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Dong M, Lu L, Xu H, Ruan Z. DC-derived CXCL10 promotes CTL activation to suppress ovarian cancer. Transl Res 2024; 272:126-139. [PMID: 38823437 DOI: 10.1016/j.trsl.2024.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 05/07/2024] [Accepted: 05/28/2024] [Indexed: 06/03/2024]
Abstract
This study investigates the role of dendritic cells (DCs), with a focus on their CXCL10 marker gene, in the activation of cytotoxic T lymphocytes (CTLs) within the ovarian cancer microenvironment and its impact on disease progression. Utilizing scRNA-seq data and immune infiltration analysis, we identified a diminished DC presence in ovarian cancer. Gene analysis pinpointed CXCL10 as a key regulator in OV progression via its influence on DCs and CTLs. Prognostic analysis and in vitro experiments substantiated this role. Our findings reveal that DC-derived CXCL10 significantly affects CTL activation and proliferation. Reduced CXCL10 levels hinder CTL cytotoxicity, promoting ovarian cancer cell migration and invasion. Experimental studies using animal models have provided further evidence that the capacity of CTLs to suppress tumor development is significantly diminished when treated with DCs that have low expression of CXCL10. Dendritic cell-derived CXCL10 emerges as a pivotal factor in restraining ovarian cancer growth and metastasis through the activation of cytotoxic T lymphocytes. This study sheds light on the crucial interplay within the ovarian cancer microenvironment, offering potential therapeutic targets for ovarian cancer treatment.
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Affiliation(s)
- Ming Dong
- Department of Obstetrics and Gynecology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, No.639, Zhi Zaoju Road, Huangpu District, Shanghai 200011, PR China
| | - Lili Lu
- Department of Obstetrics and Gynecology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, No.639, Zhi Zaoju Road, Huangpu District, Shanghai 200011, PR China
| | - Hui Xu
- Department of Obstetrics and Gynecology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, No.639, Zhi Zaoju Road, Huangpu District, Shanghai 200011, PR China
| | - Zhengyi Ruan
- Department of Obstetrics and Gynecology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, No.639, Zhi Zaoju Road, Huangpu District, Shanghai 200011, PR China.
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2
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Hajam IA, Liu GY. Linking S. aureus Immune Evasion Mechanisms to Staphylococcal Vaccine Failures. Antibiotics (Basel) 2024; 13:410. [PMID: 38786139 PMCID: PMC11117348 DOI: 10.3390/antibiotics13050410] [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: 03/18/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/25/2024] Open
Abstract
Vaccination arguably remains the only long-term strategy to limit the spread of S. aureus infections and its related antibiotic resistance. To date, however, all staphylococcal vaccines tested in clinical trials have failed. In this review, we propose that the failure of S. aureus vaccines is intricately linked to prior host exposure to S. aureus and the pathogen's capacity to evade adaptive immune defenses. We suggest that non-protective immune imprints created by previous exposure to S. aureus are preferentially recalled by SA vaccines, and IL-10 induced by S. aureus plays a unique role in shaping these non-protective anti-staphylococcal immune responses. We discuss how S. aureus modifies the host immune landscape, which thereby necessitates alternative approaches to develop successful staphylococcal vaccines.
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Affiliation(s)
- Irshad Ahmed Hajam
- Department of Pediatrics, University of California San Diego, San Diego, CA 92093, USA;
| | - George Y. Liu
- Department of Pediatrics, University of California San Diego, San Diego, CA 92093, USA;
- Division of Infectious Diseases, Rady Children’s Hospital, San Diego, CA 92123, USA
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3
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Jiang F, Wang J, Ren Z, Hu Y, Wang B, Li M, Yu J, Tang J, Guo G, Cheng Y, Han P, Shen H. Targeted Light-Induced Immunomodulatory Strategy for Implant-Associated Infections via Reversing Biofilm-Mediated Immunosuppression. ACS NANO 2024; 18:6990-7010. [PMID: 38385433 DOI: 10.1021/acsnano.3c10172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
The clinical treatment efficacy for implant-associated infections (IAIs), particularly those caused by Methicillin-resistant Staphylococcus aureus (MRSA), remains unsatisfactory, primarily due to the formation of biofilm barriers and the resulting immunosuppressive microenvironment, leading to the chronicity and recurrence of IAIs. To address this challenge, we propose a light-induced immune enhancement strategy, synthesizing BSA@MnO2@Ce6@Van (BMCV). The BMCV exhibits precise targeting and adhesion to the S. aureus biofilm-infected region, coupled with its capacity to catalyze oxygen generation from H2O2 in the hypoxic and acidic biofilm microenvironment (BME), promoting oxygen-dependent photodynamic therapy efficacy while ensuring continuous release of manganese ions. Notably, targeted BMCV can penetrate biofilms, producing ROS that degrade extracellular DNA, disrupting the biofilm structure and impairing its barrier function, making it vulnerable to infiltration and elimination by the immune system. Furthermore, light-induced reactive oxygen species (ROS) around the biofilm can lyse S. aureus, triggering bacterium-like immunogenic cell death (ICD), releasing abundant immune costimulatory factors, facilitating the recognition and maturation of antigen-presenting cells (APCs), and activating adaptive immunity. Additionally, manganese ions in the BME act as immunoadjuvants, further amplifying macrophage-mediated innate and adaptive immune responses and reversing the immunologically cold BME to an immunologically hot BME. We prove that our synthesized BMCV elicits a robust adaptive immune response in vivo, effectively clearing primary IAIs and inducing long-term immune memory to prevent recurrence. Our study introduces a potent light-induced immunomodulatory nanoplatform capable of reversing the biofilm-induced immunosuppressive microenvironment and disrupting biofilm-mediated protective barriers, offering a promising immunotherapeutic strategy for addressing challenging S. aureus IAIs.
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Affiliation(s)
- Feng Jiang
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Jian Wang
- Department of Interventional Radiology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Zun Ren
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - Yujie Hu
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Boyong Wang
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Mingzhang Li
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Jinlong Yu
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Jin Tang
- Department of Clinical Laboratory, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Geyong Guo
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Yingsheng Cheng
- Department of Interventional Radiology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
- Department of Imaging Medicine and Nuclear Medicine, Tongji Hospital, Shanghai 200065, China
| | - Pei Han
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Hao Shen
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
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4
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Kleinhenz M, Li Z, Chidella U, Picard W, Wolfe A, Popelka J, Alexander R, Montgomery CP. Toxin-neutralizing Abs are associated with improved T cell function following recovery from Staphylococcus aureus infection. JCI Insight 2024; 9:e173526. [PMID: 38236641 PMCID: PMC11143924 DOI: 10.1172/jci.insight.173526] [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: 07/11/2023] [Accepted: 01/11/2024] [Indexed: 02/23/2024] Open
Abstract
BACKGROUNDT cell responses are impaired in Staphylococcus aureus-infected children, highlighting a potential mechanism of immune evasion. This study tested the hypotheses that toxin-specific antibodies protect immune cells from bacterial killing and are associated with improved T cell function following infection.METHODSS. aureus-infected and healthy children (N = 33 each) were prospectively enrolled. During acute infection and convalescence, we quantified toxin-specific IgG levels by ELISA, antibody function using a cell killing assay, and functional T cell responses by ELISPOT.RESULTSThere were no differences in toxin-specific IgG levels or ability to neutralize toxin-mediated immune cell killing between healthy and acutely infected children, but antibody levels and function increased following infection. Similarly, T cell function, which was impaired during acute infection, improved following infection. However, the response to infection was highly variable; up to half of children did not have improved antibody or T cell function. Serum from children with higher α-hemolysin-specific IgG levels more strongly protected immune cells against toxin-mediated killing. Importantly, children whose serum more strongly protected against toxin-mediated killing also had stronger immune responses to infection, characterized by more elicited antibodies and greater improvement in T cell function following infection.CONCLUSIONThis study demonstrates that, despite T cell impairment during acute infection, S. aureus elicits toxin-neutralizing antibodies. Individual antibody responses and T cell recovery are variable. These findings also suggest that toxin-neutralizing antibodies protect antigen-presenting cells and T cells, thereby promoting immune recovery. Finally, failure to elicit toxin-neutralizing antibodies may identify children at risk for prolonged T cell suppression.FUNDINGNIH National Institute of Allergy and Infectious Diseases R01AI125489 and Nationwide Children's Hospital.
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Affiliation(s)
- Maureen Kleinhenz
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute
| | - Zhaotao Li
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute
| | - Usha Chidella
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute
| | - Walissa Picard
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute
| | | | | | - Robin Alexander
- Biostatistics Resource, Nationwide Children’s Hospital, Columbus, Ohio, USA
| | - Christopher P. Montgomery
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute
- Division of Critical Care Medicine; and
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
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Ilmain JK, Perelman SS, Panepinto MC, Irnov I, Coudray N, Samhadaneh N, Pironti A, Ueberheide B, Ekiert DC, Bhabha G, Torres VJ. Unlatching of the stem domains in the Staphylococcus aureus pore-forming leukocidin LukAB influences toxin oligomerization. J Biol Chem 2023; 299:105321. [PMID: 37802313 PMCID: PMC10665946 DOI: 10.1016/j.jbc.2023.105321] [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: 05/23/2023] [Revised: 09/22/2023] [Accepted: 09/27/2023] [Indexed: 10/08/2023] Open
Abstract
Staphylococcus aureus (S. aureus) is a serious global pathogen that causes a diverse range of invasive diseases. S. aureus utilizes a family of pore-forming toxins, known as bi-component leukocidins, to evade the host immune response and promote infection. Among these is LukAB (leukocidin A/leukocidin B), a toxin that assembles into an octameric β-barrel pore in the target cell membrane, resulting in host cell death. The established cellular receptor for LukAB is CD11b of the Mac-1 complex. Here, we show that hydrogen voltage-gated channel 1 is also required for the cytotoxicity of all major LukAB variants. We demonstrate that while each receptor is sufficient to recruit LukAB to the plasma membrane, both receptors are required for maximal lytic activity. Why LukAB requires two receptors, and how each of these receptors contributes to pore-formation remains unknown. To begin to resolve this, we performed an alanine scanning mutagenesis screen to identify mutations that allow LukAB to maintain cytotoxicity without CD11b. We discovered 30 mutations primarily localized in the stem domains of LukA and LukB that enable LukAB to exhibit full cytotoxicity in the absence of CD11b. Using crosslinking, electron microscopy, and hydroxyl radical protein footprinting, we show these mutations increase the solvent accessibility of the stem domain, priming LukAB for oligomerization. Together, our data support a model in which CD11b binding unlatches the membrane penetrating stem domains of LukAB, and this change in flexibility promotes toxin oligomerization.
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Affiliation(s)
- Juliana K Ilmain
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Sofya S Perelman
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Maria C Panepinto
- Proteomics Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, New York, USA
| | - Irnov Irnov
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Nicolas Coudray
- Applied Bioinformatics Laboratories, New York University Grossman School of Medicine, New York, New York, USA; Department of Cell Biology, New York University Grossman School of Medicine, New York, New York, USA
| | - Nora Samhadaneh
- Antimicrobial-Resistant Pathogens Program, New York University Langone Health, New York, New York, USA
| | - Alejandro Pironti
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA; Antimicrobial-Resistant Pathogens Program, New York University Langone Health, New York, New York, USA
| | - Beatrix Ueberheide
- Proteomics Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, New York, USA; Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, New York, USA; Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, New York, USA
| | - Damian C Ekiert
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA; Department of Cell Biology, New York University Grossman School of Medicine, New York, New York, USA; Antimicrobial-Resistant Pathogens Program, New York University Langone Health, New York, New York, USA
| | - Gira Bhabha
- Department of Cell Biology, New York University Grossman School of Medicine, New York, New York, USA; Antimicrobial-Resistant Pathogens Program, New York University Langone Health, New York, New York, USA
| | - Victor J Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA; Department of Host-Microbe Interactions, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
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Yang L, Li S, Chen L, Zhang Y. Emerging roles of plasmacytoid dendritic cell crosstalk in tumor immunity. Cancer Biol Med 2023; 20:j.issn.2095-3941.2023.0241. [PMID: 37817484 PMCID: PMC10618948 DOI: 10.20892/j.issn.2095-3941.2023.0241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/22/2023] [Indexed: 10/12/2023] Open
Abstract
Plasmacytoid dendritic cells (pDCs) are a pioneer cell type that produces type I interferon (IFN-I) and promotes antiviral immune responses. However, they are tolerogenic and, when recruited to the tumor microenvironment (TME), play complex roles that have long been a research focus. The interactions between pDCs and other components of the TME, whether direct or indirect, can either promote or hinder tumor development; consequently, pDCs are an intriguing target for therapeutic intervention. This review provides a comprehensive overview of pDC crosstalk in the TME, including crosstalk with various cell types, biochemical factors, and microorganisms. An in-depth understanding of pDC crosstalk in TME should facilitate the development of novel pDC-based therapeutic methods.
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Affiliation(s)
- Leilei Yang
- Biotherapy Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
- Department of Stomatology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Songya Li
- Department of Stomatology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Liuhui Chen
- Department of Stomatology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Yi Zhang
- Biotherapy Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
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7
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Chen Y, Liu Z, Lin Z, Lu M, Fu Y, Liu G, Yu B. The effect of Staphylococcus aureus on innate and adaptive immunity and potential immunotherapy for S. aureus-induced osteomyelitis. Front Immunol 2023; 14:1219895. [PMID: 37744377 PMCID: PMC10517662 DOI: 10.3389/fimmu.2023.1219895] [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: 05/09/2023] [Accepted: 08/18/2023] [Indexed: 09/26/2023] Open
Abstract
Osteomyelitis is a chronic inflammatory bone disease caused by infection of open fractures or post-operative implants. Particularly in patients with open fractures, the risk of osteomyelitis is greatly increased as the soft tissue damage and bacterial infection are often more severe. Staphylococcus aureus, one of the most common pathogens of osteomyelitis, disrupts the immune response through multiple mechanisms, such as biofilm formation, virulence factor secretion, and metabolic pattern alteration, which attenuates the effectiveness of antibiotics and surgical debridement toward osteomyelitis. In osteomyelitis, immune cells such as neutrophils, macrophages and T cells are activated in response to pathogenic bacteria invasion with excessive inflammatory factor secretion, immune checkpoint overexpression, and downregulation of immune pathway transcription factors, which enhances osteoclastogenesis and results in bone destruction. Therefore, the study of the mechanisms of abnormal immunity will be a new breakthrough in the treatment of osteomyelitis.
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Affiliation(s)
- Yingqi Chen
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Southern Medical University Nanfang Hospital, Guangzhou, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Southern Medical University Nanfang Hospital, Guangzhou, China
| | - Zixian Liu
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Southern Medical University Nanfang Hospital, Guangzhou, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Southern Medical University Nanfang Hospital, Guangzhou, China
| | - Zexin Lin
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Southern Medical University Nanfang Hospital, Guangzhou, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Southern Medical University Nanfang Hospital, Guangzhou, China
| | - Mincheng Lu
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Southern Medical University Nanfang Hospital, Guangzhou, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Southern Medical University Nanfang Hospital, Guangzhou, China
| | - Yong Fu
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Southern Medical University Nanfang Hospital, Guangzhou, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Southern Medical University Nanfang Hospital, Guangzhou, China
- Trauma Center, Department of Orthopaedic Trauma, The Second Affiliated Hospital of Hengyang Medical College, South China University, Hengyang, China
| | - Guanqiao Liu
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Southern Medical University Nanfang Hospital, Guangzhou, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Southern Medical University Nanfang Hospital, Guangzhou, China
| | - Bin Yu
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Southern Medical University Nanfang Hospital, Guangzhou, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Southern Medical University Nanfang Hospital, Guangzhou, China
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Loredan DG, Devlin JC, Lacey KA, Howard N, Chen Z, Zwack EE, Lin JD, Ruggles KV, Khanna KM, Torres VJ, Loke P. Single-Cell Analysis of CX3CR1+ Cells Reveals a Pathogenic Role for BIRC5+ Myeloid Proliferating Cells Driven by Staphylococcus aureus Leukotoxins. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:836-843. [PMID: 37466391 PMCID: PMC10450158 DOI: 10.4049/jimmunol.2300166] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 06/30/2023] [Indexed: 07/20/2023]
Abstract
Our previous studies identified a population of stem cell-like proliferating myeloid cells within inflamed tissues that could serve as a reservoir for tissue macrophages to adopt different activation states depending on the microenvironment. By lineage-tracing cells derived from CX3CR1+ precursors in mice during infection and profiling by single-cell RNA sequencing, in this study, we identify a cluster of BIRC5+ myeloid cells that expanded in the liver during chronic infection with either the parasite Schistosoma mansoni or the bacterial pathogen Staphylococcus aureus. In the absence of tissue-damaging toxins, S. aureus infection does not elicit these BIRC5+ cells. Moreover, deletion of BIRC5 from CX3CR1-expressing cells results in improved survival during S. aureus infection. Hence the combination of single-cell RNA sequencing and genetic fate-mapping CX3CR1+ cells revealed a toxin-dependent pathogenic role for BIRC5 in myeloid cells during S. aureus infection.
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Affiliation(s)
- Denis G. Loredan
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
- Vilcek Institute of Graduate Biomedical Sciences, New York University Grossman School of Medicine, New York, NY
| | - Joseph C. Devlin
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
| | - Keenan A. Lacey
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
| | - Nina Howard
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Ze Chen
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
| | - Erin E. Zwack
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
| | - Jian-Da Lin
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei City, Taiwan
- Center for Computational and Systems Biology, National Taiwan University, Taipei City, Taiwan
| | - Kelly V. Ruggles
- Institute of Systems Genetics, New York University Grossman School of Medicine, New York, NY
- Division of Precision Medicine, Department of Medicine, New York University Grossman School of Medicine, New York, NY
| | - Kamal M. Khanna
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
- Perlmutter Cancer Center, New York University Grossman School of Medicine, New York, NY
| | - Victor J. Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY
| | - P’ng Loke
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
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9
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Lu M, He R, Li C, Liu Z, Chen Y, Yang B, Zhang X, Yu B. Apolipoprotein E deficiency potentiates macrophage against Staphylococcus aureus in mice with osteomyelitis via regulating cholesterol metabolism. Front Cell Infect Microbiol 2023; 13:1187543. [PMID: 37529351 PMCID: PMC10387542 DOI: 10.3389/fcimb.2023.1187543] [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: 03/16/2023] [Accepted: 06/29/2023] [Indexed: 08/03/2023] Open
Abstract
Introduction Staphylococcus aureus (S. aureus) osteomyelitis causes a variety of metabolism disorders in microenvironment and cells. Defining the changes in cholesterol metabolism and identifying key factors involved in cholesterol metabolism disorders during S. aureus osteomyelitis is crucial to understanding the mechanisms of S. aureus osteomyelitis and is important in designing host-directed therapeutic strategies. Methods In this study, we conducted in vitro and in vivo experiments to define the effects of S. aureus osteomyelitis on cholesterol metabolism, as well as the role of Apolipoprotein E (ApoE) in regulating cholesterol metabolism by macrophages during S. aureus osteomyelitis. Results The data from GSE166522 showed that cholesterol metabolism disorder was induced by S. aureus osteomyelitis. Loss of cholesterol from macrophage obtained from mice with S. aureus osteomyelitis was detected by liquid chromatography-tandem mass spectrometry(LC-MS/MS), which is consistent with Filipin III staining results. Changes in intracellular cholesterol content influenced bactericidal capacity of macrophage. Subsequently, it was proven by gene set enrichment analysis and qPCR, that ApoE played a key role in developing cholesterol metabolism disorder in S. aureus osteomyelitis. ApoE deficiency in macrophages resulted in increased resistance to S. aureus. ApoE-deficient mice manifested abated bone destruction and decreased bacteria load. Moreover, the combination of transcriptional analysis, qPCR, and killing assay showed that ApoE deficiency led to enhanced cholesterol biosynthesis in macrophage, ameliorating anti-infection ability. Conclusion We identified a previously unrecognized role of ApoE in S. aureus osteomyelitis from the perspective of metabolic reprogramming. Hence, during treating S. aureus osteomyelitis, considering cholesterol metabolism as a potential therapeutic target presents a new research direction.
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Affiliation(s)
- Mincheng Lu
- Division of Orthopedics and Traumatology, Department of Orthopedics, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Ruiyi He
- Division of Orthopedics and Traumatology, Department of Orthopedics, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Chao Li
- Division of Orthopedics and Traumatology, Department of Orthopedics, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Zixian Liu
- Division of Orthopedics and Traumatology, Department of Orthopedics, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Yuhui Chen
- Division of Orthopedics and Traumatology, Department of Orthopedics, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Bingsheng Yang
- Division of Orthopedics and Traumatology, Department of Orthopedics, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Xianrong Zhang
- Division of Orthopedics and Traumatology, Department of Orthopedics, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Bin Yu
- Division of Orthopedics and Traumatology, Department of Orthopedics, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
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10
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Hsieh RC, Liu R, Burgin DJ, Otto M. Understanding mechanisms of virulence in MRSA: implications for antivirulence treatment strategies. Expert Rev Anti Infect Ther 2023; 21:911-928. [PMID: 37501364 DOI: 10.1080/14787210.2023.2242585] [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: 05/15/2023] [Accepted: 07/26/2023] [Indexed: 07/29/2023]
Abstract
INTRODUCTION Methicillin-resistant Staphylococcus aureus (MRSA) is a widespread pathogen, often causing recurrent and deadly infections in the hospital and community. Many S. aureus virulence factors have been suggested as potential targets for antivirulence therapy to decrease the threat of diminishing antibiotic availability. Antivirulence methods hold promise due to their adjunctive and prophylactic potential and decreased risk for selective pressure. AREAS COVERED This review describes the dominant virulence mechanisms exerted by MRSA and antivirulence therapeutics that are currently undergoing testing in clinical or preclinical stages. We also discuss the advantages and downsides of several investigational antivirulence approaches, including the targeting of bacterial transporters, host-directed therapy, and quorum-sensing inhibitors. For this review, a systematic search of literature on PubMed, Google Scholar, and Web of Science for relevant search terms was performed in April and May 2023. EXPERT OPINION Vaccine and antibody strategies have failed in clinical trials and could benefit from more basic science-informed approaches. Antivirulence-targeting approaches need to be set up better to meet the requirements of drug development, rather than only providing limited results to provide 'proof-of-principle' translational value of pathogenesis research. Nevertheless, there is great potential of such strategies and potential particular promise for novel probiotic approaches.
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Affiliation(s)
- Roger C Hsieh
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Ryan Liu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Dylan J Burgin
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
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11
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Buckley PT, Chan R, Fernandez J, Luo J, Lacey KA, DuMont AL, O'Malley A, Brezski RJ, Zheng S, Malia T, Whitaker B, Zwolak A, Payne A, Clark D, Sigg M, Lacy ER, Kornilova A, Kwok D, McCarthy S, Wu B, Morrow B, Nemeth-Seay J, Petley T, Wu S, Strohl WR, Lynch AS, Torres VJ. Multivalent human antibody-centyrin fusion protein to prevent and treat Staphylococcus aureus infections. Cell Host Microbe 2023; 31:751-765.e11. [PMID: 37098341 DOI: 10.1016/j.chom.2023.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 02/12/2023] [Accepted: 04/03/2023] [Indexed: 04/27/2023]
Abstract
Treating and preventing infections by antimicrobial-resistant bacterial pathogens is a worldwide problem. Pathogens such as Staphylococcus aureus produce an array of virulence determinants, making it difficult to identify single targets for the development of vaccines or monoclonal therapies. We described a human-derived anti-S. aureus monoclonal antibody (mAb)-centyrin fusion protein ("mAbtyrin") that simultaneously targets multiple bacterial adhesins, resists proteolysis by bacterial protease GluV8, avoids Fc engagement by S. aureus IgG-binding proteins SpA and Sbi, and neutralizes pore-forming leukocidins via fusion with anti-toxin centyrins, while maintaining Fc- and complement-mediated functions. Compared with the parental mAb, mAbtyrin protected human phagocytes and boosted phagocyte-mediated killing. The mAbtyrin also reduced pathology, reduced bacterial burden, and protected from different types of infections in preclinical animal models. Finally, mAbtyrin synergized with vancomycin, enhancing pathogen clearance in an animal model of bacteremia. Altogether, these data establish the potential of multivalent mAbs for treating and preventing S. aureus diseases.
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Affiliation(s)
- Peter T Buckley
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA.
| | - Rita Chan
- Department of Microbiology, New York University Grossman School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Jeffrey Fernandez
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Jinquan Luo
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Keenan A Lacey
- Department of Microbiology, New York University Grossman School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Ashley L DuMont
- Department of Microbiology, New York University Grossman School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Aidan O'Malley
- Department of Microbiology, New York University Grossman School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Randall J Brezski
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Songmao Zheng
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Thomas Malia
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Brian Whitaker
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Adam Zwolak
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Angela Payne
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Desmond Clark
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Martin Sigg
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Eilyn R Lacy
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Anna Kornilova
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Debra Kwok
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Steve McCarthy
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Bingyuan Wu
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Brian Morrow
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | | | - Ted Petley
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Sam Wu
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - William R Strohl
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | | | - Victor J Torres
- Department of Microbiology, New York University Grossman School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA; Antimicrobial-Resistant Pathogens Program, New York University Langone Health, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA.
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12
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Loredan DG, Devlin JC, Lacey KA, Howard N, Chen Z, Zwack EE, Lin JD, Ruggles KV, Khanna KM, Torres VJ, Loke PN. Single-cell analysis of CX3CR1 + cells reveal a pathogenic role for BIRC5 + myeloid proliferating cells driven by Staphylococcus aureus leukotoxins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.27.529760. [PMID: 36909517 PMCID: PMC10002671 DOI: 10.1101/2023.02.27.529760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Our previous studies identified a population of stem cell-like proliferating myeloid cells within inflamed tissues that could serve as a reservoir for tissue macrophages to adopt different activation states depending on the microenvironment. By lineage tracing cells derived from CX3CR1 + precursors in mice during infection and profiling by scRNA-seq, here we identify a cluster of BIRC5 + myeloid cells that expanded in the liver during either chronic infection with the parasite Schistosoma mansoni or the bacterial pathogen Staphylococcus aureus . In the absence of tissue damaging toxins, S. aureus infection does not elicit these BIRC5 + cells. Moreover, deletion of BIRC5 from CX3CR1 expressing cells results in improved survival during S. aureus infection. Hence, the combination of scRNA-Seq and genetic fate mapping CX3CR1 + cells revealed a toxin dependent pathogenic role for BIRC5 in myeloid cells during S. aureus infection.
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13
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Haag AF, Liljeroos L, Donato P, Pozzi C, Brignoli T, Bottomley MJ, Bagnoli F, Delany I. In Vivo Gene Expression Profiling of Staphylococcus aureus during Infection Informs Design of Stemless Leukocidins LukE and -D as Detoxified Vaccine Candidates. Microbiol Spectr 2023; 11:e0257422. [PMID: 36688711 PMCID: PMC9927290 DOI: 10.1128/spectrum.02574-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 01/02/2023] [Indexed: 01/24/2023] Open
Abstract
Staphylococcus aureus is a clinically important bacterial pathogen that has become resistant to treatment with most routinely used antibiotics. Alternative strategies, such as vaccination and phage therapy, are therefore actively being investigated to prevent or combat staphylococcal infections. Vaccination requires that vaccine targets are expressed at sufficient quantities during infection so that they can be targeted by the host's immune system. While our knowledge of in vitro expression levels of putative vaccine candidates is comprehensive, crucial in vivo expression data are scarce and promising vaccine candidates during in vitro assessment often prove ineffective in preventing S. aureus infection. Here, we show how a newly developed high-throughput quantitative reverse transcription-PCR (qRT-PCR) assay monitoring the expression of 84 staphylococcal genes encoding mostly virulence factors can inform the selection and design of effective vaccine candidates against staphylococcal infections. We show that this assay can accurately quantify mRNA expression levels of these genes in several host organs relying only on very limited amounts of bacterial mRNA in each sample. We selected two highly expressed genes, lukE and lukD, encoding pore-forming leukotoxins, to inform the design of detoxified recombinant proteins and showed that immunization with recombinant genetically detoxified LukED antigens conferred protection against staphylococcal skin infection in mice. Consequently, knowledge of in vivo-expressed virulence determinants can be successfully deployed to identify and select promising candidates for optimized design of effective vaccine antigens against S. aureus. Notably, this approach should be broadly applicable to numerous other pathogens. IMPORTANCE Vaccination is an attractive strategy for preventing bacterial infections in an age of increased antimicrobial resistance. However, vaccine development frequently suffers significant setbacks when candidate antigens that show promising results in in vitro experimentation fail to protect from disease. An alluring strategy is to focus resources on developing bacterial virulence factors that are expressed during disease establishment or maintenance and are critical for bacterial in-host survival as vaccine targets. While expression profiles of many virulence factors have been characterized in detail in vitro, our knowledge of their in vivo expression profiles is still scarce. Here, using a high-throughput qRT-PCR approach, we identified two highly expressed leukotoxins in a murine infection model and showed that genetically detoxified derivatives of these elicited a protective immune response in a murine skin infection model. Therefore, in vivo gene expression can inform the selection of promising candidates for the design of effective vaccine antigens.
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Affiliation(s)
- Andreas F. Haag
- GSK, Siena, Italy
- School of Medicine, University of St. Andrews, St. Andrews, United Kingdom
| | | | | | | | - Tarcisio Brignoli
- GSK, Siena, Italy
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
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14
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Francis D, Bhairaddy A, Joy A, Hari GV, Francis A. Secretory proteins in the orchestration of microbial virulence: The curious case of Staphylococcus aureus. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 133:271-350. [PMID: 36707204 DOI: 10.1016/bs.apcsb.2022.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Microbial virulence showcases an excellent model for adaptive changes that enable an organism to survive and proliferate in a hostile environment and exploit host resources to its own benefit. In Staphylococcus aureus, an opportunistic pathogen of the human host, known for the diversity of the disease conditions it inflicts and the rapid evolution of antibiotic resistance, virulence is a consequence of having a highly plastic genome that is amenable to quick reprogramming and the ability to express a diverse arsenal of virulence factors. Virulence factors that are secreted to the host milieu effectively manipulate the host conditions to favor bacterial survival and growth. They assist in colonization, nutrient acquisition, immune evasion, and systemic spread. The structural and functional characteristics of the secreted virulence proteins have been shaped to assist S. aureus in thriving and disseminating effectively within the host environment and exploiting the host resources to its best benefit. With the aim of highlighting the importance of secreted virulence proteins in bacterial virulence, the present chapter provides a comprehensive account of the role of the major secreted proteins of S. aureus in orchestrating its virulence in the human host.
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Affiliation(s)
- Dileep Francis
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India.
| | - Anusha Bhairaddy
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India
| | - Atheene Joy
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India
| | | | - Ashik Francis
- Rajiv Gandhi Centre for Biotechnology, Trivandrum, Kerala, India
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15
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Langouët-Astrié C, Oshima K, McMurtry SA, Yang Y, Kwiecinski JM, LaRivière WB, Kavanaugh JS, Zakharevich I, Hansen KC, Shi D, Zhang F, Boguslawski KM, Perelman SS, Su G, Torres VJ, Liu J, Horswill AR, Schmidt EP. The influenza-injured lung microenvironment promotes MRSA virulence, contributing to severe secondary bacterial pneumonia. Cell Rep 2022; 41:111721. [PMID: 36450248 PMCID: PMC10082619 DOI: 10.1016/j.celrep.2022.111721] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 10/12/2022] [Accepted: 11/03/2022] [Indexed: 12/03/2022] Open
Abstract
Influenza infection is substantially worsened by the onset of secondary pneumonia caused by bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). The bidirectional interaction between the influenza-injured lung microenvironment and MRSA is poorly understood. By conditioning MRSA ex vivo in bronchoalveolar lavage fluid collected from mice at various time points of influenza infection, we found that the influenza-injured lung microenvironment dynamically induces MRSA to increase cytotoxin expression while decreasing metabolic pathways. LukAB, a SaeRS two-component system-dependent cytotoxin, is particularly important to the severity of post-influenza MRSA pneumonia. LukAB's activity is likely shaped by the post-influenza lung microenvironment, as LukAB binds to (and is activated by) heparan sulfate (HS) oligosaccharide sequences shed from the epithelial glycocalyx after influenza. Our findings indicate that post-influenza MRSA pneumonia is shaped by bidirectional host-pathogen interactions: host injury triggers changes in bacterial expression of toxins, the activity of which may be shaped by host-derived HS fragments.
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Affiliation(s)
| | - Kaori Oshima
- Division of Pulmonary Sciences and Critical Care, University of Colorado Denver, Aurora, CO 80045, USA
| | - Sarah A McMurtry
- Division of Pulmonary Sciences and Critical Care, University of Colorado Denver, Aurora, CO 80045, USA
| | - Yimu Yang
- Division of Pulmonary Sciences and Critical Care, University of Colorado Denver, Aurora, CO 80045, USA
| | - Jakub M Kwiecinski
- Department of Immunology & Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow 30387, Poland
| | - Wells B LaRivière
- Division of Pulmonary Sciences and Critical Care, University of Colorado Denver, Aurora, CO 80045, USA; Medical Scientist Training Program, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Jeffrey S Kavanaugh
- Department of Immunology & Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Igor Zakharevich
- Department of Biochemistry and Molecular Genetics, University of Colorado, Aurora, CO 80045, USA
| | - Kirk C Hansen
- Department of Biochemistry and Molecular Genetics, University of Colorado, Aurora, CO 80045, USA
| | - Deling Shi
- Department of Chemistry, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Fuming Zhang
- Department of Chemistry, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Kristina M Boguslawski
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Sofya S Perelman
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Gouwei Su
- University of North Carolina Eshelman School of Pharmacy, Chapel Hill, NC 27599, USA
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Jian Liu
- University of North Carolina Eshelman School of Pharmacy, Chapel Hill, NC 27599, USA
| | - Alexander R Horswill
- Department of Immunology & Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Eric P Schmidt
- Division of Pulmonary Sciences and Critical Care, University of Colorado Denver, Aurora, CO 80045, USA; Department of Medicine, Massachusetts General Hospital, Boston, MA 02115, USA
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16
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Beesetty P, Si Y, Li Z, Yang C, Zhao F, Chong AS, Montgomery CP. Tissue specificity drives protective immunity against Staphylococcus aureus infection. Front Immunol 2022; 13:795792. [PMID: 35983063 PMCID: PMC9380724 DOI: 10.3389/fimmu.2022.795792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
Infections caused by Staphylococcus aureus range from mild to severe and frequently recur. Emerging evidence suggests that the site and severity of infection drive the potency of elicited immune responses and susceptibility to recurrent infection. In this study, we used tractable mouse models of S. aureus skin infection (SSTI) and pneumonia to determine the relative magnitude of elicited protective immunity. Surprisingly, despite both SSTI and pneumonia eliciting antibody and local effector T cell responses, only SSTI elicited protective antibody and memory T cell responses and subsequent protection against secondary SSTI and pneumonia. The failure of pneumonia to elicit protective immunity was attributed to an inability of S. aureus pneumonia to elicit toxin-specific antibodies that confer protection during secondary infection and was associated with a failure to expand antigen-specific memory T cells. Taken together, these findings emphasize the importance of understanding protective immunity in the context of the tissue-specificity.
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Affiliation(s)
- Pavani Beesetty
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH, United States
| | - Youhui Si
- Department of Surgery, the University of Chicago, Chicago, IL, United States
| | - Zhaotao Li
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH, United States
| | - Ching Yang
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH, United States
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
| | - Fan Zhao
- Department of Surgery, the University of Chicago, Chicago, IL, United States
| | - Anita S. Chong
- Department of Surgery, the University of Chicago, Chicago, IL, United States
| | - Christopher P. Montgomery
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH, United States
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, OH, United States
- Division of Critical Care Medicine, Nationwide Children’s Hospital, Columbus, OH, United States
- *Correspondence: Christopher P. Montgomery,
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17
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Exploring the Role of Staphylococcus aureus in Inflammatory Diseases. Toxins (Basel) 2022; 14:toxins14070464. [PMID: 35878202 PMCID: PMC9318596 DOI: 10.3390/toxins14070464] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 06/23/2022] [Accepted: 07/01/2022] [Indexed: 02/04/2023] Open
Abstract
Staphylococcus aureus is a very common Gram-positive bacterium, and S. aureus infections play an extremely important role in a variety of diseases. This paper describes the types of virulence factors involved, the inflammatory cells activated, the process of host cell death, and the associated diseases caused by S. aureus. S. aureus can secrete a variety of enterotoxins and other toxins to trigger inflammatory responses and activate inflammatory cells, such as keratinocytes, helper T cells, innate lymphoid cells, macrophages, dendritic cells, mast cells, neutrophils, eosinophils, and basophils. Activated inflammatory cells can express various cytokines and induce an inflammatory response. S. aureus can also induce host cell death through pyroptosis, apoptosis, necroptosis, autophagy, etc. This article discusses S. aureus and MRSA (methicillin-resistant S. aureus) in atopic dermatitis, psoriasis, pulmonary cystic fibrosis, allergic asthma, food poisoning, sarcoidosis, multiple sclerosis, and osteomyelitis. Summarizing the pathogenic mechanism of Staphylococcus aureus provides a basis for the targeted treatment of Staphylococcus aureus infection.
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18
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Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common causes of hospital-acquired pneumonia. To better manage patients with MRSA pneumonia, we require a greater understanding of the host-pathogen interactions during infection. MRSA research focuses on highly virulent and cytotoxic strains, which demonstrate robust phenotypes in animal models of infection. However, nosocomial infections are often caused by hospital-acquired MRSA (HA-MRSA) isolates that exhibit low cytotoxicity and few or no phenotypes in mice, thereby confounding mechanistic studies of pathogenesis. Consequently, virulence pathways utilized by HA-MRSA in nosocomial pneumonia are largely unknown. Here, we report that conditioning mice with broad-spectrum antibiotics lowers the barrier to pneumonia, thereby transforming otherwise avirulent HA-MRSA isolates into lethal pathogens. HA-MRSA isolates are avirulent in gnotobiotic mice, mimicking results in conventional animals. Thus, the observed enhanced susceptibility to infection in antibiotic-treated mice is not due to depletion of the microbiota. More generally, we found that antibiotic conditioning leads to increased susceptibility to infection by diverse antimicrobial-resistant (AMR) pathogens of low virulence. Treatment with antibiotics leads to dehydration and malnutrition, suggesting a potential role for these clinically relevant and reducible hospital complications in susceptibility to pathogens. In sum, the model described here mitigates the impact of low virulence in immunocompetent mice, providing a convenient model to gain fundamental insight into the pathogenesis of nosocomial pathogens.
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19
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Tsai CM, Hajam IA, Caldera JR, Liu GY. Integrating complex host-pathogen immune environments into S. aureus vaccine studies. Cell Chem Biol 2022; 29:730-740. [PMID: 35594849 DOI: 10.1016/j.chembiol.2022.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 02/16/2022] [Accepted: 04/14/2022] [Indexed: 11/18/2022]
Abstract
Staphylococcus aureus (SA) is a leading cause of bacterial infection and antibiotic resistance globally. Therefore, development of an effective vaccine has been a major goal of the SA field for the past decades. With the wealth of understanding of pathogenesis, the failure of all SA vaccine trials has been a surprise. We argue that experimental SA vaccines have not worked because vaccines have been studied in naive laboratory animals, whereas clinical vaccine efficacy is tested in immune environments reprogrammed by SA. Here, we review the failed SA vaccines that have seemingly defied all principles of vaccinology. We describe major SA evasion strategies and suggest that they reshape the immune environment in a way that makes vaccines prone to failures. We propose that appropriate integration of concepts of host-pathogen interaction into vaccine study designs could lead to insight critical for the development of an effective SA vaccine.
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Affiliation(s)
- Chih-Ming Tsai
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Irshad A Hajam
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - J R Caldera
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - George Y Liu
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA; Division of Infectious Diseases, Rady Children's Hospital, San Diego, CA 92123, USA.
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20
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Zheng X, Ma SX, St John A, Torres VJ. The Major Autolysin Atl Regulates the Virulence of Staphylococcus aureus by Controlling the Sorting of LukAB. Infect Immun 2022; 90:e0005622. [PMID: 35258336 PMCID: PMC9022505 DOI: 10.1128/iai.00056-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 01/14/2023] Open
Abstract
Infections caused by the Gram-positive bacterium Staphylococcus aureus remain a significant health threat globally. The production of bicomponent pore-forming leukocidins plays an important role in S. aureus pathogenesis. Transcriptionally, these toxins are primarily regulated by the Sae and Agr regulatory systems. However, the posttranslational regulation of these toxins is largely unexplored. In particular, one of the leukocidins, LukAB, has been shown to be both secreted into the extracellular milieu and associated with the bacterial cell envelope. Here, we report that a major cell wall hydrolase, autolysin (Atl), controls the sorting of LukAB from the cell envelope to the extracellular milieu, an effect independent of transcriptional regulation. By influencing the sorting of LukAB, Atl modulates S. aureus cytotoxicity toward primary human neutrophils. Mechanistically, we found that the reduction in peptidoglycan cleavage and increased LukAB secretion in the atl mutant can be reversed through the supplementation of exogenous mutanolysin. Altogether, our study revealed that the cell wall hydrolase activity of Atl and the cleavage of peptidoglycan play an important role in controlling the sorting of S. aureus toxins during secretion.
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Affiliation(s)
- Xuhui Zheng
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Sheya Xiao Ma
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Amelia St John
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Victor J Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, New York, USA
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21
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The Influence of Antibiotic Resistance on Innate Immune Responses to Staphylococcus aureus Infection. Antibiotics (Basel) 2022; 11:antibiotics11050542. [PMID: 35625186 PMCID: PMC9138074 DOI: 10.3390/antibiotics11050542] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/13/2022] [Accepted: 04/18/2022] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus aureus (S. aureus) causes a broad range of infections and is associated with significant morbidity and mortality. S. aureus produces a diverse range of cellular and extracellular factors responsible for its invasiveness and ability to resist immune attack. In recent years, increasing resistance to last-line anti-staphylococcal antibiotics daptomycin and vancomycin has been observed. Resistant strains of S. aureus are highly efficient in invading a variety of professional and nonprofessional phagocytes and are able to survive inside host cells. Eliciting immune protection against antibiotic-resistant S. aureus infection is a global challenge, requiring both innate and adaptive immune effector mechanisms. Dendritic cells (DC), which sit at the interface between innate and adaptive immune responses, are central to the induction of immune protection against S. aureus. However, it has been observed that S. aureus has the capacity to develop further antibiotic resistance and acquire increased resistance to immunological recognition by the innate immune system. In this article, we review the strategies utilised by S. aureus to circumvent antibiotic and innate immune responses, especially the interaction between S. aureus and DC, focusing on how this relationship is perturbed with the development of antibiotic resistance.
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22
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Wong Fok Lung T, Chan LC, Prince A, Yeaman MR, Archer NK, Aman MJ, Proctor RA. Staphylococcus aureus adaptive evolution: Recent insights on how immune evasion, immunometabolic subversion and host genetics impact vaccine development. Front Cell Infect Microbiol 2022; 12:1060810. [PMID: 36636720 PMCID: PMC9831658 DOI: 10.3389/fcimb.2022.1060810] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 11/16/2022] [Indexed: 12/28/2022] Open
Abstract
Despite meritorious attempts, a S. aureus vaccine that prevents infection or mitigates severity has not yet achieved efficacy endpoints in prospective, randomized clinical trials. This experience underscores the complexity of host-S. aureus interactions, which appear to be greater than many other bacterial pathogens against which successful vaccines have been developed. It is increasingly evident that S. aureus employs strategic countermeasures to evade or exploit human immune responses. From entering host cells to persist in stealthy intracellular reservoirs, to sensing the environmental milieu and leveraging bacterial or host metabolic products to reprogram host immune responses, S. aureus poses considerable challenges for the development of effective vaccines. The fact that this pathogen causes distinct types of infections and can undergo transient genetic, transcriptional or metabolic adaptations in vivo that do not occur in vitro compounds challenges in vaccine development. Notably, the metabolic versatility of both bacterial and host immune cells as they compete for available substrates within specific tissues inevitably impacts the variable repertoire of gene products that may or may not be vaccine antigens. In this respect, S. aureus has chameleon phenotypes that have alluded vaccine strategies thus far. Nonetheless, a number of recent studies have also revealed important new insights into pathogenesis vulnerabilities of S. aureus. A more detailed understanding of host protective immune defenses versus S. aureus adaptive immune evasion mechanisms may offer breakthroughs in the development of effective vaccines, but at present this goal remains a very high bar. Coupled with the recent advances in human genetics and epigenetics, newer vaccine technologies may enable such a goal. If so, future vaccines that protect against or mitigate the severity of S. aureus infections are likely to emerge at the intersection of precision and personalized medicine. For now, the development of S. aureus vaccines or alternative therapies that reduce mortality and morbidity must continue to be pursued.
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Affiliation(s)
| | - Liana C Chan
- Department of Medicine, David Geffen School of Medicine at University of California Loss Angeles (UCLA), Los Angeles, CA, United States.,Divisions of Molecular Medicine and Infectious Diseases, Harbor-University of California Loss Angeles (UCLA) Medical Center, Torrance, CA, United States.,Lundquist Institute for Biomedical Innovation at Harbor-University of California Loss Angeles (UCLA) Medical Center, Torrance, CA, United States
| | - Alice Prince
- Department of Pediatrics, Columbia University, New York, NY, United States
| | - Michael R Yeaman
- Department of Medicine, David Geffen School of Medicine at University of California Loss Angeles (UCLA), Los Angeles, CA, United States.,Divisions of Molecular Medicine and Infectious Diseases, Harbor-University of California Loss Angeles (UCLA) Medical Center, Torrance, CA, United States.,Lundquist Institute for Biomedical Innovation at Harbor-University of California Loss Angeles (UCLA) Medical Center, Torrance, CA, United States
| | - Nathan K Archer
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - M Javad Aman
- Integrated BioTherapeutics, Rockville, MD, United States
| | - Richard A Proctor
- Department of Medicine and Medical Microbiology/Immunology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
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23
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Thomas S, Doytchinova I. In Silico Identification of the B-Cell and T-Cell Epitopes of the Antigenic Proteins of Staphylococcus aureus for Potential Vaccines. Methods Mol Biol 2022; 2412:439-447. [PMID: 34918260 DOI: 10.1007/978-1-0716-1892-9_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Staphylococcus aureus is a leading cause of community-acquired, healthcare-associated, and hospital-acquired infections. S. aureus bacteremia is a common and serious infection with significant morbidity and mortality in older patients. The rise of antibiotic-resistant strains of S. aureus has resulted in substantial loss and effective treatment in hospitalized patients. Thus, there is a need in the development of a vaccine that would provide protection against S. aureus. The antigens of our interest include proteins that are essential for bacterial attachment and colonization (ClfA and ClfB), dermonecrosis-driven toxin (Hla), antigens that are essential for abscess formation (EsxA and EsxB), and antigens that are essential for nutrient acquisition and resistance to phagocytes killing induced by reactive oxygen species (FhuD2 and MntC). Development of a structure-based vaccine based on the antigenic protein epitopes is a novel strategy to provide protection against S. aureus. Using bioinformatic tools, we have determined the B-cell and T-cell epitopes of the antigenic proteins of S. aureus. This chapter reports identification of B-cell and T-cell epitopes of the antigenic protein that could be used in the development of effective structure-based vaccines to protect against S. aureus.
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Affiliation(s)
- Sunil Thomas
- Lankenau Institute for Medical Research, Wynnewood, PA, USA.
| | - Irini Doytchinova
- Department of Chemistry, Faculty of Pharmacy, Medical University of Sofia, Sofia, Bulgaria
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24
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韦 莉, 陈 光, 孙 潮, 张 涛, 管 俊, 金 齐. [Immune Modulatory Effect of Outer Membrane Vesicles Derived from Salmonella on Mouse Bone Marrow-Derived Dendritic Cells]. SICHUAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF SICHUAN UNIVERSITY. MEDICAL SCIENCE EDITION 2021; 52:948-953. [PMID: 34841760 PMCID: PMC10408817 DOI: 10.12182/20210860201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To study the effect of outer membrane vesicles (OMVs) derived from Salmonella typhimurium (ST) on the ultrastructural features and immune function of dendritic cells (DC). METHODS Mice bone marrow cells were collected aseptically, and myeloid DC were generated by the combined induction and amplification with recombinant mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) and recombinant mouse interleukin-4 (rm IL-4). Cell morphology was observed under inverted phase contrast microscope and the phenotype was identified with flow cytometry. ST-OMVs were isolated through ultracentrifugation. The survival rate of DC was assessed with CCK-8 assay, and the stimulus concentration of OMVs was henceforth determined. The ultrastructural characteristics of DC loaded with OMVs were observed with transmission electron microscopy. The cytokine secretion, surface molecule expression and phagocytic capacity of DC were examined with flow cytometry. RESULTS The DC induced and amplified in vitro displayed typical DC phenotype in morphological analysis and the purity of DC exceeded 85%. Transmission electron microscopy showed that there were large numbers of protrusions on the cell surface. After stimulation with ST-OMVs, it was observed that the dendritic structures on the surface of DC were reduced and a large number of phagolysosomes were found in the cytoplasm. In addition, increased numbers of mitochondria, swelling and typical apoptosis were observed. After treatment with ST-OMVs at 5 μg/mL and 10 μg/mL, the secretion of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) of DC increased significantly ( P<0.05). Furthermore, the immature DC could differentiate into mature DCs after stimulation with ST-OMVs, which were characterized by a decrease in phagocytic capacity ( P<0.05) and an upregulation of phenotypic markers ( P<0.05). CONCLUSION ST-OMVs can stimulate DC to produce TNF-α and IL-1β and promote DC maturation and antigen presentation.
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Affiliation(s)
- 莉 韦
- 蚌埠医学院 病原生物学教研室 (蚌埠 233030)Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu 233030, China
- 感染与免疫安徽省重点实验室 (蚌埠 233030)Anhui Provincial Key Laboratory of Infection and Immunity at Bengbu Medical College, Bengbu 233030, China
| | - 光璋 陈
- 蚌埠医学院 病原生物学教研室 (蚌埠 233030)Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu 233030, China
| | - 潮 孙
- 蚌埠医学院 病原生物学教研室 (蚌埠 233030)Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu 233030, China
| | - 涛 张
- 蚌埠医学院 病原生物学教研室 (蚌埠 233030)Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu 233030, China
- 感染与免疫安徽省重点实验室 (蚌埠 233030)Anhui Provincial Key Laboratory of Infection and Immunity at Bengbu Medical College, Bengbu 233030, China
| | - 俊昌 管
- 蚌埠医学院 病原生物学教研室 (蚌埠 233030)Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu 233030, China
- 感染与免疫安徽省重点实验室 (蚌埠 233030)Anhui Provincial Key Laboratory of Infection and Immunity at Bengbu Medical College, Bengbu 233030, China
| | - 齐力 金
- 蚌埠医学院 病原生物学教研室 (蚌埠 233030)Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu 233030, China
- 感染与免疫安徽省重点实验室 (蚌埠 233030)Anhui Provincial Key Laboratory of Infection and Immunity at Bengbu Medical College, Bengbu 233030, China
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25
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The cell envelope of Staphylococcus aureus selectively controls the sorting of virulence factors. Nat Commun 2021; 12:6193. [PMID: 34702812 PMCID: PMC8548510 DOI: 10.1038/s41467-021-26517-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 10/05/2021] [Indexed: 11/08/2022] Open
Abstract
Staphylococcus aureus bi-component pore-forming leukocidins are secreted toxins that directly target and lyse immune cells. Intriguingly, one of the leukocidins, Leukocidin AB (LukAB), is found associated with the bacterial cell envelope in addition to secreted into the extracellular milieu. Here, we report that retention of LukAB on the bacterial cells provides S. aureus with a pre-synthesized active toxin that kills immune cells. On the bacteria, LukAB is distributed as discrete foci in two distinct compartments: membrane-proximal and surface-exposed. Through genetic screens, we show that a membrane lipid, lysyl-phosphatidylglycerol (LPG), and lipoteichoic acid (LTA) contribute to LukAB deposition and release. Furthermore, by studying non-covalently surface-bound proteins we discovered that the sorting of additional exoproteins, such as IsaB, Hel, ScaH, and Geh, are also controlled by LPG and LTA. Collectively, our study reveals a multistep secretion system that controls exoprotein storage and protein translocation across the S. aureus cell wall.
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26
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Bline KE, Hall MW. Immune Function in Critically Ill Septic Children. Pathogens 2021; 10:1239. [PMID: 34684188 PMCID: PMC8539782 DOI: 10.3390/pathogens10101239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 09/13/2021] [Accepted: 09/22/2021] [Indexed: 11/19/2022] Open
Abstract
The inflammatory response in pediatric sepsis is highly dynamic and includes both pro- and anti-inflammatory elements that involve the innate and adaptive immune systems. While the pro-inflammatory response is responsible for the initial clinical signs and symptoms of sepsis, a concurrent compensatory anti-inflammatory response often results in an occult, but highly clinically relevant, form of acquired immunodeficiency. When severe, this is termed "immunoparalysis" and is associated with increased risks for nosocomial infection, prolonged organ dysfunction, and death. This review focuses on the pathophysiology and clinical implications of both over- and under-active immune function in septic children. Host-, disease-, and treatment-specific risk factors for immunoparalysis are reviewed along with immune phenotype-specific approaches for immunomodulation in pediatric sepsis which are currently the subject of clinical trials.
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Affiliation(s)
- Katherine Elizabeth Bline
- Division of Critical Care Medicine, Department of Pediatrics, Nationwide Children’s Hospital, Columbus, OH 43205, USA;
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27
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Raineri EJM, Altulea D, van Dijl JM. Staphylococcal trafficking and infection - from 'nose to gut' and back. FEMS Microbiol Rev 2021; 46:6321165. [PMID: 34259843 PMCID: PMC8767451 DOI: 10.1093/femsre/fuab041] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 07/11/2021] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus is an opportunistic human pathogen, which is a leading cause of infections worldwide. The challenge in treating S. aureus infection is linked to the development of multidrug-resistant strains and the mechanisms employed by this pathogen to evade the human immune defenses. In addition, S. aureus can hide asymptomatically in particular ‘protective’ niches of the human body for prolonged periods of time. In the present review, we highlight recently gained insights in the role of the human gut as an endogenous S. aureus reservoir next to the nasopharynx and oral cavity. In addition, we address the contribution of these ecological niches to staphylococcal transmission, including the roles of particular triggers as modulators of the bacterial dissemination. In this context, we present recent advances concerning the interactions between S. aureus and immune cells to understand their possible roles as vehicles of dissemination from the gut to other body sites. Lastly, we discuss the factors that contribute to the switch from colonization to infection. Altogether, we conclude that an important key to uncovering the pathogenesis of S. aureus infection lies hidden in the endogenous staphylococcal reservoirs, the trafficking of this bacterium through the human body and the subsequent immune responses.
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Affiliation(s)
- Elisa J M Raineri
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Dania Altulea
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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28
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Systemic bacterial infections affect dendritic cell development and function. Int J Med Microbiol 2021; 311:151517. [PMID: 34233227 DOI: 10.1016/j.ijmm.2021.151517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 04/29/2021] [Accepted: 06/25/2021] [Indexed: 12/24/2022] Open
Abstract
Dendritic cells (DCs) are critical in host defense against infection. DC depletion is an early event in the course of sepsis that may impair the host defense mechanisms. Here, we addressed whether DC depletion and dysfunction are pathogen-independent, mediated via pattern recognition receptors, and are due to impaired DC development upon systemic infection with the Gram-negative bacterium Escherichia coli and the Gram-positive pathogen Staphylococcus aureus. Infection with E. coli and S. aureus led to reduced numbers of splenic DC subsets and of DC progenitors in the bone marrow (BM) with this effect persisting significantly longer in mice infected with S. aureus than with E. coli. The reduction of DC subsets and their progenitors was mainly TLR-independent as was the infection-induced monopoiesis. Moreover, de novo DC development was impaired in mice infected with S. aureus, and BM cells from E. coli or S. aureus infected mice favored macrophage differentiation in vitro. As a consequence of reduced DC numbers and their reduced expression of MHC II less CD4+ and CD8+ T cells, especially Th1 and IFN-γ producing CD8+ T cells, could be detected in S. aureus compared to E. coli infected mice. These differences are reflected in the rapid killing of E. coli as opposed to an increase in bacterial load in S. aureus. In summary, our study supports the idea that systemic bacterial infections generally affect the number and development of DCs and thereby the T cell responses, but the magnitude is pathogen-dependent.
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29
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Li Z, Beesetty P, Gerges G, Kleinhenz M, Moore-Clingenpeel M, Yang C, Ahmed LB, Hensley J, Steele L, Chong AS, Montgomery CP. Impaired T lymphocyte responses during childhood Staphylococcus aureus infection. J Infect Dis 2021; 225:177-185. [PMID: 34145461 DOI: 10.1093/infdis/jiab326] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/16/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Staphylococcus aureus infections are common throughout the lifespan, with recurrent infections occuring in nearly half of infected children. There is no licensed vaccine, underscoring the need to better understand how S. aureus evades protective immunity. Despite much study, the relative contributions of antibodies and T cells to protection against S. aureus infections in humans are not fully understood. METHODS We prospectively quantified S. aureus-specific antibody levels by ELISA and T cell responses by ELISpot in S. aureus-infected and healthy children. RESULTS S. aureus-specific antibody levels and T cell responses increased with age in healthy children, suggesting a coordinated development of anti-staphylococcal immunity. Antibody levels against leukotoxin E (LukE) and Panton-Valentine leukocidin (LukS-PV), but not α-hemolysin (Hla), were higher in younger infected children, compared with healthy children; these differences disappeared in older children. We observed a striking impairment of global and S. aureus-specific T cell function in children with invasive and non-invasive infection, suggesting that S. aureus-specific immune responses are dysregulated during childhood infection regardless of the infection phenotype. CONCLUSIONS These findings identify a potential mechanism by which S. aureus infection actively evades adaptive immune responses, thereby preventing the development of protective immunty and maintaining susceptibility to recurrent infection.
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Affiliation(s)
- Zhaotao Li
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Pavani Beesetty
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - George Gerges
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Maureen Kleinhenz
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | | | - Ching Yang
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.,Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Luul B Ahmed
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Josey Hensley
- Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH, USA
| | - Lisa Steele
- Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH, USA
| | - Anita S Chong
- Department of Surgery, University of Chicago, Chicago, IL, USA
| | - Christopher P Montgomery
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.,Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, OH, USA
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30
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Perelman SS, James DBA, Boguslawski KM, Nelson CW, Ilmain JK, Zwack EE, Prescott RA, Mohamed A, Tam K, Chan R, Narechania A, Pawline MB, Vozhilla N, Moustafa AM, Kim SY, Dittmann M, Ekiert DC, Bhabha G, Shopsin B, Planet PJ, Koralov SB, Torres VJ. Genetic variation of staphylococcal LukAB toxin determines receptor tropism. Nat Microbiol 2021; 6:731-745. [PMID: 33875847 PMCID: PMC8597016 DOI: 10.1038/s41564-021-00890-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 03/11/2021] [Indexed: 02/02/2023]
Abstract
Staphylococcus aureus has evolved into diverse lineages, known as clonal complexes (CCs), which exhibit differences in the coding sequences of core virulence factors. Whether these alterations affect functionality is poorly understood. Here, we studied the highly polymorphic pore-forming toxin LukAB. We discovered that the LukAB toxin variants produced by S. aureus CC30 and CC45 kill human phagocytes regardless of whether CD11b, the previously established LukAB receptor, is present, and instead target the human hydrogen voltage-gated channel 1 (HVCN1). Biochemical studies identified the domain within human HVCN1 that drives LukAB species specificity, enabling the generation of humanized HVCN1 mice with enhanced susceptibility to CC30 LukAB and to bloodstream infection caused by CC30 S. aureus strains. Together, this work advances our understanding of an important S. aureus toxin and underscores the importance of considering genetic variation in characterizing virulence factors and understanding the tug of war between pathogens and the host.
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Affiliation(s)
- Sofya S Perelman
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - David B A James
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Kristina M Boguslawski
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Chase W Nelson
- Institute for Comparative Genomics, American Museum of Natural History, New York, NY, USA
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Juliana K Ilmain
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Erin E Zwack
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Rachel A Prescott
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Adil Mohamed
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Kayan Tam
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Rita Chan
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Apurva Narechania
- Institute for Comparative Genomics, American Museum of Natural History, New York, NY, USA
| | - Miranda B Pawline
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
- Department of Medicine, Division of Infectious Diseases, New York University Grossman School of Medicine, New York, NY, USA
| | - Nikollaq Vozhilla
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Ahmed M Moustafa
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Sang Y Kim
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
- Office of Collaborative Sciences, NYU Grossman School of Medicine, New York, NY, USA
| | - Meike Dittmann
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Damian C Ekiert
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, USA
| | - Gira Bhabha
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, USA
| | - Bo Shopsin
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
- Department of Medicine, Division of Infectious Diseases, New York University Grossman School of Medicine, New York, NY, USA
| | - Paul J Planet
- Institute for Comparative Genomics, American Museum of Natural History, New York, NY, USA
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sergei B Koralov
- Department of Pathology, 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.
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31
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Fernandez J, Sanders H, Henn J, Wilson JM, Malone D, Buoninfante A, Willms M, Chan R, DuMont AL, McLahan C, Grubb K, Romanello A, van den Dobbelsteen G, Torres VJ, Poolman JT. Vaccination with Detoxified Leukocidin AB Reduces Bacterial Load in a Staphylococcus aureus Minipig Deep Surgical Wound Infection Model. J Infect Dis 2021; 225:1460-1470. [PMID: 33895843 PMCID: PMC9016470 DOI: 10.1093/infdis/jiab219] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 04/19/2021] [Indexed: 12/15/2022] Open
Abstract
Vaccines against Staphylococcus aureus have eluded researchers for >3 decades while the burden of staphylococcal diseases has increased. Early vaccine attempts mainly used rodents to characterize preclinical efficacy, and all subsequently failed in human clinical efficacy trials. More recently, leukocidin AB (LukAB) has gained interest as a vaccine antigen. We developed a minipig deep surgical wound infection model offering 3 independent efficacy readouts: bacterial load at the superficial and at the deep-seated surgical site, and dissemination of bacteria. Due to similarities with humans, minipigs are an attractive option to study novel vaccine candidates. With this model, we characterized the efficacy of a LukAB toxoid as vaccine candidate. Compared to control animals, a 3-log reduction of bacteria at the deep-seated surgical site was observed in LukAB-treated minipigs and dissemination of bacteria was dramatically reduced. Therefore, LukAB toxoids may be a useful addition to S. aureus vaccines and warrant further study.
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Affiliation(s)
| | - H Sanders
- Janssen Vaccines & Prevention B.V., Leiden, The Netherlands
| | - J Henn
- Bacterial Vaccines, Spring House, PA, USA
| | | | - D Malone
- Bacterial Vaccines, Spring House, PA, USA
| | - A Buoninfante
- Janssen Vaccines & Prevention B.V., Leiden, The Netherlands
| | - M Willms
- Bacterial Vaccines, Spring House, PA, USA
| | - R Chan
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - A L DuMont
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - C McLahan
- In Vivo Sciences, Spring House, PA, USA
| | - K Grubb
- Bacterial Vaccines, Spring House, PA, USA
| | | | | | - V J Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - J T Poolman
- Janssen Vaccines & Prevention B.V., Leiden, The Netherlands
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32
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Tam K, Lacey KA, Devlin JC, Coffre M, Sommerfield A, Chan R, O'Malley A, Koralov SB, Loke P, Torres VJ. Targeting leukocidin-mediated immune evasion protects mice from Staphylococcus aureus bacteremia. J Exp Med 2021; 217:151907. [PMID: 32602902 PMCID: PMC7478724 DOI: 10.1084/jem.20190541] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/05/2020] [Accepted: 05/08/2020] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus is responsible for various diseases in humans, and recurrent infections are commonly observed. S. aureus produces an array of bicomponent pore-forming toxins that target and kill leukocytes, known collectively as the leukocidins. The contribution of these leukocidins to impair the development of anti–S. aureus adaptive immunity and facilitate reinfection is unclear. Using a murine model of recurrent bacteremia, we demonstrate that infection with a leukocidin mutant results in increased levels of anti–S. aureus antibodies compared with mice infected with the WT parental strain, indicating that leukocidins negatively impact the generation of anti–S. aureus antibodies in vivo. We hypothesized that neutralizing leukocidin-mediated immune subversion by vaccination may shift this host-pathogen interaction in favor of the host. Leukocidin-immunized mice produce potent leukocidin-neutralizing antibodies and robust Th1 and Th17 responses, which collectively protect against bloodstream infections. Altogether, these results demonstrate that blocking leukocidin-mediated immune evasion can promote host protection against S. aureus bloodstream infection.
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Affiliation(s)
- Kayan Tam
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
| | - Keenan A Lacey
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
| | - Joseph C Devlin
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
| | - Maryaline Coffre
- Department of Pathology, New York University Grossman School of Medicine, New York, NY
| | - Alexis Sommerfield
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
| | - Rita Chan
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
| | - Aidan O'Malley
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
| | - Sergei B Koralov
- Department of Pathology, New York University Grossman School of Medicine, New York, NY
| | - P'ng Loke
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY.,Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Victor J Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY
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Soe YM, Bedoui S, Stinear TP, Hachani A. Intracellular Staphylococcus aureus and host cell death pathways. Cell Microbiol 2021; 23:e13317. [PMID: 33550697 DOI: 10.1111/cmi.13317] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/22/2021] [Accepted: 01/23/2021] [Indexed: 12/13/2022]
Abstract
Staphylococcus aureus is a major opportunistic human pathogen that is globally prevalent. Although S. aureus and humans may have co-evolved to the point of commensalism, the bacterium is equipped with virulence factors causing devastating infections. The adoption of an intracellular lifestyle by S. aureus is an important facet of its pathogenesis. Occupying a privileged intracellular compartment permits evasion from the bactericidal actions of host immunity and antibiotics. However, this localization exposes S. aureus to cell-intrinsic processes comprising autophagy, metabolic challenges and clearance mechanisms orchestrated by host programmed cell death pathways (PCDs), including apoptosis, pyroptosis and necroptosis. Mounting evidence suggests that S. aureus deploys pathoadaptive mechanisms that modulate the expression of its virulence factors to prevent elimination through PCD pathways. In this review, we critically analyse the current literature on the interplay between S. aureus virulence factors with the key, intertwined nodes of PCD. We discuss how S. aureus adaptation to the human host plays an essential role in the evasion of PCD, and we consider future directions to study S. aureus-PCD interactions.
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Affiliation(s)
- Ye Mon Soe
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Sammy Bedoui
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Abderrahman Hachani
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
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Pore-forming toxins in infection and immunity. Biochem Soc Trans 2021; 49:455-465. [PMID: 33492383 DOI: 10.1042/bst20200836] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 01/02/2021] [Accepted: 01/06/2021] [Indexed: 12/14/2022]
Abstract
The integrity of the plasma membranes is extremely crucial for the survival and proper functioning of the cells. Organisms from all kingdoms of life employ specialized pore-forming proteins and toxins (PFPs and PFTs) that perforate cell membranes, and cause detrimental effects. PFPs/PFTs exert their damaging actions by forming oligomeric pores in the membrane lipid bilayer. PFPs/PFTs play important roles in diverse biological processes. Many pathogenic bacteria secrete PFTs for executing their virulence mechanisms. The immune system of the higher vertebrates employs PFPs to kill pathogen-infected cells and transformed cancer cells. The most obvious consequence of membrane pore-formation by the PFPs/PFTs is the killing of the target cells due to the disruption of the permeability barrier function of the plasma membranes. PFPs/PFTs can also activate diverse cellular processes that include activation of the stress-response pathways, induction of programmed cell death, and inflammation. Upon attack by the PFTs, host cells may also activate pathways to repair the injured membranes, restore cellular homeostasis, and trigger inflammatory immune responses. In this article, we present an overview of the diverse cellular responses that are triggered by the PFPs/PFTs, and their implications in the process of pathogen infection and immunity.
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Missiakas D, Winstel V. Selective Host Cell Death by Staphylococcus aureus: A Strategy for Bacterial Persistence. Front Immunol 2021; 11:621733. [PMID: 33552085 PMCID: PMC7859115 DOI: 10.3389/fimmu.2020.621733] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 12/03/2020] [Indexed: 12/12/2022] Open
Abstract
Host cell death programs are fundamental processes that shape cellular homeostasis, embryonic development, and tissue regeneration. Death signaling and downstream host cell responses are not only critical to guide mammalian development, they often act as terminal responses to invading pathogens. Here, we briefly review and contrast how invading pathogens and specifically Staphylococcus aureus manipulate apoptotic, necroptotic, and pyroptotic cell death modes to establish infection. Rather than invading host cells, S. aureus subverts these cells to produce diffusible molecules that cause death of neighboring hematopoietic cells and thus shapes an immune environment conducive to persistence. The exploitation of cell death pathways by S. aureus is yet another virulence strategy that must be juxtaposed to mechanisms of immune evasion, autophagy escape, and tolerance to intracellular killing, and brings us closer to the true portrait of this pathogen for the design of effective therapeutics and intervention strategies.
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Affiliation(s)
- Dominique Missiakas
- Howard Taylor Ricketts Laboratory, Department of Microbiology, University of Chicago, Lemont, IL, United States
| | - Volker Winstel
- Research Group Pathogenesis of Bacterial Infections, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Hannover Medical School and the Helmholtz Centre for Infection Research, Hannover, Germany
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
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36
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Ford CA, Hurford IM, Cassat JE. Antivirulence Strategies for the Treatment of Staphylococcus aureus Infections: A Mini Review. Front Microbiol 2021; 11:632706. [PMID: 33519793 PMCID: PMC7840885 DOI: 10.3389/fmicb.2020.632706] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 12/22/2020] [Indexed: 12/11/2022] Open
Abstract
Staphylococcus aureus is a Gram-positive bacterium capable of infecting nearly all host tissues, causing severe morbidity and mortality. Widespread antimicrobial resistance has emerged among S. aureus clinical isolates, which are now the most frequent causes of nosocomial infection among drug-resistant pathogens. S. aureus produces an array of virulence factors that enhance in vivo fitness by liberating nutrients from the host or evading host immune responses. Staphylococcal virulence factors have been identified as viable therapeutic targets for treatment, as they contribute to disease pathogenesis, tissue injury, and treatment failure. Antivirulence strategies, or treatments targeting virulence without direct toxicity to the inciting pathogen, show promise as an adjunctive therapy to traditional antimicrobials. This Mini Review examines recent research on S. aureus antivirulence strategies, with an emphasis on translational studies. While many different virulence factors have been investigated as therapeutic targets, this review focuses on strategies targeting three virulence categories: pore-forming toxins, immune evasion mechanisms, and the S. aureus quorum sensing system. These major areas of S. aureus antivirulence research demonstrate broad principles that may apply to other human pathogens. Finally, challenges of antivirulence research are outlined including the potential for resistance, the need to investigate multiple infection models, and the importance of studying antivirulence in conjunction with traditional antimicrobial treatments.
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Affiliation(s)
- Caleb A. Ford
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Ian M. Hurford
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN, United States
| | - James E. Cassat
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, United States
- Vanderbilt Institute for Infection, Immunology, and Inflammation (VI4), Vanderbilt University Medical Center, Nashville, TN, United States
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Vasquez MT, Lubkin A, Reyes-Robles T, Day CJ, Lacey KA, Jennings MP, Torres VJ. Identification of a domain critical for Staphylococcus aureus LukED receptor targeting and lysis of erythrocytes. J Biol Chem 2020; 295:17241-17250. [PMID: 33051210 PMCID: PMC7863875 DOI: 10.1074/jbc.ra120.015757] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 10/07/2020] [Indexed: 12/14/2022] Open
Abstract
Leukocidin ED (LukED) is a pore-forming toxin produced by Staphylococcus aureus, which lyses host cells and promotes virulence of the bacteria. LukED enables S. aureus to acquire iron by lysing erythrocytes, which depends on targeting the host receptor Duffy antigen receptor for chemokines (DARC). The toxin also targets DARC on the endothelium, contributing to the lethality observed during bloodstream infection in mice. LukED is comprised of two monomers: LukE and LukD. LukE binds to DARC and facilitates hemolysis, but the closely related Panton-Valentine leukocidin S (LukS-PV) does not bind to DARC and is not hemolytic. The interaction of LukE with DARC and the role this plays in hemolysis are incompletely characterized. To determine the domain(s) of LukE that are critical for DARC binding, we studied the hemolytic function of LukE-LukS-PV chimeras, in which areas of sequence divergence (divergence regions, or DRs) were swapped between the toxins. We found that two regions of LukE's rim domain contribute to hemolysis, namely residues 57-75 (DR1) and residues 182-196 (DR4). Interestingly, LukE DR1 is sufficient to render LukS-PV capable of DARC binding and hemolysis. Further, LukE, by binding DARC through DR1, promotes the recruitment of LukD to erythrocytes, likely by facilitating LukED oligomer formation. Finally, we show that LukE targets murine Darc through DR1 in vivo to cause host lethality. These findings expand our biochemical understanding of the LukE-DARC interaction and the role that this toxin-receptor pair plays in S. aureus pathophysiology.
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Affiliation(s)
- Marilyn T Vasquez
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Ashira Lubkin
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Tamara Reyes-Robles
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Christopher J Day
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Keenan A Lacey
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Michael P Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Victor J Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA.
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Vlaeminck J, Raafat D, Surmann K, Timbermont L, Normann N, Sellman B, van Wamel WJB, Malhotra-Kumar S. Exploring Virulence Factors and Alternative Therapies against Staphylococcus aureus Pneumonia. Toxins (Basel) 2020; 12:toxins12110721. [PMID: 33218049 PMCID: PMC7698915 DOI: 10.3390/toxins12110721] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/12/2020] [Accepted: 11/15/2020] [Indexed: 12/13/2022] Open
Abstract
Pneumonia is an acute pulmonary infection associated with high mortality and an immense financial burden on healthcare systems. Staphylococcus aureus is an opportunistic pathogen capable of inducing S. aureus pneumonia (SAP), with some lineages also showing multidrug resistance. Given the high level of antibiotic resistance, much research has been focused on targeting S. aureus virulence factors, including toxins and biofilm-associated proteins, in an attempt to develop effective SAP therapeutics. Despite several promising leads, many hurdles still remain for S. aureus vaccine research. Here, we review the state-of-the-art SAP therapeutics, highlight their pitfalls, and discuss alternative approaches of potential significance and future perspectives.
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Affiliation(s)
- Jelle Vlaeminck
- Laboratory of Medical Microbiology, Vaccine and Infectious Diseases Institute, University of Antwerp, 2610 Antwerp, Belgium; (J.V.); (L.T.)
| | - Dina Raafat
- Department of Immunology, Institute of Immunology and Transfusion Medicine, University Medicine Greifswald, 17475 Greifswald, Germany; (D.R.); (N.N.)
- Department of Microbiology and Immunology, Faculty of Pharmacy, Alexandria University, Alexandria 21521, Egypt
| | - Kristin Surmann
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany;
| | - Leen Timbermont
- Laboratory of Medical Microbiology, Vaccine and Infectious Diseases Institute, University of Antwerp, 2610 Antwerp, Belgium; (J.V.); (L.T.)
| | - Nicole Normann
- Department of Immunology, Institute of Immunology and Transfusion Medicine, University Medicine Greifswald, 17475 Greifswald, Germany; (D.R.); (N.N.)
| | - Bret Sellman
- Microbiome Discovery, Microbial Sciences, BioPharmaceuticals R & D, AstraZeneca, Gaithersburg, MD 20878, USA;
| | - Willem J. B. van Wamel
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center Rotterdam, 3015 Rotterdam, The Netherlands;
| | - Surbhi Malhotra-Kumar
- Laboratory of Medical Microbiology, Vaccine and Infectious Diseases Institute, University of Antwerp, 2610 Antwerp, Belgium; (J.V.); (L.T.)
- Correspondence: ; Tel.: +32-3-265-27-52
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39
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Lee B, Olaniyi R, Kwiecinski JM, Wardenburg JB. Staphylococcus aureus toxin suppresses antigen-specific T cell responses. J Clin Invest 2020; 130:1122-1127. [PMID: 31873074 DOI: 10.1172/jci130728] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 12/05/2019] [Indexed: 02/06/2023] Open
Abstract
Staphylococcus aureus remains a leading cause of human infection. These infections frequently recur when the skin is a primary site of infection, especially in infants and children. In contrast, invasive staphylococcal disease is less commonly associated with reinfection, suggesting that tissue-specific mechanisms govern the development of immunity. Knowledge of how S. aureus manipulates protective immunity has been hampered by a lack of antigen-specific models to interrogate the T cell response. Using a chicken egg OVA-expressing S. aureus strain to analyze OVA-specific T cell responses, we demonstrated that primary skin infection was associated with impaired development of T cell memory. Conversely, invasive infection induced antigen-specific memory and protected against reinfection. This defect in adaptive immunity following skin infection was associated with a loss of DCs, attributable to S. aureus α-toxin (Hla) expression. Gene- and immunization-based approaches to protect against Hla during skin infection restored the T cell response. Within the human population, exposure to α-toxin through skin infection may modulate the establishment of T cell-mediated immunity, adversely affecting long-term protection. These studies prompt consideration that vaccination targeting S. aureus may be most effective if delivered prior to initial contact with the organism.
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Affiliation(s)
- Brandon Lee
- Committee on Immunology, UChicago Biosciences, University of Chicago, Chicago, Illinois, USA
| | - Reuben Olaniyi
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jakub M Kwiecinski
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
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40
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FitzGerald ES, Luz NF, Jamieson AM. Competitive Cell Death Interactions in Pulmonary Infection: Host Modulation Versus Pathogen Manipulation. Front Immunol 2020; 11:814. [PMID: 32508813 PMCID: PMC7248393 DOI: 10.3389/fimmu.2020.00814] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/08/2020] [Indexed: 12/12/2022] Open
Abstract
In the context of pulmonary infection, both hosts and pathogens have evolved a multitude of mechanisms to regulate the process of host cell death. The host aims to rapidly induce an inflammatory response at the site of infection, promote pathogen clearance, quickly resolve inflammation, and return to tissue homeostasis. The appropriate modulation of cell death in respiratory epithelial cells and pulmonary immune cells is central in the execution of all these processes. Cell death can be either inflammatory or anti-inflammatory depending on regulated cell death (RCD) modality triggered and the infection context. In addition, diverse bacterial pathogens have evolved many means to manipulate host cell death to increase bacterial survival and spread. The multitude of ways that hosts and bacteria engage in a molecular tug of war to modulate cell death dynamics during infection emphasizes its relevance in host responses and pathogen virulence at the host pathogen interface. This narrative review outlines several current lines of research characterizing bacterial pathogen manipulation of host cell death pathways in the lung. We postulate that understanding these interactions and the dynamics of intracellular and extracellular bacteria RCD manipulation, may lead to novel therapeutic approaches for the treatment of intractable respiratory infections.
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Affiliation(s)
| | | | - Amanda M. Jamieson
- Division of Biology and Medicine, Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, United States
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41
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Unbiased Identification of Immunogenic Staphylococcus aureus Leukotoxin B-Cell Epitopes. Infect Immun 2020; 88:IAI.00785-19. [PMID: 32014894 DOI: 10.1128/iai.00785-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 01/26/2020] [Indexed: 12/26/2022] Open
Abstract
Unbiased identification of individual immunogenic B-cell epitopes in major antigens of a pathogen remains a technology challenge for vaccine discovery. We therefore developed a platform for rapid phage display screening of deep recombinant libraries consisting of as few as one major pathogen antigen. Using the bicomponent pore-forming leukocidin (Luk) exotoxins of the major pathogen Staphylococcus aureus as a prototype, we randomly fragmented and separately ligated the hemolysin gamma A (HlgA) and LukS genes into a custom-built phage display system, termed pComb-Opti8. Deep sequence analysis of barcoded amplimers of the HlgA and LukS gene fragment libraries demonstrated that biopannng against a cross-reactive anti-Luk monoclonal antibody (MAb) recovered convergent molecular clones with short overlapping homologous sequences. We thereby identified an 11-amino-acid sequence that is highly conserved in four Luk toxin subunits and is ubiquitous in representation within S. aureus clinical isolates. The isolated 11-amino-acid peptide probe was predicted to retain the native three-dimensional (3D) conformation seen within the Luk holotoxin. Indeed, this peptide was recognized by the selecting anti-Luk MAb, and, using mutated peptides, we showed that a particular amino acid side chain was essential for these interactions. Furthermore, murine immunization with this peptide elicited IgG responses that were highly reactive with both the autologous synthetic peptide and the full-length Luk toxin homologues. Thus, using a gene fragment- and phage display-based pipeline, we have identified and validated immunogenic B-cell epitopes that are cross-reactive between members of the pore-forming leukocidin family. This approach could be harnessed to identify novel epitopes for a much-needed S. aureus-protective subunit vaccine.
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42
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Boguslawski KM, McKeown AN, Day CJ, Lacey KA, Tam K, Vozhilla N, Kim SY, Jennings MP, Koralov SB, Elde NC, Torres VJ. Exploiting species specificity to understand the tropism of a human-specific toxin. SCIENCE ADVANCES 2020; 6:eaax7515. [PMID: 32195339 PMCID: PMC7065885 DOI: 10.1126/sciadv.aax7515] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 12/17/2019] [Indexed: 06/10/2023]
Abstract
Many pathogens produce virulence factors that are specific toward their natural host. Clinically relevant methicillin-resistant Staphylococcus aureus (MRSA) isolates are highly adapted to humans and produce an array of human-specific virulence factors. One such factor is LukAB, a recently identified pore-forming toxin that targets human phagocytes by binding to the integrin component CD11b. LukAB exhibits strong tropism toward human, but not murine, CD11b. Here, phylogenetics and biochemical studies lead to the identification of an 11-residue domain required for the specificity of LukAB toward human CD11b, which is sufficient to render murine CD11b compatible with toxin binding. CRISPR-mediated gene editing was used to replace this domain, resulting in a "humanized" mouse. In vivo studies revealed that the humanized mice exhibit enhanced susceptibility to MRSA bloodstream infection, a phenotype mediated by LukAB. Thus, these studies establish LukAB as an important toxin for MRSA bacteremia and describe a new mouse model to study MRSA pathobiology.
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Affiliation(s)
- K. M. Boguslawski
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - A. N. McKeown
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - C. J. Day
- Institute for Glycomics, Griffith University, Gold Coast, QLD 4222, Australia
| | - K. A. Lacey
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - K. Tam
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - N. Vozhilla
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - S. Y. Kim
- Office of Collaborative Sciences, New York University School of Medicine, New York, NY 10016, USA
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - M. P. Jennings
- Institute for Glycomics, Griffith University, Gold Coast, QLD 4222, Australia
| | - S. B. Koralov
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - N. C. Elde
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - V. J. Torres
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
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Molecular mechanism of leukocidin GH-integrin CD11b/CD18 recognition and species specificity. Proc Natl Acad Sci U S A 2019; 117:317-327. [PMID: 31852826 PMCID: PMC6955338 DOI: 10.1073/pnas.1913690116] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus is one of the most virulent bacterial pathogens and, in particular, has the richest repertoire of cytotoxins: A single bacterium can secrete 6 different β-barrel pore-forming toxins, with different cell type and species specificities. Each toxin engages specific receptors on target cells, but the role the receptor plays in the pore-formation process is poorly understood. Here, we determine the crystal structures of a very potent S. aureus leukocidin (LukGH) in complex with its receptor (CD11b) from a sensitive (human) and an insensitive (murine) host, and track the receptor involvement in different steps on the pore-formation pathway. These results advance the knowledge of receptor-mediated leukocidin pore formation and open ways for antileukocidin and anti-S. aureus approaches. Host–pathogen interactions are central to understanding microbial pathogenesis. The staphylococcal pore-forming cytotoxins hijack important immune molecules but little is known about the underlying molecular mechanisms of cytotoxin–receptor interaction and host specificity. Here we report the structures of a staphylococcal pore-forming cytotoxin, leukocidin GH (LukGH), in complex with its receptor (the α-I domain of complement receptor 3, CD11b-I), both for the human and murine homologs. We observe 2 binding interfaces, on the LukG and the LukH protomers, and show that human CD11b-I induces LukGH oligomerization in solution. LukGH binds murine CD11b-I weakly and is inactive toward murine neutrophils. Using a LukGH variant engineered to bind mouse CD11b-I, we demonstrate that cytolytic activity does not only require binding but also receptor-dependent oligomerization. Our studies provide an unprecedented insight into bicomponent leukocidin–host receptor interaction, enabling the development of antitoxin approaches and improved animal models to explore these approaches.
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44
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de Souza Feitosa Lima IM, Zagmignan A, Santos DM, Maia HS, Dos Santos Silva L, da Silva Cutrim B, Vieira SL, Bezerra Filho CM, de Sousa EM, Napoleão TH, Krogfelt KA, Løbner-Olesen A, Paiva PMG, Nascimento da Silva LC. Schinus terebinthifolia leaf lectin (SteLL) has anti-infective action and modulates the response of Staphylococcus aureus-infected macrophages. Sci Rep 2019; 9:18159. [PMID: 31796807 PMCID: PMC6890730 DOI: 10.1038/s41598-019-54616-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 11/18/2019] [Indexed: 02/07/2023] Open
Abstract
Staphylococcus aureus is recognized as an important pathogen causing a wide spectrum of diseases. Here we examined the antimicrobial effects of the lectin isolated from leaves of Schinus terebinthifolia Raddi (SteLL) against S. aureus using in vitro assays and an infection model based on Galleria mellonella larvae. The actions of SteLL on mice macrophages and S. aureus-infected macrophages were also evaluated. SteLL at 16 µg/mL (8 × MIC) increased cell mass and DNA content of S. aureus in relation to untreated bacteria, suggesting that SteLL impairs cell division. Unlike ciprofloxacin, SteLL did not induce the expression of recA, crucial for DNA repair through SOS response. The antimicrobial action of SteLL was partially inhibited by 50 mM N-acetylglucosamine. SteLL reduced staphyloxathin production and increased ciprofloxacin activity towards S. aureus. This lectin also improved the survival of G. mellonella larvae infected with S. aureus. Furthermore, SteLL induced the release of cytokines (IL-6, IL-10, IL-17A, and TNF-α), nitric oxide and superoxide anion by macrophagens. The lectin improved the bactericidal action of macrophages towards S. aureus; while the expression of IL-17A and IFN-γ was downregulated in infected macrophages. These evidences suggest SteLL as important lead molecule in the development of anti-infective agents against S. aureus.
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Affiliation(s)
| | - Adrielle Zagmignan
- Programas de Pós-Graduação, Universidade Ceuma, São Luís, Maranhão, Brazil
| | | | | | | | | | | | | | | | | | - Karen Angeliki Krogfelt
- Department of Viral and Microbial Diagnostics, Statens Serum Institut, Copenhagen, Denmark
- Department of Science and Environment, Roskilde University, 4000, Roskilde, Denmark
| | - Anders Løbner-Olesen
- Department of Biology, Section for Functional Genomics, University of Copenhagen, Copenhagen, Denmark
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45
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Rational Design of Toxoid Vaccine Candidates for Staphylococcus aureus Leukocidin AB (LukAB). Toxins (Basel) 2019; 11:toxins11060339. [PMID: 31207937 PMCID: PMC6628420 DOI: 10.3390/toxins11060339] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus aureus (SA) infections cause high mortality and morbidity in humans. Being central to its pathogenesis, S. aureus thwarts the host defense by secreting a myriad of virulence factors, including bicomponent, pore-forming leukotoxins. While all vaccine development efforts that aimed at achieving opsonophagocytic killing have failed, targeting virulence by toxoid vaccines represents a novel approach to preventing mortality and morbidity that are caused by SA. The recently discovered leukotoxin LukAB kills human phagocytes and monocytes and it is present in all known S. aureus clinical isolates. While using a structure-guided approach, we generated a library of mutations that targeted functional domains within the LukAB heterodimer to identify attenuated toxoids as potential vaccine candidates. The mutants were evaluated based on expression, solubility, yield, biophysical properties, cytotoxicity, and immunogenicity, and several fully attenuated LukAB toxoids that were capable of eliciting high neutralizing antibody titers were identified. Rabbit polyclonal antibodies against the lead toxoid candidate provided potent neutralization of LukAB. While the neutralization of LukAB alone was not sufficient to fully suppress leukotoxicity in supernatants of S. aureus USA300 isolates, a combination of antibodies against LukAB, α-toxin, and Panton-Valentine leukocidin completely neutralized the cytotoxicity of these strains. These data strongly support the inclusion of LukAB toxoids in a multivalent toxoid vaccine for the prevention of S. aureus disease.
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Abstract
Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide. Despite broad literature including basic and translational scientific studies, many gaps in our understanding of host-pathogen interactions remain. In this review, pathogen virulence factors that drive lung infection and injury are discussed in relation to their associated host immune pathways. CAP epidemiology is considered, with a focus on Staphylococcus aureus and Streptococcus pneumoniae as primary pathogens. Bacterial factors involved in nasal colonization and subsequent virulence are illuminated. A particular emphasis is placed on bacterial pore-forming toxins, host cell death, and inflammasome activation. Identified host-pathogen interactions are then examined by linking pathogen factors to aberrant host response pathways in the context of acute lung injury in both primary and secondary infection. While much is known regarding bacterial virulence and host immune responses, CAP management is still limited to mostly supportive care. It is likely that improvements in therapy will be derived from combinatorial targeting of both pathogen virulence factors and host immunomodulation.
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Richardson JR, Armbruster NS, Günter M, Biljecki M, Klenk J, Heumos S, Autenrieth SE. PSM Peptides From Community-Associated Methicillin-Resistant Staphylococcus aureus Impair the Adaptive Immune Response via Modulation of Dendritic Cell Subsets in vivo. Front Immunol 2019; 10:995. [PMID: 31134074 PMCID: PMC6524657 DOI: 10.3389/fimmu.2019.00995] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 04/17/2019] [Indexed: 12/16/2022] Open
Abstract
Dendritic cells (DCs) are key players of the immune system and thus a target for immune evasion by pathogens. We recently showed that the virulence factors phenol-soluble-modulins (PSMs) produced by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains induce tolerogenic DCs upon Toll-like receptor activation via the p38-CREB-IL-10 pathway in vitro. Here, we addressed the hypothesis that S. aureus PSMs disturb the adaptive immune response via modulation of DC subsets in vivo. Using a systemic mouse infection model we found that S. aureus reduced the numbers of splenic DC subsets, mainly CD4+ and CD8+ DCs independently of PSM secretion. S. aureus infection induced upregulation of the C-C motif chemokine receptor 7 (CCR7) on the surface of all DC subsets, on CD4+ DCs in a PSM-dependent manner, together with increased expression of MHCII, CD86, CD80, CD40, and the co-inhibitory molecule PD-L2, with only minor effects of PSMs. Moreover, PSMs increased IL-10 production in the spleen and impaired TNF production by CD4+ DCs. Besides, S. aureus PSMs reduced the number of CD4+ T cells in the spleen, whereas CD4+CD25+Foxp3+ regulatory T cells (Tregs) were increased. In contrast, Th1 and Th17 priming and IFN-γ production by CD8+ T cells were impaired by S. aureus PSMs. Thus, PSMs from highly virulent S. aureus strains modulate the adaptive immune response in the direction of tolerance by affecting DC functions.
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Affiliation(s)
| | - Nicole S Armbruster
- Department of Internal Medicine II, University of Tübingen, Tübingen, Germany
| | - Manina Günter
- Department of Internal Medicine II, University of Tübingen, Tübingen, Germany
| | - Michelle Biljecki
- Department of Internal Medicine II, University of Tübingen, Tübingen, Germany
| | - Juliane Klenk
- Department of Internal Medicine II, University of Tübingen, Tübingen, Germany
| | - Simon Heumos
- Quantitative Biology Center, University of Tübingen, Tübingen, Germany
| | - Stella E Autenrieth
- Department of Internal Medicine II, University of Tübingen, Tübingen, Germany
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