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Tuffs SW, Dufresne K, Rishi A, Walton NR, McCormick JK. Novel insights into the immune response to bacterial T cell superantigens. Nat Rev Immunol 2024:10.1038/s41577-023-00979-2. [PMID: 38225276 DOI: 10.1038/s41577-023-00979-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2023] [Indexed: 01/17/2024]
Abstract
Bacterial T cell superantigens (SAgs) are a family of microbial exotoxins that function to activate large numbers of T cells simultaneously. SAgs activate T cells by direct binding and crosslinking of the lateral regions of MHC class II molecules on antigen-presenting cells with T cell receptors (TCRs) on T cells; these interactions alter the normal TCR-peptide-MHC class II architecture to activate T cells in a manner that is independent of the antigen specificity of the TCR. SAgs have well-recognized, central roles in human diseases such as toxic shock syndrome and scarlet fever through their quantitative effects on the T cell response; in addition, numerous other consequences of SAg-driven T cell activation are now being recognized, including direct roles in the pathogenesis of endocarditis, bloodstream infections, skin disease and pharyngitis. In this Review, we summarize the expanding family of bacterial SAgs and how these toxins can engage highly diverse adaptive immune receptors. We highlight recent findings regarding how SAg-driven manipulation of the adaptive immune response may operate in multiple human diseases, as well as contributing to the biology and life cycle of SAg-producing bacterial pathogens.
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Affiliation(s)
- Stephen W Tuffs
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Karine Dufresne
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Aanchal Rishi
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Nicholas R Walton
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - John K McCormick
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada.
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Sun Y, Hu B, Stanley G, Harris ZM, Gautam S, Homer R, Koff JL, Rajagopalan G. IFN- γ Is Protective in Cytokine Release Syndrome-associated Extrapulmonary Acute Lung Injury. Am J Respir Cell Mol Biol 2023; 68:75-89. [PMID: 36125351 PMCID: PMC9817908 DOI: 10.1165/rcmb.2022-0117oc] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 09/19/2022] [Indexed: 02/05/2023] Open
Abstract
The mechanisms by which excessive systemic activation of adaptive T lymphocytes, as in cytokine release syndrome (CRS), leads to innate immune cell-mediated acute lung injury (ALI) or acute respiratory distress syndrome, often in the absence of any infection, remains unknown. Here, we investigated the roles of IFN-γ and IL-17A, key T-cell cytokines significantly elevated in patients with CRS, in the immunopathogenesis of CRS-induced extrapulmonary ALI. CRS was induced in wild-type (WT), IL-17A- and IFN-γ knockout (KO) human leukocyte antigen-DR3 transgenic mice with 10 μg of the superantigen, staphylococcal enterotoxin B, given intraperitoneally. Several ALI parameters, including gene expression profiling in the lungs, were studied 4, 24, or 48 hours later. Systemic T-cell activation with staphylococcal enterotoxin B resulted in robust upregulation of several chemokines, S100A8/A9, matrix metalloproteases, and other molecules implicated in tissue damage, granulocyte as well as agranulocyte adhesion, and diapedesis in the lungs as early as 4 hours, which was accompanied by subsequent neutrophil/eosinophil lung infiltration and severe ALI in IFN-γ KO mice. These pathways were significantly underexpressed in IL-17A KO mice, which manifested mildest ALI and intermediate in WT mice. Neutralization of IFN-γ worsened ALI in WT and IL-17A KO mice, whereas neutralizing IL-17A did not mitigate lung injury in IFN-γ KO mice, suggesting a dominant protective role for IFN-γ in ALI and that IL-17A is dispensable. Ruxolitinib, a Janus kinase inhibitor, increased ALI severity in WT mice. Thus, our study identified novel mechanisms of ALI in CRS and its differential modulation by IFN-γ and IL-17A.
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Affiliation(s)
- Ying Sun
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, and
| | - Buqu Hu
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, and
| | - Gail Stanley
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, and
| | - Zachary M. Harris
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, and
| | - Samir Gautam
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, and
| | - Robert Homer
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, and
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut; and
- Pathology and Laboratory Medicine Service, Veterans Affairs Connecticut HealthCare System, West Haven, Connecticut
| | - Jonathan L. Koff
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, and
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Larcombe S, Jiang JH, Hutton ML, Abud HE, Peleg AY, Lyras D. A mouse model of Staphylococcus aureus small intestinal infection. J Med Microbiol 2020; 69:290-297. [PMID: 32004137 PMCID: PMC7431102 DOI: 10.1099/jmm.0.001163] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Introduction Staphylococcus aureus is a recognised cause of foodborne intoxication and antibiotic-associated diarrhoea (AAD), which are both mediated by staphylococcal enterotoxins. However, unlike foodborne intoxication, AAD appears to require infection of the host. While S. aureus intoxication is widely studied, little is known about S. aureus pathogenesis in the context of gastrointestinal infection. Aim To develop a mouse model of S. aureus gastrointestinal infection. Methodology An established AAD mouse model was adapted for S. aureus infection, and damage observed via histopathological analysis and immunostaining of intestinal tissues. Results Various strains colonised the mouse model, and analysis showed that although clinical signs of disease were not seen, S. aureus infection induced damage in the small intestine, disrupting host structures essential for epithelial integrity. Studies using a staphylococcal enterotoxin B mutant showed that this toxin may contribute to damage during gastrointestinal infection. Conclusion This work presents a new mouse model of S. aureus gastrointestinal infection, while also providing insight into the pathogenesis of S. aureus in the gut.
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Affiliation(s)
- Sarah Larcombe
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Jhih-Hang Jiang
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Melanie L. Hutton
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Helen E. Abud
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
| | - Anton Y. Peleg
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
- *Correspondence: Dena Lyras,
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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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Tuffs SW, Haeryfar SMM, McCormick JK. Manipulation of Innate and Adaptive Immunity by Staphylococcal Superantigens. Pathogens 2018; 7:pathogens7020053. [PMID: 29843476 PMCID: PMC6027230 DOI: 10.3390/pathogens7020053] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/15/2018] [Accepted: 05/17/2018] [Indexed: 12/15/2022] Open
Abstract
Staphylococcal superantigens (SAgs) constitute a family of potent exotoxins secreted by Staphylococcus aureus and other select staphylococcal species. SAgs function to cross-link major histocompatibility complex (MHC) class II molecules with T cell receptors (TCRs) to stimulate the uncontrolled activation of T lymphocytes, potentially leading to severe human illnesses such as toxic shock syndrome. The ubiquity of SAgs in clinical S. aureus isolates suggests that they likely make an important contribution to the evolutionary fitness of S. aureus. Although the apparent redundancy of SAgs in S. aureus has not been explained, the high level of sequence diversity within this toxin family may allow for SAgs to recognize an assorted range of TCR and MHC class II molecules, as well as aid in the avoidance of humoral immunity. Herein, we outline the major diseases associated with the staphylococcal SAgs and how a dysregulated immune system may contribute to pathology. We then highlight recent research that considers the importance of SAgs in the pathogenesis of S. aureus infections, demonstrating that SAgs are more than simply an immunological diversion. We suggest that SAgs can act as targeted modulators that drive the immune response away from an effective response, and thus aid in S. aureus persistence.
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Affiliation(s)
- Stephen W Tuffs
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada.
| | - S M Mansour Haeryfar
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada.
- Division of Clinical Immunology and Allergy, Department of Medicine, Western University, London, ON N6A 3K7, Canada.
- Centre for Human Immunology, Western University, London, ON N6A 3K7, Canada.
- Lawson Health Research Institute, London, ON N6C 2R5, Canada.
| | - John K McCormick
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada.
- Centre for Human Immunology, Western University, London, ON N6A 3K7, Canada.
- Lawson Health Research Institute, London, ON N6C 2R5, Canada.
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Parker D. Humanized Mouse Models of Staphylococcus aureus Infection. Front Immunol 2017; 8:512. [PMID: 28523002 PMCID: PMC5415562 DOI: 10.3389/fimmu.2017.00512] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 04/18/2017] [Indexed: 12/18/2022] Open
Abstract
Staphylococcus aureus is a successful human pathogen that has adapted itself in response to selection pressure by the human immune system. A commensal of the human skin and nose, it is a leading cause of several conditions: skin and soft tissue infection, pneumonia, septicemia, peritonitis, bacteremia, and endocarditis. Mice have been used extensively in all these conditions to identify virulence factors and host components important for pathogenesis. Although significant effort has gone toward development of an anti-staphylococcal vaccine, antibodies have proven ineffective in preventing infection in humans after successful studies in mice. These results have raised questions as to the utility of mice to predict patient outcome and suggest that humanized mice might prove useful in modeling infection. The development of humanized mouse models of S. aureus infection will allow us to assess the contribution of several human-specific virulence factors, in addition to exploring components of the human immune system in protection against S. aureus infection. Their use is discussed in light of several recently reported studies.
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Affiliation(s)
- Dane Parker
- Department of Pediatrics, Columbia University, New York, NY, 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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van Gessel YA, Mani S, Bi S, Hammamieh R, Shupp JW, Das R, Coleman GD, Jett M. Functional Piglet Model for the Clinical Syndrome and Postmortem Findings Induced by Staphylococcal Enterotoxin B. Exp Biol Med (Maywood) 2016; 229:1061-71. [PMID: 15522843 DOI: 10.1177/153537020422901011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Staphylococcal enterotoxin (SE) B causes serious gastrointestinal illness, and intoxication with this exotoxin can lead to lethal toxic shock syndrome. In order to overcome significant shortcomings of current rodent and nonhuman primate models, we developed a piglet model of lethal SEB intoxication. Fourteen-day-old Yorkshire piglets were given intravenous SEB, observed clinically, and sacrificed at 4, 6, 24, 48, 72, or 96 hrs posttreatment. Clinical signs were biphasic with pyrexia, vomiting, and diarrhea within 4 hrs, followed by terminal hypotension and shock by 96 hrs. Mild lymphoid lesions were identified as early as 24 hrs, with severe lymphadenopathy, splenomegaly, and prominent Peyer's patches found by 72 hrs. Widespread edema—most prominent in the mesentery, between loops of spiral colon, and in retroperitoneal connective tissue—was found in animals at 72 hrs. Additional histologic changes included perivascular aggregates of large lymphocytes variably present in the lung and brain, circulating lymphoblasts, and lymphocytic portal hepatitis. Preliminary molecular investigation using gene array has uncovered several gene profile changes that may have implications in the pathophysiology leading to irreversible shock. Five genes were selected for further study, and all showed increased mRNA levels subsequent to SEB exposure. The use of this piglet model will continue to elucidate the pathogenesis of SEB intoxication and facilitate the testing of new therapeutic regimens that may better correlate with human lesions.
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Affiliation(s)
- Yvonne A van Gessel
- Division of Pathology, Department of Molecular Pathology, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
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Koymans KJ, Vrieling M, Gorham RD, van Strijp JAG. Staphylococcal Immune Evasion Proteins: Structure, Function, and Host Adaptation. Curr Top Microbiol Immunol 2015; 409:441-489. [PMID: 26919864 DOI: 10.1007/82_2015_5017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Staphylococcus aureus is a successful human and animal pathogen. Its pathogenicity is linked to its ability to secrete a large amount of virulence factors. These secreted proteins interfere with many critical components of the immune system, both innate and adaptive, and hamper proper immune functioning. In recent years, numerous studies have been conducted in order to understand the molecular mechanism underlying the interaction of evasion molecules with the host immune system. Structural studies have fundamentally contributed to our understanding of the mechanisms of action of the individual factors. Furthermore, such studies revealed one of the most striking characteristics of the secreted immune evasion molecules: their conserved structure. Despite high-sequence variability, most immune evasion molecules belong to a small number of structural categories. Another remarkable characteristic is that S. aureus carries most of these virulence factors on mobile genetic elements (MGE) or ex-MGE in its accessory genome. Coevolution of pathogen and host has resulted in immune evasion molecules with a highly host-specific function and prevalence. In this review, we explore how these shared structures and genomic locations relate to function and host specificity. This is discussed in the context of therapeutic options for these immune evasion molecules in infectious as well as in inflammatory diseases.
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Affiliation(s)
- Kirsten J Koymans
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
| | - Manouk Vrieling
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Ronald D Gorham
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Jos A G van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
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Zheng L, Xing L, Zeng C, Wu T, Gui Y, Li W, Lan T, Yang Y, Gu Q, Qi C, Zhang Q, Tang F, He X, Wang L. Inactivation of PI3Kδ induces vascular injury and promotes aneurysm development by upregulating the AP-1/MMP-12 pathway in macrophages. Arterioscler Thromb Vasc Biol 2014; 35:368-77. [PMID: 25503990 DOI: 10.1161/atvbaha.114.304365] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE An aneurysm is an inflammatory vascular condition. Phosphatidylinositol 3-kinases δ is highly expressed in leukocytes, and play a key role in innate immunity. However, the link between phosphatidylinositol 3-kinases δ and aneurysm development has not yet been elucidated. APPROACH AND RESULTS Carotid ligation unexpectedly induced characteristic aneurysm formation beneath the ligation point in p110δ(D910A/D910A) mice (n=25; P<0.001 versus wild-type). Besides, p110δ inactivation exacerbated CaCl2-induced abdominal aortic aneurysms development. A reverse transcription polymerase chain reaction microarray revealed significant extracellular matrix components degradation and matrix metalloproteinases (MMPs) upregulation in the abdominal aorta of p110δ(D910A/D910A) mice. Similarly, the expression of both collagen I and IV was significantly decreased (n=10; P<0.05 versus wild-type) in carotid artery. Western blot assay confirmed that MMP-12 was significantly upregulated in arteries of p110δ(D910A/D910A) mice (n=10; P<0.01 versus wild-type). In vitro, p110δ inactivation marked increase peritoneal macrophages recruitment and synergistically enhance tumor necrosis factor-α-induced recruitment. A specific phosphatidylinositol 3-kinases δ inhibitor (IC87114) or genetic p110δ inactivation upregulated MMP-12 expression and c-Jun phosphorylation (n=6; P<0.05 versus wild-type macrophages). IC87114 also increased activator protein-1 DNA-binding activity (n=6; P<0.001 versus control) and enhanced the effect of tumor necrosis factor-α on activator protein-1-binding activity (n=5; P<0.01 versus tumor necrosis factor-α treatment groups). Knockdown of c-Jun suppressed the effect of the IC87114 and tumor necrosis factor-α on MMP-12 mRNA expression (n=5 in each group; P<0.01 versus scrRNA treatment groups). CONCLUSIONS Our findings demonstrate that p110δ inactivation leads to extracellular matrix degradation in vessels and promotes aneurysm development by inducing macrophages migration and upregulating the activator protein-1/MMP-12 pathway in macrophages.
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Affiliation(s)
- Lingyun Zheng
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Liying Xing
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Cuiling Zeng
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Teng Wu
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Yali Gui
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Weidong Li
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Tian Lan
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Yongxia Yang
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Quliang Gu
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Cuiling Qi
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Qianqian Zhang
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Futian Tang
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Xiaodong He
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China
| | - Lijing Wang
- From the Vascular Biology Research Institute (L.Z., L.X., C.Z., T.W., Y.G., W.L., T.L., Y.Y., Q.G., C.Q., Q.Z., F.T., X.H., L.W.) and Department of Basic Course (L.Z., Y.Y., Q.G.), Guangdong Pharmaceutical University, Guangzhou 510006, P.R. China.
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Models matter: the search for an effective Staphylococcus aureus vaccine. Nat Rev Microbiol 2014; 12:585-91. [PMID: 24998740 DOI: 10.1038/nrmicro3308] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Staphylococcus aureus is a highly successful bacterial pathogen owing to its abundance of cell surface and secreted virulence factors. It is estimated that 30% of the population is colonized with S. aureus, usually on mucosal surfaces, and methicillin-resistant S. aureus is a major public health concern. There have been multiple attempts to develop an S. aureus vaccine using one or more cell surface virulence factors as antigens; all of these vaccine trials have failed. In this Opinion article, we suggest that an over-reliance on rodent models and a focus on targeting cell surface components have been major contributing factors to this failure.
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Superantigens subvert the neutrophil response to promote abscess formation and enhance Staphylococcus aureus survival in vivo. Infect Immun 2014; 82:3588-98. [PMID: 24914221 DOI: 10.1128/iai.02110-14] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Staphylococcus aureus is a versatile bacterial pathogen that produces T cell-activating toxins known as superantigens (SAgs). Although excessive immune activation by SAgs can induce a dysregulated cytokine storm as a component of what is known as toxic shock syndrome (TSS), the contribution of SAgs to the staphylococcal infection process is not well defined. Here, we evaluated the role of the bacterial superantigen staphylococcal enterotoxin A (SEA) in a bacteremia model using humanized transgenic mice expressing SAg-responsive HLA-DR4 molecules. Infection with S. aureus Newman induced SEA-dependent Vβ skewing of T cells and enhanced bacterial survival in the liver compared with infection by sea knockout strain. SEA-induced gamma interferon, interleukin-12, and chemokine responses resulted in increased infiltration of CD11b(+) Ly6G(+) neutrophils into the liver, promoting the formation of abscesses that contained large numbers of viable staphylococci. Hepatic abscesses occurred significantly more frequently in S. aureus Newman-infected livers than in livers infected with the Newman sea knockout strain, promoting the survival of S. aureus in vivo. This represents a novel mechanism during infection whereby S. aureus utilizes SAgs to form a specialized niche and manipulate the immune system.
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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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14
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Abstract
Staphylococcus aureus plays an important role in numerous human cases of food poisoning, soft tissue, and bone infections, as well as potentially lethal toxic shock. This common bacterium synthesizes various virulence factors that include staphylococcal enterotoxins (SEs). These protein toxins bind directly to major histocompatibility complex class II on antigen-presenting cells and specific Vβ regions of T-cell receptors, resulting in potentially life-threatening stimulation of the immune system. Picomolar concentrations of SEs ultimately elicit proinflammatory cytokines that can induce fever, hypotension, multi-organ failure, and lethal shock. Various in vitro and in vivo models have provided important tools for studying the biological effects of, as well as potential vaccines/therapeutics against, the SEs. This review succinctly presents known physical and biological properties of the SEs, including various intervention strategies. In particular, SEB will often be portrayed as per biodefense concerns dating back to the 1960s.
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Affiliation(s)
- Teresa Krakauer
- Integrated Toxicology Division; United States Army Medical Research Institute of Infectious Diseases; Fort Detrick, MD USA
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15
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Krakauer T, Buckley M. Intranasal rapamycin rescues mice from staphylococcal enterotoxin B-induced shock. Toxins (Basel) 2012; 4:718-28. [PMID: 23105977 PMCID: PMC3475225 DOI: 10.3390/toxins4090718] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 08/06/2012] [Accepted: 08/13/2012] [Indexed: 12/24/2022] Open
Abstract
Staphylococcal enterotoxin B (SEB) and related exotoxins produced by Staphylococcus aureus are potent activators of the immune system and cause toxic shock in humans. Currently there is no effective treatment except for the use of intravenous immunoglobulins administered shortly after SEB exposure. Intranasal SEB induces long-lasting lung injury which requires prolonged drug treatment. We investigated the effects of rapamycin, an immunosuppressive drug used to prevent graft rejection, by intranasal administration in a lethal mouse model of SEB-induced shock. The results show that intranasal rapamycin alone delivered as late as 17 h after SEB protected 100% of mice from lethal shock. Additionally, rapamycin diminished the weight loss and temperature fluctuations elicited by SEB. Intranasal rapamycin attenuated lung MCP-1, IL-2, IL-6, and IFNγ by 70%, 30%, 64%, and 68% respectively. Furthermore, short courses (three doses) of rapamycin were sufficient to block SEB-induced shock. Intranasal rapamycin represents a novel use of an immunosuppressant targeting directly to site of toxin exposure, reducing dosages needed and allowing a wider therapeutic window.
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Affiliation(s)
- Teresa Krakauer
- Integrated Toxicology Division, U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA.
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16
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Xu SX, McCormick JK. Staphylococcal superantigens in colonization and disease. Front Cell Infect Microbiol 2012; 2:52. [PMID: 22919643 PMCID: PMC3417409 DOI: 10.3389/fcimb.2012.00052] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 03/29/2012] [Indexed: 12/28/2022] Open
Abstract
Superantigens (SAgs) are a family of potent immunostimulatory exotoxins known to be produced by only a few bacterial pathogens, including Staphylococcus aureus. More than 20 distinct SAgs have been characterized from different S. aureus strains and at least 80% of clinical strains harbor at least one SAg gene, although most strains encode many. SAgs have been classically associated with food poisoning and toxic shock syndrome (TSS), for which these toxins are the causative agent. TSS is a potentially fatal disease whereby SAg-mediated activation of T cells results in overproduction of cytokines and results in systemic inflammation and shock. Numerous studies have also shown a possible role for SAgs in other diseases such as Kawasaki disease (KD), atopic dermatitis (AD), and chronic rhinosinusitis (CRS). There is also now a rich understanding of the mechanisms of action of SAgs, as well as their structures and function. However, we have yet to discover what purpose SAgs play in the life cycle of S. aureus, and why such a wide array of these toxins exists. This review will focus on recent developments within the SAg field in terms of the molecular biology of these toxins and their role in both colonization and disease.
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Affiliation(s)
- Stacey X Xu
- Department of Microbiology and Immunology, Centre for Human Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, London ON, Canada
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17
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Abstract
Survival during sepsis requires both swift control of infectious organisms and tight regulation of the associated inflammatory response. As the role of T cells in sepsis is somewhat controversial, we examined the impact of increasing antigen-dependent activation of CD4 T cells in a murine model of cecal ligation and puncture using T-cell receptor transgenic II (OT-II) mice that are specific for chicken ovalbumin (OVA) in the context of major histocompatibility complex II. Here, we injected OT-II mice with 0, 1, or 100 μg of OVA and demonstrate that increased antigen treatment resulted in increased numbers of activated splenic CD4 T cells. Vehicle-treated, septic OT-II mice had decreased survival, increased bacterial load, and increased levels of IL-6. Interestingly, this decrease in survival was abrogated when OT-II mice were injected with 1 μg OVA, which was correlated with normalized bacterial load and levels of IL-6. However, when OT-II mice were injected with 100 μg OVA, decreased survival was restored but, in contrast to vehicle-treated OT-II mice, had decreased bacterial load and enhanced IL-6 levels. We also observed that neutrophil oxidative burst and phagocytosis were dependent on CD4 T-cell activation. Further, at extreme levels of T-cell activation, intestinal permeability was significantly increased. Altogether, we conclude that too little CD4 T-cell activation produces dysfunctional neutrophils leading to decreased bacteria clearance and survival, whereas too much CD4 T-cell activation produces a neutrophil phenotype that leads to efficient bacterial clearance but with increased tissue damage and mortality.
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Therapeutic down-modulators of staphylococcal superantigen-induced inflammation and toxic shock. Toxins (Basel) 2010; 2:1963-83. [PMID: 22069668 PMCID: PMC3153276 DOI: 10.3390/toxins2081963] [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: 06/30/2010] [Revised: 07/16/2010] [Accepted: 07/28/2010] [Indexed: 12/21/2022] Open
Abstract
Staphylococcal enterotoxin B (SEB) and related superantigenic toxins are potent stimulators of the immune system and cause a variety of diseases in humans, ranging from food poisoning to toxic shock. These toxins bind directly to 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 monocytes/macrophages and T lymphocytes. Activated host cells produce massive amounts of proinflammatory cytokines and chemokines, activating inflammation and coagulation, causing clinical symptoms that include fever, hypotension, and shock. This review summarizes the in vitro and in vivo effects of staphylococcal superantigens, the role of pivotal mediators induced by these toxins in the pathogenic mechanisms of tissue injury, and the therapeutic agents to mitigate the toxic effects of superantigens.
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Rapamycin protects mice from staphylococcal enterotoxin B-induced toxic shock and blocks cytokine release in vitro and in vivo. Antimicrob Agents Chemother 2010; 54:1125-31. [PMID: 20086156 DOI: 10.1128/aac.01015-09] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Staphylococcal enterotoxins are potent activators for human T cells and cause lethal toxic shock. Rapamycin, an immunosuppressant, was tested for its ability to inhibit staphylococcal enterotoxin B (SEB)-induced activation of human peripheral blood mononuclear cells (PBMC) in vitro and toxin-mediated shock in mice. Stimulation of PMBC by SEB was effectively blocked by rapamycin as evidenced by the inhibition of tumor necrosis factor alpha (TNF-alpha), interleukin 1beta (IL-1beta), IL-6, IL-2, gamma interferon (IFN-gamma), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, and T-cell proliferation. In vivo, rapamycin protected 100% of mice from lethal shock, even when administered 24 h after intranasal SEB challenge. The serum levels of MCP-1 and IL-6, after intranasal exposure to SEB, were significantly reduced in mice given rapamycin versus controls. Additionally, rapamycin diminished the weight loss and temperature fluctuations elicited by SEB.
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Xiong W, MacTaggart J, Knispel R, Worth J, Persidsky Y, Baxter BT. Blocking TNF-alpha attenuates aneurysm formation in a murine model. THE JOURNAL OF IMMUNOLOGY 2009; 183:2741-6. [PMID: 19620291 DOI: 10.4049/jimmunol.0803164] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Abdominal aortic aneurysm (AAA) is one of a number of diseases associated with a prominent inflammatory cell infiltrate and local destruction of structural matrix macromolecules. This chronic infiltrate is predominately composed of macrophages and T lymphocytes. Activated macrophages produce a variety of cytokines, including TNF-alpha. Elevated levels of TNF-alpha were observed in patients with AAA, suggesting that TNF-alpha may play a role in the pathogenic mechanisms of AAA. In the present study, we investigated the role of TNF-alpha in AAA formation. By studying a murine aneurysm model, we found that both mRNA and protein levels of TNF-alpha were increased in aneurysm tissue compared with normal aortic tissues. Therefore, we tested the response of mice lacking expression of TNF-alpha. These mice were resistant to aneurysm formation. Our results show that TNF-alpha deficiency attenuates matrix metalloproteinase (MMP) 2 and MMP-9 expression and macrophage infiltration into the aortic tissue. These data suggest that TNF-alpha plays a central role in regulating matrix remodeling and inflammation in the aortic wall leading to AAA. In addition, we investigated the pharmacological inhibition of AAA. A Food and Drug Administration-approved TNF-alpha antagonist, infliximab, inhibited aneurysm growth. Our data also show that infliximab treatment attenuated elastic fiber disruption, macrophage infiltration, and MMP-2 and MMP-9 expression in aortic tissue. This study confirms that a strategy of TNF-alpha antagonism may be an important therapeutic strategy for treating AAA.
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Affiliation(s)
- Wanfen Xiong
- Department of Surgery, University of Nebraska Medical Center, Omaha,NE 68198, USA
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21
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Krakauer T, Buckley MJ, Huzella LM, Alves DA. Critical timing, location and duration of glucocorticoid administration rescue mice from superantigen-induced shock and attenuate lung injury. Int Immunopharmacol 2009; 9:1168-74. [PMID: 19539058 DOI: 10.1016/j.intimp.2009.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 06/07/2009] [Accepted: 06/09/2009] [Indexed: 11/16/2022]
Abstract
Bacterial superantigens, such as staphylococcal enterotoxin B (SEB), are major virulence factors implicated in the pathogenesis of toxic shock. In this study we investigated the efficacy of glucocorticoid therapy in preventing SEB-induced lethal shock initiated through the respiratory route in mice. Dexamethasone, a potent anti-inflammatory steroid, administrated intranasally on the first day, followed by intraperitoneal doses on the subsequent 4 days, was effective in attenuating SEB-induced hypothermia, and reduction in systemic and pulmonary proinflammatory mediator release. This optimal dosing and schedule of glucocorticoid treatment mitigated lung inflammation and resulted in 100% survival in this intranasal mouse model of SEB-mediated shock.
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Affiliation(s)
- Teresa Krakauer
- Integrated Toxicology Division, USAMRIID, Fort Detrick, MD 21702-5011, USA.
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22
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Plaza R, Rodriguez-Sanchez JL, Juarez C. Staphylococcal enterotoxin B in vivo modulates both gamma interferon receptor expression and ligand-induced activation of signal transducer and activator of transcription 1 in T cells. Infect Immun 2007; 75:306-13. [PMID: 17074848 PMCID: PMC1828398 DOI: 10.1128/iai.01220-06] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2006] [Revised: 09/15/2006] [Accepted: 10/19/2006] [Indexed: 01/24/2023] Open
Abstract
Superantigens (SAg) are bacterial exotoxins that provoke extreme responses in the immune system; for example, the acute hyperactivation of SAg-reactive T cells that leads to toxic shock syndrome is followed within days by strong immunosuppression. The gamma interferon (IFN-gamma) response is deeply affected in both extremes. The implication of IFN-gamma in the pathophysiology of lethal shock induced in mice after a secondary challenge with the SAg staphylococcal enterotoxin B (SEB) prompted us to study the regulation of IFN-gamma secretion and the intracellular response. We demonstrate in this study that a rechallenge with SEB becomes lethal only when given inside a critical time window after SEB priming and is associated with an increase of IFN-gamma serum release 72 h after priming. However, at this time, a selective blockade of IFN-gamma/STAT1 signaling develops in spleen cells, correlating with a lack of expression of the IFN-gamma receptor beta subunit and STAT1 in the T-cell population. Selective blockade of the STAT1 signaling pathway--while simultaneously maintaining STAT3 signaling and expression--may be a protective mechanism that shortens IFN-gamma production during the Th1 effector response. This blockade may also have consequences on switching towards a suppressor phenotype with chronic exposure to the superantigen.
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Affiliation(s)
- R Plaza
- Department of Immunology, Hospital de la Santa Creu i Sant Pau, Avda. Sant Antoni Maria Claret 167, 08025 Barcelona, Spain
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Rajagopalan G, Smart MK, Patel R, David CS. Acute systemic immune activation following conjunctival exposure to staphylococcal enterotoxin B. Infect Immun 2006; 74:6016-9. [PMID: 16988282 PMCID: PMC1594882 DOI: 10.1128/iai.00671-06] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Conjunctival exposure to the Staphylococcus aureus superantigen staphylococcal enterotoxin B (SEB) may occur accidentally, as a result of bioterrorism, or during colonization or infection of the external eye. Using human leukocyte antigen class II transgenic mice, we show for the first time that conjunctival exposure to SEB can cause robust systemic immune activation.
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Affiliation(s)
- Govindarajan Rajagopalan
- Department of Immunology, Mayo Clinic College of Medicine, 200 First St., SW, Rochester, MN 55905, USA
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24
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Hui-Yuen JS, Duong TT, Yeung RSM. TNF-alpha is necessary for induction of coronary artery inflammation and aneurysm formation in an animal model of Kawasaki disease. THE JOURNAL OF IMMUNOLOGY 2006; 176:6294-301. [PMID: 16670341 DOI: 10.4049/jimmunol.176.10.6294] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Kawasaki disease is the most common cause of multisystem vasculitis in childhood. The resultant coronary artery lesions make Kawasaki disease the leading cause of acquired heart disease in children in the developed world. TNF-alpha is a pleiotropic inflammatory cytokine elevated during the acute phase of Kawasaki disease. In this study, we report rapid production of TNF-alpha in the peripheral immune system after disease induction in a murine model of Kawasaki disease. This immune response becomes site directed, with migration to the coronary arteries dependent on TNF-alpha-mediated events. Production of TNF-alpha in the heart is coincident with the presence of inflammatory infiltrate at the coronary arteries, which persists during development of aneurysms. More importantly, inflammation and elastin breakdown in the coronary vessels are completely eliminated in the absence of TNF-alpha effector functions. Mice treated with the TNF-alpha-blocking agent etanercept, as well as TNFRI knockout mice, are resistant to development of both coronary arteritis and coronary aneurysm formation. Taken together, TNF-alpha is necessary for the development of coronary artery lesions in an animal model of Kawasaki disease. These findings have important implications for potential new therapeutic interventions in children with Kawasaki disease.
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Affiliation(s)
- Joyce S Hui-Yuen
- Cancer Research Program, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario, Canada
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25
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Rajagopalan G, Sen MM, Singh M, Murali NS, Nath KA, Iijima K, Kita H, Leontovich AA, Gopinathan U, Patel R, David CS. INTRANASAL EXPOSURE TO STAPHYLOCOCCAL ENTEROTOXIN B ELICITS AN ACUTE SYSTEMIC INFLAMMATORY RESPONSE. Shock 2006; 25:647-56. [PMID: 16721274 DOI: 10.1097/01.shk.0000209565.92445.7d] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Staphylococcus aureus produces a variety of superantigen exotoxins, including staphylococcal enterotoxin B (SEB). Little is known regarding the pathogenesis of SEB entering through the intranasal route. Intranasal exposure to SEB might occur because of nasal packing following surgical procedure, biologic warfare, or even S. aureus colonization. We evaluated the local and systemic effects of intranasally delivered SEB using a series of human leukocyte antigen (HLA) class II transgenic mice as conventional mice expressing endogenous class II molecules mount a poor immune response to SEB. Gene expression profiling using microarrays showed robust up-regulation of genes involved in several proinflammatory pathways as early as 3 h post-intranasal challenge with SEB in HLA class II transgenic mice. This was accompanied by a several hundred-fold increase in serum levels of pro-inflammatory cytokines such as IL-12, IL-6, TNF-alpha, IFN-gamma, as well as MCP-1 in HLA class II transgenic mice but not in C57BL/6 mice; CD4 or CD8 T-cells independently contributed to the systemic cytokine response. Defective IL-12 or IL-4 receptor signaling significantly decreased or increased serum IFN-gamma, respectively. Intranasal exposure to SEB resulted in neutrophil influx into bronchoalveolar lavage fluid and caused expansion of both CD4 and CD8 T-cells expressing TCR V beta 8 in the spleen. This was accompanied by mononuclear cell infiltration in the liver reminiscent of the systemic inflammatory response syndrome. Thus, we have shown, for the first time, that intranasal administration of SEB can cause systemic immune activation.
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Rajagopalan G, Iijima K, Singh M, Kita H, Patel R, David CS. Intranasal exposure to bacterial superantigens induces airway inflammation in HLA class II transgenic mice. Infect Immun 2006; 74:1284-96. [PMID: 16428778 PMCID: PMC1360368 DOI: 10.1128/iai.74.2.1284-1296.2006] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus is widely prevalent in the nasopharynges of healthy individuals (carriers) but can also cause serious infections. S. aureus can elaborate a variety of superantigen exotoxins in "carrier" or "pathogenic" states. Streptococcus pyogenes can also colonize the nasopharynx and elaborate superantigens. Unlike the acute effects of superantigen exotoxins absorbed through the gut or vaginal mucosa, little is known regarding the pathogenesis of superantigens entering through the intranasal route. In the current study, we evaluated the local and systemic effects of staphylococcal enterotoxin B (SEB) and streptococcal pyrogenic exotoxin A (SPEA) delivered through the intranasal route. Superantigens were administered intranasally on multiple occasions, and experimental animals were sacrificed on day 8 for experimental analyses. SEB-induced airway inflammation was more pronounced for HLA-DR3 transgenic mice than for BALB/c mice, consistent with bacterial superantigens binding more efficiently to human than murine major histocompatibility complex class II. The nature of the airway inflammation in HLA-DR3 mice was determined by the concentration of SEB applied intranasally. Low concentrations (20 ng) induced eosinophilic airway inflammation as well as eosinophil degranulation, whereas intranasal exposure to higher concentrations (2,000 ng) resulted in neutrophilic airway inflammation, permanent airway destruction, toxic shock, and mortality. SEB-induced eosinophilic inflammatory response was enhanced in signal transducer and activator of transcription (STAT)-4-deficient HLA-DQ8 transgenic mice with defective interleukin-12 signaling. Intranasal administration of SPEA induced airway inflammation and systemic immune activation in HLA-DQ8 transgenic mice. In conclusion, repeated chronic intranasal exposure to bacterial superantigens causes airway inflammation and systemic immune activation.
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Affiliation(s)
- Govindarajan Rajagopalan
- Department of Immunology, Mayo Clinic College of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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27
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Faulkner L, Cooper A, Fantino C, Altmann DM, Sriskandan S. The mechanism of superantigen-mediated toxic shock: not a simple Th1 cytokine storm. THE JOURNAL OF IMMUNOLOGY 2006; 175:6870-7. [PMID: 16272345 DOI: 10.4049/jimmunol.175.10.6870] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The profound clinical consequences of Gram-positive toxic shock are hypothesized to stem from excessive Th1 responses to superantigens. We used a new superantigen-sensitive transgenic model to explore the role of TCRalphabeta T cells in responses to staphylococcal enterotoxin B (SEB) in vitro and in two different in vivo models. The proliferative and cytokine responses of HLA-DR1 spleen cells were 100-fold more sensitive than controls and were entirely dependent on TCRalphabeta T cells. HLA-DR1 mice showed greater sensitivity in vivo to two doses of SEB with higher mortality and serum cytokines than controls. When d-galactosamine was used as a sensitizing agent with a single dose of SEB, HLA-DR1 mice died of toxic shock whereas controls did not. In this sensitized model of toxic shock there was a biphasic release of cytokines, including TNF-alpha, at 2 h and before death at 7 h. In both models, mortality and cytokine release at both time points were dependent on TCRalphabeta T cells. Anti-TNF-alpha pretreatment was protective against shock whereas anti-IFN gamma pretreatment and delayed anti-TNF-alpha treatment were not. Importantly, anti-TNF-alpha pretreatment inhibited the early TNF-alpha response but did not inhibit the later TNF-alpha burst, to which mortality has previously been attributed. Splenic T cells were shown definitively to be the major source of TNF-alpha during the acute cytokine response. Our results demonstrate unequivocally that TCRalphabeta T cells are critical for lethality in toxic shock but it is the early TNF-alpha response and not the later cytokine surge that mediates lethal shock.
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MESH Headings
- Animals
- Cytokines/biosynthesis
- Enterotoxins/toxicity
- Galactosamine/toxicity
- HLA-DR1 Antigen/genetics
- HLA-DR1 Antigen/metabolism
- Humans
- Mice
- Mice, Knockout
- Mice, Transgenic
- Receptors, Antigen, T-Cell, alpha-beta/deficiency
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Shock, Septic/etiology
- Shock, Septic/immunology
- Spleen/drug effects
- Spleen/immunology
- Superantigens/toxicity
- Th1 Cells/drug effects
- Th1 Cells/immunology
- Tumor Necrosis Factor-alpha/biosynthesis
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Affiliation(s)
- Lee Faulkner
- Department of Infectious Diseases, Imperial College London, London, United Kingdom
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28
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Rajagopalan G, Singh M, Sen MM, Murali NS, Nath KA, David CS. Endogenous superantigens shape response to exogenous superantigens. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2005; 12:1119-22. [PMID: 16148182 PMCID: PMC1235787 DOI: 10.1128/cdli.12.9.1119-1122.2005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Endogenous superantigen-mediated thymic negative selection resulted in a paucity of mature T cells bearing T-cell receptor (TCR) Vbeta8 in the periphery. Consequently, the magnitude of immune response to exogenous superantigen staphylococcal enterotoxin B, which activates TCR Vbeta8(+) T cells, was significantly reduced and conferred protection from superantigen-induced mortality.
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Affiliation(s)
- Govindarajan Rajagopalan
- Department of Immunology, Mayo Clinic College of Medicine, Mayo Clinic, SW, Rochester, MN 55905, USA
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29
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Rajagopalan G, Sen MM, David CS. In vitro and in vivo evaluation of staphylococcal superantigen peptide antagonists. Infect Immun 2004; 72:6733-7. [PMID: 15501813 PMCID: PMC522998 DOI: 10.1128/iai.72.11.6733-6737.2004] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Superantigen peptide antagonists failed to block T-cell activation and cytokine production as well as toxic shock induced by staphylococcal enterotoxin B (SEB) in HLA class II transgenic mice. They also failed to inhibit the binding of SEB to HLA class II molecules as well as activation of human T lymphocytes in vitro.
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Affiliation(s)
- Govindarajan Rajagopalan
- Department of Immunology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN 55905, USA
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30
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Lingappa J, Kuffner T, Tappero J, Whitworth W, Mize A, Kaiser R, McNicholl J. HLA-DQ6 and ingestion of contaminated water: possible gene-environment interaction in an outbreak of Leptospirosis. Genes Immun 2004; 5:197-202. [PMID: 15014429 DOI: 10.1038/sj.gene.6364058] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Leptospirosis is a zoonosis that can cause severe multisystem disease. While host gene-environment interactions likely modify infectious disease susceptibility, including for leptopsirosis, this has not been documented. In a 1998 leptospirosis outbreak investigation among triathletes in a lake swim, swallowing lake-water was a disease risk-factor. We used genomic DNA from 85 anonymized blood-sample remainders from that investigation to examine the association of laboratory-confirmed leptospirosis with gene polymorphisms (TNF-alpha alleles and serologically defined genotypes for HLA-DRB1 and HLA-DQB1). HLA-DQ6-positive triathletes had increased risk of laboratory-confirmed leptospirosis (OR=2.8, P=0.04) compared to DQ6-negatives. DQ6-positive triathletes swallowing lake-water had greatest risk (OR 8.46, P< or =0.001). This first report of a genetic risk-factor affecting susceptibility to leptospirosis is also the first documented gene-environment interaction (DQ6 and swallowed water) affecting infectious disease susceptibility. Based on these preliminary findings, we hypothesize a role for superantigens in leptospirosis and underscore the importance of outbreak investigations for understanding infectious disease gene-environment interactions.
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Affiliation(s)
- J Lingappa
- Division of Bacterial and Mycotic Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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31
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Chan WC, Duong TT, Yeung RSM. Presence of IFN-gamma does not indicate its necessity for induction of coronary arteritis in an animal model of Kawasaki disease. THE JOURNAL OF IMMUNOLOGY 2004; 173:3492-503. [PMID: 15322214 DOI: 10.4049/jimmunol.173.5.3492] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Kawasaki disease is the most common cause of vasculitis affecting children, and the leading cause of acquired heart disease in the developed world. To date, studies on the role of IFN-gamma in the pathogenesis of Kawasaki disease have focused on peripheral production of IFN-gamma, and have yielded conflicting results. Affected heart tissue is not available from children with Kawasaki disease. In this study, we use an animal model of Kawasaki disease, Lactobacillus casei cell wall extract (LCWE)-induced coronary arteritis, to examine the role of IFN-gamma in the development of coronary artery lesions. We report the presence of IFN-gamma, both at the mRNA and protein levels, in the affected vessels. Its biphasic expression, first at days 3-7 and again at days 28-42 post-LCWE injection, corresponds to the first appearance of inflammatory infiltrate in coronary arteries, and later to vascular wall disruption and aneurysm formation, respectively. Interestingly, ablation of IFN-gamma expression did not dampen the inflammatory response, and IFN-gamma-deficient lymphocytes proliferated more vigorously in response to LCWE than those of wild-type animals. Of more importance, the incidence of coronary arteritis was the same in IFN-gamma-deficient and wild-type mice. Taken together, our findings demonstrate that IFN-gamma regulates the immune response during development of coronary arteritis, but is not required for the induction of coronary artery disease.
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Affiliation(s)
- Wesley C Chan
- Division of Cancer Research, Hospital for Sick Children Research Institute, Toronto, Canada
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32
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Savransky V, Rostapshov V, Pinelis D, Polotsky Y, Korolev S, Komisar J, Fegeding K. Murine lethal toxic shock caused by intranasal administration of staphylococcal enterotoxin B. Toxicol Pathol 2003; 31:373-8. [PMID: 12851102 DOI: 10.1080/01926230390201093] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Currently available murine staphylococcal enterotoxin B (SEB) shock models require pretreatment with various agents to increase mouse sensitivity to SEB. This study was performed to show that C3H/HeJ mice are highly susceptible to intranasal SEB inoculation, which caused toxic shock without using pretreatment agents. For this purpose, mice were injected intranasally with different doses of SEB and observed for up to 1 month. The median lethal dose of SEB was determined using the probit procedure. Tissue samples were taken at different time points for histopathological examination. The LD(50) was found at 1.6 microg/g (95% fiducial limit (f.l.) 0.7 to 2.2), the LD(80) at 2.7 microg/g (95% f.l. 1.9 to 4.0) and the LD(90) at 3.6 microg/g (95% f.l. 2.7 to 6.4). Histopathologic examination revealed pulmonary edema and bronchopneumonia. Mucosal-associated lymphoid tissue first became activated, followed by increasing lymphocyte apoptosis and depletion. In the liver there were intralobular and portal inflammatory foci with increasing lymphocyte apoptosis and degenerative necrosis. The splenic white pulp was characterized by early activation and subsequent depletion of lymphoid follicle germinal centers. The thymus initially was activated, followed by increasing apoptosis and migration of lymphoid cells from the cortex to the medulla. The pathological features detected in the mice were similar to those of rhesus monkeys treated with SEB aerosol challenge.
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Affiliation(s)
- Vladimir Savransky
- Department of Experimental Pathology, Division of Pathology, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, USA
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33
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Chapoval SP, Marietta EV, Smart MK, David CS. Requirements for allergen-induced airway inflammation and hyperreactivity in CD4-deficient and CD4-sufficient HLA-DQ transgenic mice. J Allergy Clin Immunol 2001; 108:764-71. [PMID: 11692102 DOI: 10.1067/mai.2001.118794] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Airway inflammation is central to the pathogenesis of allergic asthma, and molecules that mediate this process obviously represent targets for therapy. OBJECTIVE To study the role of CD4(+) T cells and/or HLA-DQ molecules in allergic asthma, we have generated and characterized models of short ragweed allergen (SRW)-induced inflammation using transgenic mice with HLA-DQ (DQ6 or DQ8), human CD4 (hCD4), or both on a genetic background that lacks mouse MHC II and CD4 (Abeta(0)/mCD4(0)). METHODS Mice were actively sensitized and later challenged intranasally with SRW allergenic extract. Bronchoalveolar lavage fluid composition, airway inflammation and hyperresponsiveness, blood eosinophil levels, and cell proliferation were examined. RESULTS In response to SRW treatment, both DQ6 and DQ8 transgenic mice expressing hCD4 developed pulmonary eosinophilia and associated lung tissue damage with increase in eosinophil peroxidase and T(H)2 cytokines in bronchoalveolar lavage fluid, strong airway hyperreactivity, and persistent blood eosinophilia. The response was independent of mast cells/histamine pathway and was mediated by DQ-restricted hCD4(+) T cells. Interestingly, lungs of CD4-deficient DQ6 transgenic mice showed an eosinophilic inflammation without local increase in cytokines and eosinophil peroxidase. The allergic reaction was absent in double-knockout mice and mice expressing either DQ8 or hCD4 alone. CONCLUSIONS DQ6 molecules are critical to SRW-induced allergy and can operate in the presence or absence of CD4. However, both DQ antigens and CD4 molecules are critical for full manifestation of allergen-induced asthma in transgenic mice.
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Affiliation(s)
- S P Chapoval
- Department of Immunology, Mayo Clinic, Rochester, MN 55905, USA
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34
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Dinges MM, Schlievert PM. Comparative analysis of lipopolysaccharide-induced tumor necrosis factor alpha activity in serum and lethality in mice and rabbits pretreated with the staphylococcal superantigen toxic shock syndrome toxin 1. Infect Immun 2001; 69:7169-72. [PMID: 11598096 PMCID: PMC100117 DOI: 10.1128/iai.69.11.7169-7172.2001] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Host susceptibility to lipopolysaccharide (LPS) is correlated with the levels of circulating tumor necrosis factor alpha (TNF-alpha) that develop in response to circulating LPS. Mice are resistant, relative to rabbits, to the lethal effects of LPS. This study indicates that mice and rabbits are equally sensitive to the lethal effects of circulating TNF-alpha but that mice are more resistant than rabbits to the induction of circulating TNF-alpha by LPS.
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Affiliation(s)
- M M Dinges
- Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
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35
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Taylor JV, Gordon LE, Polk HC. Early decrease in surface expression of HLA-DQ predicts the development of infection in trauma patients. Clin Exp Immunol 2000; 122:308-11. [PMID: 11122233 PMCID: PMC1905804 DOI: 10.1046/j.1365-2249.2000.01397.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The behaviour of human leucocyte antigen-DR (HLA-DR) following injury has been extensively studied. However, the behaviour of other class II antigens following trauma has not been characterized as well, despite evidence that HLA-DQ genotype influences the response to several bacterial antigens. Our study attempts to characterize and analyse the behaviour of HLA-DQ after trauma in patients with and without infection. Twenty-five patients were studied following major injury. Fifteen of the 25 patients developed infection (men = 11, women = 4); 10 patients developed no infection (men = 9, women = 1). The mean age was 34 +/- 12 years for patients with no infection and 52 +/- 20 years for those with infection. Monocyte HLA-DQ surface expression was determined using FITC-labelled antibodies and flow cytometry. Expression was compared with a control population of 11 healthy volunteers. The percentage of monocytes expressing HLA-DQ following trauma was reduced in patients with infection and in those without infection, but returned to normal (days 8-14) only in those patients who did not develop infection. Monocyte HLA-DQ mean channel fluorescence was reduced on day 1, but quickly returned to normal in those patients who subsequently developed infection. Stimulated with lipopolysaccharide, the initial samples of 13 patients who developed infection showed that surface expression on these monocytes could be elevated into the normal range. We conclude that HLA-DQ is an additional early marker of outcome that may not function merely as an immune suppressor. The maintained ability of HLA-DQ to present self-antigens may be important in the initial stages of the host response to injury.
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Affiliation(s)
- J V Taylor
- Department of Surgery, Price Institute of Surgical Research, University of Louisville School of Medicine, Louisville, KY 40292, USA
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36
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Kimmel SG, Ohbatake M, Kushida M, Merguerian P, Clarke ID, Kim PC. Murine xenogeneic immune responses to the human testis: a presumed immune-privileged tissue. Transplantation 2000; 69:1075-84. [PMID: 10762210 DOI: 10.1097/00007890-200003270-00010] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Immune privilege provides a natural paradigm for potentially down-regulating allogeneic and xenogeneic inflammatory immune responses. Fas ligand has been suggested as a general underlying mechanism of immune privilege; the human Fas ligand has been shown to ligate murine Fas in vitro. METHODS In this study, we examined whether the human testicular xenograft, a presumed immune-privileged tissue would have prolonged survival in mice. In addition, in vitro and in vivo murine xenogeneic immune responses to the human testicular xenografts were characterized using MHC class I, MHC class II, CD4, CD8, CD4/8 knockout mice. RESULTS Unlike in rodent testis, Fas ligand mRNA is not expressed and Fas is highly expressed in human testis. Human testicular xenografts are immunogenic, and do not induce any preferential pattern of recipient systemic Th1 or Th2 cytokine bias. Interestingly, an indefinite survival of the human testicular xenografts is observed in murine MHC class II knockout mice, whereas the human skin xenografts were rejected without a delay. In vivo murine immune responses to human testicular xenografts require a recipient MHC class II-dependent CD4 T cell-mediated process that appears to depend on B7-1/B7-2 costimulatory signals. CONCLUSIONS Our results demonstrate that the concept of immune privilege, as defined by the expression of Fas ligand and prolonged survival after transplantation, cannot be extended to human testis. The stringent restriction of murine xenogeneic immune responses to discordant human testicular xenografts to the indirect MHC class II-dependent CD4 T cell-mediated pathway suggests a potential venue for immune modulation to induce tolerance across a discordant species barrier.
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Affiliation(s)
- S G Kimmel
- Department of Surgery, The Hospital for Sick Children and The University of Toronto, Ontario, Canada
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37
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Yuan L, Lowell GH, Hoover DL, Colleton CA, Hammack CA, Young LD, Fischer R, Patchen ML, Cross AS. Kinetics of cellular and cytokine responses in a chimeric mouse model for the study of staphylococcal enterotoxin B pathogenesis. Immunol Lett 2000; 71:19-26. [PMID: 10709781 DOI: 10.1016/s0165-2478(99)00158-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The mechanisms by which superantigens, such as staphylococcal enterotoxin B (SEB), contribute to microbial pathogenicity have been poorly defined. The study of such pathogenic processes has been hampered by the lack of an adequate animal model. We utilized a previously described murine chimeric model to determine the cytokines and cell populations that might be involved in SEB toxicity. In the absence of bone marrow transplantation (BMT), all total body irradiated (TBI) mice died, while all transplanted mice survived up to 6 months. Compared with non-TBI and non-BMT mice, chimeric mice had an increased percentage of CD11b (Mac-1)-positive splenocytes (17 vs. 59%, P < 0.05) and decreased CD45R-positive (B) cells (33 vs. 6%, P < 0.05) at 6 weeks after BMT. The relative numbers of splenocyte CD4 and CD8 cells were similar in chimeric and normal mice. Susceptibility of chimeric animals to 10 or 100 microg SEB was time-dependent: no mice challenged at 2 weeks post-BMT died, but 15% of mice challenged at 4 weeks and 50% of those challenged at 6-8 weeks died. Compared with TBI and non-BMT C3H/HeJ mice, SEB-challenged chimeric mice at 6-8 weeks had (1) increased splenocyte mRNA expression for: IFN-gamma (3.5 x optimally at 1 h), TNF-alpha (6.5 x at 2 h), IL-6 (4.8 x at 4 h), IL-1beta (8.4 x at 4 h), IL-2 (4.7 x at 4 h), and IL-10 (3 x at 16 h), and (2) increased and earlier peak serum levels of IFN-gamma, IL-6, IL-1beta and IL-2, but no increase in serum TNF-alpha or IL-4. These data support the hypothesis that the decreased percentage of B cells and increased macrophages in chimeric mice lead to enhanced T cell-macrophage interactions after SEB administration and a lethal burst of T cell and macrophage cytokine release. This model will provide insight into cell populations and mechanisms that mediate superantigen-induced toxicity.
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Affiliation(s)
- L Yuan
- Department of Bacterial Diseases, Walter Reed Army Institute of Research, Washington, DC 20307-5100, USA
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38
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Yan Z, Yang DC, Neill R, Jett M. Production of tumor necrosis factor alpha in human T lymphocytes by staphylococcal enterotoxin B correlates with toxin-induced proliferation and is regulated through protein kinase C. Infect Immun 1999; 67:6611-8. [PMID: 10569782 PMCID: PMC97074 DOI: 10.1128/iai.67.12.6611-6618.1999] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/1999] [Accepted: 08/16/1999] [Indexed: 11/20/2022] Open
Abstract
The superantigen staphylococcal enterotoxin B (SEB) simultaneously binds both the major histocompatibility complex (MHC) class II receptor on monocytes and the T-cell receptor (TCR) on T lymphocytes, resulting in a range of cell responses including induction of tumor necrosis factor alpha (TNF-alpha). In this study, we have used mixed cultures of human peripheral blood monocytes and lymphocytes to investigate biochemical events controlling SEB induction of TNF-alpha. TNF-alpha production induced by SEB in mixed cultures is more closely associated with T cells than with monocytes: (i) a TCR-binding-site mutant of SEB (N23F) is less active in TNF-alpha induction than an MHC class II receptor-binding-site mutant (F44R), and (ii) flow cytometric analysis indicated that SEB induced TNF-alpha production in T cells but not in monocytes. Pretreatment of cells with inhibitors of signal transduction pathways was employed to further define events in SEB-induced TNF-alpha production. Neither protein kinase A inhibitors nor two protein tyrosine kinase inhibitors altered SEB-induced TNF-alpha production. In contrast, SEB induced protein kinase C (PKC) translocation, and pretreatment of cultures with inhibitors of PKC blocked TNF-alpha induction. Alteration of levels of diacylglycerol (DAG), an activator of PKC, by treatment with inhibitors of phospholipase C or DAG kinase also altered SEB-induced TNF-alpha production. These data suggest that PKC activation plays a critical role in SEB-induced TNF-alpha production in human T cells.
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Affiliation(s)
- Z Yan
- Chemistry Department, Georgetown University, Washington, D.C. 20056, USA
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39
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Hall FC, Cope AP, Patel SD, Sønderstrup G. Isolating the molecular suspect: HLA transgenic mice in the study of human autoimmune disease. Rheumatology (Oxford) 1999; 38:697-704. [PMID: 10501414 DOI: 10.1093/rheumatology/38.8.697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- F C Hall
- D345 Fairchild Building, Department of Microbiology and Immunology, Stanford, CA 94305, USA
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40
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41
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Burke B. 4.3 Transgenic and Knockout Animals in the Study of Bacterial Pathogenesis. J Microbiol Methods 1998. [DOI: 10.1016/s0580-9517(08)70272-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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42
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Florquin S, Aaldering L. Superantigens: a tool to gain new insight into cellular immunity. RESEARCH IN IMMUNOLOGY 1997; 148:373-86. [PMID: 9443577 DOI: 10.1016/s0923-2494(97)82871-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- S Florquin
- Department of Pathology, Leiden University, The Netherlands
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43
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Hansson J, Ohlsson L, Persson R, Andersson G, Ilbäck NG, Litton MJ, Kalland T, Dohlsten M. Genetically engineered superantigens as tolerable antitumor agents. Proc Natl Acad Sci U S A 1997; 94:2489-94. [PMID: 9122222 PMCID: PMC20115 DOI: 10.1073/pnas.94.6.2489] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/1996] [Accepted: 12/03/1996] [Indexed: 02/04/2023] Open
Abstract
Superantigens (SAg) are a family of bacterial and viral proteins with strong immunostimulatory properties. SAg bound to major histocompatibility complex (MHC) class II molecules activate a high frequency of T cells and represent the most potent known activators of T cells to date. To explore the use of SAg for T cell-based tumor therapy we have created a tumor-reactive SAg by engineering a fusion protein composed of a tumor-reactive mAb (C215Fab) and the bacterial SAg staphylococcal enterotoxin A (SEA). A point mutation D227A was introduced at the major MHC class II binding site in SEA to reduce systemic toxicity. Treatment of tumor bearing mice with the Fab-SEA D227A fusion protein resulted in profound antitumor effects with a markedly reduced toxicity as compared with the wild-type Fab-SEA fusion protein. The reduced toxicity was probably due to a weak distribution of the SEA D227A fusion protein in tissues with a high MHC class II expression and low systemic cytokine levels as exhibited in mice and rabbits. The data presented demonstrate the efficacy of immunoconjugates containing a mutated SAg in directing a T cell attack against tumor cells with minimal systemic immune activation.
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MESH Headings
- Animals
- Antibodies, Monoclonal
- Binding Sites
- Cloning, Molecular
- Cytokines/blood
- Enterotoxins/pharmacokinetics
- Enterotoxins/therapeutic use
- Enterotoxins/toxicity
- Genetic Engineering/methods
- Histocompatibility Antigens Class II/metabolism
- Humans
- Immunoglobulin Fab Fragments
- Immunotoxins/pharmacokinetics
- Immunotoxins/therapeutic use
- Immunotoxins/toxicity
- Lung Neoplasms/immunology
- Lung Neoplasms/pathology
- Lung Neoplasms/secondary
- Lung Neoplasms/therapy
- Lymphocytes/immunology
- Lymphocytes/pathology
- Melanoma, Experimental/immunology
- Melanoma, Experimental/pathology
- Melanoma, Experimental/secondary
- Melanoma, Experimental/therapy
- Mice
- Mice, Transgenic
- Point Mutation
- Rabbits
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Recombinant Fusion Proteins/pharmacokinetics
- Recombinant Fusion Proteins/therapeutic use
- Recombinant Fusion Proteins/toxicity
- Recombinant Proteins/biosynthesis
- Spleen/immunology
- Spleen/pathology
- Staphylococcus aureus
- Superantigens/therapeutic use
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Affiliation(s)
- J Hansson
- Lund Research Center, Pharmacia & Upjohn, Sweden
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