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Srivastava P, Shukla A, Singh R, Kant R, Mishra N, Behera SP, Dwivedi GR, Yadav DK. Orientia tsutsugamushi: An Unusual Intracellular Bacteria-Adaptation Strategies, Available Antibiotics, and Alternatives for Treatment. Curr Microbiol 2024; 81:236. [PMID: 38907107 DOI: 10.1007/s00284-024-03754-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 05/28/2024] [Indexed: 06/23/2024]
Abstract
During evolution Orientia tsutsugamushi became a smarter obligate bacterium to establish as intracellular pathogens. O. tsutsugamushi is a human pathogenic bacterium responsible for 1 billion infections of scrub typhus. Several novel mechanisms make this bacterium unique (cell wall, genetic constitutions, secretion system, etc.). In 2007, O. tsutsugamushi Boryong was pioneer strain for whole-genome sequencing. But the fundamental biology of this bacterial cell is a mystery till date. The unusual biology makes this organism as model for host cell interaction. Only a few antibiotics are effective against this intracellular pathogen but emergence of less susceptibility toward antibiotics make the situation alarming. The review was captivated to highlight the unusual aspects of adaptation, antibiotics, and drugs beyond antibiotics.
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Affiliation(s)
- Prashansha Srivastava
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Aishwarya Shukla
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Rajeev Singh
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Rajni Kant
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Nalini Mishra
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Sthita P Behera
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Gaurav R Dwivedi
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India.
| | - Dharmendra K Yadav
- College of Pharmacy, Gachon University of Medicine and Science, Hambakmoeiro 191, Yeonsu-Gu, Incheon, 21924, Korea
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Liang Y, Wang H, Sun K, Sun J, Soong L. Lack of the IFN-γ signal leads to lethal Orientia tsutsugamushi infection in mice with skin eschar lesions. PLoS Pathog 2024; 20:e1012020. [PMID: 38743761 PMCID: PMC11125519 DOI: 10.1371/journal.ppat.1012020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 05/24/2024] [Accepted: 04/30/2024] [Indexed: 05/16/2024] Open
Abstract
Scrub typhus is an acute febrile disease due to Orientia tsutsugamushi (Ot) infection and can be life-threatening with organ failure, hemorrhage, and fatality. Yet, little is known as to how the host reacts to Ot bacteria at early stages of infection; no reports have addressed the functional roles of type I versus type II interferon (IFN) responses in scrub typhus. In this study, we used comprehensive intradermal (i.d.) inoculation models and two clinically predominant Ot strains (Karp and Gilliam) to uncover early immune events. Karp infection induced sequential expression of Ifnb and Ifng in inflamed skin and draining lymph nodes at days 1 and 3 post-infection. Using double Ifnar1-/-Ifngr1-/- and Stat1-/- mice, we found that deficiency in IFN/STAT1 signaling resulted in lethal infection with profound pathology and skin eschar lesions, which resembled to human scrub typhus. Further analyses demonstrated that deficiency in IFN-γ, but not IFN-I, resulted in impaired NK cell and macrophage activation and uncontrolled bacterial growth and dissemination, leading to metabolic dysregulation, excessive inflammatory cell infiltration, and exacerbated tissue damage. NK cells were found to be the major cellular source of innate IFN-γ, contributing to the initial Ot control in the draining lymph nodes. In vitro studies with dendritic cell cultures revealed a superior antibacterial effect offered by IFN-γ than IFN-β. Comparative in vivo studies with Karp- and Gilliam-infection revealed a crucial role of IFN-γ signaling in protection against progression of eschar lesions and Ot infection lethality. Additionally, our i.d. mouse models of lethal infection with eschar lesions are promising tools for immunological study and vaccine development for scrub typhus.
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Affiliation(s)
- Yuejin Liang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Hui Wang
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Keer Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
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Fromm L, Mehl J, Keller C. Orientia tsutsugamushi: A life between escapes. Microbiologyopen 2023; 12:e1380. [PMID: 37877457 PMCID: PMC10493369 DOI: 10.1002/mbo3.1380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 08/31/2023] [Indexed: 10/26/2023] Open
Abstract
The life cycle of the mite-borne, obligate intracellular pathogen Orientia tsutsugamushi (Ot), the causative agent of human scrub typhus, differs in many aspects from that of other members of the Rickettsiales order. Particularly, the nonlytic cellular exit of individual Ot bacteria at the plasma membrane closely resembles the budding of enveloped viruses but has only been rudimentarily studied at the molecular level. This brief article is focused on the current state of knowledge of escape events in the life cycle of Ot and highlights differences in strategies of other rickettsiae.
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Affiliation(s)
- Lea Fromm
- Institute of VirologyPhilipps University MarburgMarburgGermany
| | - Jonas Mehl
- Institute of VirologyPhilipps University MarburgMarburgGermany
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Gillespie JJ, Salje J. Orientia and Rickettsia: different flowers from the same garden. Curr Opin Microbiol 2023; 74:102318. [PMID: 37080115 DOI: 10.1016/j.mib.2023.102318] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 04/22/2023]
Abstract
Recent discoveries of basal extracellular Rickettsiales have illuminated divergent evolutionary paths to host dependency in later-evolving lineages. Family Rickettsiaceae, primarily comprised of numerous protist- and invertebrate-associated species, also includes human pathogens from two genera, Orientia and Rickettsia. Once considered sister taxa, these bacteria form distinct lineages with newly appreciated lifestyles and morphological traits. Contrasting other rickettsial human pathogens in Family Anaplasmataceae, Orientia and Rickettsia species do not reside in host-derived vacuoles and lack glycolytic potential. With only a few described mechanisms, strategies for commandeering host glycolysis to support cytosolic growth remain to be discovered. While regulatory systems for this unique mode of intracellular parasitism are unclear, conjugative transposons unique to Orientia and Rickettsia species provide insights that are critical for determining how these obligate intracellular pathogens overtake eukaryotic cytosol.
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Affiliation(s)
- Joseph J Gillespie
- Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, USA.
| | - Jeanne Salje
- Department of Biochemistry, Department of Pathology, and Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
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An Alternative Splicing Variant of the Mixed-Lineage Leukemia 5 Protein Is a Cellular Adhesion Receptor for ScaA of Orientia tsutsugamushi. mBio 2023; 14:e0154322. [PMID: 36541760 PMCID: PMC9973269 DOI: 10.1128/mbio.01543-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Scrub typhus is a mite-borne disease caused by the obligately intracellular bacterium Orientia tsutsugamushi. We previously demonstrated that ScaA, an autotransporter membrane protein of O. tsutsugamushi, is commonly shared in various genotypes and involved in adherence to host cells. Here, we identified a mixed-lineage leukemia 5 (MLL5) mammalian trithorax group protein as a host receptor that interacts with ScaA. MLL5, identified by yeast two-hybrid screening, is an alternative splicing variant of MLL5 (vMLL5) which contains 13 exons with additional intron sequences encoding a tentative transmembrane domain. Indeed, vMLL5 is expressed on the plasma membrane as well as in intracellular compartments in eukaryotic cells and colocalized with adherent O. tsutsugamushi. In addition, ScaA-expressing Escherichia coli showed significantly increased adherence to vMLL5-overexpressing cells compared with vector control cells. We mapped the C-terminal region of the passenger domain of ScaA as a ligand for vMLL5 and determined that the Su(var)3-9, Enhancer of zeste, Trithorax (SET) domain of MLL5 is an essential and sufficient motif for ScaA binding. We observed significant and specific inhibition of bacterial adhesion to host cells in competitive inhibition assays using the C-terminal fragment of ScaA or the SET domain of vMLL5. Moreover, immunization with the C-terminal fragment of ScaA provided neutralizing activity and protective immunity against lethal challenge with O. tsutsugamushi as efficiently as vaccination with the whole passenger domain of ScaA. These results indicate that vMLL5 is a novel cellular receptor for ScaA-mediated adhesion of O. tsutsugamushi and facilitates bacterial adhesion to host cells, thereby enhancing bacterial infection. IMPORTANCE O. tsutsugamushi is a mite-borne pathogen that causes scrub typhus. As an obligately intracellular pathogen, its adhesion to and invasion of host cells are critical steps for bacterial growth. However, the molecular basis of the bacterial ligand and host receptor interaction is poorly defined. Here, we identified a splicing variant of MLL5 (vMLL5) as a cellular adhesion receptor of ScaA, an outer membrane autotransporter protein of O. tsutsugamushi. We mapped the interacting domains in the bacterial ligand and host receptor and confirmed their functional interaction. In addition, immunization with the C-terminal region of ScaA, which involves an interaction with the SET domain of vMLL5, not only induces enhanced neutralizing antibodies but also provides protective immunity against lethal challenge with O. tsutsugamushi.
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Liang Y, Wang H, Gonzales C, Thiriot J, Sunyakumthorn P, Melby PC, Sun J, Soong L. CCR7/dendritic cell axis mediates early bacterial dissemination in Orientia tsutsugamushi-infected mice. Front Immunol 2022; 13:1061031. [PMID: 36618364 PMCID: PMC9813216 DOI: 10.3389/fimmu.2022.1061031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022] Open
Abstract
Scrub typhus is a life-threatening zoonosis caused by the obligate intracellular bacterium Orientia tsutsugamushi (Ot) that is transmitted by the infected larvae of trombiculid mites. However, the mechanism by which Ot disseminates from the bite site to visceral organs remains unclear; host innate immunity against bacterial dissemination and replication during early infection is poorly understood. In this study, by using an intradermal infection mouse model and fluorescent probe-labeled Ot, we assessed the dynamic pattern of innate immune cell responses at the inoculation site. We found that neutrophils were the first responders to Ot infection and migrated into the skin for bacterial uptake. Ot infection greatly induced neutrophil activation, and Ot-neutrophil interaction remarkably promoted cell death both in vitro and in vivo. Depletion of neutrophils did not alter bacterial dissemination in mice, as evidenced by similar bacterial burdens in the skin and draining lymph nodes (dLN) at day 3, as well as in the lungs and brains at day 14, as compared to the control mice. Instead, dendritic cells (DCs) and macrophages played a role as a Trojan horse and transmitted Ot from the skin into dLN. Importantly, the absence of homing receptor CCR7 or neutralization of its ligand, CCL21, significantly impaired DC migration, resulting in reduced bacterial burdens in dLN. Taken together, our study sheds light on a CCR7/dendritic cell-mediated mechanism of early Ot dissemination and provides new insights into therapeutic and vaccine development strategies for scrub typhus.
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Affiliation(s)
- Yuejin Liang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
| | - Hui Wang
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Casey Gonzales
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Joseph Thiriot
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Piyanate Sunyakumthorn
- Department of Veterinary Medicine, United States Army Medical Directorate, Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok, Thailand
| | - Peter C. Melby
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
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Orientia tsutsugamushi OtDUB Is Expressed and Interacts with Adaptor Protein Complexes during Infection. Infect Immun 2022; 90:e0046922. [PMID: 36374099 PMCID: PMC9753657 DOI: 10.1128/iai.00469-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Orientia tsutsugamushi is an etiologic agent of scrub typhus, a globally emerging rickettsiosis that can be fatal. The bacterium's obligate intracellular lifestyle requires its interaction with host eukaryotic cellular pathways. The proteins it employs to do so and their functions during infection are understudied. Recombinant versions of the recently characterized O. tsutsugamushi deubiquitylase (OtDUB) exhibit high-affinity ubiquitin binding, mediate guanine nucleotide exchange to activate Rho GTPases, bind clathrin adaptor protein complexes 1 and 2, and bind the phospholipid phosphatidylserine. Whether OtDUB is expressed and its function during O. tsutsugamushi infection have yet to be explored. Here, OtDUB expression, location, and interactome during infection were examined. O. tsutsugamushi transcriptionally and translationally expresses OtDUB throughout infection of epithelial, monocytic, and endothelial cells. Results from structured illumination microscopy, surface trypsinization of intact bacteria, and acetic acid extraction of non-integral membrane proteins indicate that OtDUB peripherally associates with the O. tsutsugamushi cell wall and is at least partially present on the bacterial surface. Analyses of the proteins with which OtDUB associates during infection revealed several known O. tsutsugamushi cell wall proteins and others. It also forms an interactome with adapter protein complex 2 and other endosomal membrane traffic regulators. This study documents the first interactors of OtDUB during O. tsutsugamushi infection and establishes a strong link between OtDUB and the host endocytic pathway.
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Panda S, Swain SK, Sahu BP, Sarangi R. Gene expression and involvement of signaling pathways during host-pathogen interplay in Orientia tsutsugamushi infection. 3 Biotech 2022; 12:180. [PMID: 35860421 PMCID: PMC9295102 DOI: 10.1007/s13205-022-03239-7] [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: 04/01/2022] [Accepted: 06/18/2022] [Indexed: 11/22/2022] Open
Abstract
Scrub typhus is a neglected tropical disease that affects one-third of the world’s population. The disease is caused by Orientia tsutsugamushi (OT), an obligate intracellular Gram-negative bacterium. OT efficiently escapes from the endosomal pathway after entering the host cell and replicates inside cytosol. OT infection promotes cellular autophagy, the autonomous defense mechanism unlike other bacteria. This study has discussed the bacterial invasion process through the extracellular matrix and the immune response activated by the bacterium within the hosts. Furthermore, we have emphasized the importance of extracellular matrix and their cross-talk with the immune cells, such as, macrophages, neutrophils, and dendritic cells followed by their inflammatory response. We have also put an insight into the host factors associated with signaling pathways during scrub typhus disease with a special focus on the OT-induced stress response, autophagy, apoptosis, and innate immunity. Multiple cytokines and chemokines play a significant role in activating different immune-related signaling pathways. Due to the presence of high antigenic diversity among strains, the signaling pathways during the host–pathogen interplay of OT with its host is very complicated. Thus, it hinders to mitigate the severity of the pandemic occurred by the respective pathogen. Our investigation will provide a useful guide to better understand the virulence and physiology of this intracellular pathogen which will lead towards a better therapeutic diagnosis and vaccine development.
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Affiliation(s)
- Subhasmita Panda
- Department of Pediatrics, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
| | - Subrat Kumar Swain
- Centre for Genomics and Biomedical Informatics, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
| | - Basanta Pravas Sahu
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore 453552 India
| | - Rachita Sarangi
- Department of Pediatrics, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
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Chen Y, Cao B, Zheng W, Sun Y, Xu T. eIF3k inhibits NF-κB signaling by targeting MyD88 for ATG5-mediated autophagic degradation in teleost fish. J Biol Chem 2022; 298:101730. [PMID: 35176284 PMCID: PMC8914388 DOI: 10.1016/j.jbc.2022.101730] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/02/2022] [Accepted: 02/08/2022] [Indexed: 12/18/2022] Open
Abstract
Optimal activation of NF-κB signaling is crucial for the initiation of inflammatory responses and eliminating invading bacteria. Bacteria have likewise evolved the ability to evade immunity; however, mechanisms by which bacteria dysregulate host NF-κB signaling are unclear. In this study, we identify eukaryotic translation initiation factor eIF3k, a nonessential member of the eIF3 translation initiation complex, as a suppressor of the NF-κB pathway. Mechanistically, we show that eIF3k expression induced by Vibrio harveyi enhances E3 ligase Nrdp1-mediated K27-linked ubiquitination of MyD88, an upstream regulator of NF-κB pathway activation. Furthermore, we show that eIF3k acts as a bridge linking ubiquitin-tagged MyD88 and ATG5, an important mediator of autophagy. We demonstrate that the MyD88-eIF3k-ATG5 complex is transported to the autophagosome for degradation, and that innate immune signaling is subsequently terminated and does not attack invading V. harveyi. Therefore, our study identifies eIF3k as a specific inhibitor of the MyD88-dependent NF-κB pathway and suggests that eIF3k may act as a selective autophagic receptor that synergizes with ATG5 to promote the autophagic degradation of MyD88, which helps V. harveyi to evade innate immunity. We conclude that V. harveyi can manipulate a host's autophagy process to evade immunity in fish and also provide a new perspective on mammalian resistance to bacterial invasion.
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Affiliation(s)
- Ya Chen
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Baolan Cao
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Weiwei Zheng
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Yuena Sun
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, Shanghai, China; National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai, China
| | - Tianjun Xu
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, Shanghai, China; National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai, China.
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Han YH, Hwang JH, Lee CS. Xerostomia in a patient with scrub typhus. Radiol Case Rep 2021; 16:2754-2756. [PMID: 34367389 PMCID: PMC8326562 DOI: 10.1016/j.radcr.2021.06.066] [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: 06/07/2021] [Revised: 06/20/2021] [Accepted: 06/21/2021] [Indexed: 11/26/2022] Open
Abstract
Scrub typhus is an acute febrile disease caused by the intracellular organism Orientia tsutsugamushi. The main pathogenesis is focal or disseminated multi-organ vasculitis caused by the infection of endothelial cells and the perivascular infiltration of leukocytes. Many studies have reported interstitial pneumonia, cholecystitis, pancreatitis, and meningoencephalitis in scrub typhus. However, there is no report about sialoadenitis in a patient with scrub typhus. A 79-year-old man was admitted to the emergency room due to a high fever, headache, and myalgia. Scrub typhus was confirmed based on the indirect immunofluorescence assay and the nested polymerase chain reaction. He suffered from severe dry mouth and underwent Tc-99m pertechnetate salivary scintigraphy. While the radiopharmeceutical uptake of the bilateral parotid and submandibular glands was within normal range, salivary excretion into the oral cavity was markedly decreased. After the proper antibiotic treatment, salivary scintigraphy was performed again. Radioactivity in the oral cavity was increased and the ejection fraction (%) after using sialogogue was also improved to the normal range. As far as we know, this is the first report to show salivary scintigraphy of a patient with scrub typhus. By using a Tc-99m pertechnetate salivary scintigraphy, we found that the excretory function of salivary glands was markedly decreased, while the uptake ability was preserved in scrub typhus, unlike Sjögren's syndrome and radiation-induced xerostomia. Salivary scintigraphy presents dry mouth objectively and provides quantitative values as well. Salivary scintigraphy could contribute to the assessment of sialoadenitis before and after treatment of scrub typhus.
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Affiliation(s)
- Yeon-Hee Han
- Department of Nuclear Medicine, Molecular Imaging & Therapeutic Medicine Research Center, Research Institute of Clinical Medicine of Jeonbuk National University - Biomedical Research Institute of Jeonbuk National University Hospital, Jeonbuk National University Medical School and Hospital, Jeonju, Jeonbuk, Republic of Korea
| | - Joo-Hee Hwang
- Department of Internal Medicine, Research Institute of Clinical Medicine of Jeonbuk National University -Biomedical Research Institute of Jeonbuk National University Hospital, Jeonbuk National University Medical School and Hospital, 567 Baekje-daero, Jeonju, Jeonbuk 54907, Republic of Korea
| | - Chang-Seop Lee
- Department of Internal Medicine, Research Institute of Clinical Medicine of Jeonbuk National University -Biomedical Research Institute of Jeonbuk National University Hospital, Jeonbuk National University Medical School and Hospital, 567 Baekje-daero, Jeonju, Jeonbuk 54907, Republic of Korea
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Orientia tsutsugamushi Nucleomodulin Ank13 Exploits the RaDAR Nuclear Import Pathway To Modulate Host Cell Transcription. mBio 2021; 12:e0181621. [PMID: 34340535 PMCID: PMC8406279 DOI: 10.1128/mbio.01816-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Orientia tsutsugamushi is the etiologic agent of scrub typhus, the deadliest of all diseases caused by obligate intracellular bacteria. Nucleomodulins, bacterial effectors that dysregulate eukaryotic transcription, are being increasingly recognized as key virulence factors. How they translocate into the nucleus and their functionally essential domains are poorly defined. We demonstrate that Ank13, an O. tsutsugamushi effector conserved among clinical isolates and expressed during infection, localizes to the nucleus in an importin β1-independent manner. Rather, Ank13 nucleotropism requires an isoleucine at the thirteenth position of its fourth ankyrin repeat, consistent with utilization of eukaryotic RaDAR (RanGDP-ankyrin repeats) nuclear import. RNA-seq analyses of cells expressing green fluorescent protein (GFP)-tagged Ank13, nucleotropism-deficient Ank13I127R, or Ank13ΔF-box, which lacks the F-box domain essential for interacting with SCF ubiquitin ligase, revealed Ank13 to be a nucleomodulin that predominantly downregulates transcription of more than 2,000 genes. Its ability to do so involves its nucleotropism and F-box in synergistic and mutually exclusive manners. Ank13 also acts in the cytoplasm to dysregulate smaller cohorts of genes. The effector’s toxicity in yeast heavily depends on its F-box and less so on its nucleotropism. Genes negatively regulated by Ank13 include those involved in the inflammatory response, transcriptional control, and epigenetics. Importantly, the majority of genes that GFP-Ank13 most strongly downregulates are quiescent or repressed in O. tsutsugamushi-infected cells when Ank13 expression is strongest. Ank13 is the first nucleomodulin identified to coopt RaDAR and a multifaceted effector that functions in the nucleus and cytoplasm via F-box-dependent and -independent mechanisms to globally reprogram host cell transcription.
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Comparison of Lethal and Nonlethal Mouse Models of Orientia tsutsugamushi Infection Reveals T-Cell Population-Associated Cytokine Signatures Correlated with Lethality and Protection. Trop Med Infect Dis 2021; 6:tropicalmed6030121. [PMID: 34287349 PMCID: PMC8293330 DOI: 10.3390/tropicalmed6030121] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/25/2021] [Accepted: 06/30/2021] [Indexed: 11/19/2022] Open
Abstract
The antigenic diversity of Orientia tsutsugamushi as well as the interstrain difference(s) associated with virulence in mice impose the necessity to dissect the host immune response. In this study we compared the host response in lethal and non-lethal murine models of O. tsutsugamushi infection using the two strains, Karp (New Guinea) and Woods (Australia). The models included the lethal model: Karp intraperitoneal (IP) challenge; and the nonlethal models: Karp intradermal (ID), Woods IP, and Woods ID challenges. We monitored bacterial trafficking to the liver, lung, spleen, kidney, heart, and blood, and seroconversion during the 21-day challenge. Bacterial trafficking to all organs was observed in both the lethal and nonlethal models of infection, with significant increases in average bacterial loads observed in the livers and hearts of the lethal model. Multicolor flow cytometry was utilized to analyze the CD4+ and CD8+ T cell populations and their intracellular production of the cytokines IFNγ, TNF, and IL2 (single, double, and triple combinations) associated with both the lethal and nonlethal murine models of infection. The lethal model was defined by a cytokine signature of double- (IFNγ-IL2) and triple-producing (IL2-TNF-IFNγ) CD4+ T-cell populations; no multifunctional signature was identified in the CD8+ T-cell populations associated with the lethal model. In the nonlethal model, the cytokine signature was predominated by CD4+ and CD8+ T-cell populations associated with single (IL2) and/or double (IL2-TNF) populations of producers. The cytokine signatures associated with our lethal model will become depletion targets in future experiments; those signatures associated with our nonlethal model are hypothesized to be related to the protective nature of the nonlethal challenges.
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Kang SJ, Park KJ, Jin HM, Cho YN, Oh TH, Kim SE, Kim UJ, Park KH, Jung SI, Kim TO, Kim HS, Jo YG, Ju JK, Kee SJ, Park YW. Circulating Plasmacytoid and Conventional Dendritic Cells Are Numerically and Functionally Deficient in Patients With Scrub Typhus. Front Immunol 2021; 12:700755. [PMID: 34276693 PMCID: PMC8281928 DOI: 10.3389/fimmu.2021.700755] [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: 04/26/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
Background Dendritic cells (DCs) are specialized antigen-presenting cells known to bridge innate and adaptive immune reactions. However, the relationship between circulating DCs and Orientia tsutsugamushi infection is unclear. Therefore, this study aimed to examine the level and function of plasmacytoid DCs (pDCs) and conventional DCs (cDCs), two subsets of circulating DCs, in scrub typhus patients. Methods The study included 35 scrub typhus patients and 35 healthy controls (HCs). pDC and cDC levels, CD86 and CD274 expression, and cytokine levels were measured using flow cytometry. Results Circulating pDC and cDC levels were found to be significantly reduced in scrub typhus patients, which were correlated with disease severity. The patients displayed increased percentages of CD86+ pDCs, CD274+ pDCs, and CD274+ cDCs in the peripheral blood. The alterations in the levels and surface phenotypes of pDCs and cDCs were recovered in the remission state. In addition, the production of interferon (IFN)-α and tumor necrosis factor (TNF)-α by circulating pDCs, and interleukin (IL)-12 and TNF-α by circulating cDCs was reduced in scrub typhus patients. Interestingly, our in vitro experiments showed that the percentages of CD86+ pDCs, CD274+ pDCs, and CD274+ cDCs were increased in cultures treated with cytokines including IFN-γ, IL-12, and TNF-α. Conclusions This study demonstrates that circulating pDCs and cDCs are numerically deficient and functionally impaired in scrub typhus patients. In addition, alterations in the expression levels of surface phenotypes of pDCs and cDCs could be affected by pro-inflammatory cytokines.
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Affiliation(s)
- Seung-Ji Kang
- Department of Infectious Diseases, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Ki-Jeong Park
- Department of Rheumatology, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Hye-Mi Jin
- Department of Rheumatology, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Young-Nan Cho
- Department of Rheumatology, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Tae Hoon Oh
- Department of Infectious Diseases, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Seong Eun Kim
- Department of Infectious Diseases, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Uh Jin Kim
- Department of Infectious Diseases, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Kyung-Hwa Park
- Department of Infectious Diseases, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Sook-In Jung
- Department of Infectious Diseases, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Tae-Ok Kim
- Department of Pulmonology, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Hyo Shin Kim
- Department of Surgery, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Young-Goun Jo
- Department of Surgery, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Jae Kyun Ju
- Department of Surgery, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Seung-Jung Kee
- Department of Laboratory Medicine, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Yong-Wook Park
- Department of Rheumatology, Chonnam National University Medical School and Hospital, Gwangju, South Korea
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Mandage R, Kaur C, Pramanik A, Kumar V, Kodan P, Singh A, Saha S, Pandey S, Wig N, Pandey RM, Soneja M, Acharya P. Association of Dengue Virus and Leptospira Co-Infections with Malaria Severity. Emerg Infect Dis 2021; 26:1645-1653. [PMID: 32687019 PMCID: PMC7392441 DOI: 10.3201/eid2608.191214] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Plasmodium infections are co-endemic with infections caused by other agents of acute febrile illnesses, such as dengue virus (DENV), chikungunya virus, Leptospira spp., and Orientia tsutsugamushi. However, co-infections may influence disease severity, treatment outcomes, and development of drug resistance. When we analyzed cases of acute febrile illness at the All India Institute of Medical Sciences, New Delhi, India, from July 2017 through September 2018, we found that most patients with malaria harbored co-infections (Plasmodium mixed species and other pathogens). DENV was the most common malaria co-infection (44% of total infections). DENV serotype 4 was associated with mild malaria, and Leptospira was associated with severe malaria. We also found the presence of P. knowlesi in our study population. Therefore, in areas with a large number of severe malaria cases, diagnostic screening for all 4 DENV serotypes, Leptospira, and all Plasmodium species should be performed.
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15
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Patterson LL, Byerly CD, McBride JW. Anaplasmataceae: Dichotomous Autophagic Interplay for Infection. Front Immunol 2021; 12:642771. [PMID: 33912170 PMCID: PMC8075259 DOI: 10.3389/fimmu.2021.642771] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/15/2021] [Indexed: 12/19/2022] Open
Abstract
Autophagy is a vital conserved degradative process that maintains cellular homeostasis by recycling or eliminating dysfunctional cellular organelles and proteins. More recently, autophagy has become a well-recognized host defense mechanism against intracellular pathogens through a process known as xenophagy. On the host-microbe battlefield many intracellular bacterial pathogens have developed the ability to subvert xenophagy to establish infection. Obligately intracellular bacterial pathogens of the Anaplasmataceae family, including Ehrlichia chaffeensis, Anaplasma phaogocytophilium and Orientia tsutsugamushi have developed a dichotomous strategy to exploit the host autophagic pathway to obtain nutrients while escaping lysosomal destruction for intracellular survival within the host cell. In this review, the recent findings regarding how these master manipulators engage and inhibit autophagy for infection are explored. Future investigation to understand mechanisms used by Anaplasmataceae to exploit autophagy may advance novel antimicrobial therapies and provide new insights into how intracellular microbes exploit autophagy to survive.
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Affiliation(s)
- LaNisha L Patterson
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Caitlan D Byerly
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jere W McBride
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States.,Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, United States.,Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, United States.,Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
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16
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Salje J. Cells within cells: Rickettsiales and the obligate intracellular bacterial lifestyle. Nat Rev Microbiol 2021; 19:375-390. [PMID: 33564174 DOI: 10.1038/s41579-020-00507-2] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2020] [Indexed: 01/01/2023]
Abstract
The Rickettsiales are a group of obligate intracellular vector-borne Gram-negative bacteria that include many organisms of clinical and agricultural importance, including Anaplasma spp., Ehrlichia chaffeensis, Wolbachia, Rickettsia spp. and Orientia tsutsugamushi. This Review provides an overview of the current state of knowledge of the biology of these bacteria and their interactions with host cells, with a focus on pathogenic species or those that are otherwise important for human health. This includes a description of rickettsial genomics, bacterial cell biology, the intracellular lifestyles of Rickettsiales and the mechanisms by which they induce and evade the innate immune response.
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Affiliation(s)
- Jeanne Salje
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Public Health Research Institute, Rutgers University, Newark, NJ, USA.
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17
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Jiang L, Belinskaya T, Zhang Z, Chan TC, Ching WM, Chao CC. Regulation of Serum Exosomal MicroRNAs in Mice Infected with Orientia tsutsugamushi. Microorganisms 2020; 9:microorganisms9010080. [PMID: 33396228 PMCID: PMC7823836 DOI: 10.3390/microorganisms9010080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 12/25/2020] [Indexed: 12/21/2022] Open
Abstract
Exosomes are small extracellular vesicles that carry proteins, lipids, and nucleic acids. They are circulated in many body fluids and play an important role in intercellular communications. MicroRNAs (miRNAs), as major components of exosomes, are often regulated in many diseases including bacterial and viral infections. Functionally, exosome-carried miRNAs interact with various immune cells and affect their behavior. Little is known whether exosomal miRNAs are regulated during scrub typhus, a potentially lethal infection caused by intracellular bacteria, Orientiatsutsugamushi. In the present study, we utilized a scrub typhus mouse model and collected serum at various time points post infection. A custom quantitative PCR array covering 92 murine miRNAs was used to profile serum exosomal miRNAs. A total of 12 miRNAs were found to be significantly up- or down-regulated at least at one time point post infection when compared to uninfected animals. Further analysis identified multiple miRNAs in the let-7 family that were consistently down-regulated at early and late phase of infection. Functionally, serum exosomes isolated from infected mice displayed strong proinflammatory effect when incubated with bone marrow-derived macrophages. Our data revealed dynamic regulations of serum exosomal miRNA during scrub typhus infection, which could significantly influence host immune responses and disease outcome.
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Affiliation(s)
- Le Jiang
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD 20910, USA; (L.J.); (T.B.); (Z.Z.); (T.-C.C.); (W.-M.C.)
| | - Tatyana Belinskaya
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD 20910, USA; (L.J.); (T.B.); (Z.Z.); (T.-C.C.); (W.-M.C.)
| | - Zhiwen Zhang
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD 20910, USA; (L.J.); (T.B.); (Z.Z.); (T.-C.C.); (W.-M.C.)
| | - Teik-Chye Chan
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD 20910, USA; (L.J.); (T.B.); (Z.Z.); (T.-C.C.); (W.-M.C.)
| | - Wei-Mei Ching
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD 20910, USA; (L.J.); (T.B.); (Z.Z.); (T.-C.C.); (W.-M.C.)
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Chien-Chung Chao
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD 20910, USA; (L.J.); (T.B.); (Z.Z.); (T.-C.C.); (W.-M.C.)
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
- Correspondence:
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18
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Kala D, Gupta S, Nagraik R, Verma V, Thakur A, Kaushal A. Diagnosis of scrub typhus: recent advancements and challenges. 3 Biotech 2020; 10:396. [PMID: 32834918 PMCID: PMC7431554 DOI: 10.1007/s13205-020-02389-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Scrub typhus is a mite-borne, acute febrile illness caused by the bacterium Orientia tsutsugamushi. It is a re-emerging infectious disease of the tsutsugamushi triangle. Scrub typhus is transmitted through bites of contaminated chiggers (larval stage). Diagnosis of scrub typhus is challenging as its symptoms mimic with other acute febrile illnesses. Several methods are effectual for diagnosis of scrub typhus that includes enzyme-linked immunosorbent assay (ELISA), immunofluorescence assay (IFA), immunochromatographic test (ICT), Weil-Felix, polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP). Weil-Felix test was initially used for the diagnosis of scrub typhus in underdeveloped countries but not preferred due to a lack of both specificity and sensitivity. Other immuno-based methods like IFA and ELISA are most outrank for detection of scrub typhus due to their higher sensitivity and specificity, but not vigorous to lay bare the infection at early stages and need the convalescent sampling for verification of positive samples. On another deed, PCR based methods becoming acceptable over era due to its dexterity of early-stage diagnosis with higher specificity and sensitivity but lack its applicability in circumstances of scrub typhus due to the variegated genetic makeup of Orientia tsutsugamushi among its serotypes. The present review focused on various detection methods along with their advantages and disadvantages used in the diagnosis of scrub typhus. A comparison between available methods of diagnosis with challenges in the detection of scrub typhus is also summarized.
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Affiliation(s)
- Deepak Kala
- Amity Center of Nanotechnology, Amity University, Haryana, 122413 India
| | | | | | | | - Atul Thakur
- Amity Center of Nanotechnology, Amity University, Haryana, 122413 India
| | - Ankur Kaushal
- Amity Center of Nanotechnology, Amity University, Haryana, 122413 India
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19
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Kim HI, Ha NY, Kim G, Min CK, Kim Y, Yen NTH, Choi MS, Cho NH. Immunization with a recombinant antigen composed of conserved blocks from TSA56 provides broad genotype protection against scrub typhus. Emerg Microbes Infect 2019; 8:946-958. [PMID: 31237478 PMCID: PMC6598529 DOI: 10.1080/22221751.2019.1632676] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Scrub typhus is an acute febrile disease caused by Orientia tsutsugamushi infection. Despite the wide range of approaches explored during the last seventy years, an effective prophylactic vaccine is not yet available. Here, we developed a novel recombinant antigen derived from conserved regions of 56 kDa type-specific antigen (TSA56), a major outer membrane protein responsible for genetic heterogeneity and antigenicity, and evaluated it as a protective vaccine antigen. Our findings demonstrate that immunization with conserved blocks of TSA56 (cTSA56) not only provides protective immunity against lethal challenges with the homologous genotype, but also confers significantly better protection against heterologous genotypes than TSA56. Adoptive transfer of CD4+ or CD8+ T cells from immunized mice provided significantly enhanced protection against lethal challenge, whereas immune B cells failed to do so, indicating that cellular immunity against the conserved epitopes plays a protective role. Moreover, immunization with a 10-mer peptide mixture, screened from CD8+ T cell epitopes within the conserved region of TSA56, provided enhanced protection against lethal challenge with O. tsutsugamushi. Therefore, this novel recombinant antigen is a promising candidate for scrub typhus vaccine against a wide range of O. tsutsugamushi genotypes.
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Affiliation(s)
- Hong-Il Kim
- a Department of Microbiology and Immunology , Seoul National University College of Medicine , Seoul , Republic of Korea.,b Department of Biomedical Sciences , Seoul National University College of Medicine , Seoul , Republic of Korea
| | - Na-Young Ha
- a Department of Microbiology and Immunology , Seoul National University College of Medicine , Seoul , Republic of Korea.,b Department of Biomedical Sciences , Seoul National University College of Medicine , Seoul , Republic of Korea
| | - Gwanghun Kim
- a Department of Microbiology and Immunology , Seoul National University College of Medicine , Seoul , Republic of Korea.,b Department of Biomedical Sciences , Seoul National University College of Medicine , Seoul , Republic of Korea
| | - Chan-Ki Min
- a Department of Microbiology and Immunology , Seoul National University College of Medicine , Seoul , Republic of Korea.,b Department of Biomedical Sciences , Seoul National University College of Medicine , Seoul , Republic of Korea
| | - Yuri Kim
- a Department of Microbiology and Immunology , Seoul National University College of Medicine , Seoul , Republic of Korea.,b Department of Biomedical Sciences , Seoul National University College of Medicine , Seoul , Republic of Korea
| | - Nguyen Thi Hai Yen
- a Department of Microbiology and Immunology , Seoul National University College of Medicine , Seoul , Republic of Korea.,b Department of Biomedical Sciences , Seoul National University College of Medicine , Seoul , Republic of Korea
| | - Myung-Sik Choi
- a Department of Microbiology and Immunology , Seoul National University College of Medicine , Seoul , Republic of Korea
| | - Nam-Hyuk Cho
- a Department of Microbiology and Immunology , Seoul National University College of Medicine , Seoul , Republic of Korea.,b Department of Biomedical Sciences , Seoul National University College of Medicine , Seoul , Republic of Korea.,c Institute of Endemic Disease, Seoul National University Medical Research Center and Bundang Hospital , Seoul , Republic of Korea
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20
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Common features of F-18 FDG PET/CT findings in Scrub Typhus: prospective study before and after antibiotics therapy. Sci Rep 2019; 9:15397. [PMID: 31659261 PMCID: PMC6817906 DOI: 10.1038/s41598-019-51964-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 10/10/2019] [Indexed: 11/09/2022] Open
Abstract
Scrub typhus is an acute febrile illness caused by obligate intracellular organism Orientia tsutsugamushi. While there have been many reports on the evaluation of disease activity and infectious diseases using F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), the clinical value of FDG PET/CT in scrub typhus has not been fully investigated. We enrolled 17 patients who were 18 years of age or older and clinically suspected of having scrub typhus with eschar. Clinical assessments, blood samples, and FDG PET/CT images were obtained at enrolment and again after 3 weeks. The median age of the patients was 65 years; 9 (52.9%) patients were male. On initial FDG PET/CT, the eschars showed markedly increased FDG uptake on PET imaging that improved after treatment. Generalized lymphadenopathy and splenomegaly with high FDG uptake were observed in all patients. On follow-up FDG PET/CT after appropriate therapy, FDG uptake and sizes of eschar, lymph nodes, and spleen were markedly decreased. As far as we are aware, this is the first investigation with multiple patients of FDG PET/CT in scrub typhus and the demonstration of clinical utility. FDG PET/CT imaging of scrub typhus could provide useful information about the clinical features before and after antibiotic treatment.
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21
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Yue C, Li J, Jin H, Hua K, Zhou W, Wang Y, Cheng G, Liu D, Xu L, Chen Y, Zeng Y. Autophagy Is a Defense Mechanism Inhibiting Invasion and Inflammation During High-Virulent Haemophilus parasuis Infection in PK-15 Cells. Front Cell Infect Microbiol 2019; 9:93. [PMID: 31106159 PMCID: PMC6499186 DOI: 10.3389/fcimb.2019.00093] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 03/15/2019] [Indexed: 12/15/2022] Open
Abstract
Bacterial infections activate autophagy and autophagy restricts pathogens such as Haemophilus parasuis through specific mechanisms. Autophagy is associated with the pathogenesis of H. parasuis. However, the mechanisms have not been clarified. Here, we monitored autophagy processes using confocal microscopy, western blot, and transmission electron microscopy (TEM) and found that H. parasuis SH0165 (high-virulent strain) but not HN0001 (non-virulent strain) infection enhanced autophagy flux. The AMPK/mTOR autophagy pathway was required for autophagy initiation and ATG5, Beclin-1, ATG7, and ATG16L1 emerged as important components in the generation of the autophagosome during H. parasuis infection. Moreover, autophagy induced by H. parasuis SH0165 turned to fight against invaded bacteria and inhibit inflammation. Then we further demonstrated that autophagy blocked the production of the cytokines IL-8, CCL4, and CCL5 induced by SH0165 infection through the inhibition of NF-κB, p38, and JNK MAPK signaling pathway. Therefore, our findings suggest that autophagy may act as a cellular defense mechanism in response to H. parasuis and provide a new way that autophagy protects the host against H. parasuis infection.
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Affiliation(s)
- Chaoxiong Yue
- Brain and Cognition Research Institute, Wuhan University of Science and Technology, Wuhan, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Jinquan Li
- Brain and Cognition Research Institute, Wuhan University of Science and Technology, Wuhan, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Hui Jin
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Kexin Hua
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Wei Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yueyi Wang
- Brain and Cognition Research Institute, Wuhan University of Science and Technology, Wuhan, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Guirong Cheng
- Brain and Cognition Research Institute, Wuhan University of Science and Technology, Wuhan, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Dan Liu
- Brain and Cognition Research Institute, Wuhan University of Science and Technology, Wuhan, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Lang Xu
- Brain and Cognition Research Institute, Wuhan University of Science and Technology, Wuhan, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Yushan Chen
- Brain and Cognition Research Institute, Wuhan University of Science and Technology, Wuhan, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China.,Big Data Science and Engineering Research Institute, Wuhan University of Science and Technology, Wuhan, China
| | - Yan Zeng
- Brain and Cognition Research Institute, Wuhan University of Science and Technology, Wuhan, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China.,Big Data Science and Engineering Research Institute, Wuhan University of Science and Technology, Wuhan, China
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22
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Soong L. Dysregulated Th1 Immune and Vascular Responses in Scrub Typhus Pathogenesis. THE JOURNAL OF IMMUNOLOGY 2019; 200:1233-1240. [PMID: 29431689 DOI: 10.4049/jimmunol.1701219] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 11/30/2017] [Indexed: 12/25/2022]
Abstract
Scrub typhus is an emerging, insect-transmitted disease caused by Orientia tsutsugamushi, a Gram- and LPS-negative bacterium that replicates freely within professional phagocytes and endothelial cells. Scrub typhus is prevalent with high mortality rates, but information regarding its molecular pathogenesis, microbial virulence determinants, and key immune responses is limited. Improved animal models have recently been developed that respectively resemble the pathological features of self-limiting or severe scrub typhus in humans. Strong activation of Th1 and CD8, but not Th2 and regulatory T, immune responses, accompanied by altered angiopoietin/Tie2-related regulation, are hallmarks of lethal infection in murine models. This review, based primarily on recent advances from clinical and experimental studies, highlights tissue- and endothelial cell-specific biomarkers that are indicative of immune dysregulation. The potential roles of neutrophils and damage-associated molecular pattern molecules at late stages of disease are discussed in the context of vascular leakage, pulmonary and renal injury, and scrub typhus pathogenesis.
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Affiliation(s)
- Lynn Soong
- Department of Microbiology and Immunology, Center for Tropical Diseases, Center for Biodefense and Emerging Infectious Diseases, Sealy Center for Vaccine Development, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555; and .,Department of Pathology, Center for Tropical Diseases, Center for Biodefense and Emerging Infectious Diseases, Sealy Center for Vaccine Development, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555
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23
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Han YH, Hwang JH, Lee CS. Dissemination of Orientia tsutsugamushi in a Case of Scrub Typhus. Am J Trop Med Hyg 2019; 100:235-236. [PMID: 30795827 PMCID: PMC6367607 DOI: 10.4269/ajtmh.18-0689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Yeon-Hee Han
- Cyclotron Research Center, Molecular Imaging and Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea.,Department of Nuclear Medicine, Chonbuk National University Medical School, Jeonju, Republic of Korea
| | - Joo-Hee Hwang
- Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.,Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Republic of Korea
| | - Chang-Seop Lee
- Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Republic of Korea.,Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea
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Atg5 Supports Rickettsia australis Infection in Macrophages In Vitro and In Vivo. Infect Immun 2018; 87:IAI.00651-18. [PMID: 30297526 PMCID: PMC6300621 DOI: 10.1128/iai.00651-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 09/28/2018] [Indexed: 01/26/2023] Open
Abstract
Rickettsiae can cause life-threatening infections in humans. Macrophages are one of the initial targets for rickettsiae after inoculation by ticks. However, it remains poorly understood how rickettsiae remain free in macrophages prior to establishing their infection in microvascular endothelial cells. Here, we demonstrated that the concentration of Rickettsia australis was significantly greater in infected tissues of Atg5flox/flox mice than in the counterparts of Atg5flox/flox Lyz-Cre mice, in association with a reduced level of interleukin-1β (IL-1β) in serum. The greater concentration of R. australis in Atg5flox/flox bone marrow-derived macrophages (BMMs) than in Atg5flox/flox Lyz-Cre BMMs in vitro was abolished by exogenous treatment with recombinant IL-1β. Rickettsia australis induced significantly increased levels of light chain 3 (LC3) form II (LC3-II) and LC3 puncta in Atg5-competent BMMs but not in Atg5-deficient BMMs, while no p62 turnover was observed. Further analysis found the colocalization of LC3 with a small portion of R. australis and Rickettsia-containing double-membrane-bound vacuoles in the BMMs of B6 mice. Moreover, treatment with rapamycin significantly increased the concentrations of R. australis in B6 BMMs compared to those in the untreated B6 BMM controls. Taken together, our results demonstrate that Atg5 favors R. australis infection in mouse macrophages in association with a suppressed level of IL-1β production but not active autophagy flux. These data highlight the contribution of Atg5 in macrophages to the pathogenesis of rickettsial diseases.
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Ultrastructural visualization of Orientia tsutsugamushi in biopsied eschars and monocytes from scrub typhus patients in South Korea. Sci Rep 2018; 8:17373. [PMID: 30478364 PMCID: PMC6255831 DOI: 10.1038/s41598-018-35775-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 11/09/2018] [Indexed: 12/03/2022] Open
Abstract
Scrub typhus, which is caused by Orientia tsutsugamushi, is a public health problem in the Asian-Pacific region and is the third most frequently reported infectious disease in South Korea. While ultrastructural studies have been performed on O. tsutsugamushi in murine fibroblasts, its variable locations in patients have hampered similar studies in humans. Two patients with scrub typhus agreed to provide an eschar biopsy and peripheral blood, respectively. Transmission electron microscopy was performed separately on the necrotic crust and perifocal skin of the eschar, the peripheral blood, and the infected murine L cells. O. tsutsugamushi was located within or adjacent to the outermost layer of the perifocal inflamed skin of the eschar but not in the necrotic centre. O. tsutsugamushi in peripheral blood monocytes exhibited the characteristic features of O. tsutsugamushi in L cells, namely, nearly round shaped bacteria with a size of 1–2 µm and a double membrane bearing a clear halo-like outer layer. The findings confirmed that the bacterium was predominantly located in the inflamed skin around the eschar and that the bacterium had the same ultrastructural features in human monocytes as in L cells. These findings suggest that the perifocal area, not the necrotic centre, should be sampled for diagnosis.
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26
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Min CK, Kim HI, Ha NY, Kim Y, Kwon EK, Yen NTH, Youn JI, Jeon YK, Inn KS, Choi MS, Cho NH. A Type I Interferon and IL-10 Induced by Orientia tsutsugamushi Infection Suppresses Antigen-Specific T Cells and Their Memory Responses. Front Immunol 2018; 9:2022. [PMID: 30233599 PMCID: PMC6131522 DOI: 10.3389/fimmu.2018.02022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/16/2018] [Indexed: 12/31/2022] Open
Abstract
Despite the various roles of type I interferon (type I IFN) responses during bacterial infection, its specific effects in vivo have been poorly characterized in scrub typhus caused by Orientia tsutsugamushi infection. Here, we show that type I IFNs are primarily induced via intracellular nucleic acids sensors, including RIG-I/MAVS and cGAS/STING pathways, during O. tsutsugamushi invasion. However, type I IFN signaling did not significantly affect pathogenesis, mortality, or bacterial burden during primary infection in vivo, when assessed in a mice model lacking a receptor for type I IFNs (IFNAR KO). Rather, it significantly impaired the induction of antigen-specific T cells and reduced memory T cell responses. IFNAR KO mice that recovered from primary infection showed stronger antigen-specific T cell responses, especially Th1, and more efficiently controlled bacteremia during secondary infection than wild type mice. Enhanced IL-10 expression by macrophages in the presence of type I IFN signaling might play a significant role in the suppression of antigen-specific T cell responses as neutralization or knock-out (KO) of IL-10 increased T cell responses in vitro. Therefore, induction of the type I IFN/IL-10 axis by O. tsutsugamushi infection might play a significant role in the suppression of T cell responses and contribute to the short longevity of cell-mediated immunity, often observed in scrub typhus patients.
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Affiliation(s)
- Chan-Ki Min
- Department of Microbiology and Immunology,Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences,Seoul National University College of Medicine, Seoul, South Korea
| | - Hong-Ii Kim
- Department of Microbiology and Immunology,Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences,Seoul National University College of Medicine, Seoul, South Korea
| | - Na-Young Ha
- Department of Microbiology and Immunology,Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences,Seoul National University College of Medicine, Seoul, South Korea
| | - Yuri Kim
- Department of Microbiology and Immunology,Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences,Seoul National University College of Medicine, Seoul, South Korea
| | - Eun-Kyung Kwon
- Department of Microbiology and Immunology,Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences,Seoul National University College of Medicine, Seoul, South Korea
| | - Nguyen Thi Hai Yen
- Department of Microbiology and Immunology,Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences,Seoul National University College of Medicine, Seoul, South Korea
| | - Je-In Youn
- Department of Biomedical Sciences,Seoul National University College of Medicine, Seoul, South Korea.,Wide River Institute of Immunology, Seoul National University College of Medicine, Gangwon-do, South Korea
| | - Yoon Kyung Jeon
- Department of Pathology, Seoul National University College of Medicine, Seoul, South Korea
| | - Kyung-Soo Inn
- Department of Pharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul, South Korea
| | - Myung-Sik Choi
- Department of Microbiology and Immunology,Seoul National University College of Medicine, Seoul, South Korea
| | - Nam-Hyuk Cho
- Department of Microbiology and Immunology,Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences,Seoul National University College of Medicine, Seoul, South Korea.,Wide River Institute of Immunology, Seoul National University College of Medicine, Gangwon-do, South Korea.,Institute of Endemic Disease, Seoul National University Medical Research Center and Bundang Hospital, Seoul, South Korea
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27
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Parker A, Lawson MAE, Vaux L, Pin C. Host-microbe interaction in the gastrointestinal tract. Environ Microbiol 2018; 20:2337-2353. [PMID: 28892253 PMCID: PMC6175405 DOI: 10.1111/1462-2920.13926] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Revised: 08/25/2017] [Accepted: 08/31/2017] [Indexed: 12/13/2022]
Abstract
The gastrointestinal tract is a highly complex organ in which multiple dynamic physiological processes are tightly coordinated while interacting with a dense and extremely diverse microbial population. From establishment in early life, through to host-microbe symbiosis in adulthood, the gut microbiota plays a vital role in our development and health. The effect of the microbiota on gut development and physiology is highlighted by anatomical and functional changes in germ-free mice, affecting the gut epithelium, immune system and enteric nervous system. Microbial colonisation promotes competent innate and acquired mucosal immune systems, epithelial renewal, barrier integrity, and mucosal vascularisation and innervation. Interacting or shared signalling pathways across different physiological systems of the gut could explain how all these changes are coordinated during postnatal colonisation, or after the introduction of microbiota into germ-free models. The application of cell-based in-vitro experimental systems and mathematical modelling can shed light on the molecular and signalling pathways which regulate the development and maintenance of homeostasis in the gut and beyond.
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Affiliation(s)
- Aimée Parker
- Quadram Institute BioscienceNorwich Research ParkNR4 7UAUK
| | | | - Laura Vaux
- Quadram Institute BioscienceNorwich Research ParkNR4 7UAUK
| | - Carmen Pin
- Quadram Institute BioscienceNorwich Research ParkNR4 7UAUK
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28
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Díaz FE, Abarca K, Kalergis AM. An Update on Host-Pathogen Interplay and Modulation of Immune Responses during Orientia tsutsugamushi Infection. Clin Microbiol Rev 2018; 31:e00076-17. [PMID: 29386235 PMCID: PMC5967693 DOI: 10.1128/cmr.00076-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The obligate intracellular bacterium Orientia tsutsugamushi is the causative agent of scrub typhus in humans, a serious mite-borne disease present in a widespread area of endemicity, which affects an estimated 1 million people every year. This disease may exhibit a broad range of presentations, ranging from asymptomatic to fatal conditions, with the latter being due to disseminated endothelial infection and organ injury. Unique characteristics of the biology and host-pathogen interactions of O. tsutsugamushi, including the high antigenic diversity among strains and the highly variable, short-lived memory responses developed by the host, underlie difficulties faced in the pursuit of an effective vaccine, which is an imperative need. Other factors that have hindered scientific progress relative to the infectious mechanisms of and the immune response triggered by this bacterium in vertebrate hosts include the limited number of mechanistic studies performed on animal models and the lack of genetic tools currently available for this pathogen. However, recent advances in animal model development are promising to improve our understanding of host-pathogen interactions. Here, we comprehensively discuss the recent advances in and future perspectives on host-pathogen interactions and the modulation of immune responses related to this reemerging disease, highlighting the role of animal models.
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Affiliation(s)
- Fabián E Díaz
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Katia Abarca
- Departamento en Enfermedades Infecciosas e Inmunología Pediátricas, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alexis M Kalergis
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
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29
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Luce-Fedrow A, Lehman ML, Kelly DJ, Mullins K, Maina AN, Stewart RL, Ge H, John HS, Jiang J, Richards AL. A Review of Scrub Typhus (Orientia tsutsugamushi and Related Organisms): Then, Now, and Tomorrow. Trop Med Infect Dis 2018; 3:E8. [PMID: 30274407 PMCID: PMC6136631 DOI: 10.3390/tropicalmed3010008] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 12/26/2022] Open
Abstract
Scrub typhus and the rickettsial diseases represent some of the oldest recognized vector-transmitted diseases, fraught with a rich historical aspect, particularly as applied to military/wartime situations. The vectors of Orientia tsutsugamushi were once thought to be confined to an area designated as the Tsutsugamushi Triangle. However, recent reports of scrub typhus caused by Orientia species other than O. tsutsugamushi well beyond the limits of the Tsutsugamushi Triangle have triggered concerns about the worldwide presence of scrub typhus. It is not known whether the vectors of O. tsutsugamushi will be the same for the new Orientia species, and this should be a consideration during outbreak/surveillance investigations. Additionally, concerns surrounding the antibiotic resistance of O. tsutsugamushi have led to considerations for the amendment of treatment protocols, and the need for enhanced public health awareness in both the civilian and medical professional communities. In this review, we discuss the history, outbreaks, antibiotic resistance, and burgeoning genomic advances associated with one of the world's oldest recognized vector-borne pathogens, O. tsutsugamushi.
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Affiliation(s)
- Alison Luce-Fedrow
- Department of Biology, Shippensburg University, Shippensburg, PA 17202, USA.
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
| | - Marcie L Lehman
- Department of Biology, Shippensburg University, Shippensburg, PA 17202, USA.
| | - Daryl J Kelly
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210, USA.
| | - Kristin Mullins
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
| | - Alice N Maina
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
| | - Richard L Stewart
- Department of Biology, Shippensburg University, Shippensburg, PA 17202, USA.
| | - Hong Ge
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
| | - Heidi St John
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
| | - Ju Jiang
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
| | - Allen L Richards
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
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30
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Otten C, Brilli M, Vollmer W, Viollier PH, Salje J. Peptidoglycan in obligate intracellular bacteria. Mol Microbiol 2018; 107:142-163. [PMID: 29178391 PMCID: PMC5814848 DOI: 10.1111/mmi.13880] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2017] [Indexed: 01/08/2023]
Abstract
Peptidoglycan is the predominant stress-bearing structure in the cell envelope of most bacteria, and also a potent stimulator of the eukaryotic immune system. Obligate intracellular bacteria replicate exclusively within the interior of living cells, an osmotically protected niche. Under these conditions peptidoglycan is not necessarily needed to maintain the integrity of the bacterial cell. Moreover, the presence of peptidoglycan puts bacteria at risk of detection and destruction by host peptidoglycan recognition factors and downstream effectors. This has resulted in a selective pressure and opportunity to reduce the levels of peptidoglycan. In this review we have analysed the occurrence of genes involved in peptidoglycan metabolism across the major obligate intracellular bacterial species. From this comparative analysis, we have identified a group of predicted 'peptidoglycan-intermediate' organisms that includes the Chlamydiae, Orientia tsutsugamushi, Wolbachia and Anaplasma marginale. This grouping is likely to reflect biological differences in their infection cycle compared with peptidoglycan-negative obligate intracellular bacteria such as Ehrlichia and Anaplasma phagocytophilum, as well as obligate intracellular bacteria with classical peptidoglycan such as Coxiella, Buchnera and members of the Rickettsia genus. The signature gene set of the peptidoglycan-intermediate group reveals insights into minimal enzymatic requirements for building a peptidoglycan-like sacculus and/or division septum.
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Affiliation(s)
- Christian Otten
- The Centre for Bacterial Cell BiologyInstitute for Cell and Molecular Biosciences, Newcastle UniversityNewcastle upon TyneNE2 4AXUK
| | - Matteo Brilli
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE)University of Padova. Agripolis ‐ V.le dell'Università, 16 | 35020 Legnaro PadovaItaly
- Present address:
Department of BiosciencesUniversity of Milan, via Celoria 26(MI)Italy
| | - Waldemar Vollmer
- The Centre for Bacterial Cell BiologyInstitute for Cell and Molecular Biosciences, Newcastle UniversityNewcastle upon TyneNE2 4AXUK
| | - Patrick H. Viollier
- Department of Microbiology and Molecular MedicineInstitute of Genetics & Genomics in Geneva (iGE3), University of GenevaGenevaSwitzerland
| | - Jeanne Salje
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global HealthUniversity of OxfordOxfordUK
- Mahidol‐Oxford Tropical Medicine Research UnitMahidol UniversityBangkokThailand
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31
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Orientia tsutsugamushi Modulates Endoplasmic Reticulum-Associated Degradation To Benefit Its Growth. Infect Immun 2017; 86:IAI.00596-17. [PMID: 29109174 DOI: 10.1128/iai.00596-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 10/26/2017] [Indexed: 01/11/2023] Open
Abstract
Orientia tsutsugamushi, an obligate intracellular bacterium that is auxotrophic for the aromatic amino acids and histidine, causes scrub typhus, a potentially deadly infection that threatens 1 billion people. O. tsutsugamushi growth is minimal during the first 24 to 48 h of infection but its growth becomes logarithmic thereafter. How the pathogen modulates cellular functions to support its growth is poorly understood. The unfolded protein response (UPR) is a cytoprotective pathway that relieves endoplasmic reticulum (ER) stress by promoting ER-associated degradation (ERAD) of misfolded proteins. Here, we show that O. tsutsugamushi invokes the UPR in the first 48 h and benefits from ER stress in an amino acid-dependent manner. O. tsutsugamushi also impedes ERAD during this time period. By 72 h, ER stress is alleviated and ERAD proceeds unhindered. Sustained inhibition of ERAD using RNA interference results in an O. tsutsugamushi growth defect at 72 h that can be rescued by amino acid supplementation. Thus, O. tsutsugamushi temporally stalls ERAD until ERAD-derived amino acids are needed to support its growth. The O. tsutsugamushi effector Ank4 is linked to this phenomenon. Ank4 interacts with Bat3, a eukaryotic chaperone that is essential for ERAD, and is transiently expressed by O. tsutsugamushi during the infection period when it inhibits ERAD. Ectopically expressed Ank4 blocks ERAD to phenocopy O. tsutsugamushi infection. Our data reveal a novel mechanism by which an obligate intracellular bacterial pathogen modulates ERAD to satisfy its nutritional virulence requirements.
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32
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Affiliation(s)
- Jeanne Salje
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- * E-mail:
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33
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Kimmey JM, Stallings CL. Bacterial Pathogens versus Autophagy: Implications for Therapeutic Interventions. Trends Mol Med 2016; 22:1060-1076. [PMID: 27866924 DOI: 10.1016/j.molmed.2016.10.008] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 10/18/2016] [Accepted: 10/18/2016] [Indexed: 12/19/2022]
Abstract
Research in recent years has focused significantly on the role of selective macroautophagy in targeting intracellular pathogens for lysosomal degradation, a process termed xenophagy. In this review we evaluate the proposed roles for xenophagy in controlling bacterial infection, highlighting the concept that successful pathogens have evolved ways to subvert or exploit this defense, minimizing the actual effectiveness of xenophagy in innate immunity. Instead, studies in animal models have revealed that autophagy-associated proteins often function outside of xenophagy to influence bacterial pathogenesis. In light of current efforts to manipulate autophagy and the development of host-directed therapies to fight bacterial infections, we also discuss the implications stemming from the complicated relationship that exists between autophagy and bacterial pathogens.
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Affiliation(s)
- Jacqueline M Kimmey
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Christina L Stallings
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA.
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34
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Abstract
The obligate intracellular bacterium Orientia tsutsugamushi is responsible for more than one million cases of scrub typhus annually throughout the Asia-Pacific region. Human infection occurs via the bite of the larval form (chigger) of several species of trombiculid mites. While in some patients the result of infection is a mild, febrile illness, others experience severe complications, which may even be fatal. This review discusses the genome and biology of the causative agent, the changing epidemiology of scrub typhus, the challenges of its diagnosis, and current treatment recommendations.
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Affiliation(s)
- Sunil Thomas
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania USA
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35
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Loi M, Müller A, Steinbach K, Niven J, Barreira da Silva R, Paul P, Ligeon LA, Caruso A, Albrecht RA, Becker AC, Annaheim N, Nowag H, Dengjel J, García-Sastre A, Merkler D, Münz C, Gannagé M. Macroautophagy Proteins Control MHC Class I Levels on Dendritic Cells and Shape Anti-viral CD8(+) T Cell Responses. Cell Rep 2016; 15:1076-1087. [PMID: 27117419 DOI: 10.1016/j.celrep.2016.04.002] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/10/2016] [Accepted: 03/27/2016] [Indexed: 01/08/2023] Open
Abstract
The macroautophagy machinery has been implicated in MHC class II restricted antigen presentation. Here, we report that this machinery assists in the internalization of MHC class I molecules. In the absence of the autophagy factors Atg5 and Atg7, MHC class I surface levels are elevated due to decreased endocytosis and degradation. Internalization of MHC class I molecules occurs less efficiently if AAK1 cannot be recruited via Atg8/LC3B. In the absence of Atg-dependent MHC class I internalization, dendritic cells stimulate CD8(+) T cell responses more efficiently in vitro and in vivo. During viral infections, lack of Atg5 results in enhanced influenza- and LCMV-specific CD8(+) T cell responses in vivo. Elevated influenza-specific CD8(+) T cell responses are associated with better immune control of this infection. Thus, the macroautophagy machinery orchestrates T cell immunity by supporting MHC class II but compromises MHC class I restricted antigen presentation.
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Affiliation(s)
- Monica Loi
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland
| | - Anne Müller
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland
| | - Karin Steinbach
- Department of Pathology and Immunology, School of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Jennifer Niven
- Department of Pathology and Immunology, School of Medicine, University of Geneva, 1211 Geneva, Switzerland; Division of Rheumatology, Department of Internal Medicine, University Hospital, Geneva 1205, Switzerland
| | - Rosa Barreira da Silva
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland
| | - Petra Paul
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland
| | - Laure-Anne Ligeon
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland
| | - Assunta Caruso
- Department of Pathology and Immunology, School of Medicine, University of Geneva, 1211 Geneva, Switzerland; Division of Rheumatology, Department of Internal Medicine, University Hospital, Geneva 1205, Switzerland
| | - Randy A Albrecht
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Andrea C Becker
- Department of Dermatology, Medical Center; ZBSA Center for Biological Systems Analysis; BIOSS Centre for Biological Signalling Studies; and FRIAS Freiburg Institute for Advanced Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Nicolas Annaheim
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland
| | - Heike Nowag
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland
| | - Jörn Dengjel
- Department of Dermatology, Medical Center; ZBSA Center for Biological Systems Analysis; BIOSS Centre for Biological Signalling Studies; and FRIAS Freiburg Institute for Advanced Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Adolfo García-Sastre
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Doron Merkler
- Department of Pathology and Immunology, School of Medicine, University of Geneva, 1211 Geneva, Switzerland; Department of Neuropathology, University Medical Center, 37099 Göttingen, Germany
| | - Christian Münz
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland.
| | - Monique Gannagé
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland; Department of Pathology and Immunology, School of Medicine, University of Geneva, 1211 Geneva, Switzerland; Division of Rheumatology, Department of Internal Medicine, University Hospital, Geneva 1205, Switzerland.
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36
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Luce-Fedrow A, Mullins K, Kostik AP, St John HK, Jiang J, Richards AL. Strategies for detecting rickettsiae and diagnosing rickettsial diseases. Future Microbiol 2016; 10:537-64. [PMID: 25865193 DOI: 10.2217/fmb.14.141] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Rickettsial diseases and scrub typhus constitute a group of the oldest known vector-borne diseases. The cosmopolitan distribution of the vectors that transmit rickettsiae and orientiae leads to a worldwide prevalence of these diseases. Despite their significant historical status, detection and diagnosis of these diseases are still evolving today. Serological methods remain among the most prevalent techniques used for the detection/diagnosis of rickettsial diseases and scrub typhus. Molecular techniques have been instrumental in increasing the sensitivity/specificity of diagnosis, identifying new Rickettsia and Orientia species and have enhanced epidemiological capabilities when used in combination with serological methods. In this review, we discuss these techniques and their associated pros and cons.
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Affiliation(s)
- Alison Luce-Fedrow
- Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
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37
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Steele S, Brunton J, Kawula T. The role of autophagy in intracellular pathogen nutrient acquisition. Front Cell Infect Microbiol 2015; 5:51. [PMID: 26106587 PMCID: PMC4460576 DOI: 10.3389/fcimb.2015.00051] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 05/26/2015] [Indexed: 01/01/2023] Open
Abstract
Following entry into host cells intracellular pathogens must simultaneously evade innate host defense mechanisms and acquire energy and anabolic substrates from the nutrient-limited intracellular environment. Most of the potential intracellular nutrient sources are stored within complex macromolecules that are not immediately accessible by intracellular pathogens. To obtain nutrients for proliferation, intracellular pathogens must compete with the host cell for newly-imported simple nutrients or degrade host nutrient storage structures into their constituent components (fatty acids, carbohydrates, and amino acids). It is becoming increasingly evident that intracellular pathogens have evolved a wide variety of strategies to accomplish this task. One recurrent microbial strategy is to exploit host degradative processes that break down host macromolecules into simple nutrients that the microbe can use. Herein we focus on how a subset of bacterial, viral, and eukaryotic pathogens leverage the host process of autophagy to acquire nutrients that support their growth within infected cells.
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Affiliation(s)
- Shaun Steele
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina Chapel Hill, NC, USA
| | - Jason Brunton
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina Chapel Hill, NC, USA
| | - Thomas Kawula
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina Chapel Hill, NC, USA
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Rescigno M. Dendritic cell functions: Learning from microbial evasion strategies. Semin Immunol 2015; 27:119-24. [PMID: 25843245 DOI: 10.1016/j.smim.2015.03.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 03/17/2015] [Indexed: 01/16/2023]
Abstract
Dendritic cells (DCs) are specialized antigen presenting cells (APC) that are fundamental to initiate both immunity and tolerance. DCs play a 'sentinel' role to protect our body from potential pathogens and induce tolerogenic responses toward harmless antigens. The flexibility of DCs or macrophages to adapt to the environment and to respond accordingly can be hijacked by pathogens for their own interest to transform a potentially immunogenic APC into a tolerogenic cell with clear consequences in pathogen clearance. While these immune evasion mechanisms can be detrimental for the host, they can highlight important molecular pathways in DCs necessary for their function. In this review we will mention several mechanisms employed by pathogens to evade DC patrolling function.
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Affiliation(s)
- Maria Rescigno
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy; Department of Health Sciences, School of Medicine, University of Milan, Milan, Italy.
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Cheong TC, Shin EP, Kwon EK, Choi JH, Wang KK, Sharma P, Choi KH, Lim JM, Kim HG, Oh K, Jeon JH, So I, Kim IG, Choi MS, Kim YK, Seong SY, Kim YR, Cho NH. Functional manipulation of dendritic cells by photoswitchable generation of intracellular reactive oxygen species. ACS Chem Biol 2015; 10:757-65. [PMID: 25458073 DOI: 10.1021/cb5009124] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reactive oxygen species (ROS) play an important role in cellular signaling as second messengers. However, studying the role of ROS in physiological redox signaling has been hampered by technical difficulties in controlling their generation within cells. Here, we utilize two inert components, a photosensitizer and light, to finely manipulate the generation of intracellular ROS and examine their specific role in activating dendritic cells (DCs). Photoswitchable generation of intracellular ROS rapidly induced cytosolic mobilization of Ca(2+), differential activation of mitogen-activated protein kinases, and nuclear translocation of NF-κB. Moreover, a transient intracellular ROS surge could activate immature DCs to mature and potently enhance migration in vitro and in vivo. Finally, we observed that intracellular ROS-stimulated DCs enhanced antigen specific T-cell responses in vitro and in vivo, which led to delayed tumor growth and prolonged survival of tumor-bearing mice when immunized with a specific tumor antigen. Therefore, a transient intracellular ROS surge alone, if properly manipulated, can cause immature DCs to differentiate into a motile state and mature forms that are sufficient to initiate adaptive T cell responses in vivo.
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Affiliation(s)
| | - Eon Pil Shin
- Department
of Chemistry, Yonsei University, Seoul, Republic of Korea
| | | | | | - Kang-Kyun Wang
- Department
of Chemistry, Yonsei University, Seoul, Republic of Korea
| | | | - Kyong Hoon Choi
- Department
of Chemistry, Yonsei University, Seoul, Republic of Korea
| | - Jin-Muk Lim
- Biomedical
Knowledge Engineering Laboratory, Dental Research Institute and Institute
of Human-Environment Interface Biology, Seoul National University, Seoul, Republic of Korea
| | - Hong-Gee Kim
- Biomedical
Knowledge Engineering Laboratory, Dental Research Institute and Institute
of Human-Environment Interface Biology, Seoul National University, Seoul, Republic of Korea
| | | | | | | | | | | | - Young Keun Kim
- Department
of Materials Science and Engineering, Korea University, Seoul, Republic of Korea
| | | | - Yong-Rok Kim
- Department
of Chemistry, Yonsei University, Seoul, Republic of Korea
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40
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Ha NY, Sharma P, Kim G, Kim Y, Min CK, Choi MS, Kim IS, Cho NH. Immunization with an autotransporter protein of Orientia tsutsugamushi provides protective immunity against scrub typhus. PLoS Negl Trop Dis 2015; 9:e0003585. [PMID: 25768004 PMCID: PMC4359152 DOI: 10.1371/journal.pntd.0003585] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 02/03/2015] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Scrub typhus is an acute febrile disease caused by Orientia tsutsugamushi infection. Recently, the rapid increase of scrub typhus incidence in several countries within the endemic region has become a serious public health issue. Despite the wide range of preventative approaches that have been attempted in the past 70 years, all have failed to develop an effective prophylactic vaccine. Currently, the selection of the proper antigens is one of the critical barriers to generating cross-protective immunity against antigenically-variable strains of O. tsutsugamushi. METHODOLOGY/PRINCIPAL FINDINGS We examined the potential role of ScaA protein, an autotransporter protein of O. tsutsugamushi, in bacterial pathogenesis and evaluated the protective attributes of ScaA immunization in lethal O. tsutsugamushi infection in mice. Our findings demonstrate that ScaA functions as a bacterial adhesion factor, and anti-ScaA antibody significantly neutralizes bacterial infection of host cells. In addition, immunization with ScaA not only provides protective immunity against lethal challenges with the homologous strain, but also confers significant protection against heterologous strains when combined with TSA56, a major outer membrane protein of O. tsutsugamushi. CONCLUSIONS/SIGNIFICANCE Immunization of ScaA proteins provides protective immunity in mice when challenged with the homologous strain and significantly enhanced protective immunity against infection with heterologous strains. To our knowledge, this is the most promising result of scrub typhus vaccination trials against infection of heterologous strains in mouse models thus far.
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Affiliation(s)
- Na-Young Ha
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Prashant Sharma
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Gwanghun Kim
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Yuri Kim
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Chan-Ki Min
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Myung-Sik Choi
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Ik-Sang Kim
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Nam-Hyuk Cho
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
- Institute of Endemic Disease, Seoul National University Medical Research Center and Bundang Hospital, Seoul, Republic of Korea
- * E-mail:
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41
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Soong L, Wang H, Shelite TR, Liang Y, Mendell NL, Sun J, Gong B, Valbuena GA, Bouyer DH, Walker DH. Strong type 1, but impaired type 2, immune responses contribute to Orientia tsutsugamushi-induced pathology in mice. PLoS Negl Trop Dis 2014; 8:e3191. [PMID: 25254971 PMCID: PMC4177881 DOI: 10.1371/journal.pntd.0003191] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 08/14/2014] [Indexed: 12/22/2022] Open
Abstract
Scrub typhus is a neglected, but important, tropical disease, which puts one-third of the world's population at risk. The disease is caused by Orientia tsutsugamushi, an obligately intracellular Gram-negative bacterium. Dysregulation in immune responses is known to contribute to disease pathogenesis; however, the nature and molecular basis of immune alterations are poorly defined. This study made use of a newly developed murine model of severe scrub typhus and focused on innate regulators and vascular growth factors in O. tsutsugamushi-infected liver, lungs and spleen. We found no activation or even reduction in base-line expression for multiple molecules (IL-7, IL-4, IL-13, GATA3, ROR-γt, and CXCL12) at 2, 6 and 10 days post-infection. This selective impairment in type 2-related immune responses correlated with a significant activation of the genes for IL-1β, IL-6, IL-10, TNF-α, IFN-γ, as well as CXCR3- and CXCR1-related chemokines in inflamed tissues. The elevated angiopoietin (Ang)-2 expression and Ang-2/Ang-1 ratios suggested excessive inflammation and the loss of endothelial integrity. These alterations, together with extensive recruitment of myeloperoxidase (MPO)-expressing neutrophils and the influx of CD3+ T cells, contributed to acute tissue damage and animal death. This is the first report of selective alterations in a panel of immune regulators during early O. tsutsugamushi infection in intravenously inoculated C57BL/6 mice. Our findings shed new light on the pathogenic mechanisms associated with severe scrub typhus and suggest potential targets for therapeutic investigation.
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Affiliation(s)
- Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, Center for Tropical Diseases, Sealy Center for Vaccine Development, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail:
| | - Hui Wang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Thomas R. Shelite
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, Center for Tropical Diseases, Sealy Center for Vaccine Development, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Yuejin Liang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Nicole L. Mendell
- Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, Center for Tropical Diseases, Sealy Center for Vaccine Development, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Bin Gong
- Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, Center for Tropical Diseases, Sealy Center for Vaccine Development, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Gustavo A. Valbuena
- Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, Center for Tropical Diseases, Sealy Center for Vaccine Development, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Donald H. Bouyer
- Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, Center for Tropical Diseases, Sealy Center for Vaccine Development, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - David H. Walker
- Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, Center for Tropical Diseases, Sealy Center for Vaccine Development, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
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Gorvel L, Textoris J, Banchereau R, Ben Amara A, Tantibhedhyangkul W, von Bargen K, Ka MB, Capo C, Ghigo E, Gorvel JP, Mege JL. Intracellular bacteria interfere with dendritic cell functions: role of the type I interferon pathway. PLoS One 2014; 9:e99420. [PMID: 24915541 PMCID: PMC4051653 DOI: 10.1371/journal.pone.0099420] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 05/14/2014] [Indexed: 01/18/2023] Open
Abstract
Dendritic cells (DCs) orchestrate host defenses against microorganisms. In infectious diseases due to intracellular bacteria, the inefficiency of the immune system to eradicate microorganisms has been attributed to the hijacking of DC functions. In this study, we selected intracellular bacterial pathogens with distinct lifestyles and explored the responses of monocyte-derived DCs (moDCs). Using lipopolysaccharide as a control, we found that Orientia tsutsugamushi, the causative agent of scrub typhus that survives in the cytosol of target cells, induced moDC maturation, as assessed by decreased endocytosis activity, the ability to induce lymphocyte proliferation and the membrane expression of phenotypic markers. In contrast, Coxiella burnetii, the agent of Q fever, and Brucella abortus, the agent of brucellosis, both of which reside in vacuolar compartments, only partly induced the maturation of moDCs, as demonstrated by a phenotypic analysis. To analyze the mechanisms used by C. burnetii and B. abortus to alter moDC activation, we performed microarray and found that C. burnetii and B. abortus induced a specific signature consisting of TLR4, TLR3, STAT1 and interferon response genes. These genes were down-modulated in response to C. burnetii and B. abortus but up-modulated in moDCs activated by lipopolysaccharide and O. tsutsugamushi. This transcriptional alteration was associated with the defective interferon-β production. This study demonstrates that intracellular bacteria specifically affect moDC responses and emphasizes how C. burnetii and B. abortus interfere with moDC activation and the antimicrobial immune response. We believe that comparing infection by several bacterial species may be useful for defining new pathways and biomarkers and for developing new treatment strategies.
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Affiliation(s)
- Laurent Gorvel
- Centre National de la Recherche Scientifique UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, Marseille, France
| | - Julien Textoris
- Centre National de la Recherche Scientifique UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, Marseille, France
| | - Romain Banchereau
- Baylor Institute for Immunology Research, Dallas, Texas, United States of America
| | - Amira Ben Amara
- Centre National de la Recherche Scientifique UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, Marseille, France
| | - Wiwit Tantibhedhyangkul
- Centre National de la Recherche Scientifique UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, Marseille, France
- Department of Immunology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Kristin von Bargen
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, INSERM, U1104, CNRS, UMR7280, Marseille, France
| | - Mignane B. Ka
- Centre National de la Recherche Scientifique UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, Marseille, France
| | - Christian Capo
- Centre National de la Recherche Scientifique UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, Marseille, France
| | - Eric Ghigo
- Centre National de la Recherche Scientifique UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, Marseille, France
| | - Jean-Pierre Gorvel
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, INSERM, U1104, CNRS, UMR7280, Marseille, France
| | - Jean-Louis Mege
- Centre National de la Recherche Scientifique UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, Marseille, France
- * E-mail:
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Astrup E, Ranheim T, Damås JK, Davì G, Santilli F, Jensenius M, Vitale G, Aukrust P, Olano JP, Otterdal K. Increased expression of the homeostatic chemokines CCL19 and CCL21 in clinical and experimental Rickettsia conorii infection. BMC Infect Dis 2014; 14:70. [PMID: 24507453 PMCID: PMC3923395 DOI: 10.1186/1471-2334-14-70] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 02/05/2014] [Indexed: 12/18/2022] Open
Abstract
Background Based on their essential role in concerting immunological and inflammatory responses we hypothesized that the homeostatic chemokines CCL19 and CCL21 may play a pathogenic role in rickettsiae infection. Methods Serum levels of CCL19 and CCL21 in patients with R. africae and R. conorii infection were analyzed by enzyme immunoassays. Lungs from R. conorii infected mice were examined for CCL19, CCL21 and CCR7 expression by immunohistochemistry. Results We found that patients with R. africae infection (n = 15) and in particular those with R. conorii infection (n = 16) had elevated serum levels of CCL19 on admission, with a decline during follow-up. While a similar pattern was seen for CCL21 in R. africae infection, patients with R. conorii infection showed persistently increased CCL21 levels during follow-up. In experimental R. conorii infection, we found strong immunostaining of CCL19 and CCL21 in the lungs, particularly in individuals that had received lethal doses. Immunofluorescence showed co-localization of CCR7 to endothelial cells, macrophages and fibroblasts within the lung tissue of R. conorii infected mice. Conclusions Our findings suggest that the CCL19/CCL21/CCR7 axis is up-regulated during R. africae and in particular during R. conorii infection, which may potentially contribute to the pathogenesis of these disorders.
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Affiliation(s)
- Elisabeth Astrup
- Institute of Clinical Medicine, Akershus University Hospital, Sykehusveien 25, Lørenskog 1478, Norway.
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Abstract
Autophagy is used by the cell to degrade various substrates; this is achieved either through the canonical, non-selective autophagy pathway or through selective autophagy. Both pathways proceed via distinct key steps and use specific molecular mechanisms. The canonical autophagy pathway has been studied in detail in mammalian cells and in model organisms, such as yeast. The molecular mechanisms underlying non-canonical autophagy, in addition to alternative pathways that are independent of some of the key autophagy machinery, are beginning to become clear. Besides degradation of cellular proteins, autophagy proteins are also involved in many other functions, some of which are important during bacterial infections. Autophagy functions as an antibacterial mechanism. The induction and recognition mechanisms for several bacterial species have been elucidated. Bacteria can escape killing by autophagy and some can even use autophagy to promote infection of host cells, through the interaction between bacterial effector proteins and autophagy components. The knowledge about bacteria–autophagy interactions will inform the design of new drugs and treatments against bacterial infections.
Autophagy not only degrades components of host cells but can also target intracellular bacteria and thus contribute to host defences. Here, Huang and Brumell discuss the canonical and selective pathways of antibacterial autophagy, as well as the ways in which bacteria can escape from them and sometimes even use them to promote infection. Autophagy is a cellular process that targets proteins, lipids and organelles to lysosomes for degradation, but it has also been shown to combat infection with various pathogenic bacteria. In turn, bacteria have developed diverse strategies to avoid autophagy by interfering with autophagy signalling or the autophagy machinery and, in some cases, they even exploit autophagy for their growth. In this Review, we discuss canonical and non-canonical autophagy pathways and our current knowledge of antibacterial autophagy, with a focus on the interplay between bacterial factors and autophagy components.
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Update March 2013. Lymphat Res Biol 2013. [DOI: 10.1089/lrb.2013.1113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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