1
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Zhao G, Xie Y, Lei X, Guo R, Cui N. mTOR aggravated CD4 + T cell pyroptosis by regulating the PPARγ-Nrf2 pathway in sepsis. Int Immunopharmacol 2024; 140:112822. [PMID: 39096877 DOI: 10.1016/j.intimp.2024.112822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 07/15/2024] [Accepted: 07/25/2024] [Indexed: 08/05/2024]
Abstract
Sepsis is a systemic inflammatory response syndrome caused by a dysregulated host response to infection. CD4+T cell reduction is crucial to sepsis-induced immunosuppression. Pyroptosis, a programmed necrosis, is concerned with lymphocytopenia. Peroxisome proliferator-activated receptor gamma (PPARγ) regulated by upstream mTOR, exerts anti-pyroptosis effects. To investigate the potential effects of mTOR-PPARγ on sepsis-induced CD4+T cell depletion and the underlying mechanisms, we observed mTOR activation and pyroptosis with PPARγ-Nrf suppression through cecal ligation and puncture (CLP) sepsis mouse model. Further mechanism research used genetically modified mice with T cell-specific knockout mTOR or Tuberous Sclerosis Complex1 (TSC1). It revealed that mTOR mediated CD4 + T cell pyroptosis in septic mice by negatively regulating the PPARγ-Nrf2 signaling pathway. Taken together, mTOR-PPARγ-Nrf2 signaling mediated the CD4+ T cell pyroptosis in sepsis, contributing to CD4+T cell depletion and immunosuppression.
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Affiliation(s)
- Guoyu Zhao
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100730, China
| | - Yawen Xie
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100730, China
| | - Xianli Lei
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100730, China
| | - Ran Guo
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100730, China
| | - Na Cui
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100730, China.
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2
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Assis PA, Allen RM, Schaller MA, Kunkel SL, Bermick JR. Metabolic reprogramming and dysregulated IL-17 production impairs CD4 T cell function post sepsis. iScience 2024; 27:110114. [PMID: 39015145 PMCID: PMC11251092 DOI: 10.1016/j.isci.2024.110114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/05/2023] [Accepted: 05/23/2024] [Indexed: 07/18/2024] Open
Abstract
Sepsis survivors are at high risk for infection-related rehospitalization and mortality for years following the resolution of the acute septic event. These infection-causing microorganisms generally do not cause disease in immunocompetent hosts, suggesting that the post-septic immune response is compromised. Given the importance of CD4 T cells in the development of long-lasting protective immunity, we analyzed their post-septic function. Here we showed that sepsis induced chronic increased and non-specific production of IL-17 by CD4 T cells, resulting in the inability to mount an effective immune response to a secondary pneumonia challenge. Altered cell function was associated with metabolic reprogramming, characterized by mitochondrial dysfunction and increased glycolysis. This metabolic reprogramming began during the acute septic event and persisted long after sepsis had resolved. Our findings reveal cell metabolism as a potential therapeutic target. Given the critical role of cell metabolism in the physiological and pathophysiological processes of immune cells, these findings reveal a potential new therapeutic target to help mitigate sepsis survivors' susceptibility to secondary infections.
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Affiliation(s)
- Patricia A. Assis
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Ronald M. Allen
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Matthew A. Schaller
- Division of Pulmonary, Critical Care & Sleep Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Steven L. Kunkel
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jennifer R. Bermick
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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3
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Shan J, Shi R, Hazra R, Hu X. Regulatory T lymphocytes in traumatic brain injury. Neurochem Int 2024; 173:105660. [PMID: 38151109 PMCID: PMC10872294 DOI: 10.1016/j.neuint.2023.105660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 12/29/2023]
Abstract
Traumatic brain injury (TBI) presents a significant global health challenge with no effective therapies developed to date. Regulatory T lymphocytes (Tregs) have recently emerged as a potential therapy due to their critical roles in maintaining immune homeostasis, reducing inflammation, and promoting brain repair. Following TBI, fluctuations in Treg populations and shifts in their functionality have been noted. However, the precise impact of Tregs on the pathophysiology of TBI remains unclear. In this review, we discuss recent advances in understanding the intricate roles of Tregs in TBI and other brain diseases. Increased knowledge about Tregs may facilitate their future application as an immunotherapy target for TBI treatment.
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Affiliation(s)
- Jiajing Shan
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, 15261, USA; Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Ruyu Shi
- Department of Human Genetics, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Rimi Hazra
- Department of Medicine, Pittsburgh Heart Lung and Blood Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
| | - Xiaoming Hu
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, 15261, USA; Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
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4
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Sonobe S, Kitabatake M, Hara A, Konda M, Ouji-Sageshima N, Terada-Ikeda C, Furukawa R, Imakita N, Oda A, Takeda M, Takamura S, Inoue S, Kunkel SL, Kawaguchi M, Ito T. THE CRITICAL ROLE OF THE HISTONE MODIFICATION ENZYME SETDB2 IN THE PATHOGENESIS OF ACUTE RESPIRATORY DISTRESS SYNDROME. Shock 2023; 60:137-145. [PMID: 37195726 PMCID: PMC10417228 DOI: 10.1097/shk.0000000000002145] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 05/03/2023] [Indexed: 05/18/2023]
Abstract
ABSTRACT Introduction: Acute respiratory distress syndrome (ARDS) is a severe hypoxemic respiratory failure with a high in-hospital mortality. However, the molecular mechanisms underlying ARDS remain unclear. Recent findings have indicated that the onset of severe inflammatory diseases, such as sepsis, is regulated by epigenetic changes. We investigated the role of epigenetic changes in ARDS pathogenesis using mouse models and human samples. Methods: Acute respiratory distress syndrome was induced in a mouse model (C57BL/6 mice, myeloid cell or vascular endothelial cell [VEC]-specific SET domain bifurcated 2 [Setdb2]-deficient mice [Setdb2 ff Lyz2 Cre+ or Setdb2 ff Tie2 Cre+ ], and Cre - littermates) by intratracheal administration of lipopolysaccharide (LPS). Analyses were performed at 6 and 72 h after LPS administration. Sera and lung autopsy specimens from ARDS patients were examined. Results: In the murine ARDS model, we observed high expression of the histone modification enzyme SET domain bifurcated 2 ( Setdb2 ) in the lungs. In situ hybridization examination of the lungs revealed Setdb2 expression in macrophages and VECs. The histological score and albumin level of bronchoalveolar lavage fluid were significantly increased in Setdb2 ff Tie2 Cre+ mice following LPS administration compared with Setdb2 ff Tie2 Cre- mice, whereas there was no significant difference between the control and Setdb2 ff Lyz2 Cre+ mice. Apoptosis of VECs was enhanced in Setdb2 ff Tie2 Cre+ mice. Among the 84 apoptosis-related genes, the expression of TNF receptor superfamily member 10b ( Tnfrsf10b ) was significantly higher in Setdb2 ff Tie2 Cre+ mice than in control mice. Acute respiratory distress syndrome patients' serum showed higher SETDB2 levels than those of healthy volunteers. SETDB2 levels were negatively correlated with the partial pressure of oxygen in arterial blood/fraction of inspiratory oxygen concentration ratio. Conclusion: Acute respiratory distress syndrome elevates Setdb2 , apoptosis of VECs, and vascular permeability. Elevation of histone methyltransferase Setdb2 suggests the possibility to histone change and epigenetic modification. Thus, Setdb2 may be a novel therapeutic target for controlling the pathogenesis of ARDS.
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Affiliation(s)
- Shota Sonobe
- Department of Immunology, Nara Medical University, Kashihara, Japan
- Department of Anesthesiology, Nara Medical University, Kashihara, Japan
| | | | - Atsushi Hara
- Department of Immunology, Nara Medical University, Kashihara, Japan
| | - Makiko Konda
- Department of Immunology, Nara Medical University, Kashihara, Japan
- Department of Anesthesiology, Nara Medical University, Kashihara, Japan
| | | | | | - Ryutaro Furukawa
- Department of Immunology, Nara Medical University, Kashihara, Japan
- Center for Infectious Diseases, Nara Medical University, Kashihara, Japan
| | - Natsuko Imakita
- Department of Immunology, Nara Medical University, Kashihara, Japan
- Center for Infectious Diseases, Nara Medical University, Kashihara, Japan
| | - Akihisa Oda
- Department of Pediatrics, Nara Medical University, Kashihara, Japan
| | - Maiko Takeda
- Department of Diagnostic Pathology, Nara Medical University, Kashihara, Japan
| | - Shiki Takamura
- Laboratory for Immunological Memory, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
| | - Satoki Inoue
- Department of Anesthesiology, Fukushima Medical University, Fukushima, Japan
| | - Steven L. Kunkel
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | | | - Toshihiro Ito
- Department of Immunology, Nara Medical University, Kashihara, Japan
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5
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Wu D, Shi Y, Zhang H, Miao C. Epigenetic mechanisms of Immune remodeling in sepsis: targeting histone modification. Cell Death Dis 2023; 14:112. [PMID: 36774341 PMCID: PMC9922301 DOI: 10.1038/s41419-023-05656-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/01/2023] [Accepted: 02/03/2023] [Indexed: 02/13/2023]
Abstract
Sepsis is a life-threatening disorder disease defined as infection-induced dysregulated immune responses and multiple organ dysfunction. The imbalance between hyperinflammation and immunosuppression is a crucial feature of sepsis immunity. Epigenetic modifications, including histone modifications, DNA methylation, chromatin remodeling, and non-coding RNA, play essential roles in regulating sepsis immunity through epi-information independent of the DNA sequence. In recent years, the mechanisms of histone modification in sepsis have received increasing attention, with ongoing discoveries of novel types of histone modifications. Due to the capacity for prolonged effects on immune cells, histone modifications can induce immune cell reprogramming and participate in the long-term immunosuppressed state of sepsis. Herein, we systematically review current mechanisms of histone modifications involved in the regulation of sepsis, summarize their role in sepsis from an immune perspective and provide potential therapeutic opportunities targeting histone modifications in sepsis treatment.
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Affiliation(s)
- Dan Wu
- Department of Anesthesiology, Zhongshan Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Perioperative Stress and Protection, Shanghai, China
- Department of Anesthesiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yuxin Shi
- Department of Anesthesiology, Zhongshan Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Perioperative Stress and Protection, Shanghai, China
- Department of Anesthesiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Hao Zhang
- Department of Anesthesiology, Zhongshan Hospital, Fudan University, Shanghai, China.
- Shanghai Key Laboratory of Perioperative Stress and Protection, Shanghai, China.
- Department of Anesthesiology, Shanghai Medical College, Fudan University, Shanghai, China.
| | - Changhong Miao
- Department of Anesthesiology, Zhongshan Hospital, Fudan University, Shanghai, China.
- Shanghai Key Laboratory of Perioperative Stress and Protection, Shanghai, China.
- Department of Anesthesiology, Shanghai Medical College, Fudan University, Shanghai, China.
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6
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Yao RQ, Ren C, Zheng LY, Xia ZF, Yao YM. Advances in Immune Monitoring Approaches for Sepsis-Induced Immunosuppression. Front Immunol 2022; 13:891024. [PMID: 35619710 PMCID: PMC9127053 DOI: 10.3389/fimmu.2022.891024] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 03/29/2022] [Indexed: 12/29/2022] Open
Abstract
Sepsis represents a life-threatening organ dysfunction due to an aberrant host response. Of note is that majority of patients have experienced a severe immune depression during and after sepsis, which is significantly correlated with the occurrence of nosocomial infection and higher risk of in-hospital death. Nevertheless, the clinical sign of sepsis-induced immune paralysis remains highly indetectable and ambiguous. Given that, specific yet robust biomarkers for monitoring the immune functional status of septic patients are of prominent significance in clinical practice. In turn, the stratification of a subgroup of septic patients with an immunosuppressive state will greatly contribute to the implementation of personalized adjuvant immunotherapy. In this review, we comprehensively summarize the mechanism of sepsis-associated immunosuppression at the cellular level and highlight the recent advances in immune monitoring approaches targeting the functional status of both innate and adaptive immune responses.
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Affiliation(s)
- Ren-Qi Yao
- Translational Medicine Research Center, Medical Innovation Research Division and Fourth Medical Center of the Chinese People's Liberation Army (PLA) General Hospital, Beijing, China.,Department of Burn Surgery, The First Affiliated Hospital of Naval Medical University, Shanghai, China
| | - Chao Ren
- Translational Medicine Research Center, Medical Innovation Research Division and Fourth Medical Center of the Chinese People's Liberation Army (PLA) General Hospital, Beijing, China.,Department of Pulmonary and Critical Care Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Li-Yu Zheng
- Translational Medicine Research Center, Medical Innovation Research Division and Fourth Medical Center of the Chinese People's Liberation Army (PLA) General Hospital, Beijing, China
| | - Zhao-Fan Xia
- Department of Burn Surgery, The First Affiliated Hospital of Naval Medical University, Shanghai, China
| | - Yong-Ming Yao
- Translational Medicine Research Center, Medical Innovation Research Division and Fourth Medical Center of the Chinese People's Liberation Army (PLA) General Hospital, Beijing, China
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7
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Abstract
Sepsis is expected to have a substantial impact on public health and cost as its prevalence increases. Factors contributing to increased prevalence include a progressively aging population, advances in the use of immunomodulatory agents to treat a rising number of diseases, and immune-suppressing therapies in organ transplant recipients and cancer patients. It is now recognized that sepsis is associated with profound and sustained immunosuppression, which has been implicated as a predisposing factor in the increased susceptibility of patients to secondary infections and mortality. In this review, we discuss mechanisms of sepsis-induced immunosuppression and biomarkers that identify a state of impaired immunity. We also highlight immune-enhancing strategies that have been evaluated in patients with sepsis, as well as therapeutics under current investigation. Finally, we describe future challenges and the need for a new treatment paradigm, integrating predictive enrichment with patient factors that may guide the future selection of tailored immunotherapy. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Lisa K Torres
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, New York-Presbyterian Hospital-Weill Cornell Medicine, New York, NY, USA;
| | - Peter Pickkers
- Department of Intensive Care Medicine, Radboud University Medical Center, Nijmegen, The Netherlands;
| | - Tom van der Poll
- Center of Experimental and Molecular Medicine, Division of Infectious Diseases, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands;
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8
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Miljković Đ, Stanisavljević S, Jensen IJ, Griffith TS, Badovinac VP. Sepsis and multiple sclerosis: Causative links and outcomes. Immunol Lett 2021; 238:40-46. [PMID: 34320384 DOI: 10.1016/j.imlet.2021.07.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 06/08/2021] [Accepted: 07/21/2021] [Indexed: 10/20/2022]
Abstract
Sepsis is a life-threatening condition characterized by an acute cytokine storm followed by prolonged dysfunction of the immune system in the survivors. Post-septic lymphopenia and functional deficits of the remaining immune cells lead to increased susceptibility to secondary infections and other morbid conditions causing late death in the patients. This state of post-septic immunoparalysis may also influence disorders stemming from inappropriate or overactive immune responses, such as autoimmune and immunoinflammatory diseases, including multiple sclerosis. In addition, ongoing autoimmunity likely influences the susceptibility to and outcome of sepsis. This review article addresses the bidirectional relationship between sepsis and multiple sclerosis, with a focus on the immunologic mechanisms of the interaction and potential directions for future studies.
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Affiliation(s)
- Đorđe Miljković
- Department of Immunology, Institute for Biological Research "Siniša Stanković" - National Institute of Republic of Serbia, University of Belgrade, 11000 Belgrade, Serbia.
| | - Suzana Stanisavljević
- Department of Immunology, Institute for Biological Research "Siniša Stanković" - National Institute of Republic of Serbia, University of Belgrade, 11000 Belgrade, Serbia
| | - Isaac J Jensen
- Department of Pathology, Department of Microbiology and Immunology, Interdisciplinary Program in Immunology, University of Iowa, Iowa City, IA 52242, USA
| | - Thomas S Griffith
- Microbiology, Immunology, and Cancer Biology PhD Program, Department of Urology, Center for Immunology, Masonic Cancer Center, University of Minnesota, Minneapolis VA Health Care System, Minneapolis, MN 55417, USA
| | - Vladimir P Badovinac
- Department of Pathology, Department of Microbiology and Immunology, Interdisciplinary Program in Immunology, University of Iowa, Iowa City, IA 52242, USA
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9
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Gaborit BJ, Chaumette T, Chauveau M, Asquier-Khati A, Roquilly A, Boutoille D, Josien R, Salomon BL, Asehnoune K. Circulating Treg cells expressing TNF receptor type 2 contributes to sepsis-induced immunosuppression in patients during sepsis shock. J Infect Dis 2021; 224:2160-2169. [PMID: 34019653 DOI: 10.1093/infdis/jiab276] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 05/17/2021] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Septic shock remains a major cause of death that can be complicated by a long-term impairment in immune function defining immunosuppression induced by sepsis (IS). Among Treg cells, the tumor necrosis factor receptor 2 positive (TNFR2 pos) Treg cell subset endorses significant immunosuppressive functions in human tumors and in a sepsis mouse model but have not been investigated during septic shock in humans. METHODS We prospectively enrolled patients with septic shock hospitalized in Intensive Care Unit (ICU). We performed immunophenotyping and functional tests of CD4+T cells, Treg cells and TNFR2 posTregcells, on blood samples collected at 1, 4 and 7 days after admission in ICU. RESULTS We investigated 10 patients with septic shock and compared to 10 healthy controls. Although the proportions of circulating Tregcells and TNFR2 posTregcells subsets were not increased, their CTLA-4 expression and suppressive functions in vitro were increased at 4 days of septic shock. Also, PBMC from healthy donors cultured with serum from septic shock patients had increased CTLA4 expression in TNFR2 pos Treg cells compared to TNFR2 neg Treg cells. CONCLUSION In patients with septic shock, CTLA-4 expression and suppressive function were increased in circulating TNFR2 posTreg cells. We identify TNFR2 posTreg cells as a potential attractive target for therapeutic intervention.
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Affiliation(s)
- Benjamin Jean Gaborit
- Nantes Université, Thérapeutiques Anti-Infectieuses, Nantes, France.,CHU Nantes, Department of Infectious Diseases.,CHU Nantes, INSERM, CIC, Nantes, France
| | - Tanguy Chaumette
- Nantes Université, Thérapeutiques Anti-Infectieuses, Nantes, France
| | - Marie Chauveau
- Nantes Université, Thérapeutiques Anti-Infectieuses, Nantes, France.,CHU Nantes, Department of Infectious Diseases.,CHU Nantes, INSERM, CIC, Nantes, France
| | - Antoine Asquier-Khati
- Nantes Université, Thérapeutiques Anti-Infectieuses, Nantes, France.,CHU Nantes, Department of Infectious Diseases.,CHU Nantes, INSERM, CIC, Nantes, France
| | - Antoine Roquilly
- Nantes Université, Thérapeutiques Anti-Infectieuses, Nantes, France.,CHU Nantes, Surgical Intensive Care Unit, Nantes, France
| | - David Boutoille
- Nantes Université, Thérapeutiques Anti-Infectieuses, Nantes, France.,CHU Nantes, Department of Infectious Diseases.,CHU Nantes, INSERM, CIC, Nantes, France
| | - Régis Josien
- Nantes Université, INSERM, Centre de Recherche en Transplantation et Immunologie UMR 1064, ITUN, Nantes, France.,CHU Nantes, Laboratoire d'Immunologie, CIMNA, Nantes, France
| | - Benoit L Salomon
- Sorbonne Université, INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France
| | - Karim Asehnoune
- Nantes Université, Thérapeutiques Anti-Infectieuses, Nantes, France.,CHU Nantes, Surgical Intensive Care Unit, Nantes, France
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10
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He W, Xiao K, Fang M, Xie L. Immune Cell Number, Phenotype, and Function in the Elderly with Sepsis. Aging Dis 2021; 12:277-296. [PMID: 33532141 PMCID: PMC7801284 DOI: 10.14336/ad.2020.0627] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 06/27/2020] [Indexed: 12/12/2022] Open
Abstract
Sepsis is a form of life-threatening organ dysfunction caused by dysregulated host responses to an infection that can be partly attributed to immune dysfunction. Although sepsis affects patients of all ages, elderly individuals display increased susceptibility and mortality. This is partly due to immunosenescence, a decline in normal immune system function associated with physiological aging that affects almost all cell types in the innate and adaptive immune systems. In elderly patients with sepsis, these alterations in immune cells such as endothelial cells, neutrophils, monocytes, macrophages, natural killer cells, dendritic cells, T lymphocytes, and B lymphocytes, are largely responsible for their poor prognosis and increased mortality. Here, we review recent studies investigating the events affecting both innate and adaptive immune cells in elderly mice and patients with sepsis, including alterations in their number, phenotype, and function, to shed light on possible new therapeutic strategies.
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Affiliation(s)
- Wanxue He
- College of Pulmonary and Critical Care Medicine, Chinese PLA General Hospital, Beijing, China.
| | - Kun Xiao
- College of Pulmonary and Critical Care Medicine, Chinese PLA General Hospital, Beijing, China.
| | - Min Fang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
| | - Lixin Xie
- College of Pulmonary and Critical Care Medicine, Chinese PLA General Hospital, Beijing, China.
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11
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Zhao D, Li Z, Liu X, Liu N, Bao X, Sun H, Meng Q, Ren H, Bai J, Zhou X, Tang L. Lymphocyte expression of EZH2 is associated with mortality and secondary infectious complications in sepsis. Int Immunopharmacol 2020; 89:107042. [PMID: 33068867 DOI: 10.1016/j.intimp.2020.107042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 09/20/2020] [Accepted: 09/22/2020] [Indexed: 12/25/2022]
Abstract
Recent studies have shown that epigenetic factors may affect immune responses. We previously reported that histone methyltransferase enhancer of zeste homolog 2 (EZH2) was involved in the innate inflammatory responses both in animal model of sepsis and in septic patients. In this study, we prospectively evaluated EZH2 expression kinetics in peripheral CD4+ and CD8+ T cells and HLA-DR expression in CD14+ cells from 48 patients with sepsis and 48 healthy controls. Results showed higher level of EZH2 in CD4+ T cells and CD8+ T cells in sepsis patients than in controls. Meanwhile, EZH2 expression was correlated with CD27 status on T cells. Mean fluorescence intensity (MFI) of EZH2 in CD8+ T cells on day 1 independently predicted death in septic patients. Also, the combination of CD8+ T cell EZH2 expression with APACHEII and SOFA score could enhance the prognostic predictive ability. Moreover, multivariate logistic regression analysis showed that increased expression (proportion and MFI) of EZH2 in CD4+ and CD8+ lymphocytes on day 3 were independently associated with nosocomial infection in septic patients. Additionally, spearman correlation analysis indicated that the levels of EZH2 in CD4+ T cells and CD8+ T cells correlated to CD14+ cells-expressing HLA-DR in patients with sepsis at each time point. Overall, these findings suggest that EZH2 in CD4+ T cells or/and CD8+ T cells may be a novel biomarker for predicting adverse outcomes (mortality and secondary infectious complications) in patients with sepsis.
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Affiliation(s)
- Dongyang Zhao
- Department of Internal Emergency Medicine and Critical Care, Shanghai East Hospital, Tong Ji University, Shanghai 200120, China
| | - Zhe Li
- Department of Internal Emergency Medicine and Critical Care, Shanghai East Hospital, Tong Ji University, Shanghai 200120, China; Medical School/Tongji University, Shanghai 200120, China
| | - Xiandong Liu
- Department of Internal Emergency Medicine and Critical Care, Shanghai East Hospital, Tong Ji University, Shanghai 200120, China
| | - Na Liu
- Department of Nephrology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Xiaowei Bao
- Department of Internal Emergency Medicine and Critical Care, Shanghai East Hospital, Tong Ji University, Shanghai 200120, China
| | - Hong Sun
- Department of Internal Emergency Medicine and Critical Care, Shanghai East Hospital, Tong Ji University, Shanghai 200120, China
| | - Qinshu Meng
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University, Shanghai 200120, China
| | - Huijuan Ren
- Department of Internal Emergency Medicine and Critical Care, Shanghai East Hospital, Tong Ji University, Shanghai 200120, China
| | - Jianwen Bai
- Department of Internal Emergency Medicine and Critical Care, Shanghai East Hospital, Tong Ji University, Shanghai 200120, China
| | - Xiaohui Zhou
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University, Shanghai 200120, China.
| | - Lunxian Tang
- Department of Internal Emergency Medicine and Critical Care, Shanghai East Hospital, Tong Ji University, Shanghai 200120, China.
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12
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van der Slikke EC, An AY, Hancock REW, Bouma HR. Exploring the pathophysiology of post-sepsis syndrome to identify therapeutic opportunities. EBioMedicine 2020; 61:103044. [PMID: 33039713 PMCID: PMC7544455 DOI: 10.1016/j.ebiom.2020.103044] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/09/2020] [Accepted: 09/16/2020] [Indexed: 12/14/2022] Open
Abstract
Sepsis is a major health problem worldwide. As the number of sepsis cases increases, so does the number of sepsis survivors who suffer from “post-sepsis syndrome” after hospital discharge. This syndrome involves deficits in multiple systems, including the immune, cognitive, psychiatric, cardiovascular, and renal systems. Combined, these detrimental consequences lead to rehospitalizations, poorer quality of life, and increased mortality. Understanding the pathophysiology of these issues is crucial to develop new therapeutic opportunities to improve survival rate and quality of life of sepsis survivors. Such novel strategies include modulating the immune system and addressing mitochondrial dysfunction. A sepsis follow-up clinic may be useful to identify long-term health issues associated with post-sepsis syndrome and evaluate existing and novel strategies to improve the lives of sepsis survivors.
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Affiliation(s)
- Elisabeth C van der Slikke
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, , P.O. Box 30.001, EB70, 9700 RB, Groningen, The Netherlands
| | - Andy Y An
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Hjalmar R Bouma
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, , P.O. Box 30.001, EB70, 9700 RB, Groningen, The Netherlands; Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
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13
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Martin MD, Badovinac VP, Griffith TS. CD4 T Cell Responses and the Sepsis-Induced Immunoparalysis State. Front Immunol 2020; 11:1364. [PMID: 32733454 PMCID: PMC7358556 DOI: 10.3389/fimmu.2020.01364] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/28/2020] [Indexed: 12/20/2022] Open
Abstract
Sepsis remains a major cause of death in the United States and worldwide, and costs associated with treating septic patients place a large burden on the healthcare industry. Patients who survive the acute phase of sepsis display long-term impairments in immune function due to reductions in numbers and function of many immune cell populations. This state of chronic immunoparalysis renders sepsis survivors increasingly susceptible to infection with newly or previously encountered infections. CD4 T cells play important roles in the development of cellular and humoral immune responses following infection. Understanding how sepsis impacts the CD4 T cell compartment is critical for informing efforts to develop treatments intended to restore immune system homeostasis following sepsis. This review will focus on the current understanding of how sepsis impacts the CD4 T cell responses, including numerical representation, repertoire diversity, phenotype and effector functionality, subset representation (e.g., Th1 and Treg frequency), and therapeutic efforts to restore CD4 T cell numbers and function following sepsis. Additionally, we will discuss recent efforts to model the acute sepsis phase and resulting immune dysfunction using mice that have previously encountered infection, which more accurately reflects the immune system of humans with a history of repeated infection throughout life. A thorough understanding of how sepsis impacts CD4 T cells based on previous studies and new models that accurately reflect the human immune system may improve translational value of research aimed at restoring CD4 T cell-mediated immunity, and overall immune fitness following sepsis.
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Affiliation(s)
- Matthew D. Martin
- Department of Urology, University of Minnesota, Minneapolis, MN, United States
| | - Vladimir P. Badovinac
- Department of Pathology, University of Iowa, Iowa City, IA, United States
- Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA, United States
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, United States
| | - Thomas S. Griffith
- Department of Urology, University of Minnesota, Minneapolis, MN, United States
- Microbiology, Immunology, and Cancer Biology PhD Program, University of Minnesota, Minneapolis, MN, United States
- Center for Immunology, University of Minnesota, Minneapolis, MN, United States
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, United States
- Minneapolis VA Healthcare System, Minneapolis, MN, United States
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14
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Beltrán-García J, Osca-Verdegal R, Romá-Mateo C, Carbonell N, Ferreres J, Rodríguez M, Mulet S, García-López E, Pallardó FV, García-Giménez JL. Epigenetic biomarkers for human sepsis and septic shock: insights from immunosuppression. Epigenomics 2020; 12:617-646. [PMID: 32396480 DOI: 10.2217/epi-2019-0329] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Sepsis is a life-threatening condition that occurs when the body responds to an infection damaging its own tissues. Sepsis survivors sometimes suffer from immunosuppression increasing the risk of death. To our best knowledge, there is no 'gold standard' for defining immunosuppression except for a composite clinical end point. As the immune system is exposed to epigenetic changes during and after sepsis, research that focuses on identifying new biomarkers to detect septic patients with immunoparalysis could offer new epigenetic-based strategies to predict short- and long-term pathological events related to this life-threatening state. This review describes the most relevant epigenetic mechanisms underlying alterations in the innate and adaptive immune responses described in sepsis and septic shock, and their consequences for immunosuppression states, providing several candidates to become epigenetic biomarkers that could improve sepsis management and help predict immunosuppression in postseptic patients.
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Affiliation(s)
- Jesús Beltrán-García
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Valencia 46010, Spain.,Department of Physiology, Faculty of Medicine & Dentistry, University of Valencia, Valencia 46010, Spain.,INCLIVA Biomedical Research Institute, Valencia 46010, Spain.,EpiDisease S.L. (Spin-Off CIBER-ISCIII), Parc Científic de la Universitat de València, Paterna 46980, Valencia, Spain
| | - Rebeca Osca-Verdegal
- Department of Physiology, Faculty of Medicine & Dentistry, University of Valencia, Valencia 46010, Spain
| | - Carlos Romá-Mateo
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Valencia 46010, Spain.,Department of Physiology, Faculty of Medicine & Dentistry, University of Valencia, Valencia 46010, Spain.,INCLIVA Biomedical Research Institute, Valencia 46010, Spain
| | - Nieves Carbonell
- INCLIVA Biomedical Research Institute, Valencia 46010, Spain.,Intensive Care Unit, Clinical University Hospital of Valencia, Valencia 46010, Spain
| | - José Ferreres
- INCLIVA Biomedical Research Institute, Valencia 46010, Spain.,Intensive Care Unit, Clinical University Hospital of Valencia, Valencia 46010, Spain
| | - María Rodríguez
- INCLIVA Biomedical Research Institute, Valencia 46010, Spain.,Intensive Care Unit, Clinical University Hospital of Valencia, Valencia 46010, Spain
| | - Sandra Mulet
- INCLIVA Biomedical Research Institute, Valencia 46010, Spain.,Intensive Care Unit, Clinical University Hospital of Valencia, Valencia 46010, Spain
| | - Eva García-López
- EpiDisease S.L. (Spin-Off CIBER-ISCIII), Parc Científic de la Universitat de València, Paterna 46980, Valencia, Spain
| | - Federico V Pallardó
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Valencia 46010, Spain.,Department of Physiology, Faculty of Medicine & Dentistry, University of Valencia, Valencia 46010, Spain.,INCLIVA Biomedical Research Institute, Valencia 46010, Spain
| | - José Luis García-Giménez
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Valencia 46010, Spain.,Department of Physiology, Faculty of Medicine & Dentistry, University of Valencia, Valencia 46010, Spain.,INCLIVA Biomedical Research Institute, Valencia 46010, Spain.,EpiDisease S.L. (Spin-Off CIBER-ISCIII), Parc Científic de la Universitat de València, Paterna 46980, Valencia, Spain
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15
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Qin Y, Guo X, Yu Y, Dong S, Yan Y, Bian X, Zhao C. Screening key genes and microRNAs in sepsis by RNA-sequencing. J Chin Med Assoc 2020; 83:41-47. [PMID: 31567880 DOI: 10.1097/jcma.0000000000000209] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Sepsis is a life-threatening organ dysfunction, initiated by a dysregulated host response to infection. This study aimed to determine key genes and microRNAs (miRNAs) correlated with sepsis. METHODS Three patients with sepsis and three healthy individuals treated as controls were recruited in the current study. To identify differentially expressed mRNAs (DEmRNAs) and differentially expressed miRNAs (DEmiRNAs) between patients with sepsis and controls, RNA-sequencing and bioinformatics analysis were conducted. DEmiRNA-target DEmRNAs analysis and functional annotation of DEmiRNA-target DEmRNAs were performed. Dataset GSE46955, used to validate the expression of selected DEmRNAs, was downloaded from the Gene Expression Omnibus database. RESULTS Compared with septic patients, a total of 1199 DEmRNAs and 23 DEmiRNAs were identified. Based on DEmiRNA-target DEmRNAs analysis, hsa-miR-106b-5p (degree = 155), hsa-miR-128-3p (degree = 128), and hsa-miR-144-3p (degree = 79) were the top 3 DEmiRNAs that covered most DEmRNAs. The T cell receptor signaling pathway, pathways in cancer, FoxO signaling pathway, and influenza A were the significantly enriched Kyoto Encyclopedia of Genes and Genomes pathways of DEmiRNA-target DEmRNAs in sepsis. CONCLUSION We identified key genes and miRNAs related to sepsis. Our findings will provide new insights into understanding sepsis pathogenesis.
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Affiliation(s)
- Yanjun Qin
- Department of Emergency, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xuan Guo
- Department of Emergency, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Yueqing Yu
- Department of Clinical Laboratory, Hebei General Hospital, Shijiazhuang, China
| | - Shimin Dong
- Department of Emergency, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Yan Yan
- Department of Emergency, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xiaohua Bian
- Department of Emergency, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Caiyan Zhao
- Department of Infectious Disease, The Third Hospital of Hebei Medical University, Shijiazhuang, China
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16
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Function is Dissociated From Activation-Related Immunophenotype on Phagocytes From Patients With SIRS/Sepsis Syndrome. Shock 2019; 52:e68-e75. [DOI: 10.1097/shk.0000000000001314] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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17
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Lehnert K, Siebert U, Reißmann K, Bruhn R, McLachlan MS, Müller G, van Elk CE, Ciurkiewicz M, Baumgärtner W, Beineke A. Cytokine expression and lymphocyte proliferative capacity in diseased harbor porpoises (Phocoena phocoena) - Biomarkers for health assessment in wildlife cetaceans. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 247:783-791. [PMID: 30721869 DOI: 10.1016/j.envpol.2019.01.079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/17/2019] [Accepted: 01/19/2019] [Indexed: 06/09/2023]
Abstract
Harbor porpoises (Phocoena phocoena) in the North and Baltic Seas are exposed to anthropogenic influences including acoustic stress and environmental contaminants. In order to evaluate immune responses in healthy and diseased harbor porpoise cells, cytokine expression analyses and lymphocyte proliferation assays, together with toxicological analyses were performed in stranded and bycaught animals as well as in animals kept in permanent human care. Severely diseased harbor porpoises showed a reduced proliferative capacity of peripheral blood lymphocytes together with diminished transcription of transforming growth factor-β and tumor necrosis factor-α compared to healthy controls. Toxicological analyses revealed accumulation of polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyltrichloroethane (DDT) in harbor porpoise blood samples. Correlation analyses between blood organochlorine levels and immune parameters revealed no direct effects of xenobiotics upon lymphocyte proliferation or cytokine transcription, respectively. Results reveal an impaired function of peripheral blood leukocytes in severely diseased harbor porpoises, indicating immune exhaustion and increased disease susceptibility.
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Affiliation(s)
- Kristina Lehnert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Büsum, Germany
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Büsum, Germany
| | | | | | - Michael S McLachlan
- Baltic Sea Research Institute, Rostock, Germany; Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, Sweden
| | | | | | | | - Wolfgang Baumgärtner
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Andreas Beineke
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.
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18
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Sueyoshi K, Ledderose C, Shen Y, Lee AH, Shapiro NI, Junger WG. Lipopolysaccharide suppresses T cells by generating extracellular ATP that impairs their mitochondrial function via P2Y11 receptors. J Biol Chem 2019; 294:6283-6293. [PMID: 30787105 DOI: 10.1074/jbc.ra118.007188] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/10/2019] [Indexed: 12/20/2022] Open
Abstract
T cell suppression contributes to immune dysfunction in sepsis. However, the underlying mechanisms are not well-defined. Here, we show that exposure of human peripheral blood mononuclear cells to bacterial lipopolysaccharide (LPS) can rapidly and dose-dependently suppress interleukin-2 (IL-2) production and T cell proliferation. We also report that these effects depend on monocytes. LPS did not prevent the interaction of monocytes with T cells, nor did it induce programmed cell death protein 1 (PD-1) signaling that causes T cell suppression. Instead, we found that LPS stimulation of monocytes led to the accumulation of extracellular ATP that impaired mitochondrial function, cell migration, IL-2 production, and T cell proliferation. Mechanistically, LPS-induced ATP accumulation exerted these suppressive effects on T cells by activating the purinergic receptor P2Y11 on the cell surface of T cells. T cell functions could be partially restored by enzymatic removal of extracellular ATP or pharmacological blocking of P2Y11 receptors. Plasma samples obtained from sepsis patients had similar suppressive effects on T cells from healthy subjects. Our findings suggest that LPS and ATP accumulation in the circulation of sepsis patients suppresses T cells by promoting inappropriate P2Y11 receptor stimulation that impairs T cell metabolism and functions. We conclude that inhibition of LPS-induced ATP release, removal of excessive extracellular ATP, or P2Y11 receptor antagonists may be potential therapeutic strategies to prevent T cell suppression and restore host immune function in sepsis.
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Affiliation(s)
| | | | | | | | - Nathan I Shapiro
- Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215 and
| | - Wolfgang G Junger
- From the Departments of Surgery and .,the Ludwig Boltzmann Institute for Traumatology, Vienna A-1200, Austria
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19
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Desperate Times Call for Desperate Measures: Self-Cannibalism Is Protective During Sepsis. Crit Care Med 2019; 45:145-147. [PMID: 27984288 DOI: 10.1097/ccm.0000000000002106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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20
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Imakita N, Kitabatake M, Ouji-Sageshima N, Hara A, Morita-Takemura S, Kasahara K, Matsukawa A, Wanaka A, Mikasa K, Ito T. Abrogated Caveolin-1 expression via histone modification enzyme Setdb2 regulates brain edema in a mouse model of influenza-associated encephalopathy. Sci Rep 2019; 9:284. [PMID: 30670717 PMCID: PMC6342998 DOI: 10.1038/s41598-018-36489-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 11/19/2018] [Indexed: 12/13/2022] Open
Abstract
Influenza-associated encephalopathy (IAE) is a serious complication that can follow influenza virus infection. Once a cytokine storm is induced during influenza virus infection, tight junction protein disruption occurs, which consequently leads to blood-brain barrier (BBB) breakdown. However, the details of IAE pathogenesis are not well understood. Here, we established a murine IAE model by administration of lipopolysaccharide following influenza virus infection. Brains from IAE model mice had significantly higher expression of type I interferons and inflammatory cytokines. In addition, the expression of Caveolin-1, one of the key proteins that correlate with protection of the BBB, was significantly lower in brains from the IAE group compared with the control group. We also found that, among 84 different histone modification enzymes, only SET domain bifurcated 2 (Setdb2), one of the histone methyltransferases that methylates the lysine 9 of histone H3, showed significantly higher expression in the IAE group compared with the control group. Furthermore, chromatin immunoprecipitation revealed that methylation of histone H3 lysine 9 was correlated with repression of the Caveolin-1 promoter region. These studies identify Caveolin-1 as a key regulator of BBB permeability in IAE and reveal that it acts through histone modification induced by Setdb2.
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Affiliation(s)
- Natsuko Imakita
- Department of Immunology, Nara Medical University, Kashihara, Nara, Japan.,Center for Infectious Diseases, Nara Medical University, Kashihara, Nara, Japan
| | | | | | - Atsushi Hara
- Department of Immunology, Nara Medical University, Kashihara, Nara, Japan
| | - Shoko Morita-Takemura
- Department of Anatomy & Neuroscience, Nara Medical University, Kashihara, Nara, Japan
| | - Kei Kasahara
- Center for Infectious Diseases, Nara Medical University, Kashihara, Nara, Japan
| | - Akihiro Matsukawa
- Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Akio Wanaka
- Department of Anatomy & Neuroscience, Nara Medical University, Kashihara, Nara, Japan
| | - Keiichi Mikasa
- Center for Infectious Diseases, Nara Medical University, Kashihara, Nara, Japan
| | - Toshihiro Ito
- Department of Immunology, Nara Medical University, Kashihara, Nara, Japan.
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21
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The protective role of human ghrelin in sepsis: Restoration of CD4 T cell proliferation. PLoS One 2018; 13:e0201139. [PMID: 30052667 PMCID: PMC6063405 DOI: 10.1371/journal.pone.0201139] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 06/12/2018] [Indexed: 02/07/2023] Open
Abstract
Decrease of CD4 T cell numbers causes immunosuppression in sepsis. We previously showed the beneficial role of ghrelin in sepsis. We hypothesize that the protective outcome of ghrelin in sepsis is mediated partially through the restoration of CD4 T cells’ proliferation. Sepsis was induced in mice by cecal ligation and puncture (CLP). The percentage of CD4 T cells in spleen was assessed by flow cytometry and their proliferation was determined by carboxyfluorescein succinimidyl ester (CSFE). Compared to sham mice, the percentages of splenic CD4 T cells were reduced by 20%, 21%, and 29% at day 1, 2 and 3 after CLP, respectively. Human ghrelin was given to 3 day septic mice by s.c. injection at 5 and 24 h after CLP. Treatment with ghrelin restored the loss of CD4 T cells by increasing their proliferation in septic mice. The expression of cyclin D1 and B1 was significantly increased, while the expression of p57 was decreased in ghrelin-treated mice compared to vehicle-treated mice in sepsis. Treatment with human ghrelin significantly increased the p-AKT levels in the spleen compared to vehicle-treated septic mice. Human ghrelin plays an important role in reestablishing the proliferation of CD4 T cells and serves as a promising therapeutic agent in sepsis.
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22
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Kumar V. T cells and their immunometabolism: A novel way to understanding sepsis immunopathogenesis and future therapeutics. Eur J Cell Biol 2018; 97:379-392. [PMID: 29773345 DOI: 10.1016/j.ejcb.2018.05.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/03/2018] [Accepted: 05/03/2018] [Indexed: 02/08/2023] Open
Abstract
Sepsis has always been considered as a big challenge for pharmaceutical companies in terms of discovering and designing new therapeutics. The pathogenesis of sepsis involves aberrant activation of innate immune cells (i.e. macrophages, neutrophils etc.) at early stages. However, a stage of immunosuppression is also observed during sepsis even in the patients who have recovered from it. This stage of immunosuppression is observed due to the loss of conventional (i.e. CD4+, CD8+) T cells, Th17 cells and an upregulation of regulatory T cells (Tregs). This process also impacts metabolic processes controlling immune cell metabolism called immunometabolism. The present review is focused on the T cell-mediated immune response, their immunometabolism and targeting T cell immunometabolism during sepsis as future therapeutic approach. The first part of the manuscripts describes an impact of sepsis on conventional T cells, Th17 cells and Tregs along with their impact on sepsis. The subsequent section further describes the immunometabolism of these cells (CD4+, CD8+, Th17, and Tregs) under normal conditions and during sepsis-induced immunosuppression. The article ends with the therapeutic targeting of T cell immunometabolism (both conventional T cells and Tregs) during sepsis as a future immunomodulatory approach for its management.
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Affiliation(s)
- V Kumar
- Children's Health Queensland Clinical Unit, School of Clinical Medicine, Mater Research, Faculty of Medicine, University of Queensland, St. Lucia, Brisbane, Queensland 4078, Australia; School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, Brisbane, Queensland 4078, Australia.
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23
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Venet F, Monneret G. Advances in the understanding and treatment of sepsis-induced immunosuppression. Nat Rev Nephrol 2017; 14:121-137. [PMID: 29225343 DOI: 10.1038/nrneph.2017.165] [Citation(s) in RCA: 464] [Impact Index Per Article: 66.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Sepsis is defined as a life-threatening organ dysfunction that is caused by a dysregulated host response to infection. Sepsis can induce acute kidney injury and multiple organ failures and represents the most common cause of death in the intensive care unit. Sepsis initiates a complex immune response that varies over time, with the concomitant occurrence of both pro-inflammatory and anti-inflammatory mechanisms. As a result, most patients with sepsis rapidly display signs of profound immunosuppression, which is associated with deleterious consequences. Scientific advances have highlighted the role of metabolic failure, epigenetic reprogramming, myeloid-derived suppressor cells, immature suppressive neutrophils and immune alterations in primary lymphoid organs (the thymus and bone marrow) in sepsis. An improved understanding of the mechanisms underlying this immunosuppression as well as of the similarities between sepsis-induced immunosuppression and immune defects in cancer or immunosenescence has led to novel therapeutic strategies aimed at stimulating immune function in patients with sepsis. Trials assessing the therapeutic benefit of IL-7, granulocyte-macrophage colony-stimulating factor (GM-CSF) and antibodies against programmed cell death protein 1 (PD1) and programmed cell death 1 ligand 1 (PDL1) for the treatment of sepsis are in progress. The reappraisal of sepsis pathophysiology has also resulted in a novel approach to the design of clinical trials evaluating sepsis treatments, based on an evaluation of the immune status and biomarker-based stratification of patients.
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Affiliation(s)
- Fabienne Venet
- Hospices Civils de Lyon, Hôpital Edouard Herriot, Immunology Department, Flow Division, 69003 Lyon, France.,Equipe d'Accueil 7426, Pathophysiology of Injury-Induced Immunosuppression, Université Claude Bernard Lyon 1, Hospices Civils de Lyon - bioMérieux, Hôpital Edouard Herriot, 69003 Lyon, France
| | - Guillaume Monneret
- Hospices Civils de Lyon, Hôpital Edouard Herriot, Immunology Department, Flow Division, 69003 Lyon, France.,Equipe d'Accueil 7426, Pathophysiology of Injury-Induced Immunosuppression, Université Claude Bernard Lyon 1, Hospices Civils de Lyon - bioMérieux, Hôpital Edouard Herriot, 69003 Lyon, France
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24
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Danahy DB, Strother RK, Badovinac VP, Griffith TS. Clinical and Experimental Sepsis Impairs CD8 T-Cell-Mediated Immunity. Crit Rev Immunol 2017; 36:57-74. [PMID: 27480902 DOI: 10.1615/critrevimmunol.2016017098] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Septic patients experience chronic immunosuppression resulting in enhanced susceptibility to infections normally controlled by T cells. Clinical research on septic patients has shown increased apoptosis and reduced total numbers of CD4 and CD8 T cells, suggesting contributing mechanism driving immunosuppression. Experimental models of sepsis, including cecal ligation and puncture, reverse translated this clinical observation to facilitate hypothesis-driven research and allow the use of an array of experimental tools to probe the impact of sepsis on T-cell immunity. In addition to numerical loss, sepsis functionally impairs the antigen-driven proliferative capacity and effector functions of CD4 and CD8 T cells. Sepsis-induced impairments in both the quantity and quality of T cells results in reduced protective capacity and increased susceptibility of mice to new or previously encountered infections. Therefore, the combined efforts of clinical and experimental sepsis research have begun to elucidate the impact of sepsis on T-cell-mediated immunity and potential T-cell-intrinsic and -extrinsic mechanisms driving chronic immunosuppression. Future work will explore the impact of sepsis on the recently appreciated tissue-resident memory (TRM) T cells, which provide robust protection against localized infections, and dendritic cells, which are needed to activate T cells and promote effective T-cell responses.
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Affiliation(s)
- Derek B Danahy
- Department of Pathology, University of Iowa, Iowa City, IA; Interdisciplinary Program in Immunology, University of Iowa, Iowa City, IA
| | | | - Vladimir P Badovinac
- Department of Pathology, Interdisciplinary Program in Immunology, University of Iowa, Iowa City, Iowa
| | - Thomas S Griffith
- Department of Urology, University of Minnesota, Minneapolis, MN; Microbiology, Immunology and Cancer Biology Graduate Program, University of Minnesota, Minneapolis, MN; Center for Immunology, University of Minnesota, Minneapolis, MN; Minneapolis VA Health Care System, Minneapolis, Minnesota
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25
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Carson WF, Kunkel SL. Regulation of Cellular Immune Responses in Sepsis by Histone Modifications. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2016; 106:191-225. [PMID: 28057212 DOI: 10.1016/bs.apcsb.2016.08.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Severe sepsis, septic shock, and related inflammatory syndromes are driven by the aberrant expression of proinflammatory mediators by immune cells. During the acute phase of sepsis, overexpression of chemokines and cytokines drives physiological stress leading to organ failure and mortality. Following recovery from sepsis, the immune system exhibits profound immunosuppression, evidenced by an inability to produce the same proinflammatory mediators that are required for normal responses to infectious microorganisms. Gene expression in inflammatory responses is influenced by the transcriptional accessibility of the chromatin, with histone posttranslational modifications determining whether inflammatory gene loci are set to transcriptionally active, repressed, or poised states. Experimental evidence indicates that histone modifications play a central role in governing the cytokine storm of severe sepsis, and that aberrant chromatin modifications induced during the acute phase of sepsis may mediate chronic immunosuppression in sepsis survivors. This review will focus on the role of histone modifications in governing immune responses in severe sepsis, with an emphasis on specific leukocyte subsets and the histone modifications observed in these cells during chronic stages of sepsis. Additionally, the expression and function of chromatin-modifying enzymes (CMEs) will be discussed in the context of severe sepsis, as potential mediators of epigenetic regulation of gene expression in sepsis responses. In summary, this review will argue for the use of chromatin modifications and CME expression in leukocytes as potential biomarkers of immunosuppression in patients with severe sepsis.
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Affiliation(s)
- W F Carson
- University of Michigan Medical School, Ann Arbor, MI, United States.
| | - S L Kunkel
- University of Michigan Medical School, Ann Arbor, MI, United States
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26
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Morandini AC, Santos CF, Yilmaz Ö. Role of epigenetics in modulation of immune response at the junction of host-pathogen interaction and danger molecule signaling. Pathog Dis 2016; 74:ftw082. [PMID: 27542389 DOI: 10.1093/femspd/ftw082] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2016] [Indexed: 12/17/2022] Open
Abstract
Epigenetic mechanisms have rapidly and controversially emerged as silent modulators of host defenses that can lead to a more prominent immune response and shape the course of inflammation in the host. Thus, the epigenetics can both drive the production of specific inflammatory mediators and control the magnitude of the host response. The epigenetic actions that are predominantly shown to modulate the host defense against microbial pathogens are DNA methylation, histone modification and the activity of non-coding RNAs. There is also growing evidence that opportunistic chronic pathogens, such as Porphyromonas gingivalis, as a microbial host subversion strategy, can epigenetically interfere with the host DNA machinery for successful colonization. Similarly, the novel involvement of small molecule 'danger signals', which are released by stressed or infected cells, at the center of host-pathogen interplay and epigenetics is developing. In this review, we systematically examine the latest knowledge within the field of epigenetics in the context of host-derived danger molecule and purinergic signaling, with a particular focus on host microbial defenses and infection-driven chronic inflammation.
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Affiliation(s)
- Ana Carolina Morandini
- Department of Biological Sciences, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil Department of Biomedical Sciences, University of the Pacific, Arthur Dugoni School of Dentistry, San Francisco, CA 94103, USA Department of Oral Health Sciences, College of Dental Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Carlos F Santos
- Department of Biological Sciences, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil
| | - Özlem Yilmaz
- Department of Oral Health Sciences, College of Dental Medicine, Medical University of South Carolina, Charleston, SC 29425, USA Department of Microbiology and Immunology, College of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
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Role of cellular events in the pathophysiology of sepsis. Inflamm Res 2016; 65:853-868. [PMID: 27392441 DOI: 10.1007/s00011-016-0970-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 05/11/2016] [Accepted: 06/25/2016] [Indexed: 12/20/2022] Open
Abstract
INTRODUCTION Sepsis is a dysregulated host immune response due to an uncontrolled infection. It is a leading cause of mortality in adult intensive care units globally. When the host immune response induced against a local infection fails to contain it locally, it progresses to sepsis, severe sepsis, septic shock and death. METHOD Literature survey was performed on the roles of different innate and adaptive immune cells in the development and progression of sepsis. Additionally, the effects of septic changes on reprogramming of different immune cells were also summarized to prepare the manuscript. FINDINGS Scientific evidences to date suggest that the loss of balance between inflammatory and anti-inflammatory responses results in reprogramming of immune cell activities that lead to irreversible tissue damaging events and multi-organ failure during sepsis. Many surface receptors expressed on immune cells at various stages of sepsis have been suggested as biomarkers for sepsis diagnosis. Various immunomodulatory therapeutics, which could improve the functions of immune cells during sepsis, were shown to restore immunological homeostasis and improve survival in animal models of sepsis. CONCLUSION In-depth and comprehensive knowledge on the immune cell activities and their correlation with severity of sepsis will help clinicians and scientists to design effective immunomodulatory therapeutics for treating sepsis.
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Rowe RK, Ellis GI, Harrison JL, Bachstetter AD, Corder GF, Van Eldik LJ, Taylor BK, Marti F, Lifshitz J. Diffuse traumatic brain injury induces prolonged immune dysregulation and potentiates hyperalgesia following a peripheral immune challenge. Mol Pain 2016; 12:12/0/1744806916647055. [PMID: 27178244 PMCID: PMC4955995 DOI: 10.1177/1744806916647055] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/30/2016] [Indexed: 01/09/2023] Open
Abstract
Background Nociceptive and neuropathic pain occurs as part of the disease process after traumatic brain injury (TBI) in humans. Central and peripheral inflammation, a major secondary injury process initiated by the traumatic brain injury event, has been implicated in the potentiation of peripheral nociceptive pain. We hypothesized that the inflammatory response to diffuse traumatic brain injury potentiates persistent pain through prolonged immune dysregulation. Results To test this, adult, male C57BL/6 mice were subjected to midline fluid percussion brain injury or to sham procedure. One cohort of mice was analyzed for inflammation-related cytokine levels in cortical biopsies and serum along an acute time course. In a second cohort, peripheral inflammation was induced seven days after surgery/injury with an intraplantar injection of carrageenan. This was followed by measurement of mechanical hyperalgesia, glial fibrillary acidic protein and Iba1 immunohistochemical analysis of neuroinflammation in the brain, and flow cytometric analysis of T-cell differentiation in mucosal lymph. Traumatic brain injury increased interleukin-6 and chemokine ligand 1 levels in the cortex and serum that peaked within 1–9 h and then resolved. Intraplantar carrageenan produced mechanical hyperalgesia that was potentiated by traumatic brain injury. Further, mucosal T cells from brain-injured mice showed a distinct deficiency in the ability to differentiate into inflammation-suppressing regulatory T cells (Tregs). Conclusions We conclude that traumatic brain injury increased the inflammatory pain associated with cutaneous inflammation by contributing to systemic immune dysregulation. Regulatory T cells are immune suppressors and failure of T cells to differentiate into regulatory T cells leads to unregulated cytokine production which may contribute to the potentiation of peripheral pain through the excitation of peripheral sensory neurons. In addition, regulatory T cells are identified as a potential target for therapeutic rebalancing of peripheral immune homeostasis to improve functional outcome and decrease the incidence of peripheral inflammatory pain following traumatic brain injury.
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Affiliation(s)
- Rachel K Rowe
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, USA Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA Phoenix Veteran Affairs Healthcare System, Phoenix, AZ, USA
| | - Gavin I Ellis
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Jordan L Harrison
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, USA Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA Arizona State University, Tempe, AZ, USA
| | - Adam D Bachstetter
- Department of Anatomy & Neurobiology, University of Kentucky College of Medicine, Lexington, KY, USA Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Gregory F Corder
- Department of Physiology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Linda J Van Eldik
- Department of Anatomy & Neurobiology, University of Kentucky College of Medicine, Lexington, KY, USA Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Bradley K Taylor
- Department of Physiology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Francesc Marti
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Jonathan Lifshitz
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, USA Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA Phoenix Veteran Affairs Healthcare System, Phoenix, AZ, USA Arizona State University, Tempe, AZ, USA
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Abstract
Supplemental digital content is available in the text. During sepsis, CD4+ T cells express activation markers within the first 24 h. In the present study, the mechanisms of T-cell activation and its consequences were addressed in an acute peritonitis model in mice. The response of CD4+ T cells to sepsis induction was compared between OTII mice, characterized by ovalbumin-specific T-cell receptor–transgenic T cells, and C57BL/6 controls (wild type [WT] mice). Because ovalbumin was absent during peritonitis, the OTII CD4+ T cells could not be activated by canonical antigen recognition. In both OTII and WT control mice, CD4+ T effector cells and CD4+ Foxp3+ regulatory T cells (Tregs) expressed the activation marker CD69 early after sepsis onset. However, full activation with upregulation of CD25 and proliferation took place only in the presence of the antigen. Besides this, the fraction of Tregs was lower in OTII than that in WT mice. Sepsis mortality was increased in OTII mice. Our data show that, in sepsis, partial activation of CD4+ T cells is induced by a T-cell receptor–independent pathway, whereas full stimulation and proliferation require a specific antigen. Antigen-dependent T-cell effector functions as well as Treg activity may contribute to sepsis survival.
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Sharma A, Yang WL, Matsuo S, Wang P. Differential alterations of tissue T-cell subsets after sepsis. Immunol Lett 2015; 168:41-50. [PMID: 26362089 DOI: 10.1016/j.imlet.2015.09.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 08/31/2015] [Accepted: 09/03/2015] [Indexed: 12/13/2022]
Abstract
Among immune cells in responding to sepsis, macrophages and neutrophils have been extensively studied, while the contribution of T lymphocytes and natural killer T (NKT) cells is less well characterized. Here we monitored tissue specific changes of T cell subsets in male C57BL/6 mice subjected to sham operation or cecal ligation and puncture (CLP) to induce polymicrobial sepsis. Thymus, spleen, liver, lungs and blood were processed and analyzed 20h later. Total lymphocyte count showed a significant reduction in septic thymus, spleen and blood but not in lungs and liver. The septic thymi were hypocellular with severe reduction in cell numbers of immature CD4(+)CD8(+) subset. CD4(+) T and CD8(+) T lymphocyte numbers in septic spleens were also significantly reduced, but the frequency of CD4(+)CD25(+) Tregs was significantly increased. In addition, naïve and Tcm CD4(+) T cell numbers were significantly reduced in the septic spleens. By contrast, in septic liver the CD8(+) T cell numbers were significantly increased, whereas NKT cell numbers were reduced, but more activated with increased CD69 and CD25 expression. In the septic lungs, the CD4(+) T and CD8(+) T cell numbers showed no significant change, whereas they were severely reduced in the septic blood. Overall, this study provides important information on the alterations of different T-cell subsets in various tissues after sepsis.
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Affiliation(s)
- Archna Sharma
- Center for Translational Research, The Feinstein Institute for Medical Research, Manhasset, NY 11030, USA.
| | - Weng-Lang Yang
- Center for Translational Research, The Feinstein Institute for Medical Research, Manhasset, NY 11030, USA; Department of Surgery, Hofstra North Shore-LIJ School of Medicine, Manhasset, NY 11030, USA.
| | - Shingo Matsuo
- Department of Surgery, Hofstra North Shore-LIJ School of Medicine, Manhasset, NY 11030, USA.
| | - Ping Wang
- Center for Translational Research, The Feinstein Institute for Medical Research, Manhasset, NY 11030, USA; Department of Surgery, Hofstra North Shore-LIJ School of Medicine, Manhasset, NY 11030, USA.
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31
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Ledderose C, Bao Y, Ledderose S, Woehrle T, Heinisch M, Yip L, Zhang J, Robson SC, Shapiro NI, Junger WG. Mitochondrial Dysfunction, Depleted Purinergic Signaling, and Defective T Cell Vigilance and Immune Defense. J Infect Dis 2015; 213:456-64. [PMID: 26150546 DOI: 10.1093/infdis/jiv373] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 06/26/2015] [Indexed: 01/08/2023] Open
Abstract
T cell suppression in sepsis is a well-known phenomenon; however, the underlying mechanisms are not fully understood. Previous studies have shown that T cell stimulation up-regulates mitochondrial adenosine triphosphate (ATP) production to fuel purinergic signaling mechanisms necessary for adequate T cell responses. Here we show that basal mitochondrial ATP production, ATP release, and stimulation of P2X1 receptors represent a standby purinergic signaling mechanism that is necessary for antigen recognition. Inhibition of this process impairs T cell vigilance and the ability of T cells to trigger T cell activation, up-regulate mitochondrial ATP production, and stimulate P2X4 and P2X7 receptors that elicit interleukin 2 production and T cell proliferation. T cells of patients with sepsis lack this standby purinergic signaling system owing to defects in mitochondrial function, ATP release, and calcium signaling. These defects impair antigen recognition and T cell function and are correlated with sepsis severity. Pharmacological targeting of these defects may improve T cell function and reduce the risk of sepsis.
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Affiliation(s)
| | | | | | - Tobias Woehrle
- Departments of Surgery Department of Anesthesiology, Ludwig-Maximilian University of Munich, Germany
| | | | - Linda Yip
- Department of Surgery, University of California, San Diego Department of Medicine, Division of Immunology and Rheumatology, Stanford University, California
| | | | | | - Nathan I Shapiro
- Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Wolfgang G Junger
- Departments of Surgery Department of Surgery, University of California, San Diego Ludwig Boltzmann Institute for Traumatology, Vienna, Austria
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Markwart R, Condotta SA, Requardt RP, Borken F, Schubert K, Weigel C, Bauer M, Griffith TS, Förster M, Brunkhorst FM, Badovinac VP, Rubio I. Immunosuppression after sepsis: systemic inflammation and sepsis induce a loss of naïve T-cells but no enduring cell-autonomous defects in T-cell function. PLoS One 2014; 9:e115094. [PMID: 25541945 PMCID: PMC4277344 DOI: 10.1371/journal.pone.0115094] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 11/18/2014] [Indexed: 11/25/2022] Open
Abstract
Sepsis describes the life-threatening systemic inflammatory response (SIRS) of an organism to an infection and is the leading cause of mortality on intensive care units (ICU) worldwide. An acute episode of sepsis is characterized by the extensive release of cytokines and other mediators resulting in a dysregulated immune response leading to organ damage and/or death. This initial pro-inflammatory burst often transits into a state of immune suppression characterised by loss of immune cells and T-cell dysfunction at later disease stages in sepsis survivors. However, despite these appreciations, the precise nature of the evoked defect in T-cell immunity in post-acute phases of SIRS remains unknown. Here we present an in-depth functional analysis of T-cell function in post-acute SIRS/sepsis. We document that T-cell function is not compromised on a per cell basis in experimental rodent models of infection-free SIRS (LPS or CpG) or septic peritonitis. Transgenic antigen-specific T-cells feature an unaltered cytokine response if challenged in vivo and ex vivo with cognate antigens. Isolated CD4(+)/CD8(+) T-cells from post-acute septic animals do not exhibit defects in T-cell receptor-mediated activation at the the level of receptor-proximal signalling, activation marker upregulation or expansion. However, SIRS/sepsis induced transient lymphopenia and gave rise to an environment of immune attenuation at post acute disease stages. Thus, systemic inflammation has an acute impact on T-cell numbers and adaptive immunity, but does not cause major cell-autonomous enduring functional defects in T-cells.
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Affiliation(s)
- Robby Markwart
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | | | - Robert P. Requardt
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - Farina Borken
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - Katja Schubert
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - Cynthia Weigel
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - Michael Bauer
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
- Dept. for Anaesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany
| | - Thomas S. Griffith
- Minneapolis Veterans Affairs Health Care System, Minneapolis, Minnesota, United States of America
- Center for Immunology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Martin Förster
- Clinic of Internal Medicine I, Jena University Hospital, Jena, Germany
| | - Frank M. Brunkhorst
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
- Center for Clinical Studies, Jena University Hospital, Jena, Germany
| | | | - Ignacio Rubio
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, Jena University Hospital, Jena, Germany
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Weiterer S, Uhle F, Siegler BH, Lichtenstern C, Bartkuhn M, Weigand MA. [Epigenetic regulation in sepsis : current state of knowledge]. Anaesthesist 2014; 64:42-55. [PMID: 25471356 DOI: 10.1007/s00101-014-2402-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sepsis is known to be a severe systemic immune reaction based on an infection of various origins. The initial immune response is accompanied by excess activation of immune cells and release of proinflammatory cytokines. Simultaneously initiated compensatory mechanisms lead to high levels of anti-inflammatory mediators to counterbalance the generalized inflammatory reaction; however, the compensatory immunoreaction itself equally overreacts and results in a prolonged sepsis-induced immunosuppression. The underlying mechanisms for these exaggerated immune responses and the resulting global immunosuppression that increase the risk for secondary infection are still unknown. Recent findings indicate that epigenetic mechanisms change basic properties of important immune cells by mechanisms leading to changes in gene expression. Dynamic exchanges of histone modifications result in a variation of transcription and seem to play a key role in cell function of macrophages and other immune cells. This article provides a current overview of epigenetic sepsis research and the sepsis-induced effects on the immune system.
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Affiliation(s)
- S Weiterer
- Klinik für Anästhesiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Deutschland,
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Cabrera-Perez J, Condotta SA, Badovinac VP, Griffith TS. Impact of sepsis on CD4 T cell immunity. J Leukoc Biol 2014; 96:767-77. [PMID: 24791959 PMCID: PMC4197564 DOI: 10.1189/jlb.5mr0114-067r] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/08/2014] [Accepted: 03/19/2014] [Indexed: 12/13/2022] Open
Abstract
Sepsis remains the primary cause of death from infection in hospital patients, despite improvements in antibiotics and intensive-care practices. Patients who survive severe sepsis can display suppressed immune function, often manifested as an increased susceptibility to (and mortality from) nosocomial infections. Not only is there a significant reduction in the number of various immune cell populations during sepsis, but there is also decreased function in the remaining lymphocytes. Within the immune system, CD4 T cells are important players in the proper development of numerous cellular and humoral immune responses. Despite sufficient clinical evidence of CD4 T cell loss in septic patients of all ages, the impact of sepsis on CD4 T cell responses is not well understood. Recent findings suggest that CD4 T cell impairment is a multipronged problem that results from initial sepsis-induced cell loss. However, the subsequent lymphopenia-induced numerical recovery of the CD4 T cell compartment leads to intrinsic alterations in phenotype and effector function, reduced repertoire diversity, changes in the composition of naive antigen-specific CD4 T cell pools, and changes in the representation of different CD4 T cell subpopulations (e.g., increases in Treg frequency). This review focuses on sepsis-induced alterations within the CD4 T cell compartment that influence the ability of the immune system to control secondary heterologous infections. The understanding of how sepsis affects CD4 T cells through their numerical loss and recovery, as well as function, is important in the development of future treatments designed to restore CD4 T cells to their presepsis state.
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Affiliation(s)
- Javier Cabrera-Perez
- Microbiology, Immunology, and Cancer Biology Graduate Program Medical Scientist Training Program
| | | | - Vladimir P Badovinac
- Department of Pathology and Interdisciplinary Program in Immunology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Thomas S Griffith
- Microbiology, Immunology, and Cancer Biology Graduate Program Center for Immunology, and Department of Urology, University of Minnesota Medical School, Minneapolis, Minnesota, USA; Minneapolis Veterans Administration Health Care System, Minneapolis, Minnesota, USA; and
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Boule LA, Winans B, Lawrence BP. Effects of developmental activation of the AhR on CD4+ T-cell responses to influenza virus infection in adult mice. ENVIRONMENTAL HEALTH PERSPECTIVES 2014; 122:1201-8. [PMID: 25051576 PMCID: PMC4216167 DOI: 10.1289/ehp.1408110] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 07/21/2014] [Indexed: 05/17/2023]
Abstract
BACKGROUND Epidemiological and animal studies indicate that maternal exposure to pollutants that bind the aryl hydrocarbon receptor (AhR) correlates with poorer ability to combat respiratory infection and lower antibody levels in the offspring. These observations point to an impact on CD4+ T cells. Yet, the consequence of developmental exposure to AhR ligands on the activation and differentiation of CD4+ T cells has not been directly examined. OBJECTIVES Our goal was to determine whether maternal exposure to an AhR ligand directly alters CD4+ T cell differentiation and function later in life. METHODS C57BL/6 mice were exposed to a prototypical AhR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in utero and via suckling. We then measured CD4+ T-cell activation and differentiation into distinct effector populations in adult offspring that were infected with influenza A virus (IAV). Reciprocal adoptive transfers were used to define whether modifications in CD4+ T-cell responses resulted from direct effects of developmental TCDD exposure on CD4+ T cells. RESULTS Developmental exposure skewed CD4+ T-cell responses to IAV infection. We observed fewer virus-specific, activated CD4+ T cells and a reduced frequency of conventional CD4+ effector-cell subsets. However, there was an increase in regulatory CD4+ T cells. Direct effects of AhR activation on CD4+ T cells resulted in impaired differentiation into conventional effector subsets; this defect was transferred to mice that had not been developmentally exposed to TCDD. CONCLUSIONS Maternal exposure to TCDD resulted in durable changes in the responsive capacity and differentiation of CD4+ T cells in adult C57BL/6 mice.
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Affiliation(s)
- Lisbeth A Boule
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
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36
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Aziz M, Yang WL, Matsuo S, Sharma A, Zhou M, Wang P. Upregulation of GRAIL is associated with impaired CD4 T cell proliferation in sepsis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2014; 192:2305-14. [PMID: 24477910 PMCID: PMC3943916 DOI: 10.4049/jimmunol.1302160] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The loss of numbers and functionality of CD4 T cells is observed in sepsis; however, the mechanism remains elusive. Gene related to anergy in lymphocytes (GRAIL) is critical for the impairment of CD4 T cell proliferation. We therefore sought to examine the role of GRAIL in CD4 T cell proliferation during sepsis. Sepsis was induced in 10-wk-old male C57BL/6 mice by cecal ligation and puncture. Splenocytes were isolated and subjected to flow cytometry to determine CD4 T cell contents. CD4 T cell proliferation was assessed by CFSE staining, and the expression of GRAIL in splenocytes was measured by immunohistochemistry, real-time PCR, and flow cytometry. The expressions of IL-2 and early growth response-2 were determined by real-time PCR. As compared with shams, the numbers of CD4 T cells were significantly reduced in spleens. Septic CD4 T cells were less efficient in proliferation than shams. The IL-2 expression was significantly reduced, whereas the GRAIL expression was significantly increased in septic mice splenocytes as compared with shams. The small interfering RNA-mediated knockdown of GRAIL expression re-established the CD4 T cell proliferation ability ex vivo. Similarly, the treatment with recombinant murine IL-2 to the septic CD4 T cells restored their proliferation ability by downregulating GRAIL expression. Our findings reveal a novel association of the increased GRAIL expression with impaired CD4 T cell proliferation, implicating an emerging therapeutic tool in sepsis.
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Affiliation(s)
- Monowar Aziz
- Center for Translational Research, Feinstein Institute for Medical Research, Manhasset, NY 11030
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Hotchkiss RS, Monneret G, Payen D. Sepsis-induced immunosuppression: from cellular dysfunctions to immunotherapy. Nat Rev Immunol 2013; 13:862-74. [PMID: 24232462 PMCID: PMC4077177 DOI: 10.1038/nri3552] [Citation(s) in RCA: 1624] [Impact Index Per Article: 147.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Sepsis - which is a severe life-threatening infection with organ dysfunction - initiates a complex interplay of host pro-inflammatory and anti-inflammatory processes. Sepsis can be considered a race to the death between the pathogens and the host immune system, and it is the proper balance between the often competing pro- and anti-inflammatory pathways that determines the fate of the individual. Although the field of sepsis research has witnessed the failure of many highly touted clinical trials, a better understanding of the pathophysiological basis of the disorder and the mechanisms responsible for the associated pro- and anti-inflammatory responses provides a novel approach for treating this highly lethal condition. Biomarker-guided immunotherapy that is administered to patients at the proper immune phase of sepsis is potentially a major advance in the treatment of sepsis and in the field of infectious disease.
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Affiliation(s)
- Richard S Hotchkiss
- Department of Anesthesiology, Medicine, and Surgery, Washington University School of Medicine, St Louis, Missouri 63110, USA
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38
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STAT3-mediated IL-17 production by postseptic T cells exacerbates viral immunopathology of the lung. Shock 2013; 38:515-23. [PMID: 23042197 DOI: 10.1097/shk.0b013e31826f862c] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Survivors of severe sepsis exhibit increased morbidity and mortality in response to secondary infections. Although bacterial secondary infections have been widely studied, there remains a paucity of data concerning viral infections after sepsis. In an experimental mouse model of severe sepsis (cecal ligation and puncture [CLP]) followed by respiratory syncytial virus (RSV) infection, exacerbated immunopathology was observed in the lungs of CLP mice compared with RSV-infected sham surgery mice. This virus-associated immunopathology was evidenced by increased mucus production in the lungs of RSV-infected CLP mice and correlated with increased IL-17 production in the lungs. Respiratory syncytial virus-infected CLP mice exhibited increased levels of TH2 cytokines and reduced interferon γ in the lungs and lymph nodes compared with RSV-infected sham mice. In addition, CD4 T cells from CLP mice produced increased IL-17 in vitro irrespective of the presence of exogenous cytokines or blocking antibodies. This increased IL-17 production correlated with increased STAT3 transcription factor binding to the IL-17 promoter in CD4 T cells from CLP mice. Furthermore, in vivo neutralization of IL-17 before RSV infection led to a significant reduction in virus-induced mucus production and TH2 cytokines. Taken together, these data provide evidence that postseptic CD4 T cells are primed toward IL-17 production via increased STAT3-mediated gene transcription, which may contribute to the immunopathology of a secondary viral infection.
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Mohr A, Polz J, Martin EM, Griessl S, Kammler A, Pötschke C, Lechner A, Bröker BM, Mostböck S, Männel DN. Sepsis leads to a reduced antigen-specific primary antibody response. Eur J Immunol 2011; 42:341-52. [PMID: 22105154 DOI: 10.1002/eji.201141692] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 10/17/2011] [Accepted: 11/14/2011] [Indexed: 01/13/2023]
Abstract
Immunosuppression, impaired cytokine production and high susceptibility to secondary infections are characteristic for septic patients, and for mice after induction of polymicrobial septic peritonitis by sublethal cecal ligation and puncture (CLP). Here, we demonstrate that CLP markedly altered subsequent B-cell responses. Total IgG and IgM levels, as well as the memory B-cell response, were increased in septic mice, but antigen-specific primary antibody production was strongly impaired. We found that two days after CLP, CD11b(+) splenocytes were activated as demonstrated by the increased expression of activation markers, expression of arginase and production of NO by immature myeloid cells. The in vivo clearance of a bacterial infection was not impaired. DCs demonstrated reduced IL-12 production and altered antigen presentation, resulting in decreased proliferation but enhanced IFN-γ production by CD4(+) cells. CD4(+) T cells from mice immunized on day 2 after CLP showed reduced Th1 and Th2 cytokine production. In addition, there was an increase in Treg cells. Interestingly, levels of immature B cells decreased but levels of mature B cells increased two days after CLP. However, adoptive transfer of naïve CD4(+) T cells, naïve B cells, or naïve DCs did not rescue the antigen-specific antibody response.
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Affiliation(s)
- Arno Mohr
- Institute of Immunology, University of Regensburg, Regensburg, Germany
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40
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Carson WF, Ito T, Schaller M, Cavassani KA, Chensue SW, Kunkel SL. Dysregulated cytokine expression by CD4+ T cells from post-septic mice modulates both Th1 and Th2-mediated granulomatous lung inflammation. PLoS One 2011; 6:e20385. [PMID: 21655295 PMCID: PMC3105020 DOI: 10.1371/journal.pone.0020385] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 04/22/2011] [Indexed: 11/19/2022] Open
Abstract
Previous epidemiological studies in humans and experimental studies in animals indicate that survivors of severe sepsis exhibit deficiencies in the activation and effector function of immune cells. In particular, CD4+ T lymphocytes can exhibit reduced proliferative capacity and improper cytokine responses following sepsis. To further investigate the cell-intrinsic defects of CD4+ T cells following sepsis, splenic CD4+ T cells from sham surgery and post-septic mice were transferred into lymphopenic mice. These recipient mice were then subjected to both TH1-(purified protein derivative) and TH2-(Schistosoma mansoni egg antigen) driven models of granulomatous lung inflammation. Post-septic CD4+ T cells mediated smaller TH1 and larger TH2 lung granulomas as compared to mice receiving CD4+ T cells from sham surgery donors. However, cytokine production by lymph node cells in antigen restimulation assays indicated increased pan-specific cytokine expression by post-septic CD4+ T cell recipient mice in both TH1 and TH2 granuloma models. These include increased production of TH2 cytokines in TH1 inflammation, and increased production of TH1 cytokines in TH2 inflammation. These results suggest that cell-intrinsic defects in CD4+ T cell effector function can have deleterious effects on inflammatory processes post-sepsis, due to a defect in the proper regulation of TH-specific cytokine expression.
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Affiliation(s)
- William F Carson
- Department of Pathology, University of Michigan Medical School, University of Michigan, Ann Arbor, Michigan, United States of America.
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Carson WF, Cavassani KA, Dou Y, Kunkel SL. Epigenetic regulation of immune cell functions during post-septic immunosuppression. Epigenetics 2011; 6:273-83. [PMID: 21048427 DOI: 10.4161/epi.6.3.14017] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Studies in humans and animal models indicate that profound immunosuppression is one of the chronic consequences of severe sepsis. This immune dysfunction encompasses deficiencies in activation of cells in both the myeloid and lymphoid cell lineages. As a result, survivors of severe sepsis are at risk of succumbing to infections perpetrated by opportunistic pathogens that are normally controlled by a fully functioning immune system. Recent studies have indicated that epigenetic mechanisms may be one driving force behind this immunosuppression, through suppression of proinflammatory gene production and subsequent immune cell activation, proliferation and effector function. A better understanding of epigenetics and post-septic immunosuppression can improve our diagnostic tools and may be an important potential source of novel molecular targets for new therapies. This review will discuss important pathways of immune cell activation affected by severe sepsis, and highlight pathways of epigenetic regulation that may be involved in post-septic immunosuppression.
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Affiliation(s)
- William F Carson
- Department of Pathology, University of Michigan, Ann Arbor, USA.
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Early-age-related changes in proteostasis augment immunopathogenesis of sepsis and acute lung injury. PLoS One 2010; 5:e15480. [PMID: 21085581 PMCID: PMC2981560 DOI: 10.1371/journal.pone.0015480] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2010] [Accepted: 09/23/2010] [Indexed: 12/29/2022] Open
Abstract
Background The decline of proteasomal activity is known to be associated with the age-related disorders but the early events involved in this process are not apparent. To address this, we investigated the early-age-related (pediatric vs. adult) mechanisms that augment immunopathogenesis of sepsis and acute lung injury. Methodology/Principal Findings The 3-weeks (pediatric) and 6-months (adult) old C57BL/6 mice were selected as the study groups. Mice were subjected to 1×20 cecal ligation and puncture (CLP) mediated sepsis or intratracheal Psuedomonas aeruginosa (Pa)-LPS induced acute lung injury (ALI).We observed a significant increase in basal levels of pro-inflammatory cytokine, IL-6 and neutrophil activity marker, myeloperoxidase (MPO) in the adult mice compared to the pediatric indicating the age-related constitutive increase in inflammatory response. Next, we found that age-related decrease in PSMB6 (proteasomal subunit) expression in adult mice results in accumulation of ubiquitinated proteins that triggers the unfolded protein response (UPR). We identified that Pa-LPS induced activation of UPR modifier, p97/VCP (valosin-containing protein) in the adult mice lungs correlates with increase in Pa-LPS induced NFκB levels. Moreover, we observed a constitutive increase in p-eIF2α indicating a protective ER stress response to accumulation of ubiquitinated-proteins. We used MG-132 treatment of HBE cells as an in vitro model to standardize the efficacy of salubrinal (inhibitor of eIF2α de-phosphorylation) in controlling the accumulation of ubiquitinated proteins and the NFκB levels. Finally, we evaluated the therapeutic efficacy of salubrinal to correct proteostasis-imbalance in the adult mice based on its ability to control CLP induced IL-6 secretion or recruitment of pro-inflammatory cells. Conclusions/Significance Our data demonstrate the critical role of early-age-related proteostasis-imbalance as a novel mechanism that augments the NFκB mediated inflammation in sepsis and ALI. Moreover, our data suggest the therapeutic efficacy of salubrinal in restraining NFκB mediated inflammation in the adult or older subjects.
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