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Petermann M, Orfanos Z, Sellau J, Gharaibeh M, Lotter H, Fleischer B, Keller C. CCR2 Deficiency Impairs Ly6C lo and Ly6C hi Monocyte Responses in Orientia tsutsugamushi Infection. Front Immunol 2021; 12:670219. [PMID: 34290699 PMCID: PMC8287586 DOI: 10.3389/fimmu.2021.670219] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 06/21/2021] [Indexed: 12/24/2022] Open
Abstract
Orientia (O.) tsutsugamushi, the causative agent of scrub typhus, is a neglected, obligate intracellular bacterium that has a prominent tropism for monocytes and macrophages. Complications often involve the lung, where interstitial pneumonia is a typical finding. The severity of scrub typhus in humans has been linked to altered plasma concentrations of chemokines which are known to act as chemoattractants for myeloid cells. The trafficking and function of monocyte responses is critically regulated by interaction of the CC chemokine ligand 2 (CCL2) and its CC chemokine receptor CCR2. In a self-healing mouse model of intradermal infection with the human-pathogenic Karp strain of O. tsutsugamushi, we investigated the role of CCR2 on bacterial dissemination, development of symptoms, lung histology and monocyte subsets in blood and lungs. CCR2-deficient mice showed a delayed onset of disease and resolution of symptoms, higher concentrations and impaired clearance of bacteria in the lung and the liver, accompanied by a slow infiltration of interstitial macrophages into the lungs. In the blood, we found an induction of circulating monocytes that depended on CCR2, while only a small increase in Ly6Chi monocytes was observed in CCR2-/- mice. In the lung, significantly higher numbers of Ly6Chi and Ly6Clo monocytes were found in the C57BL/6 mice compared to CCR2-/- mice. Both wildtype and CCR2-deficient mice developed an inflammatory milieu as shown by cytokine and inos/arg1 mRNA induction in the lung, but with delayed kinetics in CCR2-deficient mice. Histopathology revealed that infiltration of macrophages to the parenchyma, but not into the peribronchial tissue, depended on CCR2. In sum, our data suggest that in Orientia infection, CCR2 drives blood monocytosis and the influx and activation of Ly6Chi and Ly6Clo monocytes into the lung, thereby accelerating bacterial replication and development of interstitial pulmonary inflammation.
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Affiliation(s)
- Michael Petermann
- Department of Molecular Biology and Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Zacharias Orfanos
- Institute of Virology, University Hospital Giessen and Marburg, Marburg, Germany
| | - Julie Sellau
- Department of Molecular Biology and Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Mohammad Gharaibeh
- Department of Molecular Biology and Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Department of Basic Veterinary Medical Science, Jordan University of Science and Technology, Faculty of Veterinary Medicine, Irbid, Jordan
| | - Hannelore Lotter
- Department of Molecular Biology and Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Bernhard Fleischer
- Department of Molecular Biology and Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Christian Keller
- Department of Molecular Biology and Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Institute of Virology, University Hospital Giessen and Marburg, Marburg, Germany
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Ueland T, Astrup E, Otterdal K, Lekva T, Janardhanan J, Prakash JAJ, Thomas K, Michelsen AE, Aukrust P, Varghese GM, Damås JK. Secreted Wnt antagonists in scrub typhus. PLoS Negl Trop Dis 2021; 15:e0009185. [PMID: 33914733 PMCID: PMC8112706 DOI: 10.1371/journal.pntd.0009185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 05/11/2021] [Accepted: 01/27/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The mechanisms that control local and systemic inflammation in scrub typhus have only been partially elucidated. The wingless (Wnt) signaling pathways are emerging as important regulators of inflammation and infection, but have not been investigated in scrub typhus. METHODOLOGY/PRINCIPAL FINDINGS Plasma levels of secreted Wnt antagonists (i.e. DKK-1, sFRP-3, WIF-1 and SOST) were analyzed in patients with scrub typhus (n = 129), patients with similar febrile illness without O. tsutsugamushi infection (n = 31), febrile infectious disease controls, and in healthy controls (n = 31) from the same area of South India, and were correlated to markers of inflammation, immune and endothelial cell activation as well as for their association with organ specific dysfunction and mortality in these patients. We found i) Levels of SOST and in particular sFRP-3 and WIF-1 were markedly increased and DKK-1 decreased in scrub typhus patients at admission to the hospital compared to healthy controls. ii) In recovering scrub typhus patients, SOST, sFRP-3 and WIF-1 decreased and DKK-1 increased. iii) SOST was positively correlated with markers of monocyte/macrophage and endothelial/vascular activation as well as with renal dysfunction and poor outcome iv) Finally, regulation of Wnt pathways by O. tsutsugamushi in vitro in monocytes and ex vivo in mononuclear cells isolated from patients with scrub typhus, as evaluated by gene expression studies available in public repositories, revealed markedly attenuated canonical Wnt signaling. CONCLUSIONS/SIGNIFICANCE Our findings suggest that scrub typhus is characterized by attenuated Wnt signaling possibly involving dysregulated levels of several secreted pathway antagonists. The secreted Wnt antagonist SOST was strongly associated with renal dysfunction and poor prognosis in these patients.
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Affiliation(s)
- Thor Ueland
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Faculty of Medicine, University of Oslo, Oslo, Norway
- K.G. Jebsen Thrombosis Research and Expertise Center, University of Tromsø, Tromsø, Norway
- * E-mail:
| | - Elisabeth Astrup
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Institute of Clinical Medicine, Akershus University Hospital, Lørenskog, Norway
| | - Kari Otterdal
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway
| | - Tove Lekva
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway
| | - Jeshina Janardhanan
- Department of Medicine and Infectious Diseases, Christian Medical College, Vellore, Tamil Nadu, India
| | - John A. J. Prakash
- Department of Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Kurien Thomas
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - Annika E. Michelsen
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Pål Aukrust
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Faculty of Medicine, University of Oslo, Oslo, Norway
- Section of Clinical Immunology and Infectious Diseases, Oslo University Hospital Rikshospitalet, Oslo, Norway
| | - George M. Varghese
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jan K. Damås
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Infectious Diseases, St. Olavs Hospital, Trondheim, Norway
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Wangsanut T, Brann KR, Adcox HE, Carlyon JA. Orientia tsutsugamushi modulates cellular levels of NF-κB inhibitor p105. PLoS Negl Trop Dis 2021; 15:e0009339. [PMID: 33857149 PMCID: PMC8078813 DOI: 10.1371/journal.pntd.0009339] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 04/27/2021] [Accepted: 03/29/2021] [Indexed: 11/26/2022] Open
Abstract
Background Scrub typhus is a neglected tropical disease that threatens more than one billion people. If antibiotic therapy is delayed, often due to mis- or late diagnosis, the case fatality rate can increase considerably. Scrub typhus is caused by the obligate intracellular bacterium, Orientia tsutsugamushi, which invades phagocytes and endothelial cells in vivo and diverse tissue culture cell types in vitro. The ability of O. tsutsugamushi to replicate in the cytoplasm indicates that it has evolved to counter eukaryotic host cell immune defense mechanisms. The transcription factor, NF-κB, is a tightly regulated initiator of proinflammatory and antimicrobial responses. Typically, the inhibitory proteins p105 and IκBα sequester the NF-κB p50:p65 heterodimer in the cytoplasm. Canonical activation of NF-κB via TNFα involves IKKβ-mediated serine phosphorylation of IκBα and p105, which leads to their degradation and enables NF-κB nuclear translocation. A portion of p105 is also processed into p50. O. tsutsugamushi impairs NF-κB translocation into the nucleus, but how it does so is incompletely defined. Principal findings Western blot, densitometry, and quantitative RT-PCR analyses of O. tsutsugamushi infected host cells were used to determine if the pathogen’s ability to inhibit NF-κB is linked to modulation of p105. Results demonstrate that p105 levels are elevated several-fold in O. tsutsugamushi infected HeLa and RF/6A cells with only a nominal increase in p50. The O. tsutsugamushi-stimulated increase in p105 is bacterial dose- and protein synthesis-dependent, but does not occur at the level of host cell transcription. While TNFα-induced phosphorylation of p105 serine 932 proceeds unhindered in infected cells, p105 levels remain elevated and NF-κB p65 is retained in the cytoplasm. Conclusions O. tsutsugamushi specifically stabilizes p105 to inhibit the canonical NF-κB pathway, which advances understanding of how it counters host immunity to establish infection. Scrub typhus is a neglected disease that can be fatal and occurs predominantly in the Asia-Pacific, one of the most densely populated regions of the world. Notably, cases continue to emerge outside this area. The etiologic agent is Orientia tsutsugamushi, a bacterial pathogen that infects certain leukocytes and cells that line blood vessels in animals and humans. The success of O. tsutsugamushi to colonize these cells is at least partially attributable to its ability to counter host immunity. In this study, we demonstrate that O. tsutsugamushi stabilizes p105, a mammalian inhibitor of the transcription factor, NF-κB, which is otherwise key for activating proinflammatory and antimicrobial gene expression. O. tsutsugamushi is the first example of a bacterium that inhibits NF-κB by promoting elevated levels of p105 and impairing its degradation. Our findings provide fundamental information that helps explain how this important pathogen has evolved to stealthily establish infection in host cells.
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Affiliation(s)
- Tanaporn Wangsanut
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, Unites States of America
| | - Katelynn R. Brann
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, Unites States of America
| | - Haley E. Adcox
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, Unites States of America
| | - Jason A. Carlyon
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, Unites States of America
- * E-mail:
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Devamani CS, Prakash JAJ, Alexander N, Stone W, Gunasekaran K, Rose W, Schmidt WP. High initial IgG antibody levels against Orientia tsutsugamushi are associated with an increased risk of severe scrub typhus infection. PLoS Negl Trop Dis 2021; 15:e0009283. [PMID: 33735183 PMCID: PMC8009433 DOI: 10.1371/journal.pntd.0009283] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/30/2021] [Accepted: 03/02/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Scrub typhus is a dominant cause of febrile illness in many parts of Asia. Immunity is limited by the great strain diversity of Orientia tsutsugamushi. It is unclear whether previous infection protects from severe infection or enhances the risk. METHODS/PRINCIPAL FINDINGS We studied IgG antibody levels against O. tsutsugamushi at presentation in 636 scrub typhus patients using enzyme-linked immunosorbent assays (ELISA). The association between ELISA optical density (OD) and risk of severe infection was modelled using Poisson regression. OD was categorised as low (<1.0), intermediate (1.0 to 2.9), and high (≥3.0). OD was also modelled as a continuous variable (cubic spline). Median age of cases was 41 years (range 0-85), with 37% having severe infection. Compared to the low category, the age-adjusted risk of severe infection was 1.5 times higher in the intermediate category (95%CI 1.2, 1.9), and 1.3 times higher in the high category (95%CI 1.0, 1.7). The effect was stronger in cases <40 years, doubling the risk in the intermediate and high categories compared to the low category. The effect was more pronounced in cases tested within 7 days of fever onset when IgG ODs are more likely to reflect pre-infection levels. CONCLUSIONS/SIGNIFICANCE Intermediate and high IgG antibody levels at the time of diagnosis are associated with a higher risk of severe scrub typhus infection. The findings may be explained by severe infection eliciting an accelerated IgG response or by previous scrub typhus infection enhancing the severity of subsequent episodes.
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Affiliation(s)
- Carol S. Devamani
- Department of Clinical Microbiology, Christian Medical College, Vellore, India
| | - John A. J. Prakash
- Department of Clinical Microbiology, Christian Medical College, Vellore, India
| | - Neal Alexander
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - William Stone
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Winsley Rose
- Department of Pediatrics and Pediatric Infectious Diseases, Christian Medical College, Vellore, India
| | - Wolf-Peter Schmidt
- Department for Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Trent B, Liang Y, Xing Y, Esqueda M, Wei Y, Cho NH, Kim HI, Kim YS, Shelite TR, Cai J, Sun J, Bouyer DH, Liu J, Soong L. Polarized lung inflammation and Tie2/angiopoietin-mediated endothelial dysfunction during severe Orientia tsutsugamushi infection. PLoS Negl Trop Dis 2020; 14:e0007675. [PMID: 32119672 PMCID: PMC7067486 DOI: 10.1371/journal.pntd.0007675] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 03/12/2020] [Accepted: 01/29/2020] [Indexed: 12/17/2022] Open
Abstract
Orientia tsutsugamushi infection can cause acute lung injury and high mortality in humans; however, the underlying mechanisms are unclear. Here, we tested a hypothesis that dysregulated pulmonary inflammation and Tie2-mediated endothelial malfunction contribute to lung damage. Using a murine model of lethal O. tsutsugamushi infection, we demonstrated pathological characteristics of vascular activation and tissue damage: 1) a significant increase of ICAM-1 and angiopoietin-2 (Ang2) proteins in inflamed tissues and lung-derived endothelial cells (EC), 2) a progressive loss of endothelial quiescent and junction proteins (Ang1, VE-cadherin/CD144, occuludin), and 3) a profound impairment of Tie2 receptor at the transcriptional and functional levels. In vitro infection of primary human EC cultures and serum Ang2 proteins in scrub typhus patients support our animal studies, implying endothelial dysfunction in severe scrub typhus. Flow cytometric analyses of lung-recovered cells further revealed that pulmonary macrophages (MΦ) were polarized toward an M1-like phenotype (CD80+CD64+CD11b+Ly6G-) during the onset of disease and prior to host death, which correlated with the significant loss of CD31+CD45- ECs and M2-like (CD206+CD64+CD11b+Ly6G-) cells. In vitro studies indicated extensive bacterial replication in M2-type, but not M1-type, MΦs, implying the protective and pathogenic roles of M1-skewed responses. This is the first detailed investigation of lung cellular immune responses during acute O. tsutsugamushi infection. It uncovers specific biomarkers for vascular dysfunction and M1-skewed inflammatory responses, highlighting future therapeutic research for the control of this neglected tropical disease.
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Affiliation(s)
- Brandon Trent
- Department of Pathology, 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
| | - Yan Xing
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Marisol Esqueda
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Yang Wei
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - 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
| | - Hong-Il Kim
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Yeon-Sook Kim
- Division of Infectious Diseases, Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Republic of Korea
| | - Thomas R. Shelite
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jiyang Cai
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
| | - Jiaren Sun
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Donald H. Bouyer
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jinjun Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, China
| | - Lynn Soong
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
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Elangovan D, Perumalla S, Rose W, Verghese VP, Mammen J, Gowri MS, Jude Prakash JA. Assessment of two immunoassays for detection of IgM antibodies to scrub typhus using a serum panel. Indian J Med Microbiol 2019; 37:584-586. [PMID: 32436884 DOI: 10.4103/ijmm.ijmm_20_130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Laboratory tests are necessary for diagnosis of scrub typhus (ST) especially in the absence of the distinctive eschar. Performance of an ELISA and ICT (immunochromatography) to detect IgM antibodies to scrub typhus was assessed using a panel of 346 sera chosen from healthy individuals, those with scrub typhus and scrub-typhus like illness. A sensitivity of 98.7% for ST IgM ICT and 97.4% for ST IgM ELISA was observed while specificity was 96.3% for ICT and 95.9% for ELISA. As excellent concordance (98.8%) was noted between the two assays, IgM ICT can be used for rapid diagnosis of scrub typhus. Abbreviations: ST IgM ELISA: Scrub typhus IgM ELISA; ST IgM ICT: Scrub Typhus IgM Immunochromatography, Rapid diagnostic test: RDT.
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Affiliation(s)
- Divyaa Elangovan
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Susmitha Perumalla
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Winsley Rose
- Department of Child Health-III, Christian Medical College, Vellore, Tamil Nadu, India
| | | | - Joy Mammen
- Department of Clinical Pathology, Christian Medical College, Vellore, Tamil Nadu, India
| | - M S Gowri
- Department of Biostatistics, Christian Medical College, Vellore, Tamil Nadu, India
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Trung NV, Hoi LT, Cuong DD, Ha DT, Hoa TM, Lien VN, Hoa NT, Hoa LNM, Huong DT, Bich VTN, van Doorn HR, Nadjm B, Richards AL. Analysis of the 56-kDa type specific antigen gene of Orientia tsutsugamushi from northern Vietnam. PLoS One 2019; 14:e0221588. [PMID: 31469878 PMCID: PMC6716651 DOI: 10.1371/journal.pone.0221588] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 08/09/2019] [Indexed: 11/24/2022] Open
Abstract
Scrub typhus has been documented since 1932 in Vietnam, however, the disease burden of scrub typhus remains poorly understood in the country. We conducted this study to describe the phylogenetic analysis of the 56-kDa type-specific antigen (TSA) gene of Orientia tsutsugamushi associated with PCR positive cases of scrub typhus. Of 116 positive samples, 65 type-specific antigen gene sequences were obtained and classified into 3 genogroups: Karp, Kato and Gilliam. The Karp genogroup was the most frequently detected phylogenetic cluster in the study with 30 samples (46%), followed by Kato and Gilliam with 20 (31%) and 15 (23%), respectively. All sequences showed 94–100% nucleotide similarity to reference sequences collected in the central part of Vietnam in 2017. Patients infected with Karp genogroup were more likely to have significant thrombocytopenia than the other genogroups. These results suggest that any scrub typhus vaccine considered for use in Vietnam should provide protection against each of these 3 genogroups.
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Affiliation(s)
- Nguyen Vu Trung
- National Hospital for Tropical Diseases, Hanoi, Vietnam
- Hanoi Medical University, Hanoi, Vietnam
| | - Le Thi Hoi
- National Hospital for Tropical Diseases, Hanoi, Vietnam
| | | | | | - Tran Mai Hoa
- National Hospital for Tropical Diseases, Hanoi, Vietnam
| | - Vu Ngoc Lien
- National Hospital for Tropical Diseases, Hanoi, Vietnam
| | | | | | | | - Vu Thi Ngoc Bich
- Oxford University Clinical Research Unit, Wellcome Trust Asia Program, Hanoi, Vietnam
| | - H. Rogier van Doorn
- Oxford University Clinical Research Unit, Wellcome Trust Asia Program, Hanoi, Vietnam
| | - Behzad Nadjm
- Oxford University Clinical Research Unit, Wellcome Trust Asia Program, Hanoi, Vietnam
| | - Allen L. Richards
- Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
- * E-mail:
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Bora T, Khan SA. Evaluation of Th1 and Th2 immune response in clinical and sub-clinical scrub typhus infection. Hum Immunol 2019; 80:503-509. [PMID: 30904436 DOI: 10.1016/j.humimm.2019.03.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/18/2019] [Accepted: 03/18/2019] [Indexed: 11/19/2022]
Abstract
Scrub typhus (ST), caused by a gram negative intracellular bacteria- Orientia tsutsugamushi, is one among the leading causes of febrile illness across Southeast Asia, including India. Clinical presentation can vary from asymptomatic to severely fatal. Th1-cell mediated immunity has been suggested to play an important role against ST infection in animal models. However, human data on protective immunity are limited. The present study was undertaken to identify host immune correlates that could confer protection in individuals that remain clinically asymptomatic/sub-clinical. Serum cytokine profiling and mRNA expression levels of Th1 (TNF-α, IFN-γ, IL-2) and Th2 (IL-10, IL-6, IL-4) cytokines was studied amongst the clinical and sub-clinical infections. It was observed that a Th1/Th2 pattern is not involved in human ST infection irrespective of being a symptomatic or asymptomatic presentation. However, significant difference was observed in IL-10 serum and gene expression levels. This study suggests a possible role of IL-10 in disease phenotypic presentation. Over-production of IL-10 was found to be a significant factor contributing to the severity of the disease whereas a protective immune mechanism might exist with a low level of IL-10 in ST infection.
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Affiliation(s)
- Trishna Bora
- Medical Entomology, Arbovirology and Rickettsial Disease Division, Indian Council of Medical Research- Regional Medical Research Centre, N.E. Region, Post box no. 105, Dibrugarh-786001, Assam, India
| | - Siraj Ahmed Khan
- Medical Entomology, Arbovirology and Rickettsial Disease Division, Indian Council of Medical Research- Regional Medical Research Centre, N.E. Region, Post box no. 105, Dibrugarh-786001, Assam, India.
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Saraswati K, Phanichkrivalkosil M, Day NPJ, Blacksell SD. The validity of diagnostic cut-offs for commercial and in-house scrub typhus IgM and IgG ELISAs: A review of the evidence. PLoS Negl Trop Dis 2019; 13:e0007158. [PMID: 30716070 PMCID: PMC6382213 DOI: 10.1371/journal.pntd.0007158] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 02/20/2019] [Accepted: 01/15/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Scrub typhus is a neglected tropical disease that causes acute febrile illness. Diagnosis is made based upon serology, or detection of the causative agent-Orientia tsutsugamushi-using PCR or in vitro isolation. The enzyme-linked immunosorbent assay (ELISA) is an objective and reproducible means of detecting IgM or IgG antibodies. However, lack of standardization in ELISA methodology, as well as in the choice of reference test with which the ELISA is compared, calls into question the validity of cut-offs used in diagnostic accuracy studies and observational studies. METHODOLOGY/PRINCIPAL FINDINGS A PubMed search and manual screening of reference lists identified 46 studies that used ELISA antibody cut-offs to diagnose scrub typhus patients, 22 of which were diagnostic accuracy studies. Overall, 22 studies (47.8%) provided little to no explanation as to how the ELISA cut-off was derived, and 7 studies (15.2%) did not even state the cut-off used. Variation was seen locally in reference standards used, in terms of both the diagnostic test and cut-off titer. Furthermore, with the exception of studies using ELISAs manufactured by InBios, there was no standardization of the selection of antigenic strains. As a result, no consensus was found for determining a cut-off, ELISA methodology, or for a single value diagnostic cut-off. CONCLUSIONS/SIGNIFICANCE We have concluded that there is a lack of consensus in the determination of a cut-off. We recommend interpreting the results from these studies with caution. Further studies will need to be performed at each geographic location to determine region-specific cut-offs, taking into consideration background antibody levels to discriminate true disease from healthy individuals.
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Affiliation(s)
- Kartika Saraswati
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Meghna Phanichkrivalkosil
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas P. J. Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Stuart D. Blacksell
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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Ge H, Farris CM, Tong M, Maina A, Richards AL. Transcriptional profiles of cytokines and chemokines reveal important pro-inflammatory response from endothelial cells during Orientia tsutsugamushi infection. Microbes Infect 2019; 21:313-320. [PMID: 30684683 DOI: 10.1016/j.micinf.2019.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 01/14/2019] [Indexed: 01/18/2023]
Abstract
Endothelial cells (EC) are key targets during Orientia tsutsugamushi infection. Knowledge of the pro-inflammatory response against O. tsutsugamushi by ECs is limited. The aim of the present study was to characterize the pro-inflammatory transcriptional response during the first 24 h of infection of the human dermal microvascular endothelial cell line with O. tsutsugamushi Karp by examining five-time points. The transcriptional profiles of 84 genes including cytokines, chemokines, growth factors, and TNF receptor superfamily genes were studied using a RT-PCR array. We identified 40 of the 84 genes that were up or down modulated during the early O. tsutsugamushi infection that differed remarkably from genes of non-infected cells. The modulated genes included: the interleukins (IL-1α/β, IL-4, IL-6, IL-7, IL-10, IL-11, IL-18, and IL-24), chemokines (CXCL8, CCL2/MCP1, CCL5/RANTES, and CCL17), growth factors (NODAL, CNTF, and CSF2/GM-CSF), and TNFSF13B. IL-1β, IL-4, and IL-11 were highly induced at one hour post infection, whereas, CCL17 was profoundly up-regulated and IFNα2 was greatly down-regulated during the entire 24-hour time course. These results provide insight into the early pro-inflammatory response of endothelial cells to O. tsutsugamushi infection and indicate their potential role in the pathophysiology of the host's initial response to O. tsutsugamushi infection.
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Affiliation(s)
- Hong Ge
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, USA
| | - Christina M Farris
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, USA; US Naval Medical Research Unit No. 2, Phnom Penh, Cambodia
| | - Min Tong
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, USA
| | - Alice Maina
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, USA
| | - Allen L Richards
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, USA.
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11
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Evans SM, Rodino KG, Adcox HE, Carlyon JA. Orientia tsutsugamushi uses two Ank effectors to modulate NF-κB p65 nuclear transport and inhibit NF-κB transcriptional activation. PLoS Pathog 2018; 14:e1007023. [PMID: 29734393 PMCID: PMC5957444 DOI: 10.1371/journal.ppat.1007023] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 05/17/2018] [Accepted: 04/11/2018] [Indexed: 01/05/2023] Open
Abstract
Orientia tsutsugamushi causes scrub typhus, a potentially fatal infection that threatens over one billion people. Nuclear translocation of the transcription factor, NF-κB, is the central initiating cellular event in the antimicrobial response. Here, we report that NF-κB p65 nuclear accumulation and NF-κB-dependent transcription are inhibited in O. tsutsugamushi infected HeLa cells and/or primary macrophages, even in the presence of TNFα. The bacterium modulates p65 subcellular localization by neither degrading it nor inhibiting IκBα degradation. Rather, it exploits host exportin 1 to mediate p65 nuclear export, as this phenomenon is leptomycin B-sensitive. O. tsutsugamushi antagonizes NF-κB-activated transcription even when exportin 1 is inhibited and NF-κB consequently remains in the nucleus. Two ankyrin repeat-containing effectors (Anks), Ank1 and Ank6, each of which possess a C-terminal F-box and exhibit 58.5% amino acid identity, are linked to the pathogen's ability to modulate NF-κB. When ectopically expressed, both translocate to the nucleus, abrogate NF-κB-activated transcription in an exportin 1-independent manner, and pronouncedly reduce TNFα-induced p65 nuclear levels by exportin 1-dependent means. Flag-tagged Ank 1 and Ank6 co-immunoprecipitate p65 and exportin 1. Both also bind importin β1, a host protein that is essential for the classical nuclear import pathway. Importazole, which blocks importin β1 activity, abrogates Ank1 and Ank6 nuclear translocation. The Ank1 and Ank6 regions that bind importin β1 also mediate their transport into the nucleus. Yet, these regions are distinct from those that bind p65/exportin 1. The Ank1 and Ank6 F-box and the region that lies between it and the ankyrin repeat domain are essential for blocking p65 nuclear accumulation. These data reveal a novel mechanism by which O. tsutsugamushi modulates the activity and nuclear transport of NF-κB p65 and identify the first microbial proteins that co-opt both importin β1 and exportin 1 to antagonize a critical arm of the antimicrobial response.
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Affiliation(s)
- Sean M. Evans
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, United States of America
| | - Kyle G. Rodino
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, United States of America
| | - Haley E. Adcox
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, United States of America
| | - Jason A. Carlyon
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, United States of America
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12
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Kocher C, Jiang J, Morrison AC, Castillo R, Leguia M, Loyola S, Ampuero JS, Cespedes M, Halsey ES, Bausch DG, Richards AL. Serologic Evidence of Scrub Typhus in the Peruvian Amazon. Emerg Infect Dis 2018; 23:1389-1391. [PMID: 28726619 PMCID: PMC5547797 DOI: 10.3201/eid2308.170050] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Using a large, passive, febrile surveillance program in Iquitos, Peru, we retrospectively tested human blood specimens for scrub typhus group orientiae by ELISA, immunofluorescence assay, and PCR. Of 1,124 participants, 60 (5.3%) were seropositive, and 1 showed evidence of recent active infection. Our serologic data indicate that scrub typhus is present in the Peruvian Amazon.
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13
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Tshokey T, Graves S, Tshering D, Phuntsho K, Tshering K, Stenos J. Scrub Typhus Outbreak in a Remote Primary School, Bhutan, 2014. Emerg Infect Dis 2018; 23:1412-1414. [PMID: 28726604 PMCID: PMC5547789 DOI: 10.3201/eid2308.162021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Scrub typhus in Bhutan was first reported in 2009. We investigated an outbreak of scrub typhus in a remote primary school during August–October 2014. Delay in recognition and treatment resulted in 2 deaths from meningoencephalitis. Scrub typhus warrants urgent public health interventions in Bhutan.
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Varghese GM, Rajagopal VM, Trowbridge P, Purushothaman D, Martin SJ. Kinetics of IgM and IgG antibodies after scrub typhus infection and the clinical implications. Int J Infect Dis 2018; 71:53-55. [PMID: 29653201 PMCID: PMC5985369 DOI: 10.1016/j.ijid.2018.03.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 03/23/2018] [Accepted: 03/30/2018] [Indexed: 11/18/2022] Open
Abstract
The kinetics of IgM and IgG post scrub typhus infection remain elusive. Scrub typhus patients were followed up to study antibody kinetics. IgM remained above the threshold for 12 months. IgG reached a peak at 10 months and remained above the threshold for 36 months. Paired IgM samples are required for accurate diagnosis.
Objectives The serological detection of IgM antibodies is the most widely used test to diagnose scrub typhus infection. However, the kinetics of IgM and IgG antibodies post-infection remain elusive, which could contribute to false positivity. The objective of this study was to document the nature of the evolution of these antibody titres after infection. Methods Adult patients previously confirmed to have scrub typhus by IgM ELISA, positive PCR, or both, were included in this cross-sectional study. The levels of IgM and IgG antibodies in serum samples were tested using an ELISA and the distribution curve was plotted. Results Two hundred and three patients were included in this study. Post-infection serum sampling was done between 1 month and 46 months after documented infection. IgM levels declined gradually but remained elevated above the diagnostic cut-off for up to 12 months post-infection. However, IgG levels continued to rise reaching a peak at 10 months, followed by a gradual decline over several months. In the majority of cases, the IgG levels remained above the cut-off threshold for more than 36 months. Conclusions Clinicians need to be cautious in using a single serum sample for the detection of IgM to diagnose scrub typhus, as it remains elevated for up to 12 months after the infection, whereas the serum IgG level could be used as an indicator of past infection.
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Affiliation(s)
- George M Varghese
- Department of Infectious Diseases, Christian Medical College, Vellore 632004, Tamil Nadu, India.
| | | | - Paul Trowbridge
- Department of Infectious Diseases, Christian Medical College, Vellore 632004, Tamil Nadu, India
| | - Divya Purushothaman
- Department of Infectious Diseases, Christian Medical College, Vellore 632004, Tamil Nadu, India
| | - Sherry Joseph Martin
- Department of Infectious Diseases, Christian Medical College, Vellore 632004, Tamil Nadu, India
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15
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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16
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Sunyakumthorn P, Somponpun SJ, Im-erbsin R, Anantatat T, Jenjaroen K, Dunachie SJ, Lombardini ED, Burke RL, Blacksell SD, Jones JW, Mason CJ, Richards AL, Day NPJ, Paris DH. Characterization of the rhesus macaque (Macaca mulatta) scrub typhus model: Susceptibility to intradermal challenge with the human pathogen Orientia tsutsugamushi Karp. PLoS Negl Trop Dis 2018. [PMID: 29522521 PMCID: PMC5862536 DOI: 10.1371/journal.pntd.0006305] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Scrub typhus is an important endemic disease in tropical Asia caused by Orientia tsutsugamushi for which no effective broadly protective vaccine is available. The successful evaluation of vaccine candidates requires well-characterized animal models and a better understanding of the immune response against O. tsutsugamushi. While many animal species have been used to study host immunity and vaccine responses in scrub typhus, only limited data exists in non-human primate (NHP) models. METHODOLOGY/PRINCIPLE FINDINGS In this study we evaluated a NHP scrub typhus disease model based on intradermal inoculation of O. tsutsugamushi Karp strain in rhesus macaques (n = 7). After an intradermal inoculation with 106 murine LD50 of O. tsutsugamushi at the anterior thigh (n = 4) or mock inoculum (n = 3), a series of time course investigations involving hematological, biochemical, molecular and immunological assays were performed, until day 28, when tissues were collected for pathology and immunohistochemistry. In all NHPs with O. tsutsugamushi inoculation, but not with mock inoculation, the development of a classic eschar with central necrosis, regional lymphadenopathy, and elevation of body temperature was observed on days 7-21 post inoculation (pi); bacteremia was detected by qPCR on days 6-18 pi; and alteration of liver enzyme function and increase of white blood cells on day 14 pi. Immune assays demonstrated raised serum levels of soluble cell adhesion molecules, anti-O. tsutsugamushi-specific antibody responses (IgM and IgG) and pathogen-specific cell-mediated immune responses in inoculated macaques. The qPCR assays detected O. tsutsugamushi in eschar, spleen, draining and non-draining lymph nodes, and immuno-double staining demonstrated intracellular O. tsutsugamushi in antigen presenting cells of eschars and lymph nodes. CONCLUSIONS/SIGNIFICANCE These data show the potential of using rhesus macaques as a scrub typhus model, for evaluation of correlates of protection in both natural and vaccine induced immunity, and support the evaluation of future vaccine candidates against scrub typhus.
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Affiliation(s)
- Piyanate Sunyakumthorn
- Department of Veterinary Medicine, United States Army Medical Directorate, Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Suwit J. Somponpun
- Department of Veterinary Medicine, United States Army Medical Directorate, Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok, Thailand
| | - Rawiwan Im-erbsin
- Department of Veterinary Medicine, United States Army Medical Directorate, Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok, Thailand
| | - Tippawan Anantatat
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Kemajittra Jenjaroen
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Susanna J. Dunachie
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Eric D. Lombardini
- Department of Veterinary Medicine, United States Army Medical Directorate, Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok, Thailand
| | - Robin L. Burke
- Department of Veterinary Medicine, United States Army Medical Directorate, Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok, Thailand
| | - Stuart D. Blacksell
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom
| | - James W. Jones
- Department of Veterinary Medicine, United States Army Medical Directorate, Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok, Thailand
| | - Carl J. Mason
- Department of Veterinary Medicine, United States Army Medical Directorate, Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok, Thailand
| | - Allen L. Richards
- Viral & Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States of America
- Preventive Medicine and Biostatistics Department, Uniformed Services University of the Health Sciences, Bethesda, MD, United States of America
| | - Nicholas P. J. Day
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom
| | - Daniel H. Paris
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom
- Department of Medicine, Swiss Tropical and Public Health Institute, Basel, Switzerland
- Faculty of Medicine, University of Basel, Basel, Switzerland
- * E-mail:
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Rajapakse S, Weeratunga P, Sivayoganathan S, Fernando SD. Clinical manifestations of scrub typhus. Trans R Soc Trop Med Hyg 2018; 111:43-54. [PMID: 28449088 DOI: 10.1093/trstmh/trx017] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 04/11/2017] [Indexed: 01/10/2023] Open
Abstract
The mite-borne rickettsial zoonosis scrub typhus is widely prevalent in parts of Southeast and Far East Asia, and northern Australia. The disease is an acute febrile illness, associated with rash and often an eschar, which responds dramatically to treatment with antibiotics. In some cases it results in a serious illness leading to multiple organ involvement and death. The disease manifestations are thought to result from a systemic vasculitis, caused by both direct effects of the organisms as well as an exaggerated immune response, although little is understood about its pathogenesis. A wide spectrum of clinical manifestations, affecting nearly every organ system, have been described with scrub typhus. Some of these manifestations are serious and life threatening. In this systematic review, we summarise the typical and atypical manifestations of scrub typhus reported in the literature. Awareness of these unusual manifestations will hopefully guide clinicians towards diagnosing the condition early, and initiating early appropriate antibiotics and other supportive measures.
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Affiliation(s)
- Senaka Rajapakse
- Tropical Medicine Research Unit, Department of Clinical Medicine, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo 08, Sri Lanka
| | - Praveen Weeratunga
- University Medical Unit, National Hospital, Regent Street, Colombo 08, Sri Lanka
| | - Sriharan Sivayoganathan
- Tropical Medicine Research Unit, Department of Clinical Medicine, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo 08, Sri Lanka
| | - Sumadhya Deepika Fernando
- Department of Parasitology, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo 08, Sri Lanka
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Sumonwiriya M, Paris DH, Sunyakumthorn P, Anantatat T, Jenjaroen K, Chumseng S, Im-erbsin R, Tanganuchitcharnchai A, Jintaworn S, Blacksell SD, Chowdhury FR, Kronsteiner B, Teparrukkul P, Burke RL, Lombardini ED, Richards AL, Mason CJ, Jones JW, Day NPJ, Dunachie SJ. Strong interferon-gamma mediated cellular immunity to scrub typhus demonstrated using a novel whole cell antigen ELISpot assay in rhesus macaques and humans. PLoS Negl Trop Dis 2017; 11:e0005846. [PMID: 28892515 PMCID: PMC5608426 DOI: 10.1371/journal.pntd.0005846] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 09/21/2017] [Accepted: 08/01/2017] [Indexed: 01/30/2023] Open
Abstract
Scrub typhus is a febrile infection caused by the obligate intracellular bacterium Orientia tsutsugamushi, which causes significant morbidity and mortality across the Asia-Pacific region. The control of this vector-borne disease is challenging due to humans being dead-end hosts, vertical maintenance of the pathogen in the vector itself, and a potentially large rodent reservoir of unclear significance, coupled with a lack of accurate diagnostic tests. Development of an effective vaccine is highly desirable. This however requires better characterization of the natural immune response of this neglected but important disease. Here we implement a novel IFN-γ ELISpot assay as a tool for studying O. tsutsugamushi induced cellular immune responses in an experimental scrub typhus rhesus macaque model and human populations. Whole cell antigen for O. tsutsugamushi (OT-WCA) was prepared by heat inactivation of Karp-strain bacteria. Rhesus macaques were infected intradermally with O. tsutsugamushi. Freshly isolated peripheral blood mononuclear cells (PBMC) from infected (n = 10) and uninfected animals (n = 5) were stimulated with OT-WCA, and IFN-γ secreting cells quantitated by ELISpot assay at five time points over 28 days. PBMC were then assayed from people in a scrub typhus-endemic region of Thailand (n = 105) and responses compared to those from a partially exposed population in a non-endemic region (n = 14), and to a naïve population in UK (n = 12). Mean results at Day 0 prior to O. tsutsugamushi infection were 12 (95% CI 0–25) and 15 (2–27) spot-forming cells (SFC)/106 PBMC for infected and control macaques respectively. Strong O. tsutsugamushi-specific IFN-γ responses were seen post infection, with ELISpot responses 20-fold higher than baseline at Day 7 (mean 235, 95% CI 200–270 SFC/106 PBMC), 105-fold higher at Day 14 (mean 1261, 95% CI 1,097–1,425 SFC/106 PBMC), 125-fold higher at Day 21 (mean 1,498, 95% CI 1,496–1,500 SFC/106 PBMC) and 118-fold higher at Day 28 (mean 1,416, 95% CI 1,306–1,527 SFC/106 PBMC). No significant change was found in the control group at any time point compared to baseline. Humans from a scrub typhus endemic region of Thailand had mean responses of 189 (95% CI 88–290) SFC/106 PBMC compared to mean responses of 40 (95% CI 9–71) SFC/106 PBMC in people from a non-endemic region and 3 (95% CI 0–7) SFC/106 PBMC in naïve controls. In summary, this highly sensitive assay will enable field immunogenicity studies and further characterization of the host response to O. tsutsugamushi, and provides a link between human and animal models to accelerate vaccine development. Scrub typhus is a disease caused by bacteria that invade cells in our immune system and blood vessels. It is transmitted by mites and is treatable with antibiotics. Unfortunately diagnosis is difficult and requires techniques that are not easily accessible everywhere. Currently, there is no scrub typhus vaccine available. In order to improve diagnostics and vaccine development in future, we need to better understand our immune response against these bacteria. In this study, we developed a test where these bacteria were killed and prepared by a new purification method to stimulate the immune cells in our blood -not antibodies. We evaluated this test in hospitalized patients with scrub typhus disease and also in non-human primates to study the responses over time. The test proved to be very accurate and useful to study natural immune responses, and we found differences in responses in areas where scrub typhus is common, compared to areas where it is not common. This test will allow us to investigate the immune response to scrub typhus more in-depth in the future, and will support the development of better diagnostic tests and vaccines against scrub typhus.
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Affiliation(s)
| | - Daniel H. Paris
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Department of Medicine, Swiss Tropical and Public Health Institute, Basel, Switzerland
- Faculty of Medicine, University of Basel, Basel, Switzerland
- * E-mail:
| | - Piyanate Sunyakumthorn
- Department of Veterinary Medicine, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Tippawan Anantatat
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Kemajittra Jenjaroen
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Suchintana Chumseng
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Rawiwan Im-erbsin
- Department of Veterinary Medicine, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | | | - Suthatip Jintaworn
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Stuart D. Blacksell
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Fazle R. Chowdhury
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom
| | - Barbara Kronsteiner
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom
| | - Prapit Teparrukkul
- Department of Medicine, Sappasithiprasong Hospital, Ubon Ratchathani, Thailand
| | - Robin L. Burke
- Department of Veterinary Medicine, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Eric D. Lombardini
- Department of Veterinary Medicine, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Allen L. Richards
- Department of Viral & Rickettsial Diseases, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Preventive Medicine and Biometrics Department, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Carl J. Mason
- Department of Enteric Diseases, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - James W. Jones
- Department of Veterinary Medicine, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
- Department of Enteric Diseases, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Nicholas P. J. Day
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Susanna J. Dunachie
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom
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Choi S, Jeong HJ, Hwang KJ, Gill B, Ju YR, Lee YS, Lee J. A Recombinant 47-kDa Outer Membrane Protein Induces an Immune Response against Orientia tsutsugamushi Strain Boryong. Am J Trop Med Hyg 2017; 97:30-37. [PMID: 28719308 PMCID: PMC5508880 DOI: 10.4269/ajtmh.15-0771] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 12/04/2016] [Indexed: 11/10/2022] Open
Abstract
We investigated the 47-kDa outer membrane protein (OMP), which is a periplasmic serine protease and an antigenic major surface protein of Orientia tsutsugamushi, as a vaccine candidate. We developed a conventional subunit vaccine expressing recombinant 47-kDa OMP (rec47) and a DNA vaccine (p47). In mouse immunization experiments, intranasal immunization with rec47 alone or with rec47 plus heat-labile enterotoxin B subunit from Escherichia coli or plus cholera toxin (CT) as adjuvants induced a higher amount of rec47-specific antibodies than intramuscular immunization with p47 alone or with p47 plus pBOOST2-samIRF7/3 (pB) as adjuvant. Moreover, the combination of rec47 and CT induced a strong cellular immune response to 47-kDa OMP, as demonstrated by a spleen cell proliferation assay, and also induced Th1- and Th2-type cytokine production, as demonstrated by a cytokine enzyme-linked immunosorbent assay. Intranasal immunization with rec47 plus CT was the most effective method for the induction of humoral and cell-mediated immune responses. Furthermore, relatively strong protection against homologous O. tsutsugamushi strain Boryong challenge was observed in mice immunized with rec47 plus CT. Therefore, 47-kDa OMP is an attractive candidate for developing a prophylactic vaccine against scrub typhus by O. tsutsugamushi infection.
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Affiliation(s)
- Sangho Choi
- Division of Zoonoses, Center for Immunology and Pathology, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju, Korea
| | - Hang Jin Jeong
- Division of Zoonoses, Center for Immunology and Pathology, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju, Korea
| | - Kyu-Jam Hwang
- Division of Zoonoses, Center for Immunology and Pathology, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju, Korea
| | - Byoungchul Gill
- Division of Zoonoses, Center for Immunology and Pathology, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju, Korea
| | - Young Ran Ju
- Division of Zoonoses, Center for Immunology and Pathology, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju, Korea
| | - Yeong Seon Lee
- Division of Zoonoses, Center for Immunology and Pathology, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju, Korea
| | - Jeongmin Lee
- Division of Zoonoses, Center for Immunology and Pathology, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju, Korea
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Faruque LI, Zaman RU, Gurley ES, Massung RF, Alamgir ASM, Galloway RL, Powers AM, Bai Y, Kosoy M, Nicholson WL, Rahman M, Luby SP. Prevalence and clinical presentation of Rickettsia, Coxiella, Leptospira, Bartonella and chikungunya virus infections among hospital-based febrile patients from December 2008 to November 2009 in Bangladesh. BMC Infect Dis 2017; 17:141. [PMID: 28193163 PMCID: PMC5307764 DOI: 10.1186/s12879-017-2239-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 02/02/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND We conducted a study to identify Rickettsia, Coxiella, Leptospira, Bartonella, and Chikungunya virus infections among febrile patients presenting at hospitals in Bangladesh. METHODS We collected blood samples from patients at six tertiary hospitals from December 2008 to November 2009 and performed laboratory tests at the United States Centers for Disease Control and Prevention (CDC). RESULTS Out of 720 enrolled patients, 263 (37%) were infected with Rickettsia; 132 patients had immunofluorescence antibody titer >64 against spotted fever, 63 patients against scrub typhus fever and 10 patients against typhus fever. Ten patients were identified with Coxiella. We isolated Leptospira from two patients and Bartonella from one patient. Ten patients had antibodies against Chikungunya virus. The proportion of patients who died was higher with rickettsial fever (5%) compared to those without a diagnosis of rickettsial infection (2%). None of the patients were initially diagnosed with rickettsial fever. CONCLUSIONS Rickettsial infections are frequent yet under-recognized cause of febrile illness in Bangladesh. Clinical guidelines should be revised so that local clinicians can diagnose rickettsial infections and provide appropriate drug treatment.
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Affiliation(s)
- Labib Imran Faruque
- International Centre for Diarrheal Diseases Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Rashid Uz Zaman
- International Centre for Diarrheal Diseases Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Emily S. Gurley
- International Centre for Diarrheal Diseases Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | | | - A. S. M. Alamgir
- Institute of Epidemiology, Disease Control and Research (IEDCR), Dhaka, Bangladesh
| | | | - Ann M. Powers
- Centers for Disease Control and Prevention (CDC), Atlanta, GA USA
| | - Ying Bai
- Centers for Disease Control and Prevention (CDC), Atlanta, GA USA
| | - Michael Kosoy
- Centers for Disease Control and Prevention (CDC), Atlanta, GA USA
| | | | - Mahmudur Rahman
- Institute of Epidemiology, Disease Control and Research (IEDCR), Dhaka, Bangladesh
| | - Stephen P. Luby
- International Centre for Diarrheal Diseases Research, Bangladesh (icddr,b), Dhaka, Bangladesh
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21
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Hauptmann M, Kolbaum J, Lilla S, Wozniak D, Gharaibeh M, Fleischer B, Keller CA. Protective and Pathogenic Roles of CD8+ T Lymphocytes in Murine Orientia tsutsugamushi Infection. PLoS Negl Trop Dis 2016; 10:e0004991. [PMID: 27606708 PMCID: PMC5015871 DOI: 10.1371/journal.pntd.0004991] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 08/19/2016] [Indexed: 01/12/2023] Open
Abstract
T cells are known to contribute to immune protection against scrub typhus, a potentially fatal infection caused by the obligate intracellular bacterium Orientia (O.) tsutsugamushi. However, the contribution of CD8+ T cells to protection and pathogenesis during O. tsutsugamushi infection is still unknown. Using our recently developed BALB/c mouse model that is based on footpad inoculation of the human-pathogenic Karp strain, we show that activated CD8+ T cells infiltrate spleen and lung during the third week of infection. Depletion of CD8+ T cells with monoclonal antibodies resulted in uncontrolled pathogen growth and mortality. Adoptive transfer of CD8+ T cells from infected animals protected naïve BALB/c mice from lethal outcome of intraperitoneal challenge. In C57Bl/6 mice, the pulmonary lymphocyte compartment showed an increased percentage of CD8+ T cells for at least 135 days post O. tsutsugamushi infection. Depletion of CD8+ T cells at 84 days post infection caused reactivation of bacterial growth. In CD8+ T cell-deficient beta 2-microglobulin knockout mice, bacterial replication was uncontrolled, and all mice succumbed to the infection, despite higher serum IFN-γ levels and stronger macrophage responses in liver and lung. Moreover, we show that CD8+ T cells but not NKT cells were required for hepatocyte injury: elevated concentrations of serum alanine aminotransferase and infection-induced subcapsular necrotic liver lesions surrounded by macrophages were found in C57Bl/6 and CD1d-deficient mice, but not in beta 2-microglobulin knockout mice. In the lungs, peribronchial macrophage infiltrations also depended on CD8+ T cells. In summary, our results demonstrate that CD8+ T cells restrict growth of O. tsutsugamushi during acute and persistent infection, and are required to protect from lethal infections in BALB/c and C57BL/6 mice. However, they also elicit specific pathologic tissue lesions in liver and lung.
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Affiliation(s)
- Matthias Hauptmann
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Julia Kolbaum
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Stefanie Lilla
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - David Wozniak
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Mohammad Gharaibeh
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Bernhard Fleischer
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Institute for Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian A. Keller
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
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22
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Soong L, Mendell NL, Olano JP, Rockx-Brouwer D, Xu G, Goez-Rivillas Y, Drom C, Shelite TR, Valbuena G, Walker DH, Bouyer DH. An Intradermal Inoculation Mouse Model for Immunological Investigations of Acute Scrub Typhus and Persistent Infection. PLoS Negl Trop Dis 2016; 10:e0004884. [PMID: 27479584 PMCID: PMC4968841 DOI: 10.1371/journal.pntd.0004884] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Accepted: 07/07/2016] [Indexed: 01/08/2023] Open
Abstract
Scrub typhus is a neglected tropical disease, caused by Orientia tsutsugamushi, a Gram-negative bacterium that is transmitted to mammalian hosts during feeding by Leptotrombidium mites and replicates predominantly within endothelial cells. Most studies of scrub typhus in animal models have utilized either intraperitoneal or intravenous inoculation; however, there is limited information on infection by the natural route in murine model skin or its related early host responses. Here, we developed an intradermal (i.d.) inoculation model of scrub typhus and focused on the kinetics of the host responses in the blood and major infected organs. Following ear inoculation with 6 x 104 O. tsutsugamushi, mice developed fever at 11-12 days post-infection (dpi), followed by marked hypothermia and body weight loss at 14-19 dpi. Bacteria in blood and tissues and histopathological changes were detected around 9 dpi and peaked around 14 dpi. Serum cytokine analyses revealed a mixed Th1/Th2 response, with marked elevations of MCP-1/CCL2, MIP-1α/CCL3 and IL-10 at 9 dpi, followed by increased concentrations of pro-inflammatory markers (IL-6, IL-12, IFN-γ, G-CSF, RANTES/CCL5, KC/CCL11, IL-1α/β, IL-2, TNF-α, GM-CSF), as well as modulatory cytokines (IL-9, IL-13). Cytokine levels in lungs had similar elevation patterns, except for a marked reduction of IL-9. The Orientia 47-kDa gene and infectious bacteria were detected in several organs for up to 84 dpi, indicating persistent infection. This is the first comprehensive report of acute scrub typhus and persistent infection in i.d.-inoculated C57BL/6 mice. This is a significant improvement over current murine models for Orientia infection and will permit detailed studies of host immune responses and infection control interventions.
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Affiliation(s)
- Lynn Soong
- 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, School of Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America
- 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, School of Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Juan P. Olano
- 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, School of Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Dedeke Rockx-Brouwer
- 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, School of Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Guang Xu
- 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, School of Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Yenny Goez-Rivillas
- 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, School of Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Claire Drom
- 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, School of Medicine, 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
| | - Gustavo 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, School of Medicine, 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, School of Medicine, 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, School of Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America
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Thiga JW, Mutai BK, Eyako WK, Ng'ang'a Z, Jiang J, Richards AL, Waitumbi JN. High seroprevalence of antibodies against spotted fever and scrub typhus bacteria in patients with febrile Illness, Kenya. Emerg Infect Dis 2015; 21:688-91. [PMID: 25811219 PMCID: PMC4378494 DOI: 10.3201/eid2104.141387] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Serum samples from patients in Kenya with febrile illnesses were screened for antibodies against bacteria that cause spotted fever, typhus, and scrub typhus. Seroprevalence was 10% for spotted fever group, <1% for typhus group, and 5% for scrub typhus group. Results should help clinicians expand their list of differential diagnoses for undifferentiated fevers.
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24
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Watthanaworawit W, Turner P, Turner C, Tanganuchitcharnchai A, Jintaworn S, Hanboonkunupakarn B, Richards AL, Day NPJ, Blacksell SD, Nosten F. Diagnostic Accuracy Assessment of Immunochromatographic Tests for the Rapid Detection of Antibodies Against Orientia tsutsugamushi Using Paired Acute and Convalescent Specimens. Am J Trop Med Hyg 2015; 93:1168-1171. [PMID: 26458778 PMCID: PMC4674230 DOI: 10.4269/ajtmh.15-0435] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/21/2015] [Indexed: 11/22/2022] Open
Abstract
We assessed the diagnostic accuracy of two immunochromatographic tests (ICTs), the Access Bio CareStart Scrub Typhus test (Somerset, NJ) (IgM), and the SD BIOLINE Tsutsugamushi test (Kyonggi-do, Republic of Korea) (IgG, IgM, or IgA) compared with indirect immunofluorescence assay (IFA) and real-time PCR results as reference tests using 86 paired acute and convalescent specimens from febrile patients. The sensitivity and specificity of the CareStart test were 23.3% (95% confidence interval [CI]: 11.8–38.6) and 81.4% (95% CI: 66.6–91.6), respectively, for acute specimens and 32.6% (95% CI: 19.1–48.5) and 79.1% (95% CI: 64.0–90.0), respectively, for convalescent specimens. For the SD BIOLINE test, sensitivity and specificity were 20.9% (95% CI: 10.0–36.0) and 74.4% (95% CI: 58.8–86.5), respectively, for acute specimens and 76.7% (95% CI: 61.4–88.2) and 76.7% (95% CI: 61.4–88.2), respectively, for convalescent specimens. The poor sensitivity obtained for both ICTs during this study when performed on acute specimens highlights the difficulties in prompt diagnosis of scrub typhus.
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Affiliation(s)
- Wanitda Watthanaworawit
- *Address correspondence to Wanitda Watthanaworawit, Shoklo Malaria Research Unit, Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 68/30 Ban Toong Road, Mae Sot, Tak 63110, Thailand. E-mail:
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25
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Keller CA, Hauptmann M, Kolbaum J, Gharaibeh M, Neumann M, Glatzel M, Fleischer B. Dissemination of Orientia tsutsugamushi and inflammatory responses in a murine model of scrub typhus. PLoS Negl Trop Dis 2014; 8:e3064. [PMID: 25122501 PMCID: PMC4133189 DOI: 10.1371/journal.pntd.0003064] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 06/20/2014] [Indexed: 01/10/2023] Open
Abstract
Central aspects in the pathogenesis of scrub typhus, an infection caused by Orientia (O.) tsutsugamushi, have remained obscure. Its organ and cellular tropism are poorly understood. The purpose of this study was to analyze the kinetics of bacterial dissemination and associated inflammatory responses in infected tissues in an experimental scrub typhus mouse model, following infection with the human pathogenic strain Karp. We provide a thorough analysis of O. tsutsugamushi infection in inbred Balb/c mice using footpad inoculation, which is close to the natural way of infection. By a novel, highly sensitive qPCR targeting the multi copy traD genes, we quantitatively monitored the spread of O. tsutsugamushi Karp from the skin inoculation site via the regional lymph node to the internal target organs. The highest bacterial loads were measured in the lung. Using confocal imaging, we also detected O. tsutsugamushi at the single cell level in the lung and found a predominant macrophage rather than endothelial localization. Immunohistochemical analysis of infiltrates in lung and brain revealed differently composed lesions with specific localizations: iNOS-expressing macrophages were frequent in infiltrative parenchymal noduli, but uncommon in perivascular lesions within these organs. Quantitative analysis of the macrophage response by immunohistochemistry in liver, heart, lung and brain demonstrated an early onset of macrophage activation in the liver. Serum levels of interferon (IFN)-γ were increased during the acute infection, and we showed that IFN-γ contributed to iNOS-dependent bacterial growth control. Our data show that upon inoculation to the skin, O. tsutsugamushi spreads systemically to a large number of organs and gives rise to organ-specific inflammation patterns. The findings suggest an essential role for the lung in the pathogenesis of scrub typhus. The model will allow detailed studies on host-pathogen interaction and provide further insight into the pathogenesis of O. tsutsugamushi infection. Many details of the pathogenesis of scrub typhus, an infection caused by the intracellular bacterium Orientia tsutsugamushi that is endemic in Southeast Asia, have remained unclear until today. In this study, we present an experimental self-healing mouse model of scrub typhus based on footpad skin inoculation of the human pathogenic Karp strain of O. tsutsugamushi that shares many features with human infection. We established a novel quantitative PCR with increased sensitivity for the measurement of bacterial organ loads of infected mice. It was thereby shown that O. tsutsugamushi initially accumulated in the regional lymph node and subsequently spread to many organs with the highest bacterial loads found in the lung. The predominant host cells in the lung were macrophages located in the parenchymal interstitium, rather than endothelial cells. Our data also show unexpected organ-specific differences in the dynamics of macrophage activation. This mouse model will help to advance our understanding of scrub typhus pathogenesis.
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Affiliation(s)
| | | | - Julia Kolbaum
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | - Melanie Neumann
- Mouse Pathology Core Facility, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Bernhard Fleischer
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Institute of Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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27
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Lee KD, Moon C, Oh WS, Sohn KM, Kim BN. Diagnosis of scrub typhus: introduction of the immunochromatographic test in Korea. Korean J Intern Med 2014; 29:253-5. [PMID: 24648812 PMCID: PMC3956999 DOI: 10.3904/kjim.2014.29.2.253] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Revised: 12/30/2013] [Accepted: 12/31/2013] [Indexed: 11/27/2022] Open
Affiliation(s)
- Ki-Deok Lee
- Division of Infectious Diseases, Department of Internal Medicine, Eulji General Hospital, Seoul, Korea
| | - Chisook Moon
- Division of Infectious Diseases, Department of Internal Medicine, Inje University Busan Paik Hospital, Busan, Korea
| | - Won Sup Oh
- Division of Infectious Diseases, Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Kyung Mok Sohn
- Division of Infectious Diseases, Chungnam National University Hospital, Daejeon, Korea
| | - Baek-Nam Kim
- Department of Internal Medicine, Inje University Sanggye Paik Hospital, Seoul, Korea
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28
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Park HS, Lee JH, Jeong EJ, Kim JE, Hong SJ, Park TK, Kim TY, Jang WJ, Park KH, Kim BJ, Kook YH, Lee SH. Rapid and Simple Identification ofOrientia tsutsugamushifrom Other Group Rickettsiae by Duplex PCR Assay UsinggroELGene. Microbiol Immunol 2013; 49:545-9. [PMID: 15965302 DOI: 10.1111/j.1348-0421.2005.tb03760.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, two new duplex PCR methods based on the groEL gene were developed and investigated for the diagnosis of rickettsiae. The first duplex PCR assay amplified the 229-bp and the 366-bp DNAs of 6 strains including typhus group (TG) and spotted fever group (SFG) rickettsiae, and 5 scrub typhus group (STG) rickettsiae, respectively. The second duplex PCR assay amplified the 397-bp and the 213-bp DNAs of 6 Rickettsia strains and 5 STG strains. These duplex PCR methods could simultaneously perform the rapid identification of rickettsiae and the differential diagnosis of STG and other group rickettsiae in a single reaction.
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Affiliation(s)
- Hyo-Soon Park
- Department of Microbiology, Konkuk University, Chungju, Chungchongbuk-Do, Korea
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29
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Affiliation(s)
- Sun hee Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Research Institute of Clinical Medicine of Chonbuk National University, Chonbuk National University Hospital, Chonbuk National University Medical School, 634-18, Keum-Am Dong, Jeonju, 561-712, South Korea
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Li W, Dou X, Zhang L, Lyu Y, Du Z, Tian L, Zhang X, Sun Y, Guan Z, Chen L, Li X, Wang Q. Laboratory diagnosis and genotype identification of scrub typhus from Pinggu district, Beijing, 2008 and 2010. Am J Trop Med Hyg 2013; 89:123-9. [PMID: 23716411 PMCID: PMC3748468 DOI: 10.4269/ajtmh.12-0728] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 04/27/2013] [Indexed: 11/07/2022] Open
Abstract
This study was conducted to determine the diagnosis and genotype of Orientia tsutsugamushi in Pinggu district, Beijing. Indirect immunofluorescence assay (IFA) was performed to detect O. tsutsugamushi-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies. Nested polymerase chain reaction (PCR) and DNA sequencing analysis targeting the O. tsutsugamushi-specific groEL gene and 56 kDa protein gene were performed on whole-blood samples from scrub typhus patients. We confirmed that 47 patients were infected with scrub typhus in Pinggu district, Beijing. Representative sequences amplified by primers according to the groEL gene (BJ-PG-2008; GenBank accession No. JQ894502) and the 56 kDa protein gene (PG-56kDa; GenBank accession No. JX843795) both clustered with Kawasaki. PG-56kDa had sequence homology of 100% with TADY12-0308, shandong-XDM2, Neimeng-90, and sdu-1 and sequence homology of 96% with Kawasaki, Taguchi, Oishi, and Kanda. We confirmed the genotype of O. tsutsugamushi in Pinggu district, Beijing, as Kawasaki, and the patient in 2008 confirmed in this study was the first patient with confirmed scrub typhus in Beijing.
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Affiliation(s)
- Weihong Li
- Beijing Center for Disease Prevention and Control, Beijing, People's Republic of China.
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Jiang J, Paris DH, Blacksell SD, Aukkanit N, Newton PN, Phetsouvanh R, Izzard L, Stenos J, Graves SR, Day NPJ, Richards AL. Diversity of the 47-kD HtrA nucleic acid and translated amino acid sequences from 17 recent human isolates of Orientia. Vector Borne Zoonotic Dis 2013; 13:367-75. [PMID: 23590326 DOI: 10.1089/vbz.2012.1112] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Orientia tsutsugamushi, the etiologic agent of potentially fatal scrub typhus, is characterized by a high antigenic diversity, which complicates the development of a broadly protective vaccine. Efficacy studies in murine and nonhuman primate models demonstrated the DNA vaccine candidate pKarp47, based upon the O. tsutsugamushi Karp 47-kD HtrA protein gene, to be a successful immunoprophylactic against scrub typhus. To characterize 47-kD HtrA protein diversity among human isolates of Orientia, we sequenced the full open reading frame (ORF) of the 47-kD HtrA gene and analyzed the translated amino acid sequences of 17 patient isolates from Thailand (n=13), Laos (n=2), Australia (n=1), and the United Arab Emirates (UAE) (n=1) and 9 reference strains: Karp (New Guinea), Kato (Japan), Ikeda (Japan), Gilliam (Burma), Boryong (Korea), TA763, TH1811 and TH1817 (Thailand), and MAK243 (China). The percentage identity (similarity) of translated amino acid sequences between 16 new isolates and 9 reference strains of O. tsutsugamushi ranged from 96.4% to 100% (97.4% to 100%). However, inclusion of the recently identified Orientia chuto sp. nov. reduced identity (similarity) values to 82.2% to 83.3% (90.4% to 91.4%). These results demonstrate the diversity of Orientia 47-kD HtrA among isolates encountered by humans and therefore provide support for the necessity of developing a broadly protective scrub typhus vaccine that takes this diversity into account.
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Affiliation(s)
- Ju Jiang
- Naval Medical Research Center , Silver Spring, Maryland, USA
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Phetsouvanh R, Thojaikong T, Phoumin P, Sibounheuang B, Phommasone K, Chansamouth V, Lee SJ, Newton PN, Blacksell SD. Inter- and intra-operator variability in the reading of indirect immunofluorescence assays for the serological diagnosis of scrub typhus and murine typhus. Am J Trop Med Hyg 2013; 88:932-936. [PMID: 23478577 PMCID: PMC3752761 DOI: 10.4269/ajtmh.12-0325] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Inter- and intra-observer variation was examined among six microscopists who read 50 scrub typhus (ST) and murine typhus (MT) indirect immunofluorescence assay (IFA) immunoglobulin M (IgM) slides. Inter-observer agreement was moderate (κ = 0.45) for MT and fair (κ = 0.32) for ST, and was significantly correlated with experience (P = 0.03 and P = 0.004, respectively); κ-scores for intra-observer agreement between morning and afternoon readings (range = 0.35–0.86) were not correlated between years of experience for ST and MT IFAs (Spearman's ρ = 0.31, P = 0.54 and P = 0.14, respectively; P = 0.78). Storage at 4°C for 2 days showed a change from positive to negative in 20–32% of slides. Although the titers did not dramatically change after 14 days of storage, the final interpretation (positive to negative) did change in 36–50% of samples, and it, therefore, recommended that slides should be read as soon as possible after processing.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Stuart D. Blacksell
- *Address correspondence to Stuart D. Blacksell, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Rd., Bangkok 10400, Thailand. E-mail:
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Cho BA, Ko Y, Kim YS, Kim S, Choi MS, Kim IS, Kim HR, Cho NH. Phenotypic characterization of peripheral T cells and their dynamics in scrub typhus patients. PLoS Negl Trop Dis 2012; 6:e1789. [PMID: 22905277 PMCID: PMC3419201 DOI: 10.1371/journal.pntd.0001789] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 07/10/2012] [Indexed: 11/26/2022] Open
Abstract
Background Scrub typhus, caused by Orientia tsutsugamushi infection, is one of the main causes of febrile illness in the Asia-Pacific region. Although cell-mediated immunity plays an important role in protection, little is known about the phenotypic changes and dynamics of leukocytes in scrub typhus patients. Methodology/Principal Findings To reveal the underlying mechanisms of immunological pathogenesis, we extensively analyzed peripheral blood leukocytes, especially T cells, during acute and convalescent phases of infection in human patients and compared with healthy volunteers. We observed neutrophilia and CD4+ T lymphopenia in the acute phase of infection, followed by proliferation of CD8+ T cells during the convalescent phase. Massive T cell apoptosis was detected in the acute phase and preferential increase of CD8+ T cells with activated phenotypes was observed in both acute and convalescent phases, which might be associated or correlated with elevated serum IL-7 and IL-15. Interestingly, peripheral Treg cells were significantly down-regulated throughout the disease course. Conclusions/Significance The remarkable decrease of CD4+ T cells, including Treg cells, during the acute phase of infection may contribute to the loss of immunological memory that are often observed in vaccine studies and recurrent human infection. Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi infection. It has been estimated that one billion people are at risk and one million new cases arise each year in Asian-pacific region. Despite of aggressive attempts to develop a prophylactic vaccine against scrub typhus during the last several decades, all approaches have failed to generate long lasting immunity. In addition, little is known about the immunological pathogenesis of scrub typhus. To understand the pathogenic mechanisms of this infectious disease, we extensively analyzed peripheral leukocytes, especially T cells, in Korean scrub typhus patients and compared with healthy volunteers. We observed neutrophilia and CD4+/T lymphopenia in the acute phase of infection, followed by proliferation of CD8+ T cells during the convalescent phase. Massive T cell apoptosis was detected in the acute phase and a preferential increase of CD8+ T cells with activated phenotypes was observed in both acute and convalescent phases. The remarkable decrease of CD4+ T cells, including Treg cells, during the acute phase of infection may contribute to the loss of immunological memory and generate helpless but unregulated cytotoxic T cell responses observed in vaccine studies and recurrent human infection.
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Affiliation(s)
- Bon-A Cho
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Anatomy, Seoul National University College of Medicine, Seoul, Republic of Korea
- Institute of Endemic Disease, Seoul National University Medical Research Center, Seoul, Republic of Korea
| | - Youngho Ko
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Yeon-Sook Kim
- Divisions of Infectious Diseases, Chungnam National University Hospital, Daejeon, Republic of Korea
| | - Sanguk Kim
- Department of Life Science and School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Kyungbuk, 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
| | - Hang-Rae Kim
- Department of Anatomy, Seoul National University College of Medicine, Seoul, Republic of Korea
- * E-mail: (NHC); (HRK)
| | - Nam-Hyuk Cho
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Institute of Endemic Disease, Seoul National University Medical Research Center, Seoul, Republic of Korea
- Bundang Hospital, Seoul, Republic of Korea
- * E-mail: (NHC); (HRK)
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Prachason T, Konhan K, Pongnarin P, Chatsiricharoenkul S, Suputtamongkol Y, Limwongse C. Activation of indoleamine 2,3-dioxygenase in patients with scrub typhus and its role in growth restriction of Orientia tsutsugamushi. PLoS Negl Trop Dis 2012; 6:e1731. [PMID: 22860140 PMCID: PMC3409113 DOI: 10.1371/journal.pntd.0001731] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 06/01/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Our earlier genome-wide expression study revealed up-regulation of a tryptophan-catabolizing enzyme, indoleamine 2,3-dioxygenase (IDO1), in patients with scrub typhus. This gene has been previously reported to have anti-microbial activity in a variety of infectious diseases; therefore, we aimed to prove whether it is also involved in host defense against Orientia tsutsugamushi (OT) infection. METHODOLOGY/PRINCIPAL FINDINGS Using LC-MS, we observed an increased ratio of serum L-kynurenine to serum L-tryptophan in patients with scrub typhus, which suggests an active catalytic function of this enzyme upon the illness. To evaluate the effect of IDO1 activation on OT infection, a human macrophage-like cell line THP-1 was used as a study model. Although transcription of IDO1 was induced by OT infection, its functional activity was not significantly enhanced unless the cells were pretreated with IFN-γ, a potent inducer of IDO1. When the degree of infection was evaluated by quantitative real-time PCR, the relative number of OT 47 kDa gene per host genes, or infection index, was markedly reduced by IFN-γ treatment as compared to the untreated cultures at five days post-infection. Inhibition of IDO1 activity in IFN-γ treated cultures by 1-methyl-L-tryptophan, a competitive inhibitor of IDO1, resulted in partial restoration of infection index; while excessive supplementation of L-tryptophan in IFN-γ treated cultures raised the index to an even higher level than that of the untreated ones. Altogether, these data implied that IDO1 was partly involved in restriction of OT growth caused by IFN-γ through deprivation of tryptophan. CONCLUSIONS/SIGNIFICANCE Activation of IDO1 appeared to be a defensive mechanism downstream of IFN-γ that limited intracellular expansion of OT via tryptophan depletion. Our work provided not only the first link of in vivo activation of IDO1 and IFN-γ-mediated protection against OT infection but also highlighted the promise of this multifaceted gene in scrub typhus research.
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Affiliation(s)
- Thanavadee Prachason
- Division of Molecular Genetics, Department of Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Department of Immunology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Kanittha Konhan
- Department of Pharmacology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Piyapat Pongnarin
- Department of Pharmacology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | | | - Yupin Suputtamongkol
- Division of Infectious Diseases, Department of Internal Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Chanin Limwongse
- Division of Molecular Genetics, Department of Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Division of Medical Genetics, Department of Internal Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
- * E-mail:
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Koo JE, Hong HJ, Dearth A, Kobayashi KS, Koh YS. Intracellular invasion of Orientia tsutsugamushi activates inflammasome in asc-dependent manner. PLoS One 2012; 7:e39042. [PMID: 22723924 PMCID: PMC3377614 DOI: 10.1371/journal.pone.0039042] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Accepted: 05/15/2012] [Indexed: 12/31/2022] Open
Abstract
Orientia tsutsugamushi, a causative agent of scrub typhus, is an obligate intracellular bacterium, which escapes from the endo/phagosome and replicates in the host cytoplasm. O. tsutsugamushi infection induces production of pro-inflammatory mediators including interleukin-1β (IL-1β), which is secreted mainly from macrophages upon cytosolic stimuli by activating cysteine protease caspase-1 within a complex called the inflammasome, and is a key player in initiating and maintaining the inflammatory response. However, the mechanism for IL-1β maturation upon O. tsutsugamushi infection has not been identified. In this study, we show that IL-1 receptor signaling is required for efficient host protection from O. tsutsugamushi infection. Live Orientia, but not heat- or UV-inactivated Orientia, activates the inflammasome through active bacterial uptake and endo/phagosomal maturation. Furthermore, Orientia-stimulated secretion of IL-1β and activation of caspase-1 are ASC- and caspase-1- dependent since IL-1β production was impaired in Asc- and caspase-1-deficient macrophages but not in Nlrp3-, Nlrc4- and Aim2-deficient macrophages. Therefore, live O. tsutsugamushi triggers ASC inflammasome activation leading to IL-1β production, which is a critical innate immune response for effective host defense.
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Affiliation(s)
- Jung-Eun Koo
- Department of Microbiology and Immunology, Brain Korea 21 Program, Jeju National University School of Medicine, Jeju, Jeju-Do, South Korea
- Institute of Medical Science, Jeju National University, Jeju, Jeju-Do, South Korea
| | - Hye-Jin Hong
- Department of Microbiology and Immunology, Brain Korea 21 Program, Jeju National University School of Medicine, Jeju, Jeju-Do, South Korea
- Institute of Medical Science, Jeju National University, Jeju, Jeju-Do, South Korea
| | - Andrea Dearth
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Koichi S. Kobayashi
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (YSK); (KK)
| | - Young-Sang Koh
- Department of Microbiology and Immunology, Brain Korea 21 Program, Jeju National University School of Medicine, Jeju, Jeju-Do, South Korea
- Institute of Medical Science, Jeju National University, Jeju, Jeju-Do, South Korea
- * E-mail: (YSK); (KK)
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Zhang L, He S, Wang S, Yu H, Li X, Zhang D, Pan L, Yu Q. Comparison of a rapid diagnostic test and microimmunofluorescence assay for detecting antibody to Orientia tsutsugamushi in scrub typhus patients in China. ASIAN PAC J TROP MED 2012; 4:666-8. [PMID: 21914549 DOI: 10.1016/s1995-7645(11)60169-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 06/11/2011] [Accepted: 07/15/2011] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE To evaluate the detection of IgM and IgG antibodies to Orientia tsutsugamushi (O. tsutsugamushi) by rapid diagnostic test (RDT) and microimmunofluorescence assay (mIFA). METHODS RDT using a mixture of recombinant 56-kDa proteins of O. tsutsugamushi and mIFA assay were performed on 20 patients from Fujian and 13 patients from Yunnan Province, and 82 sera samples from healthy farmers in Anhui Province and Beijing City in 2009. Comparison of the RDT and mIFA assay was performed by using X(2) test and the P level of <0.05 was considered to be significance. RESULTS Among these 82 normal sera samples, the specificity of RDT was 100% for both IgM and IgG tests. In 33 samples from patients with scrub typhus, 5 cases were positively detected earlier by RDT than by mIFA in IgM test, and 2 cases were positive in IgG test. Sensitivities of RDT were 93.9% and 90.9% for IgM and IgG, respectively. The sensitivity of combination test of IgM and IgG was 100%. Geometric mean titer diluted sera from confirmed cases by IFA and RDT assay were 1:37 vs. 1:113 (P<0.001) in IgM test and 1:99 vs. 1:279 (P<0.05) in IgG test. CONCLUSIONS RDT is more sensitivite than mIFA in the early diagnosis of scrub typhus and it is particularly applicable in rural areas.
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Affiliation(s)
- Lijuan Zhang
- Department of Rickettsiology, National Institute of Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China.
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Kuo CC, Huang CL, Wang HC. Identification of potential hosts and vectors of scrub typhus and tick-borne spotted fever group rickettsiae in eastern Taiwan. Med Vet Entomol 2011; 25:169-177. [PMID: 21223345 DOI: 10.1111/j.1365-2915.2010.00941.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Scrub typhus and tick-borne spotted fever group (SFG) rickettsioses are transmitted by chiggers (larval trombiculid mites) and hard ticks, respectively. We assessed exposure to these disease vectors by extensively sampling both chiggers and ticks and their small mammal hosts in eastern Taiwan during 2007 and 2008. The striped field mouse Apodemus agrarius Pallas (Rodentia: Muridae) was the most common of the small mammals (36.1% of 1393 captures) and presented the highest rate of infestation with both chiggers (47.8% of 110 760) and ticks (78.1% of 1431). Leptotrombidium imphalum Vercammen-Grandjean & Langston (Trombidiformes: Trombiculidae) and immature Rhipicephalus haemaphysaloides Supino (Ixodida: Ixodidae) were the most abundant chiggers (84.5%) and ticks (>99%) identified, respectively. Immunofluorescent antibody assay revealed high seropositive rates of rodents against Orientia tsutsugamushi Hyashi (Rickettsiales: Rickettsiaceae), the aetiological agent of scrub typhus (70.0% of 437 rodents), and tick-borne SFG rickettsiae (91.9% of 418 rodents). The current study represents a first step towards elucidating the potential hosts and vectors in the enzootic transmission of O. tsutsugamushi and tick-borne SFG rickettsiae in Taiwan. Further studies should focus on characterizing pathogens in L. imphalum and R. haemaphysaloides, as well as the proclivity of both vectors to humans. Uncovering the main hosts of adult ticks is also critical for the prevention of SFG rickettsial infections.
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Affiliation(s)
- C C Kuo
- Research and Diagnostic Centre, Centres for Disease Control, Taipei, Taiwan, R.O.C
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Tantibhedhyangkul W, Prachason T, Waywa D, El Filali A, Ghigo E, Thongnoppakhun W, Raoult D, Suputtamongkol Y, Capo C, Limwongse C, Mege JL. Orientia tsutsugamushi stimulates an original gene expression program in monocytes: relationship with gene expression in patients with scrub typhus. PLoS Negl Trop Dis 2011; 5:e1028. [PMID: 21610853 PMCID: PMC3096591 DOI: 10.1371/journal.pntd.0001028] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 02/22/2011] [Indexed: 12/14/2022] Open
Abstract
Orientia tsutsugamushi is the causal agent of scrub typhus, a public health problem in the Asia-Pacific region and a life-threatening disease. O. tsutsugamushi is an obligate intracellular bacterium that mainly infects endothelial cells. We demonstrated here that O. tsutsugamushi also replicated in monocytes isolated from healthy donors. In addition, O. tsutsugamushi altered the expression of more than 4,500 genes, as demonstrated by microarray analysis. The expression of type I interferon, interferon-stimulated genes and genes associated with the M1 polarization of macrophages was significantly upregulated. O. tsutsugamushi also induced the expression of apoptosis-related genes and promoted cell death in a small percentage of monocytes. Live organisms were indispensable to the type I interferon response and apoptosis and enhanced the expression of M1-associated cytokines. These data were related to the transcriptional changes detected in mononuclear cells isolated from patients with scrub typhus. Here, the microarray analyses revealed the upregulation of 613 genes, which included interferon-related genes, and some features of M1 polarization were observed in these patients, similar to what was observed in O. tsutsugamushi-stimulated monocytes in vitro. This is the first report demonstrating that monocytes are clearly polarized in vitro and ex vivo following exposure to O. tsutsugamushi. These results would improve our understanding of the pathogenesis of scrub typhus, during which interferon-mediated activation of monocytes and their subsequent polarization into an M1 phenotype appear critical. This study may give us a clue of new tools for the diagnosis of patients with scrub typhus.
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Affiliation(s)
- Wiwit Tantibhedhyangkul
- Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, Centre National de la Recherche Scientifique - Institut de Recherche pour le Développement Unité Mixte de Recherche 6236, Université de la Méditerranée, Faculté de Médecine, Marseille, France
- Department of Immunology, Mahidol University, Bangkok, Thailand
| | - Thanavadee Prachason
- Division of Molecular Genetics, Department of Research and Development, Mahidol University, Bangkok, Thailand
- Department of Immunology, Mahidol University, Bangkok, Thailand
| | - Duangdao Waywa
- Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Adil El Filali
- Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, Centre National de la Recherche Scientifique - Institut de Recherche pour le Développement Unité Mixte de Recherche 6236, Université de la Méditerranée, Faculté de Médecine, Marseille, France
| | - Eric Ghigo
- Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, Centre National de la Recherche Scientifique - Institut de Recherche pour le Développement Unité Mixte de Recherche 6236, Université de la Méditerranée, Faculté de Médecine, Marseille, France
| | - Wanna Thongnoppakhun
- Division of Molecular Genetics, Department of Research and Development, Mahidol University, Bangkok, Thailand
| | - Didier Raoult
- Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, Centre National de la Recherche Scientifique - Institut de Recherche pour le Développement Unité Mixte de Recherche 6236, Université de la Méditerranée, Faculté de Médecine, Marseille, France
| | - Yupin Suputtamongkol
- Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Christian Capo
- Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, Centre National de la Recherche Scientifique - Institut de Recherche pour le Développement Unité Mixte de Recherche 6236, Université de la Méditerranée, Faculté de Médecine, Marseille, France
| | - Chanin Limwongse
- Division of Molecular Genetics, Department of Research and Development, Mahidol University, Bangkok, Thailand
- Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Jean-Louis Mege
- Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, Centre National de la Recherche Scientifique - Institut de Recherche pour le Développement Unité Mixte de Recherche 6236, Université de la Méditerranée, Faculté de Médecine, Marseille, France
- * E-mail:
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Chung DR, Lee YS, Lee SS. Kinetics of inflammatory cytokines in patients with scrub typhus receiving doxycycline treatment. J Infect 2007; 56:44-50. [PMID: 17976731 DOI: 10.1016/j.jinf.2007.09.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2007] [Revised: 09/18/2007] [Accepted: 09/19/2007] [Indexed: 11/17/2022]
Abstract
OBJECTIVES Animal models have suggested that various cytokines and chemokines play an important role in host defense against Orientia tsutsugamushi, however, human data are limited. We investigated the kinetics of inflammatory responses in patients with scrub typhus receiving doxycycline. METHODS Amongst patients being treated for scrub typhus, serially collected sera were tested for TNF-alpha, IFN-gamma, IL-2, IL-4, IL-5, and IL-10 by immunoassay. The mRNAs encoding TNF-alpha, IL-1 beta, IL-6, IL-8, IFN-gamma, IL-12, IL-2, IL-4, IL-5, and IL-10 were measured by semiquantitative reverse transcription-PCR. RESULTS The concentrations of TNF-alpha, IFN-gamma, and IL-10 of patients prior to doxycycline treatment were significantly higher than those of healthy volunteers. They decreased markedly within 24h after starting doxycycline. The mRNAs for IL-1 beta, TNF-alpha, IL-6, IFN-gamma, and IL-10 were highly expressed. Expression of mRNAs for IL-1 beta, IFN-gamma, and IL-10 decreased at day 2-7 of doxycycline treatment. CONCLUSIONS Inflammatory cytokines including TNF-alpha, IL-1 beta, and IL-6 are markedly upregulated in patients with scrub typhus. Doxycycline treatment rapidly reduces the production of these cytokines, corresponding to the early defervescence after the start of the treatment. The profiles of T cell-derived cytokines in patients with scrub typhus do not follow typical Th1 or Th2 patterns.
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Affiliation(s)
- Doo Ryeon Chung
- Division of Infectious Diseases, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, 896 Pyeongchon-dong, Dongan-gu, Anyang-si, Gyeonggi-do 431-070, South Korea.
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Jones ML, Barnard RT. Use of chimeric antibodies as positive controls in an enzyme-linked immunosorbent assay for diagnosis of scrub typhus (infection by Orientia tsutsugamushi). Clin Vaccine Immunol 2007; 14:1307-10. [PMID: 17687111 PMCID: PMC2168107 DOI: 10.1128/cvi.00114-07] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The use of human sera collected from individuals of known infected and noninfected status is necessary for the validation of diagnostic assays and for the determination of cutoff values. However, the routine inclusion of pooled human sera from infected individuals for use as positive controls in commercial assay kits has many disadvantages. Sufficient quantities of sera can be difficult to obtain, and there are ethical and safety issues to be considered. Additionally, each batch of control material requires standardization, as each will differ in antibody titer. We have genetically engineered chimeric immunoglobulin G (IgG), IgM, and IgA antibodies consisting of mouse-derived variable regions and human constant regions derived from peripheral blood lymphocytes. The chimeric nature of these antibodies allows the desired antigen specificity created through mouse immunization and hybridoma technology while retaining a human constant region required for recognition by the enzyme-conjugated antihuman signal antibody. We have investigated the potential use of chimeric IgG with specificity for the major surface antigen of Orientia tsutsugamushi as an alternative positive control for inclusion in a commercial enzyme-linked immunosorbent assay kit for the diagnosis of rickettsia scrub typhus (caused by infection with O. tsutsugamushi). Chimeric IgG was expressed in stably transfected CHO cells, allowing production of unlimited quantities. The purified protein was found to have a much greater specificity for the scrub typhus antigen than the serum-derived controls. The methods described could be applied to other assay kits for the detection of antibodies against infectious agents.
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Affiliation(s)
- Martina L Jones
- School of Molecular and Microbial Sciences, University of Queensland, St. Lucia 4072, QLD, Australia.
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Abstract
Scrub typhus, an acute, febrile and potentially fatal disease, caused by infection with the obligate intracellular bacterium Orientia tsutsugamushi, is commonly seen in the Asia-Pacific region. This disease can be handled successfully with rapid diagnosis, proper antibiotic treatment, and rodent and chigger control. However, recent reports of scrub typhus outbreaks in endemic areas, and a decreased effectiveness of antibiotic treatment suggest a continued need for a suitable vaccine. This review describes the early and recent attempts in making prophylactic preparations to prevent scrub typhus, the successes and failures of these attempts, and future directions of scrub typhus vaccine development.
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Affiliation(s)
- Suchismita Chattopadhyay
- Rickettsial Diseases Research Program, Naval Medical Research Center, Silver Spring, Maryland 20910, USA.
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Abstract
Himachal Pradesh state of India is situated in the outer Himalayan ranges. During the rainy season, several cases of acute febrile illness of unknown origin occurred. Orientia tsutsugamushi was identified as the causative agent by microimmunofluorescence and PCR. Two new genotypes of O. tsutsugamushi were identified in the region.
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Lerdthusnee K, Jenkitkasemwong S, Insuan S, Leepitakrat W, Monkanna T, Khlaimanee N, Chareonsongsermkij W, Leepitakrat S, Chayaphum K, Jones JW. Comparison of immune response against Orientia tsutsugamushi, a causative agent of scrub typhus, in 4-week-old and 10-week-old scrub typhus-infected laboratory mice using enzyme-linked immunosorbent assay technique. Ann N Y Acad Sci 2007; 1078:607-12. [PMID: 17114788 DOI: 10.1196/annals.1374.121] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Using the indirect enzyme-linked immunosorbent assay (ELISA) technique, we compared the immune response of specific antibodies (IgM and IgG) in serum samples of scrub typhus-infected and non-infected mice against Orientia sutsugamushi (a causative agent of scrub typhus). Two different age groups (4-week-old and 10-week-old) of ICR laboratory mice were infected with O. tsutsugamushi by the animal passage procedure. Serum samples were detected for scrub typhus-specific antibodies using ELISA technique. Results from determining the presence of IgM and IgG in the serum samples obtained from scrub typhus-infected mice showed that the IgG was first detected on day-13 after the initial infection in both the 4-week-old and 10-week-old mice. The IgG titer levels of both groups were not significantly different. Although the presence of IgM in the in serum samples obtained from scrub typhus-infected mice was first detected on day 13 in the 4-week-old mice and on day-12 in the 10-week-old mice, the IgM titer in the 4-week-old mice was slightly lower than in the 10-week-old mice. Clinical observations of the scrub typhus-infected mice showed that the older mice become ill on day 9 whereas the younger mice exhibited the symptoms on day 12. Considering the earlier detection and slightly higher level of specific IgM antibody, it could be interpreted that the older mice may appear to have responded against O. tsutsugamushi faster than the younger mice.
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Affiliation(s)
- Kriangkrai Lerdthusnee
- Department of Entomology, USAMC-AFRIMS, 315/6 Rajvithi Road, Phya Thai, Bangkok 10400, Thailand.
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Abstract
Many microbial pathogens have epitopes shared with host cell components and these epitopes may induce transient or longer-term tissue-damaging autoantibody responses. We observed that several mouse monoclonal antibodies (MAbs) raised against Orientia tsutsugamushi were also reactive with host cells. One such antibody, MAb Rb105, cross-reacted with the cytoskeleton, as shown by immunofluorescent staining. Biochemical studies identified the cross-reacting component as a cytokeratin protein. These results identify an epitope shared by O. tsutsugamushi and the cytokeratins of host cells. In addition, antibodies cross-reactive with the cytoskeleton were detected in the sera of scrub typhus patients, suggesting that an epitope similar to that detected by MAb Rb105 may be recognized by human antibodies.
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Affiliation(s)
- Mi-Jeong Kim
- Department of Microbiology and Research Institute for Medical Science, Inha University College of Medicine, Jungsuk B/D, 3rd Street, Shinheung-Dong, Choong-Gu, Incheon 400-712, Republic of Korea
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Xu G, Chattopadhyay S, Jiang J, Chan TC, Chao CC, Ching WM, Richards AL. Short- and long-term immune responses of CD-1 outbred mice to the scrub typhus DNA vaccine candidate: p47Kp. Ann N Y Acad Sci 2006; 1063:266-9. [PMID: 16481526 DOI: 10.1196/annals.1355.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Orientia tsutsugamushi is an obligate intracellular bacterium that is the causative agent of scrub typhus. To develop an effective vaccine to prevent or ameliorate scrub typhus, knowledge of the protective immune response to O. tsutsugamushi needs to be ascertained. Our laboratory has demonstrated that the DNA vaccine vector pVR1012 carrying the O. tsutsugamushi Karp strain 47-kDa protein gene (p47Kp) consistently provides outbred mice protection against homologous challenge.
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Affiliation(s)
- Guang Xu
- Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910-7500, USA
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Ni YS, Chan TC, Chao CC, Richards AL, Dasch GA, Ching WM. Protection against scrub typhus by a plasmid vaccine encoding the 56-KD outer membrane protein antigen gene. Am J Trop Med Hyg 2005; 73:936-41. [PMID: 16282307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
The 56-kD outer membrane protein of Orientia tsutsugamushi has previously been shown to be the immunodominant antigen in scrub typhus infections. Its gene was cloned into the DNA vaccine vector pVR1012 as a vaccine candidate (pKarp56). The in vitro expression of this 56-kD antigen by pKarp56 was confirmed in tissue culture by an indirect fluorescence assay and Western blot analysis. The initial antibody responses of mice immunized with varied doses of the pKarp56 were barely detected, but increases were observed after each of three subsequent booster immunizations. Although no protection was observed with a single immunization of pKarp56, after four immunizations, 60% of the mice survived a 1,000 x 50% lethal dose (LD(50)) challenge. These results specifically confirm the importance of the 56-kD protein antigen in protective immunity against O. tsutsugamushi and demonstrate the feasibility of DNA vaccines for the prevention of scrub typhus.
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Affiliation(s)
- Yi-Sheng Ni
- Rickettsial Diseases Department, U.S. Naval Medical Research Center, Silver Spring, Maryland 20910, USA
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Yun JH, Koh YS, Lee KH, Hyun JW, Choi YJ, Jang WJ, Park KH, Cho NH, Seong SY, Choi MS, Kim IS. Chemokine and cytokine production in susceptible C3H/HeN mice and resistant BALB/c mice during Orientia tsutsugamushi infection. Microbiol Immunol 2005; 49:551-7. [PMID: 15965303 DOI: 10.1111/j.1348-0421.2005.tb03761.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
To understand the pathogenesis of scrub typhus, we examined chemokine and cytokine production in susceptible (C3H/HeN) and resistant (BALB/c) mice after infection with O. tsutsugamushi Gilliam. C3H/HeN mice produced high levels of chemokines macrophage inflammatory proteins 1 alpha (MIP-1 alpha ), MIP-2, monocyte chemoattractant protein 1 (MCP-1), and cytokines gamma-interferon (IFN-gamma ), interleukin-12 (IL-12), IL-10, and tumor necrosis factor alpha (TNF-alpha ) in response to O. tsutsugamushi infection, compared to BALB/c mice. Chemokine profiles in infected mice correlated well with the kinetics of inflammatory cell infiltration. Hyperproduction of chemokines and cytokines was observed in another susceptible-infection model (BALB/c-Karp). These results suggest that hyperproduction of chemokines and cytokines are associated with susceptibility during O. tsutsugamushi infection.
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Affiliation(s)
- Ji-Hyun Yun
- Department of Microbiology, Cheju National University College of Medicine, Jeju, Republic of Korea
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Fukuhara M, Fukazawa M, Tamura A, Nakamura T, Urakami H. Survival of two Orientia tsutsugamushi bacterial strains that infect mouse macrophages with varying degrees of virulence. Microb Pathog 2005; 39:177-87. [PMID: 16165341 DOI: 10.1016/j.micpath.2005.08.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2005] [Revised: 08/02/2005] [Accepted: 08/05/2005] [Indexed: 11/23/2022]
Abstract
Orientia tsutsugamushi, an intracellular parasitic bacterium, comprises numerous strains of differing virulence. When BALB/c mice were infected intraperitoneally with this pathogen, a virulent strain known as Karp was found to multiply in the intraperitoneal macrophages and kill the mouse. In contrast, an avirulent strain, Kuroki, was shown to invade macrophages but be eliminated from the cells, allowing mouse survival. O. tsutsugamushi invades its host cell cytoplasm through phagocytosis and disruption of phagosomal membranes but some bacteria are then killed by phago-lysosomes within 1h of infection. Microscopic observations could not differentiate the Karp and Kuroki strains during entry and subsequent cell killing by phago-lysosomes. However, the Kuroki cells failed to divide and were markedly deformed following cytoplasmic invasion at several days post-infection. These findings suggest that macrophages have a mechanism to eliminate O. tsutsugamushi in the cytoplasm, if the invading bacteria escape phagosomal clearance, and that it is this mechanism that Kuroki does not survive. Additionally, significant levels of nitric oxide (NO) are produced in macrophages by Kuroki, but not by Karp. An NO synthase inhibitor, however, does not increase the growth of Kuroki, suggesting that NO is induced in a strain-dependent manner but does not effect proliferation.
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Affiliation(s)
- Masahiro Fukuhara
- Laboratory of Microbiology, Faculty of Pharmacy, Niigata University of Pharmacy and Applied Life Sciences (NUPALS), 265-1 Higashijima, Niigata 956-8603, Japan
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Chattopadhyay S, Jiang J, Chan TC, Manetz TS, Chao CC, Ching WM, Richards AL. Scrub typhus vaccine candidate Kp r56 induces humoral and cellular immune responses in cynomolgus monkeys. Infect Immun 2005; 73:5039-47. [PMID: 16041019 PMCID: PMC1201273 DOI: 10.1128/iai.73.8.5039-5047.2005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A truncated recombinant 56-kDa outer membrane protein of the Karp strain of Orientia tsutsugamushi (Kp r56) was evaluated in cynomolgus monkeys (Macaca fascicularis) for immunogenicity and safety as a vaccine candidate for the prevention of scrub typhus. This recombinant antigen induced strong humoral and cellular immune responses in two monkeys and was found to be well tolerated. Antigen-specific immunoglobulin M (IgM) and IgG were produced to almost maximal levels within 1 week of a single immunization. Peripheral blood mononuclear cells from vaccinated animals showed an induction of antigen-specific proliferation and gamma interferon production. The Kp r56 was not as efficient as infection with live organisms in preventing reinfection but was able to reduce the inflammation produced at the site of challenge. This report describes the results of the first systematic study of the immunogenicity of a recombinant scrub typhus vaccine candidate in a nonhuman primate model.
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Affiliation(s)
- Suchismita Chattopadhyay
- Rickettsial Diseases Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
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de Fost M, Chierakul W, Pimda K, Dondorp AM, White NJ, Van der Poll T. Activation of cytotoxic lymphocytes in patients with scrub typhus. Am J Trop Med Hyg 2005; 72:465-7. [PMID: 15827287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
Thai patients with scrub typhus caused by the intracellular pathogen Orientia tsutsugamushi displayed elevated plasma concentrations of granzymes A and B, interferon-gamma (IFN)-gamma-inducible protein 10, and monokine induced by IFN-gamma. These data suggest that activation of cytotoxic lymphocytes is part of the early host response to scrub typhus.
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Affiliation(s)
- Maaike de Fost
- Laboratory of Experimental Internal Medicine and Department of Infectious Diseases, Tropical Medicine and AIDS, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
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