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Valigurová A, Kolářová I. Unrevealing the Mystery of Latent Leishmaniasis: What Cells Can Host Leishmania? Pathogens 2023; 12:pathogens12020246. [PMID: 36839518 PMCID: PMC9967396 DOI: 10.3390/pathogens12020246] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023] Open
Abstract
Leishmania spp. (Kinetoplastida) are unicellular parasites causing leishmaniases, neglected tropical diseases of medical and veterinary importance. In the vertebrate host, Leishmania parasites multiply intracellularly in professional phagocytes, such as monocytes and macrophages. However, their close relative with intracellular development-Trypanosoma cruzi-can unlock even non-professional phagocytes. Since Leishmania and T. cruzi have similar organelle equipment, is it possible that Leishmania can invade and even proliferate in cells other than the professional phagocytes? Additionally, could these cells play a role in the long-term persistence of Leishmania in the host, even in cured individuals? In this review, we provide (i) an overview of non-canonical Leishmania host cells and (ii) an insight into the strategies that Leishmania may use to enter them. Many studies point to fibroblasts as already established host cells that are important in latent leishmaniasis and disease epidemiology, as they support Leishmania transformation into amastigotes and even their multiplication. To invade them, Leishmania causes damage to their plasma membrane and exploits the subsequent repair mechanism via lysosome-triggered endocytosis. Unrevealing the interactions between Leishmania and its non-canonical host cells may shed light on the persistence of these parasites in vertebrate hosts, a way to control latent leishmaniasis.
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Affiliation(s)
- Andrea Valigurová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
- Correspondence: (A.V.); (I.K.)
| | - Iva Kolářová
- Department of Parasitology, Faculty of Science, Charles University, Albertov 6, 128 44 Prague, Czech Republic
- Correspondence: (A.V.); (I.K.)
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Parlar YE, Ayar SN, Cagdas D, Balaban YH. Liver immunity, autoimmunity, and inborn errors of immunity. World J Hepatol 2023; 15:52-67. [PMID: 36744162 PMCID: PMC9896502 DOI: 10.4254/wjh.v15.i1.52] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/23/2022] [Accepted: 12/23/2022] [Indexed: 01/16/2023] Open
Abstract
The liver is the front line organ of the immune system. The liver contains the largest collection of phagocytic cells in the body that detect both pathogens that enter through the gut and endogenously produced antigens. This is possible by the highly developed differentiation capacity of the liver immune system between self-antigens or non-self-antigens, such as food antigens or pathogens. As an immune active organ, the liver functions as a gatekeeping barrier from the outside world, and it can create a rapid and strong immune response, under unfavorable conditions. However, the liver's assumed immune status is anti-inflammatory or immuno-tolerant. Dynamic interactions between the numerous populations of immune cells in the liver are key for maintaining the delicate balance between immune screening and immune tolerance. The anatomical structure of the liver can facilitate the preparation of lymphocytes, modulate the immune response against hepatotropic pathogens, and contribute to some of its unique immunological properties, particularly its capacity to induce antigen-specific tolerance. Since liver sinusoidal endothelial cell is fenestrated and lacks a basement membrane, circulating lymphocytes can closely contact with antigens, displayed by endothelial cells, Kupffer cells, and dendritic cells while passing through the sinusoids. Loss of immune tolerance, leading to an autoaggressive immune response in the liver, if not controlled, can lead to the induction of autoimmune or autoinflammatory diseases. This review mentions the unique features of liver immunity, and dysregulated immune responses in patients with autoimmune liver diseases who have a close association with inborn errors of immunity have also been the emphases.
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Affiliation(s)
- Yavuz Emre Parlar
- Department of Gastroenterology, Hacettepe University Faculty of Medicine, Ankara 06100, Turkey
| | - Sefika Nur Ayar
- Department of Internal Medicine, Hacettepe University Faculty of Medicine, Ankara 06100, Turkey
| | - Deniz Cagdas
- Department of Pediatric Immunology, Hacettepe University Ihsan Dogramaci Children's Hospital, Ankara 06100, Turkey
| | - Yasemin H Balaban
- Department of Gastroenterology, Hacettepe University Faculty of Medicine, Ankara 06100, Turkey
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3
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Osero BO, Cele Z, Aruleba RT, Maine RA, Ozturk M, Lutz MB, Brombacher F, Hurdayal R. Interleukin-4 Responsive Dendritic Cells Are Dispensable to Host Resistance Against Leishmania mexicana Infection. Front Immunol 2022; 12:759021. [PMID: 35154068 PMCID: PMC8831752 DOI: 10.3389/fimmu.2021.759021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 12/29/2021] [Indexed: 11/13/2022] Open
Abstract
IL-4 and IL-13 cytokines have been associated with a non-healing phenotype in murine leishmaniasis in L. mexicana -infected BALB/c mice as demonstrated in IL-4−/−, IL-13−/− and IL-4Rα-/- global knockout mouse studies. However, it is unclear from the studies which cell-type-specific IL-4/IL-13 signaling mediates protection to L. mexicana. Previous studies have ruled out a role for IL-4-mediated protection on CD4+ T cells during L. mexicana infections. A candidate for this role may be non-lymphocyte cells, particularly DCs, as was previously shown in L. major infections, where IL-4 production drives dendritic cell-IL-12 production thereby mediating a type 1 immune response. However, it is unclear if this IL-4-instruction of type 1 immunity also occurs in CL caused by L. mexicana, since the outcome of cutaneous leishmaniasis often depends on the infecting Leishmania species. Thus, BALB/c mice with cell-specific deletion of the IL-4Rα on CD11c+ DCs (CD11ccreIL-4Rα-/lox) were infected with L. mexicana promastigotes in the footpad and the clinical phenotype, humoral and cellular immune responses were investigated, compared to the littermate control. Our results show that CL disease progression in BALB/c mice is independent of IL-4Rα signaling on DCs as CD11ccreIL-4Rα-/lox mice had similar footpad lesion progression, parasite loads, humoral responses (IgE, IgG1, IgG 2a/b), and IFN-γ cytokine secretion in comparison to littermate controls. Despite this comparable phenotype, surprisingly, IL-4 production in CD11ccreIL-4Rα-/lox mice was significantly increased with an increasing trend of IL-13 when compared to littermate controls. Moreover, the absence of IL-4Rα signaling did not significantly alter the frequency of CD4 and CD8 lymphocytes nor their activation, or memory phenotype compared to littermate controls. However, these populations were significantly increased in CD11ccreIL-4Rα-/lox mice due to greater total cell infiltration into the lymph node. A similar trend was observed for B cells whereas the recruitment of myeloid populations (macrophages, DCs, neutrophils, and Mo-DCs) into LN was comparable to littermate IL-4Rα-/lox mice. Interestingly, IL-4Rα-deficient bone marrow-derived dendritic cells (BMDCs), stimulated with LPS or L. mexicana promastigotes in presence of IL-4, showed similar levels of IL-12p70 and IL-10 to littermate controls highlighting that IL-4-mediated DC instruction was not impaired in response to L. mexicana. Similarly, IL-4 stimulation did not affect the maturation or activation of IL-4Rα-deficient BMDCs during L. mexicana infection nor their effector functions in production of nitrite and arginine-derived metabolite (urea). Together, this study suggests that IL-4 Rα signaling on DCs is not key in the regulation of immune-mediated protection in mice against L. mexicana infection.
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Affiliation(s)
- Bernard Ong’ondo Osero
- Division of Immunology, Department of Pathology, Faculty of Health Sciences, Institute of Infectious Diseases and Molecular Medicine (IDM), South African Medical Research Council (SAMRC) on Immunology of Infectious Diseases, University of Cape Town, Cape Town, South Africa
- International Centre for Genetic Engineering and Biotechnology, Cape Town Component, Cape Town, South Africa
- Faculty of Health Sciences, Wellcome Centre for Infectious Diseases Research in Africa (CIDRI), Institute of Infectious Diseases and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Zama Cele
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
| | - Raphael Taiwo Aruleba
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
| | - Rebeng A. Maine
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
| | - Mumin Ozturk
- Division of Immunology, Department of Pathology, Faculty of Health Sciences, Institute of Infectious Diseases and Molecular Medicine (IDM), South African Medical Research Council (SAMRC) on Immunology of Infectious Diseases, University of Cape Town, Cape Town, South Africa
- International Centre for Genetic Engineering and Biotechnology, Cape Town Component, Cape Town, South Africa
- Faculty of Health Sciences, Wellcome Centre for Infectious Diseases Research in Africa (CIDRI), Institute of Infectious Diseases and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
| | - Manfred B. Lutz
- Institute of Virology and Immunobiology, University of Würzburg, Würzburg, Germany
| | - Frank Brombacher
- Division of Immunology, Department of Pathology, Faculty of Health Sciences, Institute of Infectious Diseases and Molecular Medicine (IDM), South African Medical Research Council (SAMRC) on Immunology of Infectious Diseases, University of Cape Town, Cape Town, South Africa
- International Centre for Genetic Engineering and Biotechnology, Cape Town Component, Cape Town, South Africa
- Faculty of Health Sciences, Wellcome Centre for Infectious Diseases Research in Africa (CIDRI), Institute of Infectious Diseases and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
- *Correspondence: Frank Brombacher, ; Ramona Hurdayal,
| | - Ramona Hurdayal
- Division of Immunology, Department of Pathology, Faculty of Health Sciences, Institute of Infectious Diseases and Molecular Medicine (IDM), South African Medical Research Council (SAMRC) on Immunology of Infectious Diseases, University of Cape Town, Cape Town, South Africa
- International Centre for Genetic Engineering and Biotechnology, Cape Town Component, Cape Town, South Africa
- Faculty of Health Sciences, Wellcome Centre for Infectious Diseases Research in Africa (CIDRI), Institute of Infectious Diseases and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
- *Correspondence: Frank Brombacher, ; Ramona Hurdayal,
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Rostami MN, Khamesipour A. Potential biomarkers of immune protection in human leishmaniasis. Med Microbiol Immunol 2021; 210:81-100. [PMID: 33934238 PMCID: PMC8088758 DOI: 10.1007/s00430-021-00703-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 03/22/2021] [Indexed: 12/30/2022]
Abstract
Leishmaniasis is a vector-borne neglected tropical disease endemic in over 100 countries around the world. Available control measures are not always successful, therapeutic options are limited, and there is no vaccine available against human leishmaniasis, although several candidate antigens have been evaluated over the last decades. Plenty of studies have aimed to evaluate the immune response development and a diverse range of host immune factors have been described to be associated with protection or disease progression in leishmaniasis; however, to date, no comprehensive biomarker(s) have been identified as surrogate marker of protection or exacerbation, and lack of enough information remains a barrier for vaccine development. Most of the current understanding of the role of different markers of immune response in leishmaniasis has been collected from experimental animal models. Although the data generated from the animal models are crucial, it might not always be extrapolated to humans. Here, we briefly review the events during Leishmania invasion of host cells and the immune responses induced against Leishmania in animal models and humans and their potential role as a biomarker of protection against human leishmaniasis.
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Affiliation(s)
| | - Ali Khamesipour
- Center for Research and Training in Skin Diseases and Leprosy, Tehran University of Medical Sciences, 14155-6383, Tehran, Iran.
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da Silva GAV, Mesquita TG, Souza VC, Junior JDES, Gomes de Souza ML, Talhari AC, Talhari S, Naveca FG, Ramasawmy R. A Single Haplotype of IFNG Correlating With Low Circulating Levels of Interferon-γ Is Associated With Susceptibility to Cutaneous Leishmaniasis Caused by Leishmania guyanensis. Clin Infect Dis 2021; 71:274-281. [PMID: 31722386 DOI: 10.1093/cid/ciz810] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 08/22/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Interferon-γ (IFN-γ) plays an important role in the control of Leishmania infection. Blockade of IFN-γ signaling in mice increases lesion size and parasite load. In endemic areas of Leishmaniasis, only a fraction of the population develop the disease. This suggest that host genetics may play a role in this response. We investigated whether single nucleotide polymorphisms (SNPs) in IFNG may be associated with elevated or decrease risk in the development of cutaneous leishmaniasis (CL). METHODS We assessed 9 SNP and cytosine-adenine (CA) repeats in IFNG by nucleotide sequencing in 647 patients with CL caused by Leishmania guyanensis and 629 controls. Circulating plasma IFN-γ levels were also assayed in 400 patients with CL and 400 controls. RESULTS The rs2069705TT genotype is associated with elevated risk of developing CL compared with the rs2069705CC genotype (OR, 1.7; 95% CI, 1.3-2.4; P = .0008). There is a 70% chance that this genotype raises the risk of developing CL. In a dominant model, carriers of the rs2069705T allele compared with the rs2069705CC genotype showed a 50% (range, 20-100%) increased risk of developing CL (OR, 1.5; 95% CI, 1.2-2.0; P = .0004). Haplotype analysis showed 1 haplotype (H1) associated with low levels of IFN-γ presented an increased risk of 60% of developing CL (OR, 1.6; 95% CI, 1.3-1.9; P = 5 × 10-5) compared with non-H1. CONCLUSIONS IFNG variant rs2069705 seems to be a genetic modifier of clinical outcome of Leishmania infection; individuals with the H1 haplotype, associated with low levels of IFN-γ, have a 60% risk of developing CL.
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Affiliation(s)
- George A V da Silva
- Programa de Pos-Graduação em Imunologia Básica e Aplicada, Universidade Federal do Amazonas, Amazonas, Manaus, Brazil
| | - Tirza G Mesquita
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Amazonas, Manaus, Brazil
| | - Victor C Souza
- Instituto Leônidas e Maria Deane, FIOCRUZ Amazônia, Amazonas, Manaus, Brazil
| | - José do Espírito Santo Junior
- Programa de Pos-Graduação em Imunologia Básica e Aplicada, Universidade Federal do Amazonas, Amazonas, Manaus, Brazil
| | | | | | - Sinésio Talhari
- Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Amazonas, Brazil.,Faculdade de Medicina, Universidade Nilton Lins, Amazonas, Manaus, Brazil
| | - Felipe G Naveca
- Instituto Leônidas e Maria Deane, FIOCRUZ Amazônia, Amazonas, Manaus, Brazil
| | - Rajendranath Ramasawmy
- Programa de Pos-Graduação em Imunologia Básica e Aplicada, Universidade Federal do Amazonas, Amazonas, Manaus, Brazil.,Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Amazonas, Brazil.,Faculdade de Medicina, Universidade Nilton Lins, Amazonas, Manaus, Brazil
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6
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Martínez-López M, Soto M, Iborra S, Sancho D. Leishmania Hijacks Myeloid Cells for Immune Escape. Front Microbiol 2018; 9:883. [PMID: 29867798 PMCID: PMC5949370 DOI: 10.3389/fmicb.2018.00883] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 04/17/2018] [Indexed: 12/23/2022] Open
Abstract
Protozoan parasites of the Leishmania genus are the causative agents of leishmaniasis, a group of neglected tropical diseases whose clinical manifestations vary depending on the infectious Leishmania species but also on host factors. Recognition of the parasite by host myeloid immune cells is a key to trigger an effective Leishmania-specific immunity. However, the parasite is able to persist in host myeloid cells by evading, delaying and manipulating host immunity in order to escape host resistance and ensure its transmission. Neutrophils are first in infiltrating infection sites and could act either favoring or protecting against infection, depending on factors such as the genetic background of the host or the parasite species. Macrophages are the main host cells where the parasites grow and divide. However, macrophages are also the main effector population involved in parasite clearance. Parasite elimination by macrophages requires the priming and development of an effector Th1 adaptive immunity driven by specific subtypes of dendritic cells. Herein, we will provide a comprehensive outline of how myeloid cells regulate innate and adaptive immunity against Leishmania, and the mechanisms used by the parasites to promote their evasion and sabotage. Understanding the interactions between Leishmania and the host myeloid cells may lead to the development of new therapeutic approaches and improved vaccination to leishmaniases, an important worldwide health problem in which current therapeutic or preventive approaches are limited.
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Affiliation(s)
- María Martínez-López
- Immunobiology Laboratory, Fundación Centro Nacional de Investigaciones Cardiovasculares "Carlos III", Madrid, Spain
| | - Manuel Soto
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa - Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain
| | - Salvador Iborra
- Immunobiology Laboratory, Fundación Centro Nacional de Investigaciones Cardiovasculares "Carlos III", Madrid, Spain.,Department of Immunology, Complutense University School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - David Sancho
- Immunobiology Laboratory, Fundación Centro Nacional de Investigaciones Cardiovasculares "Carlos III", Madrid, Spain
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Dendritic Cells and Leishmania Infection: Adding Layers of Complexity to a Complex Disease. J Immunol Res 2016; 2016:3967436. [PMID: 26904694 PMCID: PMC4745329 DOI: 10.1155/2016/3967436] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 12/28/2015] [Indexed: 01/21/2023] Open
Abstract
Leishmaniasis is a group of neglected diseases whose clinical manifestations depend on factors from the host and the pathogen. It is an important public health problem worldwide caused by the protozoan parasite from the Leishmania genus. Cutaneous Leishmaniasis (CL) is the most frequent form of this disease transmitted by the bite of an infected sandfly into the host skin. The parasites can be uptook and/or recognized by macrophages, neutrophils, and/or dendritic cells (DCs). Initially, DCs were described to play a protective role in activating the immune response against Leishmania parasites. However, several reports showed a dichotomic role of DCs in modulating the host immune response to susceptibility or resistance in CL. In this review, we discuss (1) the interactions between DCs and parasites from different species of Leishmania and (2) the crosstalk of DCs and other cells during CL infection. The complexity of these interactions profoundly affects the adaptive immune response and, consequently, the disease outcome, especially from Leishmania species of the New World.
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8
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Liévin-Le Moal V, Loiseau PM. Leishmania hijacking of the macrophage intracellular compartments. FEBS J 2015; 283:598-607. [PMID: 26588037 DOI: 10.1111/febs.13601] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 11/08/2015] [Accepted: 11/13/2015] [Indexed: 12/15/2022]
Abstract
Leishmania spp., transmitted to humans by the bite of the sandfly vector, are responsible for the three major forms of leishmaniasis, cutaneous, diffuse mucocutaneous and visceral. Leishmania spp. interact with membrane receptors of neutrophils and macrophages. In macrophages, the parasite is internalized within a parasitophorous vacuole and engages in a particular intracellular lifestyle in which the flagellated, motile Leishmania promastigote metacyclic form differentiates into non-motile, metacyclic amastigote form. This phenomenon is induced by Leishmania-triggered events leading to the fusion of the parasitophorous vacuole with vesicular members of the host cell endocytic pathway including recycling endosomes, late endosomes and the endoplasmic reticulum. Maturation of the parasitophorous vacuole leads to the intracellular proliferation of the Leishmania amastigote forms by acquisition of host cell nutrients while escaping host defense responses.
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Affiliation(s)
- Vanessa Liévin-Le Moal
- Anti-Parasitic Chemotherapy, Faculté de Pharmacie, CNRS, UMR 8076 BioCIS, Châtenay-Malabry, France.,Université Paris-Sud, Orsay, France.,Faculté de Pharmacie, Laboratory of Excellence in Research on Medication and Innovative Therapeutics (LabEx LERMIT), Châtenay-Malabry, France
| | - Philippe M Loiseau
- Anti-Parasitic Chemotherapy, Faculté de Pharmacie, CNRS, UMR 8076 BioCIS, Châtenay-Malabry, France.,Université Paris-Sud, Orsay, France.,Faculté de Pharmacie, Laboratory of Excellence in Research on Medication and Innovative Therapeutics (LabEx LERMIT), Châtenay-Malabry, France
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9
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Ashok D, Acha-Orbea H. Timing is everything: dendritic cell subsets in murine Leishmania infection. Trends Parasitol 2014; 30:499-507. [DOI: 10.1016/j.pt.2014.08.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 08/07/2014] [Accepted: 08/08/2014] [Indexed: 02/02/2023]
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10
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Ashok D, Schuster S, Ronet C, Rosa M, Mack V, Lavanchy C, Marraco SF, Fasel N, Murphy KM, Tacchini-Cottier F, Acha-Orbea H. Cross-presenting dendritic cells are required for control of Leishmania major infection. Eur J Immunol 2014; 44:1422-32. [PMID: 24643576 DOI: 10.1002/eji.201344242] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 12/27/2013] [Accepted: 02/06/2014] [Indexed: 11/08/2022]
Abstract
Leishmania major infection induces self-healing cutaneous lesions in C57BL/6 mice. Both IL-12 and IFN-γ are essential for the control of infection. We infected Jun dimerization protein p21SNFT (Batf3(-/-) ) mice (C57BL/6 background) that lack the major IL-12 producing and cross-presenting CD8α(+) and CD103(+) DC subsets. Batf3(-/-) mice displayed enhanced susceptibility with larger lesions and higher parasite burden. Additionally, cells from draining lymph nodes of infected Batf3(-/-) mice secreted less IFN-γ, but more Th2- and Th17-type cytokines, mirrored by increased serum IgE and Leishmania-specific immunoglobulin 1 (Th2 indicating). Importantly, CD8α(+) DCs isolated from lymph nodes of L. major-infected mice induced significantly more IFN-γ secretion by L. major-stimulated immune T cells than CD103(+) DCs. We next developed CD11c-diptheria toxin receptor: Batf3(-/-) mixed bone marrow chimeras to determine when the DCs are important for the control of infection. Mice depleted of Batf-3-dependent DCs from day 17 or wild-type mice depleted of cross-presenting DCs from 17-19 days after infection maintained significantly larger lesions similar to mice whose Batf-3-dependent DCs were depleted from the onset of infection. Thus, we have identified a crucial role for Batf-3-dependent DCs in protection against L. major.
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Affiliation(s)
- Devika Ashok
- Department of Biochemistry, University of Lausanne, Lausanne, Switzerland
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11
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Liu D, Uzonna JE. The early interaction of Leishmania with macrophages and dendritic cells and its influence on the host immune response. Front Cell Infect Microbiol 2012; 2:83. [PMID: 22919674 PMCID: PMC3417671 DOI: 10.3389/fcimb.2012.00083] [Citation(s) in RCA: 214] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 05/27/2012] [Indexed: 01/26/2023] Open
Abstract
The complicated interactions between Leishmania and the host antigen-presenting cells (APCs) have fundamental effects on the final outcome of the disease. Two major APCs, macrophages and dendritic cells (DCs), play critical roles in mediating resistance and susceptibility during Leishmania infection. Macrophages are the primary resident cell for Leishmania: they phagocytose and permit parasite proliferation. However, these cells are also the major effector cells to eliminate infection. The effective clearance of parasites by macrophages depends on activation of appropriate immune response, which is usually initiated by DCs. Here, we review the early interaction of APCs with Leishmania parasites and how these interactions profoundly impact on the ensuing adaptive immune response. We also discuss how the current knowledge will allow further refinement of our understanding of the interplay between Leishmania and its hosts that leads to resistance or susceptibility.
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Affiliation(s)
- Dong Liu
- Department of Immunology, University of Manitoba, Winnipeg MB, Canada
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12
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Bialecki E, Macho Fernandez E, Ivanov S, Paget C, Fontaine J, Rodriguez F, Lebeau L, Ehret C, Frisch B, Trottein F, Faveeuw C. Spleen-resident CD4+ and CD4- CD8α- dendritic cell subsets differ in their ability to prime invariant natural killer T lymphocytes. PLoS One 2011; 6:e26919. [PMID: 22066016 PMCID: PMC3204990 DOI: 10.1371/journal.pone.0026919] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 10/06/2011] [Indexed: 12/03/2022] Open
Abstract
One important function of conventional dendritic cells (cDC) is their high capacity to capture, process and present Ag to T lymphocytes. Mouse splenic cDC subtypes, including CD8α+ and CD8α− cDC, are not identical in their Ag presenting and T cell priming functions. Surprisingly, few studies have reported functional differences between CD4− and CD4+ CD8α− cDC subsets. We show that, when loaded in vitro with OVA peptide or whole protein, and in steady-state conditions, splenic CD4− and CD4+ cDC are equivalent in their capacity to prime and direct CD4+ and CD8+ T cell differentiation. In contrast, in response to α-galactosylceramide (α-GalCer), CD4− and CD4+ cDC differentially activate invariant Natural Killer T (iNKT) cells, a population of lipid-reactive non-conventional T lymphocytes. Both cDC subsets equally take up α-GalCer in vitro and in vivo to stimulate the iNKT hybridoma DN32.D3, the activation of which depends solely on TCR triggering. On the other hand, and relative to their CD4+ counterparts, CD4− cDC more efficiently stimulate primary iNKT cells, a phenomenon likely due to differential production of co-factors (including IL-12) by cDC. Our data reveal a novel functional difference between splenic CD4+ and CD4− cDC subsets that may be important in immune responses.
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Affiliation(s)
- Emilie Bialecki
- Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique (CNRS), UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1019, Lille, France
- Institut Fédératif de Recherche 142, Lille, France
| | - Elodie Macho Fernandez
- Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique (CNRS), UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1019, Lille, France
- Institut Fédératif de Recherche 142, Lille, France
| | - Stoyan Ivanov
- Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique (CNRS), UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1019, Lille, France
- Institut Fédératif de Recherche 142, Lille, France
| | - Christophe Paget
- Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique (CNRS), UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1019, Lille, France
- Institut Fédératif de Recherche 142, Lille, France
| | - Josette Fontaine
- Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique (CNRS), UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1019, Lille, France
- Institut Fédératif de Recherche 142, Lille, France
| | - Fabien Rodriguez
- Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique (CNRS), UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1019, Lille, France
- Institut Fédératif de Recherche 142, Lille, France
| | - Luc Lebeau
- Laboratoire de Conception et Application des Molécules Bioactives, Faculté de Pharmacie, CNRS, UMR 7199/Université de Strasbourg, Illkirch, France
| | - Christophe Ehret
- Laboratoire de Conception et Application des Molécules Bioactives, Faculté de Pharmacie, CNRS, UMR 7199/Université de Strasbourg, Illkirch, France
| | - Benoit Frisch
- Laboratoire de Conception et Application des Molécules Bioactives, Faculté de Pharmacie, CNRS, UMR 7199/Université de Strasbourg, Illkirch, France
| | - François Trottein
- Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique (CNRS), UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1019, Lille, France
- Institut Fédératif de Recherche 142, Lille, France
| | - Christelle Faveeuw
- Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique (CNRS), UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1019, Lille, France
- Institut Fédératif de Recherche 142, Lille, France
- * E-mail:
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13
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Neves BM, Silvestre R, Resende M, Ouaissi A, Cunha J, Tavares J, Loureiro I, Santarém N, Silva AM, Lopes MC, Cruz MT, Cordeiro da Silva A. Activation of phosphatidylinositol 3-kinase/Akt and impairment of nuclear factor-kappaB: molecular mechanisms behind the arrested maturation/activation state of Leishmania infantum-infected dendritic cells. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:2898-911. [PMID: 21037075 DOI: 10.2353/ajpath.2010.100367] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Understanding the complex interactions between Leishmania and dendritic cells (DCs) is central to the modulation of the outcome of this infection, given that an effective immune response against Leishmania is dependent on the successful activation and maturation of DCs. We report here that Leishmania infantum promastigotes successfully infect mouse bone marrow-derived DCs without triggering maturation, as shown by a failure in the up-regulation of CD40 and CD86 expression, and that parasites strongly counteract the lipopolysaccharide-triggered maturation of DCs. A small increase in interleukin (IL)-12 and IL-10 transcription and secretion and a decrease in IL-6 were observed in infected cells. This arrested DC maturation state is actively promoted by parasites because heat-killed or fixed parasites increased cytokine and costimulatory molecule expression. At a molecular level, L. infantum rapidly induced activation of phosphatidylinositol 3-kinase/Akt and extracellular signal-regulated kinase 1/2, whereas no effect was observed in the c-Jun N-terminal kinase and p38 mitogen-activated protein kinase proinflammatory pathways. Moreover, parasites actively promoted cleavage of the nuclear factor-κB p65(RelA) subunit, causing its impairment. The blockade of phosphatidylinositol 3-kinase/Akt by either treatment of bone marrow-derived DCs with wortmannin or transfection with an Akt dominant-negative mutant resulted in a strong decrease in infection rates, revealing for the first time a crucial role of this pathway on Leishmania engulfment by DCs. Overall, our data indicate that activation of Akt and impairment of nuclear factor-κB are responsible for immunogenicity subversion of L. infantum-infected DCs.
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Affiliation(s)
- Bruno Miguel Neves
- Faculdade de Farmácia, and Centro de Neurociências e Biologia Celular, Universidade de Coimbra, Coimbra, Portugal.
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14
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Regulation of the expression of nitric oxide synthase by Leishmania mexicana amastigotes in murine dendritic cells. Exp Parasitol 2010; 126:426-34. [PMID: 20659463 DOI: 10.1016/j.exppara.2010.07.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Revised: 07/10/2010] [Accepted: 07/20/2010] [Indexed: 12/28/2022]
Abstract
In mammalian hosts, Leishmania parasites are obligatory intracellular organisms that invade macrophages (M phi) and dendritic cells (DC). In M phi, the production of nitric oxide (NO) catalyzed by the inducible nitric oxide synthase (iNOS) has been implicated as a major defense against Leishmania infection. The modulation of this microbicidal mechanism by different species of Leishmania has been well studied in M phi. Although DC are permissive for infection with Leishmania both in vivo and in vitro, the effect of this parasite in the expression of iNOS and NO production in these cells has not been established. To address this issue, we analyzed the regulation of iNOS by Leishmania mexicana amastigotes in murine bone marrow-derived dendritic cells (BMDC) stimulated with LPS and IFN-gamma. We show that the infection of BMDC with amastigotes down regulated NO production and diminished iNOS protein levels in cells stimulated with LPS alone or in combination with IFN-gamma. The reduction in iNOS protein levels and NO production did not correlate with a decrease in iNOS mRNA expression, suggesting that the parasite affects post-transcriptional events of NO synthesis. Although amastigotes were able to reduce NO production in BMDC, the interference with this cytotoxic mechanism was not sufficient to permit the survival of L. mexicana. At 48 h post-infection, BMDC stimulated with LPS+IFN-gamma were able to eliminate the parasites. These results are the first to identify the regulation of iNOS by L. mexicana amastigotes in DC.
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15
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Karst SM. Pathogenesis of noroviruses, emerging RNA viruses. Viruses 2010; 2:748-781. [PMID: 21994656 PMCID: PMC3185648 DOI: 10.3390/v2030748] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 03/15/2010] [Accepted: 03/15/2010] [Indexed: 12/13/2022] Open
Abstract
Human noroviruses in the family Caliciviridae are a major cause of epidemic gastroenteritis. They are responsible for at least 95% of viral outbreaks and over 50% of all outbreaks worldwide. Transmission of these highly infectious plus-stranded RNA viruses occurs primarily through contaminated food or water, but also through person-to-person contact and exposure to fomites. Norovirus infections are typically acute and self-limited. However, disease can be much more severe and prolonged in infants, elderly, and immunocompromised individuals. Norovirus outbreaks frequently occur in semi-closed communities such as nursing homes, military settings, schools, hospitals, cruise ships, and disaster relief situations. Noroviruses are classified as Category B biodefense agents because they are highly contagious, extremely stable in the environment, resistant to common disinfectants, and associated with debilitating illness. The number of reported norovirus outbreaks has risen sharply since 2002 suggesting the emergence of more infectious strains. There has also been increased recognition that noroviruses are important causes of childhood hospitalization. Moreover, noroviruses have recently been associated with multiple clinical outcomes other than gastroenteritis. It is unclear whether these new observations are due to improved norovirus diagnostics or to the emergence of more virulent norovirus strains. Regardless, it is clear that human noroviruses cause considerable morbidity worldwide, have significant economic impact, and are clinically important emerging pathogens. Despite the impact of human norovirus-induced disease and the potential for emergence of highly virulent strains, the pathogenic features of infection are not well understood due to the lack of a cell culture system and previous lack of animal models. This review summarizes the current understanding of norovirus pathogenesis from the histological to the molecular level, including contributions from new model systems.
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Affiliation(s)
- Stephanie M. Karst
- Center for Molecular and Tumor Virology, Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130-3932, USA; E-Mail: ; Tel.: +1-318-675-8122; Fax: +1-318-675-5764
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16
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Differential response of respiratory dendritic cell subsets to influenza virus infection. J Virol 2008; 82:4908-19. [PMID: 18353940 DOI: 10.1128/jvi.02367-07] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dendritic cells (DC) are believed to play an important role in the initiation of innate and adaptive immune responses to infection, including respiratory tract infections, where respiratory DC (RDC) perform this role. In this report, we examined the susceptibilities of isolated murine RDC to influenza virus infection in vitro and the effect of the multiplicity of infection (MOI) on costimulatory ligand upregulation and inflammatory cytokine/chemokine production after infection. We found that the efficiency of influenza virus infection of RDC increased with increasing MOIs. Furthermore, distinct subpopulations of RDC differed in their susceptibilities to influenza virus infection and in the magnitude/tempo of costimulatory ligand expression. Additional characterization of the CD11c-positive (CD11c(+)) RDC revealed that the identifiable subsets of RDC differed in susceptibility to infection, with CD11c(+) CD103(+) DC exhibiting the greatest susceptibility, CD11c(+) CD11b(hi) DC exhibiting intermediate susceptibility, and CD11c(+) B220(+) plasmacytoid DC (pDC) exhibiting the least susceptibility to infection. A companion analysis of the in vivo susceptibilities of these RDC subsets to influenza virus revealed a corresponding infection pattern. The three RDC subsets displayed different patterns of cytokine/chemokine production in response to influenza virus infection in vitro: pDC were the predominant producers of most cytokines examined, while CD103(+) DC and CD11b(hi) DC produced elevated levels of the murine chemokine CXCL1 (KC), interleukin 12p40, and RANTES in response to influenza virus infection. Our results indicate that RDC are targets of influenza virus infection and that distinct RDC subsets differ in their susceptibilities and responses to infection.
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17
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Normal proportion and expression of maturation markers in migratory dendritic cells in the absence of germs or Toll-like receptor signaling. Immunol Cell Biol 2007; 86:200-5. [PMID: 18026177 DOI: 10.1038/sj.icb.7100125] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dendritic cells (DCs) play major roles in immunosurveillance. In peripheral tissues, 'immature' DCs are dedicated to capturing antigens. Detection of pathogens through Toll-like receptors (TLRs) triggers DC migration to the lymph nodes (LNs), where they acquire a 'mature' phenotype specialized at presenting antigens. However, DCs migrate from tissues and mature even in the absence of overt infections. This has been attributed to detection of commensal flora in the skin, the gut or other peripheral tissues in the steady state. To test this assumption, we have analyzed the DCs contained in the lymphoid organs of germ-free mice and of mice lacking the TLR adapter molecules, MyD88 and TRIF. We show that the proportion and expression of maturation markers in DC immigrants in the LNs of these mice are similar to those in normal mice. These results suggest that DC migration from tissues, followed by their phenotypic maturation, is regulated in the steady state by an inherent program of DC differentiation or by the release of low levels of inflammatory signals from normal tissues.
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18
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Belz GT, Bedoui S, Kupresanin F, Carbone FR, Heath WR. Minimal activation of memory CD8+ T cell by tissue-derived dendritic cells favors the stimulation of naive CD8+ T cells. Nat Immunol 2007; 8:1060-6. [PMID: 17767161 DOI: 10.1038/ni1505] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2007] [Accepted: 07/24/2007] [Indexed: 01/02/2023]
Abstract
Of the many dendritic cell (DC) subsets, DCs expressing the monomorphic coreceptor CD8 alpha-chain (CD8alpha) are localized permanently in lymphoid organs, whereas 'tissue-derived DCs' remain in nonlymphoid tissues until they 'capture' antigen and then move to local lymph nodes. Here we show that after lung infection, both naive and memory CD8+ 'killer' T cells responded to influenza virus antigens presented by lymph node-resident CD8alpha+ DCs, but only naive cells responded to antigens presented by lung-derived DCs. This difference provides a mechanism for priming naive T cell responses in conditions in which robust memory predominates. Our findings have implications for immunity to pathogens that can mutate their T cell epitopes, such as influenza virus and human immunodeficiency virus, and challenge the long-held view that memory T cells have less-stringent requirements for activation than naive T cells have.
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Affiliation(s)
- Gabrielle T Belz
- Immunology Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3050, Australia.
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19
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Schleicher U, Liese J, Knippertz I, Kurzmann C, Hesse A, Heit A, Fischer JAA, Weiss S, Kalinke U, Kunz S, Bogdan C. NK cell activation in visceral leishmaniasis requires TLR9, myeloid DCs, and IL-12, but is independent of plasmacytoid DCs. ACTA ACUST UNITED AC 2007; 204:893-906. [PMID: 17389237 PMCID: PMC2118560 DOI: 10.1084/jem.20061293] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Natural killer (NK) cells are sentinel components of the innate response to pathogens, but the cell types, pathogen recognition receptors, and cytokines required for their activation in vivo are poorly defined. Here, we investigated the role of plasmacytoid dendritic cells (pDCs), myeloid DCs (mDCs), Toll-like receptors (TLRs), and of NK cell stimulatory cytokines for the induction of an NK cell response to the protozoan parasite Leishmania infantum. In vitro, pDCs did not endocytose Leishmania promastigotes but nevertheless released interferon (IFN)-alpha/beta and interleukin (IL)-12 in a TLR9-dependent manner. mDCs rapidly internalized Leishmania and, in the presence of TLR9, produced IL-12, but not IFN-alpha/beta. Depletion of pDCs did not impair the activation of NK cells in L. infantum-infected mice. In contrast, L. infantum-induced NK cell cytotoxicity and IFN-gamma production were abolished in mDC-depleted mice. The same phenotype was observed in TLR9(-/-) mice, which lacked IL-12 expression by mDCs, and in IL-12(-/-) mice, whereas IFN-alpha/beta receptor(-/-) mice showed only a minor reduction of NK cell IFN-gamma expression. This study provides the first direct evidence that mDCs are essential for eliciting NK cell cytotoxicity and IFN-gamma release in vivo and demonstrates that TLR9, mDCs, and IL-12 are functionally linked to the activation of NK cells in visceral leishmaniasis.
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MESH Headings
- Animals
- CD11c Antigen/metabolism
- Cell Differentiation
- DNA, Protozoan/genetics
- Dendritic Cells/cytology
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Female
- Interferon-alpha/biosynthesis
- Interferon-beta/biosynthesis
- Interleukin-12/deficiency
- Interleukin-12/genetics
- Interleukin-12/immunology
- Killer Cells, Natural/cytology
- Killer Cells, Natural/immunology
- Leishmania donovani/genetics
- Leishmaniasis, Visceral/immunology
- Leishmaniasis, Visceral/metabolism
- Leishmaniasis, Visceral/parasitology
- Leishmaniasis, Visceral/pathology
- Lymphocyte Activation/immunology
- Mice
- Mice, Knockout
- Myeloid Cells/cytology
- Myeloid Cells/immunology
- Phenotype
- Receptor, Interferon alpha-beta/deficiency
- Receptor, Interferon alpha-beta/genetics
- Receptor, Interferon alpha-beta/metabolism
- Toll-Like Receptor 9/immunology
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Affiliation(s)
- Ulrike Schleicher
- Institute of Medical Microbiology and Hygiene, University of Freiburg, D-79104 Freiburg, Germany
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20
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Abstract
Leishmania are digenetic protozoan parasites that are inoculated into the skin by vector sand flies, are taken up by macrophages, and produce a spectrum of chronic diseases in their natural reservoir and susceptible human hosts. During the early establishment of infection in the skin and lymphoid organs, Leishmania produce multiple effects on macrophage and dendritic cell functions that inhibit their innate anti-microbial defenses and impair their capacity to initiate T-helper 1 cell immunity. In addition, the skin is a site preconditioned for early parasite survival by virtue of a high frequency of steady-state, natural CD25+Foxp3+ regulatory T cells (Tregs) that function to suppress the generation of unneeded immune responses to infectious and non-infectious antigens to which the skin is regularly exposed. In murine models of infection, antigen-induced CD25+/-Foxp3-interleukin (IL)-10+ Treg cells act during the effector phase of the immune response to control immunopathology and may also delay or prevent healing. Finally, following resolution of infection in healed mice, CD25+Foxp3+ Tregs function in an IL-10-dependent manner to prevent sterile cure and establish a long-term state of functional immune privilege in the skin.
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Affiliation(s)
- Nathan Peters
- Laboratory of Parasitic Diseases, NIAID, Bethesda, MD 20892-0425, USA
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21
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Salem ML, Gillanders WE, Kadima AN, El-Naggar S, Rubinstein MP, Demcheva M, Vournakis JN, Cole DJ. Review: novel nonviral delivery approaches for interleukin-12 protein and gene systems: curbing toxicity and enhancing adjuvant activity. J Interferon Cytokine Res 2006; 26:593-608. [PMID: 16978064 DOI: 10.1089/jir.2006.26.593] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
It has become increasingly apparent that the ability to generate an optimal host immune response requires effective cross talk between the innate and adaptive components of the immune system. Pro-inflammatory cytokines, in particular those that can induce a danger signal, often called signal 3, are crucial in this role of initiating and augmenting the presentation of exogenous antigen to T cells by dendritic cells. Interleukin-12 (IL-12) in particular has been defined as a "signal 3" cytokine required for the antigen cross priming. Given this unique interactive function, a significant amount of work has been performed to define possible therapeutic applications for IL-12. Systemic IL-12 administration can clearly act as a potent adjuvant for postvaccination T cell responses in a variety of diseases. As an example, in the cancer setting, systemic IL-12 is capable of suppressing tumor growth, metastasis, and angiogenesis in vivo. IL-12, however, has been associated with significant dose- and schedule-dependent toxicity in early clinical trials, results that have proven to be a major obstacle to its clinical application. Recent research has focused on decreasing the toxicity of IL-12 using different delivery approaches, including virus-based and gene-modified cell-based delivery. Although effective, these approaches also have limitations, including the generation of neutralizing antibodies, in addition to lacking the simplicity and versatility required for universal clinical application. Thus, there is a significant interest in the development of alternative delivery approaches for IL-12 administration that can overcome these issues. Several nonviral delivery approaches for IL-12 protein or gene expression vectors are being defined, including alum, liposomes, and polymer-based delivery. These developing approaches have shown promising adjuvant effects with significantly lessened systemic toxicity. This article discusses the potential capabilities of these nonvirus-based IL-12 delivery systems in different disease settings, including allergy, infection, and cancer.
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Affiliation(s)
- Mohamed Labib Salem
- Department of Surgery, Section of Surgical Oncology, Medical University of South Carolina, Charleston, SC 29425, USA.
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22
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Lahoud MH, Proietto AI, Gartlan KH, Kitsoulis S, Curtis J, Wettenhall J, Sofi M, Daunt C, O'keeffe M, Caminschi I, Satterley K, Rizzitelli A, Schnorrer P, Hinohara A, Yamaguchi Y, Wu L, Smyth G, Handman E, Shortman K, Wright MD. Signal regulatory protein molecules are differentially expressed by CD8- dendritic cells. THE JOURNAL OF IMMUNOLOGY 2006; 177:372-82. [PMID: 16785533 DOI: 10.4049/jimmunol.177.1.372] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A normalized subtracted gene expression library was generated from freshly isolated mouse dendritic cells (DC) of all subtypes, then used to construct cDNA microarrays. The gene expression profiles of the three splenic conventional DC (cDC) subsets were compared by microarray hybridization and two genes encoding signal regulatory protein beta (Sirpbeta1 and Sirpbeta4) molecules were identified as differentially expressed in CD8(-) cDC. Genomic sequence analysis revealed a third Sirpbeta member localized in the same gene cluster. These Sirpbeta genes encode cell surface molecules containing extracellular Ig domains and short intracytoplasmic domains that have a charged amino acid in the transmembrane region which can potentially interact with ITAM-bearing molecules to mediate signaling. Indeed, we demonstrated interactions between Sirpbeta1 and beta2 with the ITAM-bearing signaling molecule Dap12. Real-time PCR analysis showed that all three Sirpbeta genes were expressed by CD8(-) cDC, but not by CD8(+) cDC or plasmacytoid pre-DC. The related Sirpalpha gene showed a similar expression profile on cDC subtypes but was also expressed by plasmacytoid pre-DC. The differential expression of Sirpalpha and Sirpbeta1 molecules on DC was confirmed by staining with mAbs, including a new mAb recognizing Sirpbeta1. Cross-linking of Sirpbeta1 on DC resulted in a reduction in phagocytosis of Leishmania major parasites, but did not affect phagocytosis of latex beads, perhaps indicating that the regulation of phagocytosis by Sirpbeta1 is a ligand-dependent interaction. Thus, we postulate that the differential expression of these molecules may confer the ability to regulate the phagocytosis of particular ligands to CD8(-) cDC.
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Affiliation(s)
- Mireille H Lahoud
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia.
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23
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Alexandre-Pires G, Pais D, Correia M, Pina JAE. Leishmaniosis--a report about the microvascular and cellular architecture of the infected spleen in Canis familiaris. Microsc Res Tech 2006; 69:227-35. [PMID: 16586484 DOI: 10.1002/jemt.20267] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Leishmaniosis is an anthropozoonosis caused by an intracellular protozoan parasite that causes a wide spectrum of diseases in humans and dogs worldwide. In the Mediterranean basin, Portugal, Central and South America, and in the Middle East, visceral leishmaniosis is caused by Leishmania infantum. In these areas, dogs are believed to be the natural reservoirs of this parasite. In the case of visceral leishmaniosis, the spleen is one of the several hematopoietic and immunocompetent organs involved. Since this viscera is a blood filter, the authors investigated the expression of the morphological and microvascular environment and modifications of the spleen cell population related to immunological responses to this parasitic condition. The tools used to perform this study were scanning electronic microscopy of intact tissue and corrosion casts, transmission electronic microscopy, histology and immunohistochemistry. The results reveal three important modifications concerning the spleen's microvascular architecture when compared with its normal pattern, independently of the serological titer obtained with indirect immunofluorescence. (1) A marked scarcity of the sinusoidal system sheet that surrounds the central artery/arteriole of the white pulp; (2) A huge development of pulp venules and veins; (3) The presence of a surprising development of reticular fibers. The authors postulate that independent of the virulence of the parasite involved and the type of immunity prevalent in a particular host, the spleen develops blood dynamic conditions that permit reduction in the speed of blood flow so that cells involved in immunological processes can proliferate and differentiate, and also contributes to trapping lymphocytes within the area through the differentiation of characteristics that resemble those of HEV endothelial cells.
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Affiliation(s)
- G Alexandre-Pires
- Faculty of Veterinary Medicine (Anatomy), Rua Prof. Cid dos Santos, 1300-477 Lisbon, Portugal.
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24
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Prickett S, Gray PM, Colpitts SL, Scott P, Kaye PM, Smith DF. In vivo recognition of ovalbumin expressed by transgenic Leishmania is determined by its subcellular localization. THE JOURNAL OF IMMUNOLOGY 2006; 176:4826-33. [PMID: 16585577 PMCID: PMC2695601 DOI: 10.4049/jimmunol.176.8.4826] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The importance of the site of Ag localization within microbial pathogens for the effective generation of CD8+ T cells has been studied extensively, generally supporting the view that Ag secretion within infected target cells is required for optimal MHC class I-restricted Ag presentation. In contrast, relatively little is known about the importance of pathogen Ag localization for the activation of MHC class II-restricted CD4+ T cells, despite their clear importance for host protection. We have used the N-terminal targeting sequence of Leishmania major hydrophilic acylated surface protein B to generate stable transgenic lines expressing physiologically relevant levels of full-length OVA on the surface of metacyclic promastigotes and amastigotes. In addition, we have mutated the hydrophilic acylated surface protein B N-terminal acylation sequence to generate control transgenic lines in which OVA expression is restricted to the parasite cytosol. In vitro, splenic dendritic cells are able to present membrane-localized, but not cytosolic, OVA to OVA-specific DO.11 T cells. Strikingly and unexpectedly, surface localization of OVA is also a strict requirement for recognition by OVA-specific T cells (DO.11 and OT-II) and for the development of OVA-specific Ab responses in vivo. However, recognition of cytosolic OVA could be observed with increasing doses of infection. These data suggest that, even under in vivo conditions, where varied pathways of Ag processing are likely to operate, the site of Leishmania Ag localization is an important determinant of immunogenicity and hence an important factor when considering the likely candidacy of vaccine Ags for inducing CD4+ T cell-dependent immunity.
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Affiliation(s)
- Sara Prickett
- Wellcome Trust Laboratories for Molecular Parasitology, Centre for Molecular Microbiology and Infection, Imperial College, London, United Kingdom
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Peter M. Gray
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Sara L. Colpitts
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Phillip Scott
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Paul M. Kaye
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Deborah F. Smith
- Wellcome Trust Laboratories for Molecular Parasitology, Centre for Molecular Microbiology and Infection, Imperial College, London, United Kingdom
- Address correspondence and reprint requests to Dr. Deborah F. Smith, Immunology and Infection Unit, Department of Biology/Hull York Medical School, University of York, Heslington, York YO10 5YW, U.K. E-mail address:
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25
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Bogdan C, Schleicher U. Production of interferon-gamma by myeloid cells--fact or fancy? Trends Immunol 2006; 27:282-90. [PMID: 16698319 DOI: 10.1016/j.it.2006.04.004] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Revised: 03/17/2006] [Accepted: 04/20/2006] [Indexed: 02/08/2023]
Abstract
Myeloid cells are usually viewed as targets rather than producers of interferon (IFN)-gamma. However, since 1993 several studies have suggested that macrophages and dendritic cells can also secrete IFN-gamma in response to various stimuli, which led to the idea of autocrine myeloid-cell activation in innate immunity. Here, we review this concept in the light of recent findings that illustrate the necessity of specific cell markers, cell purity, sensitive single-cell cytokine detection methods, and of further insights into the developmental origin of myeloid and lymphoid cell lineages. We also discuss the possible function of intracellular IFN-gamma in macrophages and the evidence for a protective role of myeloid IFN-gamma in vivo.
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Affiliation(s)
- Christian Bogdan
- Department of Microbiology and Hygiene, Institute of Medical Microbiology and Hygiene, University of Freiburg, Hermann-Herder-Strasse 11, D-79104 Freiburg, Germany.
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Körner U, Fuss V, Steigerwald J, Moll H. Biogenesis of Leishmania major-harboring vacuoles in murine dendritic cells. Infect Immun 2006; 74:1305-12. [PMID: 16428780 PMCID: PMC1360340 DOI: 10.1128/iai.74.2.1305-1312.2006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In mammalian hosts, Leishmania sp. parasites are obligatory intracellular organisms that invade macrophages and dendritic cells (DC), where they reside in endocytic organelles termed parasitophorous vacuoles (PV). Most of the present knowledge of the characteristics of PV harboring Leishmania sp. is derived from studies with infected macrophages. Since DC play a key role in host resistance to leishmaniasis, there is a need to understand the properties and biogenesis of PV in Leishmania sp.-infected DC. Therefore, we determined the acquisition of endosomal and lysosomal molecules by Leishmania major-containing compartments in DC at different maturation stages, using fluorescence labeling and confocal microscopy. The results show that newly formed phagosomes in DC rapidly develop into late endosomal compartments. However, the small GTPase Rab7, which regulates late fusion processes, was found only in PV of mature bone marrow-derived DC (BMDC); it was absent in immature BMDC, suggesting an arrest of their PV biogenesis at the stage of late endosomes. Indeed, fusion assays with endocytic tracers demonstrated that the fusion activity of L. major-harboring PV toward lysosomes is higher in mature BMDC than in immature BMDC. The inhibition of PV-lysosome fusion in DC is dependent upon the viability and life cycle stage of the parasite, because live promastigotes blocked the fusion almost completely, whereas killed organisms and amastigotes induced a considerable level of fusion activity. The differences in the fusion competences of immature and mature DC may be relevant for their distinct functional activities in the uptake, transport, and presentation of parasite antigens.
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Affiliation(s)
- Ulrich Körner
- Institut für Molekulare Infektionsbiologie, Universität Würzburg, Röntgenring 11, D-97070 Würzburg, Germany
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Breton M, Tremblay MJ, Ouellette M, Papadopoulou B. Live nonpathogenic parasitic vector as a candidate vaccine against visceral leishmaniasis. Infect Immun 2005; 73:6372-82. [PMID: 16177308 PMCID: PMC1230936 DOI: 10.1128/iai.73.10.6372-6382.2005] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
To date, there are no proven vaccines against any form of leishmaniasis. The development of live attenuated vectors shows promise in the field of Leishmania vaccination because these organisms mimic more effectively the course of real infections and can elicit potent activation of the immune system. In the present study, we investigated the potential of a parasitic protozoan that is nonpathogenic to humans, Leishmania tarentolae, as a live candidate vaccine that efficiently targets dendritic cells and lymphoid organs, thus enhancing antigen presentation and consequently influencing the magnitude and quality of T-cell immune responses. We demonstrated that L. tarentolae activates the dendritic cell maturation process and induces T-cell proliferation and the production of gamma interferon, thus skewing CD4(+) T cells toward a Th1 cell phenotype. More importantly, we found that a single intraperitoneal injection of L. tarentolae could elicit a protective immune response against infectious challenge with Leishmania donovani in susceptible BALB/c mice. These results suggest that the use of L. tarentolae as a live vaccine vector may represent a promising approach for improving the effectiveness and safety of candidate live vaccines against Leishmania infections and possibly other intracellular pathogens for which T-cell mediated responses are critical for the development of protective immunity.
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Affiliation(s)
- Marie Breton
- Infectious Diseases Research Center, CHUL Research Center of Laval University, Quebec, Canada
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28
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Caparrós E, Serrano D, Puig-Kröger A, Riol L, Lasala F, Martinez I, Vidal-Vanaclocha F, Delgado R, Rodríguez-Fernández JL, Rivas L, Corbí AL, Colmenares M. Role of the C-type lectins DC-SIGN and L-SIGN in Leishmania interaction with host phagocytes. Immunobiology 2005; 210:185-93. [PMID: 16164025 PMCID: PMC7114652 DOI: 10.1016/j.imbio.2005.05.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Leishmaniasis is a parasitic disease that courses with cutaneous or visceral clinical manifestations. The amastigote stage of the parasite infects phagocytes and modulates the effector function of the host cells. Our group has described that the interaction between Leishmania and immature monocyte-derived dendritic cells (DCs) takes place through dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN), a C-type lectin that specifically recognizes fungal, viral and bacterial pathogens. The DC-SIGN-mediated recognition of Leishmania amastigotes does not induce DC maturation, and the DC-SIGN ligand/s on Leishmania parasites is/are still unknown. We have also found that the DC-SIGN-related molecule L-SIGN, specifically expressed in lymph node and liver sinusoidal endothelial cells, acts as a receptor for L. infantum, the parasite responsible for visceral leishmaniasis, but does not recognize L. pifanoi, which causes the cutaneous form of the disease. Therefore, DC-SIGN and L-SIGN differ in their ability to interact with Leishmania species responsible for either visceral or cutaneous leishmaniasis. A deeper knowledge of the parasite-C-type lectin interaction may be helpful for the design of new DC-based therapeutic vaccines against Leishmania infections.
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Affiliation(s)
- Esther Caparrós
- Centro de Investigaciones Biológicas (CSIC), Calle Ramiro de Maeztu 9, 28040 Madrid, Spain
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Liu J, Cao S, Kim S, Chung EY, Homma Y, Guan X, Jimenez V, Ma X. Interleukin-12: an update on its immunological activities, signaling and regulation of gene expression. CURRENT IMMUNOLOGY REVIEWS 2005; 1:119-137. [PMID: 21037949 DOI: 10.2174/1573395054065115] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Interleukin-12 (IL-12) is a heterodimeric cytokine composed of the p35 and p40 subunits. It is produced by antigen-presenting cells and plays a critical role in host defense against intracellular microbial infection and control of malignancy via its ability to stimulate both innate and adaptive immune effector cells. The potency of IL-12 renders itself to stringent regulation of the timing, locality and magnitude of its production during an immune response. Subversion of the delicate control and balance frequently leads to immunologic disorders. In this article, we provide an update, since our last review of the subject four years ago, on recent advances in: (1) uncovering of novel activities of IL-12 and related molecules in various immunological settings and models; and (2) dissection of the physiological pathways involved in the modulation of IL-12 production by pathogens and immune regulators. The increased understanding of IL-12 immunobiology and expression will likely benefit the development of therapeutic modalities to correct immune dysfunctions.
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Antoine JC, Prina E, Courret N, Lang T. Leishmania spp.: on the interactions they establish with antigen-presenting cells of their mammalian hosts. ADVANCES IN PARASITOLOGY 2005; 58:1-68. [PMID: 15603761 DOI: 10.1016/s0065-308x(04)58001-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Identification of macrophages as host cells for the mammalian stage of Leishmania spp. traces back to about 40 years ago, but many questions concerning the ways these parasites establish themselves in these cells, which are endowed with potent innate microbicidal mechanisms, are still unanswered. It is known that microbicidal activities of macrophages can be enhanced or induced by effector T lymphocytes following the presentation of antigens via MHC class I or class II molecules expressed at the macrophage plasma membrane. However, Leishmania spp. have evolved mechanisms to evade or to interfere with antigen presentation processes, allowing parasites to partially resist these T cell-mediated immune responses. Recently, the presence of Leishmania amastigotes within dendritic cells has been reported suggesting that they could also be host cells for these parasites. Dendritic cells have been described as the only cells able to induce the activation of naive T lymphocytes. However, certain Leishmania species infect dendritic cells without inducing their maturation and impair the migration of these cells, which could delay the onset of the adaptive immune responses as both processes are required for naive T cell activation. This review examines how Leishmania spp. interact with these two cell types, macrophages and dendritic cells, and describes some of the strategies used by Leishmania spp. to survive in these inducible or constitutive antigen-presenting cells.
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Affiliation(s)
- Jean-Claude Antoine
- Unité d'Immunophysiologie et Parasitisme Intracellulaire, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris cedex 15, France.
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Abstract
Leishmania are digenetic protozoa which inhabit two highly specific hosts, the sandfly where they grow as motile, flagellated promastigotes in the gut, and the mammalian macrophage where they grow intracellularly as non-flagellated amastigotes. Leishmaniasis is the outcome of an evolutionary 'arms race' between the host's immune system and the parasite's evasion mechanisms which ensure survival and transmission in the population. The spectrum of disease manifestations and severity reflects the interaction between the genome of the host and that of the parasite, and the pathology is caused by a combination of host and parasite molecules. This chapter examines the genetic basis of host susceptibility to disease in humans and animal models. It describes the genetic tools used to map and identify susceptibility genes, and the lessons learned from murine and human cutaneous leishmaniasis.
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Affiliation(s)
- Emanuela Handman
- The Walter and Eliza Hall Institute of Medical Research, Post Office, Royal Melbourne Hospital, Victoria 3050, Australia
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Wilson NS, Villadangos JA. Regulation of Antigen Presentation and Cross-Presentation in the Dendritic Cell Network: Facts, Hypothesis, and Immunological Implications. Adv Immunol 2005; 86:241-305. [PMID: 15705424 DOI: 10.1016/s0065-2776(04)86007-3] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Dendritic cells (DCs) are central to the maintenance of immunological tolerance and the initiation and control of immunity. The antigen-presenting properties of DCs enable them to present a sample of self and foreign proteins, contained within an organism at any given time, to the T-cell repertoire. DCs achieve this communication with T cells by displaying antigenic peptides bound to MHC I and MHC II molecules. Here we review the studies carried out over the past 15 years to characterize these antigen presentation mechanisms, emphasizing their significance in relation to DC function in vivo. The life cycles of different DC populations found in vivo are described. Furthermore, we provide a critical assessment of the studies that examine the mechanisms controlling DC MHC class II antigen presentation, which have often reached contradictory conclusions. Finally, we review findings pertaining to the biological mechanisms that enable DCs to present exogenous antigens on their MHC class I molecules, a process known as cross-presentation. Throughout, we highlight what we consider to be major knowledge gaps in the field and speculate on possible directions for future research.
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Affiliation(s)
- Nicholas S Wilson
- Immunology Division and The Cooperative Research Center for Vaccine Technology, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia
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Abstract
Dendritic cells (DCs) are key elements of the immune system, which function as sentinel in the periphery and alert T lymphocytes about the type of invading antigen and address their polarisation, in order to mount an efficacious immune response. Leishmania spp. are parasitic protozoa which may cause severe disease in humans and domestic animals. In this work, the main studies concerning the role of DCs in Leishmania infection are reviewed, in both the murine and human models. In particular, the importance of the genetic status of the hosts and of the different Leishmania species in modulating DC-mediated immune response is examined. In addition, different approaches of DC-based vaccination against experimental leishmaniasis, which could have important future applications, are summarised.
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Affiliation(s)
- Olga Brandonisio
- Department of Internal Medicine, Immunology and Infectious Diseases, University of Bari Medical School, Bari, Italy.
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Lemos MP, Esquivel F, Scott P, Laufer TM. MHC class II expression restricted to CD8alpha+ and CD11b+ dendritic cells is sufficient for control of Leishmania major. ACTA ACUST UNITED AC 2004; 199:725-30. [PMID: 14993255 PMCID: PMC2213304 DOI: 10.1084/jem.20030795] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Control of the intracellular protozoan, Leishmania major, requires major histocompatibility complex class II (MHC II)–dependent antigen presentation and CD4+ T cell T helper cell 1 (Th1) differentiation. MHC II–positive macrophages are a primary target of infection and a crucial effector cell controlling parasite growth, yet their function as antigen-presenting cells remains controversial. Similarly, infected Langerhans cells (LCs) can prime interferon (IFN)γ–producing Th1 CD4+ T cells, but whether they are required for Th1 responses is unknown. We explored the antigen-presenting cell requirement during primary L. major infection using a mouse model in which MHC II, I-Aβb, expression is restricted to CD11b+ and CD8α+ dendritic cells (DCs). Importantly, B cells, macrophages, and LCs are all MHC II–negative in these mice. We demonstrate that antigen presentation by these DC subsets is sufficient to control a subcutaneous L. major infection. CD4+ T cells undergo complete Th1 differentiation with parasite-specific secretion of IFNγ. Macrophages produce inducible nitric oxide synthase, accumulate at infected sites, and control parasite numbers in the absence of MHC II expression. Therefore, CD11b+ and CD8α+ DCs are not only key initiators of the primary response but also provide all the necessary cognate interactions for CD4+ T cell Th1 effectors to control this protozoan infection.
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Affiliation(s)
- Maria P Lemos
- Department of Medicine, University of Pennsylvania, Philadelphia 19104, USA
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Baldwin T, Henri S, Curtis J, O'Keeffe M, Vremec D, Shortman K, Handman E. Dendritic cell populations in Leishmania major-infected skin and draining lymph nodes. Infect Immun 2004; 72:1991-2001. [PMID: 15039319 PMCID: PMC375196 DOI: 10.1128/iai.72.4.1991-2001.2004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using a metacyclic promastigote ear infection model of cutaneous leishmaniasis, we examined the phenotype, parasite load, and cytokine production of dendritic cells in the skin and draining lymph nodes of resistant C57BL/6J and susceptible BALB/c mice. Five dendritic cell populations were isolated from the skin and lymph nodes, and the main difference between the groups of mice was an increased number of plasmacytoid dendritic cells in the lymph nodes of the susceptible mice. Although similar cell types were present in the skin emigrants of both strains, there was a 10-fold larger number of cells in BALB/c mouse skin early in infection than in C57BL/6J mouse skin. None of the dendritic cells in the lymph nodes harbored parasites until 3 weeks after infection, with the Langerhans cells having the largest load and the plasmacytoid dendritic cells having the smallest load but the longest lasting infection. Although parasites could be detected in the lymph nodes a few hours after infection, none of the skin emigrants harbored parasites, indicating that they are not the vehicle that ferries the parasites from the skin to the lymph nodes. The presence of larger numbers of plasmacytoid cells in infected BALB/c mice, the more protracted infection of these cells, and their production of alpha interferon point to a complex and important role for the plasmacytoid cells in leishmaniasis.
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Affiliation(s)
- Tracey Baldwin
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
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36
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Prina E, Abdi SZ, Lebastard M, Perret E, Winter N, Antoine JC. Dendritic cells as host cells for the promastigote and amastigote stages of Leishmania amazonensis: the role of opsonins in parasite uptake and dendritic cell maturation. J Cell Sci 2003; 117:315-25. [PMID: 14657281 DOI: 10.1242/jcs.00860] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In their mammalian hosts, Leishmania are obligate intracellular parasites that mainly reside in macrophages. They are also phagocytosed by dendritic cells (DCs), which play decisive roles in the induction and shaping of T cell-dependent immune responses. Little is known about the role of DCs in the Leishmania life cycle. Here, we examined the ability of mouse bone marrow-derived DCs to serve as hosts for L. amazonensis. Both infective stages of Leishmania (metacyclic promastigotes and amastigotes) could be phagocytosed by DCs, regardless of whether they had previously been experimentally opsonized with either the complement C3 component or specific antibodies. Parasites could survive and even multiply in these cells for at least 72 hours, within parasitophorous vacuoles displaying phagolysosomal characteristics and MHC class II and H-2M molecules. We then studied the degree of maturation reached by infected DCs according to the parasite stage internalised and the type of opsonin used. The cell surface expression of CD24, CD40, CD54, CD80, CD86, OX40L and MHC class II molecules was barely altered following infection with unopsonized promastigotes or amastigotes from nude mice or with C3-coated promastigotes. Even 69 hours post-phagocytosis, a large proportion of infected DCs remained phenotypically immature. In contrast, internalisation of antibody-opsonized promastigotes or amastigotes induced DCs to mature rapidly, as shown by the over-expression of costimulatory, adhesion and MHC class II molecules. Thus, in the absence of specific antibodies (e.g. shortly after infecting naive mammals), infected DCs may remain immature or semi-mature, meaning that they are unable to elicit an efficient anti-Leishmania T cell response. Absence of DC maturation or delayed/incomplete DC maturation could thus be beneficial for the parasites, allowing their establishment and amplification before the onset of immune responses.
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Affiliation(s)
- Eric Prina
- Unité d'Immunophysiologie et Parasitisme Intracellulaire, Institut Pasteur, Paris, France.
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Abstract
Parasites represent a diverse group of pathogens that often trigger highly polarized immune responses that become tightly regulated during chronic infection. Recent studies have implicated the parasite-dendritic-cell interaction as a key determinant of the host response to these eukaryotic invaders. Dendritic cells appear to be pivotal in the initiation of cellular immunity against parasites as well as in directing Th1/Th2 effector choice. Moreover, there is increasing evidence that parasites regulate dendritic-cell function for the purposes of evading host immunity. This regulation also benefits parasites by protecting their host niche from the potentially lethal consequences of an uncontrolled inflammatory response.
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Affiliation(s)
- Alan Sher
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892-8003, USA.
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Hogg KG, Kumkate S, Anderson S, Mountford AP. Interleukin-12 p40 secretion by cutaneous CD11c+ and F4/80+ cells is a major feature of the innate immune response in mice that develop Th1-mediated protective immunity to Schistosoma mansoni. Infect Immun 2003; 71:3563-71. [PMID: 12761141 PMCID: PMC155763 DOI: 10.1128/iai.71.6.3563-3571.2003] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Radiation-attenuated (RA) schistosome larvae are potent stimulators of innate immune responses at the skin site of exposure (pinna) that are likely to be important factors in the development of Th1-mediated protective immunity. In addition to causing an influx of neutrophils, macrophages, and dendritic cells (DCs) into the dermis, RA larvae induced a cascade of chemokine and cytokine secretion following in vitro culture of pinna biopsy samples. While macrophage inflammatory protein 1alpha and interleukin-1beta (IL-1beta) were produced transiently within the first few days, the Th1-promoting cytokines IL-12 and IL-18 were secreted at high levels until at least day 14. Assay of C3H/HeJ mice confirmed that IL-12 secretion was not due to lipopolysaccharide contaminants binding Toll-like receptor 4. Significantly, IL-12 p40 secretion was sustained in pinnae from vaccinated mice but not in those from nonprotected infected mice. In contrast, IL-10 was produced from both vaccinated and infected mice. This cytokine regulates IL-12-associated dermal inflammation, since in vaccinated IL-10(-/-) mice, pinna thickness was greatly increased concurrent with elevated levels of IL-12 p40. A significant number of IL-12 p40(+) cells were detected as emigrants from in vitro-cultured pinnae, and most were within a population of rare large granular cells that were Ia(+), consistent with their being antigen-presenting cells. Labeling of IL-12(+) cells for CD11c, CD205, CD8alpha, CD11b, and F4/80 indicated that the majority were myeloid DCs, although a proportion were CD11c(-) F4/80(+), suggesting that macrophages were an additional source of IL-12 in the skin.
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Affiliation(s)
- Karen G Hogg
- Department of Biology (Area 5), The University of York, United Kingdom
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Muraille E, De Trez C, Pajak B, Torrentera FA, De Baetselier P, Leo O, Carlier Y. Amastigote load and cell surface phenotype of infected cells from lesions and lymph nodes of susceptible and resistant mice infected with Leishmania major. Infect Immun 2003; 71:2704-15. [PMID: 12704145 PMCID: PMC153240 DOI: 10.1128/iai.71.5.2704-2715.2003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cells of the dendritic cell (DC) lineage, by their unique ability to stimulate naive T cells, may be of crucial importance in the development of protective immune responses to Leishmania parasites. The aim of this study was to compare the impact of L. major infection on DCs in BALB/c (susceptible, developing Th2 responses), C57BL/6 (resistant, developing Th1 responses), and tumor necrosis factor (TNF)(-/-) C57BL/6 mice (susceptible, developing delayed and reduced Th1 responses). We analyzed by immunohistochemistry the phenotype of infected cells in vivo. Granulocytes (GR1(+)) and macrophages (CD11b(+)) appear as the mainly infected cells in primary lesions. In contrast, cells expressing CD11c, a DC specific marker, are the most frequently infected cells in draining lymph nodes of all mice tested. These infected CD11c(+) cells harbored a particular morphology and cell surface phenotype in infected C57BL/6 and BALB/c mice. CD11c(+) infected cells from C57BL/6 and TNF(-/-) C57BL/6 mice displayed a weak parasitic load and a dendritic morphology and frequently expressed CD11b or F4/80 myeloid differentiation markers. In contrast, some CD11c(+) infected cells from BALB/c mice were multinucleated giant cells. Giant cells presented a dramatic accumulation of parasites and differentiation markers were not detectable at their surface. In all mice, lymph node CD11c(+) infected cells expressed a low major histocompatibility complex II level and no detectable CD86 expression. Our results suggest that infected CD11c(+) DC-like cells might constitute a reservoir of parasites in lymph nodes.
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Affiliation(s)
- Eric Muraille
- Laboratory of Parasitology, Université Libre de Bruxelles, Erasme, Brussels, Belgium
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