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Jaroenlak P, McCarty KL, Xia B, Lam C, Zwack EE, Yanai I, Bhabha G, Ekiert DC. scRNA-seq reveals transcriptional dynamics of Encephalitozoon intestinalis parasites in human macrophages. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596468. [PMID: 38853846 PMCID: PMC11160751 DOI: 10.1101/2024.05.30.596468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Microsporidia are single-celled intracellular parasites that cause opportunistic diseases in humans. Encephalitozoon intestinalis is a prevalent human-infecting species that invades the small intestine. Dissemination to other organ systems is also observed, and is potentially facilitated by macrophages. The macrophage response to infection and the developmental trajectory of the parasite are not well studied. Here we use single cell RNA sequencing to investigate transcriptional changes in both the host and parasite during infection. While a small population of infected macrophages mount a response, most remain transcriptionally unchanged, suggesting that the majority of parasites may avoid host detection. The parasite transcriptome reveals large transcriptional changes throughout the life cycle, providing a blueprint for parasite development. The stealthy microsporidian lifestyle likely allows these parasites to harness macrophages for replication and dissemination. Together, our data provide insights into the host response in primary human macrophages and the E. intestinalis developmental program.
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Affiliation(s)
- Pattana Jaroenlak
- Department of Cell Biology, New York University Grossman School of Medicine, New York 10016, USA
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kacie L. McCarty
- Department of Cell Biology, New York University Grossman School of Medicine, New York 10016, USA
- Department of Microbiology, New York University Grossman School of Medicine, New York 10016, USA
| | - Bo Xia
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Cherry Lam
- Department of Cell Biology, New York University Grossman School of Medicine, New York 10016, USA
| | - Erin E. Zwack
- Department of Microbiology, New York University Grossman School of Medicine, New York 10016, USA
| | - Itai Yanai
- Institute for Computational Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Gira Bhabha
- Department of Cell Biology, New York University Grossman School of Medicine, New York 10016, USA
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Damian C. Ekiert
- Department of Cell Biology, New York University Grossman School of Medicine, New York 10016, USA
- Department of Microbiology, New York University Grossman School of Medicine, New York 10016, USA
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
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2
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Caravello G, Franchet A, Niehus S, Ferrandon D. Phagocytosis Is the Sole Arm of Drosophila melanogaster Known Host Defenses That Provides Some Protection Against Microsporidia Infection. Front Immunol 2022; 13:858360. [PMID: 35493511 PMCID: PMC9043853 DOI: 10.3389/fimmu.2022.858360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 03/18/2022] [Indexed: 11/13/2022] Open
Abstract
Microsporidia are obligate intracellular parasites able to infest specifically a large range of species, including insects. The knowledge about the biology of microsporidial infections remains confined to mostly descriptive studies, including molecular approaches such as transcriptomics or proteomics. Thus, functional data to understand insect host defenses are currently lacking. Here, we have undertaken a genetic analysis of known host defenses of the Drosophila melanogaster using an infection model whereby Tubulinosema ratisbonensis spores are directly injected in this insect. We find that phagocytosis does confer some protection in this infection model. In contrast, the systemic immune response, extracellular reactive oxygen species, thioester proteins, xenophagy, and intracellular antiviral response pathways do not appear to be involved in the resistance against this parasite. Unexpectedly, several genes such as PGRP-LE seem to promote this infection. The prophenol oxidases that mediate melanization have different functions; PPO1 presents a phenotype similar to that of PGRP-LE whereas that of PPO2 suggests a function in the resilience to infection. Similarly, eiger and Unpaired3, which encode two cytokines secreted by hemocytes display a resilience phenotype with a strong susceptibility to T. ratisbonensis.
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Affiliation(s)
| | | | | | - Dominique Ferrandon
- UPR9022, University of Strasbourg, Institut de Biologie Moléculaire et Cellulaire (IBMC), Modèles Insectes D’Immunité Innée (M3I) Unité Propre Recherche (UPR) 9022 du Centre National de la Recherche Scientifique (CNRS), Strasbourg, France
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3
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Abstract
Microsporidia are obligate intracellular pathogens identified ∼150 years ago as the cause of pébrine, an economically important infection in silkworms. There are about 220 genera and 1,700 species of microsporidia, which are classified based on their ultrastructural features, developmental cycle, host-parasite relationship, and molecular analysis. Phylogenetic analysis suggests that microsporidia are related to the fungi, being grouped with the Cryptomycota as a basal branch or sister group to the fungi. Microsporidia can be transmitted by food and water and are likely zoonotic, as they parasitize a wide range of invertebrate and vertebrate hosts. Infection in humans occurs in both immunocompetent and immunodeficient hosts, e.g., in patients with organ transplantation, patients with advanced human immunodeficiency virus (HIV) infection, and patients receiving immune modulatory therapy such as anti-tumor necrosis factor alpha antibody. Clusters of infections due to latent infection in transplanted organs have also been demonstrated. Gastrointestinal infection is the most common manifestation; however, microsporidia can infect virtually any organ system, and infection has resulted in keratitis, myositis, cholecystitis, sinusitis, and encephalitis. Both albendazole and fumagillin have efficacy for the treatment of various species of microsporidia; however, albendazole has limited efficacy for the treatment of Enterocytozoon bieneusi. In addition, immune restoration can lead to resolution of infection. While the prevalence rate of microsporidiosis in patients with AIDS has fallen in the United States, due to the widespread use of combination antiretroviral therapy (cART), infection continues to occur throughout the world and is still seen in the United States in the setting of cART if a low CD4 count persists.
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4
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Aseeja P, Shaikh Y, Bajpai A, Sirsikar P, Kalra SK. Advancement in our understanding of immune response against Encephalitozoon infection. Parasite Immunol 2021; 43:e12828. [PMID: 33682117 DOI: 10.1111/pim.12828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 01/15/2023]
Abstract
Microsporidia are a group of obligate, intracellular, spore-forming eukaryotic pathogens, which predominantly infects immunocompromised individuals worldwide. Encephalitozoon spp. is one of the most prevalent microsporidia known to infect humans. Host immune system plays a major role in combating pathogens including Encephalitozoon spp. infecting humans. Both innate and adaptive arms of host immune system work together in combating Encephalitozoon infection. Researchers are conducting studies to elucidate the role of both arms of immune system against Encephalitozoon infection. In addition to cell-mediated adaptive immunity, role of innate immunity is also being highlighted in clearance of Encephalitozoon spp. from host body. Therefore, the current review will give a clear and consolidated update on the role of innate as well as adaptive immunity in protection against Encephalitozoon spp.
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Affiliation(s)
- Praisy Aseeja
- Faculty of Applied Sciences & Biotechnology, Shoolini university of Biotechnology & Management Sciences, Solan, India
| | - Yasmin Shaikh
- Faculty of Applied Sciences & Biotechnology, Shoolini university of Biotechnology & Management Sciences, Solan, India
| | - Anamika Bajpai
- Centre for Translational Medicine, Lewis Katz School of Medicine, Medicine Education & Research Building, Temple University, Philadelphia, PA, USA
| | - Prachitee Sirsikar
- Faculty of Applied Sciences & Biotechnology, Shoolini university of Biotechnology & Management Sciences, Solan, India
| | - Sonali K Kalra
- Faculty of Applied Sciences & Biotechnology, Shoolini university of Biotechnology & Management Sciences, Solan, India
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5
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Tamim El Jarkass H, Reinke AW. The ins and outs of host-microsporidia interactions during invasion, proliferation and exit. Cell Microbiol 2020; 22:e13247. [PMID: 32748538 DOI: 10.1111/cmi.13247] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 12/12/2022]
Abstract
Microsporidia are a large group of fungal-related obligate intracellular parasites. They are responsible for infections in humans as well as in agriculturally and environmentally important animals. Although microsporidia are abundant in nature, many of the molecular mechanisms employed during infection have remained enigmatic. In this review, we highlight recent work showing how microsporidia invade, proliferate and exit from host cells. During invasion, microsporidia use spore wall and polar tube proteins to interact with host receptors and adhere to the host cell surface. In turn, the host has multiple defence mechanisms to prevent and eliminate these infections. Microsporidia encode numerous transporters and steal host nutrients to facilitate proliferation within host cells. They also encode many secreted proteins which may modulate host metabolism and inhibit host cell defence mechanisms. Spores exit the host in a non-lytic manner that is dependent on host actin and endocytic recycling proteins. Together, this work provides a fuller picture of the mechanisms that these fascinating organisms use to infect their hosts.
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Affiliation(s)
| | - Aaron W Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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Han Y, Gao H, Xu J, Luo J, Han B, Bao J, Pan G, Li T, Zhou Z. Innate and Adaptive Immune Responses Against Microsporidia Infection in Mammals. Front Microbiol 2020; 11:1468. [PMID: 32670257 PMCID: PMC7332555 DOI: 10.3389/fmicb.2020.01468] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 06/04/2020] [Indexed: 12/22/2022] Open
Abstract
Microsporidia are obligate intracellular and eukaryotic pathogens that can infect immunocompromised and immunocompetent mammals, including humans. Both innate and adaptive immune systems play important roles against microsporidian infection. The innate immune system can partially eliminate the infection by immune cells, such as gamma delta T cell, natural killer cells (NKs), macrophages and dendritic cells (DCs), and present the pathogens to lymphocytes. The innate immune cells can also prime and enhance the adaptive immune response via surface molecules and secreted cytokines. The adaptive immune system is critical to eliminate microsporidian infection by activating cytotoxic T lymphocyte (CTL) and humoral immune responses, and feedback regulation of the innate immune mechanism. In this review, we will discuss the cellular and molecular responses and functions of innate and adaptive immune systems against microsporidian infection.
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Affiliation(s)
- Yinze Han
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Hailong Gao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Jinzhi Xu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Jian Luo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Bing Han
- Department of Pathology, Albert Einstein College of Medicine, The Bronx, NY, United States
| | - Jialing Bao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Guoqing Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Tian Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Zeyang Zhou
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.,College of Life Sciences, Chongqing Normal University, Chongqing, China
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7
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González-Machorro JR, Rodríguez-Tovar LE, Gómez-Flores R, Soto-Dominguez A, Rodríguez-Rocha H, Garcia-García A, Tamez-Guerra P, Castillo-Velázquez U. Increased phagocytosis and growth inhibition of Encephalitozoon cuniculi by LPS-activated J774A.1 murine macrophages. Parasitol Res 2019; 118:1841-1848. [PMID: 31001676 DOI: 10.1007/s00436-019-06310-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 04/03/2019] [Indexed: 11/28/2022]
Abstract
Encephalitozoon cuniculi is an obligate macrophage parasite of vertebrates that commonly infects rodents, monkeys, dogs, birds, and humans. In the present study, we aimed to assess the phagocytosis and intracellular survival of E. cuniculi spores using untreated and lipopolysaccharide (LPS)-activated J774A.1 murine macrophages and assess the macrophage viability. The experimental groups comprised untreated spores, spores killed by heat treatment at 90 °C, and spores killed by treatment with 10% formalin. LPS-activated macrophages significantly increased the phagocytosis of spores and reduced their intracellular growth after 24 and 48 h (P < 0.01); however, after 72 h, we observed an increase in spore replication but no detectable microbicidal activity. These results indicate that LPS activation enhanced E. cuniculi phagocytosis between 24 and 48 h of treatment, but the effect was lost after 72 h, enabling parasitic growth. This study contributes to the understanding of the phagocytosis and survival of E. cuniculi in murine macrophages.
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Affiliation(s)
- J R González-Machorro
- Facultad de Medicina Veterinaria y Zootecnia, Departamento de Inmunología Veterinaria, Campus de Agricultura y Ciencias Biológicas, Universidad Autónoma de Nuevo León, Francisco Villa S/N, Colonia Ex-Hacienda el Canadá, CP 66050, Escobedo, Nuevo León, Mexico
| | - L E Rodríguez-Tovar
- Facultad de Medicina Veterinaria y Zootecnia, Departamento de Inmunología Veterinaria, Campus de Agricultura y Ciencias Biológicas, Universidad Autónoma de Nuevo León, Francisco Villa S/N, Colonia Ex-Hacienda el Canadá, CP 66050, Escobedo, Nuevo León, Mexico
| | - R Gómez-Flores
- Facultad de Ciencias Biológicas, Departamento de Microbiología e Inmunología, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, Mexico
| | - A Soto-Dominguez
- Facultad de Medicina, Departamento de Histología, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico
| | - H Rodríguez-Rocha
- Facultad de Medicina, Departamento de Histología, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico
| | - A Garcia-García
- Facultad de Medicina Veterinaria y Zootecnia, Departamento de Inmunología Veterinaria, Campus de Agricultura y Ciencias Biológicas, Universidad Autónoma de Nuevo León, Francisco Villa S/N, Colonia Ex-Hacienda el Canadá, CP 66050, Escobedo, Nuevo León, Mexico
| | - P Tamez-Guerra
- Facultad de Ciencias Biológicas, Departamento de Microbiología e Inmunología, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, Mexico
| | - U Castillo-Velázquez
- Facultad de Medicina Veterinaria y Zootecnia, Departamento de Inmunología Veterinaria, Campus de Agricultura y Ciencias Biológicas, Universidad Autónoma de Nuevo León, Francisco Villa S/N, Colonia Ex-Hacienda el Canadá, CP 66050, Escobedo, Nuevo León, Mexico.
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8
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Dreschers S, Saupp P, Hornef M, Prehn A, Platen C, Morschhäuser J, Orlikowsky TW. Reduced PICD in Monocytes Mounts Altered Neonate Immune Response to Candida albicans. PLoS One 2016; 11:e0166648. [PMID: 27870876 PMCID: PMC5117704 DOI: 10.1371/journal.pone.0166648] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 11/01/2016] [Indexed: 01/06/2023] Open
Abstract
Background Invasive fungal infections with Candida albicans (C. albicans) occur frequently in extremely low birthweight (ELBW) infants and are associated with poor outcome. Phagocytosis of C.albicans initializes apoptosis in monocytes (phagocytosis induced cell death, PICD). PICD is reduced in neonatal cord blood monocytes (CBMO). Hypothesis Phagocytosis of C. albicans causes PICD which differs between neonatal monocytes (CBMO) and adult peripheral blood monocytes (PBMO) due to lower stimulation of TLR-mediated immune responses. Methods The ability to phagocytose C. albicans, expression of TLRs, the induction of apoptosis (assessment of sub-G1 and nick-strand breaks) were analyzed by FACS. TLR signalling was induced by agonists such as lipopolysaccharide (LPS), Pam3Cys, FSL-1 and Zymosan and blocked (neutralizing TLR2 antibodies and MYD88 inhibitor). Results Phagocytic indices of PBMO and CBMO were similar. Following stimulation with agonists and C. albicans induced up-regulation of TLR2 and consecutive phosphorylation of MAP kinase P38 and expression of TNF-α, which were stronger on PBMO compared to CBMO (p < 0.005). Downstream, TLR2 signalling initiated caspase-3-dependent PICD which was found reduced in CBMO (p < 0.05 vs PBMO). Conclusion Our data suggest direct involvement of TLR2-signalling in C. albicans-induced PICD in monocytes and an alteration of this pathway in CBMO.
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Affiliation(s)
- Stephan Dreschers
- Department of Neonatology, University Children’s Hospital, Aachen, Germany
| | - Peter Saupp
- Department of Neonatology, University Children’s Hospital, Aachen, Germany
| | - Mathias Hornef
- Institute of Medical Microbiology, University Children’s Hospital, Aachen, Germany
| | - Andrea Prehn
- Department of Environmental Medicine, University Children’s Hospital, Aachen, Germany
| | - Christopher Platen
- Department of Neonatology, University Children’s Hospital, Aachen, Germany
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9
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Fang P, Shi HY, Wu XM, Zhang YH, Zhong YJ, Deng WJ, Zhang YP, Xie M. Targeted inhibition of GATA-6 attenuates airway inflammation and remodeling by regulating caveolin-1 through TLR2/MyD88/NF-κB in murine model of asthma. Mol Immunol 2016; 75:144-50. [PMID: 27289030 DOI: 10.1016/j.molimm.2016.05.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 05/20/2016] [Accepted: 05/23/2016] [Indexed: 12/11/2022]
Abstract
The purpose of this study was to evaluate the effects of GATA-6 on airway inflammation and remodeling and the underlying mechanisms in a murine model of chronic asthma. Female BALB/c mice were randomly divided into four groups: phosphate-buffered saline control (PBS), ovalbumin (OVA)-induced asthma group (OVA), OVA+ siNC and OVA+ siGATA-6. In this mice model, GATA-6 expression level was significantly elevated and the expression in Caveolin-1 (Cav-1) inversely correlated with the abundance of GATA-6 in OVA-induced asthma of mice. Silencing of GATA-6 gene expression upregulated Cav-1 expression. Additionally, downregulation of GATA-6 dramatically decreased OVA-challenged inflammation, infiltration, and mucus production. Moreover, silencing of GATA-6 resulted in decreased levels of immunoglobulin E (IgE) and inflammatory mediators and reduced inflammatory cell accumulation, as well as inhibiting the expression of important mediators including matrix metalloproteinase (MMP)-2 and MMP-9, TGF-β1, and a disintegrin and metalloproteinase 8 (ADAM8) and ADAM33, which is related to airway remodeling. Further analysis confirmed that silencing of GATA-6 attenuated OVA-induced airway inflammation and remodeling through the TLR2/MyD88 and NF-κB pathway. In conclusion, these findings indicated that the downregulation of GATA-6 effectively inhibited airway inflammation and reversed airway remodeling via Cav-1, at least in part through downregulation of TLR2/MyD88/NF-κB, which suggests that GATA-6 represents a promising therapeutic strategy for human allergic asthma.
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Affiliation(s)
- Ping Fang
- Respiratory Department, The Second Affiliated Hospital, Xi'an Jiaotong University School of Medicine, Xi'an 710004, Shaanxi, PR China.
| | - Hong-Yang Shi
- Respiratory Department, The Second Affiliated Hospital, Xi'an Jiaotong University School of Medicine, Xi'an 710004, Shaanxi, PR China
| | - Xiao-Ming Wu
- Key Laboratory, Biochemical Information Engineering of Ministry of Education Xi'an Jiaotong University School of Life Science and Technology, Xi'an 710049, Shaanxi, PR China
| | - Yong-Hong Zhang
- Respiratory Department, The Second Affiliated Hospital, Xi'an Jiaotong University School of Medicine, Xi'an 710004, Shaanxi, PR China
| | - Yu-Jie Zhong
- Respiratory Department, The Second Affiliated Hospital, Xi'an Jiaotong University School of Medicine, Xi'an 710004, Shaanxi, PR China
| | - Wen-Jing Deng
- Respiratory Department, The Second Affiliated Hospital, Xi'an Jiaotong University School of Medicine, Xi'an 710004, Shaanxi, PR China
| | - Yu-Ping Zhang
- Respiratory Department, The Second Affiliated Hospital, Xi'an Jiaotong University School of Medicine, Xi'an 710004, Shaanxi, PR China
| | - Mei Xie
- Respiratory Department, The Second Affiliated Hospital, Xi'an Jiaotong University School of Medicine, Xi'an 710004, Shaanxi, PR China
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10
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Tian Z, Yang L, Li P, Xiao Y, Peng J, Wang X, Li Z, Liu M, Bi D, Shi D. The inflammation regulation effects ofEnterococcus faeciumHDRsEf1 on human enterocyte-like HT-29 cells. Anim Cells Syst (Seoul) 2016. [DOI: 10.1080/19768354.2016.1160955] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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11
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Bernal CE, Zorro MM, Sierra J, Gilchrist K, Botero JH, Baena A, Ramirez-Pineda JR. Encephalitozoon intestinalis Inhibits Dendritic Cell Differentiation through an IL-6-Dependent Mechanism. Front Cell Infect Microbiol 2016; 6:4. [PMID: 26870700 PMCID: PMC4735406 DOI: 10.3389/fcimb.2016.00004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/12/2016] [Indexed: 01/03/2023] Open
Abstract
Microsporidia are a group of intracellular pathogens causing self-limited and severe diseases in immunocompetent and immunocompromised individuals, respectively. A cellular type 1 adaptive response, mediated by IL-12, IFNγ, CD4+, and CD8+ T cells has been shown to be essential for host resistance, and dendritic cells (DC) play a key role at eliciting anti-microsporidial immunity. We investigated the in vitro response of DC and DC precursors/progenitors to infection with Encephalitozoon intestinalis (Ei), a common agent of human microsporidosis. Ei-exposed DC cultures up-regulated the surface expression of MHC class II and the costimulatory molecules CD86 and CD40, only when high loads of spores were used. A vigorous secretion of IL-6 but not of IL-1β or IL-12p70 was also observed in these cultures. Ei-exposed DC cultures consisted of immature infected and mature bystander DC, as assessed by MHC class II and costimulatory molecules expression, suggesting that intracellular Ei spores deliver inhibitory signals in DC. Moreover, Ei selectively inhibited the secretion of IL-12p70 in LPS-stimulated DC. Whereas Ei-exposed DC promoted allogeneic naïve T cell proliferation and IL-2 and IFNγ secretion in DC-CD4+ T cell co-cultures, separated co-cultures with bystander or infected DCs showed stimulation or inhibition of IFNγ secretion, respectively. When DC precursors/progenitors were exposed to Ei spores, a significant inhibition of DC differentiation was observed without shifting the development toward cells phenotypically or functionally compatible with myeloid-derived suppressor cells. Neutralization experiments demonstrated that this inhibitory effect is IL-6-dependent. Altogether this investigation reveals a novel potential mechanism of immune escape of microsporidian parasites through the modulation of DC differentiation and maturation.
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Affiliation(s)
- Carmen E Bernal
- Grupo Inmunomodulación, Universidad de AntioquiaMedellín, Colombia; Grupo de Parasitología, Universidad de AntioquiaMedellín, Colombia
| | - Maria M Zorro
- Grupo Inmunomodulación, Universidad de Antioquia Medellín, Colombia
| | - Jelver Sierra
- Grupo Inmunomodulación, Universidad de Antioquia Medellín, Colombia
| | | | - Jorge H Botero
- Grupo de Parasitología, Universidad de Antioquia Medellín, Colombia
| | - Andres Baena
- Grupo de Inmunología Celular e Inmunogenética, Universidad de AntioquiaMedellín, Colombia; Departamento de Microbiología y Parasitología, Universidad de AntioquiaMedellín, Colombia
| | - Jose R Ramirez-Pineda
- Grupo Inmunomodulación, Universidad de AntioquiaMedellín, Colombia; Corporación Académica para el Estudio de Patologías Tropicales, Facultad de Medicina, Universidad de AntioquiaMedellín, Colombia
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12
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El-Khattouti A, Selimovic D, Hannig M, Taylor EB, Abd Elmageed ZY, Hassan SY, Haikel Y, Kandil E, Leverkus M, Brodell RT, Megahed M, Hassan M. Imiquimod-induced apoptosis of melanoma cells is mediated by ER stress-dependent Noxa induction and enhanced by NF-κB inhibition. J Cell Mol Med 2015; 20:266-86. [PMID: 26578344 PMCID: PMC4727561 DOI: 10.1111/jcmm.12718] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 09/15/2015] [Indexed: 12/21/2022] Open
Abstract
Melanoma is characterized by dysregulated intracellular signalling pathways including an impairment of the cell death machinery, ultimately resulting in melanoma resistance, survival and progression. This explains the tumour's extraordinary resistance to the standard treatment. Imiquimod is a topical immune response modifier (imidazoquinoline) with both antiviral and antitumour activities. The mechanism by which imiquimod triggers the apoptosis of melanoma cells has now been carefully elucidated. Imiquimod‐induced apoptosis is associated with the activation of apoptosis signalling regulating kinase1/c‐Jun‐N‐terminal kinase/p38 pathways and the induction of endoplasmic stress characterized by the activation of the protein kinase RNA‐like endoplasmic reticulum kinase signalling pathway, increase in intracellular Ca2+ release, degradation of calpain and subsequent cleavage of caspase‐4. Moreover, imiquimod triggers the activation of NF‐κB and the expression of the inhibitor of apoptosis proteins (IAPs) such as, X‐linked IAP (XIAP) together with the accumulation of reactive oxygen species (ROS). Also, imiquimod triggers mitochondrial dysregulation characterized by the loss of mitochondrial membrane potential (Δψm), the increase in cytochrome c release, and cleavage of caspase‐9, caspase‐3 and poly(ADP‐ribose) polymerase (PARP). Inhibitors of specific pathways, permit the elucidation of possible mechanisms of imiquimod‐induced apoptosis. They demonstrate that inhibition of NF‐kB by the inhibitor of nuclear factor kappa‐B kinase (IKK) inhibitor Bay 11‐782 or knockdown of XIAP induces melanoma apoptosis in cells exposed to imiquimod. These findings support the use of either IKK inhibitors or IAP antagonists as adjuvant therapies to improve the effectiveness topical imiquimod in the treatment of melanoma.
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Affiliation(s)
| | - Denis Selimovic
- Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, University Hospital of Saarland, Homburg/Saar, Germany
| | - Matthias Hannig
- Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, University Hospital of Saarland, Homburg/Saar, Germany
| | - Erin B Taylor
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA
| | | | - Sofie Y Hassan
- Clinic of Dermatology, University Hospital of Aachen, Aachen, Germany
| | - Youssef Haikel
- Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, Strasbourg, France.,Department of Operative Dentistry and Endodontics, Dental Faculty, University of Strasbourg, Strasbourg, France
| | - Emad Kandil
- Department of Surgery, Tulane University School of Medicine, New Orleans, LA, USA
| | - Martin Leverkus
- Clinic of Dermatology, University Hospital of Aachen, Aachen, Germany
| | - Robert T Brodell
- Department of Dermatology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Mosaad Megahed
- Clinic of Dermatology, University Hospital of Aachen, Aachen, Germany
| | - Mohamed Hassan
- Cancer Institute, University of Mississippi Medical Center, Jackson, MS, USA.,Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, University Hospital of Saarland, Homburg/Saar, Germany.,Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, Strasbourg, France.,Department of Pathology, University of Mississippi Medical Center, Jackson, MS, USA
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13
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Wang M, Wang F, Yang J, Zhao D, Wang H, Shao F, Wang W, Sun R, Ling M, Zhai J, Song S. Mannan-binding lectin inhibits Candida albicans-induced cellular responses in PMA-activated THP-1 cells through Toll-like receptor 2 and Toll-like receptor 4. PLoS One 2013; 8:e83517. [PMID: 24391778 PMCID: PMC3877063 DOI: 10.1371/journal.pone.0083517] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 11/04/2013] [Indexed: 11/29/2022] Open
Abstract
Background Candida albicans (C. albicans), the most common human fungal pathogen, can cause fatal systemic infections under certain circumstances. Mannan-binding lectin (MBL),a member of the collectin family in the C-type lectin superfamily, is an important serum component associated with innate immunity. Toll-like receptors (TLRs) are expressed extensively, and have been shown to be involved in C. albicans-induced cellular responses. We first examined whether MBL modulated heat-killed (HK) C. albicans-induced cellular responses in phorbol 12-myristate 13-acetate (PMA)-activated human THP-1 macrophages. We then investigated the possible mechanisms of its inhibitory effect. Methodology/Principal Finding Enzyme-linked immunosorbent assay (ELISA) and reverse transcriptasepolymerase chain reaction (RT-PCR) analysis showed that MBL at higher concentrations (10–20 µg/ml) significantly attenuated C. albicans-induced chemokine (e.g., IL-8) and proinflammatory cytokine (e.g., TNF-α) production from PMA-activated THP-1 cells at both protein and mRNA levels. Electrophoretic mobility shift assay (EMSA) and Western blot (WB) analysis showed that MBL could inhibit C. albicans-induced nuclear factor-κB (NF-κB) DNA binding and its translocation in PMA-activated THP-1 cells. MBL could directly bind to PMA-activated THP-1 cells in the presence of Ca2+, and this binding decreased TLR2 and TLR4 expressions in C. albicans-induced THP-1 macrophages. Furthermore, the binding could be partially inhibited by both anti-TLR2 monoclonal antibody (clone TL2.1) and anti-TLR4 monoclonal antibody (clone HTA125). In addition, co-immunoprecipitation experiments and microtiter wells assay showed that MBL could directly bind to the recombinant soluble form of extracellular TLR2 domain (sTLR2) and sTLR4. Conclusions/Significance Our study demonstrates that MBL can affect proinflammatory cytokine and chemokine expressions by modifying C. albicans-/TLR-signaling pathways. This study supports an important role for MBL on the regulation of C. albicans-induced cellular responses.
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Affiliation(s)
- Mingyong Wang
- Department of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
- * E-mail:
| | - Fanping Wang
- Department of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
| | - Jianbin Yang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Dongfang Zhao
- Department of Clinical Laboratory, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Hongpo Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Feng Shao
- Department of Clinical Laboratory, The Third Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Wenjun Wang
- Cancer Research Institute, Southern Medical University, Guangzhou, China
| | - Ruili Sun
- Department of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
| | - Mingzhi Ling
- Department of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
| | - Jingjing Zhai
- Department of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
| | - Shijun Song
- Department of Clinical Laboratory, The Third Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
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14
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Quanxin G, Lili Q, Tianxing W, Tingting X, Jinbo W. Immunomodulatory effects ofClostridium butyricumon human enterocyte-like HT-29 cells. Anim Cells Syst (Seoul) 2013. [DOI: 10.1080/19768354.2013.789075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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15
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Affiliation(s)
- Magali M. Moretto
- Department of Microbiology, Immunology and Tropical Medicine, George Washington University, Washington, D.C., United States of America
| | - Imtiaz A. Khan
- Department of Microbiology, Immunology and Tropical Medicine, George Washington University, Washington, D.C., United States of America
- * E-mail: (IAK); (LMW)
| | - Louis M. Weiss
- Departments of Medicine and Pathology, Albert Einstein College of Medicine, Bronx, New York, United States of America
- * E-mail: (IAK); (LMW)
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16
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References. Parasitology 2012. [DOI: 10.1002/9781119968986.refs] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Vidal-Dorsch DE, Bay SM, Mays MA, Greenstein DJ, Young D, Wolf JC, Pham D, Loguinov AV, Vulpe C. Using gene expression to assess the status of fish from anthropogenically influenced estuarine wetlands. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:69-77. [PMID: 21793489 DOI: 10.1021/es2011308] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The diverse mixture of contaminants frequently present in estuaries complicates their assessment by routine chemical or biological analyses. We investigated the use of gene expression to assess contaminant exposure and the condition of southern California estuarine fish. Liver gene expression, plasma estradiol concentrations, and gonad histopathology were used to study biological condition in longjaw mudsuckers (Gillichthys mirabilis). Metals, legacy organochlorine pesticides, PCBs, and contaminants of emerging concern were detected in sediments and whole fish. Overall gene expression patterns were characteristic to each of four sites investigated in this study. Differentially expressed genes belonged to several functional categories including xenobiotic metabolism, detoxification, disease, and stress responses. In general, plasma estradiol concentrations were similar among fish from all areas. Some fish gonads had pathologic changes (e.g., infection, inflammation) that could indicate weakened immune systems and chronic stress. The differential expression of some genes involved in stress responses correlated with the prevalence of histologic gonad lesions. This study indicates that gene expression is a promising tool for assessing the biological condition of fish exposed to environmental contaminants.
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Affiliation(s)
- Doris E Vidal-Dorsch
- Southern California Coastal Water Research Project, Costa Mesa, California, United States.
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18
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Ghosh K, Weiss LM. T cell response and persistence of the microsporidia. FEMS Microbiol Rev 2011; 36:748-60. [PMID: 22126330 DOI: 10.1111/j.1574-6976.2011.00318.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 10/28/2011] [Accepted: 11/08/2011] [Indexed: 11/28/2022] Open
Abstract
The microsporidia are a diverse phylum of obligate intracellular parasites related to the fungi that cause significant and sometimes life-threatening disease in immune-compromised hosts, such as AIDS and organ transplant patients. More recently, their role in causing pathology in immune-competent populations has also been appreciated. Interestingly, in several instances, the microsporidia have been shown to persist in their hosts long term, causing at opposite ends of the spectrum either an intractable chronic diarrhea and wasting in patients with advanced-stage AIDS or asymptomatic shedding of spores in healthy populations. Much remains to be studied regarding the immune response to these pathogens, but it seems clear that CD8+ T cells are essential in clearing infection. However, in the infection models examined thus far, the role for CD4+ T cells is unclear at best. Here, we discuss the possible reasons and ramifications of what may be a weak primary CD4+ T cell response against Encephalitozoon cuniculi. Given the central role of the CD4+ T cell in other models of adaptive immunity, a better appreciation of its role in responding to microsporidia may provide insight into the survival strategies of these pathogens, which allow them to persist in hosts of varied immune status.
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Affiliation(s)
- Kaya Ghosh
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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19
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Gao Q, Qi L, Wu T, Wang J. Clostridium butyricum activates TLR2-mediated MyD88-independent signaling pathway in HT-29 cells. Mol Cell Biochem 2011; 361:31-7. [PMID: 21956671 DOI: 10.1007/s11010-011-1084-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 09/16/2011] [Indexed: 12/13/2022]
Abstract
Oral administration of Clostridium butyricum as probiotic is increasingly gaining importance in the treatment of diarrhea and the improvement of animal performance. However, the mechanisms of host cell receptor recognition of C. butyricum and the downstream immune signaling pathways leading to these benefits remain unclear. The objective of this study was to analyze the mechanisms involved in C. butyricum induction of the toll-like receptor (TLR) signaling. Knockdown of myeloid differentiation primary response protein 88 (MyD88) expression using small interfering RNA in this manner did not affect C. butyricum-induced elevated levels of nuclear factor κB (NF-κB), interleukin-8 (IL-8), IL-6, and tumor necrosis factor alpha (TNF-α), suggesting a MyD88-independent route to TLR signaling transduction. However, a significant reduction in the levels of NF-κB, IL-8, IL-6, and TNF-α was evident in the absence of TLR2 expression, implying the need for TLR2 in C. butyricum recognition. Hence, C. butyricum activates TLR2-mediated MyD88-independent signaling pathway in human epithelial cells, which adds to our understanding of the molecular mechanisms of this probiotic action on gut epithelium.
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Affiliation(s)
- Quanxin Gao
- Key Laboratory for Molecular Design and Nutrition Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo, China
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20
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Abstract
Intracellular parasitism has arisen only a few times during the long ancestry of protozoan parasites including in diverse groups such as microsporidians, kinetoplastids, and apicomplexans. Strategies used to gain entry differ widely from injection (e.g. microsporidians), active penetration of the host cell (e.g. Toxoplasma), recruitment of lysosomes to a plasma membrane wound (e.g. Trypanosoma cruzi), to host cell-mediated phagocytosis (e.g. Leishmania). The resulting range of intracellular niches is equally diverse ranging from cytosolic (e.g. T. cruzi) to residing within a non-fusigenic vacuole (e.g. Toxoplasma, Encephalitozoon) or a modified phagolysosome (e.g. Leishmania). These lifestyle choices influence access to nutrients, interaction with host cell signaling pathways, and detection by pathogen recognition systems. As such, intracellular life requires a repertoire of adaptations to assure entry-exit from the cell, as well as to thwart innate immune mechanisms and prevent clearance. Elucidating these pathways at the cellular and molecular level may identify key steps that can be targeted to reduce parasite survival or augment immunologic responses and thereby prevent disease.
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Affiliation(s)
- L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63100, USA.
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21
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Plasmacytoid DC from aged mice down-regulate CD8 T cell responses by inhibiting cDC maturation after Encephalitozoon cuniculi infection. PLoS One 2011; 6:e20838. [PMID: 21695169 PMCID: PMC3112225 DOI: 10.1371/journal.pone.0020838] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 05/12/2011] [Indexed: 01/21/2023] Open
Abstract
Age associated impairment of immune function results in inefficient vaccination, tumor surveillance and increased severity of infections. Several alterations in adaptive immunity have been observed and recent studies report age related declines in innate immune responses to opportunistic pathogens including Encephalitozoon cuniculi. We previously demonstrated that conventional dendritic cells (cDC) from 9-month-old animals exhibit sub-optimal response to E. cuniculi infection, suggesting that age associated immune senescence begins earlier than expected. We focused this study on how age affects plasmacytoid DC (pDC) function. More specifically how aged pDC affect cDC function as we observed that the latter are the predominant activators of CD8 T cells during this infection. Our present study demonstrates that pDC from middle-aged mice (12 months) suppress young (8 week old) cDC driven CD8 T cell priming against E. cuniculi infection. The suppressive effect of pDC from older mice decreased maturation of young cDC via cell contact. Aged mouse pDC exhibited higher expression of PD-L1 and blockade of their interaction with cDC via this molecule restored cDC maturation and T cell priming. Furthermore, the PD-L1 dependent suppression of cDC T cell priming was restricted to effector function of antigen-specific CD8 T cells not their expansion. To the best of our knowledge, the data presented here is the first report highlighting a cell contact dependent, PD-L1 regulated, age associated defect in a DC subpopulation that results in a sub-optimal immune response against E. cuniculi infection. These results have broad implications for design of immunotherapeutic approaches to enhance immunity for aging populations.
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Texier C, Vidau C, Viguès B, El Alaoui H, Delbac F. Microsporidia: a model for minimal parasite–host interactions. Curr Opin Microbiol 2010; 13:443-9. [DOI: 10.1016/j.mib.2010.05.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 05/04/2010] [Accepted: 05/06/2010] [Indexed: 12/21/2022]
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23
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Optimal CD8 T-cell response against Encephalitozoon cuniculi is mediated by Toll-like receptor 4 upregulation by dendritic cells. Infect Immun 2010; 78:3097-102. [PMID: 20421379 DOI: 10.1128/iai.00181-10] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CD8+ T-cell immunity has been shown to play an important role in the protective immune response against Encephalitozoon cuniculi. Although earlier studies suggest that dendritic cells (DC) are important for the induction of this response, the factors responsible for initiation of the dendritic cell response against this pathogen have not been evaluated. In the current study, we demonstrate that E. cuniculi infection causes strong Toll-like receptor 4 (TLR4)-dependent dendritic cell activation and a blockade of this molecule reduces the ability of DC to prime an antigen-specific CD8+ T-cell response. Pretreatment of DC with anti-TLR4 antibody causes a defect in both in vitro and in vivo CD8+ T-cell priming. These findings, for the first time, emphasize the contribution of TLR4 in the induction of CD8+ T-cell immunity against E. cuniculi infection.
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Lee IT, Lee CW, Tung WH, Wang SW, Lin CC, Shu JC, Yang CM. Cooperation of TLR2 with MyD88, PI3K, and Rac1 in lipoteichoic acid-induced cPLA2/COX-2-dependent airway inflammatory responses. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 176:1671-84. [PMID: 20167866 DOI: 10.2353/ajpath.2010.090714] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Lipoteichoic acid (LTA) plays a role in the pathogenesis of severe inflammatory responses induced by Gram-positive bacterial infection. Cytosolic phospholipase A(2) (cPLA(2)), cyclooxygenase-2 (COX-2), prostaglandin E(2) (PGE(2)), and interleukin (IL)-6 have been demonstrated to engage in airway inflammation. In this study, LTA-induced cPLA(2) and COX-2 expression and PGE(2) or IL-6 synthesis were attenuated by transfection with siRNAs of TLR2, MyD88, Akt, p42, p38, JNK2, and p65 or pretreatment with the inhibitors of PI3K (LY294002), p38 (SB202190), MEK1/2 (U0126), JNK1/2 (SP600125), and NF-kappaB (helenalin) in human tracheal smooth muscle cells (HTSMCs). LTA also induced cPLA(2) and COX-2 expression and leukocyte count in bronchoalveolar lavage fluid in mice. LTA-regulated PGE(2) or IL-6 production was inhibited by pretreatment with the inhibitors of cPLA(2) (AACOCF(3)) and COX-2 (NS-398) or transfection with cPLA(2) siRNA or COX-2 siRNA, respectively. LTA-stimulated NF-kappaB translocation or cPLA(2) phosphorylation was attenuated by pretreatment with LY294002, SB202190, U0126, or SP600125. Furthermore, LTA could stimulate TLR2, MyD88, PI3K, and Rac1 complex formation. We also demonstrated that Staphylococcus aureus could trigger these responses through a similar signaling cascade in HTSMCs. It was found that PGE(2) could directly stimulate IL-6 production in HTSMCs or leukocyte count in bronchoalveolar lavage fluid in mice. These results demonstrate that LTA-induced MAPKs activation is mediated through the TLR2/MyD88/PI3K/Rac1/Akt pathway, which in turn initiates the activation of NF-kappaB, and ultimately induces cPLA(2)/COX-2-dependent PGE(2) and IL-6 generation.
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Affiliation(s)
- I-Ta Lee
- Department of Pharmacology, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan
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25
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Mathews A, Hotard A, Hale-Donze H. Innate immune responses to Encephalitozoon species infections. Microbes Infect 2009; 11:905-11. [PMID: 19573618 DOI: 10.1016/j.micinf.2009.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Accepted: 06/23/2009] [Indexed: 11/29/2022]
Abstract
Microsporidia are obligate intracellular, eukaryotic fungi, which have gained recognition as opportunistic parasites in immunocompromised patients. Resistance to lethal microsporidia infections requires a Th1 immune response; how this protection is initiated against Encephalitozoon species is the focus of this review article.
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Affiliation(s)
- Amber Mathews
- Department of Biological Sciences, Louisiana State University, 202 Life Sciences, Baton Rouge, LA 70803-1715, USA
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