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Santacroce L, Topi S, Charitos IA, Lovero R, Luperto P, Palmirotta R, Jirillo E. Current Views about the Inflammatory Damage Triggered by Bacterial Superantigens and Experimental Attempts to Neutralize Superantigen-Mediated Toxic Effects with Natural and Biological Products. PATHOPHYSIOLOGY 2024; 31:18-31. [PMID: 38251046 PMCID: PMC10801599 DOI: 10.3390/pathophysiology31010002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 01/05/2024] [Accepted: 01/07/2024] [Indexed: 01/23/2024] Open
Abstract
Superantigens, i.e., staphylococcal enterotoxins and toxic shock syndrome toxin-1, interact with T cells in a different manner in comparison to conventional antigens. In fact, they activate a larger contingent of T lymphocytes, binding outside the peptide-binding groove of the major histocompatibility complex class II. Involvement of many T cells by superantigens leads to a massive release of pro-inflammatory cytokines, such as interleukin (IL)-1, IL-2, IL-6, tumor necrosis factor-alpha and interferon-gamma. Such a storm of mediators has been shown to account for tissue damage, multiorgan failure and shock. Besides conventional drugs and biotherapeutics, experiments with natural and biological products have been undertaken to attenuate the toxic effects exerted by superantigens. In this review, emphasis will be placed on polyphenols, probiotics, beta-glucans and antimicrobial peptides. In fact, these substances share a common functional denominator, since they skew the immune response toward an anti-inflammatory profile, thus mitigating the cytokine wave evoked by superantigens. However, clinical applications of these products are still scarce, and more trials are needed to validate their usefulness in humans.
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Affiliation(s)
- Luigi Santacroce
- Section of Microbiology and Virology, Interdisciplinary Department of Medicine, School of Medicine, University of Bari ‘Aldo Moro’, 70124 Bari, Italy;
| | - Skender Topi
- Department of Clinical Disciplines, University ‘Alexander Xhuvani’ of Elbasan, 3001 Elbasan, Albania
| | - Ioannis Alexandros Charitos
- Division of Pneumology and Respiratory Rehabilitation, Maugeri Clinical Scientific Research Institutes (IRCCS) of Pavia—Scientific Institute of Bari, 70124 Bari, Italy
| | - Roberto Lovero
- Clinical Pathology Unit, AOU Policlinico Consorziale di Bari-Ospedale Giovanni XXIII, 70124 Bari, Italy
| | | | - Raffaele Palmirotta
- Section of Microbiology and Virology, Interdisciplinary Department of Medicine, School of Medicine, University of Bari ‘Aldo Moro’, 70124 Bari, Italy;
| | - Emilio Jirillo
- Section of Microbiology and Virology, Interdisciplinary Department of Medicine, School of Medicine, University of Bari ‘Aldo Moro’, 70124 Bari, Italy;
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Manes A, Di Renzo T, Dodani L, Reale A, Gautiero C, Di Lauro M, Nasti G, Manco F, Muscariello E, Guida B, Tarantino G, Cataldi M. Pharmacomicrobiomics of Classical Immunosuppressant Drugs: A Systematic Review. Biomedicines 2023; 11:2562. [PMID: 37761003 PMCID: PMC10526314 DOI: 10.3390/biomedicines11092562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/13/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
The clinical response to classical immunosuppressant drugs (cIMDs) is highly variable among individuals. We performed a systematic review of published evidence supporting the hypothesis that gut microorganisms may contribute to this variability by affecting cIMD pharmacokinetics, efficacy or tolerability. The evidence that these drugs affect the composition of intestinal microbiota was also reviewed. The PubMed and Scopus databases were searched using specific keywords without limits of species (human or animal) or time from publication. One thousand and fifty five published papers were retrieved in the initial database search. After screening, 50 papers were selected to be reviewed. Potential effects on cIMD pharmacokinetics, efficacy or tolerability were observed in 17/20 papers evaluating this issue, in particular with tacrolimus, cyclosporine, mycophenolic acid and corticosteroids, whereas evidence was missing for everolimus and sirolimus. Only one of the papers investigating the effect of cIMDs on the gut microbiota reported negative results while all the others showed significant changes in the relative abundance of specific intestinal bacteria. However, no unique pattern of microbiota modification was observed across the different studies. In conclusion, the available evidence supports the hypothesis that intestinal microbiota could contribute to the variability in the response to some cIMDs, whereas data are still missing for others.
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Affiliation(s)
- Annalaura Manes
- Section of Pharmacology, Department of Neuroscience, Reproductive Sciences and Dentistry, Federico II University of Naples, 80131 Naples, Italy; (A.M.); (L.D.); (F.M.)
| | - Tiziana Di Renzo
- Institute of Food Sciences, National Research Council, 83100 Avellino, Italy; (T.D.R.); (A.R.)
| | - Loreta Dodani
- Section of Pharmacology, Department of Neuroscience, Reproductive Sciences and Dentistry, Federico II University of Naples, 80131 Naples, Italy; (A.M.); (L.D.); (F.M.)
| | - Anna Reale
- Institute of Food Sciences, National Research Council, 83100 Avellino, Italy; (T.D.R.); (A.R.)
| | - Claudia Gautiero
- Physiology Nutrition Unit, Department of Clinical Medicine and Surgery, Federico II University of Naples, 80131 Naples, Italy; (C.G.); (M.D.L.); (G.N.); (B.G.)
| | - Mariastella Di Lauro
- Physiology Nutrition Unit, Department of Clinical Medicine and Surgery, Federico II University of Naples, 80131 Naples, Italy; (C.G.); (M.D.L.); (G.N.); (B.G.)
| | - Gilda Nasti
- Physiology Nutrition Unit, Department of Clinical Medicine and Surgery, Federico II University of Naples, 80131 Naples, Italy; (C.G.); (M.D.L.); (G.N.); (B.G.)
| | - Federica Manco
- Section of Pharmacology, Department of Neuroscience, Reproductive Sciences and Dentistry, Federico II University of Naples, 80131 Naples, Italy; (A.M.); (L.D.); (F.M.)
| | - Espedita Muscariello
- Nutrition Unit, Department of Prevention, Local Health Authority Napoli 3 Sud, 80059 Naples, Italy;
| | - Bruna Guida
- Physiology Nutrition Unit, Department of Clinical Medicine and Surgery, Federico II University of Naples, 80131 Naples, Italy; (C.G.); (M.D.L.); (G.N.); (B.G.)
| | - Giovanni Tarantino
- Department of Clinical Medicine and Surgery, Federico II University of Naples, 80131 Naples, Italy;
| | - Mauro Cataldi
- Section of Pharmacology, Department of Neuroscience, Reproductive Sciences and Dentistry, Federico II University of Naples, 80131 Naples, Italy; (A.M.); (L.D.); (F.M.)
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Camp J, Glaubitz L, Filla T, Kaasch AJ, Fuchs F, Scarborough M, Kim HB, Tilley R, Liao CH, Edgeworth J, Nsutebu E, López-Cortés LE, Morata L, Llewelyn M, Fowler VG, Thwaites G, Seifert H, Kern WV, Kuss O, Rieg S. Impact of Immunosuppressive Agents on Clinical Manifestations and Outcome of Staphylococcus aureus Bloodstream Infection: A Propensity Score-Matched Analysis in 2 Large, Prospectively Evaluated Cohorts. Clin Infect Dis 2021; 73:1239-1247. [PMID: 33914861 DOI: 10.1093/cid/ciab385] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Staphylococcus aureus bloodstream infection (SAB) is a common, life-threatening infection. The impact of immunosuppressive agents on the outcome of patients with SAB is incompletely understood. METHODS Data from 2 large prospective, international, multicenter cohort studies (Invasive Staphylococcus aureus Infections Cohort [INSTINCT] and International Staphylococcus aureus Collaboration [ISAC]) between 2006 and 2015 were analyzed. Patients receiving immunosuppressive agents were identified and a 1:1 propensity score-matched analysis was performed to adjust for baseline characteristics of patients. Overall survival and time to SAB-related late complications (SAB relapse, infective endocarditis, osteomyelitis, or other deep-seated manifestations) were analyzed by Cox regression and competing risk analyses, respectively. This approach was then repeated for specific immunosuppressive agents (corticosteroid monotherapy and immunosuppressive agents other than steroids [IMOTS]). RESULTS Of 3188 analyzed patients, 309 were receiving immunosuppressive treatment according to our definitions and were matched to 309 nonimmunosuppressed patients. After propensity score matching, baseline characteristics were well balanced. In the Cox regression analysis, we observed no significant difference in survival between the 2 groups (death during follow-up: 105/309 [33.9%] immunosuppressed vs 94/309 [30.4%] nonimmunosuppressed; hazard ratio [HR], 1.20 [95% confidence interval {CI}, .84-1.71]). Competing risk analysis showed a cause-specific HR of 1.81 (95% CI, .85-3.87) for SAB-related late complications in patients receiving immunosuppressive agents. The cause-specific HR was higher in patients taking IMOTS (3.69 [95% CI, 1.41-9.68]). CONCLUSIONS Immunosuppressive agents were not associated with an overall higher mortality. The risk for SAB-related late complications in patients receiving specific immunosuppressive agents such as IMOTS warrants further investigations.
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Affiliation(s)
- Johannes Camp
- Division of Infectious Diseases, Department of Medicine II, Medical Centre - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Lina Glaubitz
- Institute for Occupational, Social and Environmental Medicine, Center for Health and Society, Faculty of Medicine, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Tim Filla
- Institute of Medical Biometry and Bioinformatics, Faculty of Medicine, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Achim J Kaasch
- Institute of Medical Microbiology and Hospital Hygiene, University Hospital, Faculty of Medicine, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Frieder Fuchs
- Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Medical Faculty and University Hospital of Cologne, Cologne, Germany
| | - Matt Scarborough
- Nuffield Department of Medicine, Oxford University Hospitals NHS Foundation, Oxford, United Kingdom
| | - Hong Bin Kim
- Division of Infectious Diseases, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Robert Tilley
- Department of Microbiology, University Hospitals Plymouth NHS Trust, Plymouth, United Kingdom
| | - Chun-Hsing Liao
- Infectious Diseases, Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Jonathan Edgeworth
- Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, King's College London NHS Foundation Trust and Guy's and St Thomas' Hospitals NHS Foundation Trust, London, United Kingdom
| | - Emmanuel Nsutebu
- Tropical and Infectious Disease Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom
| | - Luis Eduardo López-Cortés
- Infectious Diseases and Clinical Microbiology Unit, Hospital Universitario Virgen Macarena, Department of Medicine, University of Seville, Seville, Spain
| | - Laura Morata
- Service of Infectious Diseases, Hospital Clinic of Barcelona, Barcelona, Spain
| | - Martin Llewelyn
- Department of Infectious Diseases and Microbiology, Brighton and Sussex University Hospitals NHS Trust, Brighton, United Kingdom
| | - Vance G Fowler
- Division of Infectious Diseases and International Health, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Guy Thwaites
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Harald Seifert
- Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Medical Faculty and University Hospital of Cologne, Cologne, Germany
| | - Winfried V Kern
- Division of Infectious Diseases, Department of Medicine II, Medical Centre - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Oliver Kuss
- German Diabetes Center, Leibniz Institute for Diabetes Research at Heinrich-Heine-University Düsseldorf, Institute for Biometrics and Epidemiology, Düsseldorf, Germany
| | - Siegbert Rieg
- Division of Infectious Diseases, Department of Medicine II, Medical Centre - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Muire PJ, Mangum LH, Wenke JC. Time Course of Immune Response and Immunomodulation During Normal and Delayed Healing of Musculoskeletal Wounds. Front Immunol 2020; 11:1056. [PMID: 32582170 PMCID: PMC7287024 DOI: 10.3389/fimmu.2020.01056] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/01/2020] [Indexed: 12/20/2022] Open
Abstract
Single trauma injuries or isolated fractures are often manageable and generally heal without complications. In contrast, high-energy trauma results in multi/poly-trauma injury patterns presenting imbalanced pro- and anti- inflammatory responses often leading to immune dysfunction. These injuries often exhibit delayed healing, leading to fibrosis of injury sites and delayed healing of fractures depending on the intensity of the compounding traumas. Immune dysfunction is accompanied by a temporal shift in the innate and adaptive immune cells distribution, triggered by the overwhelming release of an arsenal of inflammatory mediators such as complements, cytokines and damage associated molecular patterns (DAMPs) from necrotic cells. Recent studies have implicated this dysregulated inflammation in the poor prognosis of polytraumatic injuries, however, interventions focusing on immunomodulating inflammatory cellular composition and activation, if administered incorrectly, can result in immune suppression and unintended outcomes. Immunomodulation therapy is promising but should be conducted with consideration for the spatial and temporal distribution of the immune cells during impaired healing. This review describes the current state of knowledge in the spatiotemporal distribution patterns of immune cells at various stages during musculoskeletal wound healing, with a focus on recent advances in the field of Osteoimmunology, a study of the interface between the immune and skeletal systems, in long bone fractures. The goals of this review are to (1) discuss wound and fracture healing processes of normal and delayed healing in skeletal muscles and long bones; (2) provide a balanced perspective on temporal distributions of immune cells and skeletal cells during healing; and (3) highlight recent therapeutic interventions used to improve fracture healing. This review is intended to promote an understanding of the importance of inflammation during normal and delayed wound and fracture healing. Knowledge gained will be instrumental in developing novel immunomodulatory approaches for impaired healing.
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Affiliation(s)
- Preeti J Muire
- Orthopaedic Trauma Research Department, US Army Institute of Surgical Research, Fort Sam Houston, TX, United States
| | - Lauren H Mangum
- Orthopaedic Trauma Research Department, US Army Institute of Surgical Research, Fort Sam Houston, TX, United States
| | - Joseph C Wenke
- Orthopaedic Trauma Research Department, US Army Institute of Surgical Research, Fort Sam Houston, TX, United States
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Javanshir Khoei A, Forsatkar MN, Brown C. Behavioral and immunotoxic effects of Prograf® (tacrolimus) in the male Siamese fighting fish. ECOTOXICOLOGY (LONDON, ENGLAND) 2019; 28:1032-1037. [PMID: 31489591 DOI: 10.1007/s10646-019-02103-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/21/2019] [Indexed: 06/10/2023]
Abstract
Siamese fighting fish (Betta splendens) has been extensively exploited in the behavioral and physiological toxicology studies of drugs. Tacrolimus is an immunosuppressant drug largely used in liver and renal transplantations. Here we found that a 7-day exposure of male B. splendens to concentrations of 0.05 and 0.1 µg/mL Prograf® (tacrolimus) caused alterations in aggression and immunity indexes. Tacrolimus exposed fish presented lower opercular display in a mirror test which is indicative of reduced aggression. In addition, serum levels of lysozyme, IgM, alternative complement, and bactericidal activity of subjects exposed to 0.1 µg/mL tacrolimus were lower than those from the control treatment. These results showed the behavioral impairment and immunotoxic impacts of tacrolimus in a model of aquatic toxicology. The results suggest fishes provide a possible model for better understanding of the drug action in vertebrates, and possible consequences for the environment via its effects on non-target organisms in an ecotoxicology context.
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Affiliation(s)
- Arash Javanshir Khoei
- Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran
| | | | - Culum Brown
- Department of Biological Sciences, Macquarie University, Eastern Road, Sydney, NSW, 2109, Australia
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Staphylococcal Superantigens: Pyrogenic Toxins Induce Toxic Shock. Toxins (Basel) 2019; 11:toxins11030178. [PMID: 30909619 PMCID: PMC6468478 DOI: 10.3390/toxins11030178] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/18/2019] [Accepted: 03/20/2019] [Indexed: 01/01/2023] Open
Abstract
Staphylococcal enterotoxin B (SEB) and related superantigenic toxins produced by Staphylococcus aureus are potent activators of the immune system. These protein toxins bind to major histocompatibility complex (MHC) class II molecules and specific Vβ regions of T-cell receptors (TCRs), resulting in the activation of both monocytes/macrophages and T lymphocytes. The bridging of TCRs with MHC class II molecules by superantigens triggers an early “cytokine storm” and massive polyclonal T-cell proliferation. Proinflammatory cytokines, tumor necrosis factor α, interleukin 1 (IL-1), IL-2, interferon γ (IFNγ), and macrophage chemoattractant protein 1 elicit fever, inflammation, multiple organ injury, hypotension, and lethal shock. Upon MHC/TCR ligation, superantigens induce signaling pathways, including mitogen-activated protein kinase cascades and cytokine receptor signaling, which results in NFκB activation and the phosphoinositide 3-kinase/mammalian target of rapamycin pathways. In addition, gene profiling studies have revealed the essential roles of innate antimicrobial defense genes in the pathogenesis of SEB. The genes expressed in a murine model of SEB-induced shock include intracellular DNA/RNA sensors, apoptosis/DNA damage-related molecules, endoplasmic reticulum/mitochondrial stress responses, immunoproteasome components, and IFN-stimulated genes. This review focuses on the signaling pathways induced by superantigens that lead to the activation of inflammation and damage response genes. The induction of these damage response genes provides evidence that SEB induces danger signals in host cells, resulting in multiorgan injury and toxic shock. Therapeutics targeting both host inflammatory and cell death pathways can potentially mitigate the toxic effects of staphylococcal superantigens.
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Xu YP, Sui XL, Zhang AS, Ye L, Gu FJ, Chen JH. Monocytes, endoplasmic reticulum stress and metabolomics in dogs with multiple organ dysfunction syndrome treated by continuous venovenous hemodiafiltration. Oncotarget 2018; 8:34992-35008. [PMID: 28380442 PMCID: PMC5471029 DOI: 10.18632/oncotarget.16533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 03/01/2017] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVES We tried to investigate the mechanism of continuous venovenous hemodiafiltration (CVVHDF) treatment in monocytes function, endoplasmic reticulum (ER) stress signaling pathways, metabolomics and histopathological changes of MODS dogs, and aimed to enhance the understanding of pathogenesis and provide novel avenues to potential therapies. METHODS 12 male Beagle dogs were used to develop the stable models of MODS by using hemorrhagic shock plus resuscitation and endotoxemia, and assigned randomly to CVVHDF group (n=6) and MODS group (n=6). The dogs in CVVHDF group were given the typical CVVHDF treatment for 24h after the completion of endotoxin intravenous infusion, while those in MODS group were offered the i.v heparin instead only. Serum sample were collected at five time points, i.e. before anesthesia, 0h, 6h, 12h and 24h after the endotoxin injection (T1~T5, respectively), and meanwhile, the changes of mRNA, protein and human umbilical vein endothelial cells (HUVECs) apoptosis rates in JNK, CHOP and Caspase-12 were observed before and after interfered by RNA interference technology. RESULTS The levels of DLA-DR, IL-1β and IL-4 were higher than those in MODS group after the CVVHDF treatment, and the early and late apoptosis rates showed downward trend compared with MODS group. In vitro and prior to RNA interference (RNAi), the levels of mRNA and protein expression and HUVECs apoptosis rates of JNK, CHOP and Caspase-12 in CVVHDF group were significantly lower compared to T1 and MODS group respectively. However, the levels of mRNA and protein expression and HUVECs apoptosis rates were significantly lower than those before interfered by RNAi in both two groups. The serum levels of LPCs, ornithine, proline, methionine, etc. were down-regulated while carnitines, FFAs, PC, etc. were increased significantly in MODS (T4), and the serum levels of methionine, proline, arginine and lysine were increased while carnitine, LPCs, PCs, SMs and orthophosporic acid were decreased after 12 hours CVVHDF treatment (T4). CONCLUSION CVVHDF treatment could reduce the apoptosis of the cells by enhancing the antigen presentation, improving the anti-inflammatory and proinflammatory imbalance and even correcting the metabolic disorder of amino acids and phospholipids.
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Affiliation(s)
- Yun-Peng Xu
- Department of Nephropathy, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region of China, China
| | - Xiao-Lu Sui
- Department of Nephropathy, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region of China, China
| | - Ai-Sha Zhang
- Department of Nephropathy, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region of China, China
| | - Lei Ye
- Department of Nephropathy, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region of China, China
| | - Feng-Juan Gu
- Department of Nephropathy, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region of China, China
| | - Ji-Hong Chen
- Department of Nephropathy, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region of China, China
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Karau MJ, Tilahun ME, Krogman A, Osborne BA, Goldsby RA, David CS, Mandrekar JN, Patel R, Rajagopalan G. Passive therapy with humanized anti-staphylococcal enterotoxin B antibodies attenuates systemic inflammatory response and protects from lethal pneumonia caused by staphylococcal enterotoxin B-producing Staphylococcus aureus. Virulence 2017; 8:1148-1159. [PMID: 27925510 PMCID: PMC5711449 DOI: 10.1080/21505594.2016.1267894] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 11/21/2016] [Accepted: 11/28/2016] [Indexed: 02/08/2023] Open
Abstract
Drugs such as linezolid that inhibit bacterial protein synthesis may be beneficial in treating infections caused by toxigenic Staphylococcus aureus. As protein synthesis inhibitors have no effect on preformed toxins, neutralization of pathogenic exotoxins with anti-toxin antibodies may be beneficial in conjunction with antibacterial therapy. Herein, we evaluated the efficacy of human-mouse chimeric high-affinity neutralizing anti-staphylococcal enterotoxin B (SEB) antibodies in the treatment of experimental pneumonia caused by SEB-producing S. aureus. Since HLA class II transgenic mice mount a stronger systemic immune response following challenge with SEB and are more susceptible to SEB-induced lethal toxic shock than conventional mice strains, HLA-DR3 transgenic mice were used. Lethal pneumonia caused by SEB-producing S. aureus in HLA-DR3 transgenic mice was characterized by robust T cell activation and elevated systemic levels of several pro-inflammatory cytokines and chemokines. Prophylactic administration of a single dose of linezolid 30 min prior to the onset of infection attenuated the systemic inflammatory response and protected from mortality whereas linezolid administered 60 min after the onset of infection failed to confer significant protection. Human-mouse chimeric high-affinity neutralizing anti-SEB antibodies alone, but not polyclonal human IgG, mitigated this response and protected from death when administered immediately after initiation of infection. Further, anti-SEB antibodies as well as intact polyclonal human IgG, but not its Fab or Fc fragments, protected from lethal pneumonia when followed with linezolid therapy 60 min later. In conclusion, neutralization of superantigens with high-affinity antibodies may have beneficial effects in pneumonia.
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Affiliation(s)
- Melissa J. Karau
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Mulualem E. Tilahun
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, USA
- Department of Biology, Amherst College, Amherst, MA, USA
| | - Ashton Krogman
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Barbara A. Osborne
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, USA
| | | | - Chella S. David
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Jayawant N. Mandrekar
- Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Robin Patel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
- Division of Infectious Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Govindarajan Rajagopalan
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
- Division of Infectious Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA
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Krakauer T. FDA-approved immunosuppressants targeting staphylococcal superantigens: mechanisms and insights. Immunotargets Ther 2017; 6:17-29. [PMID: 28497030 PMCID: PMC5423536 DOI: 10.2147/itt.s125429] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Immunostimulating staphylococcal enterotoxin B (SEB) and related superantigenic toxins cause diseases in human beings and laboratory animals by hyperactivating cells of the immune system. These protein toxins bind to the major histocompatibility complex class II (MHC II) molecules and specific Vβ regions of T-cell receptors (TCRs), resulting in the stimulation of both monocytes/macrophages and T lymphocytes. The bridging of TCR with MHC II molecules by superantigens triggers intracellular signaling cascades, resulting in excessive release of proinflammatory mediators and massive polyclonal T-cell proliferation. The early induction of tumor necrosis factor α, interleukin 1 (IL-1), interleukin 2 (IL-2), interferon gamma (IFNγ), and macrophage chemoattractant protein 1 promotes fever, inflammation, and multiple organ injury. The signal transduction pathways for staphylococcal superantigen-induced toxicity downstream from TCR/major histocompatibility complex (MHC) ligation and interaction of cell surface co-stimulatory molecules include the mitogen-activated protein kinase cascades and cytokine receptor signaling, activating nuclear factor κB (NFκB) and the phosphoinositide 3-kinase/mammalian target of rapamycin pathways. Knowledge of host regulation within these activated pathways and molecules initiated by SEB and other superantigens enables the selection of US Food and Drug Administration (FDA)-approved drugs to interrupt and prevent superantigen-induced shock in animal models. This review focuses on the use of FDA-approved immunosuppressants in targeting the signaling pathways induced by staphylococcal superantigens.
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Affiliation(s)
- Teresa Krakauer
- Department of Immunology, Molecular Translational Sciences Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD, USA
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10
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Krakauer T, Pradhan K, Stiles BG. Staphylococcal Superantigens Spark Host-Mediated Danger Signals. Front Immunol 2016; 7:23. [PMID: 26870039 PMCID: PMC4735405 DOI: 10.3389/fimmu.2016.00023] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 01/18/2016] [Indexed: 12/19/2022] Open
Abstract
Staphylococcal enterotoxin B (SEB) of Staphylococcus aureus, and related superantigenic toxins produced by myriad microbes, are potent stimulators of the immune system causing a variety of human diseases from transient food poisoning to lethal toxic shock. These protein toxins bind directly to specific Vβ regions of T-cell receptors (TCR) and major histocompatibility complex (MHC) class II on antigen-presenting cells, resulting in hyperactivation of T lymphocytes and monocytes/macrophages. Activated host cells produce excessive amounts of proinflammatory cytokines and chemokines, especially tumor necrosis factor α, interleukin 1 (IL-1), IL-2, interferon γ (IFNγ), and macrophage chemoattractant protein 1 causing clinical symptoms of fever, hypotension, and shock. Because of superantigen-induced T cells skewed toward TH1 helper cells, and the induction of proinflammatory cytokines, superantigens can exacerbate autoimmune diseases. Upon TCR/MHC ligation, pathways induced by superantigens include the mitogen-activated protein kinase cascades and cytokine receptor signaling, resulting in activation of NFκB and the phosphoinositide 3-kinase/mammalian target of rapamycin pathways. Various mouse models exist to study SEB-induced shock including those with potentiating agents, transgenic mice and an “SEB-only” model. However, therapeutics to treat toxic shock remain elusive as host response genes central to pathogenesis of superantigens have only been identified recently. Gene profiling of a murine model for SEB-induced shock reveals novel molecules upregulated in multiple organs not previously associated with SEB-induced responses. The pivotal genes include intracellular DNA/RNA sensors, apoptosis/DNA damage-related molecules, immunoproteasome components, as well as antiviral and IFN-stimulated genes. The host-wide induction of these, and other, antimicrobial defense genes provide evidence that SEB elicits danger signals resulting in multi-organ damage and toxic shock. Ultimately, these discoveries might lead to novel therapeutics for various superantigen-based diseases.
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Affiliation(s)
- Teresa Krakauer
- Department of Immunology, Molecular Translational Sciences Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick , Frederick, MD , USA
| | - Kisha Pradhan
- Biology Department, Wilson College , Chambersburg, PA , USA
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11
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Song SS, Matiz C, Tom WL, Calame A, Krakowski AC, Friedlander SF. Ecthyma Gangrenosum-Like Lesions Secondary to Methicillin-Sensitive Staphylococcus aureus in an Immunocompetent Child. Pediatr Dermatol 2015; 32:e259-62. [PMID: 26459977 DOI: 10.1111/pde.12699] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
We describe a previously healthy 15-month-old girl who developed ecthyma gangrenosum (EG)-like lesions secondary to methicillin-sensitive Staphylococcus aureus (MSSA). Her systemic symptoms and negative blood cultures suggested MSSA toxin-mediated effects. When toxin-mediated systemic symptoms accompany such lesions, pathogens other than Pseudomonas aeruginosa should be considered.
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Affiliation(s)
- Silvia S Song
- Department of Dermatology, University of California at San Diego, San Diego, California.,Department of Dermatology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Catalina Matiz
- Department of Dermatology, University of California at San Diego, San Diego, California.,Rady Children's Hospital, San Diego, California
| | - Wynnis L Tom
- Department of Dermatology, University of California at San Diego, San Diego, California.,Rady Children's Hospital, San Diego, California
| | - Antoanella Calame
- Rady Children's Hospital, San Diego, California.,Compass Dermatopathology, La Jolla, California
| | - Andrew C Krakowski
- Department of Dermatology, University of California at San Diego, San Diego, California.,Rady Children's Hospital, San Diego, California
| | - Sheila F Friedlander
- Department of Dermatology, University of California at San Diego, San Diego, California.,Rady Children's Hospital, San Diego, California
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12
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Chung JW, Greenwood-Quaintance KE, Karau MJ, Tilahun A, Khaleghi SR, Chowdhary VR, David CS, Patel R, Rajagopalan G. Superantigens produced by catheter-associated Staphylococcus aureus elicit systemic inflammatory disease in the absence of bacteremia. J Leukoc Biol 2015; 98:271-81. [PMID: 25979434 DOI: 10.1189/jlb.4a1214-577rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 04/17/2015] [Indexed: 11/24/2022] Open
Abstract
SAgs, produced by Staphylococcus aureus, play a major role in the pathogenesis of invasive staphylococcal diseases by inducing potent activation of the immune system. However, the role of SAgs, produced by S. aureus, associated with indwelling devices or tissues, are not known. Given the prevalence of device-associated infection with toxigenic S. aureus in clinical settings and the potency of SAgs, we hypothesized that continuous exposure to SAgs produced by catheter-associated S. aureus could have systemic consequences. To investigate these effects, we established a murine in vivo catheter colonization model. One centimeter long intravenous catheters were colonized with a clinical S. aureus isolate producing SAgs or isogenic S. aureus strains, capable or incapable of producing SAg. Catheters were subcutaneously implanted in age-matched HLA-DR3, B6, and AE(o) mice lacking MHC class II molecules and euthanized 7 d later. There was no evidence of systemic infection. However, in HLA-DR3 transgenic mice, which respond robustly to SSAgs, the SSAg-producing, but not the nonproducing strains, caused a transient increase in serum cytokine levels and a protracted expansion of splenic CD4(+) T cells expressing SSAg-reactive TCR Vβ8. Lungs, livers, and kidneys from these mice showed infiltration with CD4(+) and CD11b(+) cells. These findings were absent in B6 and AE(o) mice, which are known to respond poorly to SSAgs. Overall, our novel findings suggest that systemic immune activation elicited by SAgs, produced by S. aureus colonizing foreign bodies, could have clinical consequences in humans.
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Affiliation(s)
- Jin-Won Chung
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Kerryl E Greenwood-Quaintance
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Melissa J Karau
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Ashenafi Tilahun
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Shahryar Rostamkolaei Khaleghi
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Vaidehi R Chowdhary
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Chella S David
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Robin Patel
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Govindarajan Rajagopalan
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
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13
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The impact of Staphylococcus aureus-associated molecular patterns on staphylococcal superantigen-induced toxic shock syndrome and pneumonia. Mediators Inflamm 2014; 2014:468285. [PMID: 25024509 PMCID: PMC4082930 DOI: 10.1155/2014/468285] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/25/2014] [Accepted: 03/29/2014] [Indexed: 11/25/2022] Open
Abstract
Staphylococcus aureus is capable of causing a spectrum of human illnesses. During serious S. aureus infections, the staphylococcal pathogen-associated molecular patterns (PAMPs) such as peptidoglycan, lipoteichoic acid, and lipoproteins and even intact S. aureus, are believed to act in conjunction with the staphylococcal superantigens (SSAg) to activate the innate and adaptive immune system, respectively, and cause immunopathology. However, recent studies have shown that staphylococcal PAMPs could suppress inflammation by several mechanisms and protect from staphylococcal toxic shock syndrome, a life-threatening systemic disease caused by toxigenic S. aureus. Given the contradictory pro- and anti-inflammatory roles of staphylococcal PAMPs, we examined the effects of S. aureus-derived molecular patterns on immune responses driven by SSAg in vivo using HLA-DR3 and HLA-DQ8 transgenic mice. Our study showed that neither S. aureus-derived peptidoglycans (PGN), lipoteichoic acid (LTA), nor heat-killed Staphylococcus aureus (HKSA) inhibited SSAg-induced T cell proliferation in vitro. They failed to antagonize the immunostimulatory effects of SSAg in vivo as determined by their inability to attenuate systemic cytokine/chemokine response and reduce SSAg-induced T cell expansion. These staphylococcal PAMPs also failed to protect HLA-DR3 as well as HLA-DQ8 transgenic mice from either SSAg-induced toxic shock or pneumonia induced by a SSAg-producing strain of S. aureus.
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Chung JW, Karau MJ, Greenwood-Quaintance KE, Ballard AD, Tilahun A, Khaleghi SR, David CS, Patel R, Rajagopalan G. Superantigen profiling of Staphylococcus aureus infective endocarditis isolates. Diagn Microbiol Infect Dis 2014; 79:119-24. [PMID: 24745820 DOI: 10.1016/j.diagmicrobio.2014.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 03/05/2014] [Accepted: 03/09/2014] [Indexed: 12/20/2022]
Abstract
The frequency of superantigen production among Staphylococcus aureus isolates associated with endocarditis is not well defined. We tested 154 S. aureus isolates from definite infective endocarditis cases for the presence of staphylococcal enterotoxins A-E, H, and TSST-1 by PCR, enzyme-linked immunosorbent assay, and using an HLA-DR3 transgenic mouse splenocyte proliferation assay. Sixty-three isolates (50.8%) tested positive for at least 1 superantigen gene, with 21 (16.9%) testing positive for more than 2. tst (28.6%) was most common, followed by seb (27%), sea (22.2%), sed (20.6%), see (17.5%), and sec (11.1%). Of 41 methicillin-resistant S. aureus, 21 had superantigen genes, with sed being more frequently detected in this group compared to methicillin-susceptible S. aureus (P < 0.05). Superantigen genes were not associated with mortality (P = 0.81). 75% of PCR-positive isolates induced robust splenocyte proliferation. Overall, more than half of S. aureus isolates causing endocarditis carry superantigen genes, of which most are functional.
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Affiliation(s)
- Jin-Won Chung
- Divisions of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA; Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Melissa J Karau
- Divisions of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Kerryl E Greenwood-Quaintance
- Divisions of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Alessandro D Ballard
- Divisions of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Ashenafi Tilahun
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | | | - Chella S David
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Robin Patel
- Divisions of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA; Division of Infectious Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Govindarajan Rajagopalan
- Division of Infectious Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA; Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA.
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Sharma P, Wang N, Kranz DM. Soluble T cell receptor Vβ domains engineered for high-affinity binding to staphylococcal or streptococcal superantigens. Toxins (Basel) 2014; 6:556-74. [PMID: 24476714 PMCID: PMC3942751 DOI: 10.3390/toxins6020556] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/21/2014] [Accepted: 01/22/2014] [Indexed: 11/29/2022] Open
Abstract
Staphylococcus aureus and group A Streptococcus secrete a collection of toxins called superantigens (SAgs), so-called because they stimulate a large fraction of an individual’s T cells. One consequence of this hyperactivity is massive cytokine release leading to severe tissue inflammation and, in some cases, systemic organ failure and death. The molecular basis of action involves the binding of the SAg to both a T cell receptor (TCR) on a T cell and a class II product of the major histocompatibility complex (MHC) on an antigen presenting cell. This cross-linking leads to aggregation of the TCR complex and signaling. A common feature of SAgs is that they bind with relatively low affinity to the variable region (V) of the beta chain of the TCR. Despite this low affinity binding, SAgs are very potent, as each T cell requires only a small fraction of their receptors to be bound in order to trigger cytokine release. To develop high-affinity agents that could neutralize the activity of SAgs, and facilitate the development of detection assays, soluble forms of the Vβ regions have been engineered to affinities that are up to 3 million-fold higher for the SAg. Over the past decade, six different Vβ regions against SAgs from S. aureus (SEA, SEB, SEC3, TSST-1) or S. pyogenes (SpeA and SpeC) have been engineered for high-affinity using yeast display and directed evolution. Here we review the engineering of these high-affinity Vβ proteins, structural features of the six different SAgs and the Vβ proteins, and the specific properties of the engineered Vβ regions that confer high-affinity and specificity for their SAg ligands.
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Affiliation(s)
- Preeti Sharma
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA.
| | - Ningyan Wang
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA.
| | - David M Kranz
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA.
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Krakauer T. Update on staphylococcal superantigen-induced signaling pathways and therapeutic interventions. Toxins (Basel) 2013; 5:1629-54. [PMID: 24064719 PMCID: PMC3798877 DOI: 10.3390/toxins5091629] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 09/13/2013] [Accepted: 09/13/2013] [Indexed: 12/20/2022] Open
Abstract
Staphylococcal enterotoxin B (SEB) and related bacterial toxins cause diseases in humans and laboratory animals ranging from food poisoning, acute lung injury to toxic shock. These superantigens bind directly to the major histocompatibility complex class II molecules on antigen-presenting cells and specific Vβ regions of T-cell receptors (TCR), resulting in rapid hyper-activation of the host immune system. In addition to TCR and co-stimulatory signals, proinflammatory mediators activate signaling pathways culminating in cell-stress response, activation of NFκB and mammalian target of rapamycin (mTOR). This article presents a concise review of superantigen-activated signaling pathways and focuses on the therapeutic challenges against bacterial superantigens.
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Affiliation(s)
- Teresa Krakauer
- Department of Immunology, Integrated Toxicology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702 5011, USA.
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Krakauer T. PI3K/Akt/mTOR, a pathway less recognized for staphylococcal superantigen-induced toxicity. Toxins (Basel) 2012; 4:1343-66. [PMID: 23202320 PMCID: PMC3509712 DOI: 10.3390/toxins4111343] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 11/12/2012] [Accepted: 11/13/2012] [Indexed: 12/27/2022] Open
Abstract
Immunostimulating staphylococcal enterotoxin B (SEB) and related superantigenic toxins cause diseases in humans and laboratory animals by activating cells of the immune system. These toxins bind directly to the major histocompatibility complex (MHC) class II molecules on antigen-presenting cells and specific Vβ regions of T-cell receptors (TCR), resulting in hyperactivation of both T lymphocytes and monocytes/macrophages. Activated host cells produce excessive amounts of proinflammatory cytokines and chemokines, especially tumor necrosis factor α, interleukin 1 (IL-1), IL-2, interferon γ (IFNγ), and macrophage chemoattractant protein 1 causing clinical symptoms of fever, hypotension, and shock. The well-explored signal transduction pathways for SEB-induced toxicity downstream from TCR/MHC ligation and interaction of cell surface co-stimulatory molecules include the mitogen-activated protein kinase cascades and cytokine receptor signaling, culminating in NFκB activation. Independently, IL-2, IFNγ, and chemokines from activated T cells signal via the phosphoinositide 3-kinase (PI3K), the serine/threonine kinases, Akt and mammalian target of rapamycin (mTOR) pathways. This article reviews the signaling molecules induced by superantigens in the activation of PI3K/Akt/mTOR pathways leading to staphylococcal superantigen-induced toxicity and updates potential therapeutics against superantigens.
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Affiliation(s)
- Teresa Krakauer
- Department of Immunology, Integrated Toxicology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702, USA.
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Linezolid is superior to vancomycin in experimental pneumonia caused by Superantigen-Producing staphylococcus aureus in HLA class II transgenic mice. Antimicrob Agents Chemother 2012; 56:5401-5. [PMID: 22850509 DOI: 10.1128/aac.01080-12] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Superantigens (SAg), the potent activators of the immune system, are important determinants of Staphylococcus aureus virulence and pathogenicity. Superior response to SAg in human leukocyte antigen (HLA)-DR3 transgenic mice rendered them more susceptible than C57BL/6 mice to pneumonia caused by SAg-producing strains of S. aureus. Linezolid, a bacterial protein synthesis inhibitor, was superior to vancomycin in inhibiting SAg production by S. aureus in vitro and conferred greater protection from pneumonia caused by SAg-producing staphylococci.
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