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Guth C, Schumacher PP, Vijayakumar A, Borgmann H, Balles H, Koschel M, Risch F, Lenz B, Hoerauf A, Hübner MP, Ajendra J. Eosinophils Are an Endogenous Source of Interleukin-4 during Filarial Infections and Contribute to the Development of an Optimal T Helper 2 Response. J Innate Immun 2024; 16:159-172. [PMID: 38354709 PMCID: PMC10932553 DOI: 10.1159/000536357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/16/2024] [Indexed: 02/16/2024] Open
Abstract
INTRODUCTION Interleukin-4 (IL-4) is a central regulator of type 2 immunity, crucial for the defense against multicellular parasites like helminths. This study focuses on its roles and cellular sources during Litomosoides sigmodontis infection, a model for human filarial infections. METHODS Utilizing an IL-4 secretion assay, investigation into the sources of IL-4 during the progression of L. sigmodontis infection was conducted. The impact of eosinophils on the Th2 response was investigated through experiments involving dblGATA mice, which lack eosinophils and, consequently, eosinophil-derived IL-4. RESULTS The absence of eosinophils notably influenced Th2 polarization, leading to impaired production of type 2 cytokines. Interestingly, despite this eosinophil deficiency, macrophage polarization, proliferation, and antibody production remained unaffected. CONCLUSION Our research uncovers eosinophils as a major source of IL-4, especially during the early phase of filarial infection. Consequently, these findings shed new light on IL-4 dynamics and eosinophil effector functions in filarial infections.
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Affiliation(s)
- Cécile Guth
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Pia Philippa Schumacher
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Archena Vijayakumar
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Hannah Borgmann
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Helene Balles
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Marianne Koschel
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Frederic Risch
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Benjamin Lenz
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Marc P. Hübner
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Jesuthas Ajendra
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
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Linnemann LC, Reitz M, Feyerabend TB, Breloer M, Hartmann W. Limited role of mast cells during infection with the parasitic nematode Litomosoides sigmodontis. PLoS Negl Trop Dis 2020; 14:e0008534. [PMID: 32735561 PMCID: PMC7423137 DOI: 10.1371/journal.pntd.0008534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 08/12/2020] [Accepted: 06/29/2020] [Indexed: 12/26/2022] Open
Abstract
Mast cells are innate effector cells that due to their localization in the tissue form the first line of defense against parasites. We have previously shown that specifically mucosal mast cells were essential for the termination of the intestinal Strongyloides ratti infection. Here, we analyze the impact of mast cells on the immune response and defense against the tissue-dwelling filarial nematode Litomosoides sigmodontis using mast cell-deficient Cpa3cre mice. Despite an increase and an activation of mast cells at the site of infection in wildtype BALB/c mice the outcome of L. sigmodontis infection was not changed in mast cell-deficient BALB/c Cpa3cre mice. In Cpa3cre mice neither vascular permeability induced by blood-sucking mites nor the migration of L3 was altered compared to Cpa3 wildtype littermates. Worm burden in the thoracic cavity was alike in the presence and absence of mast cells during the entire course of infection. Although microfilaremiae in the peripheral blood increased in mast cell-deficient mice at some time points, the infection was cleared with comparable kinetics in the presence and absence of mast cells. Moreover, mast cell deficiency had no impact on the cytokine and antibody response to L. sigmodontis. In summary, our findings suggest that mast cells are not mandatory for the initiation of an appropriate immune response and host defense during L. sigmodontis infection in mice. Mast cells are innate cells that are equipped with biologically potent granule proteins. Due to their localization in many tissues they form the first line of defense against parasites such as helminths. In the current study we analyzed the impact of mast cell deficiency on the course of a tissue-dwelling helminth infection. Mice were infected with the filarial nematode L. sigmodontis in the presence and absence of mast cells. We show that mast cell numbers increase at the site of infection and that mast cells are activated. Despite the recruitment of mast cells in infected wildtype BALB/c mice, worm burden in the thoracic cavity and final eradication of microfilariae from the peripheral blood were alike in mast cell-deficient and wildtype mice. Mast cell deficiency had no impact on the anti-helminth immune response. In summary, our findings suggest that mast cells are not required for a protective immune response against L. sigmodontis infection in mice.
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Affiliation(s)
| | - Martina Reitz
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | - Minka Breloer
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Department of Biology, University of Hamburg, Hamburg, Germany
| | - Wiebke Hartmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- * E-mail:
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Frohberger SJ, Fercoq F, Neumann AL, Surendar J, Stamminger W, Ehrens A, Karunakaran I, Remion E, Vogl T, Hoerauf A, Martin C, Hübner MP. S100A8/S100A9 deficiency increases neutrophil activation and protective immune responses against invading infective L3 larvae of the filarial nematode Litomosoides sigmodontis. PLoS Negl Trop Dis 2020; 14:e0008119. [PMID: 32107497 PMCID: PMC7064255 DOI: 10.1371/journal.pntd.0008119] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 03/10/2020] [Accepted: 02/05/2020] [Indexed: 12/17/2022] Open
Abstract
Neutrophils are essentially involved in protective immune responses against invading infective larvae of filarial nematodes. The present study investigated the impact of S100A8/S100A9 on protective immune responses against the rodent filarial nematode Litomosoides sigmodontis. S100A9 forms with S100A8 the heterodimer calprotectin, which is expressed by circulating neutrophils and monocytes and mitigates or amplifies tissue damage as well as inflammation depending on the immune environment. Mice deficient for S100A8/A9 had a significantly reduced worm burden in comparison to wildtype (WT) animals 12 days after infection (dpi) with infective L3 larvae, either by the vector or subcutaneous inoculation, the latter suggesting that circumventing natural immune responses within the epidermis and dermis do not alter the phenotype. Nevertheless, upon intradermal injection of L3 larvae, increased total numbers of neutrophils, eosinophils and macrophages were observed within the skin of S100A8/A9-/- mice. Furthermore, upon infection the bronchoalveolar and thoracic cavity lavage of S100A8/A9-/- mice showed increased concentrations of CXCL-1, CXCL-2, CXCL-5, as well as elastase in comparison to the WT controls. Neutrophils from S100A8/A9-/- mice exhibited an increased in vitro activation and reduced L3 larval motility more effectively in vitro compared to WT neutrophils. The depletion of neutrophils from S100A8/A9-/- mice prior to L. sigmodontis infection until 5dpi abrogated the protective effect and led to an increased worm burden, indicating that neutrophils mediate enhanced protective immune responses against invading L3 larvae in S100A8/A9-/- mice. Interestingly, complete circumvention of protective immune responses in the skin and the lymphatics by intravenous injection of L3 larvae reversed the phenotype and resulted in an increased worm burden in S100A8/A9-/- mice. In summary, our results reveal that lack of S100A8/S100A9 triggers L3-induced inflammatory responses, increasing chemokine levels, granulocyte recruitment as well as neutrophil activation and therefore impairs larval migration and susceptibility for filarial infection.
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Affiliation(s)
- Stefan J. Frohberger
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Frederic Fercoq
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Muséum national d’Histoire naturelle, CNRS; Paris, France
| | - Anna-Lena Neumann
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Jayagopi Surendar
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Wiebke Stamminger
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Alexandra Ehrens
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Indulekha Karunakaran
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Estelle Remion
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Muséum national d’Histoire naturelle, CNRS; Paris, France
| | - Thomas Vogl
- Institute of Immunology, University Hospital of Münster, Münster, Germany
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Coralie Martin
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Muséum national d’Histoire naturelle, CNRS; Paris, France
| | - Marc P. Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- * E-mail:
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Card C, Wilson DS, Hirosue S, Rincon-Restrepo M, de Titta A, Güç E, Martin C, Bain O, Swartz MA, Kilarski WW. Adjuvant-free immunization with infective filarial larvae as lymphatic homing antigen carriers. Sci Rep 2020; 10:1055. [PMID: 31974398 PMCID: PMC6978462 DOI: 10.1038/s41598-020-57995-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 01/09/2020] [Indexed: 11/25/2022] Open
Abstract
Controlled infection with intestinal nematodes has therapeutic potential for preventing the symptoms of allergic and autoimmune diseases. Here, we engineered larvae of the filarial nematode Litomosoides sigmodontis as a vaccine strategy to induce adaptive immunity against a foreign, crosslinked protein, chicken egg ovalbumin (OVA), in the absence of an external adjuvant. The acylation of filarial proteins with fluorescent probes or biotin was not immediately detrimental to larval movement and survival, which died 3 to 5 days later. At least some of the labeled and skin-inoculated filariae migrated through lymphatic vessels to draining lymph nodes. The immunization potential of OVA-biotin-filariae was compared to that of an OVA-bound nanoparticulate carrier co-delivered with a CpG adjuvant in a typical vaccination scheme. Production of IFNγ and TNFα by restimulated CD4+ cells but not CD8+ confirmed the specific ability of filariae to stimulate CD4+ T cells. This alternative method of immunization exploits the intrinsic adjuvancy of the attenuated nematode carrier and has the potential to shift the vaccination immune response towards cellular immunity.
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Affiliation(s)
- Catherine Card
- Institute of Bioengineering and Swiss Institute for Experimental Cancer Research (ISREC), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - David S Wilson
- Institute for Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Sachiko Hirosue
- Institute of Bioengineering and Swiss Institute for Experimental Cancer Research (ISREC), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Marcela Rincon-Restrepo
- Institute of Bioengineering and Swiss Institute for Experimental Cancer Research (ISREC), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Alexandre de Titta
- Institute of Bioengineering and Swiss Institute for Experimental Cancer Research (ISREC), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Esra Güç
- Institute of Bioengineering and Swiss Institute for Experimental Cancer Research (ISREC), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Coralie Martin
- UMR7245, MCAM, Museum National d'Histoire Naturelle, Paris, France
| | - Odile Bain
- UMR7245, MCAM, Museum National d'Histoire Naturelle, Paris, France
| | - Melody A Swartz
- Institute of Bioengineering and Swiss Institute for Experimental Cancer Research (ISREC), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute for Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Witold W Kilarski
- Institute of Bioengineering and Swiss Institute for Experimental Cancer Research (ISREC), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
- Institute for Molecular Engineering, University of Chicago, Chicago, IL, USA.
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Knipper JA, Ivens A, Taylor MD. Helminth-induced Th2 cell dysfunction is distinct from exhaustion and is maintained in the absence of antigen. PLoS Negl Trop Dis 2019; 13:e0007908. [PMID: 31815932 PMCID: PMC6922449 DOI: 10.1371/journal.pntd.0007908] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 12/19/2019] [Accepted: 11/06/2019] [Indexed: 12/29/2022] Open
Abstract
T cell-intrinsic regulation, such as anergy, adaptive tolerance and exhaustion, is central to immune regulation. In contrast to Type 1 and Type 17 settings, knowledge of the intrinsic fate and function of Th2 cells in chronic Type 2 immune responses is lacking. We previously showed that Th2 cells develop a PD-1/PD-L2-dependent intrinsically hypo-responsive phenotype during infection with the filarial nematode Litomosoides sigmodontis, denoted by impaired functionality and parasite killing. This study aimed to elucidate the transcriptional changes underlying Th2 cell-intrinsic hypo-responsiveness, and whether it represents a unique and stable state of Th2 cell differentiation. We demonstrated that intrinsically hypo-responsive Th2 cells isolated from L. sigmodontis infected mice stably retained their dysfunctional Th2 phenotype upon transfer to naïve recipients, and had a divergent transcriptional profile to classical Th2 cells isolated prior to hypo-responsiveness and from mice exposed to acute Type 2 stimuli. Hypo-responsive Th2 cells displayed a distinct transcriptional profile to exhausted CD4+ T cells, but upregulated Blimp-1 and the anergy/regulatory-associated transcription factors Egr2 and c-Maf, and shared characteristics with tolerised T cells. Hypo-responsive Th2 cells increased mRNA expression of the soluble regulatory factors Fgl2, Cd38, Spp1, Areg, Metrnl, Lgals3, and Csf1, and a subset developed a T-bet+IFN-γ+ Th2/Th1 hybrid phenotype, indicating that they were not functionally inert. Contrasting with their lost ability to produce Th2 cytokines, hypo-responsive Th2 cells gained IL-21 production and IL-21R blockade enhanced resistance to L. sigmodontis. IL-21R blockade also increased the proportion of CD19+PNA+ germinal centre B cells and serum levels of parasite specific IgG1. This indicates a novel regulatory role for IL-21 during filarial infection, both in controlling protection and B cell responses. Thus, Th2 cell-intrinsic hypo-responsiveness is a distinct and stable state of Th2 cell differentiation associated with a switch from a classically active IL-4+IL-5+ Th2 phenotype, to a non-classical dysfunctional and potentially regulatory IL-21+Egr2+c-Maf+Blimp-1+IL-4loIL-5loT-bet+IFN-γ+ Th2 phenotype. This divergence towards alternate Th2 phenotypes during chronicity has broad implications for the outcomes and treatment of chronic Type 2-related infections and diseases.
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Affiliation(s)
- Johanna A. Knipper
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Alasdair Ivens
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Matthew D. Taylor
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Fercoq F, Remion E, Frohberger SJ, Vallarino-Lhermitte N, Hoerauf A, Le Quesne J, Landmann F, Hübner MP, Carlin LM, Martin C. IL-4 receptor dependent expansion of lung CD169+ macrophages in microfilaria-driven inflammation. PLoS Negl Trop Dis 2019; 13:e0007691. [PMID: 31469835 PMCID: PMC6742411 DOI: 10.1371/journal.pntd.0007691] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 09/12/2019] [Accepted: 08/06/2019] [Indexed: 11/19/2022] Open
Abstract
Lung disease is regularly reported in human filarial infections but the molecular pathogenesis of pulmonary filariasis is poorly understood. We used Litomosoides sigmodontis, a rodent filaria residing in the pleural cavity responsible for pleural inflammation, to model responses to human filarial infections and probe the mechanisms. Wild-type and Th2-deficient mice (ΔdblGata1 and Il-4receptor(r)a-/-/IL-5-/-) were infected with L. sigmodontis. Survival and growth of adult filariae and prevalence and density of microfilariae were evaluated. Cells and cytokines in the pleural cavity and bronchoalveolar space were characterized by imaging, flow cytometry and ELISA. Inflammatory pathways were evaluated by transcriptomic microarrays and lungs were isolated and analyzed for histopathological signatures. 40% of WT mice were amicrofilaremic whereas almost all mutant mice display blood microfilaremia. Microfilariae induced pleural, bronchoalveolar and lung-tissue inflammation associated with an increase in bronchoalveolar eosinophils and perivascular macrophages, production of mucus, visceral pleura alterations and fibrosis. Inflammation and pathology were decreased in Th2-deficient mice. An IL-4R-dependent increase of CD169 was observed on pleural and bronchoalveolar macrophages in microfilaremic mice. CD169+ tissue-resident macrophages were identified in the lungs with specific localizations. Strikingly, CD169+ macrophages increased significantly in the perivascular area in microfilaremic mice. These data describe lung inflammation and pathology in chronic filariasis and emphasize the role of Th2 responses according to the presence of microfilariae. It is also the first report implicating CD169+ lung macrophages in response to a Nematode infection.
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Affiliation(s)
- Frédéric Fercoq
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Université, Muséum national d’Histoire naturelle, CNRS; CP52, Paris, France
| | - Estelle Remion
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Université, Muséum national d’Histoire naturelle, CNRS; CP52, Paris, France
| | - Stefan J. Frohberger
- Institute for Medical Microbiology, Immunology & Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Nathaly Vallarino-Lhermitte
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Université, Muséum national d’Histoire naturelle, CNRS; CP52, Paris, France
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology & Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - John Le Quesne
- Leicester Cancer Research Centre, University of Leicester, Leicester, United Kingdom
| | | | - Marc P. Hübner
- Institute for Medical Microbiology, Immunology & Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Leo M. Carlin
- CRUK Beatson Institute, Garscube Estate, Bearsden, Glasgow, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Coralie Martin
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Université, Muséum national d’Histoire naturelle, CNRS; CP52, Paris, France
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Abstract
Filarial infections are characteristically chronic and can cause debilitating diseases governed by parasite-induced innate and adaptive immune responses. Filarial parasites traverse or establish niches in the skin (migrating infective larvae), in nonmucosal tissues (adult parasite niche) and in the blood or skin (circulating microfilariae) where they intersect with the host immune response. While several studies have demonstrated that filarial parasites and their antigens can modulate myeloid cells (monocyte, macrophage and dendritic cell subsets), T- and B-lymphocytes and skin resident cell populations, the role of innate lymphoid cells during filarial infections has only recently emerged. Despite the identification and characterization of innate lymphoid cells (ILCs) in murine helminth infections, little is actually known about the role of human ILCs during parasitic infections. The focus of this review will be to highlight the composition of ILCs in the skin, lymphatics and blood; where the host-parasite interaction is well-defined and to examine the role of ILCs during filarial infections.
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Affiliation(s)
- S Bonne-Année
- Laboratory of Parasitic Diseases, Helminth Immunology Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - T B Nutman
- Laboratory of Parasitic Diseases, Helminth Immunology Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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Karadjian G, Fercoq F, Pionnier N, Vallarino-Lhermitte N, Lefoulon E, Nieguitsila A, Specht S, Carlin LM, Martin C. Migratory phase of Litomosoides sigmodontis filarial infective larvae is associated with pathology and transient increase of S100A9 expressing neutrophils in the lung. PLoS Negl Trop Dis 2017; 11:e0005596. [PMID: 28486498 PMCID: PMC5438187 DOI: 10.1371/journal.pntd.0005596] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 05/19/2017] [Accepted: 04/25/2017] [Indexed: 01/22/2023] Open
Abstract
Filarial infections are tropical diseases caused by nematodes of the Onchocercidae family such as Mansonella perstans. The infective larvae (L3) are transmitted into the skin of vertebrate hosts by blood-feeding vectors. Many filarial species settle in the serous cavities including M. perstans in humans and L. sigmodontis, a well-established model of filariasis in mice. L. sigmodontis L3 migrate to the pleural cavity where they moult into L4 around day 9 and into male and female adult worms around day 30. Little is known of the early phase of the parasite life cycle, after the L3 is inoculated in the dermis by the vector and enters the afferent lymphatic vessels and before the moulting processes in the pleural cavity. Here we reveal a pulmonary phase associated with lung damage characterized by haemorrhages and granulomas suggesting L3 reach the lung via pulmonary capillaries and damage the endothelium and parenchyma by crossing them to enter the pleural cavity. This study also provides evidence for a transient inflammation in the lung characterized by a very early recruitment of neutrophils associated with high expression levels of S100A8 and S100A9 proteins. Mansonella perstans is a widespread human filarial parasite in Africa responsible for pleural and peritoneal cavity filariasis. Compared to other filarial parasites such as Wuchereria bancrofti, Brugia malayi, and Loa loa, the biology of M. perstans is poorly known. The blood-feeding vectors inject infective larvae (L3) into the host skin during a blood meal. Depending on the species, the L3 will then migrate to its specific site. In the murine model of filariasis Litomosoides sigmodontis L3 also reach the pleural cavity where they moult twice then mate and produce microfilariae. Migration patterns from the skin to the pleural cavity are partially known and involve a lymphatic phase. Here we present a sequential analysis of L3 infection from their inoculation to day 8 when they are settled in the pleural cavity, revealing the presence of L3 in the lung. Pulmonary damage including haemorrhages and granulomas is also observed suggesting that L3 could migrate to the pulmonary circulation and capillaries from where they could exit the lung to reach the pleural cavity. This induces a local inflammatory response characterized by neutrophil activation and upregulation.
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Affiliation(s)
- Gregory Karadjian
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum national d’Histoire naturelle, CNRS, Paris, France
| | - Frédéric Fercoq
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum national d’Histoire naturelle, CNRS, Paris, France
| | - Nicolas Pionnier
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum national d’Histoire naturelle, CNRS, Paris, France
| | - Nathaly Vallarino-Lhermitte
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum national d’Histoire naturelle, CNRS, Paris, France
| | - Emilie Lefoulon
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum national d’Histoire naturelle, CNRS, Paris, France
| | - Adélaïde Nieguitsila
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum national d’Histoire naturelle, CNRS, Paris, France
| | - Sabine Specht
- Institute for Medical Microbiology, Immunology & Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Leo M. Carlin
- Inflammation, Repair and Development, National Heart & Lung Institute, Imperial College London, London, United Kingdom
| | - Coralie Martin
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum national d’Histoire naturelle, CNRS, Paris, France
- * E-mail:
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Dietze KK, Dittmer U, Koudaimi DK, Schimmer S, Reitz M, Breloer M, Hartmann W. Filariae-Retrovirus Co-infection in Mice is Associated with Suppressed Virus-Specific IgG Immune Response and Higher Viral Loads. PLoS Negl Trop Dis 2016; 10:e0005170. [PMID: 27923052 PMCID: PMC5140070 DOI: 10.1371/journal.pntd.0005170] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 11/07/2016] [Indexed: 12/22/2022] Open
Abstract
Worldwide more than 2 billion people are infected with helminths, predominantly in developing countries. Co-infections with viruses such as human immunodeficiency virus (HIV) are common due to the geographical overlap of these pathogens. Helminth and viral infections induce antagonistic cytokine responses in their hosts. Helminths shift the immune system to a type 2-dominated immune response, while viral infections skew the cytokine response towards a type 1 immune response. Moreover, chronic helminth infections are often associated with a generalized suppression of the immune system leading to prolonged parasite survival, and also to a reduced defence against unrelated pathogens. To test whether helminths affect the outcome of a viral infection we set up a filarial/retrovirus co-infection model in C57BL/6 mice. Although Friend virus (FV) infection altered the L. sigmodontis-specific immunoglobulin response towards a type I associated IgG2 isotype in co-infected mice, control of L. sigmodontis infection was not affected by a FV-superinfection. However, reciprocal control of FV infection was clearly impaired by concurrent L. sigmodontis infection. Spleen weight as an indicator of pathology and viral loads in spleen, lymph nodes (LN) and bone marrow (BM) were increased in L. sigmodontis/FV-co-infected mice compared to only FV-infected mice. Numbers of FV-specific CD8+ T cells as well as cytokine production by CD4+ and CD8+ cells were alike in co-infected and FV-infected mice. Increased viral loads in co-infected mice were associated with reduced titres of neutralising FV-specific IgG2b and IgG2c antibodies. In summary our findings suggest that helminth infection interfered with the control of retroviral infection by dampening the virus-specific neutralising antibody response. The coincidental infection of a host with two different pathogens is widespread in low-income countries. Regions where helminth infections are endemic strongly overlap with areas where the incidence of viral infections such as HIV is high. HIV is a major public health issue causing more than 1 million deaths per year. To analyse the impact of a pre-existing helminth infection on a viral infection we established a helminth/retrovirus co-infection mouse model. Mice that were first infected with Litomosoides sigmodontis and subsequently with a murine retrovirus showed a more severe course of virus infection, i.e. exaggerated splenomegaly and higher viral loads. Since different lymphocytes such as B and T cells contribute to viral control we analysed the cellular and humoral immune response. While T cell responses were similar in co-infected and virus-infected mice, we observed reduced titres of virus-specific antibodies in co-infected mice. Our results suggest that helminth infection interfered with viral control by dampening the virus-specific antibody response. The viral infection itself altered the humoral immune response against L. sigmodontis without changing the worm burden. In summary, our data highlight the importance of deworming programs or vaccines against helminths in developing countries where the incidence of helminth/HIV co-infections is high.
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Affiliation(s)
- Kirsten Katrin Dietze
- Institute of Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Ulf Dittmer
- Institute of Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Daniel Karim Koudaimi
- Institute of Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Simone Schimmer
- Institute of Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Martina Reitz
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Minka Breloer
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Wiebke Hartmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- * E-mail:
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10
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Pionnier N, Brotin E, Karadjian G, Hemon P, Gaudin-Nomé F, Vallarino-Lhermitte N, Nieguitsila A, Fercoq F, Aknin ML, Marin-Esteban V, Chollet-Martin S, Schlecht-Louf G, Bachelerie F, Martin C. Neutropenic Mice Provide Insight into the Role of Skin-Infiltrating Neutrophils in the Host Protective Immunity against Filarial Infective Larvae. PLoS Negl Trop Dis 2016; 10:e0004605. [PMID: 27111140 PMCID: PMC4844152 DOI: 10.1371/journal.pntd.0004605] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 03/12/2016] [Indexed: 01/06/2023] Open
Abstract
Our knowledge and control of the pathogenesis induced by the filariae remain limited due to experimental obstacles presented by parasitic nematode biology and the lack of selective prophylactic or curative drugs. Here we thought to investigate the role of neutrophils in the host innate immune response to the infection caused by the Litomosoides sigmodontis murine model of human filariasis using mice harboring a gain-of-function mutation of the chemokine receptor CXCR4 and characterized by a profound blood neutropenia (Cxcr4+/1013). We provided manifold evidence emphasizing the major role of neutrophils in the control of the early stages of infection occurring in the skin. Firstly, we uncovered that the filarial parasitic success was dramatically decreased in Cxcr4+/1013 mice upon subcutaneous delivery of the infective stages of filariae (infective larvae, L3). This protection was linked to a larger number of neutrophils constitutively present in the skin of the mutant mice herein characterized as compared to wild type (wt) mice. Indeed, the parasitic success in Cxcr4+/1013 mice was normalized either upon depleting neutrophils, including the pool in the skin, or bypassing the skin via the intravenous infection of L3. Second, extending these observations to wt mice we found that subcutaneous delivery of L3 elicited an increase of neutrophils in the skin. Finally, living L3 larvae were able to promote in both wt and mutant mice, an oxidative burst response and the release of neutrophil extracellular traps (NET). This response of neutrophils, which is adapted to the large size of the L3 infective stages, likely directly contributes to the anti-parasitic strategies implemented by the host. Collectively, our results are demonstrating the contribution of neutrophils in early anti-filarial host responses through their capacity to undertake different anti-filarial strategies such as oxidative burst, degranulation and NETosis. Filariases are chronic debilitating diseases caused by parasitic nematodes affecting more than 150 million people worldwide. None of the current drugs are selective, neither able to eliminate the parasites nor to prevent new infections once the drug pressure has waned. Therefore, blocking the entry and the migration of the infective larvae (L3) could be an efficient way to control the infection. In the present study we investigated the early interaction between the host and the L. sigmodontis murine filariasis with a focus on the neutrophils in the innate host responses. We uncovered a key role of neutrophils in the control of infection provided by the CXCR4-gain-of-function mice (Cxcr4+/1013) that display a blood neutropenia as well as an accumulation of skin-infiltrating neutrophils. Overall, we reveal that in the early phase of filariasis, i.e. after L3 are delivered into the skin and before they reach their site for reproduction, neutrophils are critical elements of the host innate protective response arsenal. A better understanding of their indirect and/or effector role(s) may provide mechanistic clues to host factors implicated in parasitic nematode entry and potentially lead to the identification of new drug targets.
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Affiliation(s)
- Nicolas Pionnier
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Emilie Brotin
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Gregory Karadjian
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
| | - Patrice Hemon
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
- US31-UMS3679 -Plateforme PLAIMMO, Institut Paris-Saclay d’Innovation Thérapeutique (IPSIT), Inserm, CNRS, Univ Paris-Sud, Université Paris-Saclay, Clamart, France
| | - Françoise Gaudin-Nomé
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
- US31-UMS3679 -Plateforme PLAIMMO, Institut Paris-Saclay d’Innovation Thérapeutique (IPSIT), Inserm, CNRS, Univ Paris-Sud, Université Paris-Saclay, Clamart, France
| | - Nathaly Vallarino-Lhermitte
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
| | - Adélaïde Nieguitsila
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
| | - Frédéric Fercoq
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
| | - Marie-Laure Aknin
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Viviana Marin-Esteban
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Sylvie Chollet-Martin
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Géraldine Schlecht-Louf
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Françoise Bachelerie
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
- * E-mail: (FB); (CM)
| | - Coralie Martin
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
- * E-mail: (FB); (CM)
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11
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Gondorf F, Berbudi A, Buerfent BC, Ajendra J, Bloemker D, Specht S, Schmidt D, Neumann AL, Layland LE, Hoerauf A, Hübner MP. Chronic filarial infection provides protection against bacterial sepsis by functionally reprogramming macrophages. PLoS Pathog 2015; 11:e1004616. [PMID: 25611587 PMCID: PMC4303312 DOI: 10.1371/journal.ppat.1004616] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 12/09/2014] [Indexed: 12/26/2022] Open
Abstract
Helminths immunomodulate their hosts and induce a regulatory, anti-inflammatory milieu that prevents allergies and autoimmune diseases. Helminth immunomodulation may benefit sepsis outcome by preventing exacerbated inflammation and severe pathology, but the influence on bacterial clearance remains unclear. To address this, mice were chronically infected with the filarial nematode Litomosoides sigmodontis (L.s.) and the outcome of acute systemic inflammation caused by i.p. Escherichia coli injection was determined. L.s. infection significantly improved E. coli-induced hypothermia, bacterial clearance and sepsis survival and correlated with reduced concentrations of associated pro-inflammatory cytokines/chemokines and a less pronounced pro-inflammatory macrophage gene expression profile. Improved sepsis outcome in L.s.-infected animals was mediated by macrophages, but independent of the alternatively activated macrophage subset. Endosymbiotic Wolbachia bacteria that are present in most human pathogenic filariae, as well as L.s., signal via TLR2 and modulate macrophage function. Here, gene expression profiles of peritoneal macrophages from L.s.-infected mice revealed a downregulation of genes involved in TLR signaling, and pulsing of macrophages in vitro with L.s. extract reduced LPS-triggered activation. Subsequent transfer improved sepsis outcome in naïve mice in a Wolbachia- and TLR2-dependent manner. In vivo, phagocytosis was increased in macrophages from L.s.-infected wild type, but not TLR2-deficient animals. In association, L.s. infection neither improved bacterial clearance in TLR2-deficient animals nor ameliorated E. coli-induced hypothermia and sepsis survival. These results indicate that chronic L.s. infection has a dual beneficial effect on bacterial sepsis, reducing pro-inflammatory immune responses and improving bacterial control. Thus, helminths and their antigens may not only improve the outcome of autoimmune and allergic diseases, but may also present new therapeutic approaches for acute inflammatory diseases that do not impair bacterial control. As the human immune system evolved in the presence of helminth infections, it is postulated that improved hygiene and subsequent loss of helminth infections and their immunomodulatory functions contributed to the sharp increase of autoimmune diseases and allergies over the last decades. Accordingly, helminth-induced anti-inflammatory, regulatory immune responses ameliorate allergy and autoimmune diseases and are likely to impact other immunological disorders including sepsis. Sepsis is an exacerbated, systemic inflammatory disease that occurs when pathogens cannot be locally confined and spread via the blood stream. Thus, efficient sepsis therapies should reduce excessive inflammation without impairing protective immune responses. In the present study we demonstrate that chronic filarial infection modulates macrophages to a less pro-inflammatory phenotype with improved phagocytic capacity. This immunomodulation reduces sepsis-induced inflammation and hypothermia and clears bacteria more efficiently thus improving sepsis survival. Moreover, we found that Wolbachia, the endosymbiotic bacteria of filariae, play a crucial role in triggering the correct macrophage response via TLR2. Thus, our observations suggest that helminths and helminth-derived antigens may not only present new treatment options for allergies and autoimmune diseases, but may also allow treatment of sepsis caused inflammation without impairing bacterial control.
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Affiliation(s)
- Fabian Gondorf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Afiat Berbudi
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Benedikt C. Buerfent
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Jesuthas Ajendra
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Dominique Bloemker
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany
| | - Sabine Specht
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - David Schmidt
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Anna-Lena Neumann
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Laura E. Layland
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Marc P. Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
- * E-mail:
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12
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Haben I, Hartmann W, Breloer M. Nematode-induced interference with vaccination efficacy targets follicular T helper cell induction and is preserved after termination of infection. PLoS Negl Trop Dis 2014; 8:e3170. [PMID: 25255463 PMCID: PMC4177885 DOI: 10.1371/journal.pntd.0003170] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 08/05/2014] [Indexed: 12/14/2022] Open
Abstract
One-third of the human population is infected with parasitic worms. To avoid being eliminated, these parasites actively dampen the immune response of their hosts. This immune modulation also suppresses immune responses to third-party antigens such as vaccines. Here, we used Litomosoides sigmodontis-infected BALB/c mice to analyse nematode-induced interference with vaccination. Chronic nematode infection led to complete suppression of the humoral response to thymus-dependent vaccination. Thereby the numbers of antigen-specific B cells as well as the serum immunoglobulin (Ig) G titres were reduced. TH2-associated IgG1 and TH1-associated IgG2 responses were both suppressed. Thus, nematode infection did not bias responses towards a TH2 response, but interfered with Ig responses in general. We provide evidence that this suppression indirectly targeted B cells via accessory T cells as number and frequency of vaccine-induced follicular B helper T cells were reduced. Moreover, vaccination using model antigens that stimulate Ig response independently of T helper cells was functional in nematode-infected mice. Using depletion experiments, we show that CD4+Foxp3+ regulatory T cells did not mediate the suppression of Ig response during chronic nematode infection. Suppression was induced by fourth stage larvae, immature adults and mature adults, and increased with the duration of the infection. By contrast, isolated microfilariae increased IgG2a responses to vaccination. This pro-inflammatory effect of microfilariae was overruled by the simultaneous presence of adults. Strikingly, a reduced humoral response was still observed if vaccination was performed more than 16 weeks after termination of L. sigmodontis infection. In summary, our results suggest that vaccination may not only fail in helminth-infected individuals, but also in individuals with a history of previous helminth infections. Parasitic worms, called helminths, infect one-third of the world population. Despite exposure to their host's immune system many helminths establish chronic infections and survive several years within their host. They avoid elimination by dampening the immune response of their hosts. This immune suppression also affects immune responses to third-party antigens such as vaccines. Indeed, accumulating evidence suggests that helminth-infected humans display impaired responses to vaccination. Thus, anthelminthic treatment before vaccination is discussed. Here, we use helminth-infected mice to analyse kinetics and mechanism of helminth-induced interference with vaccination efficacy more precisely. We show that chronic helminth infection completely suppressed antibody responses to a model vaccine. Thereby helminths suppressed the antibody-producing B cells indirectly via suppression of accessory T helper cells. The suppression was more pronounced at later time points of infection and still observed in mice that had terminated the helminth infection for more than 16 weeks. In summary, our results suggest that vaccination may not only fail in helminth-infected individuals, but also in individuals with a history of previous helminth infections. Thus, our report highlights the importance to develop vaccination strategies that are functional despite concurrent helminth infection rather than deworming humans before vaccination.
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Affiliation(s)
- Irma Haben
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Wiebke Hartmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Minka Breloer
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- * E-mail:
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13
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Ajendra J, Specht S, Neumann AL, Gondorf F, Schmidt D, Gentil K, Hoffmann WH, Taylor MJ, Hoerauf A, Hübner MP. ST2 deficiency does not impair type 2 immune responses during chronic filarial infection but leads to an increased microfilaremia due to an impaired splenic microfilarial clearance. PLoS One 2014; 9:e93072. [PMID: 24663956 PMCID: PMC3963995 DOI: 10.1371/journal.pone.0093072] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 02/28/2014] [Indexed: 11/18/2022] Open
Abstract
Background Interactions of the Th2 cytokine IL-33 with its receptor ST2 lead to amplified Type 2 immune responses. As Type 2 immune responses are known to mediate protection against helminth infections we hypothesized that the lack of ST2 would lead to an increased susceptibility to filarial infections. Methodology/Principal Finding ST2 deficient and immunocompetent BALB/c mice were infected with the filarial nematode Litomosoides sigmodontis. At different time points after infection mice were analyzed for worm burden and their immune responses were examined within the thoracic cavity, the site of infection, and systemically using spleen cells and plasma. Absence of ST2 led to significantly increased levels of peripheral blood microfilariae, the filarial progeny, whereas L. sigmodontis adult worm burden was not affected. Development of local and systemic Type 2 immune responses were not impaired in ST2 deficient mice after the onset of microfilaremia, but L. sigmodontis infected ST2-ko mice had significantly reduced total numbers of cells within the thoracic cavity and spleen compared to infected immunocompetent controls. Pronounced microfilaremia in ST2-ko mice did not result from an increased microfilariae release by adult female worms, but an impaired splenic clearance of microfilariae. Conclusions/Significance Our findings suggest that the absence of ST2 does not impair the establishment of adult L. sigmodontis worms, but is important for the splenic clearance of microfilariae from peripheral blood. Thus, ST2 interactions may be important for therapies that intend to block the transmission of filarial disease.
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Affiliation(s)
- Jesuthas Ajendra
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Sabine Specht
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Anna-Lena Neumann
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Fabian Gondorf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - David Schmidt
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Katrin Gentil
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | | | - Mark J. Taylor
- Filariasis Research Laboratory, Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Marc P. Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- * E-mail:
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Abstract
SUMMARY Filarial worms cause highly morbid diseases such as elephantiasis and river blindness. Since the 1940s, researchers have conducted vaccine trials in 27 different animal models of filariasis. Although no vaccine trial in a permissive model of filariasis has provided sterilizing immunity, great strides have been made toward developing vaccines that could block transmission, decrease pathological sequelae, or decrease susceptibility to infection. In this review, we have organized, to the best of our ability, all published filaria vaccine trials and reviewed them in the context of the animal models used. Additionally, we provide information on the life cycle, disease phenotype, concomitant immunity, and natural immunity during primary and secondary infections for 24 different filaria models.
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Affiliation(s)
- C. Paul Morris
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Holly Evans
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Sasha E. Larsen
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Edward Mitre
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
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Babayan SA, Luo H, Gray N, Taylor DW, Allen JE. Deletion of parasite immune modulatory sequences combined with immune activating signals enhances vaccine mediated protection against filarial nematodes. PLoS Negl Trop Dis 2012; 6:e1968. [PMID: 23301106 PMCID: PMC3531514 DOI: 10.1371/journal.pntd.0001968] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 10/30/2012] [Indexed: 11/19/2022] Open
Abstract
Background Filarial nematodes are tissue-dwelling parasites that can be killed by Th2-driven immune effectors, but that have evolved to withstand immune attack and establish chronic infections by suppressing host immunity. As a consequence, the efficacy of a vaccine against filariasis may depend on its capacity to counter parasite-driven immunomodulation. Methodology and Principal Findings We immunised mice with DNA plasmids expressing functionally-inactivated forms of two immunomodulatory molecules expressed by the filarial parasite Litomosoides sigmodontis: the abundant larval transcript-1 (LsALT) and cysteine protease inhibitor-2 (LsCPI). The mutant proteins enhanced antibody and cytokine responses to live parasite challenge, and led to more leukocyte recruitment to the site of infection than their native forms. The immune response was further enhanced when the antigens were targeted to dendritic cells using a single chain Fv-αDEC205 antibody and co-administered with plasmids that enhance T helper 2 immunity (IL-4) and antigen-presenting cell recruitment (Flt3L, MIP-1α). Mice immunised simultaneously against the mutated forms of LsALT and LsCPI eliminated adult parasites faster and consistently reduced peripheral microfilaraemia. A multifactorial analysis of the immune response revealed that protection was strongly correlated with the production of parasite-specific IgG1 and with the numbers of leukocytes present at the site of infection. Conclusions We have developed a successful strategy for DNA vaccination against a nematode infection that specifically targets parasite-driven immunosuppression while simultaneously enhancing Th2 immune responses and parasite antigen presentation by dendritic cells. Filarial infections are endemic in more that 80 countries, affecting over 120 million people and putting 1 billion more at risk. Antifilarial drugs must be administered regularly to infected people to control the disease, but they are contraindicated in under 6 year-olds and in pregnant women. Further, reports of drug resistance are now accumulating. A vaccine would therefore greatly help fight these diseases. Live attenuated L3 filariae larvae can evoke a protective immunity but their production is impractical and use in humans unacceptable while the efficacy of sub-unit vaccines has been poor. Filariae secrete proteins capable of suppressing their host's immune response, and have the potential to interfere with immunisation. We therefore decided to vaccinate hosts against secreted parasite products that modulate host immune responses rather than against structural components of the worms, and to boost the host's immune system by directly enhancing the uptake of parasite material by antigen presenting cells. This strategy generated substantial protection against both adult and offspring of a filarial parasite in mice. This provides a strong proof of principle for the anti-immunomodulatory approach we have developed.
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MESH Headings
- Adjuvants, Immunologic/administration & dosage
- Animals
- Antibodies, Helminth/blood
- Antigens, Helminth/genetics
- Antigens, Helminth/immunology
- Cytokines/metabolism
- DNA, Helminth/administration & dosage
- DNA, Helminth/genetics
- DNA, Helminth/immunology
- Disease Models, Animal
- Female
- Filariasis/immunology
- Filariasis/prevention & control
- Filarioidea/genetics
- Filarioidea/immunology
- Lymphocytes/immunology
- Mice
- Mice, Inbred BALB C
- Sequence Deletion
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/genetics
- Vaccines, DNA/immunology
- Vaccines, Subunit/administration & dosage
- Vaccines, Subunit/genetics
- Vaccines, Subunit/immunology
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Affiliation(s)
- Simon A Babayan
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom.
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16
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Hübner MP, Killoran KE, Rajnik M, Wilson S, Yim KC, Torrero MN, Morris CP, Nikonenko B, Blanco JCG, Hemming VG, Mitre E. Chronic helminth infection does not exacerbate Mycobacterium tuberculosis infection. PLoS Negl Trop Dis 2012; 6:e1970. [PMID: 23285308 PMCID: PMC3529511 DOI: 10.1371/journal.pntd.0001970] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 10/30/2012] [Indexed: 01/15/2023] Open
Abstract
Background Chronic helminth infections induce a Th2 immune shift and establish an immunoregulatory
milieu. As both of these responses can suppress Th1 immunity, which is necessary for
control of Mycobacterium tuberculosis (MTB) infection, we hypothesized
that chronic helminth infections may exacerbate the course of MTB. Methodology/Principal Findings Co-infection studies were conducted in cotton rats as they are the natural host for the
filarial nematode Litomosoides sigmodontis and are an excellent model
for human MTB. Immunogical responses, histological studies, and quantitative
mycobacterial cultures were assessed two months after MTB challenge in cotton rats with
and without chronic L. sigmodontis infection. Spleen cell proliferation
and interferon gamma production in response to purified protein derivative were similar
between co-infected and MTB-only infected animals. In contrast to our hypothesis, MTB
loads and occurrence and size of lung granulomas were not increased in co-infected
animals. Conclusions/Significance These findings suggest that chronic filaria infections do not exacerbate MTB infection
in the cotton rat model. While these results suggest that filaria eradication programs
may not facilitate MTB control, they indicate that it may be possible to develop
worm-derived therapies for autoimmune diseases that do not substantially increase the
risk for infections. Tuberculosis prevalence is high in areas that are endemic for helminths, suggesting that
many people are chronically infected with both pathogens. As parasitic helminths can
suppress the host immune system to facilitate their own survival, they frequently impact
the host immune response to bystander antigens. Thus, while helminth infections ameliorate
allergies and autoimmune diseases, they also decrease immune responses elicited by
vaccines. Several studies have shown that helminth exposure impairs Mycobacterium
tuberculosis-specific immune responses, raising the possibility that helminth
infections may decrease the host's ability to control M.
tuberculosis infection. To test this, we analyzed whether chronic infection of
cotton rats with the filarial worm Litomosoides sigmodontis exacerbates
the course of M. tuberculosis infection. Cotton rats are an excellent
model organism to study human M. tuberculosis as they develop, in
contrast to mice, distinct granuloma formation during infection. In addition, cotton rats
are the natural host for L. sigmodontis, a nematode that establishes
long-lived infections (>2 years) with circulating microfilariae in these animals. The
results of this study demonstrate that chronic filarial infection does not exacerbate
M. tuberculosis-associated pathology or mycobacterial burdens in cotton
rats and suggest that filaria-induced immunoregulation can be overcome to respond
effectively to newly acquired infections.
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Affiliation(s)
- Marc P. Hübner
- Department of Microbiology and Immunology, Uniformed
Services University of the Health Sciences, Bethesda, Maryland, United States of
America
- Institute for Medical Microbiology, Immunology and
Parasitology, University Hospital Bonn, Bonn, Germany
- * E-mail: (EM); (MPH)
| | - Kristin E. Killoran
- Department of Microbiology and Immunology, Uniformed
Services University of the Health Sciences, Bethesda, Maryland, United States of
America
| | - Michael Rajnik
- Department of Pediatrics, Uniformed Services
University of the Health Sciences, Bethesda, Maryland, United States of
America
| | - Samuel Wilson
- Department of Pediatrics, Uniformed Services
University of the Health Sciences, Bethesda, Maryland, United States of
America
| | - Kevin C. Yim
- Virion Systems, Inc., Rockville, Maryland, United
States of America
- Sigmovir Biosystems Inc., Rockville, Maryland,
United States of America
| | - Marina N. Torrero
- Department of Microbiology and Immunology, Uniformed
Services University of the Health Sciences, Bethesda, Maryland, United States of
America
| | - Christopher P. Morris
- Department of Microbiology and Immunology, Uniformed
Services University of the Health Sciences, Bethesda, Maryland, United States of
America
| | - Boris Nikonenko
- Sequella, Inc., Rockville, Maryland, United States
of America
| | - Jorge C. G. Blanco
- Virion Systems, Inc., Rockville, Maryland, United
States of America
- Sigmovir Biosystems Inc., Rockville, Maryland,
United States of America
| | - Val G. Hemming
- Department of Pediatrics, Uniformed Services
University of the Health Sciences, Bethesda, Maryland, United States of
America
- Virion Systems, Inc., Rockville, Maryland, United
States of America
| | - Edward Mitre
- Department of Microbiology and Immunology, Uniformed
Services University of the Health Sciences, Bethesda, Maryland, United States of
America
- * E-mail: (EM); (MPH)
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17
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Ziewer S, Hübner MP, Dubben B, Hoffmann WH, Bain O, Martin C, Hoerauf A, Specht S. Immunization with L. sigmodontis microfilariae reduces peripheral microfilaraemia after challenge infection by inhibition of filarial embryogenesis. PLoS Negl Trop Dis 2012; 6:e1558. [PMID: 22413031 PMCID: PMC3295809 DOI: 10.1371/journal.pntd.0001558] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 01/24/2012] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Lymphatic filariasis and onchocerciasis are two chronic diseases mediated by parasitic filarial worms causing long term disability and massive socioeconomic problems. Filariae are transmitted by blood-feeding mosquitoes that take up the first stage larvae from an infected host and deliver it after maturation into infective stage to a new host. After closure of vector control programs, disease control relies mainly on mass drug administration with drugs that are primarily effective against first stage larvae and require many years of annual/biannual administration. Therefore, there is an urgent need for alternative treatment ways, i.e. other effective drugs or vaccines. METHODOLOGY/PRINCIPAL FINDINGS Using the Litomosoides sigmodontis murine model of filariasis we demonstrate that immunization with microfilariae together with the adjuvant alum prevents mice from developing high microfilaraemia after challenge infection. Immunization achieved 70% to 100% protection in the peripheral blood and in the pleural space and furthermore strongly reduced the microfilarial load in mice that remained microfilaraemic. Protection was associated with the impairment of intrauterine filarial embryogenesis and with local and systemic microfilarial-specific host IgG, as well as IFN-γ secretion by host cells from the site of infection. Furthermore immunization significantly reduced adult worm burden. CONCLUSIONS/SIGNIFICANCE Our results present a tool to understand the immunological basis of vaccine induced protection in order to develop a microfilariae-based vaccine that reduces adult worm burden and prevents microfilaraemia, a powerful weapon to stop transmission of filariasis.
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Affiliation(s)
- Sebastian Ziewer
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Marc P. Hübner
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Bettina Dubben
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Wolfgang H. Hoffmann
- Institute of Tropical Medicine, University Hospital Tuebingen, Tuebingen, Germany
| | - Odile Bain
- UMR 7245 MCAM MNHN CNRS, Muséum National d'Histoire Naturelle, Paris, France
| | - Coralie Martin
- UMR 7245 MCAM MNHN CNRS, Muséum National d'Histoire Naturelle, Paris, France
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Sabine Specht
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- * E-mail:
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18
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Abstract
Inflammation leads to local accumulation of macrophages. A new study shows that macrophage accumulation in inflammatory reactions dominated by type 2 immune responses is a result of local cell proliferation as opposed to recruitment of monocytes from the blood.
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Affiliation(s)
- Laura Helming
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany.
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19
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Yadav M, Liebau E, Haldar C, Rathaur S. Identification of major antigenic peptide of filarial glutathione-S-transferase. Vaccine 2010; 29:1297-303. [PMID: 21144917 DOI: 10.1016/j.vaccine.2010.11.078] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 11/20/2010] [Accepted: 11/22/2010] [Indexed: 01/10/2023]
Abstract
In our earlier report, a 26kDa Setaria cervi glutathione-S-transferase showed significant protection (82%) in jirds infected with L3 larvae of Brugia malayi. In the present study we have identified the major antigenic epitopes in ScGST. Carboxypeptidase B has been used to digest the ScGST in to smaller fragments. The digested products were separated as four protein bands on SDS-PAGE. The smallest fragment of 6kDa (P4) from ScGST was identified as major antigenic epitope because of its significant reactivity with jird anti ScGST sera and human filarial sera in immunoblotting. The MALDI-LC/MS sequencing of ScGST P4 peptide ((5)KLTYFSIRGRGLAEPIRL(20), (22)KVPDDQQFLDDLISR(36) and (47)VFHFGQGPHHGPPR(62)) suggested that this protein band has a fragment of 5-62 residues long that matched with the N-terminal end of filarial GST. The antigenicity plot of ScGST was compared with BmGST model and both exhibited three immunogenic peaks within the first 60 residues towards N-terminal. In BmGST the N-terminal region was also detected with N-glycosylation signal peptide NAS adding to its high immunogenic property. Further, P4 showed strong reactivity with IgG1 and IL-4 response in endemic normal sera suggested its role in Th2 response which in turn is correlated with antibody dependent cell mediated cytotoxicity. Thus taking these results into account we propose 5-62 residues long N-terminal peptide of GST as a potential target for further vaccination studies against filarial infection.
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Affiliation(s)
- Marshleen Yadav
- Department of Biochemistry, Banaras Hindu University, Varanasi 221005, India
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20
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Fairlie-Clarke KJ, Lamb TJ, Langhorne J, Graham AL, Allen JE. Antibody isotype analysis of malaria-nematode co-infection: problems and solutions associated with cross-reactivity. BMC Immunol 2010; 11:6. [PMID: 20163714 PMCID: PMC2838755 DOI: 10.1186/1471-2172-11-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Accepted: 02/17/2010] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Antibody isotype responses can be useful as indicators of immune bias during infection. In studies of parasite co-infection however, interpretation of immune bias is complicated by the occurrence of cross-reactive antibodies. To confidently attribute shifts in immune bias to the presence of a co-infecting parasite, we suggest practical approaches to account for antibody cross-reactivity. The potential for cross-reactive antibodies to influence disease outcome is also discussed. RESULTS Utilising two murine models of malaria-helminth co-infection we analysed antibody responses of mice singly- or co-infected with Plasmodium chabaudi chabaudi and Nippostrongylus brasiliensis or Litomosoides sigmodontis. We observed cross-reactive antibody responses that recognised antigens from both pathogens irrespective of whether crude parasite antigen preparations or purified recombinant proteins were used in ELISA. These responses were not apparent in control mice. The relative strength of cross-reactive versus antigen-specific responses was determined by calculating antibody titre. In addition, we analysed antibody binding to periodate-treated antigens, to distinguish responses targeted to protein versus carbohydrate moieties. Periodate treatment affected both antigen-specific and cross-reactive responses. For example, malaria-induced cross-reactive IgG1 responses were found to target the carbohydrate component of the helminth antigen, as they were not detected following periodate treatment. Interestingly, periodate treatment of recombinant malaria antigen Merozoite Surface Protein-119 (MSP-119) resulted in increased detection of antigen-specific IgG2a responses in malaria-infected mice. This suggests that glycosylation may have been masking protein epitopes and that periodate-treated MSP-119 may more closely reflect the natural non-glycosylated antigen seen during infection. CONCLUSIONS In order to utilize antibody isotypes as a measure of immune bias during co-infection studies, it is important to dissect antigen-specific from cross-reactive antibody responses. Calculating antibody titre, rather than using a single dilution of serum, as a measure of the relative strength of the response, largely accomplished this. Elimination of the carbohydrate moiety of an antigen that can often be the target of cross-reactive antibodies also proved useful.
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Affiliation(s)
- Karen J Fairlie-Clarke
- Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, King's Buildings, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JT, UK
| | - Tracey J Lamb
- Current address: School of Biological Sciences, The University of Reading, Reading, Berks RG6 6UB, UK
| | - Jean Langhorne
- Division of Parasitology, National Institute for Medical Research, The Ridgeway Mill Hill, NW7 1AA, UK
| | - Andrea L Graham
- Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, King's Buildings, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JT, UK
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Judith E Allen
- Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, King's Buildings, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JT, UK
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21
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Babu S, Bhat SQ, Kumar NP, Anuradha R, Kumaran P, Gopi PG, Kolappan C, Kumaraswami V, Nutman TB. Attenuation of toll-like receptor expression and function in latent tuberculosis by coexistent filarial infection with restoration following antifilarial chemotherapy. PLoS Negl Trop Dis 2009; 3:e489. [PMID: 19636364 PMCID: PMC2710006 DOI: 10.1371/journal.pntd.0000489] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Accepted: 06/23/2009] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) and filarial coinfection is highly prevalent, and the presence of filarial infections may regulate the Toll-like receptor (TLR)-dependent immune response needed to control Mtb infection. By analyzing the baseline and mycobacterial antigen–stimulated expression of TLR1, 2, 4, and 9 (in individuals with latent tuberculosis [TB] with or without filarial infection), we were able to demonstrate that filarial infection, coincident with Mtb, significantly diminishes both baseline and Mtb antigen-specific TLR2 and TLR9 expression. In addition, pro-inflammatory cytokine responses to TLR2 and 9 ligands are significantly diminished in filaria/TB-coinfected individuals. Definitive treatment of lymphatic filariasis significantly restores the pro-inflammatory cytokine responses in individuals with latent TB. Coincident filarial infection exerted a profound inhibitory effect on protective mycobacteria-specific TLR-mediated immune responses in latent tuberculosis and suggests a novel mechanism by which concomitant filarial infections predispose to the development of active tuberculosis in humans. Lymphatic filariasis afflicts over 120 million people worldwide, while Mycobacterium tuberculosis infects over 2 billion people worldwide. Almost 90% of infected people harbor latent tuberculosis infection with no clinical manifestations. Toll-like receptors (TLRs), pattern-recognition receptors that are present on host immune cells, constitute an important facet of host immune response initiation against a variety of pathogens. Because lymphatic filariasis and tuberculosis are co-endemic in many parts of the world and because TLR modulation is an important feature of both infections, we examined the effect of coexisting filarial infection on TLR-specific immune responses in latent tuberculosis by comparing cellular immune responses to Toll ligands in individuals with latent tuberculosis with or without concomitant lymphatic filariasis. We first examined modulation of TLRs at the gene expression level and determined that downregulation of TLR2 and 9 is associated with coexisting filarial infection. We then determined that Toll ligand-induced pro-inflammatory cytokine production—which is crucial in host defense against TB—is diminished in the presence of filarial coinfection. Treatment of filarial infection restores cytokine production in individuals with latent TB. Thus, we conclude that coexisting filarial infections might significantly compromise essential immune responses in tuberculosis and that treatment of filarial infections would potentially confer tremendous benefit in combating tuberculosis.
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Affiliation(s)
- Subash Babu
- National Institutes of Health-International Center for Excellence in Research, Chennai, India.
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22
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Abstract
ABSTRACTExtracts of Dirofilaria immitis adults and microfilariae cause the dcgranulation of mast cells in rat mesentery when applied in vitro and also cause increased vascular permeability in guinea-pigs and rabbits. Adult worms DUt not microfilariac are able to activate complement in vitro and both stages contain a plasminogen activator. No protcolytic activity or hacmolysins could be detected in cither stage. The possibility that these factors may be important in the pathogencsis of dirofilariasis and in the adverse drug reactions that may follow treatment of microfilaraemic animals with dicthylcarbamazine is discussed.
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23
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Bonofiglio M, Hay J, McPherson C. Lymphatic filariasis: inflammatory response to Wolbachia bacteria in filarial worms. Lymphology 2007; 40:191-192. [PMID: 18365535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- M Bonofiglio
- Biomedical Communications, University of Toronto, Canada.
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24
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Taylor MD, Harris A, Babayan SA, Bain O, Culshaw A, Allen JE, Maizels RM. CTLA-4 and CD4+ CD25+ regulatory T cells inhibit protective immunity to filarial parasites in vivo. J Immunol 2007; 179:4626-34. [PMID: 17878360 DOI: 10.4049/jimmunol.179.7.4626] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The T cell coinhibitory receptor CTLA-4 has been implicated in the down-regulation of T cell function that is a quintessential feature of chronic human filarial infections. In a laboratory model of filariasis, Litomosoides sigmodontis infection of susceptible BALB/c mice, we have previously shown that susceptibility is linked both to a CD4+ CD25+ regulatory T (Treg) cell response, and to the development of hyporesponsive CD4+ T cells at the infection site, the pleural cavity. We now provide evidence that L. sigmodontis infection drives the proliferation and activation of CD4+ Foxp3+ Treg cells in vivo, demonstrated by increased uptake of BrdU and increased expression of CTLA-4, Foxp3, GITR, and CD25 compared with naive controls. The greatest increases in CTLA-4 expression were, however, seen in the CD4+ Foxp3- effector T cell population which contained 78% of all CD4+ CTLA-4+ cells in the pleural cavity. Depletion of CD25+ cells from the pleural CD4+ T cell population did not increase their Ag-specific proliferative response in vitro, suggesting that their hyporesponsive phenotype is not directly mediated by CD4+ CD25+ Treg cells. Once infection had established, killing of adult parasites could be enhanced by neutralization of CTLA-4 in vivo, but only if performed in combination with the depletion of CD25+ Treg cells. This work suggests that during filarial infection CTLA-4 coinhibition and CD4+ CD25+ Treg cells form complementary components of immune regulation that inhibit protective immunity in vivo.
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Affiliation(s)
- Matthew D Taylor
- Institute of Immunology and Infection Research, University of Edinburgh, United Kingdom.
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25
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Abstract
The surface of the filarial worm consists of an extracellular cuticle which overlies the outer plasma membrane of the hypodermis. The cuticle is permeable to a wide range of molecules of low molecular weight, and L-amino acid and D-glucose uptake occurs transcuticularly by active transport and diffusion in physiologically significant amounts. Transport mechanisms are associated with the plasma membrane of the hypodermis, and the cuticle may be considered an 'unstirred layer' distal to the transport loci. The outermost layer of the cuticle, or epicuticle, consists of a lipid bilayer which differs from a typical plasma membrane. There is no conclusive evidence for turnover of the epicuticular materials between the larval moults and in the adult stage. It is proposed that the filarial surface does not show the dynamic properties associated with the surface membranes of parasitic cestodes and trematodes.
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26
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Silva LF, Brayner FAS, Santos ACO, Lanfredi RM, Peixoto CA. Identification and location of albumin-like antigens in third-stage larva of W. bancrofti, in adult forms of Litomosoides chagasfilhoi and in the free-living nematode Caenorhabditis elegans. Micron 2006; 37:666-74. [PMID: 16516479 DOI: 10.1016/j.micron.2006.01.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 01/18/2006] [Accepted: 01/19/2006] [Indexed: 11/23/2022]
Abstract
Antigens resembling those of host proteins have been identified on the surface of several filarial parasites, such as immunoglobulins and serum albumins. The origin of albumin-like antigens on filarial parasites remains unclear. Several authors suggested that they have been adsorbed, or that they were metabolic waste products from nutritional utilization of human albumin, or perhaps a contamination with human products. This study searched for human albumin-like antigens by Western blot and ultrastructural analyses on filarial parasites, third stage of W. bancrofti and adult females of Litomosoides chagasfilhoi, and on the free-living Caenorhabditis elegans nematode. Our results showed approximately 67kDa proteins recognized by anti-human albumin antibodies on extracts and excretory-secretory (ES) products of the third-stage W. bancrofti. Similar albumin-like proteins were also detected on the filarial parasite L. chagasfilhoi and on C. elegans extracts. The immunocytochemistry analysis showed human albumin-like antigens on similar tissues of these nematodes. These results provide evidence that these proteins have antigenic similarity and similar distribution in nematodes tissues. Our observations suggest that albumin-like antigens presented on filarial parasites are not acquired from the host, but rather are shared antigenic determinants found even in the third-stage larvae recovered from the invertebrate host.
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Affiliation(s)
- L F Silva
- Departamento de Biologia Celular e Ultraestrutura, Centro de Pesquisas Aggeu Magalhães (FIOCRUZ), Brazil
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27
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Houston KM, Egan CA, García P, Harnett W. Investigation of strategies with potential for producing a phosphorylcholine-free version of the filarial nematode immunomodulator, ES-62. J Helminthol 2006; 80:261-5. [PMID: 16923269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Phosphorylcholine (PC) is found attached to N-type glycans of proteins secreted by filarial nematodes, where it appears to act as an immunomodulator. Based on information on the structure and biosynthesis of the PC-glycan of a major secreted protein, ES-62, strategies were designed with potential for preparing PC-free material to better understand the importance of PC in filarial nematode immunomodulation. The strategies involve either enzymatic removal of PC or inhibition of its attachment during ES-62 synthesis. No method tested was found to be 100% effective although approximately 70% removal was obtained by culturing worms in Et18OCH3. Reasons for failure to obtain complete absence of PC moieties are discussed in relation to the structure and synthesis of PC-glycans and in addition PC-glycan biosynthesis is briefly commented on as a target for chemotherapy.
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Affiliation(s)
- K M Houston
- Department of Immunology, University of Strathclyde, Glasgow, G4 0NR, UK
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28
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Babayan SA, Attout T, Harris A, Taylor MD, Le Goff L, Vuong PN, Rénia L, Allen JE, Bain O. Vaccination against filarial nematodes with irradiated larvae provides long-term protection against the third larval stage but not against subsequent life cycle stages. Int J Parasitol 2006; 36:903-14. [PMID: 16765354 DOI: 10.1016/j.ijpara.2006.04.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 03/17/2006] [Accepted: 04/03/2006] [Indexed: 10/24/2022]
Abstract
Sustainable control of human filariasis would benefit enormously from the development of an effective vaccine. The ability to vaccinate experimental animals, with reductions in worm burden of over 70%, suggests this aim is possible. However, in experimental vaccinations the challenge is usually administered 2 weeks after the immunisation phase and thus the protection obtained is likely to be biased by persisting inflammation. Using the murine model Litomosoides sigmodontis, we increased the time between immunisation with irradiated larvae and challenge with fully infective L3 to 5 months. Significant protection was achieved (54-58%) and the reduced worm burden was observed by 10 days p.i. The developmental stage targeted was the L3, since no nematodes died once they reached the pleural cavity of vaccinated mice, as has been previously shown in short-term protocols. However, larval developmental rate was faster in vaccinated than in primary-infected mice. Immunological assessments were made prior to challenge and then from 6 h to 34 days post-challenge. Samples were taken from the subcutaneous tissue where the larvae were inoculated, the lymph nodes through which they migrate and the pleural cavity in which they establish. Eosinophils were still present although scarce in the subcutaneous tissue of vaccinated mice before challenge. Cytokine and specific antibody production of vaccinated and challenged mice were L3-specific and Th2-biased and greatly exceeded the response of primary-infected mice. The heightened Th2 response may explain the faster development of the filarial worms in vaccinated mice. Thus, long-term vaccination protocols generated a strong memory response that led to significant but incomplete protection that was limited to the infective larval stage suggesting alternative vaccination strategies are needed.
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Affiliation(s)
- Simon A Babayan
- Parasitologie Comparée et Modèles Expérimentaux, Muséum National d'Histoire Naturelle, 75005 Paris, France
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29
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Abstract
AIM The present study was carried out to detect an association between isolated non-communicable hydrocoele and filariasis and to provide awareness to positive patients regarding sequel and advising methods for the reduction of morbidity. METHODS Blood samples and hydrocoele fluids were used to detect filarial antigen and antibody by ICT Kit, Trop-bio kit and Sevafilachek Kit. These were followed by statistical evaluation by chi2 test. RESULTS 14% of cases were positive for filarial antigen and antibody in hydrocoele patient serum, while 15% of cases were positive for filarial antigen and antibody in the serum of non-hydrocoele patients. CONCLUSION Probability is less than 0.05, which is statistically significant.
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Affiliation(s)
- Ravishankar S Goel
- General Surgery Department, New Civil Hospital, Government Medical College, Surat, Gujarat, India.
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30
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Taylor MD, Harris A, Nair MG, Maizels RM, Allen JE. F4/80+Alternatively Activated Macrophages Control CD4+T Cell Hyporesponsiveness at Sites Peripheral to Filarial Infection. J Immunol 2006; 176:6918-27. [PMID: 16709852 DOI: 10.4049/jimmunol.176.11.6918] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Both T cells and APC have been strongly implicated in the immune suppression observed during filarial nematode infections, but their relative roles are poorly understood, particularly in regard to timing and locality of action. Using Litomosoides sigmodontis infection of susceptible BALB/c mice, we have studied the progression of filarial immunosuppression leading to patent infection with blood microfilaremia. Patent infection is associated with decreased immune responsiveness in the draining thoracic lymph nodes (tLN) and intrinsically hyporesponsive CD4+ T cells at the infection site. We now show that we are able to separate, both in time and space, different suppressive mechanisms and cell populations that contribute to filarial hyporesponsiveness. L. sigmodontis infection recruited a F4/80+ population of alternatively activated macrophages that potently inhibited Ag-specific CD4+ T cell proliferative responses even in the presence of competent naive APC. T cell responsiveness was partially restored by neutralizing TGF-beta, but not by blocking IL-10 or CTLA-4 signaling. During prepatent infection, the macrophage population was restricted to the infection site. However, once infection became patent with systemic release of microfilariae, the suppressive macrophage activity extended peripherally into the tLN. In contrast, the hyporesponsive CD4+ T cell phenotype remained localized at the infection site, and the tLN CD4+ T cell population recovered full Ag responsiveness in the absence of suppressive macrophages. Filarial immunosuppression, therefore, evolves over time at sites increasingly distal to infection, and the mechanisms of filarial down-regulation are dependent on proximity to the infection site.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigen-Presenting Cells/immunology
- Antigen-Presenting Cells/parasitology
- Antigen-Presenting Cells/pathology
- Antigens, Differentiation/biosynthesis
- Antigens, Differentiation/physiology
- Antigens, Differentiation, Myelomonocytic/physiology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- CD4-Positive T-Lymphocytes/parasitology
- Cell Movement/immunology
- Cells, Cultured
- Female
- Filariasis/immunology
- Filariasis/parasitology
- Filariasis/pathology
- Filarioidea/growth & development
- Filarioidea/immunology
- Immune Tolerance
- Immunophenotyping
- Lymph Nodes/immunology
- Lymph Nodes/parasitology
- Lymph Nodes/pathology
- Macrophage Activation/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Transgenic
- Molecular Sequence Data
- Pleural Cavity/immunology
- Pleural Cavity/parasitology
- Pleural Cavity/pathology
- T-Lymphocytes, Regulatory/cytology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/parasitology
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Affiliation(s)
- Matthew D Taylor
- Institute of Immunology and Infection Research, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
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31
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Babu S, Blauvelt CP, Kumaraswami V, Nutman TB. Cutting edge: diminished T cell TLR expression and function modulates the immune response in human filarial infection. J Immunol 2006; 176:3885-9. [PMID: 16547219 DOI: 10.4049/jimmunol.176.7.3885] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Patent lymphatic filariasis is characterized by profound Ag-specific T cell hyporesponsiveness with impaired IFN-gamma and IL-2 production. Because T cells have been shown to express a number of TLR and to respond to TLR ligands, we hypothesized that diminished T cell TLR function could partially account for the T cell hyporesponsiveness in filariasis. T cells expressed TLR1, TLR2, TLR4, and TLR9, and the baseline expression of TLR1, TLR2, and TLR4, but not TLR9 was significantly lower in T cells of the filarial-infected individuals compared with the uninfected individuals (both endemic and nonendemic). TLR function was significantly diminished in the T cells of filarial-infected individuals based on decreased T cell activation/cytokine production in response to TLR ligands. Thus, diminished expression and function of T cell TLR is a novel mechanism underlying T cell immune tolerance in lymphatic filariasis.
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Affiliation(s)
- Subash Babu
- Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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32
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Abstract
Filarial nematodes achieve longevity within the infected host by suppressing and modulating the host immune response. To do this, the worms actively secrete products that have been demonstrated to possess immunomodulatory properties. In this article we discuss the immunomodulatory effects of the phosphorylcholine-containing filarial nematode secreted glycoprotein ES-62. In particular we describe how it modulates intracellular signal transduction pathways in a number of different cells of the immune system, in particular B-lymphocytes, T-lymphocytes, macrophages and dendritic cells.
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Affiliation(s)
- W Harnett
- Department of Immunology, University of Strathclyde, Glasgow, UK.
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33
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Abstract
In order to chronically infect their hosts, filarial nematodes have generated a range of strategies to evade and down-modulate the host's immune system. The recent concept of suppression of immune responses by regulatory T cells has in part benefited from examinations in human and murine filariasis. Its further development in basic immunology animal models has in turn helped to better understand down-regulatory immune mechanisms in filariasis. Thus, filarial nematodes orchestrate down-regulation by inducing regulatory T cells and alternatively activated macrophages, which are able to suppress both Th1 and Th2 responses. Regulatory T cells can also induce the secretion of IgG4 from B cells as another arm of modulation. Dendritic cells are down-regulated upon first encounter with infective L3 larvae. Failure to respond to down-regulatory induction is based on genetic traits in hosts and leads to reduced parasite loads, albeit at the expense of pathology and disease. Since down-regulation in chronically and heavily infected hosts extends to third-party antigens, it is essential to analyse the impact of filarial infection for vaccination, allergy and important coinfections such as malaria, in order to foresee and avert potentially disastrous consequences of filariasis control programmes.
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Affiliation(s)
- A Hoerauf
- Institute for Medical Parasitology, University Clinic Bonn, Sigmund Freud Strasse 25, 53105 Bonn, Germany.
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34
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Lamb TJ, Graham AL, Le Goff L, Allen JE. Co-infected C57BL/6 mice mount appropriately polarized and compartmentalized cytokine responses to Litomosoides sigmodontis and Leishmania major but disease progression is altered. Parasite Immunol 2005; 27:317-24. [PMID: 16149989 DOI: 10.1111/j.1365-3024.2005.00779.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study examines the capacity of the mammalian host to fully compartmentalize the response to infection with type 1 vs. type 2 inducing organisms that infect different sites in the body. For this purpose, C57BL/6 mice were infected with the rodent filarial nematode Litomosoides sigmodontis followed by footpad infection with the protozoan parasite Leishmania major. In this host, nematode infection is established in the thoracic cavity but no microfilariae circulate in the bloodstream. We utilized quantitative ELISPOT analysis of IL-4 and IFN-gamma producing cells to assess cytokine bias and response magnitude in the lymph nodes draining the sites of infection as well as more systemic responses in the spleen and serum. Contrary to other systems where co-infection has a major impact on bias, cytokine ratios were unaltered in either local lymph node. The most notable effect of co-infection was an unexpected increase in the magnitude of the IFN-gamma response to L. major in mice previously infected with L. sigmodontis. Further, lesion development was significantly delayed in these mice. Thus, despite the ability of the immune system to appropriately compartmentalize the immune response, interactions between responses at distinct infection sites can alter disease progression.
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Affiliation(s)
- T J Lamb
- Institutes of Evolution, Immunology, & Infection Research, School of Biological Sciences, University of Edinburgh, UK
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35
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Goodridge HS, Stepek G, Harnett W, Harnett MM. Signalling mechanisms underlying subversion of the immune response by the filarial nematode secreted product ES-62. Immunology 2005; 115:296-304. [PMID: 15946247 PMCID: PMC1782160 DOI: 10.1111/j.1365-2567.2005.02167.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Secretion of immunomodulatory molecules is a key strategy employed by pathogens to enable their survival in host organisms. For example, arthropod-transmitted filarial nematodes, which achieve longevity within the infected host by suppressing and modulating the host immune response, produce excretory-secretory (ES) products that have been demonstrated to possess immunomodulatory properties. In this review we discuss the immunomodulatory effects of the phosphorylcholine-containing filarial nematode-secreted glycoprotein ES-62 and describe the intracellular signal transduction pathways it targets to achieve these effects.
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Affiliation(s)
- Helen S Goodridge
- Division of Immunology, Infection and Inflammation, University of Glasgow, Glasgow G11 6NT, UK
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36
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Taylor MD, LeGoff L, Harris A, Malone E, Allen JE, Maizels RM. Removal of Regulatory T Cell Activity Reverses Hyporesponsiveness and Leads to Filarial Parasite Clearance In Vivo. J Immunol 2005; 174:4924-33. [PMID: 15814720 DOI: 10.4049/jimmunol.174.8.4924] [Citation(s) in RCA: 236] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Human filarial parasites cause chronic infection associated with long-term down-regulation of the host's immune response. We show here that CD4+ T cell regulation is the main determinant of parasite survival. In a laboratory model of infection, using Litomosoides sigmodontis in BALB/c mice, parasites establish for >60 days in the thoracic cavity. During infection, CD4+ T cells at this site express increasing levels of CD25, CTLA-4, and glucocorticoid-induced TNF receptor family-related gene (GITR), and by day 60, up to 70% are CTLA-4(+)GITR(high), with a lesser fraction coexpressing CD25. Upon Ag stimulation, CD4(+)CTLA-4(+)GITR(high) cells are hyporesponsive for proliferation and cytokine production. To test the hypothesis that regulatory T cell activity maintains hyporesponsiveness and prolongs infection, we treated mice with Abs to CD25 and GITR. Combined Ab treatment was able to overcome an established infection, resulting in a 73% reduction in parasite numbers (p < 0.01). Parasite killing was accompanied by increased Ag-specific immune responses and markedly reduced levels of CTLA-4 expression. The action of the CD25(+)GITR+ cells was IL-10 independent as in vivo neutralization of IL-10R did not restore the ability of the immune system to kill parasites. These data suggest that regulatory T cells act, in an IL-10-independent manner, to suppress host immunity to filariasis.
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Affiliation(s)
- Matthew D Taylor
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
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37
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Goodridge HS, Marshall FA, Else KJ, Houston KM, Egan C, Al-Riyami L, Liew FY, Harnett W, Harnett MM. Immunomodulation via novel use of TLR4 by the filarial nematode phosphorylcholine-containing secreted product, ES-62. J Immunol 2005; 174:284-93. [PMID: 15611251 DOI: 10.4049/jimmunol.174.1.284] [Citation(s) in RCA: 181] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Filarial nematodes, parasites of vertebrates, including humans, secrete immunomodulatory molecules into the host environment. We have previously demonstrated that one such molecule, the phosphorylcholine-containing glycoprotein ES-62, acts to bias the immune response toward an anti-inflammatory/Th2 phenotype that is conducive to both worm survival and host health. For example, although ES-62 initially induces macrophages to produce low levels of IL-12 and TNF-alpha, exposure to the parasite product ultimately renders the cells unable to produce these cytokines in response to classic stimulators such as LPS/IFN-gamma. We have investigated the possibility that a TLR is involved in the recognition of ES-62 by target cells, because phosphorylcholine, a common pathogen-associated molecular pattern, appears to be responsible for many of the immunomodulatory properties of ES-62. We now demonstrate that ES-62-mediated, low level IL-12 and TNF-alpha production by macrophages and dendritic cells is abrogated in MyD88 and TLR4, but not TLR2, knockout, mice implicating TLR4 in the recognition of ES-62 by these cells and MyD88 in the transduction of the resulting intracellular signals. We also show that ES-62 inhibits IL-12 induction by TLR ligands other than LPS, bacterial lipopeptide (TLR2) and CpG (TLR9), via this TLR4-dependent pathway. Surprisingly, macrophages and dendritic cells from LPS-unresponsive, TLR4-mutant C3H/HeJ mice respond normally to ES-62. This is the first report to demonstrate that modulation of cytokine responses by a pathogen product can be abrogated in cells derived from TLR4 knockout, but not C3H/HeJ mice, suggesting the existence of a novel mechanism of TLR4-mediated immunomodulation.
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Affiliation(s)
- Helen S Goodridge
- Division of Immunology, Infection, and Inflammation, University of Glasgow, Western Infirmary, Dumbarton Road, Glasgow G11 6NT, Scotland, UK
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38
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Abstract
Interleukin-10 (IL-10) was at first described as a Th2-associated cytokine, although more recent reports have shown that immunosuppression applies to both Th1 and Th2 cell responses, e.g., when produced by T regulatory cells. This concept when applied to human filariasis would argue that high parasite loads are associated with IL-10, while bona fide Th2 responses, mediated by IL-4, IL-5, and IL-13, are associated with parasite containment. To prove this relationship in a causal manner, we investigated the roles of IL-4 and IL-10 in a helminth infection model in which mice genetically deficient for IL-4, IL-10, or IL-4 plus IL-10 were infected with the rodent filaria Litomosoides sigmodontis. Compared to C57BL/6 wild-type and IL-10 knockout (KO) mice, IL-4 KO mice remained susceptible, exhibiting a remarkable number of live adult worms. Interestingly however, when the IL-10 gene was knocked out simultaneously with the IL-4 gene, the susceptibility of IL-4 KO mice was reversed. Although production of IFN-gamma was increased in IL-4/IL-10 double-knockout mice, depletion of gamma interferon did not affect worm elimination, so it seems unlikely to be the major factor in mediating resistance in IL-4/IL-10 KO mice. Taken together, the results of this study add proof to the concept that has arisen for human filariasis that IL-10-dependent responses, which are associated with patency, are antagonistic to bona fide Th2 responses, which control parasite loads. The finding that knockout of IL-10 reversed a disease phenotype induced by knockout of IL-4 gives the first causal evidence of an antagonistic activity between IL-4 and IL-10 in an infection in vivo.
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Affiliation(s)
- Sabine Specht
- Institute for Medical Parasitology, Friedrich Wilhelm University of Bonn, Sigmund-Freud-Str. 25, 53105, Germany
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39
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Babayan S, Attout T, Specht S, Hoerauf A, Snounou G, Rénia L, Korenaga M, Bain O, Martin C. Increased early local immune responses and altered worm development in high-dose infections of mice susceptible to the filaria Litomosoides sigmodontis. Med Microbiol Immunol 2004; 194:151-62. [PMID: 15338299 DOI: 10.1007/s00430-004-0226-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2004] [Indexed: 11/30/2022]
Abstract
The relationship between the number of larvae inoculated and filarial infection outcome is an important fundamental and epidemiological issue. Our study was carried out with BALB/c mice infected with the filaria Litomosoides sigmodontis. For the first time, an immunological analysis of infection with various doses was studied in parallel with parasitological data. Mice were inoculated with 200, 60 or 25 infective larvae (third stage larvae, L3), and monitored over 80 days. At 60 h post-inoculation the immune response was stronger in the 200 L3 group than the 25 L3 group. Cells from lymph nodes draining the site of inoculation proliferated intensely and produced large amounts of IL-5 and IL-4. In the pleural cavity, leukocyte populations accumulated earlier and in larger quantities. IgG1, IL-4 and IL-10 serum concentrations were transiently higher. During the first 10 days the worm recovery rates were identical in all groups, but decreased thereafter in the 200 L3 group. In this group, the development of the worms was altered, with reduced lengths, diminished intra-uterine production of microfilariae and abnormalities of male copulatory organs. Whereas mice inoculated with 25 L3 became microfilaraemic, only one third reached patency in the 200 L3 group. However, detrimental effects of high numbers of worms are not seen in studies using different inoculation protocols. This suggests that the very early events determine subsequent immune response and infection outcome rather than competitive interactions between the worms.
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Affiliation(s)
- Simon Babayan
- Parasitologie Comparée et Modèles expérimentaux associé à INSERM U567 et Ecole Pratique des Hautes Etudes, Muséum National d'Histoire Naturelle, 61 rue Buffon, 75213, Paris Cedex 05, France
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40
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Babayan S, Ungeheuer MN, Martin C, Attout T, Belnoue E, Snounou G, Rénia L, Korenaga M, Bain O. Resistance and susceptibility to filarial infection with Litomosoides sigmodontis are associated with early differences in parasite development and in localized immune reactions. Infect Immun 2004; 71:6820-9. [PMID: 14638768 PMCID: PMC308919 DOI: 10.1128/iai.71.12.6820-6829.2003] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In order to understand natural resistance to filariasis, we compared Litomosoides sigmodontis primary infection of C57BL/6 mice, which eliminate the worms before patency, and BALB/c mice, in which worms complete their development and produce microfilariae. Our analysis over the first month of infection monitoredmigration of the infective larvae from the lymph nodes to the pleural cavity, where the worms settle. Although immune responses from the mouse strains differed from the outset, the duration of lymphatic migration (4 days) and filarial recovery rates were similar, thus confirming that the proportion of larvae that develop in the host species upon infection is not influenced by host genetic variability. The majority of worms reached the adult stage in both mouse strains; however, worm growth and molting were retarded in resistant C57BL/6 mice. Surprisingly, the only immune responses detected at 60 h postinfection occurred in the susceptible mice and only upon stimulation of cells from lymph nodes draining the inoculation site with infective larva extract: massive production of interleukin-6 (IL-6) and IL-5 (the latter cytokine was previously suspected to have an effect on L. sigmodontis growth). However, between days 10 and 30 postinfection, extraordinarily high levels of type 1 and type 2 cytokines and expansion of pleural leukocyte infiltration were seen in the resistant C57BL/6 mice, explaining the destruction of worms later. Our results suggest that events early in the infection determine susceptibility or resistance to subsequent microfilarial production and a parasite strategy to use specific immune responses to its own benefit.
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Affiliation(s)
- Simon Babayan
- Parasitologie Comparée et Modèles Expérimentaux, Associé à INSERM U567, and Ecole Pratique des Hautes Etudes, Muséum National d'Histoire Naturelle, Paris, France
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41
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Abstract
There has been a prevailing perception that Th1 and Th2 immune responses induce antagonistic immune effector mechanisms during an infection. We investigated the role of the Th1 cytokine gamma interferon (IFN-gamma) and the Th2 cytokine interleukin-5 (IL-5) in murine filariasis infections with the rodent filarial nematode Litomosoides sigmodontis with regard to immune responses to the parasite. Earlier data showed an important role for IL-5 and IFN-gamma in effective immune responses to filarial infection. Therefore, in this study it was asked whether IL-5 and IFN-gamma act synergistically or antagonistically. Indeed, IL-5 as well as IFN-gamma knockout (KO) mice show a higher worm load than the wild-type controls. IFN-gamma/IL-5 double-KO mice had a significantly higher worm load than any of the single-KO mice, suggesting a synergism between IFN-gamma and IL-5 in controlling worm infection. Neutrophils are known to play an important role for the containment and encapsulation process of the worms. In infected IFN-gamma KO, IL-5 KO, and IFN-gamma/IL-5 double-KO mice, neutrophils were significantly reduced in chemotactic activity levels compared to controls. In addition, the level of phagocytosis activity of neutrophils from IFN-gamma/IL-5 double-KO mice was further decreased in comparison to that of the single-KO mice. Levels of tumor necrosis factor alpha, which is an important factor for neutrophil activation, were found to be reduced in macrophages from KO mice. In conclusion, these results argue for immune effector mechanisms in murine filarial infection that are dependent on both IFN-gamma and IL-5. Synergistic effects of the two cytokines may be mediated, at least in part, by neutrophils for the control of adult worms.
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Affiliation(s)
- Michael Saeftel
- Bernhard Nocht Institute for Tropical Medicine, Department of Helminthology, 20359 Hamburg, Germany
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42
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Xie ZY, Pan SX, Lu XG, Mai FZ, Liao N, He WT, Yang XC, Yang YC. [Surveillance of filariasis in some vulnerable areas in Guangxi after filariasis elimination]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2003; 18:354-5. [PMID: 12567614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To explore the measures for continuing surveillance of filariasis. METHODS Selecting some vulnerable spots for focal surveillance, double-slide biood sampling for microfilaria examination, dissecting vectors for detecting the mosquitoes infected with filarial larva, using IFAT for detecting antifilarial antibody. RESULTS 27,938 persons were examined for microfilaria and 4,454 mosquitoes were dissected for filaria larva, all were negative. 3,606 serum samples were examined for antifilarial antibody average positive rate was 1.35%(0.39-4.97%). CONCLUSION The results of surveillance showed that the achievement of filariasis control in Guangxi after filariasis elimination is consolidated.
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Affiliation(s)
- Z Y Xie
- Guangxi Institute of Parasitic Disease Control, Nanning 530021
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43
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Abstract
Thermostable alpha-amylase from B. licheniformis has been conjugated with high efficiency to goat antibodies against human, mouse, and rabbit immunoglobulins to prepare second-step reagents which can be used in Enzyme Linked Immunosorbent Assays (ELISA). Various conjugation methods, such as one- and two-step glutaraldehyde coupling and cross-linking, using heterobifunctional reagents such as sulfosuccinimidyl-4-(N-maleimidomethyl)-cyclohexane-1-carbonate (sulfo-SMCC) and N-succinimidyl-S-acetylthioacetate (SATA), yielded active alpha-amylase labeled second antibodies. Such conjugates had molecular sizes ranging between 200-300 kDa. Filter sterilized solutions of conjugates, when stored at 37 degrees C for two weeks, retained 32% of their biological activity and were thermostable even after keeping for 1 h at 90 degrees C.
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Affiliation(s)
- Sarita Nanda
- Department of Biochemistry, Daulat Ram College, Delhi, India.
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44
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Abstract
Cystatins of parasitic nematodes are well-described pathogenicity factors which contribute to downregulation of T-cell proliferation of their hosts and induce anti-inflammatory cytokine responses. We compared the immunomodulatory effects of two cystatins of the filarial nematodes Onchocerca volvulus and Acanthocheilonema viteae with two homologous proteins of the free-living nematode Caenorhabditis elegans. Like filarial cystatins, the C. elegans cystatins (rCysele1 and rCysele2) possessed domains relevant for inhibition of papain-like proteases and were biologically active inhibitors of human cathepsins B, L, and S. However, the inhibition of cathepsin B by C. elegans cystatin was much stronger. C. elegans cystatins lacked a domain involved in inhibition of legumain-like proteases that was present in O. volvulus cystatin. Filarial cystatins suppressed the proliferation of human peripheral blood mononuclear cells (PBMC) and murine spleen cells, while the C. elegans cystatins had this effect to a much lesser extent. Whereas filarial cystatins markedly increased the production of interleukin (IL)-10, C. elegans cystatins increased the production of IL-12 and gamma interferon (IFN-gamma) by human PBMC. The cystatins of both the filariae and C. elegans induced an upregulation of inducible nitric oxide by IFN-gamma-stimulated murine macrophages. These data suggest that filarial cystatins but not the C. elegans cystatins downregulate proliferative responses of host cells due to characteristics which might reflect an adaptation of filariae to their parasitic life style.
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Affiliation(s)
- Peter Schierack
- Department of Molecular Parasitology, Humboldt University, Berlin, Germany
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45
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Abstract
The traditional method of diagnosing filarial infections is to examine blood or skin samples for microfilariae and for many this is still the standard procedure. However, since the present global campaign to eliminate lymphatic filariasis new diagnostic tools have emerged like PCR, antigen detection using finger-prick blood taken during the day and ultrasound to visualize adult worms. The last two can be applied in endemic countries with limited resources and enable the detection of early infections. As well as their value in control schemes, the latter is particularly important for the individual since recent research has shown that damage is usually caused long before symptoms appear. The usefulness in different situations and the advantages and disadvantages of the various new tools for diagnosis of lymphatic filariasis are discussed. For loiasis, immunodiagnostic methods have not been very successful but repetitive DNA sequences in the Loa genome have been found to be species specific. Techniques based on them are particularly useful for diagnosing cases of occult infection without microfilaraemia. There have been no advances in the diagnosis of Mansonella perstans but both immunodiagnostic and PCR tests show promise in differentiating M. streptocerca, and the latter in differentiating M.ozzardi, from Onchocerca. In addition to the human filariae, the dog parasites Dirofilaria immitis and D. repens can also occur in humans but do not produce microfilariae in them. ELISAs and PCR probes have been devised and can usefully differentiate between pulmonary dirofilariasis and lung cancer.
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Affiliation(s)
- Michael Walther
- Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, University of Oxford, Old Road, Headington, Oxford OX3 7LJ, UK
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46
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Le Goff L, Lamb TJ, Graham AL, Harcus Y, Allen JE. IL-4 is required to prevent filarial nematode development in resistant but not susceptible strains of mice. Int J Parasitol 2002; 32:1277-84. [PMID: 12204227 DOI: 10.1016/s0020-7519(02)00125-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The murine Litomosoides sigmodontis model of filarial infection provides the opportunity to elucidate the immunological mechanisms that determine whether these nematode parasites can establish a successful infection or are rejected by the mammalian host. BALB/c mice are fully susceptible to L. sigmodontis infection and can develop patent infection, with the microfilarial stage circulating in the bloodstream. In contrast, mice on the C57BL background are largely resistant to the infection and never produce a patent infection. In this study, we used IL-4 deficient mice on the C57BL/6 background to address the role of IL-4 in the development of L. sigmodontis parasites in a resistant host. Two months after infection, adult worm recovery and the percentage of microfilaraemic mice in infected IL-4 deficient mice were comparable with those of the susceptible BALB/c mice while, as expected, healthy adults were not recovered from wild type C57BL/6 mice. The cytokine and antibody responses reveal that despite similar parasitology the two susceptible strains (BALB/c and IL-4 deficient C57BL/6) have markedly different immune responses: wild type BALB/c mice exhibit a strong Th2 immune response and the IL-4 deficient C57BL/6 mice exhibit a Th1 response. We also excluded a role for antibodies in resistance through infection of B-cell deficient C57BL/6 mice. Our data suggest that the mechanisms that determine parasite clearance in a resistant/non-permissive host are Th2 dependent but that in a susceptible/permissive host, the parasite can develop in the face of a Th2 dominated response.
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Affiliation(s)
- Laetitia Le Goff
- Institute of Cell, Animal and Population Biology, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh, UK
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47
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Bazzocchi C, Ceciliani F, Brattig N. [Bacterial symbionts (Wolbachia) of filarial nematodes: implications for the treatment and pathology of filariasis]. Ann Ist Super Sanita 2002; 37:265-73. [PMID: 11758285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Filarial nematodes harbour intracellular, Gram-negative bacteria belonging to the genus Wolbachia. These bacteria have been observed in various species of filariae, including the main filariasis agents of humans and animals. It has been suggested that Wolbachia could play an important role in the biology of filarial nematodes and could be implicated in the pathogenesis of filarial diseases. Wolbachia could thus represent a target for the control of filariasis and key to the understanding of these diseases. Indeed, in various species of filariae, tetracycline treatments have been shown both to reduce/eliminate the Wolbachia population and to determine detrimental effects on the nematodes. In addition, proteins of Wolbachia have been shown to determine specific IgG responses in animals infected by filariae and some Wolbachia molecules (e.g. LPS) have been shown to stimulate innate-immunity responses (e.g. production of cytokines such as IL1, IL6, IL10, TNF-alpha and IFN-gamma by macrophages).
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Affiliation(s)
- C Bazzocchi
- Dipartimento di Patologia Animale, Igiene e Sanità Pubblica Veterinaria, Sezione di Patologia Generale e Parassitologia, Università degli Studi, Milano
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48
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Harnett MM, Harnett W. Antigen receptor signaling is subverted by an immunomodulatory product secreted by a filarial nematode. Arch Immunol Ther Exp (Warsz) 2002; 49:263-9. [PMID: 11726028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
ES-62 is a phosphorylcholine (PC)-containing glycoprotein secreted by the rodent filarial nematode Acanthocheilonema viteae which is able to inhibit antigen receptor-stimulated proliferation of B and T lymphocytes in vitro and in vivo. The active component of ES-62 appears to be PC, as the results obtained with ES-62 are broadly mimicked by PC conjugated to bovine serum albumin or PC alone. Such desensitization of lymphocyte responsiveness appears to reflect an uncoupling of the antigen receptors from key intracellular proliferative signaling events, such as the phosphoinositide-3-kinase, protein kinase C and Ras mitogen-activating protein kinase pathways. ES-62 mediates such immunomodulatory effects at concentrations equivalent to those found for PC-containing molecules in the bloodstream of parasitized humans and, thus, ES-62 provides a model system for dissecting the mechanisms of immune evasion induced by related PC-containing glycoproteins expressed by human filarial nematodes.
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Affiliation(s)
- M M Harnett
- Department of Immunology, University of Glasgow, UK.
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Korten S, Volkmann L, Saeftel M, Fischer K, Taniguchi M, Fleischer B, Hoerauf A. Expansion of NK cells with reduction of their inhibitory Ly-49A, Ly-49C, and Ly-49G2 receptor-expressing subsets in a murine helminth infection: contribution to parasite control. J Immunol 2002; 168:5199-206. [PMID: 11994476 DOI: 10.4049/jimmunol.168.10.5199] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Natural killer cell-associated direct cytotoxicity and cytokine production are crucial mechanisms for early innate host resistance against viruses, bacteria, or protozoa. The engagement of inhibitory NK cell receptors can influence host responses to viruses. However, these receptors have not been investigated to date in parasitic infections, and little is known about the role of NK cells in the defense against helminths. Therefore, we have correlated the frequencies of cells expressing the pan-NK marker DX5 and subsets bearing inhibitory Ly-49 receptors with worm survival and cytokine production during infection with Litomosoides sigmodontis in BALB/c mice (H2(d)), the only fully permissive model of filariasis. A marked influx of DX5(+)/CD3(-) NK cells and DX5(+)/CD3(+) T cells into the pleural cavity, where the parasites were located, was observed. The frequency of pleural NK cells expressing the H2(d)-reactive inhibitory receptors Ly-49A, Ly-49C, or Ly-49G2 declined most strongly compared with spleen and blood. In the peripheral blood, longitudinal analysis revealed an early and stable reduction of Ly-49C(+) and Ly-49G2(+) NK cells, a subsequent significant increase of the entire NK cell and DX5(+)/CD3(+) T cell populations, and a reduction in the Ly-49A(+) subset. The in vivo depletion of NK cells strongly enhanced the worm load and influenced IL-4 and IL-5 plasma levels. These data demonstrate a new role for NK cells in the host defense against filariae and, for the first time, alterations of Ly-49 receptor-expressing NK cell subsets in a parasitic infection.
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MESH Headings
- Animals
- Antigens, Ly
- Biomarkers/blood
- Carrier Proteins/antagonists & inhibitors
- Carrier Proteins/biosynthesis
- Carrier Proteins/blood
- Carrier Proteins/physiology
- Cell Division/immunology
- Cytokines/biosynthesis
- Cytotoxicity, Immunologic
- Filariasis/immunology
- Filariasis/parasitology
- Filariasis/prevention & control
- Filarioidea/growth & development
- Filarioidea/immunology
- Immunophenotyping
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Killer Cells, Natural/parasitology
- Lectins, C-Type
- Lymphocyte Activation
- Lymphocyte Count
- Lymphocyte Depletion
- Membrane Glycoproteins/antagonists & inhibitors
- Membrane Glycoproteins/biosynthesis
- Membrane Glycoproteins/blood
- Membrane Glycoproteins/physiology
- Membrane Proteins/antagonists & inhibitors
- Membrane Proteins/biosynthesis
- Membrane Proteins/blood
- Membrane Proteins/physiology
- Mice
- Mice, Inbred BALB C
- Microfilariae/growth & development
- Microfilariae/immunology
- Receptors, Immunologic/antagonists & inhibitors
- Receptors, Immunologic/biosynthesis
- Receptors, Immunologic/blood
- Receptors, Immunologic/physiology
- Receptors, NK Cell Lectin-Like
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- T-Lymphocyte Subsets/parasitology
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Affiliation(s)
- Simone Korten
- Department of Medical Microbiology and Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
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50
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Pfaff AW, Schulz-Key H, Soboslay PT, Taylor DW, MacLennan K, Hoffmann WH. Litomosoides sigmodontis cystatin acts as an immunomodulator during experimental filariasis. Int J Parasitol 2002; 32:171-8. [PMID: 11812494 DOI: 10.1016/s0020-7519(01)00350-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
During chronic filariasis, parasite-specific cellular responsiveness is profoundly down-regulated. Cystatins, a group of cysteine protease inhibitors, have been implicated in this suppressive activity. In an attempt to investigate the effects of cystatins in vivo, we isolated and expressed a 14 kDa protein of the rodent filaria Litomosoides sigmodontis with substantial homologies to cystatins from human pathogenic filariae. Cystatin was detected in antigen preparations of several developmental stages of L. sigmodontis, as well as in the supernatants of in vitro cultured adult worms. On closer examination, L. sigmodontis cystatin (Ls-Cystatin) migrated as two separate bands at 14 and 15 kDa. When cystatin was introduced into the peritoneal cavity of C57BL/6 mice via micro-osmotic pumps, the production of nitric oxide was profoundly reduced upon microfilarial challenge and, at the same time, synthesis of TNF-alpha mRNA became up-regulated. Furthermore, antigen-specific proliferative response of spleen cells to circulating L. sigmodontis microfilariae was significantly diminished in the presence of cystatin, whereas the antibody production was not suppressed. In vaccination trials, using the L. sigmodontis/BALB/c mouse model of filariasis, L. sigmodontis cystatin did not generate protective effects in terms of adult worm recovery, however, lower numbers of patent infections, i.e. less infections with microfilaraemia were observed in vaccinated animals. These results suggested that cystatin acts as an immunomodulatory molecule during the course of a filarial infection, and its neutralisation might contribute to generate protective immune responses.
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Affiliation(s)
- Alexander W Pfaff
- Institute for Tropical Medicine, University of Tubingen, Wilhelmstrasse 27, 72074, Tubingen, Germany.
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