been split into 13 distinct species. In this study, we tested the hypotheses that species-specific variations in the vaginolysin (VLY) amino acid sequence could influence the interaction between the toxin and vaginal epithelial cells and that VLY variation may be one factor that distinguishes less virulent or commensal strains from more virulent strains. This was assessed by bioinformatic analyses of publicly available Gardnerella spp. sequences and quantification of cytotoxicity and cytokine production from purified, recombinantly produced versions of VLY. After identifying conserved differences that could distinguish distinct VLY types, we analyzed metagenomic data from a cohort of female subjects from the Vaginal Human Microbiome Project to investigate whether these different VLY types exhibited any significant associations with symptoms or Gardnerella spp.-relative abundance in vaginal swab samples. While Type 1 VLY was most prevalent among the subjects and may be associated with increased reports of symptoms, subjects with Type 2 VLY dominant profiles exhibited increased relative Gardnerella spp. abundance. Our findings suggest that amino acid differences alter the interaction of VLY with vaginal keratinocytes, which may potentiate differences in bacterial vaginosis (BV) immunopathology in vivo.
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14
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Penkauskas T, Zentelyte A, Ganpule S, Valincius G, Preta G. Pleiotropic effects of statins via interaction with the lipid bilayer: A combined approach. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183306. [DOI: 10.1016/j.bbamem.2020.183306] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/18/2020] [Accepted: 04/07/2020] [Indexed: 12/25/2022]
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15
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Interaction of Macrophages and Cholesterol-Dependent Cytolysins: The Impact on Immune Response and Cellular Survival. Toxins (Basel) 2020; 12:toxins12090531. [PMID: 32825096 PMCID: PMC7551085 DOI: 10.3390/toxins12090531] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/13/2020] [Accepted: 08/15/2020] [Indexed: 02/07/2023] Open
Abstract
Cholesterol-dependent cytolysins (CDCs) are key virulence factors involved in many lethal bacterial infections, including pneumonia, necrotizing soft tissue infections, bacterial meningitis, and miscarriage. Host responses to these diseases involve myeloid cells, especially macrophages. Macrophages use several systems to detect and respond to cholesterol-dependent cytolysins, including membrane repair, mitogen-activated protein (MAP) kinase signaling, phagocytosis, cytokine production, and activation of the adaptive immune system. However, CDCs also promote immune evasion by silencing and/or destroying myeloid cells. While there are many common themes between the various CDCs, each CDC also possesses specific features to optimally benefit the pathogen producing it. This review highlights host responses to CDC pathogenesis with a focus on macrophages. Due to their robust plasticity, macrophages play key roles in the outcome of bacterial infections. Understanding the unique features and differences within the common theme of CDCs bolsters new tools for research and therapy.
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Kucinskaite-Kodze I, Simanavicius M, Dapkunas J, Pleckaityte M, Zvirbliene A. Mapping of Recognition Sites of Monoclonal Antibodies Responsible for the Inhibition of Pneumolysin Functional Activity. Biomolecules 2020; 10:biom10071009. [PMID: 32650398 PMCID: PMC7408604 DOI: 10.3390/biom10071009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/01/2020] [Accepted: 07/04/2020] [Indexed: 02/07/2023] Open
Abstract
The pathogenicity of many bacteria, including Streptococcus pneumoniae, depends on pore-forming toxins (PFTs) that cause host cell lysis by forming large pores in cholesterol-containing cell membranes. Therefore, PFTs-neutralising antibodies may provide useful tools for reducing S. pneumoniae pathogenic effects. This study aimed at the development and characterisation of monoclonal antibodies (MAbs) with neutralising activity to S. pneumoniae PFT pneumolysin (PLY). Five out of 10 produced MAbs were able to neutralise the cytolytic activity of PLY on a lung epithelial cell line. Epitope mapping with a series of recombinant overlapping PLY fragments revealed that neutralising MAbs are directed against PLY loops L1 and L3 within domain 4. The epitopes of MAbs 3A9, 6E5 and 12F11 located at L1 loop (aa 454–471) were crucial for PLY binding to the immobilised cholesterol. In contrast, the MAb 12D10 recognising L3 (aa 403–423) and the MAb 3F3 against the conformational epitope did not interfere with PLY-cholesterol interaction. Due to conformation-dependent binding, the approach to use overlapping peptides for fine epitope mapping of the neutralising MAbs was unsuccessful. Therefore, the epitopes recognised by the MAbs were analysed using computational methods. This study provides new data on PLY sites involved in functional activity.
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Castro J, Jefferson KK, Cerca N. Genetic Heterogeneity and Taxonomic Diversity among Gardnerella Species. Trends Microbiol 2020; 28:202-211. [DOI: 10.1016/j.tim.2019.10.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/27/2019] [Accepted: 10/08/2019] [Indexed: 12/17/2022]
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18
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Kalia N, Singh J, Kaur M. Microbiota in vaginal health and pathogenesis of recurrent vulvovaginal infections: a critical review. Ann Clin Microbiol Antimicrob 2020; 19:5. [PMID: 31992328 PMCID: PMC6986042 DOI: 10.1186/s12941-020-0347-4] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 01/22/2020] [Indexed: 12/13/2022] Open
Abstract
Recurrent vulvovaginal infections (RVVI) has not only become an epidemiological and clinical problem but also include large social and psychological consequences. Understanding the mechanisms of both commensalism and pathogenesis are necessary for the development of efficient diagnosis and treatment strategies for these enigmatic vaginal infections. Through this review, an attempt has been made to analyze vaginal microbiota (VMB) from scratch and to provide an update on its current understanding in relation to health and common RVVI i.e. bacterial vaginosis, vulvovaginal candidiaisis and Trichomoniasis, making the present review first of its kind. For this, potentially relevant studies were retrieved from data sources and critical analysis of the literature was made. Though, culture-independent methods have greatly unfolded the mystery regarding vaginal bacterial microbiome, there are only a few studies regarding the composition and diversity of vaginal mycobiome and different Trichomonas vaginalis strains. This scenario suggests a need of further studies based on comparative genomics of RVVI pathogens to improve our perceptive of RVVI pathogenesis that is still not clear (Fig. 5). Besides this, the review details the rationale for Lactobacilli dominance and changes that occur in healthy VMB throughout a women’s life. Moreover, the list of possible agents continues to expand and new species recognised in both health and VVI are updated in this review. The review concludes with the controversies challenging the widely accepted dogma i.e. “VMB dominated with Lactobacilli is healthier than a diverse VMB”. These controversies, over the past decade, have complicated the definition of vaginal health and vaginal infections with no definite conclusion. Thus, further studies on newly recognised microbial agents may reveal answers to these controversies. Conversely, VMB of women could be an answer but it is not enough to just look at the microbiology. We have to look at the woman itself, as VMB which is fine for one woman may be troublesome for others. These differences in women’s response to the same VMB may be determined by a permutation of behavioural, cultural, genetic and various other anonymous factors, exploration of which may lead to proper definition of vaginal health and disease.
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Affiliation(s)
- Namarta Kalia
- Department of Molecular Biology & Biochemistry, Guru Nanak Dev University, Amritsar, 143005, India
| | - Jatinder Singh
- Department of Molecular Biology & Biochemistry, Guru Nanak Dev University, Amritsar, 143005, India.
| | - Manpreet Kaur
- Department of Human Genetics, Guru Nanak Dev University, Amritsar, 143005, India.
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Pleckaityte M. Cholesterol-Dependent Cytolysins Produced by Vaginal Bacteria: Certainties and Controversies. Front Cell Infect Microbiol 2020; 9:452. [PMID: 31998661 PMCID: PMC6966277 DOI: 10.3389/fcimb.2019.00452] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/12/2019] [Indexed: 01/16/2023] Open
Abstract
Bacterial vaginosis (BV) is a vaginal anaerobic dysbiosis that affects women of reproductive age worldwide. BV is microbiologically characterized by the depletion of vaginal lactobacilli and the overgrowth of anaerobic bacterial species. Accumulated evidence suggests that Gardnerella spp. have a pivotal role among BV-associated bacteria in the initiation and development of BV. However, Gardnerella spp. often colonize healthy women. Lactobacillus iners is considered as a prevalent constituent of healthy vaginal microbiota, and is abundant in BV. Gardnerella spp. and L. iners secrete the toxins vaginolysin (VLY) and inerolysin (INY), which have structural and activity features attributed to cholesterol-dependent cytolysins (CDCs). CDCs are produced by many pathogenic bacteria as virulence factors that participate in various stages of disease progression by forming lytic and non-lytic pores in cell membranes or via pore-independent pathways. VLY is expressed in the majority of Gardnerella spp. isolates; less is known about the prevalence of the gene that encodes INY. INY is a classical CDC; membrane cholesterol acts a receptor for INY. VLY uses human CD59 as its receptor, although cholesterol remains indispensable for VLY pore-forming activity. INY-induced damage of artificial membranes is directly dependent on cholesterol concentration in the bilayer, whereas VLY-induced damage occurs with high levels of membrane cholesterol (>40 mol%). VLY primarily forms membrane-embedded complete rings in the synthetic bilayer, whereas INY forms arciform structures with smaller pore sizes. VLY activity is high at elevated pH, which is characteristic of BV, whereas INY activity is high at more acidic pH, which is specific for a healthy vagina. Increased VLY levels in vaginal mucosa in vivo were associated with clinical indicators of BV. However, experimental evidence is lacking for the specific roles of VLY and INY in BV. The interplay between vaginal bacterial species affects the expression of the gene encoding VLY, thereby modulating the virulence of Gardnerella spp. This review discusses the current evidence for VLY and INY cytolysins, including their structures and activities, factors affecting their expression, and their potential impacts on the progression of anaerobic dysbiosis.
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Affiliation(s)
- Milda Pleckaityte
- Laboratory of Immunology and Cell Biology, Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
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20
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Mohammadzadeh R, Sadeghi Kalani B, Kashanian M, Oshaghi M, Amirmozafari N. Prevalence of vaginolysin, sialidase and phospholipase genes in Gardnerella vaginalis isolates between bacterial vaginosis and healthy individuals. Med J Islam Repub Iran 2019; 33:85. [PMID: 31696079 PMCID: PMC6825396 DOI: 10.34171/mjiri.33.85] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Indexed: 01/01/2023] Open
Abstract
Background: Gardnerella vaginalis is considered as the predominant microorganism found in bacterial vaginosis (BV). The aim of this study was to evaluate the prevalence of virulence factors in G. vaginalis associated with BV or non-BV cases and their correlations with this disorder. Methods: A total of 102 vaginal specimens were collected from patients during their visit to Akbar Abadi hospital in Tehran, Iran. Bacterial vaginosis was determined by Nugent score and Amsel's criteria. Polymerase chain reaction (PCR) was used for the detection of G. vaginalis 16S rRNA, vaginolysin, sialidase and phospholipase genes. To evaluate the association between the presence of vly, pho, and sld genes and BV. Pearson Chi-square test was applied using SPSS software. P-value ≤0.05 was considered as significant. Results: Totally, 27.4% of the patients were suffering from BV. Gardnerella vaginalis was found in 100% women with BV and in 56.7% women with normal vaginal discharge. The prevalence of vly, sld and pho genes in BV-associated G. vaginalis was 10 (35.7%) (95% CI [0.18, 0.53]), 19 (67.8%) (95% CI [0.51, 0.85]) and 6 (21.4%) (95% CI [0.06, 0.37]), respectively. The prevalence of the aforementioned genes in non-BV associated G. vaginalis was 20 (47.6%) (95% CI [0.33, 0.63]), 28 (66.6%) (95% CI [0.52, 0.81]), and 5 (11.9%) (95% CI [0.02, 0.22]), respectively. Our results showed no statistically significant association between the presence of the virulence genes and BV associatedness of this microorganism. Conclusion: Our results showed the presence of G. vaginalis in all BV patients and relatively high prevalence in healthy individuals. The prevalence rates of the three virulence genes were different in BV and non-BV associated G. vaginalis; however, the differences were not statistically significant.
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Affiliation(s)
- Rokhsareh Mohammadzadeh
- Microbial Biotechnology Research Center, Iran University of Medical Sciences, Tehran, Iran
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Behrooz Sadeghi Kalani
- Microbial Biotechnology Research Center, Iran University of Medical Sciences, Tehran, Iran
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Maryam Kashanian
- Department of Obstetrics and Gynecology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mojgan Oshaghi
- Department of Laboratory Sciences, School of Allied Health, Iran University of Medical Sciences, Tehran, Iran
| | - Nour Amirmozafari
- Microbial Biotechnology Research Center, Iran University of Medical Sciences, Tehran, Iran
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
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21
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Inerolysin and vaginolysin, the cytolysins implicated in vaginal dysbiosis, differently impair molecular integrity of phospholipid membranes. Sci Rep 2019; 9:10606. [PMID: 31337831 PMCID: PMC6650466 DOI: 10.1038/s41598-019-47043-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 07/09/2019] [Indexed: 02/07/2023] Open
Abstract
The pore-forming toxins, inerolysin (INY) and vaginolysin (VLY), produced by vaginal bacteria Lactobacillus iners and Gardnerella vaginalis were studied using the artificial cholesterol-rich tethered bilayer membranes (tBLMs) by electrochemical techniques. The electrochemical impedance spectroscopy (EIS) of tBLMs attested for the toxin-induced impairment of the integrity of phospholipid membranes. This observation was in line with the atomic force microscopy data demonstrating formation of oligomeric protein assemblies in tBLMs. These assemblies exhibited different morphologies: VLY mostly formed complete rings, whereas INY produced arciform structures. We found that both EIS (membrane damage) and the surface plasmon resonance (protein binding) data obtained on tBLMs are in-line with the data obtained in human cell lysis experiments. EIS, however, is capable of capturing effects inaccessible for biological activity assays. Specifically, we found that the INY-induced damage of tBLMs is nearly a linear function of membrane cholesterol content, whereas VLY triggered significant damage only at high (50 mol%) cholesterol concentrations. The observed differences of INY and VLY activities on phospholipid membranes might have clinical importance: both toxin-producing bacteria have been found in healthy vagina and dysbiosis, suggesting the need for adaptation at different vaginal conditions. Our results broaden the possibilities of application of tBLMs in medical diagnostics.
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22
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Morton CJ, Sani MA, Parker MW, Separovic F. Cholesterol-Dependent Cytolysins: Membrane and Protein Structural Requirements for Pore Formation. Chem Rev 2019; 119:7721-7736. [DOI: 10.1021/acs.chemrev.9b00090] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Craig J. Morton
- Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Marc-Antoine Sani
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Michael W. Parker
- Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Parkville, Victoria 3010, Australia
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | - Frances Separovic
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
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23
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Interaction of Gardnerella vaginalis and Vaginolysin with the Apical versus Basolateral Face of a Three-Dimensional Model of Vaginal Epithelium. Infect Immun 2019; 87:IAI.00646-18. [PMID: 30692180 DOI: 10.1128/iai.00646-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 01/21/2019] [Indexed: 12/17/2022] Open
Abstract
Studies have implicated Gardnerella vaginalis as an important etiological agent in bacterial vaginosis (BV). It produces a cholesterol-dependent cytolysin, vaginolysin (VLY). In this study, we sought to characterize the interaction between vaginal epithelium, G. vaginalis, and VLY using EpiVaginal tissues from MatTek. These tissues are three-dimensional and have distinct apical and basolateral sides, enabling comparison of the effects of G. vaginalis and VLY following exposure to either side. We measured cytotoxicity, cytokine production, and bacterial growth, following apical versus basolateral exposure. G. vaginalis exhibited more-rapid growth in coculture with the tissue model when it was exposed to the apical side. VLY permeabilized cells on the basolateral side of the tissues but failed to permeabilize apical epithelial cells. Cytokine secretion in response to VLY and G. vaginalis also depended on the polarity of exposure. VLY did not cause significant changes in cytokine levels when exposed apically. Apical tissue challenge by G. vaginalis appeared to dampen the inflammatory response, as decreases in granulocyte-macrophage colony-stimulating factor (GM-CSF) (6.6-fold), RANTES (14.8-fold), and interferon gamma inducible protein 10 kDa (IP-10) (53-fold) and an increase in interleukin-1 receptor antagonist (IL-1ra) (5-fold) were observed. In vivo, G. vaginalis normally colonizes the apical face of the vaginal epithelium. Results from this study suggest that while G. vaginalis may grow on the apical face of the vaginal epithelium, its VLY toxin does not target these cells in this model. This phenomenon could have important implications regarding colonization of the vagina by G. vaginalis and may suggest an explanation for the lack of an overt immune response to this organism.
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24
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Christie MP, Johnstone BA, Tweten RK, Parker MW, Morton CJ. Cholesterol-dependent cytolysins: from water-soluble state to membrane pore. Biophys Rev 2018; 10:1337-1348. [PMID: 30117093 DOI: 10.1007/s12551-018-0448-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 08/07/2018] [Indexed: 12/22/2022] Open
Abstract
The cholesterol-dependent cytolysins (CDCs) are a family of bacterial toxins that are important virulence factors for a number of pathogenic Gram-positive bacterial species. CDCs are secreted as soluble, stable monomeric proteins that bind specifically to cholesterol-rich cell membranes, where they assemble into well-defined ring-shaped complexes of around 40 monomers. The complex then undergoes a concerted structural change, driving a large pore through the membrane, potentially lysing the target cell. Understanding the details of this process as the protein transitions from a discrete monomer to a complex, membrane-spanning protein machine is an ongoing challenge. While many of the details have been revealed, there are still questions that remain unanswered. In this review, we present an overview of some of the key features of the structure and function of the CDCs, including the structure of the secreted monomers, the process of interaction with target membranes, and the transition from bound monomers to complete pores. Future directions in CDC research and the potential of CDCs as research tools will also be discussed.
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Affiliation(s)
- Michelle P Christie
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Bronte A Johnstone
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Rodney K Tweten
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Michael W Parker
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia.
- Australian Cancer Research Foundation Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia.
| | - Craig J Morton
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia.
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25
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Janulaitiene M, Gegzna V, Baranauskiene L, Bulavaitė A, Simanavicius M, Pleckaityte M. Phenotypic characterization of Gardnerella vaginalis subgroups suggests differences in their virulence potential. PLoS One 2018; 13:e0200625. [PMID: 30001418 PMCID: PMC6042761 DOI: 10.1371/journal.pone.0200625] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 06/29/2018] [Indexed: 11/30/2022] Open
Abstract
The well-known genotypic and phenotypic diversity of G. vaginalis resulted in its classification into at least four subgroups (clades) with diverse genomic properties. To evaluate the virulence potential of G. vaginalis subgroups, we analyzed the virulence-related phenotypic characteristics of 14 isolates of clade 1, 12 isolates of clade 2, 8 isolates of clade 4 assessing their in vitro ability to grow as a biofilm, produce the toxin vaginolysin, and express sialidase activity. Significant differences in VLY production were found (p = 0.023), but further analysis of clade pairs did not confirm this finding. The amount of biofim did not differ significantly among the clades. Analysis of sialidase activity indicated statistically significant differences among the clades (p < 0.001). Production of active recombinant G. vaginalis sialidase demonstrated the link between the sld gene and enzymatic activity, which may be differentially regulated at the transcriptional level. Statistical classification analysis (random forests algorithm) showed that G. vaginalis clades could be best defined by the profiles of two phenotypic characteristics: sialidase activity and vaginolysin production. The results of principal component analysis and hierarchical clustering suggested that all isolates can be subgrouped into three clusters, the structures of which are determined based on phenotypic characteristics of the isolates. Clade 4 was the most homogenous group, as all isolates were found in the same cluster, which is characterized by low production of all studied virulence factors. Clade 2 isolates were mainly distributed between two clusters, whereas clade 1 isolates were found in all three clusters that were characterized by a distinct profile of phenotypic characteristics. Our findings suggest that G. vaginalis subgroups with different virulence potential might play distinct roles in vaginal microbiota.
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Affiliation(s)
- Migle Janulaitiene
- Institute of Biotechnology, Vilnius University, Vilnius, Lithuania
- National Public Health Surveillance Laboratory, Vilnius, Lithuania
| | - Vilmantas Gegzna
- Institute of Photonics and Nanotechnology, Vilnius University, Vilnius, Lithuania
- Institute of Biosciences, Vilnius University, Vilnius, Lithuania
| | | | - Aistė Bulavaitė
- Institute of Biotechnology, Vilnius University, Vilnius, Lithuania
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26
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Mucke HA. Drug Repurposing Patent Applications January–March 2018. Assay Drug Dev Technol 2018; 16:253-259. [DOI: 10.1089/adt.2018.29077.pq1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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27
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Mondal AK, Sreekumar A, Kundu N, Kathuria R, Verma P, Gandhi S, Chattopadhyay K. Structural Basis and Functional Implications of the Membrane Pore-Formation Mechanisms of Bacterial Pore-Forming Toxins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1112:281-291. [DOI: 10.1007/978-981-13-3065-0_19] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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28
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Dapkunas Z, Baranauskas A, Mickiene G, Pleckaityte M, Zvirblis G. Generation of dimeric single-chain antibodies neutralizing the cytolytic activity of vaginolysin. ELECTRON J BIOTECHN 2017. [DOI: 10.1016/j.ejbt.2017.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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29
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Lawrence SL, Gorman MA, Feil SC, Mulhern TD, Kuiper MJ, Ratner AJ, Tweten RK, Morton CJ, Parker MW. Structural Basis for Receptor Recognition by the Human CD59-Responsive Cholesterol-Dependent Cytolysins. Structure 2016; 24:1488-98. [PMID: 27499440 PMCID: PMC5320943 DOI: 10.1016/j.str.2016.06.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 06/15/2016] [Accepted: 06/20/2016] [Indexed: 11/23/2022]
Abstract
Cholesterol-dependent cytolysins (CDCs) are a family of pore-forming toxins that punch holes in the outer membrane of eukaryotic cells. Cholesterol serves as the receptor, but a subclass of CDCs first binds to human CD59. Here we describe the crystal structures of vaginolysin and intermedilysin complexed to CD59. These studies, together with small-angle X-ray scattering, reveal that CD59 binds to each at different, though overlapping, sites, consistent with molecular dynamics simulations and binding studies. The CDC consensus undecapeptide motif, which for the CD59-responsive CDCs has a proline instead of a tryptophan in the motif, adopts a strikingly different conformation between the structures; our data suggest that the proline acts as a selectivity switch to ensure CD59-dependent CDCs bind their protein receptor first in preference to cholesterol. The structural data suggest a detailed model of how these water-soluble toxins assemble as prepores on the cell surface.
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Affiliation(s)
- Sara L Lawrence
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Michael A Gorman
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Susanne C Feil
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Terrence D Mulhern
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Michael J Kuiper
- Victorian Life Sciences Computation Initiative, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Adam J Ratner
- Departments of Pediatrics and Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Rodney K Tweten
- Department of Microbiology and Immunology, University of Oklahoma, Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Craig J Morton
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Michael W Parker
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia.
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30
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Preta G, Jankunec M, Heinrich F, Griffin S, Sheldon IM, Valincius G. Tethered bilayer membranes as a complementary tool for functional and structural studies: The pyolysin case. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2070-2080. [PMID: 27211243 DOI: 10.1016/j.bbamem.2016.05.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/27/2016] [Accepted: 05/17/2016] [Indexed: 10/21/2022]
Abstract
We demonstrate the use of tethered bilayer lipid membranes (tBLMs) as an experimental platform for functional and structural studies of membrane associated proteins by electrochemical techniques. The reconstitution of the cholesterol-dependent cytolysin (CDC) pyolysin (PLO) from Trueperella pyogenes into tBLMs was followed in real-time by electrochemical impedance spectroscopy (EIS). Changes of the EIS parameters of the tBLMs upon exposure to PLO solutions were consistent with the dielectric barrier damage occurring through the formation of water-filled pores in membranes. Parallel experiments involving a mutant version of PLO, which is able to bind to the membranes but does not form oligomer pores, strengthen the reliability of this methodology, since no change in the electrochemical impedance was observed. Complementary atomic force microscopy (AFM) and neutron reflectometry (NR) measurements revealed structural details of the membrane bound PLO, consistent with the structural transformations of the membrane bound toxins found for other cholesterol dependent cytolysins. In this work, using the tBLMs platform we also observed a protective effect of the dynamin inhibitor Dynasore against pyolysin as well as pneumolysin. An effect of Dynasore in tBLMs, which was earlier observed in experiments with live cells, confirms the biological relevance of the tBLMs models, as well as demonstrates the potential of the electrochemical impedance spectroscopy to quantify membrane damage by the pore forming toxins. In conclusion, tBLMs are a reliable and complementary method to explore the activity of CDCs in eukaryotic cells and to develop strategies to limit the toxic effects of CDCs.
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Affiliation(s)
- Giulio Preta
- Department of Bioelectrochemistry and Biospectroscopy, Institute of Biochemistry, Vilnius University, Vilnius, Lithuania
| | - Marija Jankunec
- Department of Bioelectrochemistry and Biospectroscopy, Institute of Biochemistry, Vilnius University, Vilnius, Lithuania
| | - Frank Heinrich
- NIST Center for Neutron Research, Gaithersburg, MD 20899, USA
| | - Sholeem Griffin
- Institute of Life Science, Swansea University Medical School, Swansea SA2 8PP, United Kingdom
| | - Iain Martin Sheldon
- Institute of Life Science, Swansea University Medical School, Swansea SA2 8PP, United Kingdom
| | - Gintaras Valincius
- Department of Bioelectrochemistry and Biospectroscopy, Institute of Biochemistry, Vilnius University, Vilnius, Lithuania.
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31
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Smith SB, Ravel J. The vaginal microbiota, host defence and reproductive physiology. J Physiol 2016; 595:451-463. [PMID: 27373840 DOI: 10.1113/jp271694] [Citation(s) in RCA: 209] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 01/28/2016] [Indexed: 02/06/2023] Open
Abstract
The interaction between the human host and the vaginal microbiota is highly dynamic. Major changes in the vaginal physiology and microbiota over a woman's lifetime are largely shaped by transitional periods such as puberty, menopause and pregnancy, while daily fluctuations in microbial composition observed through culture-independent studies are more likely to be the results of daily life activities and behaviours. The vaginal microbiota of reproductive-aged women is largely made up of at least five different community state types. Four of these community state types are dominated by lactic-acid producing Lactobacillus spp. while the fifth is commonly composed of anaerobes and strict anaerobes and is sometimes associated with vaginal symptoms. The production of lactic acid has been associated with contributing to the overall health of the vagina due to its direct and indirect effects on pathogens and host defence. Some species associated with non-Lactobacillus vaginal microbiota may trigger immune responses as well as degrade the host mucosa, processes that ultimately increase susceptibility to infections and contribute to negative reproductive outcomes such as infertility and preterm birth. Further studies are needed to better understand the functional underpinnings of how the vaginal microbiota affect host physiology but also how host physiology affects the vaginal microbiota. Understanding this fine-tuned interaction is key to maintaining women's reproductive health.
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Affiliation(s)
- Steven B Smith
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, 20742, USA
| | - Jacques Ravel
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
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Reboul CF, Whisstock JC, Dunstone MA. Giant MACPF/CDC pore forming toxins: A class of their own. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:475-86. [PMID: 26607011 DOI: 10.1016/j.bbamem.2015.11.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 01/08/2023]
Abstract
Pore Forming Toxins (PFTs) represent a key mechanism for permitting the passage of proteins and small molecules across the lipid membrane. These proteins are typically produced as soluble monomers that self-assemble into ring-like oligomeric structures on the membrane surface. Following such assembly PFTs undergo a remarkable conformational change to insert into the lipid membrane. While many different protein families have independently evolved such ability, members of the Membrane Attack Complex PerForin/Cholesterol Dependent Cytolysin (MACPF/CDC) superfamily form distinctive giant β-barrel pores comprised of up to 50 monomers and up to 300Å in diameter. In this review we focus on recent advances in understanding the structure of these giant MACPF/CDC pores as well as the underlying molecular mechanisms leading to their formation. Commonalities and evolved variations of the pore forming mechanism across the superfamily are discussed. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale.
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Affiliation(s)
- Cyril F Reboul
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, Australia
| | - James C Whisstock
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, Australia
| | - Michelle A Dunstone
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, Australia; Department of Microbiology, Monash University, Melbourne, Australia
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