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Liang Y, Wang H, Sun K, Sun J, Soong L. Lack of the IFN-γ signal leads to lethal Orientia tsutsugamushi infection in mice with skin eschar lesions. PLoS Pathog 2024; 20:e1012020. [PMID: 38743761 PMCID: PMC11125519 DOI: 10.1371/journal.ppat.1012020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 05/24/2024] [Accepted: 04/30/2024] [Indexed: 05/16/2024] Open
Abstract
Scrub typhus is an acute febrile disease due to Orientia tsutsugamushi (Ot) infection and can be life-threatening with organ failure, hemorrhage, and fatality. Yet, little is known as to how the host reacts to Ot bacteria at early stages of infection; no reports have addressed the functional roles of type I versus type II interferon (IFN) responses in scrub typhus. In this study, we used comprehensive intradermal (i.d.) inoculation models and two clinically predominant Ot strains (Karp and Gilliam) to uncover early immune events. Karp infection induced sequential expression of Ifnb and Ifng in inflamed skin and draining lymph nodes at days 1 and 3 post-infection. Using double Ifnar1-/-Ifngr1-/- and Stat1-/- mice, we found that deficiency in IFN/STAT1 signaling resulted in lethal infection with profound pathology and skin eschar lesions, which resembled to human scrub typhus. Further analyses demonstrated that deficiency in IFN-γ, but not IFN-I, resulted in impaired NK cell and macrophage activation and uncontrolled bacterial growth and dissemination, leading to metabolic dysregulation, excessive inflammatory cell infiltration, and exacerbated tissue damage. NK cells were found to be the major cellular source of innate IFN-γ, contributing to the initial Ot control in the draining lymph nodes. In vitro studies with dendritic cell cultures revealed a superior antibacterial effect offered by IFN-γ than IFN-β. Comparative in vivo studies with Karp- and Gilliam-infection revealed a crucial role of IFN-γ signaling in protection against progression of eschar lesions and Ot infection lethality. Additionally, our i.d. mouse models of lethal infection with eschar lesions are promising tools for immunological study and vaccine development for scrub typhus.
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Affiliation(s)
- Yuejin Liang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Hui Wang
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Keer Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
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Bao T, Liu X, Hu J, Ma M, Li J, Cao L, Yu B, Cheng H, Zhao S, Tian Z. Recruitment of PVT1 Enhances YTHDC1-Mediated m6A Modification of IL-33 in Hyperoxia-Induced Lung Injury During Bronchopulmonary Dysplasia. Inflammation 2024; 47:469-482. [PMID: 37917328 PMCID: PMC11074042 DOI: 10.1007/s10753-023-01923-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/26/2023] [Accepted: 10/17/2023] [Indexed: 11/04/2023]
Abstract
Bronchopulmonary dysplasia (BPD) is a chronic lung disease that specifically affects preterm infants. Oxygen therapy administered to treat BPD can lead to hyperoxia-induced lung injury, characterized by apoptosis of lung alveolar epithelial cells. Our epitranscriptomic microarray analysis of normal mice lungs and hyperoxia-stimulated mice lungs revealed elevated RNA expression levels of IL-33, as well as increased m6A RNA methylation levels of IL-33 and PVT1 in the hyperoxia-stimulated lungs. This study aimed to investigate the role of the PVT1/IL-33 axis in BPD. A mouse model of BPD was established through hyperoxia induction, and lung histological changes were assessed by hematoxylin-eosin staining. Parameters such as radial alveolar count and mean chord length were measured to assess lung function. Mouse and human lung alveolar epithelial cells (MLE12 and A549, respectively) were stimulated with hyperoxia to create an in vitro BPD model. Cell apoptosis was detected using Western blotting and flow cytometry analysis. Our results demonstrated that silencing PVT1 suppressed apoptosis in MLE12 and A549 cells and improved lung function in hyperoxia-stimulated lungs. Additionally, IL-33 reversed the effects of PVT1 both in vivo and in vitro. Through online bioinformatics analysis and RNA-binding protein immunoprecipitation assays, YTHDC1 was identified as a RNA-binding protein (RBP) for both PVT1 and IL-33. We found that PVT1 positively regulated IL-33 expression by recruiting YTHDC1 to mediate m6A modification of IL-33. In conclusion, silencing PVT1 demonstrated beneficial effects in alleviating BPD by facilitating YTHDC1-mediated m6A modification of IL-33. Inhibition of the PVT1/IL-33 axis to suppress apoptosis in lung alveolar epithelial cells may hold promise as a therapeutic approach for managing hyperoxia-induced lung injury in BPD.
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Affiliation(s)
- Tianping Bao
- Department of Neonatology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, No. 1 Western Huanghe Road, Huai'an, 223300, Jiangsu, China
| | - Xiangye Liu
- Department of Neonatology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, No. 1 Western Huanghe Road, Huai'an, 223300, Jiangsu, China
| | - Jian Hu
- Department of Pediatrics, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, Jiangsu, China
| | - Mengmeng Ma
- Department of Neonatology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, No. 1 Western Huanghe Road, Huai'an, 223300, Jiangsu, China
| | - Jingyan Li
- Department of Neonatology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, No. 1 Western Huanghe Road, Huai'an, 223300, Jiangsu, China
| | - Linxia Cao
- Department of Neonatology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, No. 1 Western Huanghe Road, Huai'an, 223300, Jiangsu, China
| | - Bingrui Yu
- Department of Neonatology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, No. 1 Western Huanghe Road, Huai'an, 223300, Jiangsu, China
| | - Huaiping Cheng
- Department of Neonatology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, No. 1 Western Huanghe Road, Huai'an, 223300, Jiangsu, China
| | - Sai Zhao
- Department of Neonatology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, No. 1 Western Huanghe Road, Huai'an, 223300, Jiangsu, China.
| | - Zhaofang Tian
- Department of Neonatology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, No. 1 Western Huanghe Road, Huai'an, 223300, Jiangsu, China.
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Thiriot JD, Liang Y, Gonzales C, Sun J, Yu X, Soong L. Differential cellular immune responses against Orientia tsutsugamushi Karp and Gilliam strains following acute infection in mice. PLoS Negl Trop Dis 2023; 17:e0011445. [PMID: 38091346 PMCID: PMC10752558 DOI: 10.1371/journal.pntd.0011445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 12/27/2023] [Accepted: 12/06/2023] [Indexed: 12/28/2023] Open
Abstract
Scrub typhus is a leading cause of febrile illness in endemic countries due to infection with Orientia tsutsugamushi (Ot), a seriously understudied intracellular bacterium. Pulmonary involvement associated with vascular parasitism in patients is common and can develop into life threatening interstitial pneumonia. The diverse antigenicity of Ot genotypes and inter-strain differences in genome content are connected to varied virulence and clinical outcomes; however, detailed studies of strain-related pulmonary immune responses in human patients or small animal models of infection are lacking. In this study, we have used two clinically prevalent bacterial strains (Karp and Gilliam) to reveal cellular immune responses in inflamed lungs and potential biomarkers of disease severity. The results demonstrate that outbred CD-1 mice are highly susceptible to both Karp and Gilliam strains; however, C57BL/6 (B6) mice were susceptible to Karp, but resistant to Gilliam (with self-limiting infection), corresponding to their tissue bacterial burdens and lung pathological changes. Multicolor flow cytometric analyses of perfused B6 mouse lungs revealed robust and sustained influx and activation of innate immune cells (macrophages, neutrophils, and NK cells), followed by CD4+ and CD8+ T cells, during Karp infection, but such responses were greatly attenuated during Gilliam infection. The robust cellular responses in Karp-infected B6 mice positively correlated with significantly early and high levels of serum cytokine/chemokine protein levels (CXCL1, CCL2/3/5, and G-CSF), as well as pulmonary gene expression (Cxcl1/2, Ccl2/3/4, and Ifng). In vitro infection of B6 mouse-derived primary macrophages also revealed bacterial strain-dependent immune gene expression profiles. This study provided the lines of evidence that highlighted differential tissue cellular responses against Karp vs. Gilliam infection, offering a framework for future investigation of Ot strain-related mechanisms of disease pathogenesis vs. infection control.
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Affiliation(s)
- Joseph D. Thiriot
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Yuejin Liang
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infection and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Casey Gonzales
- Institute for Human Infection and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jiaren Sun
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infection and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Xiaoying Yu
- Department of Biostatistics & Data Science, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Lynn Soong
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infection and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
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Fisher J, Gonzales C, Chroust Z, Liang Y, Soong L. Orientia tsutsugamushi Infection Stimulates Syk-Dependent Responses and Innate Cytosolic Defenses in Macrophages. Pathogens 2022; 12:pathogens12010053. [PMID: 36678402 PMCID: PMC9861896 DOI: 10.3390/pathogens12010053] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/12/2022] [Accepted: 12/26/2022] [Indexed: 12/31/2022] Open
Abstract
Orientia tsutsugamushi is an obligately intracellular bacterium and an etiological agent of scrub typhus. Human studies and animal models of scrub typhus have shown robust type 1-skewed proinflammatory responses during severe infection. Macrophages (MΦ) play a critical role in initiating such responses, yet mechanisms of innate recognition for O. tsutsugamushi remain unclear. In this study, we investigated whether Syk-dependent C-type lectin receptors (CLRs) contribute to innate immune recognition and the generation of proinflammatory responses. To validate the role of CLRs in scrub typhus, we infected murine bone marrow-derived MΦ with O. tsutsugamushi in the presence of selective Syk inhibitors and analyzed a panel of CLRs and proinflammatory markers via qRT-PCR. We found that Mincle/Clec4a and Clec5a transcription was significantly abrogated upon Syk inhibition at 6 h of infection. The effect of Syk inhibition on Mincle protein expression was validated via Western blot. Syk-inhibited MΦ had diminished expression of type 1 cytokines/chemokines (Il12p40, Tnf, Il27p28, Cxcl1) during infection. Additionally, expression of innate immune cytosolic sensors (Mx1 and Oas1-3) was highly induced in the brain of lethally infected mice. We established that Mx1 and Oas1 expression was reduced in Syk-inhibited MΦ, while Oas2, Oas3, and MerTK were not sensitive to Syk inhibition. This study reveals that Syk-dependent CLRs contribute to inflammatory responses against O. tsutsugamushi. It also provides the first evidence for Syk-dependent activation of intracellular defenses during infection, suggesting a role of pattern recognition receptor crosstalk in orchestrating macrophage-mediated responses to this poorly studied bacterium.
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Affiliation(s)
- James Fisher
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
- School of Medicine, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
| | - Casey Gonzales
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
| | - Zachary Chroust
- School of Medicine, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
| | - Yuejin Liang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
- Correspondence: (Y.L.); (L.S.)
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
- Correspondence: (Y.L.); (L.S.)
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Thiriot J, Liang Y, Fisher J, Walker DH, Soong L. Host transcriptomic profiling of CD-1 outbred mice with severe clinical outcomes following infection with Orientia tsutsugamushi. PLoS Negl Trop Dis 2022; 16:e0010459. [PMID: 36417363 PMCID: PMC9683618 DOI: 10.1371/journal.pntd.0010459] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 10/28/2022] [Indexed: 11/24/2022] Open
Abstract
Orientia tsutsugamushi is an obligately intracellular bacterium with endothelial tropism and can cause mild to lethal scrub typhus in humans. No vaccine is available for this reemerging and severely neglected infection. Previous scrub typhus studies have utilized inbred mice, yet such models have intrinsic limitations. Thus, the development of suitable mouse models that better mimic human diseases is in great need for immunologic investigation and future vaccine studies. This study is aimed at establishing scrub typhus in outbred CD-1 mice and defining immune biomarkers related to disease severity. CD-1 mice received O. tsutsugamushi Karp strain via the i.v. route; major organs were harvested at 2-12 days post-infection for kinetic analyses. We found that for our given infection doses, CD-1 mice were significantly more susceptible (90-100% lethal) than were inbred C57BL/6 mice (0-10% lethal). Gross pathology of infected CD-1 mouse organs revealed features that mimicked human scrub typhus, including pulmonary edema, interstitial pneumonia, perivascular lymphocytic infiltrates, and vasculitis. Alteration in angiopoietin/receptor expression in inflamed lungs implied endothelial dysfunction. Lung immune gene profiling using NanoString analysis displayed a Th1/CD8-skewed, but Th2 repressed profile, including novel biomarkers not previously investigated in other scrub typhus models. Bio-plex analysis revealed a robust inflammatory response in CD-1 mice as evidenced by increased serum cytokine and chemokine levels, correlating with immune cell recruitment during the severe stages of the disease. This study provides an important framework indicating a value of CD-1 mice for delineating host susceptibility to O. tsutsugamushi, immune dysregulation, and disease pathogenesis. This preclinical model is particularly useful for future translational and vaccine studies for severe scrub typhus.
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Affiliation(s)
- Joseph Thiriot
- Department of Microbiology and Immunology, 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
- Institute for Human Infection and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - James Fisher
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - David H. Walker
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infection and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail:
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Fernander EM, Adogamhe P, Datta D, Bond C, Zhao Y, Bangirana P, Conroy AL, Opoka RO, John CC. Elevated Plasma Soluble ST2 Levels are Associated With Neuronal Injury and Neurocognitive Impairment in Children With Cerebral Malaria. Pathog Immun 2022; 7:60-80. [PMID: 35800259 PMCID: PMC9254869 DOI: 10.20411/pai.v7i1.499] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/08/2022] [Indexed: 11/23/2022] Open
Abstract
Background Murine experimental cerebral malaria studies suggest both protective and deleterious central nervous system effects from alterations in the interleukin-33 (IL-33)/ST2 pathway. Methods We assessed whether soluble ST2 (sST2) was associated with neuronal injury or cognitive impairment in a cohort of Ugandan children with cerebral malaria (CM, n=224) or severe malarial anemia (SMA, n=193). Results Plasma concentrations of sST2 were higher in children with CM than in children with SMA or in asymptomatic community children. Cerebrospinal fluid (CSF) sST2 levels were elevated in children with CM compared with North American children. Elevated plasma and CSF ST2 levels in children with CM correlated with increased endothelial activation and increased plasma and CSF levels of tau, a marker of neuronal injury. In children with CM who were ≥5 years of age at the time of their malaria episode, but not in children <5 years of age, elevated risk factor-adjusted plasma levels of sST2 were associated with worse scores for overall cognitive ability and attention over a 2-year follow-up. Conclusions The study findings suggest that sST2 may contribute to neuronal injury and long-term neurocognitive impairment in older children with CM.
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Affiliation(s)
- Elizabeth M. Fernander
- Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Pontian Adogamhe
- Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Dibyadyuti Datta
- Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Caitlin Bond
- Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Yi Zhao
- Department of Biostatistics and Health Data Science, Indiana University School of Medicine, Indianapolis, IN
| | - Paul Bangirana
- Department of Psychiatry, Makerere University, Kampala, Uganda
| | - Andrea L. Conroy
- Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Robert O. Opoka
- Department of Paediatrics and Child Health, Makerere University, Kampala, Uganda
| | - Chandy C. John
- Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
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Liang Y, Fisher J, Gonzales C, Trent B, Card G, Sun J, Tumanov AV, Soong L. Distinct Role of TNFR1 and TNFR2 in Protective Immunity Against Orientia tsutsugamushi Infection in Mice. Front Immunol 2022; 13:867924. [PMID: 35479068 PMCID: PMC9035742 DOI: 10.3389/fimmu.2022.867924] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 03/21/2022] [Indexed: 02/05/2023] Open
Abstract
Infection with Orientia tsutsugamushi, an obligate intracellular bacterium, can cause mild or severe scrub typhus. Some patients develop acute lung injury, multi-organ failure, and fatal infection; however, little is known regarding key immune mediators that mediate infection control or disease pathogenesis. Using murine models of scrub typhus, we demonstrated in this study the requirement of TNF-TNFR signaling in protective immunity against this infection. Mice lacking both TNF receptors (TNFR1 and TNFR2) were highly susceptible to O. tsutsugamushi infection, displaying significantly increased tissue bacterial burdens and succumbing to infection by day 9, while most wild-type mice survived through day 20. This increased susceptibility correlated with poor activation of cellular immunity in inflamed tissues. Flow cytometry of lung- and spleen-derived cells revealed profound deficiencies in total numbers and activation status of NK cells, neutrophils, and macrophages, as well as CD4 and CD8 T cells. To define the role of individual receptors in O. tsutsugamushi infection, we used mice lacking either TNFR1 or TNFR2. While deficiency in either receptor alone was sufficient to increase host susceptibility to the infection, TNFR1 and TNFR2 played a distinct role in cellular responses. TNF signaling through TNFR1 promoted inflammatory responses and effector T cell expansion, while TNFR2 signaling was associated with anti-inflammatory action and tissue homeostasis. Moreover, TNFRs played an intrinsic role in CD8+ T cell activation, revealing an indispensable role of TNF in protective immunity against O. tsutsugamushi infection.
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Affiliation(s)
- Yuejin Liang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
| | - James Fisher
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Casey Gonzales
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Brandon Trent
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Galen Card
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Alexei V. Tumanov
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
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Orientia tsutsugamushi Nucleomodulin Ank13 Exploits the RaDAR Nuclear Import Pathway To Modulate Host Cell Transcription. mBio 2021; 12:e0181621. [PMID: 34340535 PMCID: PMC8406279 DOI: 10.1128/mbio.01816-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Orientia tsutsugamushi is the etiologic agent of scrub typhus, the deadliest of all diseases caused by obligate intracellular bacteria. Nucleomodulins, bacterial effectors that dysregulate eukaryotic transcription, are being increasingly recognized as key virulence factors. How they translocate into the nucleus and their functionally essential domains are poorly defined. We demonstrate that Ank13, an O. tsutsugamushi effector conserved among clinical isolates and expressed during infection, localizes to the nucleus in an importin β1-independent manner. Rather, Ank13 nucleotropism requires an isoleucine at the thirteenth position of its fourth ankyrin repeat, consistent with utilization of eukaryotic RaDAR (RanGDP-ankyrin repeats) nuclear import. RNA-seq analyses of cells expressing green fluorescent protein (GFP)-tagged Ank13, nucleotropism-deficient Ank13I127R, or Ank13ΔF-box, which lacks the F-box domain essential for interacting with SCF ubiquitin ligase, revealed Ank13 to be a nucleomodulin that predominantly downregulates transcription of more than 2,000 genes. Its ability to do so involves its nucleotropism and F-box in synergistic and mutually exclusive manners. Ank13 also acts in the cytoplasm to dysregulate smaller cohorts of genes. The effector’s toxicity in yeast heavily depends on its F-box and less so on its nucleotropism. Genes negatively regulated by Ank13 include those involved in the inflammatory response, transcriptional control, and epigenetics. Importantly, the majority of genes that GFP-Ank13 most strongly downregulates are quiescent or repressed in O. tsutsugamushi-infected cells when Ank13 expression is strongest. Ank13 is the first nucleomodulin identified to coopt RaDAR and a multifaceted effector that functions in the nucleus and cytoplasm via F-box-dependent and -independent mechanisms to globally reprogram host cell transcription.
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Orientia tsutsugamushi selectively stimulates the C-type lectin receptor Mincle and type 1-skewed proinflammatory immune responses. PLoS Pathog 2021; 17:e1009782. [PMID: 34320039 PMCID: PMC8351992 DOI: 10.1371/journal.ppat.1009782] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 08/09/2021] [Accepted: 07/03/2021] [Indexed: 12/20/2022] Open
Abstract
Orientia tsutsugamushi is an obligately intracellular bacterium and the etiological agent of scrub typhus. The lung is a major target organ of infection, displaying type 1-skewed proinflammatory responses. Lung injury and acute respiratory distress syndrome are common complications of severe scrub typhus; yet, their underlying mechanisms remain unclear. In this study, we investigated whether the C-type lectin receptor (CLR) Mincle contributes to immune recognition and dysregulation. Following lethal infection in mice, we performed pulmonary differential expression analysis with NanoString. Of 671 genes examined, we found 312 significantly expressed genes at the terminal phase of disease. Mincle (Clec4e) was among the top 5 greatest up-regulated genes, accompanied with its signaling partners, type 1-skewing chemokines (Cxcr3, Ccr5, and their ligands), as well as Il27. To validate the role of Mincle in scrub typhus, we exposed murine bone marrow-derived macrophages (MΦ) to live or inactivated O. tsutsugamushi and analyzed a panel of CLRs and proinflammatory markers via qRT-PCR. We found that while heat-killed bacteria stimulated transitory Mincle expression, live bacteria generated a robust response in MΦ, which was validated by indirect immunofluorescence and western blot. Notably, infection had limited impact on other tested CLRs or TLRs. Sustained proinflammatory gene expression in MΦ (Cxcl9, Ccl2, Ccl5, Nos2, Il27) was induced by live, but not inactivated, bacteria; infected Mincle-/- MΦ significantly reduced proinflammatory responses compared with WT cells. Together, this study provides the first evidence for a selective expression of Mincle in sensing O. tsutsugamushi and suggests a potential role of Mincle- and IL-27-related pathways in host responses to severe infection. Additionally, it provides novel insight into innate immune recognition of this poorly studied bacterium.
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Tantibhedhyangkul W, Matamnan S, Longkunan A, Boonwong C, Khowawisetsut L. Endothelial Activation in Orientia tsutsugamushi Infection Is Mediated by Cytokine Secretion From Infected Monocytes. Front Cell Infect Microbiol 2021; 11:683017. [PMID: 34368012 PMCID: PMC8340038 DOI: 10.3389/fcimb.2021.683017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 07/06/2021] [Indexed: 12/24/2022] Open
Abstract
Scrub typhus, caused by Orientia tsutsugamushi, is a common systemic infection in Asia. Delay in diagnosis and treatment can lead to vasculitis in the visceral organs and other complications. The mechanisms that drive endothelial activation and the inflammatory response in O. tsutsugamushi infection remain unknown. In addition, the interaction between monocytes and endothelial cells is still unclear. Here we demonstrate that O. tsutsugamushi-infected human dermal microvascular endothelial cells produced moderate levels of chemokines and low levels of IL-6 and IFN-β, but not TNF or IL-1β. Recombinant TNF and cytokine-rich supernatants from infected monocytes markedly enhanced chemokine production in infected endothelial cells. We also show that TNF and monocyte supernatants, but not O. tsutsugamushi infection of endothelial cells per se, upregulated the endothelial cell surface expression of ICAM-1, E-selectin, and tissue factor. This finding was consistent with the inability of O. tsutsugamushi to induce cytokine secretion from endothelial cells. The upregulation of surface molecules after stimulation with monocyte supernatants was significantly reduced by neutralizing anti-TNF antibodies. These results suggest that endothelial cell activation and response are mainly mediated by inflammatory cytokines secreted from monocytes.
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Affiliation(s)
- Wiwit Tantibhedhyangkul
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Sutthicha Matamnan
- Graduate Program in Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Research Division, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Asma Longkunan
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Graduate Program in Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Chawikan Boonwong
- Research Division, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Ladawan Khowawisetsut
- Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
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11
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Yu MY, Kwon S, Moon JJ, Kim YC, Song EY, Lee H, Moon KC, Ha J, Kim DK, Han SW, Kim GH, Kim YS, Yang SH. Role of the IL-33/ST2 pathway in renal allograft rejection. Exp Cell Res 2021; 405:112705. [PMID: 34166678 DOI: 10.1016/j.yexcr.2021.112705] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 06/04/2021] [Accepted: 06/09/2021] [Indexed: 11/25/2022]
Abstract
The interleukin-33 (IL-33)/suppression of tumorigenicity 2 (ST2) pathway modulates immune response and inflammation, associated with allograft dysfunction and rejection. We hypothesized that IL-33/ST2 is a marker of renal allograft rejection and IL-33/ST2 expression may differ according to rejection type. IL-33/ST2 expression was measured in sera and kidney tissues from recipients with acute antibody-mediated rejection (AAMR), acute cell-mediated rejection (ACMR), chronic antibody-mediated rejection (CAMR), and healthy controls. The soluble ST2 and IL-33/ST2 expression levels were higher in participants with all three rejection types than in controls. Although the expression levels in recipients with AAMR and ACMR were significantly higher than those with CAMR, there was no significant difference between the expression levels in AAMR and ACMR. Although IL-33, IL-8, and fibronectin expression were significantly increased after the addition of the recipients' serum in primary cultured human renal proximal tubular epithelial cells, the levels decreased after treatment with an anti-ST2 antibody. Furthermore, the anti-ST2 antibody specifically suppressed the upregulation of the mixed lymphocyte reaction. Boyden chamber assays demonstrated that anti-ST2 antibody abrogated chemotaxis induced by recombinant IL-33. Thus, IL-33 and ST2 are potent mediators of rejection. Treatment with an anti-ST2 antibody ameliorates rejection and could be a potential therapeutic strategy for renal allograft rejection.
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Affiliation(s)
- Mi-Yeon Yu
- Department of Internal Medicine, Hanyang University Guri Hospital, Guri, South Korea; Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea
| | - Soie Kwon
- Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea
| | - Jong Joo Moon
- Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea
| | - Yong-Chul Kim
- Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea
| | - Eun Young Song
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul, South Korea
| | - Hajeong Lee
- Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea; Kidney Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Kyung Chul Moon
- Kidney Research Institute, Seoul National University College of Medicine, Seoul, South Korea; Department of Pathology, Seoul National University Hospital, Seoul, South Korea
| | - Jongwon Ha
- Department of Surgery, Seoul National University Hospital, Seoul, South Korea
| | - Dong Ki Kim
- Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea; Kidney Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Sang-Woong Han
- Department of Internal Medicine, Hanyang University Guri Hospital, Guri, South Korea; Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea
| | - Gheun-Ho Kim
- Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea
| | - Yon Su Kim
- Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea; Kidney Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Seung Hee Yang
- Kidney Research Institute, Seoul National University College of Medicine, Seoul, South Korea; Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea.
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12
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Banerjee A, Kulkarni S. Orientia tsutsugamushi: The dangerous yet neglected foe from the East. Int J Med Microbiol 2020; 311:151467. [PMID: 33338890 DOI: 10.1016/j.ijmm.2020.151467] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 10/06/2020] [Accepted: 11/25/2020] [Indexed: 01/22/2023] Open
Abstract
Orientia tsutsugamushi (OT), the causative agent of the vector-borne Scrub typhus zoonotic disease in humans, is a unique microorganism that exists in the Asia-Pacific region since a long time. In spite of its occurrence, the organism had been neglected until recent years. Humans are the accidental dead-end hosts of O. tsutsugamushi and display manifestations which are both severe and misleading. The vast antigenic diversity of OT and non-pathognomic symptoms of Scrub typhus, create hurdles in the clinical management of the disease and impede the OT-research. Many countries in the Asia-Pacific region have reported the resurgence of OT- infections and have raised concerns for its expanding distribution. This has triggered the development of advanced techniques for diagnosis and research on exploring a successful vaccine candidate to reduce the burden of the disease. Thus, the aim of this systematic review is to provide an update on the recent advances in the OT-research and highlight the key areas that have remained obscure and demand attention.
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Affiliation(s)
- Anwesha Banerjee
- ICMR-National AIDS Research Institute, Bhosari, Pune, 411026, India
| | - Smita Kulkarni
- ICMR-National AIDS Research Institute, Bhosari, Pune, 411026, India.
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13
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Dual RNA-seq of Orientia tsutsugamushi informs on host-pathogen interactions for this neglected intracellular human pathogen. Nat Commun 2020; 11:3363. [PMID: 32620750 PMCID: PMC7335160 DOI: 10.1038/s41467-020-17094-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 06/11/2020] [Indexed: 12/12/2022] Open
Abstract
Studying emerging or neglected pathogens is often challenging due to insufficient information and absence of genetic tools. Dual RNA-seq provides insights into host-pathogen interactions, and is particularly informative for intracellular organisms. Here we apply dual RNA-seq to Orientia tsutsugamushi (Ot), an obligate intracellular bacterium that causes the vector-borne human disease scrub typhus. Half the Ot genome is composed of repetitive DNA, and there is minimal collinearity in gene order between strains. Integrating RNA-seq, comparative genomics, proteomics, and machine learning to study the transcriptional architecture of Ot, we find evidence for wide-spread post-transcriptional antisense regulation. Comparing the host response to two clinical isolates, we identify distinct immune response networks for each strain, leading to predictions of relative virulence that are validated in a mouse infection model. Thus, dual RNA-seq can provide insight into the biology and host-pathogen interactions of a poorly characterized and genetically intractable organism such as Ot.
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14
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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] [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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15
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Temporal analysis of mRNA expression profiles in Orientia infected C3HeB/FeJ mouse. BMC Microbiol 2020; 20:3. [PMID: 31906849 PMCID: PMC6945539 DOI: 10.1186/s12866-019-1684-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 12/15/2019] [Indexed: 01/31/2023] Open
Abstract
Background Scrub typhus causes up to 35% mortality if left untreated. One billion people living in the endemic regions are at risk. In spite of its heavy disease burden in some of the most populated areas in the world, there is no vaccine available. Although the disease can be effectively treated by proper antibiotics, timely and accurate diagnosis remains a challenge. Orientia tsutsugamushi infects a variety of mammalian cells in vitro and replicates in the cytoplasm of the infected cells. Microarray analysis has been used extensively to study host-pathogen interactions in in vitro models to understand pathogenesis. However there is a lack of in vivo studies. Results In this study, C3HeB/FeJ (C3H) mice were infected by O. tsutsugamushi via the intraperitoneal route and monitored gene expression at 10 different time points post infection. We observed two distinct types of expression profiles in the genes that we analyzed. There are two valleys (4–18 h and 2–4 days) with low number of differentially expressed genes (DEG) with three peaks with high number of DEG at 2 h, 1-day and 7-day post infection. Further analysis revealed that pathways like complement and coagulation cascade, and blood clotting cascade pathways showed significant global changes throughout entire time course. Real time quantitative Polymerase Chain Reaction (RT-qPCR) confirmed the change of expression for genes involved in complement and coagulation cascade. These results suggested dynamic regulation of the complement and coagulation cascades throughout most of the time post infection while some other specific pathways, such as fatty acid metabolism and tryptophan metabolism, are turned on or off at certain times post infection. Conclusions The findings highlight the complex interconnection among all different biological pathways. It is conceivable that specific pathways such as cell growth control and cell development in the host are affected by Orientia in the initial phase of infection for Orientia to grow intracellularly. Once Orientia is replicating successfully inside the host as infection progresses, the infection could activate pathways involved in cellular immune responses to defend for host cell survival and try to eliminate the pathogen.
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16
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Trent B, Fisher J, Soong L. Scrub Typhus Pathogenesis: Innate Immune Response and Lung Injury During Orientia tsutsugamushi Infection. Front Microbiol 2019; 10:2065. [PMID: 31555249 PMCID: PMC6742975 DOI: 10.3389/fmicb.2019.02065] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/22/2019] [Indexed: 01/28/2023] Open
Abstract
Scrub typhus is an understudied, potentially lethal disease caused by infection with Orientia tsutsugamushi. Despite causing an estimated 1 million cases per year and an increasing global presence, mechanisms of scrub typhus pathogenesis remain unclear. One of the most life-threatening conditions that can arise in scrub typhus patients is acute respiratory distress syndrome (ARDS). The development of ARDS is a complex process; some of its pathological hallmarks, including prolonged recruitment of inflammatory immune cells to the lung and vasculature damage, have been observed in humans and/or animal models of O. tsutsugamushi infection. Although different cell types and mechanisms may contribute to ARDS development during O. tsutsugamushi infection, this review highlights our current evidence of pulmonary endothelial activation and damage, the potential roles of neutrophils and macrophages in the lung, and the knowledge gaps in this field. Continued investigation of the lung microenvironment and cellular interactions will help elucidate disease pathogenesis and possible treatment during scrub typhus.
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Affiliation(s)
- Brandon Trent
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - James Fisher
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Lynn Soong
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
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17
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Cameron GJM, Cautivo KM, Loering S, Jiang SH, Deshpande AV, Foster PS, McKenzie ANJ, Molofsky AB, Hansbro PM, Starkey MR. Group 2 Innate Lymphoid Cells Are Redundant in Experimental Renal Ischemia-Reperfusion Injury. Front Immunol 2019; 10:826. [PMID: 31057549 PMCID: PMC6477147 DOI: 10.3389/fimmu.2019.00826] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/28/2019] [Indexed: 12/21/2022] Open
Abstract
Acute kidney injury (AKI) can be fatal and is a well-defined risk factor for the development of chronic kidney disease. Group 2 innate lymphoid cells (ILC2s) are innate producers of type-2 cytokines and are critical regulators of homeostasis in peripheral organs. However, our knowledge of their function in the kidney is relatively limited. Recent evidence suggests that increasing ILC2 numbers by systemic administration of recombinant interleukin (IL)-25 or IL-33 protects against renal injury. Whilst ILC2s can be induced to protect against ischemic- or chemical-induced AKI, the impact of ILC2 deficiency or depletion on the severity of renal injury is unknown. Firstly, the phenotype and location of ILC2s in the kidney was assessed under homeostatic conditions. Kidney ILC2s constitutively expressed high levels of IL-5 and were located in close proximity to the renal vasculature. To test the functional role of ILC2s in the kidney, an experimental model of renal ischemia-reperfusion injury (IRI) was used and the severity of injury was assessed in wild-type, ILC2-reduced, ILC2-deficient, and ILC2-depleted mice. Surprisingly, there were no differences in histopathology, collagen deposition or mRNA expression of injury-associated (Lcn2), inflammatory (Cxcl1, Cxcl2, and Tnf) or extracellular matrix (Col1a1, Fn1) factors following IRI in the absence of ILC2s. These data suggest the absence of ILC2s does not alter the severity of renal injury, suggesting possible redundancy. Therefore, other mechanisms of type 2-mediated immune cell activation likely compensate in the absence of ILC2s. Hence, a loss of ILC2s is unlikely to increase susceptibility to, or severity of AKI.
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Affiliation(s)
- Guy J M Cameron
- Priority Research Centre's GrowUpWell and Healthy Lungs, School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Kelly M Cautivo
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Svenja Loering
- Priority Research Centre's GrowUpWell and Healthy Lungs, School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Simon H Jiang
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, Australia National University, Canberra, ACT, Australia.,Department of Renal Medicine, The Canberra Hospital, Canberra, ACT, Australia
| | - Aniruddh V Deshpande
- Priority Research Centre's GrowUpWell and Healthy Lungs, School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, New Lambton Heights, NSW, Australia.,The John Hunter Children's Hospital, New Lambton Heights, NSW, Australia
| | - Paul S Foster
- Priority Research Centre's GrowUpWell and Healthy Lungs, School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Andrew N J McKenzie
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Ari B Molofsky
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Philip M Hansbro
- Priority Research Centre's GrowUpWell and Healthy Lungs, School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, New Lambton Heights, NSW, Australia.,Centre for inflammation, Centenary Institute, Sydney, NSW, Australia.,Faculty of Science, University of Technology, Ultimo, NSW, Australia
| | - Malcolm R Starkey
- Priority Research Centre's GrowUpWell and Healthy Lungs, School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
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18
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Soong L. Dysregulated Th1 Immune and Vascular Responses in Scrub Typhus Pathogenesis. THE JOURNAL OF IMMUNOLOGY 2019; 200:1233-1240. [PMID: 29431689 DOI: 10.4049/jimmunol.1701219] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 11/30/2017] [Indexed: 12/25/2022]
Abstract
Scrub typhus is an emerging, insect-transmitted disease caused by Orientia tsutsugamushi, a Gram- and LPS-negative bacterium that replicates freely within professional phagocytes and endothelial cells. Scrub typhus is prevalent with high mortality rates, but information regarding its molecular pathogenesis, microbial virulence determinants, and key immune responses is limited. Improved animal models have recently been developed that respectively resemble the pathological features of self-limiting or severe scrub typhus in humans. Strong activation of Th1 and CD8, but not Th2 and regulatory T, immune responses, accompanied by altered angiopoietin/Tie2-related regulation, are hallmarks of lethal infection in murine models. This review, based primarily on recent advances from clinical and experimental studies, highlights tissue- and endothelial cell-specific biomarkers that are indicative of immune dysregulation. The potential roles of neutrophils and damage-associated molecular pattern molecules at late stages of disease are discussed in the context of vascular leakage, pulmonary and renal injury, and scrub typhus pathogenesis.
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Affiliation(s)
- Lynn Soong
- Department of Microbiology and Immunology, Center for Tropical Diseases, Center for Biodefense and Emerging Infectious Diseases, Sealy Center for Vaccine Development, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555; and .,Department of Pathology, Center for Tropical Diseases, Center for Biodefense and Emerging Infectious Diseases, Sealy Center for Vaccine Development, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555
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19
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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] [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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20
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Shi H, Han X, Sun Y, Shang C, Wei M, Ba X, Zeng X. Chemokine (C-X-C motif) ligand 1 and CXCL2 produced by tumor promote the generation of monocytic myeloid-derived suppressor cells. Cancer Sci 2018; 109:3826-3839. [PMID: 30259595 PMCID: PMC6272093 DOI: 10.1111/cas.13809] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 08/29/2018] [Accepted: 09/14/2018] [Indexed: 12/16/2022] Open
Abstract
Accumulation of myeloid‐derived suppressor cells (MDSC) in tumor‐bearing hosts is a hallmark of tumor‐associated inflammation, which is thought to be a barrier to immunosurveillance. Multiple factors secreted by tumor cells and tumor stromal cells are reported to be involved in promoting the expansion of MDSC. Herein, we showed that s.c. inoculation of tumor cells and i.v. injection of tumor‐conditioned medium increased the number of MDSC. Subsequent investigation elucidated that chemokine (C‐X‐C motif) ligand 1 (CXCL1) and CXCL2, which were originally characterized as the chemokines of neutrophils, specifically promoted the expansion of monocytic MDSC (mo‐MDSC), a subtype of MDSC, in the presence of granulocyte‐macrophage colony‐stimulating factor. Depletion of CXCL1 or CXCL2 in B16F10 cells or in B16F10‐bearing mice noticeably decreased the generation of mo‐MDSC in bone marrow. Moreover, we found that, in addition to the tumor cells, tumor‐infiltrated CD11b+ myeloid cells also expressed CXCL1 and CXCL2. Furthermore, CXCL1‐ and CXCL2‐induced increase of mo‐MDSC was not correlated with chemotaxis, proliferation or apoptosis of mo‐MDSC. These findings show a novel role of CXCL1 and CXCL2 in promoting mo‐MDSC generation by favoring the differentiation of bone marrow cells in tumor‐bearing conditions, which suggests that inhibition of CXCL1 and CXCL2 could decrease mo‐MDSC generation and improve host immunosurveillance.
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Affiliation(s)
- Huifang Shi
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Science, Northeast Normal University, Changchun, China.,People's Hospital of Rizhao, Rizhao, China
| | - Xiaoqing Han
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Science, Northeast Normal University, Changchun, China
| | - Yingying Sun
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Science, Northeast Normal University, Changchun, China
| | - Chao Shang
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Science, Northeast Normal University, Changchun, China
| | - Min Wei
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Science, Northeast Normal University, Changchun, China
| | - Xueqing Ba
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Science, Northeast Normal University, Changchun, China
| | - Xianlu Zeng
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Science, Northeast Normal University, Changchun, China
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21
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Jiang L, Morris EK, Aguilera-Olvera R, Zhang Z, Chan TC, Shashikumar S, Chao CC, Casares SA, Ching WM. Dissemination of Orientia tsutsugamushi, a Causative Agent of Scrub Typhus, and Immunological Responses in the Humanized DRAGA Mouse. Front Immunol 2018; 9:816. [PMID: 29760694 PMCID: PMC5936984 DOI: 10.3389/fimmu.2018.00816] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 04/04/2018] [Indexed: 12/23/2022] Open
Abstract
Scrub typhus is caused by Orientia tsutsugamushi, an obligated intracellular bacterium that affects over one million people per year. Several mouse models have been used to study its pathogenesis, disease immunology, and for testing vaccine candidates. However, due to the intrinsic differences between the immune systems in mouse and human, these mouse models could not faithfully mimic the pathology and immunological responses developed by human patients, limiting their value in both basic and translational studies. In this study, we have tested for the first time, a new humanized mouse model through footpad inoculation of O. tsutsugamushi in DRAGA (HLA-A2.HLA-DR4.Rag1KO.IL2RγcKO.NOD) mice with their human immune system reconstituted by infusion of HLA-matched human hematopoietic stem cells from umbilical cord blood. Upon infection, Orientia disseminated into various organs of DRAGA mice resulted in lethality in a dose-dependent manner, while all C3H/HeJ mice infected by the same route survived. Tissue-specific lesions associated with inflammation and/or necroses were observed in multiple organs of infected DRAGA mice. Consistent with the intracellular nature of Orientia, strong Th1, but subdued Th2 responses were elicited as reflected by the human cytokine profiles in sera from infected mice. Interestingly, the percentage of both activated and regulatory (CD4+FOXP3+) human T cells were elevated in spleen tissues of infected mice. After immunization with irradiated whole cell Orientia, humanized DRAGA mice showed a significant activation of human T cells as evidenced by increased number of human CD4+ and CD8+ T cells. Specific human IgM and IgG antibodies were developed after repetitive immunization. The humanized DRAGA mouse model represents a new pre-clinical model for studying Orientia-human interactions and also for testing vaccines and novel therapeutics for scrub typhus.
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Affiliation(s)
- Le Jiang
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
| | - Erin K Morris
- Veterinary Services Program, Department of Pathology Services, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Rodrigo Aguilera-Olvera
- US Military Malaria Vaccine Program, Naval Medical Research Center, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Zhiwen Zhang
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
| | - Teik-Chye Chan
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
| | - Soumya Shashikumar
- US Military Malaria Vaccine Program, Naval Medical Research Center, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Chien-Chung Chao
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States.,Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Sofia A Casares
- US Military Malaria Vaccine Program, Naval Medical Research Center, Walter Reed Army Institute of Research, Silver Spring, MD, United States.,Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Wei-Mei Ching
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States.,Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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22
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Chen WY, Yang JL, Wu YH, Li LC, Li RF, Chang YT, Dai LH, Wang WC, Chang YJ. IL-33/ST2 axis mediates hyperplasia of intrarenal urothelium in obstructive renal injury. Exp Mol Med 2018; 50:1-11. [PMID: 29674622 PMCID: PMC5938009 DOI: 10.1038/s12276-018-0047-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 11/20/2017] [Accepted: 12/21/2017] [Indexed: 12/14/2022] Open
Abstract
The monolayered intrarenal urothelium covers the renal papilla and ureteropelvic junction (UPJ). In response to increased renal pressure during obstruction or ischemic injuries, intrarenal urothelial cells begin to proliferate and form a multilayered urothelium. Little is known regarding the mechanism and pathophysiological role of urothelium hyperplasia during renal obstruction. In this study, we investigated the expression of interleukin (IL)-33, an IL-1 family cytokine, in kidneys with unilateral ureteral obstruction (UUO)-induced obstructive injury. IL-33 levels in hydronephrotic urine and serum were upregulated 2 days after UUO. The number of ST2-expressing immune cells was increased in the UUO kidney. We found that IL-33 was upregulated in vimentin-positive cells in the cortical and medullar layers and the UPJ stroma. Moreover, IL-33 expression was predominantly induced in multilayered keratin 5-positive urothelial cells in the UPJ. IL-33 was not detected in terminally differentiated superficial umbrella cells expressing uroplakin 3a. In vivo, we confirmed that deficiency of IL33 or its receptor ST2 attenuated UUO-induced hyperplasia of the UPJ urothelium. Deficiency of IL33 attenuated the expression of UUO-induced type 2 inflammatory cytokines and upregulated uroplakins and urothelial differentiation signaling in UPJ tissues. Our results collectively suggest that the IL-33/ST2 axis mediates the activation of innate immune responses and contributes to urothelial hyperplasia by regulating urothelial differentiation in obstructive kidney injury.
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Affiliation(s)
- Wei-Yu Chen
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
| | - Jenq-Lin Yang
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Yi-Hsiu Wu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Lung-Chih Li
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.,Division of Nephrology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Ru-Fang Li
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Ya-Ting Chang
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Lo-Hsin Dai
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Wan-Chen Wang
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Ya-Jen Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
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23
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Díaz FE, Abarca K, Kalergis AM. An Update on Host-Pathogen Interplay and Modulation of Immune Responses during Orientia tsutsugamushi Infection. Clin Microbiol Rev 2018; 31:e00076-17. [PMID: 29386235 PMCID: PMC5967693 DOI: 10.1128/cmr.00076-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The obligate intracellular bacterium Orientia tsutsugamushi is the causative agent of scrub typhus in humans, a serious mite-borne disease present in a widespread area of endemicity, which affects an estimated 1 million people every year. This disease may exhibit a broad range of presentations, ranging from asymptomatic to fatal conditions, with the latter being due to disseminated endothelial infection and organ injury. Unique characteristics of the biology and host-pathogen interactions of O. tsutsugamushi, including the high antigenic diversity among strains and the highly variable, short-lived memory responses developed by the host, underlie difficulties faced in the pursuit of an effective vaccine, which is an imperative need. Other factors that have hindered scientific progress relative to the infectious mechanisms of and the immune response triggered by this bacterium in vertebrate hosts include the limited number of mechanistic studies performed on animal models and the lack of genetic tools currently available for this pathogen. However, recent advances in animal model development are promising to improve our understanding of host-pathogen interactions. Here, we comprehensively discuss the recent advances in and future perspectives on host-pathogen interactions and the modulation of immune responses related to this reemerging disease, highlighting the role of animal models.
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Affiliation(s)
- Fabián E Díaz
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Katia Abarca
- Departamento en Enfermedades Infecciosas e Inmunología Pediátricas, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alexis M Kalergis
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
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24
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Metabolic characterization of serum from mice challenged with Orientia tsutsugamushi-infected mites. New Microbes New Infect 2018; 23:70-76. [PMID: 29692908 PMCID: PMC5913361 DOI: 10.1016/j.nmni.2018.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 01/18/2018] [Accepted: 01/18/2018] [Indexed: 01/31/2023] Open
Abstract
Scrub typhus is an acute zoonosis caused by the obligate intracellular Gram-negative bacterium Orientia tsutsugamushi. To better understand the host response elicited by natural infection by chigger feeding, ICR mice were infected by Leptotrombidium chiangraiensis (Lc1) chiggers, and the metabolic profiles of their serum were examined over several time points after initiation of feeding. ICR mice were infected by either naive Lc1 chiggers (i.e. not infected by O. tsutsugamushi, NLc1) or O. tsutsugamushi–infected Lc1 chiggers (OLc1). Serum was collected from both groups of mice at 6 hours and 10 days after initiation of feeding. Metabolites were extracted from the serum and analysed by ultra performance liquid chromatography–tandem mass spectrometry. The resulting ion/chromatographic features were matched to a library of chemical standards for identification and quantification. Biochemicals that differed significantly between the experimental groups were identified using Welch's two-sample t tests; p ≤ 0.05 was considered statistically significant. A number of biochemicals linked to immune function were found to be significantly altered between mice infected by the NLc1 and OLc1 chiggers, including itaconate, kynurenine and histamine. Several metabolites linked to energy production were also found to be altered in the animals. In addition lipid and carbohydrate metabolism, bile acid and phospholipid homeostasis, and nucleotide metabolism were also found to be different in these two groups of mice. Markers of stress and food intake were also significantly altered. Global untargeted metabolomic characterization revealed significant differences in the biochemical profiles of mice infected by the NLc1 versus OLc1 chiggers. These findings provide an important platform for further investigation of the host responses associated with chigger-borne O. tsutsugamushi infections.
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25
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Soong L, Shelite TR, Xing Y, Kodakandla H, Liang Y, Trent BJ, Horton P, Smith KC, Zhao Z, Sun J, Bouyer DH, Cai J. Type 1-skewed neuroinflammation and vascular damage associated with Orientia tsutsugamushi infection in mice. PLoS Negl Trop Dis 2017; 11:e0005765. [PMID: 28742087 PMCID: PMC5542690 DOI: 10.1371/journal.pntd.0005765] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 08/03/2017] [Accepted: 06/30/2017] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Scrub typhus is a life-threatening disease, due to infection with O. tsutsugamushi, a Gram-negative bacterium that preferentially replicates in endothelial cells and professional phagocytes. Meningoencephalitis has been reported in scrub typhus patients and experimentally-infected animals; however, the neurological manifestation and its underlying mechanisms remain poorly understood. To address this issue, we focused on Orientia tsutsugamushi Karp strain (OtK), and examined host responses in the brain during lethal versus self-healing scrub typhus disease in our newly established murine models. PRINCIPLE FINDINGS Following inoculation with a lethal dose of OtK, mice had a significant increase in brain transcripts related to pathogen-pattern recognition receptors (TLR2, TLR4, TLR9), type-1 responses (IFN-γ, TNF-α, CXCL9, CXCR3), and endothelial stress/damage such as angiopoietins, but a rapid down-regulation of Tie2. Sublethal infection displayed similar trends, implying the development of type 1-skewed proinflammatory responses in infected brains, independent of time and disease outcomes. Focal hemorrhagic lesions and meningitis were evident in both infection groups, but pathological changes were more diffuse and frequent in lethal infection. At 6-10 days of lethal infection, the cortex and cerebellum sections had increased ICAM-1-positive staining in vascular cells, as well as increased detection of CD45+ leukocytes, CD3+ T cells, IBA1+ phagocytes, and GFAP+ astrocytes, but a marked loss of occludin-positive tight junction staining, implying progressive endothelial activation/damage and cellular recruitment in inflamed brains. Orientia were sparse in the brains, but readily detectable within lectin+ vascular and IBA-1+ phagocytic cells. These CNS alterations were consistent with type 1-skewed, IL-13-suppressed responses in lethally-infected mouse lungs. SIGNIFICANCE This is the first report of type 1-skewed neuroinflammation and cellular activation, accompanied with vascular activation/damage, during OtK infection in C57BL/6 mice. This study not only enhances our understanding of the pathophysiological mechanisms of scrub typhus, but also correlates the impact of immune and vascular dysfunction on disease pathogenesis.
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Affiliation(s)
- Lynn Soong
- Department of Microbiology and Immunology, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail:
| | - Thomas R. Shelite
- Department of Microbiology and Immunology, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Internal Medicine/Division of Infectious Diseases, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Yan Xing
- Department of Microbiology and Immunology, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Pediatrics Department, People's Hospital of Henan Province, Zheng Zhou, Henan, China
| | - Harica Kodakandla
- School of Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Yuejin Liang
- Department of Microbiology and Immunology, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Brandon J. Trent
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Paulina Horton
- Department of Microbiology and Immunology, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Kathryn C. Smith
- Center in Environmental Toxicology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Zhenyang Zhao
- Department of Ophthalmology, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jiaren Sun
- Department of Microbiology and Immunology, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Donald H. Bouyer
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jiyang Cai
- Department of Ophthalmology, Institute of Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
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26
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Xu G, Mendell NL, Liang Y, Shelite TR, Goez-Rivillas Y, Soong L, Bouyer DH, Walker DH. CD8+ T cells provide immune protection against murine disseminated endotheliotropic Orientia tsutsugamushi infection. PLoS Negl Trop Dis 2017; 11:e0005763. [PMID: 28723951 PMCID: PMC5536391 DOI: 10.1371/journal.pntd.0005763] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 07/31/2017] [Accepted: 06/30/2017] [Indexed: 12/19/2022] Open
Abstract
Scrub typhus, caused by a Gram-negative obligately intracellular coccobacillus, Orientia tsutsugamushi, is a long neglected but important tropical disease. Orientia tsutsugamushi causes illness in one million people each year, and 1 billion people are at risk. Without appropriate diagnosis and treatment, the disease can cause severe multiorgan failure with a case fatality rate of 7–15%. The current gaps in knowledge of immunity include the unknown mechanisms of host immunity to O. tsutsugamushi. Using an intravenous (i.v.) disseminated infection mouse model, we observed that more CD8+ T cells than CD4+ T cells were present in the spleen of infected mice at 12 dpi. We also determined that Treg cells and the proportion of T cells producing IL-10 were significantly increased from 6 dpi, which correlated with the onset of illness, body weight loss, and increased bacterial loads. We further studied CD8-/-, MHC I-/- and wild type control (WT) C57BL/6J mice to determine the importance of CD8+ T cells and MHC I molecules. After infection with an ordinarily sub-lethal dose of O. tsutsugamushi, all CD8-/- and MHC I-/- mice were moribund between 12 and 15 dpi, whereas all WT mice survived. Bacterial loads in the lung, kidney, liver and spleen of CD8-/- and MHC I-/- mice were significantly greater than those in WT mice. Interferon-γ (IFN-γ) and granzyme B mRNA levels in the liver of CD8-/- and MHC I-/- mice were significantly greater than in WT mice. In addition, more severe histopathologic lesions were observed in CD8-/- mice. Finally, adoptive transfer confirmed a major role of immune CD8+ T cells as well as a less effective contribution by immune CD8 T cell-depleted splenocytes in protection against O. tsutsugamushi infection. These studies demonstrated the critical importance of CD8+ T cells in the host immune response during O. tsutsugamushi infection. Scrub typhus is a febrile illness that can be life-threatening without appropriate treatment. It is caused by a gram-negative, obligately intracellular bacterium, Orientia tsutsugamushi. Approximately one million people annually are infected globally, mainly in the Asia-Pacific area. Unfortunately, no vaccine has been developed for the prevention of the disease. There is very little known about the pathogenesis of or host immunity to scrub typhus. The limited number of studies on the mechanisms of immunity has failed to provide a fundamental explanation of the protective host immune response during the disease due in part to the outdated and inaccurate animal models employed. Here, we examined and confirmed that CD8+ T cells provide critical protection during the infection. Our data also demonstrated the potential contribution of non-CD8+ immune cells in protection against the infection. This study of host immune responses during scrub typhus with a more accurate mouse model improves the understanding of the interaction between the host and pathogen, and provides a foundation for future investigations of pathogenesis, immune control and prevention including vaccine development.
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Affiliation(s)
- Guang Xu
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Nicole L Mendell
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Yuejin Liang
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Thomas R Shelite
- Department of Internal Medicine, Division of Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Yenny Goez-Rivillas
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Lynn Soong
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America.,Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Donald H Bouyer
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - David H Walker
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America.,Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
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27
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Shen H, Lu Z, Xu Z, Shen Z. Diet-induced reconstruction of mucosal microbiota associated with alterations of epithelium lectin expression and regulation in the maintenance of rumen homeostasis. Sci Rep 2017. [PMID: 28638072 PMCID: PMC5479827 DOI: 10.1038/s41598-017-03478-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
It is unknown whether lectins of the rumen epithelium contribute to the recognition of mucosal microbes and activation of tolerogenic cytokines in ruminant animals. We applied an integrated method of RNA-seq and 16S rRNA gene sequencing to investigate alterations of epithelial lectin expression and regulation with a diet-induced reconstruction of the mucosal microbiota in the goat rumen. Our results showed that the diversity and richness of the rumen mucosal microbiota were promoted by the dietary concentrate. Meantime, in the rumen epithelium, five lectin genes, namely, sialic acid-binding Ig-like lectin 14 (LOC102180073), C-type lectin domain family 4, member E (CLEC4E), C-type lectin domain family 7, member A (CLEC7A), C-type lectin domain family 16, member A (CLEC16A), and lectin, mannose-binding 2 (LMAN2), were indicated to promote the expression of 8 tolerogenic cytokines, transforming growth factor beta 1 (TGFB1) and 4 enzyme genes involved in retinoic acid biosynthesis via 6 signaling pathways. Analysis of the combined data showed that 9 microbial genera (Clostridium_IV, Desulfobulbus, Eubacterium, Ochrobactrum, Propionibacterium, Pseudomonas, Slackia, Staphylococcus and Subdivision5_genera_IS) were highly related to the expression of functional lectins. These findings provide new insights into the interactions between the rumen epithelium and mucosal microbiota in the maintenance of rumen homeostasis.
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Affiliation(s)
- Hong Shen
- College of Life Science, Nanjing Agricultural University, Nanjing, Jiangsu, China.,Bioinformatics Center, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Zhongyan Lu
- Key Lab of Animal Physiology and Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.
| | - Zhihui Xu
- College of Life Science, Nanjing Agricultural University, Nanjing, Jiangsu, China.,Bioinformatics Center, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Zanming Shen
- Key Lab of Animal Physiology and Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
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28
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Emerging Roles of IL-33/ST2 Axis in Renal Diseases. Int J Mol Sci 2017; 18:ijms18040783. [PMID: 28387719 PMCID: PMC5412367 DOI: 10.3390/ijms18040783] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 03/29/2017] [Accepted: 04/05/2017] [Indexed: 12/16/2022] Open
Abstract
Renal diseases, including acute kidney injury (AKI) and chronic kidney disease (CKD), have a great impact on health care systems worldwide. Similar to cardiovascular diseases, renal diseases are inflammatory diseases involving a variety of cytokines. Primary causes of renal injury include ischemia, uremic toxins, bacteremia, or nephrotoxicity. Inflammation represents an important component following kidney injury. Interleukin (IL)-33 is a member of the IL-1 cytokine family, which is widely expressed in epithelial barrier tissues and endothelial cells, and mediates both tissue inflammation and repair responses. IL-33 is released as a nuclear alarmin in response to tissue damage and triggers innate and adaptive immune responses by binding to its receptor, suppression of tumorigenicity 2 (ST2). Recent evidence from clinical and experimental animal studies indicates that the IL-33/ST2 axis is involved in the pathogenesis of CKD, renal graft injury, systemic lupus nephritis, and AKI. In this review, we discuss the pathological and tissue reparative roles of the IL-33/ST2 pathway in different types of renal diseases.
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29
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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] [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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30
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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] [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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