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Lee HJ, Georgiadou A, Otto TD, Levin M, Coin LJ, Conway DJ, Cunnington AJ. Transcriptomic Studies of Malaria: a Paradigm for Investigation of Systemic Host-Pathogen Interactions. Microbiol Mol Biol Rev 2018; 82:e00071-17. [PMID: 29695497 PMCID: PMC5968457 DOI: 10.1128/mmbr.00071-17] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Transcriptomics, the analysis of genome-wide RNA expression, is a common approach to investigate host and pathogen processes in infectious diseases. Technical and bioinformatic advances have permitted increasingly thorough analyses of the association of RNA expression with fundamental biology, immunity, pathogenesis, diagnosis, and prognosis. Transcriptomic approaches can now be used to realize a previously unattainable goal, the simultaneous study of RNA expression in host and pathogen, in order to better understand their interactions. This exciting prospect is not without challenges, especially as focus moves from interactions in vitro under tightly controlled conditions to tissue- and systems-level interactions in animal models and natural and experimental infections in humans. Here we review the contribution of transcriptomic studies to the understanding of malaria, a parasitic disease which has exerted a major influence on human evolution and continues to cause a huge global burden of disease. We consider malaria a paradigm for the transcriptomic assessment of systemic host-pathogen interactions in humans, because much of the direct host-pathogen interaction occurs within the blood, a readily sampled compartment of the body. We illustrate lessons learned from transcriptomic studies of malaria and how these lessons may guide studies of host-pathogen interactions in other infectious diseases. We propose that the potential of transcriptomic studies to improve the understanding of malaria as a disease remains partly untapped because of limitations in study design rather than as a consequence of technological constraints. Further advances will require the integration of transcriptomic data with analytical approaches from other scientific disciplines, including epidemiology and mathematical modeling.
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Affiliation(s)
- Hyun Jae Lee
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | | | - Thomas D Otto
- Centre of Immunobiology, University of Glasgow, Glasgow, United Kingdom
| | - Michael Levin
- Section of Paediatrics, Imperial College, London, United Kingdom
| | - Lachlan J Coin
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - David J Conway
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Haddad M. Adenosine A2B Receptors - Mediated Induction of Interleukin-6 in Skeletal Muscle Cells. Turk J Pharm Sci 2017; 14:19-28. [PMID: 32454590 DOI: 10.4274/tjps.08108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 07/28/2016] [Indexed: 01/10/2023]
Abstract
Objectives Inflammatory response and cytokine activation are markedly stimulated in skeletal muscle during various conditions. Interleukin-6 (IL-6), a pro-inflammatory cytokine, has pleiotropic effects on skeletal muscle. Adenosine, released by all cell types, binds to a class of G protein-coupled receptors to induce various skeletal muscle effects. The aim of this work was to investigate whether activation of adenosine receptors, particularly adenosine A2B receptors, could stimulate IL-6 gene expression in rat L6 skeletal muscle cells. Materials and Methods The rat L6 skeletal muscle cells were cultured in 25 cm2 flasks. These differentiated cells were treated and then quantitative reverse transcription-polymerase chain reaction (Probe-based) was used to analyze IL-6 gene expression level among different treatment conditions. Results Adenosine-5'-N-ethyluronamide (NECA), a stable adenosine analogue, concentration- and time-dependently stimulates IL-6 gene expression in skeletal muscle cells. The effect of NECA is inhibited by a selective adenosine A2B receptor antagonist, PSB 603. By using cyclic adenosine monophosphate (cAMP)-arising reagent forskolin, cAMP is found to be involved in the up-regulation of IL-6 induction. Conclusion Here, a novel relationship between adenosine and IL-6 up-regulation has been demonstrated for the first time; IL-6 up-regulation induced by NECA is mediated by adenosine A2B receptor activation in skeletal muscle and is dependent on mainly a cAMP pathway. Adenosine A2B receptors are, thus, potentially important pharmacological targets in treating inflammation and related diseases in skeletal muscle tissues.
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Affiliation(s)
- Mansour Haddad
- Department Of Clinical Sciences, Faculty Of Pharmacy, Philadelphia University, Amman, Jordan
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Flórez-Vargas O, Bramhall M, Noyes H, Cruickshank S, Stevens R, Brass A. The quality of methods reporting in parasitology experiments. PLoS One 2014; 9:e101131. [PMID: 25076044 PMCID: PMC4116335 DOI: 10.1371/journal.pone.0101131] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 06/03/2014] [Indexed: 12/23/2022] Open
Abstract
There is a growing concern both inside and outside the scientific community over the lack of reproducibility of experiments. The depth and detail of reported methods are critical to the reproducibility of findings, but also for making it possible to compare and integrate data from different studies. In this study, we evaluated in detail the methods reporting in a comprehensive set of trypanosomiasis experiments that should enable valid reproduction, integration and comparison of research findings. We evaluated a subset of other parasitic (Leishmania, Toxoplasma, Plasmodium, Trichuris and Schistosoma) and non-parasitic (Mycobacterium) experimental infections in order to compare the quality of method reporting more generally. A systematic review using PubMed (2000-2012) of all publications describing gene expression in cells and animals infected with Trypanosoma spp was undertaken based on PRISMA guidelines; 23 papers were identified and included. We defined a checklist of essential parameters that should be reported and have scored the number of those parameters that are reported for each publication. Bibliometric parameters (impact factor, citations and h-index) were used to look for association between Journal and Author status and the quality of method reporting. Trichuriasis experiments achieved the highest scores and included the only paper to score 100% in all criteria. The mean of scores achieved by Trypanosoma articles through the checklist was 65.5% (range 32-90%). Bibliometric parameters were not correlated with the quality of method reporting (Spearman's rank correlation coefficient <-0.5; p>0.05). Our results indicate that the quality of methods reporting in experimental parasitology is a cause for concern and it has not improved over time, despite there being evidence that most of the assessed parameters do influence the results. We propose that our set of parameters be used as guidelines to improve the quality of the reporting of experimental infection models as a pre-requisite for integrating and comparing sets of data.
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Affiliation(s)
- Oscar Flórez-Vargas
- Bio-health Informatics Group, School of Computer Science, University of Manchester, Manchester, United Kingdom
| | - Michael Bramhall
- Bio-health Informatics Group, School of Computer Science, University of Manchester, Manchester, United Kingdom
| | - Harry Noyes
- School of Biological Science, University of Liverpool, Liverpool, United Kingdom
| | - Sheena Cruickshank
- Manchester Immunology Group, Faculty of Life Science, University of Manchester, Manchester, United Kingdom
| | - Robert Stevens
- Bio-health Informatics Group, School of Computer Science, University of Manchester, Manchester, United Kingdom
| | - Andy Brass
- Bio-health Informatics Group, School of Computer Science, University of Manchester, Manchester, United Kingdom
- Manchester Immunology Group, Faculty of Life Science, University of Manchester, Manchester, United Kingdom
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Nakashioya H, Nakano K, Watanabe N, Miyasaka N, Matsushita S, Kohsaka H. Therapeutic effect of D1-like dopamine receptor antagonist on collagen-induced arthritis of mice. Mod Rheumatol 2014. [DOI: 10.3109/s10165-010-0387-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Hiroki Nakashioya
- Global Center of Excellence (GCOE) Program, Department of Medicine and Rheumatology, Graduate School of Medical and Dental Sciences, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University,
1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
- Department of Biomolecular Science, Faculty of Science, Toho University,
2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan
- Clinical Immunology, RIKEN Research Center of Allergy and Immunology,
1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Kazuhisa Nakano
- Department of Allergy and Immunology, Faculty of Medicine, Saitama Medical University,
38 Morohongo, Moroyama-cho, Iruma-gun, Saitama 350-0451, Japan
| | - Naoko Watanabe
- Department of Biomolecular Science, Faculty of Science, Toho University,
2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan
| | - Nobuyuki Miyasaka
- Global Center of Excellence (GCOE) Program, Department of Medicine and Rheumatology, Graduate School of Medical and Dental Sciences, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University,
1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Sho Matsushita
- Department of Allergy and Immunology, Faculty of Medicine, Saitama Medical University,
38 Morohongo, Moroyama-cho, Iruma-gun, Saitama 350-0451, Japan
| | - Hitoshi Kohsaka
- Global Center of Excellence (GCOE) Program, Department of Medicine and Rheumatology, Graduate School of Medical and Dental Sciences, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University,
1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
- Clinical Immunology, RIKEN Research Center of Allergy and Immunology,
1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
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Del Portillo HA, Ferrer M, Brugat T, Martin-Jaular L, Langhorne J, Lacerda MVG. The role of the spleen in malaria. Cell Microbiol 2012; 14:343-55. [PMID: 22188297 DOI: 10.1111/j.1462-5822.2011.01741.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The spleen is a complex organ that is perfectly adapted to selectively filtering and destroying senescent red blood cells (RBCs), infectious microorganisms and Plasmodium-parasitized RBCs. Infection by malaria is the most common cause of spleen rupture and splenomegaly, albeit variably, a landmark of malaria infection. Here, the role of the spleen in malaria is reviewed with special emphasis in lessons learned from human infections and mouse models.
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Affiliation(s)
- Hernando A Del Portillo
- Barcelona Centre for International Health Research (CRESIB, Hospital Clinic-Universitat de Barcelona), Barcelona, Spain.
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Gazarini ML, Beraldo FH, Almeida FM, Bootman M, Da Silva AM, Garcia CRS. Melatonin triggers PKA activation in the rodent malaria parasite Plasmodium chabaudi. J Pineal Res 2011; 50:64-70. [PMID: 20964707 DOI: 10.1111/j.1600-079x.2010.00810.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Calcium (Ca(2+) ) is a critical regulator of many aspects of the Plasmodium reproductive cycle. In particular, intra-erythrocyte Plasmodium parasites respond to circulating levels of the melatonin in a process mediated partly by intracellular Ca(2+) . Melatonin promotes the development and synchronicity of parasites, thereby enhancing their spread and worsening the clinical implications. The signalling mechanisms underlying the effects of melatonin are not fully established, although both Ca(2+) and cyclic AMP (cAMP) have been implicated. Furthermore, it is not clear whether different strains of Plasmodium use the same, or divergent, signals to control their development. The aim of this study was to explore the signalling mechanisms engaged by melatonin in P. chabaudi, a virulent rodent parasite. Using parasites at the throphozoite stage acutely isolated from mice erythrocytes, we demonstrate that melatonin triggers cAMP production and protein kinase A (PKA) activation. Interestingly, the stimulation of cAMP/PKA signalling by melatonin was dependent on elevation of Ca(2+) within the parasite, because buffering Ca(2+) changes using the chelator BAPTA prevented cAMP production in response to melatonin. Incubation with melatonin evoked robust Ca(2+) signals within the parasite, as did the application of a membrane-permeant analogue of cAMP. Our data suggest that P. chabaudi engages both Ca(2+) and cAMP signalling systems when stimulated by melatonin. Furthermore, there is positive feedback between these messengers, because Ca(2+) evokes cAMP elevation and vice versa. Melatonin more than doubled the observed extent of parasitemia, and the increase in cAMP concentration and PKA activation was essential for this effect. These data support the possibility to use melatonin antagonists or derivates in therapeutic approach.
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Affiliation(s)
- Marcos L Gazarini
- Departamento de Biociências, Universidade Federal de São Paulo, Santos, SP, Brasil
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Nakashioya H, Nakano K, Watanabe N, Miyasaka N, Matsushita S, Kohsaka H. Therapeutic effect of D1-like dopamine receptor antagonist on collagen-induced arthritis of mice. Mod Rheumatol 2010; 21:260-6. [PMID: 21188452 DOI: 10.1007/s10165-010-0387-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 11/14/2010] [Indexed: 10/18/2022]
Abstract
Dopamine activates D1-like and D2-like receptors (D1R and D2R). While D1R antagonists have ameliorated the severity of disease in some experimental autoimmune models of mice by promoting interferon (IFN)-γ and inhibiting interleukin (IL)-17 production by T cells, dopamine effects in the immune system are reportedly diverse. To investigate the impact of D1R blockade on an animal model of rheumatoid arthritis (RA), DBA/1 mice with collagen-induced arthritis (CIA) were treated with a selective D1R antagonist, SCH23390, after the primary immunization. This treatment suppressed the severity of the CIA. Nevertheless, serum levels of antibodies to type II collagen were not affected by the treatment. Th1/Th17 differentiation of splenic T cells in the treated animals was not biased. In vitro, when bone marrow-derived macrophages were stimulated in the presence of the D1R antagonist SCH23390, alteration of inflammatory cytokine expression was not observed, but their in vitro differentiation to osteoclasts was inhibited. Co-administration of a selective D1R agonist, A68930, abrogated the in vivo anti-arthritic effect and the in vitro suppression of osteoclastogenesis by the D1R antagonist. Our results argue that D1R blockade is potentially a new approach to the treatment of RA. Its effect could be partly attributable to the inhibition of osteoclastogenesis.
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Affiliation(s)
- Hiroki Nakashioya
- Global Center of Excellence (GCOE) Program, Department of Medicine and Rheumatology, Graduate School of Medical and Dental Sciences, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
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Bettiol E, Carapau D, Galan-Rodriguez C, Ocaña-Morgner C, Rodriguez A. Dual effect of Plasmodium-infected erythrocytes on dendritic cell maturation. Malar J 2010; 9:64. [PMID: 20193084 PMCID: PMC2842284 DOI: 10.1186/1475-2875-9-64] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Accepted: 03/01/2010] [Indexed: 11/13/2022] Open
Abstract
Background Infection with Plasmodium is the cause of malaria, a disease characterized by a high inflammatory response in the blood. Dendritic cells (DC) participate in both adaptive and innate immune responses, influencing the generation of inflammatory responses. DC can be activated through different receptors, which recognize specific molecules in microbes and induce the maturation of DC. Methods Using Plasmodium yoelii, a rodent malaria model, the effect of Plasmodium-infected erythrocytes on DC maturation and TLR responses have been analysed. Results It was found that intact erythrocytes infected with P. yoelii do not induce maturation of DC unless they are lysed, suggesting that accessibility of parasite inflammatory molecules to their receptors is a key issue in the activation of DC by P. yoelii. This activation is independent of MyD88. It was also observed that pre-incubation of DC with intact P. yoelii-infected erythrocytes inhibits the maturation response of DC to other TLR stimuli. The inhibition of maturation of DC is reversible, parasite-specific and increases with the stage of parasite development, with complete inhibition induced by schizonts (mature infected erythrocytes). Plasmodium yoelii-infected erythrocytes induce a broad inhibitory effect rendering DC non-responsive to ligands for TLR2, TLR3, TLR4, TLR5, TLR7 and TLR9. Conclusions Despite the presence of inflammatory molecules within Plasmodium-infected erythrocytes, which are probably responsible for DC maturation induced by lysates, intact Plasmodium-infected erythrocytes induce a general inhibition of TLR responsiveness in DC. The observed effect on DC could play an important role in the pathology and suboptimal immune response observed during the disease. These results help to explain why immune functions are altered during malaria, and provide a system for the identification of a parasite-derived broad inhibitor of TLR-mediated signaling pathways.
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Affiliation(s)
- Esther Bettiol
- Department of Medical Parasitology, New York University School of Medicine, 341 East 25th street, New York, NY 10010, USA
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Feng W, Song Y, Chen C, Lu ZZ, Zhang Y. Stimulation of adenosine A(2B) receptors induces interleukin-6 secretion in cardiac fibroblasts via the PKC-delta-P38 signalling pathway. Br J Pharmacol 2009; 159:1598-607. [PMID: 20050850 DOI: 10.1111/j.1476-5381.2009.00558.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND AND PURPOSE Inflammatory response and cytokine activation are markedly stimulated after myocardial infarction, and contribute to cardiac remodelling. Interleukin-6 (IL-6), a pro-inflammatory cytokine, has pleiotropic effects on cardiac remodelling. Adenosine, released by all cell types, binds to a class of G protein-coupled receptors to induce various cardiovascular effects. The aim of this work was to investigate whether activation of adenosine receptors, particularly A(2B) adenosine receptors, could stimulate IL-6 secretion in cardiac fibroblasts (CFs). EXPERIMENTAL APPROACH elisa was used to assess IL-6 concentration in supernatant, and immunostaining was used to analyse IL-6 protein level in CFs. The levels of phosphorylated and total p38, extracellular signal-regulated kinase, c-Jun N-terminal kinase and protein kinase C-delta (PKC-delta) were determined by Western blot analysis. KEY RESULTS Adenosine-5'-N-ethyluronamide (NECA), a stable adenosine analogue, dose- and time-dependently stimulated IL-6 secretion in CFs. The effect of NECA was dose-dependently inhibited by an A(2B) antagonist, and silencing of the A(2B) receptor also inhibited IL-6 secretion. By using PKC isoform-selective inhibitors and translocation peptide inhibitors, the PKC-delta isoform was found to be involved in the up-regulation of IL-6 production. Inhibition of p38 by SB203580, and adenoviral transfer of dominant-negative p38 inhibited NECA-induced IL-6 production. Furthermore, PKC-delta functioned as an upstream regulator of p38 MAPK in this process. CONCLUSIONS AND IMPLICATIONS We demonstrated a novel relationship between adenosine and IL-6 secretion, in that IL-6 secretion induced by NECA was mediated by adenosine A(2B) receptor activation in CFs and was dependent on a PKCdelta-P38 pathway.
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Affiliation(s)
- Wei Feng
- Institute of Vascular Medicine, Peking University Third Hospital, Ministry of Education, Beijing, China
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Orengo JM, Wong KA, Ocaña-Morgner C, Rodriguez A. A Plasmodium yoelii soluble factor inhibits the phenotypic maturation of dendritic cells. Malar J 2008; 7:254. [PMID: 19077314 PMCID: PMC2614434 DOI: 10.1186/1475-2875-7-254] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Accepted: 12/15/2008] [Indexed: 02/02/2023] Open
Abstract
Background Infection with the protozoan parasite Plasmodium is the cause of malaria. Plasmodium infects host erythrocytes causing the pathology of the disease. Plasmodium-infected erythrocytes can modulate the maturation of dendritic cells (DCs) and alter their capacity to activate T cells. Methods Mice infected with Plasmodium yoelii and isolated P. yoelii-infected erythrocytes were used to study their effect on the maturation of mouse dendritic cells. Results DCs are not able to mature in response to LPS injection during the late stage of P. yoelii infection in mice, indicating impaired functionality of these cells in vivo. P. yoelii- infected erythrocytes inhibit the maturation of DCs in vitro in a dose-dependent manner, which is consistent with the inhibition found during late infection when parasite burden is highest. The inhibition of DC maturation and the cytokine secretion profile of DCs are modulated by soluble factors released by P. yoelii-infected erythrocytes. A small, heat-stable, non-hydrophobic molecule of P. yoelii-infected erythrocytes rapidly inhibits the LPS induced phenotypic maturation of DCs in a reversible manner. Conclusion These findings add evidence to the malaria associated immune suppression in vivo and in vitro and provide insight into the nature and mechanism of the Plasmodium factor(s) responsible for altering DC functions.
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Affiliation(s)
- Jamie M Orengo
- Department of Medical Parasitology, New York University School of Medicine, New York, NY 10010, USA.
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Abstract
Infection with Plasmodium parasites (malaria) contributes greatly to morbidity and mortality in affected areas. Interaction of the protozoan with the immune system has a critical role in the pathogenesis of the disease, but may also hold a key to containing parasite numbers through specific immune responses, which vaccine development aims to harness. A central player in the generation of such immune responses is the dendritic cell. However, Plasmodium parasites appear to have profound activating and suppressing effects on dendritic cell function, which may enhance immunopathology or facilitate the parasite's survival by depressing beneficial immunity. Furthermore, immune responses to other infections and vaccines may be impaired. A greater understanding of the effects of the parasite on dendritic cells will contribute to insight and potential defeat of this infectious disease.
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Affiliation(s)
- Stephen M Todryk
- Biomolecular & Biomedical Research Centre, School of Applied Sciences, Northumbria University, Newcastle-upon-Tyne, NE1 8ST, UK.
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Ocaña-Morgner C, Wong KA, Rodriguez A. Interactions between dendritic cells and CD4+ T cells during Plasmodium infection. Malar J 2008; 7:88. [PMID: 18495039 PMCID: PMC2423365 DOI: 10.1186/1475-2875-7-88] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Accepted: 05/21/2008] [Indexed: 12/02/2022] Open
Abstract
Background During infection, dendritic cells (DCs) encounter pathogenic microorganisms that can modulate their function and shape the T cell responses generated. During the process of T cell activation, DCs establish strong, long-lasting interactions with naïve T cells. Methods Using a mouse malaria model, the interactions of DCs and naïve CD4+ T cells have been analysed. Results DCs, either incubated in vitro with infected erythrocytes or isolated from infected mice, are able to present exogenous antigens by MHC-II, but are not able to establish prolonged effective interactions with naïve CD4+ T cells and do not induce T cell activation. It was also found that effective T cell activation of naïve CD4+ T cells is impaired during late Plasmodium yoelii infection. Conclusion These data may provide a mechanism for the lack of effective adaptive immune responses induced by the Plasmodium parasite.
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Affiliation(s)
- Carlos Ocaña-Morgner
- New York University School of Medicine, Department of Medical Parasitology, 341 E 25th street, New York, NY 10010, USA.
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Wong KA, Rodriguez A. Plasmodium infection and endotoxic shock induce the expansion of regulatory dendritic cells. THE JOURNAL OF IMMUNOLOGY 2008; 180:716-26. [PMID: 18178809 DOI: 10.4049/jimmunol.180.2.716] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
During an acute Plasmodium infection, uncontrolled proinflammatory responses can cause morbidity and mortality. Regulation of this response is required to prevent immunopathology. We therefore decided to investigate a recently characterized subset of regulatory dendritic cells (DCs) that expresses low levels of CD11c and high levels of CD45RB. During a Plasmodium yoelii infection, these regulatory CD11clowCD45RBhigh DCs become the prevalent CD11c-expressing cells in the spleen, overtaking the conventional CD11chigh DCs. Furthermore, the regulatory CD11clowCD45RBhigh DCs induce IL-10-expressing CD4 T cells. A similar change in splenic DC subsets is seen when mice are injected with sublethal doses of LPS, suggesting that shifting the splenic DC subsets in favor of regulatory CD11clowCD45RBhigh DCs can be triggered solely by a high inflammatory stimulus. This is the first time regulatory DCs have been observed in a natural immune response to an infectious disease or endotoxic shock.
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Affiliation(s)
- Kurt A Wong
- Department of Medical Parasitology, New York University School of Medicine, New York, NY 10010, USA
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Orengo JM, Evans JE, Bettiol E, Leliwa-Sytek A, Day K, Rodriguez A. Plasmodium-induced inflammation by uric acid. PLoS Pathog 2008; 4:e1000013. [PMID: 18369465 PMCID: PMC2267007 DOI: 10.1371/journal.ppat.1000013] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Accepted: 01/25/2008] [Indexed: 12/22/2022] Open
Abstract
Infection of erythrocytes with the Plasmodium parasite causes the pathologies associated with malaria, which result in at least one million deaths annually. The rupture of infected erythrocytes triggers an inflammatory response, which is induced by parasite-derived factors that still are not fully characterized. Induced secretion of inflammatory cytokines by these factors is considered a major cause of malaria pathogenesis. In particular, the inflammatory cytokine tumor necrosis factor (TNF) is thought to mediate most of the life-threatening pathologies of the disease. Here we describe the molecular characterization of a novel pathway that results in the secretion of TNF by host cells. We found that erythrocytes infected by Plasmodium accumulate high concentrations of hypoxanthine and xanthine. Degradation of Plasmodium-derived hypoxanthine/xanthine results in the formation of uric acid, which triggers the secretion of TNF. Since uric acid is considered a "danger signal" released by dying cells to alert the immune system, Plasmodium appears to have co-evolved to exploit this warning system. Identifying the mechanisms used by the parasite to induce the host inflammatory response is essential to develop urgently needed therapies against this disease.
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Affiliation(s)
- Jamie M. Orengo
- Department of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - James E. Evans
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Esther Bettiol
- Department of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - Aleksandra Leliwa-Sytek
- Department of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - Karen Day
- Department of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - Ana Rodriguez
- Department of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
- * E-mail:
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Sherman IW. References. ADVANCES IN PARASITOLOGY 2008. [DOI: 10.1016/s0065-308x(08)00430-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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