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Driver JP, de Carvalho Madrid DM, Gu W, Artiaga BL, Richt JA. Modulation of Immune Responses to Influenza A Virus Vaccines by Natural Killer T Cells. Front Immunol 2020; 11:2172. [PMID: 33193296 PMCID: PMC7606973 DOI: 10.3389/fimmu.2020.02172] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 08/10/2020] [Indexed: 12/20/2022] Open
Abstract
Influenza A viruses (IAVs) circulate widely among different mammalian and avian hosts and sometimes give rise to zoonotic infections. Vaccination is a mainstay of IAV prevention and control. However, the efficacy of IAV vaccines is often suboptimal because of insufficient cross-protection among different IAV genotypes and subtypes as well as the inability to keep up with the rapid molecular evolution of IAV strains. Much attention is focused on improving IAV vaccine efficiency using adjuvants, which are substances that can modulate and enhance immune responses to co-administered antigens. The current review is focused on a non-traditional approach of adjuvanting IAV vaccines by therapeutically targeting the immunomodulatory functions of a rare population of innate-like T lymphocytes called invariant natural killer T (iNKT) cells. These cells bridge the innate and adaptive immune systems and are capable of stimulating a wide array of immune cells that enhance vaccine-mediated immune responses. Here we discuss the factors that influence the adjuvant effects of iNKT cells for influenza vaccines as well as the obstacles that must be overcome before this novel adjuvant approach can be considered for human or veterinary use.
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Affiliation(s)
- John P Driver
- Department of Animal Sciences, University of Florida, Gainesville, FL, United States
| | | | - Weihong Gu
- Department of Animal Sciences, University of Florida, Gainesville, FL, United States
| | - Bianca L Artiaga
- Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - Jürgen A Richt
- Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
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Patel VI, Booth JL, Dozmorov M, Brown BR, Metcalf JP. Anthrax Edema and Lethal Toxins Differentially Target Human Lung and Blood Phagocytes. Toxins (Basel) 2020; 12:toxins12070464. [PMID: 32698436 PMCID: PMC7405021 DOI: 10.3390/toxins12070464] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 12/26/2022] Open
Abstract
Bacillus anthracis, the causative agent of inhalation anthrax, is a serious concern as a bioterrorism weapon. The vegetative form produces two exotoxins: Lethal toxin (LT) and edema toxin (ET). We recently characterized and compared six human airway and alveolar-resident phagocyte (AARP) subsets at the transcriptional and functional levels. In this study, we examined the effects of LT and ET on these subsets and human leukocytes. AARPs and leukocytes do not express high levels of the toxin receptors, tumor endothelium marker-8 (TEM8) and capillary morphogenesis protein-2 (CMG2). Less than 20% expressed surface TEM8, while less than 15% expressed CMG2. All cell types bound or internalized protective antigen, the common component of the two toxins, in a dose-dependent manner. Most protective antigen was likely internalized via macropinocytosis. Cells were not sensitive to LT-induced apoptosis or necrosis at concentrations up to 1000 ng/mL. However, toxin exposure inhibited B. anthracis spore internalization. This inhibition was driven primarily by ET in AARPs and LT in leukocytes. These results support a model of inhalation anthrax in which spores germinate and produce toxins. ET inhibits pathogen phagocytosis by AARPs, allowing alveolar escape. In late-stage disease, LT inhibits phagocytosis by leukocytes, allowing bacterial replication in the bloodstream.
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Affiliation(s)
- Vineet I. Patel
- Department of Medicine, Pulmonary, Critical Care & Sleep Medicine, the University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (V.I.P.); (J.L.B.); (B.R.B.)
| | - J. Leland Booth
- Department of Medicine, Pulmonary, Critical Care & Sleep Medicine, the University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (V.I.P.); (J.L.B.); (B.R.B.)
| | - Mikhail Dozmorov
- Department of Biostatistics, Virginia Commonwealth University, Richmond, VA 23298, USA;
| | - Brent R. Brown
- Department of Medicine, Pulmonary, Critical Care & Sleep Medicine, the University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (V.I.P.); (J.L.B.); (B.R.B.)
| | - Jordan P. Metcalf
- Department of Medicine, Pulmonary, Critical Care & Sleep Medicine, the University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (V.I.P.); (J.L.B.); (B.R.B.)
- Department of Microbiology and Immunology, the University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
- Correspondence:
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Khandia R, Pattnaik B, Rajukumar K, Pateriya A, Bhatia S, Murugkar H, Prakash A, Pradhan HK, Dhama K, Munjal A, Joshi SK. Anti-proliferative role of recombinant lethal toxin of Bacillus anthracis on primary mammary ductal carcinoma cells revealing its therapeutic potential. Oncotarget 2018; 8:35835-35847. [PMID: 28415766 PMCID: PMC5482621 DOI: 10.18632/oncotarget.16214] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 03/07/2017] [Indexed: 12/11/2022] Open
Abstract
Bacillus anthracis secretes three secretary proteins; lethal factor (LF), protective antigen (PA) and edema factor (EF). The LF has ability to check proliferation of mammary tumors, chiefly depending on mitogen activated protein kinase (MAPK) signaling pathway. Evaluation of therapeutic potential of recombinant LF (rLF), recombinant PA (rPA) and lethal toxin (rLF + rPA = LeTx) on the primary mammary ductal carcinoma cells revealed significant (p < 0.01) reduction in proliferation of tumor cells with mean inhibition indices of 28.0 ± 1.37% and 19.6 ± 1.47% respectively. However, treatment with rPA alone had no significant anti-proliferative effect as evident by low mean inhibition index of 3.4 ± 3.87%. The higher inhibition index observed for rLF alone as compared to LeTx is contrary to the existing knowledge on LF, which explains the requirement of PA dependent endocytosis for its enzymatic activity. Therefore, the plausible existence of PA independent mode of action of LF including direct receptor mediated endocytosis or modulation of signal transduction cascade via unknown means is hypothesized. In silico protein docking analysis of other cellular receptors for any plausibility to play the role of receptor for LF revealed c-Met receptor showing strongest affinity for LF (H bond = 19; Free energy = −773.96), followed by nerve growth factor receptor (NGFR) and human epidermal growth factor receptor (HER)-1. The study summarizes the use of rLF or LeTx as therapeutic molecule against primary mammary ductal carcinoma cells and also the c-Met as potential alternative receptor for LF to mediate and modulate PA independent signal transduction.
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Affiliation(s)
- Rekha Khandia
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India.,Department of Biochemistry and Genetics, Barkatullah University, Bhopal, Madhya Pradesh, India
| | - Bramhadev Pattnaik
- Project Directorate on Foot and Mouth Disease, Mukteswar, Uttarakhand, India
| | | | - Atul Pateriya
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - Sandeep Bhatia
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - Harshad Murugkar
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - Anil Prakash
- Department of Microbiology, Barkatullah University, Bhopal, Madhya Pradesh, India
| | - Hare Krishna Pradhan
- Ex-Avian Influenza National Consultant, Indian Office of WHO Consultant, Bhartiya Kala Kendra, New Delhi, India
| | - Kuldeep Dhama
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly Uttar Pradesh, India
| | - Ashok Munjal
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal, Madhya Pradesh, India
| | - Sunil K Joshi
- Cellular Immunology Laboratory, Frank Reidy Research Center of Bioelectrics, College of Health Sciences, Old Dominion University Norfolk, VA USA
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Seshadri S, Allan DSJ, Carlyle JR, Zenewicz LA. Bacillus anthracis lethal toxin negatively modulates ILC3 function through perturbation of IL-23-mediated MAPK signaling. PLoS Pathog 2017; 13:e1006690. [PMID: 29059238 PMCID: PMC5695638 DOI: 10.1371/journal.ppat.1006690] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 11/02/2017] [Accepted: 10/10/2017] [Indexed: 12/30/2022] Open
Abstract
Bacillus anthracis, the causative agent of anthrax, secretes lethal toxin that down-regulates immune functions. Translocation of B. anthracis across mucosal epithelia is key for its dissemination and pathogenesis. Group 3 innate lymphocytes (ILC3s) are important in mucosal barrier maintenance due to their expression of the cytokine IL-22, a critical regulator of tissue responses and repair during homeostasis and inflammation. We found that B. anthracis lethal toxin perturbed ILC3 function in vitro and in vivo, revealing an unknown IL-23-mediated MAPK signaling pathway. Lethal toxin had no effects on the canonical STAT3-mediated IL-23 signaling pathway. Rather lethal toxin triggered the loss of several MAP2K kinases, which correlated with reduced activation of downstream ERK1/2 and p38, respectively. Inhibition studies showed the importance of MAPK signaling in IL-23-mediated production of IL-22. Our finding that MAPK signaling is required for optimal IL-22 production in ILC3s may lead to new approaches for targeting IL-22 biology.
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Affiliation(s)
- Sudarshan Seshadri
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - David S. J. Allan
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
- Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - James R. Carlyle
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
- Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Lauren A. Zenewicz
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
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Le Gars M, Haustant M, Klezovich-Benard M, Paget C, Trottein F, Goossens PL, Tournier JN. [iNKT cells: potential therapeutic targets to fight anthrax]. Med Sci (Paris) 2017; 33:488-490. [PMID: 28612722 DOI: 10.1051/medsci/20173305010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mathieu Le Gars
- Pathogénie des toxi-infections bactériennes, Institut Pasteur, 28, rue du Docteur Roux, 75724 Paris, France - Blish lab, department of medicine, Stanford immunology, Stanford university, Stanford, CA, États-Unis
| | - Michel Haustant
- Pathogénie des toxi-infections bactériennes, Institut Pasteur, 28, rue du Docteur Roux, 75724 Paris, France
| | - Maria Klezovich-Benard
- Pathogénie des toxi-infections bactériennes, Institut Pasteur, 28, rue du Docteur Roux, 75724 Paris, France
| | - Christophe Paget
- Centre d'infection et d'immunité de Lille, Inserm U1019, CNRS UMR 8204, université de Lille, CHU Lille et Institut Pasteur de Lille, 1, rue du professeur Calmette, 59000 Lille, France
| | - François Trottein
- Centre d'infection et d'immunité de Lille, Inserm U1019, CNRS UMR 8204, université de Lille, CHU Lille et Institut Pasteur de Lille, 1, rue du professeur Calmette, 59000 Lille, France
| | - Pierre L Goossens
- Pathogénie des toxi-infections bactériennes, Institut Pasteur, 28, rue du Docteur Roux, 75724 Paris, France
| | - Jean-Nicolas Tournier
- Pathogénie des toxi-infections bactériennes, Institut Pasteur, 28, rue du Docteur Roux, 75724 Paris, France - Unité interactions hôte-agents pathogènes, institut de recherche biomédicale des armées, BP73, 91223 Brétigny-sur-Orge, France
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Le Gars M, Haustant M, Klezovich-Bénard M, Paget C, Trottein F, Goossens PL, Tournier JN. Mechanisms of Invariant NKT Cell Activity in Restraining Bacillus anthracis Systemic Dissemination. THE JOURNAL OF IMMUNOLOGY 2016; 197:3225-3232. [PMID: 27605012 DOI: 10.4049/jimmunol.1600830] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/12/2016] [Indexed: 12/31/2022]
Abstract
Exogenous activation of invariant NKT (iNKT) cells by the superagonist α-galactosylceramide (α-GalCer) can protect against cancer, autoimmune diseases, and infections. In the current study, we investigated the effect of α-GalCer against Bacillus anthracis infection, the agent of anthrax. Using an experimental model of s.c. B. anthracis infection (an encapsulated nontoxigenic strain), we show that concomitant administration of α-GalCer delayed B. anthracis systemic dissemination and prolonged mouse survival. Depletion of subcapsular sinus CD169-positive macrophages by clodronate-containing liposome was associated with a lack of iNKT cell activation in the draining lymph nodes (dLNs) and prevented the protective effect of α-GalCer on bacterial dissemination out of the dLNs. Production of IFN-γ triggered chemokine (C-C motif) ligand 3 synthesis and recruitment of neutrophils in the dLNs, leading to the restraint of B. anthracis dissemination. Our data highlight a novel immunological pathway leading to the control of B. anthracis infection, a finding that might lead to improved therapeutics based on iNKT cells.
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Affiliation(s)
- Mathieu Le Gars
- Pathogénie des Toxi-Infections Bactériennes, Département de Microbiologie, Institut Pasteur, 75724 Paris, France;
| | - Michel Haustant
- Pathogénie des Toxi-Infections Bactériennes, Département de Microbiologie, Institut Pasteur, 75724 Paris, France
| | - Maria Klezovich-Bénard
- Pathogénie des Toxi-Infections Bactériennes, Département de Microbiologie, Institut Pasteur, 75724 Paris, France
| | - Christophe Paget
- Centre d'Infection et d'Immunité de Lille, INSERM U1019, CNRS UMR 8204, Universitaire de Lille, Centre Hospitalier Régional Universitaire de Lille-Institut Pasteur de Lille, 59000 Lille, France
| | - François Trottein
- Centre d'Infection et d'Immunité de Lille, INSERM U1019, CNRS UMR 8204, Universitaire de Lille, Centre Hospitalier Régional Universitaire de Lille-Institut Pasteur de Lille, 59000 Lille, France
| | - Pierre L Goossens
- Pathogénie des Toxi-Infections Bactériennes, Département de Microbiologie, Institut Pasteur, 75724 Paris, France
| | - Jean-Nicolas Tournier
- Pathogénie des Toxi-Infections Bactériennes, Département de Microbiologie, Institut Pasteur, 75724 Paris, France.,Unité Interactions Hôte-Agents Pathogènes, Institut de Recherche Biomédicale des Armées, 91223 Brétigny-sur-Orge, France; and.,Ecole du Val-de-Grâce, 75005 Paris, France
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7
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Invariant natural killer T cells: front line fighters in the war against pathogenic microbes. Immunogenetics 2016; 68:639-48. [PMID: 27368411 DOI: 10.1007/s00251-016-0933-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 04/21/2016] [Indexed: 12/22/2022]
Abstract
Invariant natural killer T (iNKT) cells constitute a unique subset of innate-like T cells that have been shown to have crucial roles in a variety of immune responses. iNKT cells are characterized by their expression of both NK cell markers and an invariant T cell receptor (TCR) α chain, which recognizes glycolipids presented by the MHC class I-like molecule CD1d. Despite having a limited antigen repertoire, the iNKT cell response can be very complex, and participate in both protective and harmful immune responses. The protective role of these cells against a variety of pathogens has been particularly well documented. Through the use of these pathogen models, our knowledge of the breadth of the iNKT cell response has been expanded. Specific iNKT cell antigens have been isolated from several different bacteria, from which iNKT cells are critical for protection in mouse models. These responses can be generated by direct, CD1d-mediated activation, or indirect, cytokine-mediated activation, or a combination of the two. This can lead to secretion of a variety of different Th1, Th2, or Th17 cytokines, which differentially impact the downstream immune response against these pathogens. This critical role is emphasized by the conservation of these cells between mice and humans, warranting further investigation into how iNKT cells participate in protective immune responses, with the ultimate goal of harnessing their potential for treatment.
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Devera TS, Prusator DK, Joshi SK, Ballard JD, Lang ML. Immunization of Mice with Anthrax Protective Antigen Limits Cardiotoxicity but Not Hepatotoxicity Following Lethal Toxin Challenge. Toxins (Basel) 2015; 7:2371-84. [PMID: 26120785 PMCID: PMC4516918 DOI: 10.3390/toxins7072371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 06/15/2015] [Accepted: 06/18/2015] [Indexed: 11/16/2022] Open
Abstract
Protective immunity against anthrax is inferred from measurement of vaccine antigen-specific neutralizing antibody titers in serum samples. In animal models, in vivo challenges with toxin and/or spores can also be performed. However, neither of these approaches considers toxin-induced damage to specific organ systems. It is therefore important to determine to what extent anthrax vaccines and existing or candidate adjuvants can provide organ-specific protection against intoxication. We therefore compared the ability of Alum, CpG DNA and the CD1d ligand α-galactosylceramide (αGC) to enhance protective antigen-specific antibody titers, to protect mice against challenge with lethal toxin, and to block cardiotoxicity and hepatotoxicity. By measurement of serum cardiac Troponin I (cTnI), and hepatic alanine aminotransferase (ALT), and aspartate aminotransferase (AST), it was apparent that neither vaccine modality prevented hepatic intoxication, despite high Ab titers and ultimate survival of the subject. In contrast, cardiotoxicity was greatly diminished by prior immunization. This shows that a vaccine that confers survival following toxin exposure may still have an associated morbidity. We propose that organ-specific intoxication should be monitored routinely during research into new vaccine modalities.
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Affiliation(s)
- T Scott Devera
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Dawn K Prusator
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Sunil K Joshi
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA.
| | - Jimmy D Ballard
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Mark L Lang
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
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Matangkasombut P, Chan-in W, Opasawaschai A, Pongchaikul P, Tangthawornchaikul N, Vasanawathana S, Limpitikul W, Malasit P, Duangchinda T, Screaton G, Mongkolsapaya J. Invariant NKT cell response to dengue virus infection in human. PLoS Negl Trop Dis 2014; 8:e2955. [PMID: 24945350 PMCID: PMC4063705 DOI: 10.1371/journal.pntd.0002955] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 05/07/2014] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Dengue viral infection is a global health threat without vaccine or specific treatment. The clinical outcome varies from asymptomatic, mild dengue fever (DF) to severe dengue hemorrhagic fever (DHF). While adaptive immune responses were found to be detrimental in the dengue pathogenesis, the roles of earlier innate events remain largely uninvestigated. Invariant natural killer T (iNKT) cells represent innate-like T cells that could dictate subsequent adaptive response but their role in human dengue virus infection is not known. We hypothesized that iNKT cells play a role in human dengue infection. METHODS Blood samples from a well-characterized cohort of children with DF, DHF, in comparison to non-dengue febrile illness (OFI) and healthy controls at various time points were studied. iNKT cells activation were analyzed by the expression of CD69 by flow cytometry. Their cytokine production was then analyzed after α-GalCer stimulation. Further, the CD1d expression on monocytes, and CD69 expression on conventional T cells were measured. RESULTS iNKT cells were activated during acute dengue infection. The level of iNKT cell activation associates with the disease severity. Furthermore, these iNKT cells had altered functional response to subsequent ex vivo stimulation with α-GalCer. Moreover, during acute dengue infection, monocytic CD1d expression was also upregulated and conventional T cells also became activated. CONCLUSION iNKT cells might play an early and critical role in the pathogenesis of severe dengue viral infection in human. Targeting iNKT cells and CD1d serve as a potential therapeutic strategy for severe dengue infection in the future.
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Affiliation(s)
- Ponpan Matangkasombut
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
- Systems Biology of Diseases Research Unit, Faculty of Science, Mahidol University, Bangkok, Thailand
- Center of Emerging and Neglected Infectious Diseases, Mahidol University, Bangkok, Thailand
| | - Wilawan Chan-in
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Anunya Opasawaschai
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Pisut Pongchaikul
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Nattaya Tangthawornchaikul
- Medical Biotechnology Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand
| | | | | | - Prida Malasit
- Center of Emerging and Neglected Infectious Diseases, Mahidol University, Bangkok, Thailand
- Medical Biotechnology Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand
- Dengue Hemorrhagic Fever Research Unit, Office for Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Thaneeya Duangchinda
- Center of Emerging and Neglected Infectious Diseases, Mahidol University, Bangkok, Thailand
- Medical Biotechnology Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand
| | - Gavin Screaton
- Division of Immunology and Inflammation, Department of Medicine, Hammersmith campus, Imperial College London, London, United Kingdom
| | - Juthathip Mongkolsapaya
- Center of Emerging and Neglected Infectious Diseases, Mahidol University, Bangkok, Thailand
- Dengue Hemorrhagic Fever Research Unit, Office for Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Division of Immunology and Inflammation, Department of Medicine, Hammersmith campus, Imperial College London, London, United Kingdom
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Ascough S, Ingram RJ, Chu KK, Reynolds CJ, Musson JA, Doganay M, Metan G, Ozkul Y, Baillie L, Sriskandan S, Moore SJ, Gallagher TB, Dyson H, Williamson ED, Robinson JH, Maillere B, Boyton RJ, Altmann DM. Anthrax lethal factor as an immune target in humans and transgenic mice and the impact of HLA polymorphism on CD4+ T cell immunity. PLoS Pathog 2014; 10:e1004085. [PMID: 24788397 PMCID: PMC4006929 DOI: 10.1371/journal.ppat.1004085] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 03/07/2014] [Indexed: 11/23/2022] Open
Abstract
Bacillus anthracis produces a binary toxin composed of protective antigen (PA) and one of two subunits, lethal factor (LF) or edema factor (EF). Most studies have concentrated on induction of toxin-specific antibodies as the correlate of protective immunity, in contrast to which understanding of cellular immunity to these toxins and its impact on infection is limited. We characterized CD4+ T cell immunity to LF in a panel of humanized HLA-DR and DQ transgenic mice and in naturally exposed patients. As the variation in antigen presentation governed by HLA polymorphism has a major impact on protective immunity to specific epitopes, we examined relative binding affinities of LF peptides to purified HLA class II molecules, identifying those regions likely to be of broad applicability to human immune studies through their ability to bind multiple alleles. Transgenics differing only in their expression of human HLA class II alleles showed a marked hierarchy of immunity to LF. Immunogenicity in HLA transgenics was primarily restricted to epitopes from domains II and IV of LF and promiscuous, dominant epitopes, common to all HLA types, were identified in domain II. The relevance of this model was further demonstrated by the fact that a number of the immunodominant epitopes identified in mice were recognized by T cells from humans previously infected with cutaneous anthrax and from vaccinated individuals. The ability of the identified epitopes to confer protective immunity was demonstrated by lethal anthrax challenge of HLA transgenic mice immunized with a peptide subunit vaccine comprising the immunodominant epitopes that we identified. Anthrax is of concern with respect to human exposure in endemic regions, concerns about bioterrorism and the considerable global burden of livestock infections. The immunology of this disease remains poorly understood. Vaccination has been based on B. anthracis filtrates or attenuated spore-based vaccines, with more recent trials of next-generation recombinant vaccines. Approaches generally require extensive vaccination regimens and there have been concerns about immunogenicity and adverse reactions. An ongoing need remains for rationally designed, effective and safe anthrax vaccines. The importance of T cell stimulating vaccines is inceasingly recognized. An essential step is an understanding of immunodominant epitopes and their relevance across the diverse HLA immune response genes of human populations. We characterized CD4 T cell immunity to anthrax Lethal Factor (LF), using HLA transgenic mice, as well as testing candidate peptide epitopes for binding to a wide range of HLA alleles. We identified anthrax epitopes, noteworthy in that they elicit exceptionally strong immunity with promiscuous binding across multiple HLA alleles and isotypes. T cell responses in humans exposed to LF through either natural anthrax infection or vaccination were also examined. Epitopes identified as candidates were used to protect HLA transgenic mice from anthrax challenge.
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Affiliation(s)
- Stephanie Ascough
- Department of Medicine, Imperial College London, London, United Kingdom
| | - Rebecca J. Ingram
- Centre for Infection and Immunity, Queen's University Belfast, Belfast, United Kingdom
| | - Karen K. Chu
- Department of Medicine, Imperial College London, London, United Kingdom
| | | | - Julie A. Musson
- Institute for Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Mehmet Doganay
- Department of Infectious Disease, Erciyes University Hospital, Kayseri, Turkey
| | - Gökhan Metan
- Department of Infectious Disease, Erciyes University Hospital, Kayseri, Turkey
| | - Yusuf Ozkul
- Department of Medical Genetics, Erciyes University Hospital, Kayseri, Turkey
| | - Les Baillie
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom
| | | | - Stephen J. Moore
- BIOMET, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Theresa B. Gallagher
- BIOMET, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Hugh Dyson
- Defence Science Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - E. Diane Williamson
- Defence Science Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - John H. Robinson
- Institute for Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Bernard Maillere
- CEA, iBiTecS, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), Gif Sur Yvette, France
| | | | - Daniel M. Altmann
- Department of Medicine, Imperial College London, London, United Kingdom
- * E-mail:
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Wu J, Shin J, Xie D, Wang H, Gao J, Zhong XP. Tuberous sclerosis 1 promotes invariant NKT cell anergy and inhibits invariant NKT cell-mediated antitumor immunity. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2014; 192:2643-50. [PMID: 24532578 PMCID: PMC3965184 DOI: 10.4049/jimmunol.1302076] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Development of effective immune therapies for cancer patients requires better understanding of hurdles that prevent the generation of effective antitumor immune responses. Administration of α-galactosylceramide (α-GalCer) in animals enhances antitumor immunity via activation of the invariant NKT (iNKT) cells. However, repeated injections of α-GalCer result in long-term unresponsiveness or anergy of iNKT cells, severely limiting its efficacy in tumor eradication. The mechanisms leading to iNKT cell anergy remain poorly understood. We report in this study that the tuberous sclerosis 1 (TSC1), a negative regulator of mTOR signaling, plays a crucial role in iNKT cell anergy. Deficiency of TSC1 in iNKT cells results in resistance to α-GalCer-induced anergy, manifested by increased expansion of and cytokine production by iNKT cells in response to secondary Ag stimulation. It is correlated with impaired upregulation of programmed death-1, Egr2, and Grail. Moreover, TSC1-deficient iNKT cells display enhanced antitumor immunity in a melanoma lung metastasis model. Our data suggest targeting TSC1/2 as a strategy for boosting antitumor immune therapy.
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Affiliation(s)
- Jinhong Wu
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710
- Division of Pediatric Pulmonology, Department of Internal Medicine, Shanghai Children’s Medical Center affiliated with Shanghai Jiaotong University School of Medicine, Shanghai 200127, China
| | - Jinwook Shin
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710
| | - Danli Xie
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710
- School of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Hongxia Wang
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710
- Laboratory Medicine Center, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Jimin Gao
- School of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Xiao-Ping Zhong
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710
- Department of Immunology, Duke University Medical Center, Durham, NC 27710
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12
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Ingram RJ, Harris A, Ascough S, Metan G, Doganay M, Ballie L, Williamson ED, Dyson H, Robinson JH, Sriskandan S, Altmann DM. Exposure to anthrax toxin alters human leucocyte expression of anthrax toxin receptor 1. Clin Exp Immunol 2013; 173:84-91. [PMID: 23607659 DOI: 10.1111/cei.12090] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2013] [Indexed: 12/12/2022] Open
Abstract
Anthrax is a toxin-mediated disease, the lethal effects of which are initiated by the binding of protective antigen (PA) with one of three reported cell surface toxin receptors (ANTXR). Receptor binding has been shown to influence host susceptibility to the toxins. Despite this crucial role for ANTXR in the outcome of disease, and the reported immunomodulatory consequence of the anthrax toxins during infection, little is known about ANTXR expression on human leucocytes. We characterized the expression levels of ANTXR1 (TEM8) on human leucocytes using flow cytometry. In order to assess the effect of prior toxin exposure on ANTXR1 expression levels, leucocytes from individuals with no known exposure, those exposed to toxin through vaccination and convalescent individuals were analysed. Donors could be defined as either 'low' or 'high' expressers based on the percentage of ANTXR1-positive monocytes detected. Previous exposure to toxins appears to modulate ANTXR1 expression, exposure through active infection being associated with lower receptor expression. A significant correlation between low receptor expression and high anthrax toxin-specific interferon (IFN)-γ responses was observed in previously infected individuals. We propose that there is an attenuation of ANTXR1 expression post-infection which may be a protective mechanism that has evolved to prevent reinfection.
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Affiliation(s)
- R J Ingram
- Section of Infectious Diseases and Immunity, Department of Medicine Imperial College, Hammersmith Hospital, London
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13
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Toxin inhibition of antimicrobial factors induced by Bacillus anthracis peptidoglycan in human blood. Infect Immun 2013; 81:3693-702. [PMID: 23876807 DOI: 10.1128/iai.00709-13] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Here, we describe the capacity of Bacillus anthracis peptidoglycan (BaPGN) to trigger an antimicrobial response in human white blood cells (WBCs). Analysis of freshly isolated human blood cells found that monocytes and neutrophils, but not B and T cells, were highly responsive to BaPGN and produced a variety of cytokines and chemokines. This BaPGN-induced response was suppressed by anthrax lethal toxin (LT) and edema toxin (ET), with the most pronounced effect on human monocytes, and this corresponded with the higher levels of anthrax toxin receptor 1 (ANTXR1) in these cells than in neutrophils. The supernatant from BaPGN-treated cells altered the growth of B. anthracis Sterne, and this effect was blocked by LT, but not by ET. An FtsX mutant of B. anthracis known to be resistant to the antimicrobial effects of interferon-inducible Glu-Leu-Arg (ELR)-negative CXC chemokines was not affected by the BaPGN-induced antimicrobial effects. Collectively, these findings describe a system in which BaPGN triggers expression of antimicrobial factors in human WBCs and reveal a distinctive role, not shared with ET, in LT's capacity to suppress this response.
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Joshi SK, Lang ML. Fine tuning a well-oiled machine: Influence of NK1.1 and NKG2D on NKT cell development and function. Int Immunopharmacol 2013; 17:260-6. [PMID: 23800654 DOI: 10.1016/j.intimp.2013.05.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 05/10/2013] [Accepted: 05/24/2013] [Indexed: 01/06/2023]
Abstract
Natural killer T cells (NKT) represent a group of CD1d-restricted T-lineage cells that provide a functional interface between innate and adaptive immune responses in infectious disease, cancer, allergy and autoimmunity. There have been remarkable advances in understanding the molecular events that underpin NKT development in the thymus and in the complex array of functions in the periphery. Most functional studies have focused on activation of T cell antigen receptors expressed by NKT cells and their responses to CD1d presentation of glycolipid and related antigens. Receiving less attention has been several molecules that are hallmarks of Natural Killer (NK) cells, but nonetheless expressed by NKT cells. These include several activating and inhibitory receptors that may fine-tune NKT development and survival, as well as activation via antigen receptors. Herein, we review the possible roles of the NK1.1 and NKG2D receptors in regulating development and function of NKT cells in health and disease. We suggest that pharmacological alteration of NKT activity should consider the potential complexities commensurate with NK1.1 and NKG2D expression.
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Affiliation(s)
- Sunil K Joshi
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
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15
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Anthrax lethal toxin and the induction of CD4 T cell immunity. Toxins (Basel) 2012; 4:878-99. [PMID: 23162703 PMCID: PMC3496994 DOI: 10.3390/toxins4100878] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 10/08/2012] [Accepted: 10/10/2012] [Indexed: 12/27/2022] Open
Abstract
Bacillus anthracis secretes exotoxins which act through several mechanisms including those that can subvert adaptive immunity with respect both to antigen presenting cell and T cell function. The combination of Protective Antigen (PA) and Lethal Factor (LF) forming Lethal Toxin (LT), acts within host cells to down-regulate the mitogen activated protein kinase (MAPK) signaling cascade. Until recently the MAPK kinases were the only known substrate for LT; over the past few years it has become evident that LT also cleaves Nlrp1, leading to inflammasome activation and macrophage death. The predicted downstream consequences of subverting these important cellular pathways are impaired antigen presentation and adaptive immunity. In contrast to this, recent work has indicated that robust memory T cell responses to B. anthracis antigens can be identified following natural anthrax infection. We discuss how LT affects the adaptive immune response and specifically the identification of B. anthracis epitopes that are both immunogenic and protective with the potential for inclusion in protein sub-unit based vaccines.
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16
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Cleret-Buhot A, Mathieu J, Tournier JN, Quesnel-Hellmann A. Both lethal and edema toxins of Bacillus anthracis disrupt the human dendritic cell chemokine network. PLoS One 2012; 7:e43266. [PMID: 22937027 PMCID: PMC3427382 DOI: 10.1371/journal.pone.0043266] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 07/18/2012] [Indexed: 11/19/2022] Open
Abstract
Bacillus anthracis, the agent of anthrax, produces two main virulence factors: a capsule and two toxins. Both lethal toxin (LT) and edema toxin (ET) paralyze the immune defense system. Here, we analyze the effects of LT and ET on the capacity of human monocyte-derived dendritic cells (MoDC) to produce proinflammatory chemokines. We show that both toxins disrupt proinflammatory chemokine production. LT has more pronounced effects than ET on CXCL8 production, which is correlated with impaired recruitment of neutrophils in vitro. Finally, we show that both toxins also differentially disrupt IL-12p70, IL-10, and TNF-α production. Taken together, these results demonstrate that both B. anthracis toxins alter MoDC functions and the activation of the innate immune system.
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Affiliation(s)
| | | | | | - Anne Quesnel-Hellmann
- Unité Interactions Hôte-Agents Pathogènes, Département de Microbiologie, Institut de Recherche Biomédicale des Armées, La Tronche, France
- * E-mail:
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17
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Lowe DE, Glomski IJ. Cellular and physiological effects of anthrax exotoxin and its relevance to disease. Front Cell Infect Microbiol 2012; 2:76. [PMID: 22919667 PMCID: PMC3417473 DOI: 10.3389/fcimb.2012.00076] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 05/16/2012] [Indexed: 12/26/2022] Open
Abstract
Bacillus anthracis, the causative agent of anthrax, secretes a tri-partite exotoxin that exerts pleiotropic effects on the host. The purification of the exotoxin components, protective antigen, lethal factor, and edema factor allowed the rapid characterization of their physiologic effects on the host. As molecular biology matured, interest focused on the molecular mechanisms and cellular alterations induced by intoxication. Only recently have researchers begun to connect molecular and cellular knowledge back to the broader physiological effects of the exotoxin. This review focuses on the progress that has been made bridging molecular knowledge back to the exotoxin’s physiological effects on the host.
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Affiliation(s)
- David E Lowe
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia Health System, Charlottesville VA, USA
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18
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Veach RA, Zienkiewicz J, Collins RD, Hawiger J. Lethality in a murine model of pulmonary anthrax is reduced by combining nuclear transport modifier with antimicrobial therapy. PLoS One 2012; 7:e30527. [PMID: 22291977 PMCID: PMC3266913 DOI: 10.1371/journal.pone.0030527] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 12/22/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In the last ten years, bioterrorism has become a serious threat and challenge to public health worldwide. Pulmonary anthrax caused by airborne Bacillus anthracis spores is a life-threatening disease often refractory to antimicrobial therapy. Inhaled spores germinate into vegetative forms that elaborate an anti-phagocytic capsule along with potent exotoxins which disrupt the signaling pathways governing the innate and adaptive immune responses and cause endothelial cell dysfunction leading to vascular injury in the lung, hypoxia, hemorrhage, and death. METHODS/PRINCIPAL FINDINGS Using a murine model of pulmonary anthrax disease, we showed that a nuclear transport modifier restored markers of the innate immune response in spore-infected animals. An 8-day protocol of single-dose ciprofloxacin had no significant effect on mortality (4% survival) of A/J mice lethally infected with B. anthracis Sterne. Strikingly, mice were much more likely to survive infection (52% survival) when treated with ciprofloxacin and a cell-penetrating peptide modifier of host nuclear transport, termed cSN50. In B. anthracis-infected animals treated with antibiotic alone, we detected a muted innate immune response manifested by cytokines, tumor necrosis factor alpha (TNFα), interleukin (IL)-6, and chemokine monocyte chemoattractant protein-1 (MCP-1), while the hypoxia biomarker, erythropoietin (EPO), was greatly elevated. In contrast, cSN50-treated mice receiving ciprofloxacin demonstrated a restored innate immune responsiveness and reduced EPO level. Consistent with this improvement of innate immunity response and suppression of hypoxia biomarker, surviving mice in the combination treatment group displayed minimal histopathologic signs of vascular injury and a marked reduction of anthrax bacilli in the lungs. CONCLUSIONS We demonstrate, for the first time, that regulating nuclear transport with a cell-penetrating modifier provides a cytoprotective effect, which enables the host's immune system to reduce its susceptibility to lethal B. anthracis infection. Thus, by combining a nuclear transport modifier with antimicrobial therapy we offer a novel adjunctive measure to control florid pulmonary anthrax disease.
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Affiliation(s)
- Ruth Ann Veach
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Jozef Zienkiewicz
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Robert D. Collins
- Department of Pathology, Vanderbilt University School of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Jacek Hawiger
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- * E-mail:
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19
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Klezovich-Bénard M, Corre JP, Jusforgues-Saklani H, Fiole D, Burjek N, Tournier JN, Goossens PL. Mechanisms of NK cell-macrophage Bacillus anthracis crosstalk: a balance between stimulation by spores and differential disruption by toxins. PLoS Pathog 2012; 8:e1002481. [PMID: 22253596 PMCID: PMC3257302 DOI: 10.1371/journal.ppat.1002481] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 11/28/2011] [Indexed: 01/08/2023] Open
Abstract
NK cells are important immune effectors for preventing microbial invasion and dissemination, through natural cytotoxicity and cytokine secretion. Bacillus anthracis spores can efficiently drive IFN-γ production by NK cells. The present study provides insights into the mechanisms of cytokine and cellular signaling that underlie the process of NK-cell activation by B. anthracis and the bacterial strategies to subvert and evade this response. Infection with non-toxigenic encapsulated B. anthracis induced recruitment of NK cells and macrophages into the mouse draining lymph node. Production of edema (ET) or lethal (LT) toxin during infection impaired this cellular recruitment. NK cell depletion led to accelerated systemic bacterial dissemination. IFN-γ production by NK cells in response to B. anthracis spores was: i) contact-dependent through RAE-1-NKG2D interaction with macrophages; ii) IL-12, IL-18, and IL-15-dependent, where IL-12 played a key role and regulated both NK cell and macrophage activation; and iii) required IL-18 for only an initial short time window. B. anthracis toxins subverted both NK cell essential functions. ET and LT disrupted IFN-γ production through different mechanisms. LT acted both on macrophages and NK cells, whereas ET mainly affected macrophages and did not alter NK cell capacity of IFN-γ secretion. In contrast, ET and LT inhibited the natural cytotoxicity function of NK cells, both in vitro and in vivo. The subverting action of ET thus led to dissociation in NK cell function and blocked natural cytotoxicity without affecting IFN-γ secretion. The high efficiency of this process stresses the impact that this toxin may exert in anthrax pathogenesis, and highlights a potential usefulness for controlling excessive cytotoxic responses in immunopathological diseases. Our findings therefore exemplify the delicate balance between bacterial stimulation and evasion strategies. This highlights the potential implication of the crosstalk between host innate defences and B. anthracis in initial anthrax control mechanisms. NK cells are important immune effectors that perform a surveillance task and react to transformed, stressed, and virally infected cells. They represent a first-line defence against cancer and pathogen invasion. Different pathogens trigger distinct NK-cell activation pathways. The Bacillus anthracis spore is the highly resistant form that enters the host and provokes anthrax. This microbe kills through a combination of acute bacterial infection and devastating toxemia. In the present study, we characterise the crosstalk between NK cells and spores, as well as the strategies used by B. anthracis to evade initial control mechanisms and impact anthrax pathogenesis. Our findings exemplify the spores' property to efficiently drive a high production of IFN-γ by NK cells, as well as the complex pathways used for activation which require both cytokine and cellular signaling. B. anthracis subverts this response through its toxins by paralysing essential NK cell functions. Furthermore, edema toxin from B. anthracis blocks natural cytotoxicity without affecting IFN-γ secretion. The CyaA toxin of Bordetella pertussis possesses the same enzymatic activity and has a similar effect. The high efficiency of these toxins in blocking cytotoxicity in vivo implies possible exploitation of their subverting activity to modulate excessive cytotoxic responses in immunopathological diseases.
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MESH Headings
- Animals
- Bacillus anthracis/immunology
- Bacterial Toxins/pharmacology
- Cells, Cultured
- Female
- Homeostasis/drug effects
- Homeostasis/immunology
- Immunity, Cellular/drug effects
- Immunity, Cellular/immunology
- Killer Cells, Natural/drug effects
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Macrophage Activation/drug effects
- Macrophage Activation/immunology
- Macrophages/drug effects
- Macrophages/immunology
- Macrophages/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Receptor Cross-Talk/drug effects
- Receptor Cross-Talk/immunology
- Spores, Bacterial/immunology
- Spores, Bacterial/physiology
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Affiliation(s)
- Maria Klezovich-Bénard
- Laboratoire Pathogénie et Toxi-Infections Bactériennes, Institut Pasteur, Paris, France
- CNRS URA 2172, Paris, France
| | - Jean-Philippe Corre
- Laboratoire Pathogénie et Toxi-Infections Bactériennes, Institut Pasteur, Paris, France
- CNRS URA 2172, Paris, France
| | | | - Daniel Fiole
- Unité Interactions Hôte-Agents Pathogènes, Département de Microbiologie, Institut de Recherche Biomédicale des Armées, La Tronche, France
- Laboratoire Interdisciplinaire de Physique, UMR 5588 CNRS/Université Joseph Fourier, St-Martin-d'Hères, France
| | - Nick Burjek
- Laboratoire Pathogénie et Toxi-Infections Bactériennes, Institut Pasteur, Paris, France
- CNRS URA 2172, Paris, France
| | - Jean-Nicolas Tournier
- Unité Interactions Hôte-Agents Pathogènes, Département de Microbiologie, Institut de Recherche Biomédicale des Armées, La Tronche, France
- École du Val-de-Grâce, Paris, France
| | - Pierre L. Goossens
- Laboratoire Pathogénie et Toxi-Infections Bactériennes, Institut Pasteur, Paris, France
- CNRS URA 2172, Paris, France
- * E-mail:
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20
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Antibacterial role for natural killer cells in host defense to Bacillus anthracis. Infect Immun 2011; 80:234-42. [PMID: 22006566 DOI: 10.1128/iai.05439-11] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Natural killer (NK) cells have innate antibacterial activity that could be targeted for clinical interventions for infectious disease caused by naturally occurring or weaponized bacterial pathogens. To determine a potential role for NK cells in immunity to Bacillus anthracis, we utilized primary human and murine NK cells, in vitro assays, and in vivo NK cell depletion in a murine model of inhalational anthrax. Our results demonstrate potent antibacterial activity by human NK cells against B. anthracis bacilli within infected autologous monocytes. Surprisingly, NK cells also mediate moderate antibacterial effects on extracellular vegetative bacilli but do not have activity against extracellular or intracellular spores. The immunosuppressive anthrax lethal toxin impairs NK gamma interferon (IFN-γ) expression, but neither lethal nor edema toxin significantly alters the viability or cytotoxic effector function of NK cells. Compared to human NK cells, murine NK cells have a similar, though less potent, activity against intracellular and extracellular B. anthracis. The in vivo depletion of murine NK cells does not alter animal survival following intranasal infection with B. anthracis spores in our studies but significantly increases the bacterial load in the blood of infected animals. Our studies demonstrate that NK cells participate in the innate immune response against B. anthracis and suggest that immune modulation to augment NK cell function in early stages of anthrax should be further explored in animal models as a clinical intervention strategy.
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21
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Regulation of anthrax toxin-specific antibody titers by natural killer T cell-derived IL-4 and IFNγ. PLoS One 2011; 6:e23817. [PMID: 21858226 PMCID: PMC3157475 DOI: 10.1371/journal.pone.0023817] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Accepted: 07/27/2011] [Indexed: 11/19/2022] Open
Abstract
Activation of Natural Killer-like T cells (NKT) with the CD1d ligand α-GC leads to enhanced production of anthrax toxin protective Ag (PA)-neutralizing Abs, yet the underlying mechanism for this adjuvant effect is not known. In the current study we examined the role of Th1 and Th2 type responses in NKT-mediated enhancement of antibody responses to PA. First, the contribution of IL-4 and IFNγ to the production of PA-specific toxin-neutralizing Abs was examined. By immunizing C57Bl/6 controls IL-4−/− mice and IFNγ−/− mice and performing passive serum transfer experiments, it was observed that sera containing PA-specific IgG1, IgG2b and IgG2c neutralized toxin in vitro and conferred protection in vivo. Sera containing IgG2b and IgG2c neutralized toxin in vitro but were not sufficient for protection in vivo. Sera containing IgG1 and IgG2b neutralized toxin in vitro and conferred protection in vivo. IgG1 therefore emerged as a good correlate of protection. Next, C57Bl/6 mice were immunized with PA alone or PA plus a Th2-skewing α-GC derivative known as OCH. Neutralizing PA-specific IgG1 responses were modestly enhanced by OCH in C57Bl/6 mice. Conversely, IgG2b and IgG2c were considerably enhanced in PA/OCH-immunized IL-4−/− mice but did not confer protection. Finally, bone marrow chimeras were generated such that NKT cells were unable to express IL-4 or IFNγ. NKT-derived IL-4 was required for OCH-enhanced primary IgG1 responses but not recall responses. NKT-derived IL-4 and IFNγ also influenced primary and recall IgG2b and IgG2c titers. These data suggest targeted skewing of the Th2 response by α-GC derivatives can be exploited to optimize anthrax vaccination.
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22
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Paccani SR, Baldari CT. T cell targeting by anthrax toxins: two faces of the same coin. Toxins (Basel) 2011; 3:660-71. [PMID: 22069732 PMCID: PMC3202842 DOI: 10.3390/toxins3060660] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 06/03/2011] [Accepted: 06/07/2011] [Indexed: 12/24/2022] Open
Abstract
Bacillus anthracis, similar to other bacterial pathogens, has evolved effective immune evasion strategies to prolong its survival in the host, thus ensuring the unchecked spread of the infection. This function is subserved by lethal (LT) and edema (ET) toxins, two exotoxins produced by vegetative anthrax bacilli following germination of the spores. The structure of these toxins and the mechanism of cell intoxication are topics covered by other reviews in this issue. Here we shall discuss how B. anthracis uses LT and ET to suppress the immune defenses of the host, focusing on T lymphocytes, the key players in adaptive immunity. We shall also summarize recent findings showing that, depending on its concentration, ET has the ability not only to suppress T cell activation but also to promote the polarization of CD4(+) T cells to the Th2 and Th17 subsets, highlighting the potential use of this toxin as an immunomodulator.
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Affiliation(s)
- Silvia Rossi Paccani
- Department of Evolutionary Biology, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy;
- Novartis Vaccines, Via Fiorentina 1, 53100 Siena, Italy
- Author to whom correspondence should be addressed; or ; Tel.: +39-0577-234396; Fax: +39-0577-234476
| | - Cosima T. Baldari
- Department of Evolutionary Biology, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy;
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23
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Van Kaer L, Parekh VV, Wu L. Invariant NK T cells: potential for immunotherapeutic targeting with glycolipid antigens. Immunotherapy 2011; 3:59-75. [PMID: 21174558 DOI: 10.2217/imt.10.85] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Invariant NK T (iNKT) cells are a subset of T lymphocytes that recognize glycolipid antigens bound with the antigen-presenting molecule CD1d. iNKT cells have potent immunoregulatory activities that can promote or suppress immune responses during different pathological conditions. These immunoregulatory properties can be harnessed for therapeutic purposes with cognate glycolipid antigens, such as the marine sponge-derived glycosphingolipid α-galactosylceramide. Preclinical studies have shown substantial promise for iNKT cell-based treatments of infections, cancer and autoimmune and inflammatory diseases. Translation of these preclinical studies to the clinic, while faced with some obstacles, has already had some initial success. In this article, we review the immunodulatory activities of iNKT cells and the potential for developing iNKT cell-based prophylactic and curative therapies of human disease.
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Affiliation(s)
- Luc Van Kaer
- Department of Microbiology & Immunology, Vanderbilt University School of Medicine, Medical Center North, Room A-5301, 1161 21st Avenue South, Nashville, TN 37232-32363, USA.
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24
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Lang GA, Johnson AM, Devera TS, Joshi SK, Lang ML. Reduction of CD1d expression in vivo minimally affects NKT-enhanced antibody production but boosts B-cell memory. Int Immunol 2011; 23:251-60. [PMID: 21398691 DOI: 10.1093/intimm/dxq477] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The CD1d-binding glycolipid α-galactosylceramide exerts potent adjuvant effects on T-dependent humoral immunity. The mechanism is driven by cognate interaction between CD1d-expressing B cells and TCR-expressing type I CD1d-restricted NKT cells. Thus, far positive effects of alpha-galactosylceramide have been observed on initial and sustained antibody titers as well as B-cell memory. Following vaccination, each of these features is desirable, but good B-cell memory is of paramount importance for long-lived immunity. We therefore tested the hypothesis that CD1d expression in vivo differentially affects initial antibody titers versus B-cell memory responses. CD1d(+/+) and CD1d(+/-) mice were generated and immunized with antigen plus CD1d ligand before analysis of cytokine expression, CD40L expression, initial and longer term antibody responses and B-cell memory. As compared with CD1d(+/+) controls, CD1d(+/-) mice had equivalent numbers of total NKT cells, lower cytokine production, fewer CD40L-expressing NKT cells, lower initial antibody responses, similar long-term antibody responses and higher B-cell memory. Our data indicate that weak CD1d antigen presentation may facilitate good B-cell memory without compromising antibody responses. This work may impact vaccine design since over-stimulation of NKT cells at the time of vaccination may not lead to optimal B-cell memory.
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Affiliation(s)
- Gillian A Lang
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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Stuart JK, Bisch SP, Leon-Ponte M, Hayatsu J, Mazzuca DM, Vareki SM, Haeryfar SM. Negative modulation of invariant natural killer T cell responses to glycolipid antigens by p38 MAP kinase. Int Immunopharmacol 2010; 10:1068-76. [DOI: 10.1016/j.intimp.2010.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 05/19/2010] [Accepted: 06/07/2010] [Indexed: 12/21/2022]
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Van Kaer L, Parekh VV, Wu L. Invariant natural killer T cells: bridging innate and adaptive immunity. Cell Tissue Res 2010; 343:43-55. [PMID: 20734065 DOI: 10.1007/s00441-010-1023-3] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 07/13/2010] [Indexed: 02/08/2023]
Abstract
Cells of the innate immune system interact with pathogens via conserved pattern-recognition receptors, whereas cells of the adaptive immune system recognize pathogens through diverse, antigen-specific receptors that are generated by somatic DNA rearrangement. Invariant natural killer T (iNKT) cells are a subset of lymphocytes that bridge the innate and adaptive immune systems. Although iNKT cells express T cell receptors that are generated by somatic DNA rearrangement, these receptors are semi-invariant and interact with a limited set of lipid and glycolipid antigens, thus resembling the pattern-recognition receptors of the innate immune system. Functionally, iNKT cells most closely resemble cells of the innate immune system, as they rapidly elicit their effector functions following activation, and fail to develop immunological memory. iNKT cells can become activated in response to a variety of stimuli and participate in the regulation of various immune responses. Activated iNKT cells produce several cytokines with the capacity to jump-start and modulate an adaptive immune response. A variety of glycolipid antigens that can differentially elicit distinct effector functions in iNKT cells have been identified. These reagents have been employed to test the hypothesis that iNKT cells can be harnessed for therapeutic purposes in human diseases. Here, we review the innate-like properties and functions of iNKT cells and discuss their interactions with other cell types of the immune system.
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Affiliation(s)
- Luc Van Kaer
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Medical Center North, Room A-5301, 1161 21st Ave. South, Nashville, TN 37232-2363, USA.
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Key roles of dendritic cells in lung infection and improving anthrax vaccines. Trends Mol Med 2010; 16:303-12. [DOI: 10.1016/j.molmed.2010.04.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 04/20/2010] [Accepted: 04/22/2010] [Indexed: 12/21/2022]
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Anthrax lethal toxin impairs CD1d-mediated antigen presentation by targeting the extracellular signal-related kinase 1/2 mitogen-activated protein kinase pathway. Infect Immun 2010; 78:1859-63. [PMID: 20194602 DOI: 10.1128/iai.01307-09] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lethal toxin (LT) is a critical virulence factor of Bacillus anthracis and an important means by which this bacterium evades the host's immune system. In this study, we demonstrate that CD1d-expressing cells treated with LT have reduced CD1d-mediated antigen presentation. We earlier showed an important role for the mitogen-activated protein kinase extracellular signal-regulated kinase 1/2 (ERK1/2) in the regulation of CD1d-mediated antigen presentation, and we report here that LT impairs antigen presentation by CD1d in an ERK1/2-dependent manner. Similarly, LT and the ERK1/2 pathway-specific inhibitor U0126 caused a decrease in major histocompatibility complex (MHC) class II-mediated antigen presentation. Confocal microscopy analyses revealed altered intracellular distribution of CD1d and LAMP-1 in LT-treated cells, similar to the case for ERK1/2-inhibited cells. These results suggest that Bacillus anthracis has the ability to evade the host's innate immune system by reducing CD1d-mediated antigen presentation through targeting the ERK1/2 pathway.
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