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Liu A, Garrett S, Hong W, Zhang J. Staphylococcus aureus Infections and Human Intestinal Microbiota. Pathogens 2024; 13:276. [PMID: 38668232 PMCID: PMC11053856 DOI: 10.3390/pathogens13040276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 03/18/2024] [Accepted: 03/23/2024] [Indexed: 04/29/2024] Open
Abstract
Staphylococcus aureus (S. aureus) is a common pathogen that can cause many human diseases, such as skin infection, food poisoning, endocarditis, and sepsis. These diseases can be minor infections or life-threatening, requiring complex medical management resulting in substantial healthcare costs. Meanwhile, as the critically ignored "organ," the intestinal microbiome greatly impacts physiological health, not only in gastrointestinal diseases but also in disorders beyond the gut. However, the correlation between S. aureus infection and intestinal microbial homeostasis is largely unknown. Here, we summarized the recent progress in understanding S. aureus infections and their interactions with the microbiome in the intestine. These summarizations will help us understand the mechanisms behind these infections and crosstalk and the challenges we are facing now, which could contribute to preventing S. aureus infections, effective treatment investigation, and vaccine development.
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Affiliation(s)
- Aotong Liu
- Department of Pharmacology & Regenerative Medicine, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA;
| | - Shari Garrett
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA;
- Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Wanqing Hong
- Faculty of Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
- School of Chemistry & Chemical Engineering and Materials Sciences, Shandong Normal University, Jinan 250061, China
| | - Jilei Zhang
- Department of Pharmacology & Regenerative Medicine, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA;
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Ming K, Xing B, Hu Y, Mei M, Huang W, Hu X, Wei Z. De novo design of a protein binder against Staphylococcus enterotoxin B. Int J Biol Macromol 2024; 257:128666. [PMID: 38070805 DOI: 10.1016/j.ijbiomac.2023.128666] [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: 10/09/2023] [Revised: 12/03/2023] [Accepted: 12/06/2023] [Indexed: 01/26/2024]
Abstract
Staphylococcus enterotoxin B (SEB) interacts with MHC-II molecules to overactivate immune cells and thereby to produce excessive pro-inflammatory cytokines. Disrupting the interactions between SEB and MHC-II helps eliminate the lethal threat posed by SEB. In this study, a de novo computational approach was used to design protein binders targeting SEB. The MHC-II binding domain of SEB was selected as the target, and the possible promising binding mode was broadly explored. The obtained original binder was folded into triple-helix bundles and contained 56 amino acids with molecular weight 5.9 kDa. The interface of SEB and the binder was highly hydrophobic. ProteinMPNN optimization further enlarged the hydrophobic region of the binder and improved the stability of the binder-SEB complex. In vitro study demonstrated that the optimized binder significantly inhibited the inflammatory response induced by SEB. Overall, our research demonstrated the applicability of this approach in de novo designing protein binders against SEB, and thereby providing potential therapeutics for SEB induced diseases.
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Affiliation(s)
- Ke Ming
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China; Hubei Jiangxia Laboratory, Wuhan, Hubei, PR China
| | - Banbin Xing
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Yang Hu
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Meng Mei
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Wenli Huang
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Xiaoyu Hu
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Zigong Wei
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China; Hubei Jiangxia Laboratory, Wuhan, Hubei, PR China; Hubei Province Key Laboratory of Biotechnology of Chinese Traditional Medicine, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of life sciences, Hubei University, Wuhan, Hubei, PR China.
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Ming K, Hu Y, Zhu M, Xing B, Mei M, Wei Z. Development of nanobodies against Staphylococcus enterotoxin B through yeast surface display. Int J Biol Macromol 2023; 253:126822. [PMID: 37703983 DOI: 10.1016/j.ijbiomac.2023.126822] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/15/2023]
Abstract
Staphylococcus enterotoxin B (SEB) is one of the primary virulence factors of Staphylococcus aureus but there is still a lack of targeted drugs. SEB activates immune cells via interacting with MHC-II on antigen-presenting cells, leading to the production of large amounts of pro-inflammatory cytokines. Blocking the interaction between SEB and MHC-II can avert the overactivation of immune cells. Nanobodies are the smallest functional antibodies that can bind stably to antigens. In this study, an ideal approach to obtain specific nanobodies without immunizing camelids was introduced. We constructed a library containing up to 5 × 108 nanobodies, and then screened those targeting SEB by using yeast surface display (YSD) technique and fluorescence-activated cell sorting (FACS). A total of 8 nanobodies with divergent complementarity-determining regions (CDRs) sequences were identified and one candidate Nb8 with high affinity to SEB was isolated. In vitro study demonstrated that Nb8 significantly inhibited SEB-induced inflammatory response. Molecular docking simulation indicated that the unique CDR3 sequence contributed to the binding of Nb8 to the MHC-II binding domain of SEB and accordingly cut off the connection between SEB and MHC-II. Our efforts contributed to the development of specific nanobodies for eliminating the threats of SEB.
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Affiliation(s)
- Ke Ming
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Yang Hu
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Meijun Zhu
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Banbin Xing
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Meng Mei
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China
| | - Zigong Wei
- School of life sciences, Hubei University, Wuhan, Hubei, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China; National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of life sciences, Hubei University, Wuhan, Hubei, PR China.
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Hughes AC, Kirkland M, Du W, Rasooly R, Hernlem B, Tam C, Zhang Y, He X. Development of Thermally Stable Nanobodies for Detection and Neutralization of Staphylococcal Enterotoxin B. Toxins (Basel) 2023; 15:400. [PMID: 37368700 DOI: 10.3390/toxins15060400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/02/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
In this study, sixteen unique staphylococcal enterotoxin B (SEB)-reactive nanobodies (nbs), including ten monovalent and six bivalent nbs, were developed. All characterized nbs were highly specific for SEB and did not cross-react with other staphylococcal enterotoxins (SE). Several formats of highly sensitive enzyme-linked immunosorbent assays (ELISAs) were established using SEB nbs and a polyclonal antibody (pAb). The lowest limit of detection (LOD) reached 50 pg/mL in PBS. When applied to an ELISA to detect SEB-spiked milk (a commonly contaminated foodstuff), a LOD as low as 190 pg/mL was obtained. The sensitivity of ELISA was found to increase concurrently with the valency of nbs used in the assay. In addition, a wide range of thermal tolerance was observed among the sixteen nbs, with a subset of nbs, SEB-5, SEB-9, and SEB-62, retaining activity even after exposure to 95 °C for 10 min, whereas the conventional monoclonal and polyclonal antibodies exhibited heat-labile properties. Several nbs demonstrated a long shelf-life, with one nb (SEB-9) retaining 93% of its activity after two weeks of storage at room temperature. In addition to their usage in toxin detection, eleven out of fifteen nbs were capable of neutralizing SEB's super-antigenic activity, demonstrated by their inhibition on IL-2 expression in an ex vivo human PBMC assay. Compared to monoclonal and polyclonal antibodies, the nbs are relatively small, thermally stable, and easy to produce, making them useful in applications for sensitive, specific, and cost-effective detection and management of SEB contamination in food products.
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Affiliation(s)
- Anna C Hughes
- Western Regional Research Center United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA
| | - Marina Kirkland
- Western Regional Research Center United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA
| | - Wenxian Du
- Western Regional Research Center United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA
| | - Reuven Rasooly
- Western Regional Research Center United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA
| | - Bradley Hernlem
- Western Regional Research Center United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA
| | - Christina Tam
- Western Regional Research Center United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA
| | - Yuzhu Zhang
- Western Regional Research Center United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA
| | - Xiaohua He
- Western Regional Research Center United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA
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SARS-CoV-2 Spike Does Not Possess Intrinsic Superantigen-like Inflammatory Activity. Cells 2022; 11:cells11162526. [PMID: 36010602 PMCID: PMC9406418 DOI: 10.3390/cells11162526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 08/12/2022] [Indexed: 11/24/2022] Open
Abstract
Multisystem inflammatory syndrome in children (MIS-C) is a rare hyperinflammatory disease occurring several weeks after SARS-CoV-2 infection. The clinical similarities between MIS-C and the toxic shock syndrome, together with the preferential expansion of T cells with a T-cell receptor variable β chain (TCRVβ) skewing, suggested a superantigen theory of MIS-C. For instance, recent in silico modelling evidenced the presence of a highly conserved motif within SARS-CoV-2 spike protein similar in structure to the superantigenic fragment of staphylococcal enterotoxin B (SEB). However, experimental data on the superantigenic activity of the SARS-CoV-2 spike have not yet been provided. Here, we assessed the superantigenic activity of the SARS-CoV-2 spike by analysing inflammatory cytokine production in both Jurkat cells and the peripheral blood CD4+ T cells stimulated with the SARS-CoV-2 spike or SEB as a control. We found that, unlike SEB, the SARS-CoV-2 spike does not exhibit an intrinsic superantigen-like activity.
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Kunkl M, Amormino C, Caristi S, Tedeschi V, Fiorillo MT, Levy R, Popugailo A, Kaempfer R, Tuosto L. Binding of Staphylococcal Enterotoxin B (SEB) to B7 Receptors Triggers TCR- and CD28-Mediated Inflammatory Signals in the Absence of MHC Class II Molecules. Front Immunol 2021; 12:723689. [PMID: 34489975 PMCID: PMC8418141 DOI: 10.3389/fimmu.2021.723689] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 08/02/2021] [Indexed: 01/19/2023] Open
Abstract
The inflammatory activity of staphylococcal enterotoxin B (SEB) relies on its capacity to trigger polyclonal T-cell activation by binding both T-cell receptor (TCR) and costimulatory receptor CD28 on T cells and MHC class II and B7 molecules on antigen presenting cells (APC). Previous studies highlighted that SEB may bind TCR and CD28 molecules independently of MHC class II, yet the relative contribution of these interactions to the pro-inflammatory function of SEB remained unclear. Here, we show that binding to MHC class II is dispensable for the inflammatory activity of SEB, whereas binding to TCR, CD28 and B7 molecules is pivotal, in both human primary T cells and Jurkat T cell lines. In particular, our finding is that binding of SEB to B7 molecules suffices to trigger both TCR- and CD28-mediated inflammatory signalling. We also provide evidence that, by strengthening the interaction between CD28 and B7, SEB favours the recruitment of the TCR into the immunological synapse, thus inducing lethal inflammatory signalling.
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Affiliation(s)
- Martina Kunkl
- Department of Biology and Biotechnology Charles Darwin, Sapienza University, Rome, Italy.,Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University, Rome, Italy
| | - Carola Amormino
- Department of Biology and Biotechnology Charles Darwin, Sapienza University, Rome, Italy.,Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University, Rome, Italy
| | - Silvana Caristi
- Department of Biology and Biotechnology Charles Darwin, Sapienza University, Rome, Italy.,Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University, Rome, Italy
| | - Valentina Tedeschi
- Department of Biology and Biotechnology Charles Darwin, Sapienza University, Rome, Italy
| | - Maria Teresa Fiorillo
- Department of Biology and Biotechnology Charles Darwin, Sapienza University, Rome, Italy
| | - Revital Levy
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Andrey Popugailo
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Raymond Kaempfer
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Loretta Tuosto
- Department of Biology and Biotechnology Charles Darwin, Sapienza University, Rome, Italy.,Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University, Rome, Italy
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Bacteria and Host Interplay in Staphylococcus aureus Septic Arthritis and Sepsis. Pathogens 2021; 10:pathogens10020158. [PMID: 33546401 PMCID: PMC7913561 DOI: 10.3390/pathogens10020158] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/28/2021] [Accepted: 01/30/2021] [Indexed: 12/22/2022] Open
Abstract
Staphylococcus aureus (S. aureus) infections are a major healthcare challenge and new treatment alternatives are needed. S. aureus septic arthritis, a debilitating joint disease, causes permanent joint dysfunction in almost 50% of the patients. S. aureus bacteremia is associated with higher mortalities than bacteremia caused by most other microbes and can develop to severe sepsis and death. The key to new therapies is understanding the interplay between bacterial virulence factors and host immune response, which decides the disease outcome. S. aureus produces numerous virulence factors that facilitate bacterial dissemination, invasion into joint cavity, and cause septic arthritis. Monocytes, activated by several components of S. aureus such as lipoproteins, are responsible for bone destructions. In S. aureus sepsis, cytokine storm induced by S. aureus components leads to the hyperinflammatory status, DIC, multiple organ failure, and later death. The immune suppressive therapies at the very early time point might be protective. However, the timing of treatment is crucial, as late treatment may aggravate the immune paralysis and lead to uncontrolled infection and death.
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Lakshmi SA, Bhaskar JP, Krishnan V, Sethupathy S, Pandipriya S, Aruni W, Pandian SK. Inhibition of biofilm and biofilm-associated virulence factor production in methicillin-resistant Staphylococcus aureus by docosanol. J Biotechnol 2020; 317:59-69. [PMID: 32353392 DOI: 10.1016/j.jbiotec.2020.04.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/25/2020] [Accepted: 04/23/2020] [Indexed: 12/14/2022]
Abstract
Antimicrobial resistance is a major public health concern in infection control. Hence, a multi-pronged approach is necessary to curb the severity of infections. The present study entails the identification of docosanol (fatty alcohol) from Streptomyces as a novel antibiofilm agent which can target the virulence factors of MRSA. Results showed that docosanol as a potent antibiofilm agent and found to inhibit several virulence factors of MRSA. The antibiofilm efficacy of docosanol analyzed through light and scanning electron microscopy showed a significant reduction in adherent cells. Moreover, analysis of three-dimensional structure of biofilm matrix by confocal laser scanning microscope demonstrated effective antibiofilm potential of docosanol. In addition, docosanol reduced the survival rate of MRSA in healthy human blood and enhanced the neutrophil-mediated killing by interfering with hemolysin production. RT-qPCR analysis revealed the down regulation of several virulence genes, possibly by affecting the expression of the accessory gene regulator (agr) system and transcriptional regulator sarA. These findings suggest that docosanol could effectively reduce the biofilm phenotype and virulence production, and thus becomes a promising candidate to treat MRSA infections.
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Affiliation(s)
- Selvaraj Alagu Lakshmi
- Department of Biotechnology, Alagappa University, Science Campus, Karaikudi, Tamil Nadu, India
| | | | | | - Sivasamy Sethupathy
- Department of Biotechnology, Alagappa University, Science Campus, Karaikudi, Tamil Nadu, India
| | - Selvapandi Pandipriya
- Department of Biotechnology, Alagappa University, Science Campus, Karaikudi, Tamil Nadu, India
| | - Wilson Aruni
- Sathyabama Institute of Science and Technology, Chennai, Tamil Nadu, India; Musculoskeletal Disease Research Center, US Department of Veteran Affairs, VA, California, USA
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Popugailo A, Rotfogel Z, Supper E, Hillman D, Kaempfer R. Staphylococcal and Streptococcal Superantigens Trigger B7/CD28 Costimulatory Receptor Engagement to Hyperinduce Inflammatory Cytokines. Front Immunol 2019; 10:942. [PMID: 31114583 PMCID: PMC6503043 DOI: 10.3389/fimmu.2019.00942] [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] [Received: 12/27/2018] [Accepted: 04/12/2019] [Indexed: 11/13/2022] Open
Abstract
Staphylococcal and streptococcal superantigens are virulence factors that cause toxic shock by hyperinducing inflammatory cytokines. Effective T-cell activation requires interaction between the principal costimulatory receptor CD28 and its two coligands, B7-1 (CD80) and B7-2 (CD86). To elicit an inflammatory cytokine storm, bacterial superantigens must bind directly into the homodimer interfaces of CD28 and B7-2. Recent evidence revealed that by engaging CD28 and B7-2 directly at their dimer interface, staphylococcal enterotoxin B (SEB) potently enhances intercellular synapse formation mediated by B7-2 and CD28, resulting in T-cell hyperactivation. Here, we addressed the question, whether diverse bacterial superantigens share the property of triggering B7-2/CD28 receptor engagement and if so, whether they are capable of enhancing also the interaction between B7-1 and CD28, which occurs with an order-of-magnitude higher affinity. To this end, we compared the ability of distinct staphylococcal and streptococcal superantigens to enhance intercellular B7-2/CD28 engagement. Each of these diverse superantigens promoted B7-2/CD28 engagement to a comparable extent. Moreover, they were capable of triggering the intercellular B7-1/CD28 interaction, analyzed by flow cytometry of co-cultured cell populations transfected separately to express human CD28 or B7-1. Streptococcal mitogenic exotoxin Z (SMEZ), the most potent superantigen known, was as sensitive as SEB, SEA and toxic shock syndrome toxin-1 (TSST-1) to inhibition of inflammatory cytokine induction by CD28 and B7-2 dimer interface mimetic peptides. Thus, superantigens act not only by mediating unconventional interaction between MHC-II molecule and T-cell receptor but especially, by strongly promoting engagement of CD28 by its B7-2 and B7-1 coligands, a critical immune checkpoint, forcing the principal costimulatory axis to signal excessively. Our results show that the diverse superantigens use a common mechanism to subvert the inflammatory response, strongly enhancing B7-1/CD28 and B7-2/CD28 costimulatory receptor engagement.
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Affiliation(s)
- Andrey Popugailo
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ziv Rotfogel
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Emmanuelle Supper
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Dalia Hillman
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Raymond Kaempfer
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
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Miranda D, Bulger EM. Novel Immune Therapies in the Management of Streptococcal Sepsis and Necrotizing Soft Tissue Infections. Surg Infect (Larchmt) 2018; 19:745-749. [DOI: 10.1089/sur.2018.225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- David Miranda
- Department of Surgery, University of Washington, Harborview Medical Center, Seattle, Washington
| | - Eileen M. Bulger
- Department of Surgery, University of Washington, Harborview Medical Center, Seattle, Washington
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12
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Bacterial Superantigen Toxins, CD28, and Drug Development. Toxins (Basel) 2018; 10:toxins10110459. [PMID: 30404186 PMCID: PMC6265702 DOI: 10.3390/toxins10110459] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 11/02/2018] [Accepted: 11/04/2018] [Indexed: 01/26/2023] Open
Abstract
During severe bacterial infections, death and disease are often caused by an overly strong immune response of the human host. Acute toxic shock is induced by superantigen toxins, a diverse set of proteins secreted by Gram-positive staphylococcal and streptococcal bacterial strains that overstimulate the inflammatory response by orders of magnitude. The need to protect from superantigen toxins led to our discovery that in addition to the well-known MHC class II and T cell receptors, the principal costimulatory receptor, CD28, and its constitutively expressed coligand, B7-2 (CD86), previously thought to have only costimulatory function, are actually critical superantigen receptors. Binding of the superantigen into the homodimer interfaces of these costimulatory receptors greatly enhances B7-2/CD28 engagement, leading to excessive pro-inflammatory signaling. This finding led to the design of short receptor dimer interface mimetic peptides that block the binding of superantigen and thus protect from death. It then turned out that such a peptide will protect also from Gram-negative bacterial infection and from polymicrobial sepsis. One such CD28 mimetic peptide is advancing in a Phase 3 clinical trial to protect from lethal wound infections by flesh-eating bacteria. These host-oriented therapeutics target the human immune system itself, rendering pathogens less likely to become resistant.
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Ménoret A, Buturla JA, Xu MM, Svedova J, Kumar S, Rathinam VAK, Vella AT. T cell-directed IL-17 production by lung granular γδ T cells is coordinated by a novel IL-2 and IL-1β circuit. Mucosal Immunol 2018; 11:1398-1407. [PMID: 29907868 PMCID: PMC6668340 DOI: 10.1038/s41385-018-0037-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/29/2018] [Accepted: 04/20/2018] [Indexed: 02/04/2023]
Abstract
Immune-mediated lung is considered the result of an exacerbated innate injury immune response, although a role for adaptive lymphocytes is emerging. αβ T cells specific for S. aureus enterotoxin A orchestrate a Tγδ17 response during lung injury. However, the mechanism driving IL-17 production is unclear. Here, we show a role for IL-2 triggering IL-17 production by lung granular γδ T cells as IL-17 synthesis and neutrophil recruitment was reduced by IL-2 blocking mAbs in vitro and in vivo. Mass cytometry analysis revealed that lung γδ T cells responded directly to IL-2 as evident from STAT5 phosphorylation and RoRγt expression. IL-2 receptor blocking mAbs and JAK inhibition impaired STAT5 phosphorylation and IL-17 release. Moreover, inhalation of S. aureus enterotoxin A induced IL-2 secretion and caspase-1-dependent IL-1β activation to drive IL-17 production. This T-cell-mediated inflammasome-dependent IL-17 response is maximum when lung Tγδ17 cells were sequentially stimulated first with IL-2 then IL-1β. Interestingly, when IL-2 is given therapeutically to cancer patients it carries a known risk of lung injury that is largely indistinguishable from that seen in sepsis. Hence, this novel mechanism reveals therapeutic targets treating both acute lung injury and high-dose IL-2 toxicity in cancer.
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Affiliation(s)
- Antoine Ménoret
- Department of Immunology, UConn Health, 263 Farmington Avenue, Farmington, CT 06030, USA;,Institute for Systems Genomics, UConn Health, 400 Farmington Avenue, Farmington, CT 06030, USA and
| | - James A. Buturla
- Department of Internal Medicine, UConn Health, 263 Farmington Avenue, Farmington, CT 06030, USA
| | - Maria M. Xu
- Department of Immunology, UConn Health, 263 Farmington Avenue, Farmington, CT 06030, USA
| | - Julia Svedova
- Department of Immunology, UConn Health, 263 Farmington Avenue, Farmington, CT 06030, USA
| | - Sanjeev Kumar
- Department of Immunology, UConn Health, 263 Farmington Avenue, Farmington, CT 06030, USA
| | - Vijay A. K. Rathinam
- Department of Immunology, UConn Health, 263 Farmington Avenue, Farmington, CT 06030, USA
| | - Anthony T. Vella
- Department of Immunology, UConn Health, 263 Farmington Avenue, Farmington, CT 06030, USA
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Kuschnaroff L, De Belder K, Vandeputte M, Waer M. Factors involved in peripheral T cell tolerance: the extent of clonal deletion or clonal anergy depends on the age of the tolerized lymphocytes. Transpl Int 2018. [DOI: 10.1111/tri.1992.5.s1.589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Fisher EL, Otto M, Cheung GYC. Basis of Virulence in Enterotoxin-Mediated Staphylococcal Food Poisoning. Front Microbiol 2018; 9:436. [PMID: 29662470 PMCID: PMC5890119 DOI: 10.3389/fmicb.2018.00436] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/26/2018] [Indexed: 12/17/2022] Open
Abstract
The Staphylococcus aureus enterotoxins are a superfamily of secreted virulence factors that share structural and functional similarities and possess potent superantigenic activity causing disruptions in adaptive immunity. The enterotoxins can be separated into two groups; the classical (SEA-SEE) and the newer (SEG-SElY and counting) enterotoxin groups. Many members from both these groups contribute to the pathogenesis of several serious human diseases, including toxic shock syndrome, pneumonia, and sepsis-related infections. Additionally, many members demonstrate emetic activity and are frequently responsible for food poisoning outbreaks. Due to their robust tolerance to denaturing, the enterotoxins retain activity in food contaminated previously with S. aureus. The genes encoding the enterotoxins are found mostly on a variety of different mobile genetic elements. Therefore, the presence of enterotoxins can vary widely among different S. aureus isolates. Additionally, the enterotoxins are regulated by multiple, and often overlapping, regulatory pathways, which are influenced by environmental factors. In this review, we also will focus on the newer enterotoxins (SEG-SElY), which matter for the role of S. aureus as an enteropathogen, and summarize our current knowledge on their prevalence in recent food poisoning outbreaks. Finally, we will review the current literature regarding the key elements that govern the complex regulation of enterotoxins, the molecular mechanisms underlying their enterotoxigenic, superantigenic, and immunomodulatory functions, and discuss how these activities may collectively contribute to the overall manifestation of staphylococcal food poisoning.
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Affiliation(s)
- Emilie L Fisher
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Gordon Y C Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
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16
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Sun C, Wu L, Knopick PL, Bradley DS, Townes T, Terman DS. Sickle cells produce functional immune modulators and cytotoxics. Am J Hematol 2017. [PMID: 28646491 DOI: 10.1002/ajh.24836] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Sickle erythrocytes' (SSRBCs) unique physical adaptation to hypoxic conditions renders them able to home to hypoxic tumor niches in vivo, shut down tumor blood flow and induce tumoricidal responses. SSRBCs are also useful vehicles for transport of encapsulated drugs and oncolytic virus into hypoxic tumors with enhanced anti-tumor effects. In search of additional modes for arming sickle cells with cytotoxics, we turned to a lentiviral β-globin vector with optimized Locus Control Region/β-globin coding region/promoter/enhancers. We partially replaced the β-globin coding region of this vector with genes encoding T cell cytolytics, perforin and granzyme or immune modulating superantigens SEG and SEI. These modified vectors efficiently transduced Sca+ ckit- Lin- hematopoietic stem cells (HSCs) from humanized sickle cell knockin mice. Irradiated mice reconstituted with these HSCs displayed robust expression of transgenic RNAs and proteins in host sickle cells that was sustained for more than 10 months. SSRBCs from reconstituted mice harboring SEG/SEI transgenes induced robust proliferation and a prototypical superantigen-induced cytokine reaction when exposed to human CD4+/CD8+ cells. The β-globin lentiviral vector therefore produces a high level of functional, erythroid-specific immune modulators and cytotoxics that circulate without toxicity. Coupled with their unique ability to target and occlude hypoxic tumor vessels these armed SSRBCs constitute a potentially useful tool for treatment of solid tumors.
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Affiliation(s)
- Chiao‐Wang Sun
- Department of Biochemistry and Molecular GeneticsUniversity of Alabama at Birmingham, School of MedicineBirmingham Alabama
| | - Li‐Chen Wu
- Department of Biochemistry and Molecular GeneticsUniversity of Alabama at Birmingham, School of MedicineBirmingham Alabama
| | - Peter L. Knopick
- Department of Biomedical SciencesUniversity of North Dakota School of Medicine and Health SciencesGrand Forks North Dakota
| | - David S. Bradley
- Department of Biomedical SciencesUniversity of North Dakota School of Medicine and Health SciencesGrand Forks North Dakota
| | - Tim Townes
- Department of Biochemistry and Molecular GeneticsUniversity of Alabama at Birmingham, School of MedicineBirmingham Alabama
| | - David S. Terman
- Department of Biochemistry and Molecular GeneticsUniversity of Alabama at Birmingham, School of MedicineBirmingham Alabama
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17
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Reddy PN, Srirama K, Dirisala VR. An Update on Clinical Burden, Diagnostic Tools, and Therapeutic Options of Staphylococcus aureus. Infect Dis (Lond) 2017; 10:1179916117703999. [PMID: 28579798 PMCID: PMC5443039 DOI: 10.1177/1179916117703999] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 03/18/2017] [Indexed: 12/26/2022] Open
Abstract
Staphylococcus aureus is an important pathogen responsible for a variety of diseases ranging from mild skin and soft tissue infections, food poisoning to highly serious diseases such as osteomyelitis, endocarditis, and toxic shock syndrome. Proper diagnosis of pathogen and virulence factors is important for providing timely intervention in the therapy. Owing to the invasive nature of infections and the limited treatment options due to rampant spread of antibiotic-resistant strains, the trend for development of vaccines and antibody therapy is increasing at rapid rate than development of new antibiotics. In this article, we have discussed elaborately about the host-pathogen interactions, clinical burden due to S aureus infections, status of diagnostic tools, and treatment options in terms of prophylaxis and therapy.
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18
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Li Y, Deng H, Shi PD, Xu DD, Zhang LL, Zhang L, Huang JH. Toxic effects of seu are different from those of other staphylococcal enterotoxins. Am J Transl Res 2017; 9:1618-1629. [PMID: 28469769 PMCID: PMC5411912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/13/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND/PURPOSE Staphylococcal enterotoxins (SEs) are soluble extracellular proteins excreted by Staphylococcal bacterial strains, sharing similar structures and virulence. More than 20 genotypes of SEs have been identified, but the toxicity of some new SEs is still unclear. METHODS In this study, we assessed the toxicity effects of six recombinant SEs (rSEA, rSEO, rSEG, rSEK, rSEU and rSEQ) on Balb/c mice by reverse transcription-polymerase chain reaction (RT-PCR)-based methods and enzyme activity detection. RESULTS Except rSEU, the other five SEs resulted in systemic inflammatory responses with a significant increase of spleen and liver index and decrease of thymus index. SEs enhanced the enzyme activities of liver POD, T-SOD, LDH but reduced the activity of liver GSH-PX. The transcription levels of five cytokines were all down-regulated by rSEA, rSEG and rSEQ at a dose of 20 ng/g, which was coincided with the results of Caspase 3 level. The transcription and expression of IFN-γ, IL-4, IL-6, and TNF-α involved in inflammatory response were significantly up-regulated by rSEs at a low dose (20 ng/mL) except rSEU in vitro and in vivo. CONCLUSION Our results reveals that the rSEA, rSEO, rSEG, rSEK, and rSEQ have cytotoxicity and superantigenicity for Balb/c mice except the rSEU enterotoxin.
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Affiliation(s)
- Yi Li
- School of Life Sciences, Tianjin UniversityTianjin 300072, China
| | - Hui Deng
- School of Life Sciences, Tianjin UniversityTianjin 300072, China
| | - Pei-Dian Shi
- School of Life Sciences, Tianjin UniversityTianjin 300072, China
| | - Dan-Dan Xu
- School of Life Sciences, Tianjin UniversityTianjin 300072, China
| | - Li-Lin Zhang
- School of Life Sciences, Tianjin UniversityTianjin 300072, China
| | - Lei Zhang
- School of Life Sciences, Tianjin UniversityTianjin 300072, China
| | - Jin-Hai Huang
- School of Life Sciences, Tianjin UniversityTianjin 300072, China
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19
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Kaempfer R, Popugailo A, Levy R, Arad G, Hillman D, Rotfogel Z. Bacterial superantigen toxins induce a lethal cytokine storm by enhancing B7-2/CD28 costimulatory receptor engagement, a critical immune checkpoint. RECEPTORS & CLINICAL INVESTIGATION 2017; 4:e1500. [PMID: 28286804 PMCID: PMC5341606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Formation of the costimulatory axis between the B7-2 and CD28 coreceptors is critical for T-cell activation. Superantigens, Gram-positive bacterial virulence factors, cause toxic shock and sepsis by hyperinducing inflammatory cytokines. We report a novel role for costimulatory receptors CD28 and B7-2 as obligatory receptors for superantigens, rendering them therapeutic targets. We show that by engaging not only CD28 but also its coligand B7-2 directly, superantigens potently enhance the interaction between B7-2 and CD28, inducing thereby T-cell hyperactivation. Using a conserved twelve amino-acid domain, superantigens engage both B7-2 and CD28 at their homodimer interfaces, sites far removed from where these receptors interact, implying that inflammatory signaling can be controlled through the receptor homodimer interfaces. Short B7-2 and CD28 dimer interface mimetic peptides bind diverse superantigens, prevent superantigen binding to cell-surface B7-2 or CD28, attenuate inflammatory cytokine overexpression, and protect mice from lethal superantigen challenge. Thus, superantigens induce a cytokine storm by mediating not only the interaction between MHC-II molecule and T-cell receptor but critically, by promoting B7-2/CD28 coreceptor engagement, forcing the principal costimulatory axis to signal excessively. Our findings highlight the B7/CD28 interaction as a bottleneck in signaling for expression of inflammatory cytokines. B7-2 and CD28 homodimer interface mimetic peptides prevent superantigen lethality by blocking the superantigen-host costimulatory receptor interaction.
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Affiliation(s)
- Raymond Kaempfer
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, 9112102 Jerusalem, Israel
| | - Andrey Popugailo
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, 9112102 Jerusalem, Israel
| | - Revital Levy
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, 9112102 Jerusalem, Israel
| | - Gila Arad
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, 9112102 Jerusalem, Israel
| | - Dalia Hillman
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, 9112102 Jerusalem, Israel
| | - Ziv Rotfogel
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, 9112102 Jerusalem, Israel
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20
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Superantigens hyperinduce inflammatory cytokines by enhancing the B7-2/CD28 costimulatory receptor interaction. Proc Natl Acad Sci U S A 2016; 113:E6437-E6446. [PMID: 27708164 DOI: 10.1073/pnas.1603321113] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Full T-cell activation requires interaction between the costimulatory receptors B7-2 and CD28. By binding CD28, bacterial superantigens elicit harmful inflammatory cytokine overexpression through an unknown mechanism. We show that, by engaging not only CD28 but also its coligand B7-2 directly, superantigens potently enhance the avidity between B7-2 and CD28, inducing thereby T-cell hyperactivation. Using the same 12-aa β-strand-hinge-α-helix domain, superantigens engage both B7-2 and CD28 at their homodimer interfaces, areas remote from where these coreceptors interact, implying that inflammatory signaling can be controlled through the receptor homodimer interfaces. Short B7-2 dimer interface mimetic peptides bind diverse superantigens, prevent superantigen binding to cell-surface B7-2 or CD28, attenuate inflammatory cytokine overexpression, and protect mice from lethal superantigen challenge. Thus, superantigens induce a cytokine storm not only by mediating the interaction between MHC-II molecule and T-cell receptor but also, critically, by promoting B7-2/CD28 coreceptor engagement, forcing the principal costimulatory axis to signal excessively. Our results reveal a role for B7-2 as obligatory receptor for superantigens. B7-2 homodimer interface mimotopes prevent superantigen lethality by blocking the superantigen-host costimulatory receptor interaction.
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21
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Lorenzo D, Duarte A, Mundiñano J, Berguer P, Nepomnaschy I, Piazzon I. A B-Cell Superantigen Induces the Apoptosis of Murine and Human Malignant B Cells. PLoS One 2016; 11:e0162456. [PMID: 27603942 PMCID: PMC5014328 DOI: 10.1371/journal.pone.0162456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 08/23/2016] [Indexed: 11/18/2022] Open
Abstract
B-cell superantigens (Sags) bind to conserved sites of the VH or VL regions of immunoglobulin molecules outside their complementarity-determining regions causing the apoptosis of normal cognate B cells. No attempts to investigate whether B-cell Sags are able to induce the apoptosis of cognate malignant B cells were reported. In the present study we show that protein L (PpL), secreted by Finegoldia magna, a B-cell Sag which interacts with κ+ bearing cells, induces the apoptosis of murine and human κ+ lymphoma B cells both in vitro and in vivo. Apoptosis was not altered by caspase-8 inhibitor. No alterations in the levels of Bid, Fas and Fas-L were found suggesting that PpL does not activate the extrinsic pathway of apoptosis. The involvement of the intrinsic pathway was clearly indicated by: i) alterations in mitochondrial membrane potential (ΔΨm) both in murine and human lymphoma cells exposed to PpL; ii) decreased levels of apoptosis in the presence of caspase-9 inhibitor; iii) significant increases of Bim and Bax protein levels and downregulation of Bcl-2; iv) the translocation from the cytoplasm to the mitochondria of Bax and Bim pro-apoptotic proteins and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor and v) the translocation of Bcl-2 protein from the mitochondria to the cytosol and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor. The possibility of a therapeutic use of Sags in lymphoma/leukemia B cell malignancies is discussed.
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MESH Headings
- Adolescent
- Animals
- Annexin A5/metabolism
- Apoptosis/immunology
- B-Lymphocytes/drug effects
- B-Lymphocytes/immunology
- B-Lymphocytes/pathology
- B7-2 Antigen/metabolism
- Bacterial Proteins/immunology
- Bcl-2-Like Protein 11/metabolism
- Burkitt Lymphoma/genetics
- Burkitt Lymphoma/immunology
- Burkitt Lymphoma/pathology
- Caspase 8/metabolism
- Caspase 9/metabolism
- Caspase Inhibitors/pharmacology
- Cell Line, Tumor
- Cytosol/metabolism
- DNA, Neoplasm/metabolism
- DNA-Binding Proteins/immunology
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Immunoglobulin M/metabolism
- Immunoglobulin kappa-Chains/metabolism
- Lymphoma, B-Cell/genetics
- Lymphoma, B-Cell/immunology
- Lymphoma, B-Cell/pathology
- Male
- Membrane Potential, Mitochondrial/drug effects
- Mice, Inbred BALB C
- Mitochondria/drug effects
- Mitochondria/metabolism
- Protein Transport
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Signal Transduction/drug effects
- Superantigens/immunology
- bcl-2-Associated X Protein/genetics
- bcl-2-Associated X Protein/metabolism
- fas Receptor/genetics
- fas Receptor/metabolism
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Affiliation(s)
- Daniela Lorenzo
- IMEX-CONICET, Academia Nacional de Medicina de Buenos Aires, CABA, Argentina
| | - Alejandra Duarte
- IMEX-CONICET, Academia Nacional de Medicina de Buenos Aires, CABA, Argentina
| | - Juliana Mundiñano
- IMEX-CONICET, Academia Nacional de Medicina de Buenos Aires, CABA, Argentina
| | - Paula Berguer
- Fundación Instituto Leloir, IIBBA, CONICET, Buenos Aires, Argentina
| | - Irene Nepomnaschy
- IMEX-CONICET, Academia Nacional de Medicina de Buenos Aires, CABA, Argentina
| | - Isabel Piazzon
- IMEX-CONICET, Academia Nacional de Medicina de Buenos Aires, CABA, Argentina
- * E-mail:
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22
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Gill R, Jen KL, McCabe MJJ, Rosenspire A. Dietary n-3 PUFAs augment caspase 8 activation in Staphylococcal aureus enterotoxin B stimulated T-cells. Toxicol Appl Pharmacol 2016; 309:141-8. [PMID: 27614254 DOI: 10.1016/j.taap.2016.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/19/2016] [Accepted: 09/02/2016] [Indexed: 10/21/2022]
Abstract
Epidemiological studies have linked consumption of n-3 PUFAs with a variety of beneficial health benefits, particularly with respect to putative anti-inflammatory effects. Unfortunately, many of these results remain somewhat controversial because in most instances there has not been a linkage to specific molecular mechanisms. For instance, dietary exposure to low levels of mercury has been shown to be damaging to neural development, but concomitant ingestion of n-3 PUFAs as occurs during consumption of fish, has been shown to counteract the detrimental effects. As the mechanisms mediating the neurotoxicity of environmental mercury are not fully delineated, it is difficult to conceptualize a testable molecular mechanism explaining how n-3 PUFAs negate its neurotoxic effects. However, environmental exposure to mercury also has been linked to increased autoimmunity. By way of a molecular understanding of this immuno-toxic association, disruption of CD95 signaling is well established as a triggering factor for autoimmunity, and we have previously shown that environmentally relevant in vitro and dietary exposures to mercury interfere with CD95 signaling. In particular we have shown that activation of caspase 8, as well as downstream activation of caspase 3, in response to CD95 agonist stimulation is depressed by mercury. More recently we have shown in vitro that the n-3 PUFA docosahexaenoic acid counteracts the negative effect of mercury on CD95 signaling by restoring caspase activity. We hypothesized that concomitant ingestion of n-3 PUFAs with mercury might be protective from the immuno-toxic effects of mercury, as it is with mercury's neuro-toxic effects, and in the case of immuno-toxicity this would be related to restoration of CD95 signal strength. We now show that dietary ingestion of n-3 PUFAs generally promotes CD95 signaling by upregulating caspase 8 activation. Apart from accounting for the ability of n-3 PUFAs to specifically counteract autoimmune sequelae of mercury exposure, this novel finding for the first time suggests a testable molecular mechanism explaining the overall anti-inflammatory properties of n-3 PUFAs.
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Affiliation(s)
- R Gill
- Department of Immunology and Microbiology, Wayne State University, Detroit, MI, United States
| | - K L Jen
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI, United States; Center for Urban Responses to Environmental Stressors (CURES), Wayne State University, Detroit, MI, United States
| | - M J J McCabe
- Department of Environmental Medicine, University of Rochester, Rochester, NY, United States
| | - A Rosenspire
- Department of Immunology and Microbiology, Wayne State University, Detroit, MI, United States; Center for Urban Responses to Environmental Stressors (CURES), Wayne State University, Detroit, MI, United States.
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23
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Yasuda S, Nagaki M, Moriwaki H. Staphylococcal enterotoxin B induces hepatic injury and lethal shock in endotoxin-resistant C3H/HeJ mice despite a deficient macrophage response. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/09680519020080040201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Bacterial toxins, including endotoxin/LPS as well as superantigens, are major causative agents of multi-organ failure associated with sepsis and liver disease. However, the precise mechanisms initiating cell activation by the toxins have not been clarified. We compared lethal shock and cytokine production in response to LPS with responses to the superantigen staphylococcal enterotoxin B (SEB) in both LPS-responsive C3H/HeN mice and LPS-hyporesponsive C3H/HeJ mice treated with D-galactosamine (GalN). LPS was not lethal and did not induce production of TNF-α in C3H/HeJ mice. In contrast, SEB produced lethal shock associated with liver failure and induced cytokines such as TNF-α, IFN-γ, and IL-2 in both C3H/HeN and C3H/HeJ mice. Peritoneal macrophages from C3H/HeJ mice did not produce TNF-α in vitro in response to SEB or LPS. However, no significant difference was observed in production of TNF-α in response to stimulation in vitro by SEB between C3H/HeN and C3H/HeJ splenic lymphocytes. We have demonstrated that SEB causes lethal toxicity associated with liver injury in LPS-hyporesponsive C3H/HeJ mice and that as the underlying mechanism, the normal T-cell function in these mice still maintained the sensitivity to SEB since the genetic defect of C3H/HeJ mice unresponsive to LPS and SEB is restricted in macrophages/monocytes and does not extend to T cells.
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Affiliation(s)
- Shigeo Yasuda
- First Department of Internal Medicine, Gifu University School of Medicine, Gifu, Japan
| | - Masahito Nagaki
- First Department of Internal Medicine, Gifu University School of Medicine, Gifu, Japan, -u.ac.jp
| | - Hisataka Moriwaki
- First Department of Internal Medicine, Gifu University School of Medicine, Gifu, Japan
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24
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Chapes S, Beharka A. Lipopolysaccharide is required for the lethal effects of enterotoxin B after D-galactosamine sensitization. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/096805199500200406] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We tested the D-galactosamine sensitization model with staphylococcal enterotoxin B (SEB). LPS was required for the lethal effects of SEB in D-galactosamine sensitized mice. Only two (2/62) among the C3HeB/FeJ (H-2k), Balb/c (H-2d) and C57BL/6J (H-2b) mice died in response to SEB in the absence of LPS whereas injection of SEB and minimally lethal concentrations of LPS became highly toxic. Similar to LPS, the lethal effect of SEB was dependent on the mouse strain used. Mouse strains more sensitive to the effects of LPS (Balb/c and C57BL/6J) were also more sensitive to the effects of SEB in comparison to C3H mice when equivalent doses of LPS and SEB were used. Among Balb/c and C3HeB/FeJ but not C57BL/6J mice, SEB (20 μg) potentiated the lethal effects of LPS at low doses (0.1 μg LPS), but had an apparent protective effect at high doses (1 μg LPS). Lastly, there was an inverse correlation between pathogenesis and serum IL-2 concentrations and splenic T cell activation in C3H mice. However, macrophage mobilization did correlate with lethality. Therefore, some questions remain about the mechanisms involved in the D-galactosamine/SEB pathogenesis model. We conclude that when sensitizing mice with D-galactosamine and assessing the lethal effects of SEB, endotoxin contamination must be assessed.
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Affiliation(s)
- S.K. Chapes
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - A.A. Beharka
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
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25
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Kong C, Neoh HM, Nathan S. Targeting Staphylococcus aureus Toxins: A Potential form of Anti-Virulence Therapy. Toxins (Basel) 2016; 8:toxins8030072. [PMID: 26999200 PMCID: PMC4810217 DOI: 10.3390/toxins8030072] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/03/2016] [Accepted: 03/10/2016] [Indexed: 01/01/2023] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen and the leading cause of a wide range of severe clinical infections. The range of diseases reflects the diversity of virulence factors produced by this pathogen. To establish an infection in the host, S. aureus expresses an inclusive set of virulence factors such as toxins, enzymes, adhesins, and other surface proteins that allow the pathogen to survive under extreme conditions and are essential for the bacteria’s ability to spread through tissues. Expression and secretion of this array of toxins and enzymes are tightly controlled by a number of regulatory systems. S. aureus is also notorious for its ability to resist the arsenal of currently available antibiotics and dissemination of various multidrug-resistant S. aureus clones limits therapeutic options for a S. aureus infection. Recently, the development of anti-virulence therapeutics that neutralize S. aureus toxins or block the pathways that regulate toxin production has shown potential in thwarting the bacteria’s acquisition of antibiotic resistance. In this review, we provide insights into the regulation of S. aureus toxin production and potential anti-virulence strategies that target S. aureus toxins.
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Affiliation(s)
- Cin Kong
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia.
| | - Hui-min Neoh
- UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia, 56000 Cheras, Kuala Lumpur, Malaysia.
| | - Sheila Nathan
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia.
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26
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Use of biotin-labeled IgY overcomes protein A interference in immunoassays involving Staphylococcus aureus antigens. ANN MICROBIOL 2015. [DOI: 10.1007/s13213-014-1029-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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27
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Dutta K, Varshney AK, Franklin MC, Goger M, Wang X, Fries BC. Mechanisms mediating enhanced neutralization efficacy of staphylococcal enterotoxin B by combinations of monoclonal antibodies. J Biol Chem 2015; 290:6715-30. [PMID: 25572397 DOI: 10.1074/jbc.m114.630715] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Staphylococcal enterotoxin B (SEB) is a superantigen that cross-links the major histocompatibility complex class II and specific V-β chains of the T-cell receptor, thus forming a ternary complex. Developing neutralizing mAb to disrupt the ternary complex and abrogate the resulting toxicity is a major therapeutic challenge because SEB is effective at very low concentrations. We show that combining two SEB-specific mAbs enhances their efficacy, even though one of the two mAbs by itself has no effect on neutralization. Crystallography was employed for fine-mapping conformational epitopes in binary and ternary complexes between SEB and Fab fragments. NMR spectroscopy was used to validate and identify subtle allosteric changes induced by mAbs binding to SEB. The mapping of epitopes established that a combination of different mAbs can enhance efficacy of mAb-mediated protection from SEB induced lethal shock by two different mechanisms: one mAb mixture promoted clearance of the toxin both in vitro and in vivo by FcR-mediated cross-linking and clearance, whereas the other mAb mixture induced subtle allosteric conformational changes in SEB that perturbed formation of the SEB·T-cell receptor·major histocompatibility complex class II trimer. Finally structural information accurately predicted mAb binding to other superantigens that share conformational epitopes with SEB. Fine mapping of conformational epitopes is a powerful tool to establish the mechanism and optimize the action of synergistic mAb combinations.
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Affiliation(s)
- Kaushik Dutta
- From the New York Structural Biology Center, New York, New York 10027,
| | - Avanish K Varshney
- the Department of Medicine and Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11790, and the Department of Medicine, Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461
| | | | - Michael Goger
- From the New York Structural Biology Center, New York, New York 10027
| | - Xiaobo Wang
- the Department of Medicine, Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Bettina C Fries
- the Department of Medicine and Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11790, and the Department of Medicine, Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461
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Carney BC, Ortiz RT, Bullock RM, Prindeze NJ, Moffatt LT, Robson MC, Shupp JW. Reduction of a multidrug-resistant pathogen and associated virulence factors in a burn wound infection model: further understanding of the effectiveness of a hydroconductive dressing. EPLASTY 2014; 14:e45. [PMID: 25525484 PMCID: PMC4264520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Drawtex's ability to remove pathogens and associated virulence factors has been demonstrated in vitro. A model of burn wound infection was used to characterize the in vivo impact of this dressing on infection and wound healing. METHODS Paired burn wounds were created on the dorsum of Sprague Dawley rats and were inoculated with methicillin-resistant Staphylococcus aureus (MRSA). Animals were divided into 2 groups, half with wounds that received experimental dressing and the remaining half with control dressing-treated wounds. Dressings remained in place through 3, 6, 9, or 14 days after injury, and methicillin-resistant S aureus and virulence factors were quantified. Laser Doppler imaging was used to examine wound perfusion, and local host immune response was assessed through the quantification of mRNA expression. RESULTS By day 3, less methicillin-resistant S aureus was measured in wounds treated with experimental-dressing compared to control-dressing wounds. Quantities remained lower in the experimental group through day 14 (P < .001). More methicillin-resistant S aureus was quantified in the experimental dressing itself than in control dressing at all time points (P < .05). Experimental dressing-treated wounds contained less toxic shock syndrome toxin 1 and Panton-Valentine leukocidin than controls (P < .01) on days 6, 9, and 14. Induction of toll-like receptor 2, NOD-like receptor family, pyrin domain containing 3, and interleukin 6 was significantly lower in experimental-dressing treated wounds than in controls on days 6 and 9 (P < .05). CONCLUSIONS The hydroconductive dressing provided a significant reduction in pathogen and virulence factors compared to a control dressing. As a result of clearance of virulence factors from the wound bed, a requisite alteration in host innate immune response was observed.
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Affiliation(s)
- Bonnie C. Carney
- Firefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Rachel T. Ortiz
- Firefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Rachael M. Bullock
- Firefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Nicholas J. Prindeze
- Firefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Lauren T. Moffatt
- Firefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | | | - Jeffrey W. Shupp
- Firefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
- The Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC
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The bullseye synapse formed between CD4+ T-cell and staphylococcal enterotoxin B-pulsed dendritic cell is a suppressive synapse in T-cell response. Immunol Cell Biol 2014; 93:99-110. [PMID: 25287444 DOI: 10.1038/icb.2014.76] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/15/2014] [Accepted: 08/18/2014] [Indexed: 01/05/2023]
Abstract
The immunological synapse (IS) is a supermolecular activation cluster formed between T cells and antigen-presenting cells. Although diverse IS structures have been reported, the function of the IS in T-cell activation remains unclear. Here, we found that the bullseye IS, one of IS types at the interface of CD4(+) T cells and staphylococcal enterotoxin B-pulsed dendritic cells, suppressed CD4(+) T-cell activation, whereas multifocal IS, another synapse type, stimulated CD4(+) T-cell activation. Consistent with these results, bullseye IS formation was accompanied by a low-level calcium response in T cells and a loss of T-cell receptor signalling molecules from the synapse, whereas multifocal IS exhibited the opposite. Furthermore, we found that CD4(+)CD25(+) regulatory T cells (T(regs)) more efficiently formed bullseye IS and promoted bullseye IS formation in CD4(+) CD25(-) T cells. Cytotoxic T-lymphocyte antigen-4 (CTLA-4), an inhibitory molecule expressed continuously on T(regs), was localised in bullseye IS. Moreover, blocking CTLA-4 reduced the percentage of bullseye IS formation and promoted T-cell activation. Our data thus indicate that bullseye IS formation is mediated by CTLA-4, and may negatively control T-cell activation as a suppressive synapse.
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Prevention of adverse events of interferon γ gene therapy by gene delivery of interferon γ-heparin-binding domain fusion protein in mice. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2014; 1:14023. [PMID: 26015966 PMCID: PMC4362348 DOI: 10.1038/mtm.2014.23] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 05/02/2014] [Indexed: 01/09/2023]
Abstract
Sustained gene delivery of interferon (IFN) γ can be an effective treatment, but our previous study showed high levels of IFNγ-induced adverse events, including the loss of body weight. These unwanted events could be reduced by target-specific delivery of IFNγ after in vivo gene transfer. To achieve this, we selected the heparin-binding domain (HBD) of extracellular superoxide dismutase as a molecule to anchor IFNγ to the cell surface. We designed three IFNγ derivatives, IFNγ-HBD1, IFNγ-HBD2, and IFNγ-HBD3, each of which had 1, 2, or 3 HBDs, respectively. Each plasmid-encoding fusion proteins was delivered to the liver, a model target in this study, by hydrodynamic tail vein injection. The serum concentration of IFNγ-HBD2 and IFNγ-HBD3 after gene delivery was lower than that of IFNγ or IFNγ-HBD1. Gene delivery of IFNγ-HBD2, but not of IFNγ-HBD3, effectively increased the mRNA expression of IFNγ-inducible genes in the liver, suggesting liver-specific distribution of IFNγ-HBD2. Gene delivery of IFNγ-HBD2-suppressed tumor growth in the liver as efficiently as that of IFNγ with much less symptoms of adverse effects. These results indicate that the adverse events of IFNγ gene transfer can be prevented by gene delivery of IFNγ-HBD2, a fusion protein with high cell surface affinity.
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Principato M, Qian BF. Staphylococcal enterotoxins in the etiopathogenesis of mucosal autoimmunity within the gastrointestinal tract. Toxins (Basel) 2014; 6:1471-89. [PMID: 24776983 PMCID: PMC4052247 DOI: 10.3390/toxins6051471] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 04/18/2014] [Accepted: 04/22/2014] [Indexed: 01/22/2023] Open
Abstract
The staphylococcal enterotoxins (SEs) are the products of Staphylococcus aureus and are recognized as the causative agents of classical food poisoning in humans following the consumption of contaminated food. While illness evoked by ingestion of the SE or its producer organism in tainted food are often self-limited, our current understanding regarding the evolution of S. aureus provokes the utmost concern. The organism and its associated toxins, has been implicated in a wide variety of disease states including infections of the skin, heart, sinuses, inflammatory gastrointestinal disease, toxic shock, and Sudden Infant Death Syndrome. The intricate relationship between the various subsets of immunocompetent T cells and accessory cells and the ingested material found within the gastrointestinal tract present daunting challenges to the maintenance of immunologic homeostasis. Dysregulation of the intricate balances within this environment has the potential for extreme consequences within the host, some of which are long-lived. The focus of this review is to evaluate the relevance of staphylococcal enterotoxin in the context of mucosal immunity, and the underlying mechanisms that contribute to the pathogenesis of gastrointestinal autoimmune disease.
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Affiliation(s)
- MaryAnn Principato
- Division of Toxicology, Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 8301 Muirkirk Road, Laurel, MD 20708, USA.
| | - Bi-Feng Qian
- Commissioner's Fellowship Program, Division of Toxicology, Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 8301 Muirkirk Road, Laurel, MD 20708, USA.
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Prindeze NJ, Amundsen BM, Pavlovich AR, Paul DW, Carney BC, Moffatt LT, Shupp JW. Staphylococcal superantigens and toxins are detectable in the serum of adult burn patients. Diagn Microbiol Infect Dis 2014; 79:303-7. [PMID: 24809857 DOI: 10.1016/j.diagmicrobio.2014.01.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 01/23/2014] [Accepted: 01/24/2014] [Indexed: 01/25/2023]
Abstract
Bacterial infection in burn patients is still a devastating contributor to morbidity and mortality. Little is known regarding the presence of staphylococcal toxins in the burn-injured patient. The aim of this study was to characterize the prevalence of several of these toxins and their relationship to clinical metrics and mortality in burn patients. Levels of exotoxins staphylococcal enterotoxin A (SEA), staphylococcal enterotoxin B, toxic shock syndrome toxin 1 (TSST-1), and α-hemolysin were assayed from the serum of 207 adult burn patients aged 16-92 years. Clinical, demographic, and microbiological data from these patients were then compared to toxin levels. Staphylococcal exotoxins α-hemolysin and SEA were present in 45% and 25% of the population, respectively. Bacterial cultures concomitantly showed a high prevalence of Staphylococcus aureus in 48% of patients, of which 59% were methicillin resistant. Several metrics may be predictive of high toxin concentrations of α-hemolysin and TSST-1 and SEA including burn size, length of stay, and bacteremia. Mortality associations indicated that burn size, bacteremia, age, and the presence of α-hemolysin and SEA may be predictors of mortality. A high prevalence of staphylococcal toxin α-hemolysin and superantigens TSST-1 and SEA can be found in the circulation of the adult burn population. The presence of these toxins may contribute to the morbidity and mortality of the burn patient.
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Affiliation(s)
- Nicholas J Prindeze
- The Burn Center, Department of Surgery, MedStar Washington Hospital Center, MedStar Health Research Institute, 110 Irving Street NW, Washington, DC 20010-2975
| | - Bethany M Amundsen
- The Burn Center, Department of Surgery, MedStar Washington Hospital Center, MedStar Health Research Institute, 110 Irving Street NW, Washington, DC 20010-2975
| | - Anna R Pavlovich
- The Burn Center, Department of Surgery, MedStar Washington Hospital Center, MedStar Health Research Institute, 110 Irving Street NW, Washington, DC 20010-2975
| | - Dereck W Paul
- The Burn Center, Department of Surgery, MedStar Washington Hospital Center, MedStar Health Research Institute, 110 Irving Street NW, Washington, DC 20010-2975
| | - Bonnie C Carney
- The Burn Center, Department of Surgery, MedStar Washington Hospital Center, MedStar Health Research Institute, 110 Irving Street NW, Washington, DC 20010-2975
| | - Lauren T Moffatt
- The Burn Center, Department of Surgery, MedStar Washington Hospital Center, MedStar Health Research Institute, 110 Irving Street NW, Washington, DC 20010-2975
| | - Jeffrey W Shupp
- The Burn Center, Department of Surgery, MedStar Washington Hospital Center, MedStar Health Research Institute, 110 Irving Street NW, Washington, DC 20010-2975.
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Kim H, Darwish I, Monroy MF, Prockop DJ, Liles WC, Kain KC. Mesenchymal stromal (stem) cells suppress pro-inflammatory cytokine production but fail to improve survival in experimental staphylococcal toxic shock syndrome. BMC Immunol 2014; 15:1. [PMID: 24423010 PMCID: PMC3898056 DOI: 10.1186/1471-2172-15-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/10/2014] [Indexed: 12/02/2022] Open
Abstract
Background Toxic shock syndrome (TSS) is caused by an overwhelming host-mediated response to bacterial superantigens produced mainly by Staphylococcus aureus and Streptococcus pyogenes. TSS is characterized by aberrant activation of T cells and excessive release of pro-inflammatory cytokines ultimately resulting in capillary leak, septic shock, multiple organ dysfunction and high mortality rates. No therapeutic or vaccine has been approved by the U.S. Food and Drug Administration for TSS, and novel therapeutic strategies to improve clinical outcome are needed. Mesenchymal stromal (stem) cells (MSCs) are stromal cells capable of self-renewal and differentiation. Moreover, MSCs have immunomodulatory properties, including profound effects on activities of T cells and macrophages in specific contexts. Based on the critical role of host-derived immune mediators in TSS, we hypothesized that MSCs could modulate the host-derived proinflammatory response triggered by Staphylococcal enterotoxin B (SEB) and improve survival in experimental TSS. Methods Effects of MSCs on proinflammatory cytokines in peripheral blood were measured in wild-type C57BL/6 mice injected with 50 μg of SEB. Effects of MSCs on survival were monitored in fatal experimental TSS induced by consecutive doses of D-galactosamine (10 mg) and SEB (10 μg) in HLA-DR4 transgenic mice. Results Despite significantly decreasing serum levels of IL-2, IL-6 and TNF induced by SEB in wild-type mice, human MSCs failed to improve survival in experimental TSS in HLA-DR4 transgenic mice. Similarly, a previously described downstream mediator of human MSCs, TNF-stimulated gene 6 (TSG-6), did not significantly improve survival in experimental TSS. Furthermore, murine MSCs, whether unstimulated or pre-treated with IFNγ, failed to improve survival in experimental TSS. Conclusions Our results suggest that the immunomodulatory effects of MSCs are insufficient to rescue mice from experimental TSS, and that mediators other than IL-2, IL-6 and TNF are likely to play critical mechanistic roles in the pathogenesis of experimental TSS.
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Affiliation(s)
| | | | | | | | | | - Kevin C Kain
- Sandra A, Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, M5G 1 L7, Canada.
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Ramachandran G. Gram-positive and gram-negative bacterial toxins in sepsis: a brief review. Virulence 2014; 5:213-8. [PMID: 24193365 PMCID: PMC3916377 DOI: 10.4161/viru.27024] [Citation(s) in RCA: 233] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/28/2013] [Accepted: 10/31/2013] [Indexed: 12/31/2022] Open
Abstract
Bacterial sepsis is a major cause of fatality worldwide. Sepsis is a multi-step process that involves an uncontrolled inflammatory response by the host cells that may result in multi organ failure and death. Both gram-negative and gram-positive bacteria play a major role in causing sepsis. These bacteria produce a range of virulence factors that enable them to escape the immune defenses and disseminate to remote organs, and toxins that interact with host cells via specific receptors on the cell surface and trigger a dysregulated immune response. Over the past decade, our understanding of toxins has markedly improved, allowing for new therapeutic strategies to be developed. This review summarizes some of these toxins and their role in sepsis.
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Affiliation(s)
- Girish Ramachandran
- Center for Vaccine Development; Department of Medicine; University of Maryland School of Medicine; Baltimore, MD USA
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Busbee PB, Nagarkatti M, Nagarkatti PS. Natural indoles, indole-3-carbinol and 3,3'-diindolymethane, inhibit T cell activation by staphylococcal enterotoxin B through epigenetic regulation involving HDAC expression. Toxicol Appl Pharmacol 2014; 274:7-16. [PMID: 24200994 PMCID: PMC3874587 DOI: 10.1016/j.taap.2013.10.022] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/24/2013] [Accepted: 10/25/2013] [Indexed: 12/13/2022]
Abstract
Staphylococcal enterotoxin B (SEB) is a potent exotoxin produced by the Staphylococcus aureus. This toxin is classified as a superantigen because of its ability to directly bind with MHC-II class molecules followed by activation of a large proportion of T cells bearing specific Vβ-T cell receptors. Commonly associated with classic food poisoning, SEB has also been shown to induce toxic shock syndrome, and is also considered to be a potential biological warfare agent because it is easily aerosolized. In the present study, we assessed the ability of indole-3-carbinol (I3C) and one of its byproducts, 3,3'-diindolylmethane (DIM), found in cruciferous vegetables, to counteract the effects of SEB-induced activation of T cells in mice. Both I3C and DIM were found to decrease the activation, proliferation, and cytokine production by SEB-activated Vβ8(+) T cells in vitro and in vivo. Interestingly, inhibitors of histone deacetylase class I (HDAC-I), but not class II (HDAC-II), showed significant decrease in SEB-induced T cell activation and cytokine production, thereby suggesting that epigenetic modulation plays a critical role in the regulation of SEB-induced inflammation. In addition, I3C and DIM caused a decrease in HDAC-I but not HDAC-II in SEB-activated T cells, thereby suggesting that I3C and DIM may inhibit SEB-mediated T cell activation by acting as HDAC-I inhibitors. These studies not only suggest for the first time that plant-derived indoles are potent suppressors of SEB-induced T cell activation and cytokine storm but also that they may mediate these effects by acting as HDAC inhibitors.
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Affiliation(s)
- Philip B Busbee
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC 29208, USA
| | - Mitzi Nagarkatti
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC 29208, USA
| | - Prakash S Nagarkatti
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC 29208, USA.
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CD28: direct and critical receptor for superantigen toxins. Toxins (Basel) 2013; 5:1531-42. [PMID: 24022021 PMCID: PMC3798871 DOI: 10.3390/toxins5091531] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 08/30/2013] [Accepted: 09/05/2013] [Indexed: 01/16/2023] Open
Abstract
Every adaptive immune response requires costimulation through the B7/CD28 axis, with CD28 on T-cells functioning as principal costimulatory receptor. Staphylococcal and streptococcal superantigen toxins hyperstimulate the T-cell-mediated immune response by orders of magnitude, inducing a lethal cytokine storm. We show that to elicit an inflammatory cytokine storm and lethality, superantigens must bind directly to CD28. Blocking access of the superantigen to its CD28 receptor with peptides mimicking the contact domains in either toxin or CD28 suffices to protect mice effectively from lethal shock. Our finding that CD28 is a direct receptor of superantigen toxins broadens the scope of microbial pathogen recognition mechanisms.
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HLA-DO increases bacterial superantigen binding to human MHC molecules by inhibiting dissociation of class II-associated invariant chain peptides. Hum Immunol 2013; 74:1280-7. [PMID: 23756162 DOI: 10.1016/j.humimm.2013.05.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 05/17/2013] [Accepted: 05/29/2013] [Indexed: 11/22/2022]
Abstract
HLA-DO (H2-O in mice) is an intracellular non-classical MHC class II molecule (MHCII). It forms a stable complex with HLA-DM (H2-M in mice) and shapes the MHC class II-associated peptide repertoire. Here, we tested the impact of HLA-DO and H2-O on the binding of superantigens (SAgs), which has been shown previously to be sensitive to the structural nature of the class II-bound peptides. We found that the binding of staphylococcal enterotoxin (SE) A and B, as well as toxic shock syndrome toxin 1 (TSST-1), was similar on the HLA-DO(+) human B cell lines 721.45 and its HLA-DO(-) counterpart. However, overexpressing HLA-DO in MHC class II(+) HeLa cells (HeLa-CIITA-DO) improved binding of SEA and TSST-1. Accordingly, knocking down HLA-DO expression using specific siRNAs decreased SEA and TSST-1 binding. We tested directly the impact of the class II-associated invariant chain peptide (CLIP), which dissociation from MHC class II molecules is inhibited by overexpressed HLA-DO. Loading of synthetic CLIP on HLA-DR(+) cells increased SEA and TSST-1 binding. Accordingly, knocking down HLA-DM had a similar effect. In mice, H2-O deficiency had no impact on SAgs binding to isolated splenocytes. Altogether, our results demonstrate that the sensitivity of SAgs to the MHCII-associated peptide has physiological basis and that the effect of HLA-DO on SEA and TSST-1 is mediated through the inhibition of CLIP release.
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Ramachandran G, Tulapurkar ME, Harris KM, Arad G, Shirvan A, Shemesh R, Detolla LJ, Benazzi C, Opal SM, Kaempfer R, Cross AS. A peptide antagonist of CD28 signaling attenuates toxic shock and necrotizing soft-tissue infection induced by Streptococcus pyogenes. J Infect Dis 2013; 207:1869-77. [PMID: 23493729 DOI: 10.1093/infdis/jit104] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Staphylococcus aureus and group A Streptococcus pyogenes (GAS) express superantigen (SAg) exotoxin proteins capable of inducing lethal shock. To induce toxicity, SAgs must bind not only to the major histocompatibility complex II molecule of antigen-presenting cells and the variable β chain of the T-cell receptor but also to the dimer interface of the T-cell costimulatory receptor CD28. Here, we show that the CD28-mimetic peptide AB103 (originally designated "p2TA") protects mice from lethal challenge with streptococcal exotoxin A, as well as from lethal GAS bacterial infection in a murine model of necrotizing soft-tissue infection. Administration of a single dose of AB103 increased survival when given up to 5 hours after infection, reduced inflammatory cytokine expression and bacterial burden at the site of infection, and improved muscle inflammation in a dose-dependent manner, without compromising cellular and humoral immunity. Thus, AB103 merits further investigation as a potential therapeutic in SAg-mediated necrotizing soft-tissue infection.
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Affiliation(s)
- Girish Ramachandran
- Center for Vaccine Development, University of Maryland Medical School, Baltimore, Baltimore, MD 21201, USA
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Shupp JW, Ortiz RT, Moffatt LT, Jo DY, Randad PR, Njimoluh KL, Mauskar NA, Mino MJ, Amundsen B, Jordan MH. Treatment with an Oxazolidinone Antibiotic Inhibits Toxic Shock Syndrome Toxin-1 Production in MRSA-Infected Burn Wounds. J Burn Care Res 2013; 34:267-73. [DOI: 10.1097/bcr.0b013e318280e35a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Xiao Z, Wu L, Mo H, Kong T. Increased T Cell Chemotaxis Response to Staphylococcus Enterotoxin B Mediated Human Endothelial Cell Damage In Vitro. Scand J Immunol 2012; 75:147-56. [DOI: 10.1111/j.1365-3083.2011.02638.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chimeric anti-staphylococcal enterotoxin B antibodies and lovastatin act synergistically to provide in vivo protection against lethal doses of SEB. PLoS One 2011; 6:e27203. [PMID: 22102880 PMCID: PMC3216929 DOI: 10.1371/journal.pone.0027203] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 10/12/2011] [Indexed: 11/19/2022] Open
Abstract
Staphylococcal enterotoxin B (SEB) is one of a family of toxins secreted by Staphylococcus aureus that act as superantigens, activating a large fraction of the T-cell population and inducing production of high levels of inflammatory cytokines that can cause toxic shock syndrome (TSS) and death. Extracellular engagement of the TCR of T-cells and class II MHC of antigen presenting cells by SEB triggers the activation of many intracellular signaling processes. We engineered chimeric antibodies to block the extracellular engagement of cellular receptors by SEB and used a statin to inhibit intracellular signaling. Chimeric human-mouse antibodies directed against different neutralizing epitopes of SEB synergistically inhibited its activation of human T-cells in vitro. In the in vivo model of lethal toxic shock syndrome (TSS) in HLA-DR3 transgenic mice, two of these antibodies conferred significant partial protection when administered individually, but offered complete protection in a synergistic manner when given together. Similarly, in vivo, lovastatin alone conferred only partial protection from TSS similar to single anti-SEB antibodies. However, used in combination with one chimeric neutralizing anti-SEB antibody, lovastatin provided complete protection against lethal TSS in HLA-DR3 transgenic mice. These experiments demonstrate that in vivo protection against lethal doses of SEB can be achieved by a statin of proven clinical safety and chimeric human-mouse antibodies, agents now widely used and known to be of low immunogenicity in human hosts.
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Arad G, Levy R, Nasie I, Hillman D, Rotfogel Z, Barash U, Supper E, Shpilka T, Minis A, Kaempfer R. Binding of superantigen toxins into the CD28 homodimer interface is essential for induction of cytokine genes that mediate lethal shock. PLoS Biol 2011; 9:e1001149. [PMID: 21931534 PMCID: PMC3172200 DOI: 10.1371/journal.pbio.1001149] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 08/02/2011] [Indexed: 01/04/2023] Open
Abstract
Bacterial superantigens, a diverse family of toxins, induce an inflammatory cytokine storm that can lead to lethal shock. CD28 is a homodimer expressed on T cells that functions as the principal costimulatory ligand in the immune response through an interaction with its B7 coligands, yet we show here that to elicit inflammatory cytokine gene expression and toxicity, superantigens must bind directly into the dimer interface of CD28. Preventing access of the superantigen to CD28 suffices to block its lethality. Mice were protected from lethal superantigen challenge by short peptide mimetics of the CD28 dimer interface and by peptides selected to compete with the superantigen for its binding site in CD28. Superantigens use a conserved β-strand/hinge/α-helix domain of hitherto unknown function to engage CD28. Mutation of this superantigen domain abolished inflammatory cytokine gene induction and lethality. Structural analysis showed that when a superantigen binds to the T cell receptor on the T cell and major histocompatibility class II molecule on the antigen-presenting cell, CD28 can be accommodated readily as third superantigen receptor in the quaternary complex, with the CD28 dimer interface oriented towards the β-strand/hinge/α-helix domain in the superantigen. Our findings identify the CD28 homodimer interface as a critical receptor target for superantigens. The novel role of CD28 as receptor for a class of microbial pathogens, the superantigen toxins, broadens the scope of pathogen recognition mechanisms.
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Affiliation(s)
- Gila Arad
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Revital Levy
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Iris Nasie
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Dalia Hillman
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ziv Rotfogel
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Uri Barash
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Emmanuelle Supper
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Tomer Shpilka
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Adi Minis
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Raymond Kaempfer
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
- * E-mail:
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CD1d-independent activation of invariant natural killer T cells by staphylococcal enterotoxin B through major histocompatibility complex class II/T cell receptor interaction results in acute lung injury. Infect Immun 2011; 79:3141-8. [PMID: 21628519 DOI: 10.1128/iai.00177-11] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
There are two important mechanisms of activation of invariant natural killer T cells (iNKT cells) by microbes: direct activation of the invariant T-cell receptor (TCR) by microbial glycolipids presented by CD1d and indirect activation, mediated by the responses of antigen-presenting cells to microbes. In this study, we provide evidence for a novel CD1d-independent direct activation of iNKT cells involving a microbial protein superantigen presented in the context of major histocompatibility complex class II (MHC-II), which plays a critical role in pathogenesis, thereby redefining the role of iNKT cells. Intranasal exposure to staphylococcal enterotoxin B (SEB) in C57BL/6 wild-type mice caused acute lung injury (ALI) characterized by vascular leak, cytokine storm, and infiltration of mononuclear cells in the lungs. In contrast, the vascular leak and inflammation were decreased by ~50% in NKT cell-deficient Jα18(-/-) and CD1d(-/-) mice following SEB exposure, which was reversed following adoptive transfer of iNKT cells into CD1d(-/-) mice. In vitro, SEB could directly stimulate iNKT cells in a CD1d-independent manner via MHC-II/TCR interaction, specifically involving Vβ8. These studies not only demonstrate that iNKT cells can be activated directly by a bacterial protein superantigen independent of CD1d but also indicate that in addition to the conventional T cells, iNKT cells play a critical role in SEB-mediated ALI.
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Superantigens increase the survival of mice bearing T cell lymphomas by inducing apoptosis of neoplastic cells. PLoS One 2010; 5:e15694. [PMID: 21203530 PMCID: PMC3008744 DOI: 10.1371/journal.pone.0015694] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Accepted: 11/23/2010] [Indexed: 11/29/2022] Open
Abstract
Superantigens bind to major histocompatibility complex class II molecules and interact with T cells expressing a particular T cell receptor Vβ inducing a strong proliferation/deletion response of the superantigen-reactive T cells. However, there have been no attempts to investigate the ability of Sags to induce apoptosis in neoplastic T cells by signaling through the Vβ region of their TCR. In the present study we show that bacterial and MMTV-encoded superantigens induce the apoptosis of AKR/J cognate lymphoma T cells both in vitro and in vivo. The Fas-Fas-L pathway was shown to be involved in the apoptosis of lymphoma T cells induced by bacterial superantigens. In vivo exposure to bacterial superantigens was able to improve the survival of lymphoma bearing mice. Moreover, the permanent expression of a retroviral encoded superantigen induced the complete remission of an aggressive lymphoma in a high percentage of mice. The possibility of a therapeutic use of superantigens in lymphoma/leukemia T cell malignancies is discussed.
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Staphylococcal superantigen (TSST-1) mutant analysis reveals that t cell activation is required for biological effects in the rabbit including the cytokine storm. Toxins (Basel) 2010; 2:2272-88. [PMID: 22069685 PMCID: PMC3153295 DOI: 10.3390/toxins2092272] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 09/01/2010] [Accepted: 09/07/2010] [Indexed: 11/16/2022] Open
Abstract
Staphylococcal superantigens (sAgs), such as toxic shock syndrome toxin 1 (TSST-1), induce massive cytokine production, which may result in toxic shock syndrome (TSS) and sepsis. Recently, we reported that in vitro studies in human peripheral blood mononuclear cells (PBMC) do not reflect the immunological situation of the host, because after exposure to superantigens (sAgs) in vivo, mononuclear cells (MNC) leave the circulation and migrate to organs, e.g., the spleen, liver and lung. Our experimental model of choice is the rabbit because it is comparable to humans in its sensitivity to sAg. T cell activation has been assessed by lymphocyte proliferation and IL-2 gene expression after in vivo challenge with TSST-1 and the mutant antigens; expression of the genes of proinflammatory cytokines were taken as indicators for the inflammatory reaction after the combined treatment with TSST-1 and LPS. The question as to whether the biological activities of TSST-1, e.g., lymphocyte extravasation, toxicity and increased sensitivity to LPS, are mediated by T cell activation or activation by MHC II-only, are unresolved and results are contradictory. We have addressed this question by studying these reactions in vivo, with two TSST-1 mutants: one mutated at the MHC binding site (G31R) with reduced MHC binding with residual activity still present, and the other at the T cell binding site (H135A) with no residual function detectable. Here, we report that the mutant G31R induced all the biological effects of the wild type sAg, while the mutant with non-functional TCR binding did not retain any of the toxic effects, proving the pivotal role of T cells in this system.
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Lin CF, Chen CL, Huang WC, Cheng YL, Hsieh CY, Wang CY, Hong MY. Different types of cell death induced by enterotoxins. Toxins (Basel) 2010; 2:2158-76. [PMID: 22069678 PMCID: PMC3153280 DOI: 10.3390/toxins2082158] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 08/03/2010] [Indexed: 02/07/2023] Open
Abstract
The infection of bacterial organisms generally causes cell death to facilitate microbial invasion and immune escape, both of which are involved in the pathogenesis of infectious diseases. In addition to the intercellular infectious processes, pathogen-produced/secreted enterotoxins (mostly exotoxins) are the major weapons that kill host cells and cause diseases by inducing different types of cell death, particularly apoptosis and necrosis. Blocking these enterotoxins with synthetic drugs and vaccines is important for treating patients with infectious diseases. Studies of enterotoxin-induced apoptotic and necrotic mechanisms have helped us to create efficient strategies to use against these well-characterized cytopathic toxins. In this article, we review the induction of the different types of cell death from various bacterial enterotoxins, such as staphylococcal enterotoxin B, staphylococcal alpha-toxin, Panton-Valentine leukocidin, alpha-hemolysin of Escherichia coli, Shiga toxins, cytotoxic necrotizing factor 1, heat-labile enterotoxins, and the cholera toxin, Vibrio cholerae. In addition, necrosis caused by pore-forming toxins, apoptotic signaling through cross-talk pathways involving mitochondrial damage, endoplasmic reticulum stress, and lysosomal injury is discussed.
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Affiliation(s)
- Chiou-Feng Lin
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; (W.-C.H.); (Y.-L.C.); (C.-Y.H.); (C.-Y.W.); (M.-Y.H.)
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; (C.-L.C.)
- Author to whom correspondence should be addressed; ; Tel.: +886-06-235-3535 ext. 4240; Fax: +886-06-275-8781
| | - Chia-Ling Chen
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; (C.-L.C.)
| | - Wei-Ching Huang
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; (W.-C.H.); (Y.-L.C.); (C.-Y.H.); (C.-Y.W.); (M.-Y.H.)
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Yi-Lin Cheng
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; (W.-C.H.); (Y.-L.C.); (C.-Y.H.); (C.-Y.W.); (M.-Y.H.)
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Chia-Yuan Hsieh
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; (W.-C.H.); (Y.-L.C.); (C.-Y.H.); (C.-Y.W.); (M.-Y.H.)
| | - Chi-Yun Wang
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; (W.-C.H.); (Y.-L.C.); (C.-Y.H.); (C.-Y.W.); (M.-Y.H.)
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Ming-Yuan Hong
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; (W.-C.H.); (Y.-L.C.); (C.-Y.H.); (C.-Y.W.); (M.-Y.H.)
- Department of Emergency, National Cheng Kung University Hospital, Tainan 701, Taiwan
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Multiple roles of Staphylococcus aureus enterotoxins: pathogenicity, superantigenic activity, and correlation to antibiotic resistance. Toxins (Basel) 2010; 2:2117-31. [PMID: 22069676 PMCID: PMC3153285 DOI: 10.3390/toxins2082117] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2010] [Accepted: 08/09/2010] [Indexed: 12/03/2022] Open
Abstract
Heat-stable enterotoxins are the most notable virulence factors associated with Staphylococcus aureus, a common pathogen associated with serious community and hospital acquired diseases. Staphylococcal enterotoxins (SEs) cause toxic shock-like syndromes and have been implicated in food poisoning. But SEs also act as superantigens that stimulate T-cell proliferation, and a high correlation between these activities has been detected. Most of the nosocomial S. aureus infections are caused by methicillin-resistant S. aureus (MRSA) strains, and those resistant to quinolones or multiresistant to other antibiotics are emerging, leaving a limited choice for their control. This review focuses on these diverse roles of SE, their possible correlations and the influence in disease progression and therapy.
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The systemic and pulmonary immune response to staphylococcal enterotoxins. Toxins (Basel) 2010; 2:1898-912. [PMID: 22069664 PMCID: PMC3153275 DOI: 10.3390/toxins2071898] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 07/12/2010] [Indexed: 11/21/2022] Open
Abstract
In response to environmental cues the human pathogen Staphylococcus aureus synthesizes and releases proteinaceous enterotoxins. These enterotoxins are natural etiologic entities of severe food poisoning, toxic shock syndrome, and acute diseases. Staphylococcal enterotoxins are currently listed as Category B Bioterrorism Agents by the Center for Disease Control and Prevention. They are associated with respiratory illnesses, and may contribute to exacerbation of pulmonary disease. This likely stems from the ability of Staphylococcal enterotoxins to elicit powerful episodes of T cell stimulation resulting in release of pro-inflammatory cytokines. Here, we discuss the role of the immune system and potential mechanisms of disease initiation and progression.
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Lin Z, Kotler DP, Schlievert PM, Sordillo EM. Staphylococcal enterocolitis: forgotten but not gone? Dig Dis Sci 2010; 55:1200-7. [PMID: 19609675 DOI: 10.1007/s10620-009-0886-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Accepted: 06/19/2009] [Indexed: 12/27/2022]
Abstract
PURPOSE Staphylococcus aureus may cause antibiotic-associated diarrhea and enterocolitis, with or without preceding antibiotic use, in immunocompromised adults or infants, or individuals with predisposing conditions, but there is little appreciation of this condition clinically. CLINICAL DISEASE: The main clinical feature that helps to differentiate staphylococcal enterocolitis (SEC) from Clostridium difficile-associated diarrhea is large-volume, cholera-like diarrhea in the former case. A predominance of gram-positive cocci in clusters on gram stain of stool or biopsy specimens and the isolation of S. aureus as the dominant or sole flora support the diagnosis. PATHOGENESIS The pathogenesis of SEC requires the interaction of staphylococcal enterotoxins, which function as superantigens, with interstitial epithelial lymphocytes and intestinal epithelial cells (IECs). MANAGEMENT Most SEC represents recent S. aureus acquisition, so that improved infection prevention practices can reduce disease recurrence. Management should include aggressive fluid management and repletion and oral vancomycin.
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Affiliation(s)
- Zheng Lin
- Division of Gastroenterology, Department of Medicine, St. Luke's-Roosevelt Hospital Center, New York, NY 10025, USA
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Potent neutralization of staphylococcal enterotoxin B by synergistic action of chimeric antibodies. Infect Immun 2010; 78:2801-11. [PMID: 20308304 DOI: 10.1128/iai.01121-09] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Staphylococcal enterotoxin B (SEB), a shock-inducing exotoxin synthesized by Staphylococcus aureus, is an important cause of food poisoning and is a class B bioterrorism agent. SEB mediates antigen-independent activation of a major subset of the T-cell population by cross-linking T-cell receptors (TCRs) with class II major histocompatibility complex (MHC-II) molecules of antigen-presenting cells, resulting in the induction of antigen independent proliferation and cytokine secretion by a significant fraction of the T-cell population. Neutralizing antibodies inhibit SEB-mediated T-cell activation by blocking the toxin's interaction with the TCR or MHC-II and provide protection against the debilitating effects of this superantigen. We derived and searched a set of monoclonal mouse anti-SEB antibodies to identify neutralizing anti-SEB antibodies that bind to different sites on the toxin. A pair of non-cross-reactive, neutralizing anti-SEB monoclonal antibodies (MAbs) was found, and a combination of these antibodies inhibited SEB-induced T-cell proliferation in a synergistic rather than merely additive manner. In order to engineer antibodies more suitable than mouse MAbs for use in humans, the genes encoding the VL and VH gene segments of a synergistically acting pair of mouse MAbs were grafted, respectively, onto genes encoding the constant regions of human Igkappa and human IgG1, transfected into mammalian cells, and used to generate chimeric versions of these antibodies that had affinity and neutralization profiles essentially identical to their mouse counterparts. When tested in cultures of human peripheral blood mononuclear cells or splenocytes derived from HLA-DR3 transgenic mice, the chimeric human-mouse antibodies synergistically neutralized SEB-induced T-cell activation and cytokine production.
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