1
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NF kappa B regulator Bcl3 controls development and function of classical dendritic cells required for resistance to Toxoplasma gondii. PLoS Pathog 2022; 18:e1010502. [DOI: 10.1371/journal.ppat.1010502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 11/11/2022] [Accepted: 10/18/2022] [Indexed: 11/13/2022] Open
Abstract
The atypical IκB family member Bcl3 associates with p50/NF-κB1 or p52/NF-κB2 homodimers in the nucleus, and positively or negatively modulates transcription in a context-dependent manner. In mice lacking Bcl3 globally or specifically in CD11c+ cells, we previously reported that Toxoplasma gondii infection is uniformly fatal and is associated with an impaired Th1 immune response. Since Bcl3 expression in dendritic cells (DC) is pivotal for antigen presentation and since classical DCs (cDC) are major antigen presenting cells, we investigated the role of Bcl3 specifically in cDCs in vivo by crossing Zbtb46 cre mice with Bcl3flx/flx mice. Bcl3flx/flx Zbtb46 cre mice were as susceptible to lethal T. gondii infection as total Bcl3-/- mice and generated poor Th1 immune responses. Consistent with this, compared to wildtype controls, splenic Xcr1+ Bcl3-deficient cDC1 cells were defective in presenting Ova antigen to OT-I cells both for Ova257-264 peptide and after infection with Ovalbumin-expressing T. gondii. Moreover, splenic CD4+ and CD8+ T cells from infected Bcl3flx/flx Zbtb46 cre mice exhibited decreased T. gondii-specific priming as revealed by both reduced cytokine production and reduced T. gondii-specific tetramer staining. In vitro differentiation of cDCs from bone marrow progenitors also revealed Bcl3-dependent cDC-specific antigen-presentation activity. Consistent with this, splenocyte single cell RNA seq (scRNAseq) in infected mice revealed Bcl3-dependent expression of genes involved in antigen processing in cDCs. We also identified by scRNAseq, a unique Bcl3-dependent hybrid subpopulation of Zbtb46+ DCs co-expressing the monocyte/macrophage transcription factor Lysozyme M. This subpopulation exhibited Bcl3-dependent expansion after infection. Likewise, by flow cytometry we identified two T. gondii-induced hybrid subpopulations of Bcl3-dependent cDC1 and cDC2 cells both expressing monocyte/macrophage markers, designated as icDC1 and icDC2. Together, our results indicate that Bcl3 in classical DCs is a major determinant of protective T cell responses and survival in T. gondii-infection.
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2
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Griffith MB, Pearce CS, Heaslip AT. Dense granule biogenesis, secretion, and function in Toxoplasma gondii. J Eukaryot Microbiol 2022; 69:e12904. [PMID: 35302693 PMCID: PMC9482668 DOI: 10.1111/jeu.12904] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Toxoplasma gondii is an obligate intracellular parasite and the causative agent of Toxoplasmosis. A key to understanding and treating the disease lies with determining how the parasite can survive and replicate within cells of its host. Proteins released from specialized secretory vesicles, named the dense granules (DGs), have diverse functions that are critical for adapting the intracellular environment, and are thus key to survival and pathogenicity. In this review, we describe the current understanding and outstanding questions regarding dense granule biogenesis, trafficking, and regulation of secretion. In addition, we provide an overview of dense granule protein ("GRA") function upon secretion, with a focus on proteins that have recently been identified.
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Affiliation(s)
- Michael B Griffith
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Camille S Pearce
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Aoife T Heaslip
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
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3
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Wang Y, Tsitsiklis A, Devoe S, Gao W, Chu HH, Zhang Y, Li W, Wong WK, Deane CM, Neau D, Slansky JE, Thomas PG, Robey EA, Dai S. Peptide Centric Vβ Specific Germline Contacts Shape a Specialist T Cell Response. Front Immunol 2022; 13:847092. [PMID: 35967379 PMCID: PMC9372435 DOI: 10.3389/fimmu.2022.847092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 05/31/2022] [Indexed: 11/15/2022] Open
Abstract
Certain CD8 T cell responses are particularly effective at controlling infection, as exemplified by elite control of HIV in individuals harboring HLA-B57. To understand the structural features that contribute to CD8 T cell elite control, we focused on a strongly protective CD8 T cell response directed against a parasite-derived peptide (HF10) presented by an atypical MHC-I molecule, H-2Ld. This response exhibits a focused TCR repertoire dominated by Vβ2, and a representative TCR (TG6) in complex with Ld-HF10 reveals an unusual structure in which both MHC and TCR contribute extensively to peptide specificity, along with a parallel footprint of TCR on its pMHC ligand. The parallel footprint is a common feature of Vβ2-containing TCRs and correlates with an unusual Vα-Vβ interface, CDR loop conformations, and Vβ2-specific germline contacts with peptides. Vβ2 and Ld may represent "specialist" components for antigen recognition that allows for particularly strong and focused T cell responses.
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Affiliation(s)
- Yang Wang
- Department of Pharmaceutical Sciences, University of Colorado School of Pharmacy, Aurora, CO, United States
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Alexandra Tsitsiklis
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, United States
| | - Stephanie Devoe
- Department of Pharmaceutical Sciences, University of Colorado School of Pharmacy, Aurora, CO, United States
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Wei Gao
- Department of Pharmaceutical Sciences, University of Colorado School of Pharmacy, Aurora, CO, United States
- Biological Physics Laboratory, College of Science, Beijing Forestry University, Beijing, China
| | - H. Hamlet Chu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, United States
| | - Yan Zhang
- Department of Pharmaceutical Sciences, University of Colorado School of Pharmacy, Aurora, CO, United States
| | - Wei Li
- Department of Pharmaceutical Sciences, University of Colorado School of Pharmacy, Aurora, CO, United States
| | - Wing Ki Wong
- Department of Statistics, University of Oxford, Oxford, United Kingdom
| | | | - David Neau
- Department of Chemistry and Chemical Biology, Northeastern Collaborative Access Team (NE-CAT), Advanced Photon Source, Argonne National Laboratory, Cornell University, Argonne, IL, United States
| | - Jill E. Slansky
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Paul G. Thomas
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN, United States
| | - Ellen A. Robey
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, United States
| | - Shaodong Dai
- Department of Pharmaceutical Sciences, University of Colorado School of Pharmacy, Aurora, CO, United States
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States
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Zorgi NE, Arruda LV, Paladine I, Roque GAS, Araújo TF, Brocchi M, Barral M, Sanchiz Á, Requena JM, Abánades DR, Giorgio S. Leishmania infantum transfected with toxic plasmid induces protection in mice infected with wild type L. infantum or L. amazonensis. Mol Immunol 2020; 127:95-106. [PMID: 32949849 DOI: 10.1016/j.molimm.2020.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/08/2020] [Accepted: 08/13/2020] [Indexed: 12/13/2022]
Abstract
Leishmania infantum infection may cause visceral leishmaniasis (VL), a fatal disease having worldwide distribution, that may be silent or asymptomatic. The latter indicates that immunity is naturally developed in some individuals, and, therefore, a vaccine against VL would be possible. Molecular mechanisms of gene expression are being understood in Leishmania, and this knowledge may be useful for vaccine development. The aim of this study was developing an attenuated strain by regulating the expression of toxic proteins in a stage specific manner. For that purpose, the 3' UTR of an amastin gene, known by its increased expression in the amastigote phase, was selected for direct the expression of exogenous proteins. This construct (pFL-AMA), firstly, was proved effective for the expression of mCherry specifically in the intracellular form of L. infantum, as demonstrated by fluorescence microscopy, flow cytometry and Western blotting. Afterwards, mCherry coding sequence was replaced, in the pFL-AMA plasmid, by either egg avidin or the active form of bovine trypsin. Viability of transfected parasites was evaluated in promastigote axenic cultures and in in vitro infection of macrophages. Both lines of transfected parasites showed a limited capacity to multiply inside macrophages. BALB/c mice were inoculated intraperitoneally (i.p.) with a single dose consisting of 2 × 106L. infantum promastigotes transfected with plasmids bearing the toxic genes. After 10 weeks post-inoculation, no parasites were recovered by limiting dilution in either liver or spleen, but a specific immunological response was detected. The immunization with transfected parasites induced cellular and humoral immune responses with activation of TCD4+, TCD8+ and B cells, having a TH1-type response with increased levels of pro-inflammatory cytokines such as IFN-γ, TNF-α and IL-6. In parallel groups of mice, a challenge consisting on 1 × 106 virulent parasites of either L. infantum (inoculated i.p.) or L. amazonensis subcutaneously (s.c.) was performed. Vaccinated mice, challenged with L. infantum, showed lower parasite burdens in liver, spleen and bone marrow than infected mice with WT L. infantum (non-vaccinated); similarly, vaccinated mice developed smaller footpad inflammation than control group. These data support this strategy as an efficient immunization system aimed to the development of vaccines against different forms of leishmaniasis.
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Affiliation(s)
- Nahiara Esteves Zorgi
- Department of Animal Biology, Institute of Biology, State University of Campinas, Campinas, São Paulo, Brazil.
| | - Leonardo V Arruda
- Research Center Gonçalo Moniz, Foundation Oswaldo Cruz, Salvador, Bahia, Brazil
| | - Izadora Paladine
- Department of Animal Biology, Institute of Biology, State University of Campinas, Campinas, São Paulo, Brazil
| | - Guilherme A S Roque
- Department of Animal Biology, Institute of Biology, State University of Campinas, Campinas, São Paulo, Brazil
| | - Thalita F Araújo
- Department of Animal Biology, Institute of Biology, State University of Campinas, Campinas, São Paulo, Brazil
| | - Marcelo Brocchi
- Department of Microbiology and Immunology, Institute of Biology, State University of Campinas, Campinas, São Paulo, Brazil
| | - Manoel Barral
- Research Center Gonçalo Moniz, Foundation Oswaldo Cruz, Salvador, Bahia, Brazil; School of Medicine of University Federal of Bahia, Salvador, Bahia, Brazil
| | - África Sanchiz
- Departament of Molecular Biology, Center for Molecular Biology "Severo Ochoa", Autonomous University of Madrid, Madrid, Spain
| | - José María Requena
- Departament of Molecular Biology, Center for Molecular Biology "Severo Ochoa", Autonomous University of Madrid, Madrid, Spain
| | - Daniel R Abánades
- Department of Animal Biology, Institute of Biology, State University of Campinas, Campinas, São Paulo, Brazil
| | - Selma Giorgio
- Department of Animal Biology, Institute of Biology, State University of Campinas, Campinas, São Paulo, Brazil
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5
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Kongsomboonvech AK, Rodriguez F, Diep AL, Justice BM, Castallanos BE, Camejo A, Mukhopadhyay D, Taylor GA, Yamamoto M, Saeij JPJ, Reese ML, Jensen KDC. Naïve CD8 T cell IFNγ responses to a vacuolar antigen are regulated by an inflammasome-independent NLRP3 pathway and Toxoplasma gondii ROP5. PLoS Pathog 2020; 16:e1008327. [PMID: 32853276 PMCID: PMC7480859 DOI: 10.1371/journal.ppat.1008327] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 09/09/2020] [Accepted: 07/05/2020] [Indexed: 12/31/2022] Open
Abstract
Host resistance to Toxoplasma gondii relies on CD8 T cell IFNγ responses, which if modulated by the host or parasite could influence chronic infection and parasite transmission between hosts. Since host-parasite interactions that govern this response are not fully elucidated, we investigated requirements for eliciting naïve CD8 T cell IFNγ responses to a vacuolar resident antigen of T. gondii, TGD057. Naïve TGD057 antigen-specific CD8 T cells (T57) were isolated from transnuclear mice and responded to parasite-infected bone marrow-derived macrophages (BMDMs) in an antigen-dependent manner, first by producing IL-2 and then IFNγ. T57 IFNγ responses to TGD057 were independent of the parasite’s protein export machinery ASP5 and MYR1. Instead, host immunity pathways downstream of the regulatory Immunity-Related GTPases (IRG), including partial dependence on Guanylate-Binding Proteins, are required. Multiple T. gondii ROP5 isoforms and allele types, including ‘avirulent’ ROP5A from clade A and D parasite strains, were able to suppress CD8 T cell IFNγ responses to parasite-infected BMDMs. Phenotypic variance between clades B, C, D, F, and A strains suggest T57 IFNγ differentiation occurs independently of parasite virulence or any known IRG-ROP5 interaction. Consistent with this, removal of ROP5 is not enough to elicit maximal CD8 T cell IFNγ production to parasite-infected cells. Instead, macrophage expression of the pathogen sensors, NLRP3 and to a large extent NLRP1, were absolute requirements. Other members of the conventional inflammasome cascade are only partially required, as revealed by decreased but not abrogated T57 IFNγ responses to parasite-infected ASC, caspase-1/11, and gasdermin D deficient cells. Moreover, IFNγ production was only partially reduced in the absence of IL-12, IL-18 or IL-1R signaling. In summary, T. gondii effectors and host machinery that modulate parasitophorous vacuolar membranes, as well as NLR-dependent but inflammasome-independent pathways, determine the full commitment of CD8 T cells IFNγ responses to a vacuolar antigen. Parasites are excellent “students” of our immune system as they can deflect, antagonize and confuse the immune response making it difficult to vaccinate against these pathogens. In this report, we analyzed how a widespread parasite of mammals, Toxoplasma gondii, manipulates an immune cell needed for immunity to many intracellular pathogens, the CD8 T cell. Host pathways that govern CD8 T cell production of the immune protective cytokine, IFNγ, were also explored. We hypothesized the secreted T. gondii virulence factor, ROP5, work to inhibit the MHC 1 antigen presentation pathway therefore making it difficult for CD8 T cells to see T. gondii antigens sequestered inside a parasitophorous vacuole. However, manipulation through T. gondii ROP5 does not fully explain how CD8 T cells commit to making IFNγ in response to infection. Importantly, CD8 T cell IFNγ responses to T. gondii require the pathogen sensor NLRP3 to be expressed in the infected cell. Other proteins associated with NLRP3 activation, including members of the conventional inflammasome activation cascade pathway, are only partially involved. Our results identify a novel pathway by which NLRP3 regulates T cell function and underscore the need for NLRP3-activating adjuvants in vaccines aimed at inducing CD8 T cell IFNγ responses to parasites.
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Affiliation(s)
- Angel K. Kongsomboonvech
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
| | - Felipe Rodriguez
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
| | - Anh L. Diep
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
| | - Brandon M. Justice
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
| | - Brayan E. Castallanos
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
| | - Ana Camejo
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Debanjan Mukhopadhyay
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Gregory A. Taylor
- Departments of Medicine; Molecular Genetics and Microbiology; and Immunology; and Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina, United States of America
- Geriatric Research, Education, and Clinical Center, Durham VA Health Care System, Durham, North Carolina, United States of America
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Jeroen P. J. Saeij
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Michael L. Reese
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, Texas, United States of America
| | - Kirk D. C. Jensen
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
- Health Sciences Research Institute, University of California, Merced, Merced, California, United States of America
- * E-mail:
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6
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Tsitsiklis A, Bangs DJ, Robey EA. CD8+ T Cell Responses to Toxoplasma gondii: Lessons from a Successful Parasite. Trends Parasitol 2019; 35:887-898. [DOI: 10.1016/j.pt.2019.08.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/22/2019] [Accepted: 08/26/2019] [Indexed: 01/21/2023]
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Rommereim LM, Fox BA, Butler KL, Cantillana V, Taylor GA, Bzik DJ. Rhoptry and Dense Granule Secreted Effectors Regulate CD8 + T Cell Recognition of Toxoplasma gondii Infected Host Cells. Front Immunol 2019; 10:2104. [PMID: 31555296 PMCID: PMC6742963 DOI: 10.3389/fimmu.2019.02104] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 08/21/2019] [Indexed: 12/21/2022] Open
Abstract
Toxoplasma gondii secretes rhoptry (ROP) and dense granule (GRA) effector proteins to evade host immune clearance mediated by interferon gamma (IFN-γ), immunity-related GTPase (IRG) effectors, and CD8+ T cells. Here, we investigated the role of parasite-secreted effectors in regulating host access to parasitophorous vacuole (PV) localized parasite antigens and their presentation to CD8+ T cells by the major histocompatibility class I (MHC-I) pathway. Antigen presentation of PV localized parasite antigens by MHC-I was significantly increased in macrophages and/or dendritic cells infected with mutant parasites that lacked expression of secreted GRA (GRA2, GRA3, GRA4, GRA5, GRA7, GRA12) or ROP (ROP5, ROP18) effectors. The ability of various secreted GRA or ROP effectors to suppress antigen presentation by MHC-I was dependent on cell type, expression of IFN-γ, or host IRG effectors. The suppression of antigen presentation by ROP5, ROP18, and GRA7 correlated with a role for these molecules in preventing PV disruption by IFN-γ-activated host IRG effectors. However, GRA2 mediated suppression of antigen presentation was not correlated with PV disruption. In addition, the GRA2 antigen presentation phenotypes were strictly co-dependent on the expression of the GRA6 protein. These results show that MHC-I antigen presentation of PV localized parasite antigens was controlled by mechanisms that were dependent or independent of IRG effector mediated PV disruption. Our findings suggest that the GRA6 protein underpins an important mechanism that enhances CD8+ T cell recognition of parasite-infected cells with damaged or ruptured PV membranes. However, in intact PVs, parasite secreted effector proteins that associate with the PV membrane or the intravacuolar network membranes play important roles to actively suppress antigen presentation by MHC-I to reduce CD8+ T cell recognition and clearance of Toxoplasma gondii infected host cells.
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Affiliation(s)
- Leah M Rommereim
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
| | - Barbara A Fox
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
| | - Kiah L Butler
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
| | - Viviana Cantillana
- Division of Geriatrics, Departments of Medicine, Molecular Genetics and Microbiology, and Immunology, Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, NC, United States
| | - Gregory A Taylor
- Division of Geriatrics, Departments of Medicine, Molecular Genetics and Microbiology, and Immunology, Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, NC, United States.,Geriatric Research, Education and Clinical Center, VA Medical Center, Durham, NC, United States
| | - David J Bzik
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
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Poncet AF, Blanchard N, Marion S. Toxoplasma and Dendritic Cells: An Intimate Relationship That Deserves Further Scrutiny. Trends Parasitol 2019; 35:870-886. [PMID: 31492624 DOI: 10.1016/j.pt.2019.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/01/2019] [Accepted: 08/04/2019] [Indexed: 02/07/2023]
Abstract
Toxoplasma gondii (Tg), an obligate intracellular parasite of the phylum Apicomplexa, infects a wide range of animals, including humans. A hallmark of Tg infection is the subversion of host responses, which is thought to favor parasite persistence and propagation to new hosts. Recently, a variety of parasite-secreted modulatory effectors have been uncovered in fibroblasts and macrophages, but the specific interplay between Tg and dendritic cells (DCs) is just beginning to emerge. In this review, we summarize the current knowledge on Tg-DC interactions, including innate recognition, cytokine production, and antigen presentation, and discuss open questions regarding how Tg-secreted effectors may shape DC functions to perturb innate and adaptive immunity.
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Affiliation(s)
- Anaïs F Poncet
- Centre d'Infection et d'Immunité de Lille, Université de Lille, Inserm U1019, CNRS UMR 8204, CHU Lille, Institut Pasteur de Lille, Lille, France
| | - Nicolas Blanchard
- Centre de Physiopathologie Toulouse Purpan (CPTP), Université de Toulouse, INSERM, CNRS, UPS, Toulouse, France. @inserm.fr
| | - Sabrina Marion
- Centre d'Infection et d'Immunité de Lille, Université de Lille, Inserm U1019, CNRS UMR 8204, CHU Lille, Institut Pasteur de Lille, Lille, France. @pasteur-lille.fr
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9
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Melchor SJ, Ewald SE. Disease Tolerance in Toxoplasma Infection. Front Cell Infect Microbiol 2019; 9:185. [PMID: 31245299 PMCID: PMC6563770 DOI: 10.3389/fcimb.2019.00185] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 05/14/2019] [Indexed: 01/12/2023] Open
Abstract
Toxoplasma gondii is a successful protozoan parasite that cycles between definitive felid hosts and a broad range of intermediate hosts, including rodents and humans. Within intermediate hosts, this obligate intracellular parasite invades the small intestine, inducing an inflammatory response. Toxoplasma infects infiltrating immune cells, using them to spread systemically and reach tissues amenable to chronic infection. An intact immune system is necessary to control life-long chronic infection. Chronic infection is characterized by formation of parasite cysts, which are necessary for survival through the gastrointestinal tract of the next host. Thus, Toxoplasma must evade sterilizing immunity, but still rely on the host's immune response for survival and transmission. To do this, Toxoplasma exploits a central cost-benefit tradeoff in immunity: the need to escalate inflammation for pathogen clearance vs. the need to limit inflammation-induced bystander damage. What are the consequences of sustained inflammation on host biology? Many studies have focused on aspects of the immune response that directly target Toxoplasma growth and survival, commonly referred to as "resistance mechanisms." However, it is becoming clear that a parallel arm of the immune response has evolved to mitigate damage caused by the parasite directly (for example, egress-induced cell death) or bystander damage due to the inflammatory response (for example, reactive nitrogen species, degranulation). These so-called "disease tolerance" mechanisms promote tissue function and host survival without directly targeting the pathogen. Here we review changes to host metabolism, tissue structure, and immune function that point to disease tolerance mechanisms during Toxoplasma infection. We explore the impact tolerance programs have on the health of the host and parasite biology.
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Affiliation(s)
| | - Sarah E. Ewald
- Department of Microbiology, Immunology and Cancer Biology and the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, VA, United States
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10
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Hatter JA, Kouche YM, Melchor SJ, Ng K, Bouley DM, Boothroyd JC, Ewald SE. Toxoplasma gondii infection triggers chronic cachexia and sustained commensal dysbiosis in mice. PLoS One 2018; 13:e0204895. [PMID: 30379866 PMCID: PMC6209157 DOI: 10.1371/journal.pone.0204895] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 09/13/2018] [Indexed: 01/14/2023] Open
Abstract
Toxoplasma gondii is a protozoan parasite with a predation-mediated transmission cycle between rodents and felines. Intermediate hosts acquire Toxoplasma by eating parasite cysts which invade the small intestine, disseminate systemically and finally establish host life-long chronic infection in brain and muscles. Here we show that Toxoplasma infection can trigger a severe form of sustained cachexia: a disease of progressive lean weight loss that is a causal predictor of mortality in cancer, chronic disease and many infections. Toxoplasma cachexia is characterized by acute anorexia, systemic inflammation and loss of 20% body mass. Although mice recover from symptoms of peak sickness, they fail to regain muscle mass or visceral adipose depots. We asked whether the damage to the intestinal microenvironment observed at acute time points was sustained in chronic infection and could thereby play a role in sustaining cachexia. We found that parasites replicate in the same region of the distal jejunum/proximal ileum throughout acute infection, inducing the development of secondary lymphoid structures and severe, regional inflammation. Small intestine pathology was resolved by 5 weeks post-infection. However, changes in the commensal populations, notably an outgrowth of Clostridia spp., were sustained in chronic infection. Importantly, uninfected animals co-housed with infected mice display similar changes in commensal microflora but never display symptoms of cachexia, indicating that altered commensals are not sufficient to explain the cachexia phenotype alone. These studies indicate that Toxoplasma infection is a novel and robust model to study the immune-metabolic interactions that contribute to chronic cachexia development, pathology and potential reversal.
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Affiliation(s)
- Jessica A. Hatter
- Department of Microbiology, Immunology and Cancer Biology and the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, VA, United States of America
| | - Yue Moi Kouche
- Department of Comparative Medicine, Stanford University, Stanford CA, United States of America
| | - Stephanie J. Melchor
- Department of Microbiology, Immunology and Cancer Biology and the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, VA, United States of America
| | - Katherine Ng
- Department of Microbiology and Immunology, Stanford University, Stanford CA, United States of America
| | - Donna M. Bouley
- Department of Comparative Medicine, Stanford University, Stanford CA, United States of America
| | - John C. Boothroyd
- Department of Microbiology and Immunology, Stanford University, Stanford CA, United States of America
| | - Sarah E. Ewald
- Department of Microbiology, Immunology and Cancer Biology and the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, VA, United States of America
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11
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Buaillon C, Guerrero NA, Cebrian I, Blanié S, Lopez J, Bassot E, Vasseur V, Santi-Rocca J, Blanchard N. MHC I presentation of Toxoplasma gondii immunodominant antigen does not require Sec22b and is regulated by antigen orientation at the vacuole membrane. Eur J Immunol 2017; 47:1160-1170. [PMID: 28508576 DOI: 10.1002/eji.201646859] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 03/21/2017] [Accepted: 05/09/2017] [Indexed: 12/16/2022]
Abstract
The intracellular Toxoplasma gondii parasite replicates within a parasitophorous vacuole (PV). T. gondii secretes proteins that remain soluble in the PV space, are inserted into PV membranes or are exported beyond the PV boundary. In addition to supporting T. gondii growth, these proteins can be processed and presented by MHC I for CD8+ T-cell recognition. Yet it is unclear whether membrane binding influences the processing pathways employed and if topology of membrane antigens impacts their MHC I presentation. Here we report that the MHC I pathways of soluble and membrane-bound antigens differ in their requirement for host ER recruitment. In contrast to the soluble SAG1-OVA model antigen, we find that presentation of the membrane-bound GRA6 is independent from the SNARE Sec22b, a key molecule for transfer of host endoplasmic reticulum components onto the PV. Using parasites modified to secrete a transmembrane antigen with opposite orientations, we further show that MHC I presentation is highly favored when the C-terminal epitope is exposed to the host cell cytosol, which corresponds to GRA6 natural orientation. Our data suggest that the biochemical properties of antigens released by intracellular pathogens critically guide their processing pathway and are valuable parameters to consider for vaccination strategies.
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Affiliation(s)
- Célia Buaillon
- Centre de Physiopathologie Toulouse Purpan (CPTP), INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Nestor A Guerrero
- Centre de Physiopathologie Toulouse Purpan (CPTP), INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Ignacio Cebrian
- Instituto de Histología y Embriología de Mendoza (IHEM)-CONICET/UNCuyo, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Sophie Blanié
- Centre de Physiopathologie Toulouse Purpan (CPTP), INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Jodie Lopez
- Centre de Physiopathologie Toulouse Purpan (CPTP), INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Emilie Bassot
- Centre de Physiopathologie Toulouse Purpan (CPTP), INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Virginie Vasseur
- Centre de Physiopathologie Toulouse Purpan (CPTP), INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Julien Santi-Rocca
- Centre de Physiopathologie Toulouse Purpan (CPTP), INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Nicolas Blanchard
- Centre de Physiopathologie Toulouse Purpan (CPTP), INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
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12
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Chu HH, Chan SW, Gosling JP, Blanchard N, Tsitsiklis A, Lythe G, Shastri N, Molina-París C, Robey EA. Continuous Effector CD8(+) T Cell Production in a Controlled Persistent Infection Is Sustained by a Proliferative Intermediate Population. Immunity 2016; 45:159-71. [PMID: 27421704 DOI: 10.1016/j.immuni.2016.06.013] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 03/31/2016] [Accepted: 04/20/2016] [Indexed: 01/22/2023]
Abstract
Highly functional CD8(+) effector T (Teff) cells can persist in large numbers during controlled persistent infections, as exemplified by rare HIV-infected individuals who control the virus. Here we examined the cellular mechanisms that maintain ongoing T effector responses using a mouse model for persistent Toxoplasma gondii infection. In mice expressing the protective MHC-I molecule, H-2L(d), a dominant T effector response against a single parasite antigen was maintained without a contraction phase, correlating with ongoing presentation of the dominant antigen. Large numbers of short-lived Teff cells were continuously produced via a proliferative, antigen-dependent intermediate (Tint) population with a memory-effector hybrid phenotype. During an acute, resolved infection, decreasing antigen load correlated with a sharp drop in the Tint cell population and subsequent loss of the ongoing effector response. Vaccination approaches aimed at the development of Tint populations might prove effective against pathogens that lead to chronic infection.
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Affiliation(s)
- H Hamlet Chu
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA.
| | - Shiao-Wei Chan
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - John Paul Gosling
- Departments of Statistics, School of Mathematics, University of Leeds, Leeds LS2 9JT, UK
| | - Nicolas Blanchard
- Center of Pathophysiology of Toulouse-Purpan, INSERM UMR1043-CNRS UMR5282, University of Toulouse, 31024 Toulouse Cedex 3, France
| | - Alexandra Tsitsiklis
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Grant Lythe
- Applied Mathematics, School of Mathematics, University of Leeds, Leeds LS2 9JT, UK
| | - Nilabh Shastri
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Carmen Molina-París
- Applied Mathematics, School of Mathematics, University of Leeds, Leeds LS2 9JT, UK
| | - Ellen A Robey
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA.
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13
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McMurtrey C, Trolle T, Sansom T, Remesh SG, Kaever T, Bardet W, Jackson K, McLeod R, Sette A, Nielsen M, Zajonc DM, Blader IJ, Peters B, Hildebrand W. Toxoplasma gondii peptide ligands open the gate of the HLA class I binding groove. eLife 2016; 5. [PMID: 26824387 PMCID: PMC4775218 DOI: 10.7554/elife.12556] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/28/2016] [Indexed: 01/10/2023] Open
Abstract
HLA class I presentation of pathogen-derived peptide ligands is essential for CD8+ T-cell recognition of Toxoplasma gondii infected cells. Currently, little data exist pertaining to peptides that are presented after T. gondii infection. Herein we purify HLA-A*02:01 complexes from T. gondii infected cells and characterize the peptide ligands using LCMS. We identify 195 T. gondii encoded ligands originating from both secreted and cytoplasmic proteins. Surprisingly, T. gondii ligands are significantly longer than uninfected host ligands, and these longer pathogen-derived peptides maintain a canonical N-terminal binding core yet exhibit a C-terminal extension of 1–30 amino acids. Structural analysis demonstrates that binding of extended peptides opens the HLA class I F’ pocket, allowing the C-terminal extension to protrude through one end of the binding groove. In summary, we demonstrate that unrealized structural flexibility makes MHC class I receptive to parasite-derived ligands that exhibit unique C-terminal peptide extensions. DOI:http://dx.doi.org/10.7554/eLife.12556.001 Toxoplasma gondii is a parasite that can infect most warm-blooded animals and cause a disease called toxoplasmosis. In humans, toxoplasmosis generally does not cause any noticeable symptoms, but it can cause serious problems in pregnant women and individuals with weakened immune systems. T. gondii is one of many parasites that hide within human cells in an attempt to avoid detection by the immune system. However, proteins called Human Leukocyte Antigens, or HLAs, can reveal hidden parasites by carrying small sections of them from the inside the infected cell to the cell’s surface. The immune system can then recognize the fragments as foreign and attack the parasite. HLAs typically pick up parasite fragments of a certain length, which enables the immune system to recognize that what is being displayed is a piece of parasite. By purifying HLAs from cells that have been infected by T. gondii, McMurtrey et al. have now learned more about which fragments of the parasite are displayed to the immune system. This analysis revealed that the parasite somehow manipulates the HLAs to carry parasite fragments that are considerably longer than can be explained with our current knowledge of how HLAs work. By using a technique called X-ray crystallography, McMurtrey et al. also show that the structure of the HLA assumes a previously unseen configuration when interacting with fragments of T. gondii. In the future, it will be important to understand how infected cells give rise to unusual structural configurations of HLAs and to unravel how these structures affect the immune system’s ability to fight infections. DOI:http://dx.doi.org/10.7554/eLife.12556.002
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Affiliation(s)
- Curtis McMurtrey
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, United States.,Pure MHC LLC, Austin, United States
| | - Thomas Trolle
- Center for Biological Sequence Analysis, Technical University of Denmark, Kongens Lyngby, Denmark.,La Jolla Institute for Allergy and Immunology, La Jolla, United States
| | - Tiffany Sansom
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, United States
| | - Soumya G Remesh
- La Jolla Institute for Allergy and Immunology, La Jolla, United States
| | - Thomas Kaever
- La Jolla Institute for Allergy and Immunology, La Jolla, United States
| | - Wilfried Bardet
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, United States
| | - Kenneth Jackson
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, United States
| | - Rima McLeod
- University of Chicago, Chicago, United States
| | - Alessandro Sette
- La Jolla Institute for Allergy and Immunology, La Jolla, United States
| | - Morten Nielsen
- Center for Biological Sequence Analysis, Technical University of Denmark, Kongens Lyngby, Denmark.,Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Dirk M Zajonc
- La Jolla Institute for Allergy and Immunology, La Jolla, United States
| | - Ira J Blader
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, United States
| | - Bjoern Peters
- La Jolla Institute for Allergy and Immunology, La Jolla, United States
| | - William Hildebrand
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, United States.,Pure MHC LLC, Austin, United States
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14
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Zorgi NE, Galisteo AJ, Sato MN, do Nascimento N, de Andrade HF. Immunity in the spleen and blood of mice immunized with irradiated Toxoplasma gondii tachyzoites. Med Microbiol Immunol 2016; 205:297-314. [PMID: 26732075 DOI: 10.1007/s00430-015-0447-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 12/21/2015] [Indexed: 01/14/2023]
Abstract
Toxoplasma gondii infection induces a strong and long-lasting immune response that is able to prevent most reinfections but allows tissue cysts. Irradiated, sterilized T. gondii tachyzoites are an interesting vaccine, and they induce immunity that is similar to infection, but without cysts. In this study, we evaluated the cellular immune response in the blood and spleen of mice immunized with this preparation by mouth (v.o.) or intraperitoneally (i.p.) and analyzed the protection after challenge with viable parasites. BALB/c mice were immunized with three i.p. or v.o. doses of irradiated T. gondii tachyzoites. Oral challenge with ten cysts of the ME-49 or VEG strain at 90 days after the last dose resulted in high levels of protection with low parasite burden in the immunized animals. There were higher levels of specific IgG, IgA and IgM antibodies in the serum, and the i.p. immunized mice had higher levels of the high-affinity IgG and IgM antibodies than the orally immunized mice, which had more high-affinity IgA antibodies. B cells (CD19(+)), plasma cells (CD138(+)) and the CD4(+) and CD8(+) T cell populations were increased in both the blood and spleen. Cells from the spleen of the i.p. immunized mice also showed antigen-induced production of interleukin-10 (IL-10), interferon gamma (IFN-γ) and interleukin 4 (IL-4). The CD4(+) T cells, B cells and likely CD8(+) T cells from the spleens of the i.p. immunized mice proliferated with a specific antigen. The protection was correlated with the spleen and blood CD8(+) T cell, high-affinity IgG and IgM and antigen-induced IL-10 and IL-4 production. Immunization with irradiated T. gondii tachyzoites induces an immune response that is mediated by B cells and CD4(+) and CD8(+) T cells, with increased humoral and cellular immune responses that are necessary for host protection after infection. The vaccine is similar to natural infection, but free of tissue cysts; this immunity restrains infection at challenge and can be an attractive and efficient model for vaccine development in toxoplasmosis.
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MESH Headings
- Administration, Oral
- Animals
- Antibodies, Protozoan/blood
- B-Lymphocytes/immunology
- Blood/immunology
- Cell Proliferation
- Cytokines/metabolism
- Disease Models, Animal
- Immunity, Cellular
- Immunity, Humoral
- Immunoglobulin A/blood
- Immunoglobulin G/blood
- Immunoglobulin M/blood
- Injections, Intraperitoneal
- Male
- Mice, Inbred BALB C
- Protozoan Vaccines/administration & dosage
- Protozoan Vaccines/immunology
- Spleen/immunology
- T-Lymphocyte Subsets/immunology
- Toxoplasma/immunology
- Toxoplasmosis, Animal/prevention & control
- Vaccines, Inactivated/administration & dosage
- Vaccines, Inactivated/immunology
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Affiliation(s)
- Nahiara Esteves Zorgi
- Departamento de Parasitologia, Instituto de Ciências Biomédica, USP, Av. Prof. Lineu Prestes, 1374, Edifício Biomédicas II Cidade Universitária, São Paulo, SP, CEP: 05508-000, Brazil
- Laboratório de Protozoologia, Instituto de Medicina Tropical de São Paulo, FMUSP, USP, Av. Dr. Enéas de Carvalho Aguiar, 470, 1° Andar, São Paulo, SP, CEP: 05403-000, Brazil
| | - Andrés Jimenez Galisteo
- Laboratório de Protozoologia, Instituto de Medicina Tropical de São Paulo, FMUSP, USP, Av. Dr. Enéas de Carvalho Aguiar, 470, 1° Andar, São Paulo, SP, CEP: 05403-000, Brazil
| | - Maria Notomi Sato
- Departamento de Dermatologia, Instituto de Medicina Tropical de São Paulo, FMUSP, USP, Av. Dr. Enéas de Carvalho Aguiar, 470, 3° Andar, São Paulo, SP, CEP: 05403-000, Brazil
| | - Nanci do Nascimento
- Laboratório de Biologia Molecular, Instituto de Pesquisas Energéticas e Nucleares, IPEN, Rua Travessa 400, Cidade Universitária, São Paulo, SP, CEP: 05508-900, Brazil
| | - Heitor Franco de Andrade
- Departamento de Parasitologia, Instituto de Ciências Biomédica, USP, Av. Prof. Lineu Prestes, 1374, Edifício Biomédicas II Cidade Universitária, São Paulo, SP, CEP: 05508-000, Brazil.
- Laboratório de Protozoologia, Instituto de Medicina Tropical de São Paulo, FMUSP, USP, Av. Dr. Enéas de Carvalho Aguiar, 470, 1° Andar, São Paulo, SP, CEP: 05403-000, Brazil.
- Department of Pathology, Faculty of Medicine, Universidade de São Paulo, São Paulo, Brazil.
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15
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Jensen KDC. Antigen Presentation of Vacuolated Apicomplexans--Two Gateways to a Vaccine Antigen. Trends Parasitol 2015; 32:88-90. [PMID: 26733404 DOI: 10.1016/j.pt.2015.12.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 12/16/2015] [Indexed: 12/11/2022]
Abstract
For parasites that sequester themselves within a vacuole, new rules governing antigen presentation are coming into focus. Components of the host's autophagy machinery and the parasite's membranous nanotubular network within the parasitophorous vacuole play a major role in determining antigenicity of Toxoplasma proteins. As such, both parasite and vaccinologist may exploit these pathways to regulate the ever important CD8 T cell response to apicomplexan parasites.
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Affiliation(s)
- Kirk D C Jensen
- School of Natural Sciences, University of California, Merced, 5200 North Lake Road, Merced, CA 95343, USA.
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16
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Lopez J, Bittame A, Massera C, Vasseur V, Effantin G, Valat A, Buaillon C, Allart S, Fox BA, Rommereim LM, Bzik DJ, Schoehn G, Weissenhorn W, Dubremetz JF, Gagnon J, Mercier C, Cesbron-Delauw MF, Blanchard N. Intravacuolar Membranes Regulate CD8 T Cell Recognition of Membrane-Bound Toxoplasma gondii Protective Antigen. Cell Rep 2015; 13:2273-86. [PMID: 26628378 DOI: 10.1016/j.celrep.2015.11.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 08/11/2015] [Accepted: 10/30/2015] [Indexed: 11/20/2022] Open
Abstract
Apicomplexa parasites such as Toxoplasma gondii target effectors to and across the boundary of their parasitophorous vacuole (PV), resulting in host cell subversion and potential presentation by MHC class I molecules for CD8 T cell recognition. The host-parasite interface comprises the PV limiting membrane and a highly curved, membranous intravacuolar network (IVN) of uncertain function. Here, using a cell-free minimal system, we dissect how membrane tubules are shaped by the parasite effectors GRA2 and GRA6. We show that membrane association regulates access of the GRA6 protective antigen to the MHC I pathway in infected cells. Although insertion of GRA6 in the PV membrane is key for immunogenicity, association of GRA6 with the IVN limits presentation and curtails GRA6-specific CD8 responses in mice. Thus, membrane deformations of the PV regulate access of antigens to the MHC class I pathway, and the IVN may play a role in immune modulation.
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Affiliation(s)
- Jodie Lopez
- INSERM, U1043, Toulouse 31300, France; CNRS, UMR 5282, Toulouse 31300, France; Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UPS, Toulouse 31300, France
| | - Amina Bittame
- CNRS, UMR 5163, Grenoble 38000, France; Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), Université Grenoble Alpes, Grenoble 38000, France
| | - Céline Massera
- CNRS, UMR 5163, Grenoble 38000, France; Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), Université Grenoble Alpes, Grenoble 38000, France
| | - Virginie Vasseur
- INSERM, U1043, Toulouse 31300, France; CNRS, UMR 5282, Toulouse 31300, France; Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UPS, Toulouse 31300, France
| | - Grégory Effantin
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, Grenoble 38044, France; CNRS, IBS, Grenoble 38044, France; CEA, IBS, Grenoble 38044, France; CNRS, Unit for Virus Host-Cell Interactions (UVHCI), Grenoble 38042, France
| | - Anne Valat
- CNRS, UMR 5163, Grenoble 38000, France; Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), Université Grenoble Alpes, Grenoble 38000, France
| | - Célia Buaillon
- INSERM, U1043, Toulouse 31300, France; CNRS, UMR 5282, Toulouse 31300, France; Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UPS, Toulouse 31300, France
| | - Sophie Allart
- INSERM, U1043, Toulouse 31300, France; CNRS, UMR 5282, Toulouse 31300, France; Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UPS, Toulouse 31300, France
| | - Barbara A Fox
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA
| | - Leah M Rommereim
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA
| | - David J Bzik
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA
| | - Guy Schoehn
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, Grenoble 38044, France; CNRS, IBS, Grenoble 38044, France; CEA, IBS, Grenoble 38044, France; CNRS, Unit for Virus Host-Cell Interactions (UVHCI), Grenoble 38042, France
| | - Winfried Weissenhorn
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, Grenoble 38044, France; CNRS, IBS, Grenoble 38044, France; CEA, IBS, Grenoble 38044, France; CNRS, Unit for Virus Host-Cell Interactions (UVHCI), Grenoble 38042, France
| | | | - Jean Gagnon
- CNRS, UMR 5163, Grenoble 38000, France; Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), Université Grenoble Alpes, Grenoble 38000, France
| | - Corinne Mercier
- CNRS, UMR 5163, Grenoble 38000, France; Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), Université Grenoble Alpes, Grenoble 38000, France
| | - Marie-France Cesbron-Delauw
- CNRS, UMR 5163, Grenoble 38000, France; Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), Université Grenoble Alpes, Grenoble 38000, France
| | - Nicolas Blanchard
- INSERM, U1043, Toulouse 31300, France; CNRS, UMR 5282, Toulouse 31300, France; Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UPS, Toulouse 31300, France.
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17
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Review on the identification and role of Toxoplasma gondii antigenic epitopes. Parasitol Res 2015; 115:459-68. [PMID: 26581372 DOI: 10.1007/s00436-015-4824-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 11/10/2015] [Indexed: 12/12/2022]
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite with a broad range of hosts, and it causes severe toxoplasmasis in both humans and animals. It is well known that the progression and severity of a disease depend on the immunological status of the host. Immunological studies on antigens indicate that antigens do not exert their functions through the entire protein molecule, but instead, specific epitopes are responsible for the immune response. Protein antigens not only contain epitope structures used by B, T, cytotoxic T lymphocyte (CTL), and NK cells to mediate immunological responses but can also contain structures that are unfavorable for protective immunity. Therefore, the study of antigenic epitopes from T. gondii has not only enhanced our understanding of the structure and function of antigens, the reactions between antigens and antibodies, and many other aspects of immunology but it also plays a significant role in the development of new diagnostic reagents and vaccines. In this review, we summarized the immune mechanisms induced by antigen epitopes and the latest advances in identifying T. gondii antigen epitopes. Particular attention was paid to the potential clinical usefulness of epitopes in this context. Through a critical analysis of the current state of knowledge, we elucidated the latest data concerning the biological effects of epitopes and the immune results aimed at the development of future epitope-based applications, such as vaccines and diagnostic reagents.
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18
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Lee Y, Sasai M, Ma JS, Sakaguchi N, Ohshima J, Bando H, Saitoh T, Akira S, Yamamoto M. p62 Plays a Specific Role in Interferon-γ-Induced Presentation of a Toxoplasma Vacuolar Antigen. Cell Rep 2015; 13:223-33. [PMID: 26440898 DOI: 10.1016/j.celrep.2015.09.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 08/04/2015] [Accepted: 08/31/2015] [Indexed: 12/11/2022] Open
Abstract
Also known as Sqstm1, p62 is a selective autophagy adaptor with a ubiquitin-binding domain. However, the role of p62 in the host defense against Toxoplasma gondii infection is unclear. Here, we show that interferon γ (IFN-γ) stimulates ubiquitin and p62 recruitment to T. gondii parasitophorous vacuoles (PVs). Some essential autophagy-related proteins, but not all, are required for this recruitment. Regardless of normal IFN-γ-induced T. gondii clearance activity and ubiquitination, p62 deficiency in antigen-presenting cells (APCs) and mice diminishes the robust IFN-γ-primed activation of CD8(+) T cells that recognize the T. gondii-derived antigen secreted into PVs. Because the expression of Atg3 and Irgm1/m3 in APCs is essential for PV disruption, ubiquitin and p62 recruitment, and vacuolar-antigen-specific CD8(+) T cell activation, IFN-γ-mediated ubiquitination and the subsequent recruitment of p62 to T. gondii are specifically required for the acquired immune response after PV disruption by IFN-γ-inducible GTPases.
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Affiliation(s)
- Youngae Lee
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan; Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Miwa Sasai
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan; Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Ji Su Ma
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan; Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Naoya Sakaguchi
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan; Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Jun Ohshima
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan; Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Hironori Bando
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan; Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Tatsuya Saitoh
- Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan; Laboratory of Host Defense, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan; Division of Molecular Genetics, Institute for Enzyme Research, Tokushima University, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | - Shizuo Akira
- Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan; Laboratory of Host Defense, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan; Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
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Blanchard N, Dunay IR, Schlüter D. Persistence of Toxoplasma gondii in the central nervous system: a fine-tuned balance between the parasite, the brain and the immune system. Parasite Immunol 2015; 37:150-8. [PMID: 25573476 DOI: 10.1111/pim.12173] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 12/30/2014] [Indexed: 02/04/2023]
Abstract
Upon infection of humans and animals with Toxoplasma gondii, the parasites persist as intraneuronal cysts that are controlled, but not eliminated by the immune system. In particular, intracerebral T cells are crucial in the control of T. gondii infection and are supported by essential functions from other leukocyte populations. Additionally, brain-resident cells including astrocytes, microglia and neurons contribute to the intracerebral immune response by the production of cytokines, chemokines and expression of immunoregulatory cell surface molecules, such as major histocompatibility (MHC) antigens. However, the in vivo behaviour of these individual cell populations, specifically their interaction during cerebral toxoplasmosis, remains to be elucidated. We discuss here what is known about the function of T cells, recruited myeloid cells and brain-resident cells, with particular emphasis on the potential cross-regulation of these cell populations, in governing cerebral toxoplasmosis.
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Affiliation(s)
- N Blanchard
- Inserm U1043, Toulouse, France; CNRS U5282, Toulouse, France; Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UPS, Toulouse, France
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Toxoplasma gondii superinfection and virulence during secondary infection correlate with the exact ROP5/ROP18 allelic combination. mBio 2015; 6:e02280. [PMID: 25714710 PMCID: PMC4358003 DOI: 10.1128/mbio.02280-14] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intracellular parasite Toxoplasma gondii infects a wide variety of vertebrate species globally. Infection in most hosts causes a lifelong chronic infection and generates immunological memory responses that protect the host against new infections. In regions where the organism is endemic, multiple exposures to T. gondii likely occur with great frequency, yet little is known about the interaction between a chronically infected host and the parasite strains from these areas. A widely used model to explore secondary infection entails challenge of chronically infected or vaccinated mice with the highly virulent type I RH strain. Here, we show that although vaccinated or chronically infected C57BL/6 mice are protected against the type I RH strain, they are not protected against challenge with most strains prevalent in South America or another type I strain, GT1. Genetic and genomic analyses implicated the parasite-secreted rhoptry effectors ROP5 and ROP18, which antagonize the host’s gamma interferon-induced immunity-regulated GTPases (IRGs), as primary requirements for virulence during secondary infection. ROP5 and ROP18 promoted parasite superinfection in the brains of challenged survivors. We hypothesize that superinfection may be an important mechanism to generate T. gondii strain diversity, simply because two parasite strains would be present in a single meal consumed by the feline definitive host. Superinfection may drive the genetic diversity of Toxoplasma strains in South America, where most isolates are IRG resistant, compared to North America, where most strains are IRG susceptible and are derived from a few clonal lineages. In summary, ROP5 and ROP18 promote Toxoplasma virulence during reinfection. Toxoplasma gondii is a widespread parasite of warm-blooded animals and currently infects one-third of the human population. A long-standing assumption in the field is that prior exposure to this parasite protects the host from subsequent reexposure, due to the generation of protective immunological memory. However, this assumption is based on clinical data and mouse models that analyze infections with strains common to Europe and North America. In contrast, we found that the majority of strains sampled from around the world, in particular those from South America, were able to kill or reinfect the brains of hosts previously exposed to T. gondii. The T. gondii virulence factors ROP5 and ROP18, which inhibit key host effectors that mediate parasite killing, were required for these phenotypes. We speculate that these results underpin clinical observations that pregnant women previously exposed to Toxoplasma can develop congenital infection upon reexposure to South American strains.
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Mercier C, Cesbron-Delauw MF. Toxoplasma secretory granules: one population or more? Trends Parasitol 2015; 31:60-71. [PMID: 25599584 DOI: 10.1016/j.pt.2014.12.002] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 12/10/2014] [Accepted: 12/10/2014] [Indexed: 01/20/2023]
Abstract
In Toxoplasma gondii, dense granules are known as the storage secretory organelles of the so-called GRA proteins (for dense granule proteins), which are destined to the parasitophorous vacuole (PV) and the PV-derived cyst wall. Recently, newly annotated GRA proteins targeted to the host cell nucleus have enlarged this view. Here we provide an update on the latest developments on the Toxoplasma secreted proteins, which to date have been mainly studied at both the tachyzoite and bradyzoite stages, and we point out that recent discoveries could open the issue of a possible, yet uncharacterized, distinct secretory pathway in Toxoplasma.
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Affiliation(s)
- Corinne Mercier
- Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), CNRS UMR 5163 - Université Joseph Fourier, Grenoble, France.
| | - Marie-France Cesbron-Delauw
- Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), CNRS UMR 5163 - Université Joseph Fourier, Grenoble, France.
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