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Kulkarni R, Kasani SK, Tsai CY, Tung SY, Yeh KH, Yu CHA, Chang W. FAM21 is critical for TLR2/CLEC4E-mediated dendritic cell function against Candida albicans. Life Sci Alliance 2023; 6:e202201414. [PMID: 36717248 PMCID: PMC9888482 DOI: 10.26508/lsa.202201414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/31/2023] Open
Abstract
FAM21 (family with sequence similarity 21) is a component of the Wiskott-Aldrich syndrome protein and SCAR homologue (WASH) protein complex that mediates actin polymerization at endosomal membranes to facilitate sorting of cargo-containing vesicles out of endosomes. To study the function of FAM21 in vivo, we generated conditional knockout (cKO) mice in the C57BL/6 background in which FAM21 was specifically knocked out of CD11c-positive dendritic cells. BMDCs from those mice displayed enlarged early endosomes, and altered cell migration and morphology relative to WT cells. FAM21-cKO cells were less competent in phagocytosis and protein antigen presentation in vitro, though peptide antigen presentation was not affected. More importantly, we identified the TLR2/CLEC4E signaling pathway as being down-regulated in FAM21-cKO BMDCs when challenged with its specific ligand Candida albicans Moreover, FAM21-cKO mice were more susceptible to C. albicans infection than WT mice. Reconstitution of WT BMDCs in FAM21-cKO mice rescued them from lethal C. albicans infection. Thus, our study highlights the importance of FAM21 in a host immune response against a significant pathogen.
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Affiliation(s)
- Rakesh Kulkarni
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Science, National Defense Medical Center, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Siti Khadijah Kasani
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Science, National Defense Medical Center, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Ching-Yen Tsai
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Shu-Yun Tung
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Kun-Hai Yeh
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | | | - Wen Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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2
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Characterization of the HHV-6B U20 Immunoevasin. J Virol 2023; 97:e0189022. [PMID: 36688652 PMCID: PMC9973003 DOI: 10.1128/jvi.01890-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Roseoloviruses (human herpesvirus 6A [HHV-6A], -6B, and -7) infect >90% of the human population during early childhood and are thought to remain latent or persistent throughout the life of the host. As such, these viruses are among the most pervasive and stealthy of all viruses; they must necessarily excel at escaping immune detection throughout the life of the host, and yet, very little is known about how these viruses so successfully escape host defenses. Here, we characterize the expression, trafficking, and posttranslational modifications of the HHV6B U20 gene product, which is encoded within a block of genes unique to the roseoloviruses. HHV-6B U20 trafficked slowly through the secretory system, receiving several posttranslational modifications to its N-linked glycans, indicative of surface-expressed glycoproteins, and eventually reaching the cell surface before being internalized. Interestingly, U20 is also phosphorylated on at least one Ser, Thr, or Tyr residue. These results provide a framework to understand the role(s) of U20 in evading host defenses. IMPORTANCE The roseolovirus U20 proteins are virus-encoded integral membrane glycoproteins possessing class I major histocompatibility complex (MHC)-like folds. Surprisingly, although U20 proteins from HHV-6A and -6B share 92% identity, recent studies ascribe different functions to HHV6A U20 and HHV6B U20. HHV6A U20 was shown to downregulate NKG2D ligands, while HHV6B U20 was shown to inhibit tumor necrosis factor alpha (TNF-α)-induced apoptosis during nonproductive infection with HHV6B (E. Kofod-Olsen, K. Ross-Hansen, M. H. Schleimann, D. K. Jensen, et al., J Virol 86:11483-11492, 2012, https://doi.org/10.1128/jvi.00847-12; A. E. Chaouat, B. Seliger, O. Mandelboim, D. Schmiedel, Front Immunol 12:714799, 2021, https://doi.org/10.3389/fimmu.2021.714799). Here, we have performed cell biological and biochemical characterization of the trafficking, glycosylation, and posttranslational modifications occurring on HHV6B U20.
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Studying the Interactions of U24 from HHV-6 in Order to Further Elucidate Its Potential Role in MS. Viruses 2022; 14:v14112384. [PMID: 36366483 PMCID: PMC9696605 DOI: 10.3390/v14112384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/27/2022] [Accepted: 10/27/2022] [Indexed: 01/31/2023] Open
Abstract
A number of studies have suggested that human herpesvirus 6A (HHV-6A) may play a role in multiple sclerosis (MS). Three possible hypotheses have been investigated: (1) U24 from HHV-6A (U24-6A) mimics myelin basic protein (MBP) through analogous phosphorylation and interaction with Fyn-SH3; (2) U24-6A affects endocytic recycling by binding human neural precursor cell (NPC) expressed developmentally down-regulated protein 4-like WW3* domain (hNedd4L-WW3*); and (3) MS patients who express Killer Cell Immunoglobulin Like Receptor 2DL2 (KIR2DL2) on natural killer (NK) cells are more susceptible to HHV-6 infection. In this contribution, we examined the validity of these propositions by investigating the interactions of U24 from HHV-6B (U24-6B), a variant less commonly linked to MS, with Fyn-SH3 and hNedd4L-WW3* using heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) titrations and isothermal titration calorimetry (ITC). In addition, the importance of phosphorylation and the specific role of U24 in NK cell activation in MS patients were examined. Overall, the findings allowed us to shed light into the models linking HHV-6 to MS and the involvement of U24.
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Hamisu TM, Aliyu HB, Tan SW, Hair-Bejo M, Omar AR, Ideris A. Expression Profiles of Immune-Related Genes and Apoptosis Study of Avian Intraepithelial-Natural Killer Cells in Chickens Inoculated with Vaccine Strain of Newcastle Disease Virus (NDV) and Challenged with Virulent NDV. Avian Dis 2022; 66. [PMID: 36198006 DOI: 10.1637/aviandiseases-d-22-00029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 06/27/2022] [Indexed: 11/05/2022]
Abstract
In spite of the available information on the role of natural killer (NK) cells in several viral infections, the interactions between chicken intraepithelial-NK (IEL-NK) cells and Newcastle disease virus (NDV) are poorly understood. In this study, we investigated these interactions following the inoculation of chickens with NDV vaccine strain LaSota and subsequent challenge with velogenic NDV (vNDV) genotype VII (GVII) and VIII (GVIII), through quantification of IEL-NK cell's apoptosis and expression profiling of its surface receptors. Specific-pathogen-free chickens were randomly divided into six groups, as follows: one group of an uninfected control, one group infected with NDV LaSota, two groups each infected with either GVII or GVIII, and two groups inoculated with NDV LaSota and challenged with either GVII (LaSota-genotype VII [LSGVII]) or GVIII (LaSota-genotype VIII [LSGVIII]). Avian intraepithelial lymphocytes (IEL) were isolated from the duodenal loops, and CD3- cells were characterized. Immunophenotyping and apoptosis analysis of CD3-/CD25+/CD45+IEL NK cells were conducted using a flow cytometer. In addition, a gene expression study was conducted using real-time quantitative PCR. Data were analyzed using two-way analysis of variance. The results showed that vNDV GVII or GVIII caused apoptosis of IEL-NK cells; however, following inoculation of LSGVII or LSGVIII, the effect of vNDV GVII and GVIII to cause a reduction in the population of viable IEL-NK cells was significantly reduced. Furthermore, the expression profiles of activating receptors CD69, NK-lysin, and IFN-γ, were generally upregulated in chickens inoculated with LSGVII or LSGVIII. In contrast, B-NK, an inhibitory receptor, was downregulated in these treatment groups. In NDV GVII- and GVIII-challenged groups, however, B-NK was upregulated, whereas the other receptors were generally downregulated. The findings of this study showed that NDV vaccine strain LaSota may prevent apoptosis and cause upregulation of activating receptors of chicken IEL-NK cells in velogenic virus-challenged settings.
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Affiliation(s)
- Tasiu Mallam Hamisu
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Maiduguri, Maiduguri, Borno State, Nigeria
| | - Hayatuddeen Bako Aliyu
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Avian Unit, Veterinary Teaching Hospital, Ahmadu Bello University, Zaria, Nigeria
| | - Sheau Wei Tan
- Laboratory of Vaccine and Biomolecules, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Mohd Hair-Bejo
- Laboratory of Vaccine and Biomolecules, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Abdul Rahman Omar
- Laboratory of Vaccine and Biomolecules, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Aini Ideris
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor, Malaysia,
- Laboratory of Vaccine and Biomolecules, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
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5
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Weaver GC, Arya R, Schneider CL, Hudson AW, Stern LJ. Structural Models for Roseolovirus U20 And U21: Non-Classical MHC-I Like Proteins From HHV-6A, HHV-6B, and HHV-7. Front Immunol 2022; 13:864898. [PMID: 35444636 PMCID: PMC9013968 DOI: 10.3389/fimmu.2022.864898] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 03/08/2022] [Indexed: 01/08/2023] Open
Abstract
Human roseolovirus U20 and U21 are type I membrane glycoproteins that have been implicated in immune evasion by interfering with recognition of classical and non-classical MHC proteins. U20 and U21 are predicted to be type I glycoproteins with extracytosolic immunoglobulin-like domains, but detailed structural information is lacking. AlphaFold and RoseTTAfold are next generation machine-learning-based prediction engines that recently have revolutionized the field of computational three-dimensional protein structure prediction. Here, we review the structural biology of viral immunoevasins and the current status of computational structure prediction algorithms. We use these computational tools to generate structural models for U20 and U21 proteins, which are predicted to adopt MHC-Ia-like folds with closed MHC platforms and immunoglobulin-like domains. We evaluate these structural models and place them within current understanding of the structural basis for viral immune evasion of T cell and natural killer cell recognition.
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Affiliation(s)
- Grant C. Weaver
- Immunology and Microbiology Graduate Program, Morningside Graduate School of Biomedical Sciences, UMass Chan Medical School, Worcester, MA, United States
- Department of Pathology, UMass Chan Medical School, Worcester, MA, United States
| | - Richa Arya
- Department of Pathology, UMass Chan Medical School, Worcester, MA, United States
| | | | - Amy W. Hudson
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Lawrence J. Stern
- Immunology and Microbiology Graduate Program, Morningside Graduate School of Biomedical Sciences, UMass Chan Medical School, Worcester, MA, United States
- Department of Pathology, UMass Chan Medical School, Worcester, MA, United States
- Department of Biochemistry and Molecular Biotechnology, UMass Chan Medical School, Worcester, MA, United States
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6
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Chaouat AE, Seliger B, Mandelboim O, Schmiedel D. The HHV-6A Proteins U20 and U21 Target NKG2D Ligands to Escape Immune Recognition. Front Immunol 2021; 12:714799. [PMID: 34721381 PMCID: PMC8554080 DOI: 10.3389/fimmu.2021.714799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 09/16/2021] [Indexed: 11/13/2022] Open
Abstract
The coevolution of the human immune system and herpesviruses led to the emergence and diversification of both cellular danger molecules recognized by immune cells on the one hand and viral countermeasures that prevent the expression of these proteins on infected cells on the other. There are eight ligands for the activating receptor NKG2D in humans - MICA, MICB, ULBP1-6. Several of them are induced and surface-expressed on herpesvirus-infected cells to serve as danger signals to activate the immune system. Therefore, these ligands are frequently targeted for suppression by viral immune evasion mechanisms. Mechanisms to downregulate NKG2D ligands and thereby escape immune recognition have been identified in all other human herpesviruses (HHV), except for HHV-6A. In this study, we identify two HHV-6A encoded immunoevasins, U20 and U21, which suppress the expression of the NKG2D ligands ULBP1 and ULBP3, respectively, during infection. Additionally, MICB is targeted by a so far unexplored viral protein. Due to the diminished NKG2D ligand surface expression on infected cells, recognition of HHV-6A infected cells by innate immune cells is impaired. Importantly, our study indicates that immune escape mechanisms between the related herpesviruses HHV-6A and HHV-6B are evolutionary conserved as the same NKG2D ligands are targeted. Our data contribute an additional piece of evidence for the importance of the NKG2D receptor - NKG2D ligand axis during human herpesvirus infections and sheds light on immune evasion mechanisms of HHV-6A.
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Affiliation(s)
- Abigael Eva Chaouat
- The Lautenberg Center for General and Tumor Immunology, The BioMedical Research Institute Israel Canada of the Faculty of Medicine, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Barbara Seliger
- Martin Luther University, Institute of Medical Immunology, Halle-Wittenberg, Germany.,Department of GMP Development and ATMP Design, Fraunhofer Institute for Cell Therapy and Immunology (IZI), Leipzig, Germany
| | - Ofer Mandelboim
- The Lautenberg Center for General and Tumor Immunology, The BioMedical Research Institute Israel Canada of the Faculty of Medicine, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Dominik Schmiedel
- The Lautenberg Center for General and Tumor Immunology, The BioMedical Research Institute Israel Canada of the Faculty of Medicine, The Hebrew University Hadassah Medical School, Jerusalem, Israel.,Department of GMP Development and ATMP Design, Fraunhofer Institute for Cell Therapy and Immunology (IZI), Leipzig, Germany
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7
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Abstract
Like all herpesviruses, the roseoloviruses (HHV6A, -6B, and -7) establish lifelong infection within their host, requiring these viruses to evade host antiviral responses. One common host-evasion strategy is the downregulation of host-encoded, surface-expressed glycoproteins. Roseoloviruses have been shown to evade the host immune response by downregulating NK-activating ligands, class I MHC, and the TCR/CD3 complex. To more globally identify glycoproteins that are differentially expressed on the surface of HHV6A-infected cells, we performed cell surface capture of N-linked glycoproteins present on the surface of T cells infected with HHV6A, and compared these to proteins present on the surface of uninfected T cells. We found that the protein tyrosine phosphatase CD45 is downregulated in T cells infected with HHV6A. We also demonstrated that CD45 is similarly downregulated in cells infected with HHV7. CD45 is essential for signaling through the T cell receptor and, as such, is necessary for developing a fully functional immune response. Interestingly, the closely related betaherpesviruses human cytomegalovirus (HCMV) and murine cytomegalovirus (MCMV) have also separately evolved unique mechanisms to target CD45. While HCMV and MCMV target CD45 signaling and trafficking, HHV6A acts to downregulate CD45 transcripts. IMPORTANCE Human herpesviruses-6 and -7 infect essentially 100% of the world's population before the age of 5 and then remain latent or persistent in their host throughout life. As such, these viruses are among the most pervasive and stealthy of all viruses. Host immune cells rely on the presence of surface-expressed proteins to identify and target virus-infected cells. Here, we investigated the changes that occur to proteins expressed on the cell surface of T cells after infection with human herpesvirus-6A. We discovered that HHV-6A infection results in a reduction of CD45 on the surface of infected T cells and impaired activation in response to T cell receptor stimulation.
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Jiang X, Tang T, Guo J, Wang Y, Li P, Chen X, Wang L, Wen Y, Jia J, Emanuela G, Hu B, Chen S, Yao K, Li L, Tang H. Human Herpesvirus 6B U26 Inhibits the Activation of the RLR/MAVS Signaling Pathway. mBio 2021; 12:e03505-20. [PMID: 33593967 PMCID: PMC8545120 DOI: 10.1128/mbio.03505-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 01/04/2021] [Indexed: 01/15/2023] Open
Abstract
U26 is one of the roseolovirus unique genes with unknown function. Human herpesvirus 6B (HHV-6B) pU26 is predicted to be an 8-transmembrane protein containing a mitochondrion location signal. Here, we analyzed U26 function during HHV-6B infection and find that (i) HHV-6B U26 is expressed at a very early stage during HHV-6B infection, and knockdown of it results in a significant decrease of HHV-6B progeny virus production; (ii) U26 inhibits the activation of the retinoic acid-inducible gene I (RIG-I)-like receptor (RLR)/mitochondrial antiviral signaling protein (MAVS) signaling pathway, an important anti-HHV-6B infection innate immune response, by targeting MAVS protein for degradation; and (iii) a portion of U26 locates to the mitochondria, which could affect the mitochondrial membrane potential and finally leads to MAVS degradation. These findings indicate that HHV-6B U26 is a novel antagonistic viral factor against host innate antiviral immunity.IMPORTANCE HHV-6B (human herpesvirus 6B) is well known to evade host antiviral responses and establish a lifelong latent infection. How HHV-6B evades RNA recognition is still poorly understood. Our results indicate that HHV-6 U26 plays a vital role in RLR/MAVS signaling pathway activity. Knockout of endogenous MAVS could facilitate HHV-6B replication. The findings in this study could provide new insights into host-virus interactions and help develop a new therapy against HHV-6B infection.
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Affiliation(s)
- Xuefeng Jiang
- Department of Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Tian Tang
- Department of Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Jinfeng Guo
- Department of Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Yuhang Wang
- Department of Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Peipei Li
- Department of Women's Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, People's Republic of China
| | - Xiangjun Chen
- Department of Women's Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, People's Republic of China
| | - Lily Wang
- Department of Women's Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, People's Republic of China
| | - Yiqun Wen
- Department of Women's Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, People's Republic of China
| | - Junli Jia
- Department of Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Garbarino Emanuela
- Department of Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Benshun Hu
- Department of Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Shuhua Chen
- Department of Critical Care Medicine, Changzhou Cancer Hospital Affiliated to Soochow University, Changzhou, People's Republic of China
| | - Kun Yao
- Department of Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Linyun Li
- Department of Medical Genetics, Nanjing Medical University, Nanjing, People's Republic of China
| | - Huaming Tang
- Department of Immunology, Nanjing Medical University, Nanjing, People's Republic of China
- Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing, People's Republic of China
- The Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, People's Republic of China
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9
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Soh TK, Davies CTR, Muenzner J, Hunter LM, Barrow HG, Connor V, Bouton CR, Smith C, Emmott E, Antrobus R, Graham SC, Weekes MP, Crump CM. Temporal Proteomic Analysis of Herpes Simplex Virus 1 Infection Reveals Cell-Surface Remodeling via pUL56-Mediated GOPC Degradation. Cell Rep 2020; 33:108235. [PMID: 33027661 PMCID: PMC7539533 DOI: 10.1016/j.celrep.2020.108235] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 07/15/2020] [Accepted: 09/15/2020] [Indexed: 12/12/2022] Open
Abstract
Herpesviruses are ubiquitous in the human population and they extensively remodel the cellular environment during infection. Multiplexed quantitative proteomic analysis over the time course of herpes simplex virus 1 (HSV-1) infection was used to characterize changes in the host-cell proteome and the kinetics of viral protein production. Several host-cell proteins are targeted for rapid degradation by HSV-1, including the cellular trafficking factor Golgi-associated PDZ and coiled-coil motif-containing protein (GOPC). We show that the poorly characterized HSV-1 pUL56 directly binds GOPC, stimulating its ubiquitination and proteasomal degradation. Plasma membrane profiling reveals that pUL56 mediates specific changes to the cell-surface proteome of infected cells, including loss of interleukin-18 (IL18) receptor and Toll-like receptor 2 (TLR2), and that cell-surface expression of TLR2 is GOPC dependent. Our study provides significant resources for future investigation of HSV-host interactions and highlights an efficient mechanism whereby a single virus protein targets a cellular trafficking factor to modify the surface of infected cells. Multiplexed proteomic screens reveal regulation of host protein abundance by HSV-1 HSV-1 pUL56 targets host proteins such as GOPC for proteasomal degradation HSV-1-mediated degradation of GOPC remodels the plasma membrane of infected cells GOPC is important for cell-surface expression of immune receptor TLR2 in keratinocytes
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Affiliation(s)
- Timothy K Soh
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Colin T R Davies
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Julia Muenzner
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Leah M Hunter
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Henry G Barrow
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Viv Connor
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Clément R Bouton
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Cameron Smith
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Edward Emmott
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Robin Antrobus
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Stephen C Graham
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Michael P Weekes
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Colin M Crump
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK.
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10
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Wu Z, Jia J, Xu X, Xu M, Peng G, Ma J, Jiang X, Yao J, Yao K, Li L, Tang H. Human herpesvirus 6A promotes glycolysis in infected T cells by activation of mTOR signaling. PLoS Pathog 2020; 16:e1008568. [PMID: 32516328 PMCID: PMC7282626 DOI: 10.1371/journal.ppat.1008568] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/22/2020] [Indexed: 12/13/2022] Open
Abstract
Human herpesvirus 6 (HHV-6) is an important immunosuppressive and immunomodulatory virus worldwide. However, whether and how HHV-6 infection influences the metabolic machinery of the host cell to provide the energy and biosynthetic resources for virus propagation remains unknown. In this study, we identified that HHV-6A infection promotes glucose metabolism in infected T cells, resulting in elevated glycolytic activity with an increase of glucose uptake, glucose consumption and lactate secretion. Furthermore, we explored the mechanisms involved in HHV-6A-mediated glycolytic activation in the infected T cells. We found increased expressions of the key glucose transporters and glycolytic enzymes in HHV-6A-infected T cells. In addition, HHV-6A infection dramatically activated AKT-mTORC1 signaling in the infected T cells and pharmacological inhibition of mTORC1 blocked HHV-6A-mediated glycolytic activation. We also found that direct inhibition of glycolysis by 2-Deoxy-D-glucose (2-DG) or inhibition of mTORC1 activity in HHV-6A-infected T cells effectively reduced HHV-6 DNA replication, protein synthesis and virion production. These results not only reveal the mechanism of how HHV-6 infection affects host cell metabolism, but also suggest that targeting the metabolic pathway could be a new avenue for HHV-6 therapy.
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Affiliation(s)
- Zhisheng Wu
- Department of Immunology, Nanjing Medical University, Nanjing, P. R. China
| | - Junli Jia
- Department of Immunology, Nanjing Medical University, Nanjing, P. R. China
| | - Xianyi Xu
- Department of Immunology, Nanjing Medical University, Nanjing, P. R. China
| | - Mengyuan Xu
- Department of Immunology, Nanjing Medical University, Nanjing, P. R. China
| | - Guangyong Peng
- Division of Infectious Diseases, Allergy & Immunology and Department of Internal Medicine, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Jingjing Ma
- Department of Immunology, Nanjing Medical University, Nanjing, P. R. China
| | - Xuefeng Jiang
- Department of Immunology, Nanjing Medical University, Nanjing, P. R. China
| | - Jialin Yao
- Department of Immunology, Nanjing Medical University, Nanjing, P. R. China
| | - Kun Yao
- Department of Immunology, Nanjing Medical University, Nanjing, P. R. China
| | - Lingyun Li
- Department of Medical Genetics, Nanjing Medical University, Nanjing, P. R. China
- * E-mail: (LL); (HT)
| | - Huamin Tang
- Department of Immunology, Nanjing Medical University, Nanjing, P. R. China
- Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing, P. R. China
- * E-mail: (LL); (HT)
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11
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Abstract
The WW domain is a modular protein structure that recognizes the proline-rich Pro-Pro-x-Tyr (PPxY) motif contained in specific target proteins. The compact modular nature of the WW domain makes it ideal for mediating interactions between proteins in complex networks and signaling pathways of the cell (e.g. the Hippo pathway). As a result, WW domains play key roles in a plethora of both normal and disease processes. Intriguingly, RNA and DNA viruses have evolved strategies to hijack cellular WW domain-containing proteins and thereby exploit the modular functions of these host proteins for various steps of the virus life cycle, including entry, replication, and egress. In this review, we summarize key findings in this rapidly expanding field, in which new virus-host interactions continue to be identified. Further unraveling of the molecular aspects of these crucial virus-host interactions will continue to enhance our fundamental understanding of the biology and pathogenesis of these viruses. We anticipate that additional insights into these interactions will help support strategies to develop a new class of small-molecule inhibitors of viral PPxY-host WW-domain interactions that could be used as antiviral therapeutics.
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Affiliation(s)
- Ariel Shepley-McTaggart
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Hao Fan
- Bioinformatics Institute, Agency for Science, Technology, and Research (A*STAR), 30 Biopolis Street, Matrix #07-01, Singapore 138671.,Department of Biological Sciences (DBS), National University of Singapore, Singapore 119077.,Center for Computational Biology, DUKE-NUS Medical School, Singapore 169857
| | - Marius Sudol
- Department of Physiology, National University of Singapore, Singapore 119077.,Laboratory of Cancer Signaling and Domainopathies, Yong Loo Li School of Medicine, Block MD9, 2 Medical Drive #04-01, Singapore 117597.,Mechanobiology Institute, T-Lab, 5A Engineering Drive 1, Singapore 117411.,Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Ronald N Harty
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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12
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Bayliss RJ, Piguet V. Masters of manipulation: Viral modulation of the immunological synapse. Cell Microbiol 2018; 20:e12944. [PMID: 30123959 PMCID: PMC6492149 DOI: 10.1111/cmi.12944] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/01/2018] [Accepted: 08/14/2018] [Indexed: 02/06/2023]
Abstract
In order to thrive, viruses have evolved to manipulate host cell machinery for their own benefit. One major obstacle faced by pathogens is the immunological synapse. To enable efficient replication and latency in immune cells, viruses have developed a range of strategies to manipulate cellular processes involved in immunological synapse formation to evade immune detection and control T-cell activation. In vitro, viruses such as human immunodeficiency virus 1 and human T-lymphotropic virus type 1 utilise structures known as virological synapses to aid transmission of viral particles from cell to cell in a process termed trans-infection. The formation of the virological synapse provides a gateway for virus to be transferred between cells avoiding the extracellular space, preventing antibody neutralisation or recognition by complement. This review looks at how viruses are able to subvert intracellular signalling to modulate immune function to their advantage and explores the role synapse formation has in viral persistence and cell-to-cell transmission.
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Affiliation(s)
- Rebecca J. Bayliss
- Division of Infection and Immunity, School of MedicineCardiff UniversityCardiffUK
| | - Vincent Piguet
- Division of Infection and Immunity, School of MedicineCardiff UniversityCardiffUK
- Division of Dermatology, Department of MedicineUniversity of TorontoTorontoOntarioCanada
- Division of DermatologyWomen's College HospitalTorontoOntarioCanada
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13
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Abdolmaleki M, Yeap SK, Tan SW, Satharasinghe DA, Bello MB, Jahromi MZ, Bejo MH, Omar AR, Ideris A. Effects of Newcastle Disease Virus Infection on Chicken Intestinal Intraepithelial Natural Killer Cells. Front Immunol 2018; 9:1386. [PMID: 29973933 PMCID: PMC6019501 DOI: 10.3389/fimmu.2018.01386] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 06/04/2018] [Indexed: 11/13/2022] Open
Abstract
The intestinal intraepithelial natural killer cells (IEL-NK) are among the earliest effectors of antiviral immunity in chicken. Unfortunately, their role during Newcastle disease virus (NDV) infection remains obscure. Previous study has reported the development of a monoclonal antibody (mAb) known as 28-4, which is specifically directed against the CD3- IEL-NK cells. In the present study, we used this mAb to investigate the effects of velogenic and lentogenic NDV infection on avian IEL-NK cells. Our findings revealed that chickens infected with velogenic NDV strains have a reduced population of purified CD3-/28-4+ IEL-NK cells as determined by flow cytometry. Furthermore, the CD3-/28-4+ IEL-NK cells from chicken infected with velogenic NDV strains were shown to have a downregulated expression of activating receptors (CD69 and B-Lec), effector peptide (NK-LYSIN), and IFN gamma. On the contrary, the expression of the inhibitory receptor (B-NK) and bifunctional receptor (CHIR-AB1) were upregulated on these purified CD3-/28-4+ IEL-NK cells following velogenic NDV infection. Meanwhile, the lentogenic NDV demonstrated insignificant effects on both the total population of CD3-/28-4+ IEL-NK cells and the expression of their surface receptors. In addition, using real-time PCR and transmission electron microscopy, we showed that CD3-/28-4+ IEL-NK cells were susceptible to velogenic but not lentogenic NDV infection. These findings put together demonstrate the ability of different strains of NDV to manipulate the activating and inhibitory receptors of CD3-/28-4+ IEL-NK cells following infection. Further studies are, however, required to ascertain the functional importance of these findings during virulent or avirulent NDV infection.
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Affiliation(s)
- Mostafa Abdolmaleki
- Laboratory of Vaccines and Immunotherapeutic, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
| | - Swee Keong Yeap
- Laboratory of Vaccines and Immunotherapeutic, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
- China Asean College of Marine Science, Xiamen University Malaysia, Sepang, Malaysia
| | - Sheau Wei Tan
- Laboratory of Vaccines and Immunotherapeutic, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
| | - Dilan Amila Satharasinghe
- Laboratory of Vaccines and Immunotherapeutic, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
| | - Muhammad Bashir Bello
- Laboratory of Vaccines and Immunotherapeutic, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
| | - Mohammad Zareian Jahromi
- Laboratory of Vaccines and Immunotherapeutic, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
| | - Mohd Hair Bejo
- Laboratory of Vaccines and Immunotherapeutic, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
- Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Malaysia
| | - Abdul Rahman Omar
- Laboratory of Vaccines and Immunotherapeutic, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
- Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Malaysia
| | - Aini Ideris
- Laboratory of Vaccines and Immunotherapeutic, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
- Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Malaysia
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14
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Eliassen E, Krueger G, Luppi M, Ablashi D. Lymphoproliferative Syndromes Associated with Human Herpesvirus-6A and Human Herpesvirus-6B. Mediterr J Hematol Infect Dis 2018; 10:e2018035. [PMID: 29755712 PMCID: PMC5937953 DOI: 10.4084/mjhid.2018.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 12/28/2022] Open
Abstract
Human herpesvirus 6A and 6B (HHV-6A and HHV-6B) have been noted since their discovery for their T-lymphotropism. Although it has proven difficult to determine the extent to which HHV-6A and HHV-6B are involved in the pathogenesis of many diseases, evidence suggests that primary infection and reactivation of both viruses may induce or contribute to the progression of several lymphoproliferative disorders, ranging from benign to malignant and including infectious mononucleosis-like illness, drug induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS), and nodular sclerosis Hodgkin's lymphoma. Herein, we discuss the conditions associated with the lymphoproliferative capacity of HHV-6, as well as the potential mechanisms behind them. Continued exploration on this topic may add to our understanding of the interactions between HHV-6 and the immune system and may open the doors to more accurate diagnosis and treatment of certain lymphoproliferative disorders.
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Affiliation(s)
- Eva Eliassen
- HHV-6 Foundation, Santa Barbara, California, USA
| | - Gerhard Krueger
- Department of Pathology and Laboratory Medicine, University of Texas, Houston, Texas, USA
| | - Mario Luppi
- Department of Medical and Surgical Sciences, University of Modena and Reggio Emilia, Modena, Italy
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15
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Abstract
Nedd4 is a family of ubiquitin E3 ligases that regulate numerous cellular processes. In this report, we showed that alpha- and beta-herpesviruses have membrane proteins that regulate the function of the Nedd4 family members. Although the homology search score was quite low, UL56 of herpes simplex virus type 1 and 2, ORF0 of varicella-zoster virus, UL42 of human cytomegalovirus, and U24 of human herpesvirus 6A, 6B, and 7 all possess at least one PPxY (PY) motif in their cytoplasmic domain, and are able to bind with Itch, a member of the Nedd4 family. These viral proteins altered the localization of Itch and decreased Itch expression in co-expressing cells. In addition, these viral proteins reduced the production of retrovirus vectors through the regulation of the Nedd4 family of proteins. U24, but not the other proteins, effectively reduced CD3ε expression on the T cell surface. These viral molecules are thought to contribute to the specific function of each virus through the regulation of Nedd4 family activity.
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16
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Telford M, Navarro A, Santpere G. Whole genome diversity of inherited chromosomally integrated HHV-6 derived from healthy individuals of diverse geographic origin. Sci Rep 2018; 8:3472. [PMID: 29472617 PMCID: PMC5823862 DOI: 10.1038/s41598-018-21645-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 01/31/2018] [Indexed: 12/13/2022] Open
Abstract
Human herpesviruses 6-A and -B (HHV-6A, HHV-6B) are ubiquitous in human populations worldwide. These viruses have been associated with several diseases such as multiple sclerosis, Hodgkin's lymphoma or encephalitis. Despite of the need to understand the genetic diversity and geographic stratification of these viruses, the availability of complete viral sequences from different populations is still limited. Here, we present nine new inherited chromosomally integrated HHV-6 sequences from diverse geographical origin which were generated through target DNA enrichment on lymphoblastoid cell lines derived from healthy individuals. Integration with available HHV-6 sequences allowed the assessment of HHV-6A and -6B phylogeny, patterns of recombination and signatures of natural selection. Analysis of the intra-species variability showed differences between A and B diversity levels and revealed that the HHV-6B reference (Z29) is an uncommon sequence, suggesting the need for an alternative reference sequence. Signs of geographical variation are present and more defined in HHV-6A, while they appear partly masked by recombination in HHV-6B. Finally, we conducted a scan for signatures of selection in protein coding genes that yielded at least 6 genes (4 and 2 respectively for the A and B species) showing significant evidence for accelerated evolution, and 1 gene showing evidence of positive selection in HHV-6A.
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Affiliation(s)
- Marco Telford
- Institute of Evolutionary Biology (UPF-CSIC), Departament de Ciències Experimentals i la Salut, Universitat Pompeu Fabra, PRBB, Barcelona, Catalonia, Spain
| | - Arcadi Navarro
- Institute of Evolutionary Biology (UPF-CSIC), Departament de Ciències Experimentals i la Salut, Universitat Pompeu Fabra, PRBB, Barcelona, Catalonia, Spain.
- National Institute for Bioinformatics (INB), PRBB, Barcelona, Catalonia, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), PRBB, Barcelona, Catalonia, Spain.
- Center for Genomic Regulation (CRG), PRBB, Barcelona, Catalonia, Spain.
| | - Gabriel Santpere
- Institute of Evolutionary Biology (UPF-CSIC), Departament de Ciències Experimentals i la Salut, Universitat Pompeu Fabra, PRBB, Barcelona, Catalonia, Spain.
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, 06510, USA.
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17
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Iseka FM, Goetz BT, Mushtaq I, An W, Cypher LR, Bielecki TA, Tom EC, Arya P, Bhattacharyya S, Storck MD, Semerad CL, Talmadge JE, Mosley RL, Band V, Band H. Role of the EHD Family of Endocytic Recycling Regulators for TCR Recycling and T Cell Function. THE JOURNAL OF IMMUNOLOGY 2017; 200:483-499. [PMID: 29212907 DOI: 10.4049/jimmunol.1601793] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 11/01/2017] [Indexed: 12/31/2022]
Abstract
T cells use the endocytic pathway for key cell biological functions, including receptor turnover and maintenance of the immunological synapse. Some of the established players include the Rab GTPases, the SNARE complex proteins, and others, which function together with EPS-15 homology domain-containing (EHD) proteins in non-T cell systems. To date, the role of the EHD protein family in T cell function remains unexplored. We generated conditional EHD1/3/4 knockout mice using CD4-Cre and crossed these with mice bearing a myelin oligodendrocyte glycoprotein-specific TCR transgene. We found that CD4+ T cells from these mice exhibited reduced Ag-driven proliferation and IL-2 secretion in vitro. In vivo, these mice exhibited reduced severity of experimental autoimmune encephalomyelitis. Further analyses showed that recycling of the TCR-CD3 complex was impaired, leading to increased lysosomal targeting and reduced surface levels on CD4+ T cells of EHD1/3/4 knockout mice. Our studies reveal a novel role of the EHD family of endocytic recycling regulatory proteins in TCR-mediated T cell functions.
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Affiliation(s)
- Fany M Iseka
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198
| | - Benjamin T Goetz
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198
| | - Insha Mushtaq
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198
| | - Wei An
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198
| | - Luke R Cypher
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198
| | - Timothy A Bielecki
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198
| | - Eric C Tom
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198
| | - Priyanka Arya
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198
| | - Sohinee Bhattacharyya
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198
| | - Matthew D Storck
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198
| | - Craig L Semerad
- Flow Cytometry Research Facility, University of Nebraska Medical Center, Omaha, NE 68198; and
| | - James E Talmadge
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198
| | - R Lee Mosley
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198.,Fred and Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198
| | - Vimla Band
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198
| | - Hamid Band
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198; .,Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198.,Fred and Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198
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18
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Vaitaitis GM, Waid DM, Yussman MG, Wagner DH. CD40-mediated signalling influences trafficking, T-cell receptor expression, and T-cell pathogenesis, in the NOD model of type 1 diabetes. Immunology 2017; 152:243-254. [PMID: 28542921 DOI: 10.1111/imm.12761] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 04/27/2017] [Accepted: 05/08/2017] [Indexed: 12/23/2022] Open
Abstract
CD40 plays a critical role in the pathogenesis of type 1 diabetes (T1D). The mechanism of action, however, is undetermined, probably because CD40 expression has been grossly underestimated. CD40 is expressed on numerous cell types that now include T cells and pancreatic β cells. CD40+ CD4+ cells [T helper type 40 (TH40)] prove highly pathogenic in NOD mice and in translational human T1D studies. We generated BDC2.5.CD40-/- and re-derived NOD.CD154-/- mice to better understand the CD40 mechanism of action. Fully functional CD40 expression is required not only for T1D development but also for insulitis. In NOD mice, TH40 cell expansion in pancreatic lymph nodes occurs before insulitis and demonstrates an activated phenotype compared with conventional CD4+ cells, apparently regardless of antigen specificity. TH40 T-cell receptor (TCR) usage demonstrates increases in several Vα and Vβ species, particularly Vα3.2+ that arise early and are sustained throughout disease development. TH40 cells isolated from diabetic pancreas demonstrate a relatively broad TCR repertoire rather than restricted clonal expansions. The expansion of the Vα/Vβ species associated with diabetes depends upon CD40 signalling; NOD.CD154-/- mice do not expand the same TCR species. Finally, CD40-mediated signals significantly increase pro-inflammatory Th1- and Th17-associated cytokines whereas CD28 co-stimulus alternatively promotes regulatory cytokines.
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Affiliation(s)
- Gisela M Vaitaitis
- The Webb-Waring Center, The University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Dan M Waid
- The Webb-Waring Center, The University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Martin G Yussman
- The Webb-Waring Center, The University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - David H Wagner
- The Webb-Waring Center, The University of Colorado Anschutz Medical Campus, Aurora, CO, USA.,Division of Pulmonary Sciences and Critical Care, Department of Medicine, The University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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19
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A Murine Herpesvirus Closely Related to Ubiquitous Human Herpesviruses Causes T-Cell Depletion. J Virol 2017; 91:JVI.02463-16. [PMID: 28179532 PMCID: PMC5391440 DOI: 10.1128/jvi.02463-16] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 01/26/2017] [Indexed: 12/14/2022] Open
Abstract
The human roseoloviruses human herpesvirus 6A (HHV-6A), HHV-6B, and HHV-7 comprise the Roseolovirus genus of the human Betaherpesvirinae subfamily. Infections with these viruses have been implicated in many diseases; however, it has been challenging to establish infections with roseoloviruses as direct drivers of pathology, because they are nearly ubiquitous and display species-specific tropism. Furthermore, controlled study of infection has been hampered by the lack of experimental models, and until now, a mouse roseolovirus has not been identified. Herein we describe a virus that causes severe thymic necrosis in neonatal mice, characterized by a loss of CD4+ T cells. These phenotypes resemble those caused by the previously described mouse thymic virus (MTV), a putative herpesvirus that has not been molecularly characterized. By next-generation sequencing of infected tissue homogenates, we assembled a contiguous 174-kb genome sequence containing 128 unique predicted open reading frames (ORFs), many of which were most closely related to herpesvirus genes. Moreover, the structure of the virus genome and phylogenetic analysis of multiple genes strongly suggested that this virus is a betaherpesvirus more closely related to the roseoloviruses, HHV-6A, HHV-6B, and HHV-7, than to another murine betaherpesvirus, mouse cytomegalovirus (MCMV). As such, we have named this virus murine roseolovirus (MRV) because these data strongly suggest that MRV is a mouse homolog of HHV-6A, HHV-6B, and HHV-7.IMPORTANCE Herein we describe the complete genome sequence of a novel murine herpesvirus. By sequence and phylogenetic analyses, we show that it is a betaherpesvirus most closely related to the roseoloviruses, human herpesviruses 6A, 6B, and 7. These data combined with physiological similarities with human roseoloviruses collectively suggest that this virus is a murine roseolovirus (MRV), the first definitively described rodent roseolovirus, to our knowledge. Many biological and clinical ramifications of roseolovirus infection in humans have been hypothesized, but studies showing definitive causative relationships between infection and disease susceptibility are lacking. Here we show that MRV infects the thymus and causes T-cell depletion, suggesting that other roseoloviruses may have similar properties.
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20
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Sang Y, Zhang R, Creagh AL, Haynes CA, Straus SK. Interactions of U24 from Roseolovirus with WW domains: canonical vs noncanonical. Biochem Cell Biol 2017; 95:350-358. [PMID: 28314105 DOI: 10.1139/bcb-2016-0250] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
U24 is a C-terminal membrane-anchored protein found in both human herpes virus type 6 and 7 (HHV-6 and HHV-7), with an N-terminal segment that is rich in prolines (PPxY motif in both HHV-6A and 7; PxxP motif in HHV-6A). Previous work has shown that U24 interacts strongly with Nedd4 WW domains, in particular, hNedd4L-WW3*. It was also shown that this interaction depends strongly on the nature of the amino acids that are upstream from the PY motif in U24. In this contribution, data was obtained from pull-downs, isothermal titration calorimetry, and NMR to further determine what modulates U24:WW domain interactions. Specifically, 3 non-canonical WW domains from human Smad ubiquitination regulatory factor (Smurf), namely hSmurf2-WW2, hSmurf2-WW3, and a tandem construct hSmurf2-WW2 + 3, were studied. Overall, the interactions between U24 and these Smurf WW domains were found to be weaker than those in U24:Nedd4 WW domain pairs, suggesting that U24 function is tightly linked to specific E3 ubiqitin ligases.
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Affiliation(s)
- Yurou Sang
- a Department of Chemistry, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Rui Zhang
- a Department of Chemistry, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - A Louise Creagh
- b Michael Smith Laboratories and Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Charles A Haynes
- b Michael Smith Laboratories and Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Suzana K Straus
- a Department of Chemistry, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
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21
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Sang Y, Zhang R, Scott WRP, Creagh AL, Haynes CA, Straus SK. U24 from Roseolovirus interacts strongly with Nedd4 WW Domains. Sci Rep 2017; 7:39776. [PMID: 28051106 PMCID: PMC5209733 DOI: 10.1038/srep39776] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/28/2016] [Indexed: 01/20/2023] Open
Abstract
U24 is a protein found in both roseoloviruses Human Herpes Virus type 6 and 7 (HHV-6 and HHV-7), with an N-terminus that is rich in prolines (PY motif in both HHV-6A and 7; PxxP motif in HHV-6A). Previous work has shown that the interaction between U24 and WW domains is important for endocytic recycling of T-cell receptors, but a cognate ligand was never identified. In this contribution, data was obtained from pull-downs, ITC, NMR and molecular dynamics simulations to show that a specific interaction exists between U24 and Nedd4 WW domains. ITC experiments were also carried out for U24 from HHV-6A phosphorylated at Thr6 (pU24-6A) and a peptide containing the PY motif from Nogo-A, a protein implicated in both the initial inflammatory and the neurodegenerative phases of multiple sclerosis (MS). The results suggest that phosphorylation of U24 from HHV-6A may be crucial for its potential role in MS.
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Affiliation(s)
- Yurou Sang
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Rui Zhang
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Walter R P Scott
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
| | - A Louise Creagh
- Michael Smith Laboratories and Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Charles A Haynes
- Michael Smith Laboratories and Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Suzana K Straus
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
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22
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Human Herpesvirus 6B Downregulates Expression of Activating Ligands during Lytic Infection To Escape Elimination by Natural Killer Cells. J Virol 2016; 90:9608-9617. [PMID: 27535049 DOI: 10.1128/jvi.01164-16] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/03/2016] [Indexed: 12/26/2022] Open
Abstract
The Herpesviridae family consists of eight viruses, most of which infect a majority of the human population. One of the less-studied members is human herpesvirus 6 (HHV-6) (Roseolovirus), which causes a mild, well-characterized childhood disease. Primary HHV-6 infection is followed by lifelong latency. Reactivation frequently occurs in immunocompromised patients, such as those suffering from HIV infection or cancer or following transplantation, and causes potentially life-threatening complications. In this study, we investigated the mechanisms that HHV-6 utilizes to remain undetected by natural killer (NK) cells, which are key participants in the innate immune response to infections. We revealed viral mechanisms which downregulate ligands for two powerful activating NK cell receptors: ULBP1, ULBP3, and MICB, which trigger NKG2D, and B7-H6, which activates NKp30. Accordingly, this downregulation impaired the ability of NK cells to recognize HHV-6-infected cells. Thus, we describe for the first time immune evasion mechanisms of HHV-6 that protect lytically infected cells from NK elimination. IMPORTANCE Human herpesvirus 6 (HHV-6) latently infects a large portion of the human population and can reactivate in humans lacking a functional immune system, such as cancer or AIDS patients. Under these conditions, it can cause life-threatening diseases. To date, the actions and interplay of immune cells, and particularly cells of the innate immune system, during HHV-6 infection are poorly defined. In this study, we aimed to understand how cells undergoing lytic HHV-6 infection interact with natural killer (NK) cells, innate lymphocytes constituting the first line of defense against viral intruders. We show that HHV-6 suppresses the expression of surface proteins that alert the immune cells by triggering two major receptors on NK cells, NKG2D and NKp30. As a consequence, HHV-6 can replicate undetected by the innate immune system and potentially spread infection throughout the body. This study advances the understanding of HHV-6 biology and the measures it uses to successfully escape immune elimination.
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23
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Koshizuka T, Tanaka K, Suzutani T. Degradation of host ubiquitin E3 ligase Itch by human cytomegalovirus UL42. J Gen Virol 2016; 97:196-208. [DOI: 10.1099/jgv.0.000336] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Tetsuo Koshizuka
- Department of Microbiology, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima 960-1295, Japan
| | - Keiichiro Tanaka
- Department of Microbiology, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima 960-1295, Japan
| | - Tatsuo Suzutani
- Department of Microbiology, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima 960-1295, Japan
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24
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Jasirwan C, Tang H, Kawabata A, Mori Y. The human herpesvirus 6 U21-U24 gene cluster is dispensable for virus growth. Microbiol Immunol 2015; 59:48-53. [PMID: 25346365 DOI: 10.1111/1348-0421.12208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/01/2014] [Accepted: 10/24/2014] [Indexed: 10/24/2022]
Abstract
Human herpesvirus 6 (HHV-6) is a T-lymphotrophic virus belongs to the genus Roseolovirus within the beta herpesvirus subfamily. The U20-U24 gene cluster is unique to Roseoloviruses; however, both their function and whether they are essential for virus growth is unknown. Recently, bacterial artificial chromosome (BAC) techniques have been used to investigate HHV-6A. This study describes generation of a virus genome lacking U21-U24 (HHV-6ABACΔU21-24) and shows that infectious virus particles can be reconstituted from this BAC DNA. Our data indicate that the HHV-6 U21-U24 gene cluster is dispensable for virus propagation.
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Affiliation(s)
- Chyntia Jasirwan
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Hyogo, Kobe, 650-0017, Japan
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The influence of dietary zinc source and coccidial vaccine exposure on intracellular zinc homeostasis and immune status in broiler chickens. Br J Nutr 2015; 114:202-12. [DOI: 10.1017/s0007114515001592] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Coccidia are protozoal parasites which compromise mucosal integrity of the intestine, potentiating poultry morbidity. The host's Zn status influences the course of infection. Therefore, two experiments were designed to determine how supplemental Zn regimens impacted jejunal and caecal immune status and Zn transporter expression. Coccivac®-B was administered weekly at ten times the recommended dose as a mild coccidial challenge (10CV). Zn was provided through a basal diet, supplemental zinc sulfate (ZnSO4), or a supplemental 1:1 blend of ZnSO4 and Availa®-Zn (Blend). Mucosal jejunum (Expt 1) and caecal tonsils (Expt 2) were evaluated for intracellular Zn concentrations and phagocytic capacity. Messenger expression of Zn transporters ZnT5, ZnT7, Zip9 and Zip13 were investigated to determine Zn trafficking. With 10CV, phagocytic capacity was decreased in jejunal cells by 2 %. In the caecal tonsils, however, phagocytic capacity increased with challenge, with the magnitude of increase being more pronounced with higher dietary Zn (10CV × Zn interaction; P= 0·04). Intracellular Zn within caecal tonsils was found significantly reduced with 10CV (27 %, P= 0·0001). 10CV also resulted in an overall increase in the ratio of Zip:ZnT transporters. With the exception of Zip13 transporter expression, dietary Zn source had little impact on any of the measured cellular parameters. Thus, intestinal mucosal tissues had reductions in intracellular free Zn during coccidial challenge, which was coupled with an upregulation of measured Zip transporters. This suggests that under coccidial challenge, intestinal cells attempt to compensate for the drop in intracellular Zn.
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Abstract
Cell surface receptors that have been internalized and enter the endocytic pathway have multiple fates including entrance into the multivesicular body pathway on their way to lysosomal degradation, recycling back to the cell surface, or retrograde trafficking out of the endolysosomal system back to the Golgi apparatus. Two ubiquitously expressed protein complexes, WASH and the endosomal coat complex retromer, function together to play a central role in directing the fate of receptors into the latter two pathways. In this chapter, we describe fluorescent- and flow cytometry-based methods for analyzing the recycling and retrograde trafficking of two receptors, α5β1 and CI-M6PR, whose intracellular fates are regulated by WASH and retromer activity. The guidelines presented in this chapter can be applied to the analysis of any cell surface or intracellular membrane protein to determine the impact of WASH or retromer deregulation on its intracellular trafficking route.
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Moraes L, Grille S, Morelli P, Mila R, Trias N, Brugnini A, LLuberas N, Biestro A, Lens D. Immune cells subpopulations in cerebrospinal fluid and peripheral blood of patients with Aneurysmal Subarachnoid Hemorrhage. SPRINGERPLUS 2015; 4:195. [PMID: 25977890 PMCID: PMC4414856 DOI: 10.1186/s40064-015-0970-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 04/07/2015] [Indexed: 11/29/2022]
Abstract
Background There is growing evidence supporting the role of inflammation in aneurysmal subarachnoid hemorrhage (aSAH) pathophysiology and it is of great interest to elucidate which immune mechanisms are involved. Methods 12 aSAH patients and 28 healthy controls were enrolled prospectively. We assessed leukocytes subpopulations and their activation status by flow cytometry in cerebrospinal fluid (CSF) and peripheral blood (PB) of SAH patients at the same time and in PB of controls. Results Monocytes and neutrophils were activated in CSF of aSAH patients. The percentage of CD14++CD16+ monocytes were higher in CSF than in PB of aSAH patients, and were also increased in PB of aSAH patients compared with controls. An enhanced expression of CD69 was shown in CSF neutrophils compared with PB in aSAH patients. PB of aSAH patients showed lower percentage of total lymphocytes compared with controls PB. Additionally, lymphocytes were activated in CSF and PB of aSAH patients. CD4+ and CD8+ T cells had a decreased expression on CD3 and higher levels of CD69 in CSF compared with PB in aSAH patients. Moreover, PB CD4+ and CD8+ T cells of aSAH patients were activated compared with controls. Additionally, CD28 expression was decreased on CSF T lymphocytes. Conclusions Our data suggest an important recruitment of leukocytes to the site of injury in aSAH as well as an increased activation at this level. Overall, these results indicate that aSAH probably stimulates both the innate and adaptive immune responses.
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Affiliation(s)
- Leandro Moraes
- Cátedra de Medicina Intensiva. Hospital de Clínicas. Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.,Cátedra de Hematología. Hospital de Clínicas. Facultad de Medicina, Universidad de la República, Avda. Italia s.n, CP 11300 Montevideo, Uruguay
| | - Sofía Grille
- Cátedra de Hematología. Hospital de Clínicas. Facultad de Medicina, Universidad de la República, Avda. Italia s.n, CP 11300 Montevideo, Uruguay.,Departamento Básico de Medicina, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Paula Morelli
- Cátedra de Medicina Intensiva. Hospital de Clínicas. Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Rafael Mila
- Departamento de Cardiología. Hospital de Clínicas. Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Natalia Trias
- Cátedra de Hematología. Hospital de Clínicas. Facultad de Medicina, Universidad de la República, Avda. Italia s.n, CP 11300 Montevideo, Uruguay
| | - Andreína Brugnini
- Cátedra de Hematología. Hospital de Clínicas. Facultad de Medicina, Universidad de la República, Avda. Italia s.n, CP 11300 Montevideo, Uruguay
| | - Natalia LLuberas
- Departamento de Cardiología. Hospital de Clínicas. Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Alberto Biestro
- Cátedra de Medicina Intensiva. Hospital de Clínicas. Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Daniela Lens
- Cátedra de Hematología. Hospital de Clínicas. Facultad de Medicina, Universidad de la República, Avda. Italia s.n, CP 11300 Montevideo, Uruguay
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Osborne DG, Piotrowski JT, Dick CJ, Zhang JS, Billadeau DD. SNX17 affects T cell activation by regulating TCR and integrin recycling. THE JOURNAL OF IMMUNOLOGY 2015; 194:4555-66. [PMID: 25825439 DOI: 10.4049/jimmunol.1402734] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 03/02/2015] [Indexed: 11/19/2022]
Abstract
A key component in T cell activation is the endosomal recycling of receptors to the cell surface, thereby allowing continual integration of signaling and Ag recognition. One protein potentially involved in TCR transport is sorting nexin 17 (SNX17). SNX proteins have been found to bind proteins involved in T cell activation, but specifically the role of SNX17 in receptor recycling and T cell activation is unknown. Using immunofluorescence, we find that SNX17 colocalizes with TCR and localizes to the immune synapse in T- conjugates. Significantly, knockdown of the SNX17 resulted in fewer T-APC conjugates, lower CD69, TCR, and LFA-1 surface expression, as well as lower overall TCR recycling compared with control T cells. Lastly, we identified the 4.1/ezrin/radixin/moesin domain of SNX17 as being responsible in the binding and trafficking of TCR and LFA-1 to the cell surface. These data suggest that SNX17 plays a role in the maintenance of normal surface levels of activating receptors and integrins to permit optimum T cell activation at the immune synapse.
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Affiliation(s)
- Douglas G Osborne
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905;Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905; andDivision of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905
| | - Joshua T Piotrowski
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905;Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905; andDivision of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905
| | - Christopher J Dick
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905;Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905; andDivision of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905
| | - Jin-San Zhang
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905;Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905; andDivision of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905
| | - Daniel D Billadeau
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905;Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905; andDivision of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905
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29
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Roseoloviruses and their modulation of host defenses. Curr Opin Virol 2014; 9:178-87. [DOI: 10.1016/j.coviro.2014.09.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 09/23/2014] [Accepted: 09/26/2014] [Indexed: 12/27/2022]
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Horvat B, Berges BK, Lusso P. Recent developments in animal models for human herpesvirus 6A and 6B. Curr Opin Virol 2014; 9:97-103. [PMID: 25462440 DOI: 10.1016/j.coviro.2014.09.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 09/18/2014] [Accepted: 09/23/2014] [Indexed: 12/30/2022]
Abstract
Progress in the identification of suitable animal models for human herpesvirus (HHV)-6A and HHV-6B infections has been slow. Recently, new models have been established, mainly for HHV-6A, which reproduce some pathological features seen in humans. Neuroinflammatory signs were observed in infected marmosets and CD46-transgenic mice; although viral replication was not prominent, persistence of viral DNA and specific immunologic responses were detected, suggesting an immune-mediated pathogenic mechanism. Pig-tailed macaques showed robust viral replication concomitant with acute-phase symptoms, and provided a model to study the effects of HHV-6A on AIDS progression. In humanized mice, viral replication was less evident, but infection led to T-cell alterations. Altogether, these recent developments have opened new perspectives for studying the pathogenic role of HHV-6A in humans.
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Affiliation(s)
- Branka Horvat
- CIRI, International Center for Infectiology Research, France; Inserm, U1111, Lyon, France; CNRS, UMR5308, Lyon, France; Université Lyon 1, Lyon, France; Ecole Normale Supérieure de Lyon, Lyon, France
| | - Bradford K Berges
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602, USA
| | - Paolo Lusso
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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31
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Cytomegalovirus immune evasion by perturbation of endosomal trafficking. Cell Mol Immunol 2014; 12:154-69. [PMID: 25263490 PMCID: PMC4654299 DOI: 10.1038/cmi.2014.85] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 08/15/2014] [Accepted: 08/16/2014] [Indexed: 12/30/2022] Open
Abstract
Cytomegaloviruses (CMVs), members of the herpesvirus family, have evolved a variety of mechanisms to evade the immune response to survive in infected hosts and to establish latent infection. They effectively hide infected cells from the effector mechanisms of adaptive immunity by eliminating cellular proteins (major histocompatibility Class I and Class II molecules) from the cell surface that display viral antigens to CD8 and CD4 T lymphocytes. CMVs also successfully escape recognition and elimination of infected cells by natural killer (NK) cells, effector cells of innate immunity, either by mimicking NK cell inhibitory ligands or by downregulating NK cell-activating ligands. To accomplish these immunoevasion functions, CMVs encode several proteins that function in the biosynthetic pathway by inhibiting the assembly and trafficking of cellular proteins that participate in immune recognition and thereby, block their appearance at the cell surface. However, elimination of these proteins from the cell surface can also be achieved by perturbation of their endosomal route and subsequent relocation from the cell surface into intracellular compartments. Namely, the physiological route of every cellular protein, including immune recognition molecules, is characterized by specific features that determine its residence time at the cell surface. In this review, we summarize the current understanding of endocytic trafficking of immune recognition molecules and perturbations of the endosomal system during infection with CMVs and other members of the herpesvirus family that contribute to their immune evasion mechanisms.
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32
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Sen N, Mukherjee G, Sen A, Bendall SC, Sung P, Nolan GP, Arvin AM. Single-cell mass cytometry analysis of human tonsil T cell remodeling by varicella zoster virus. Cell Rep 2014; 8:633-45. [PMID: 25043183 PMCID: PMC4127309 DOI: 10.1016/j.celrep.2014.06.024] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 05/17/2014] [Accepted: 06/17/2014] [Indexed: 12/11/2022] Open
Abstract
Although pathogens must infect differentiated host cells that exhibit substantial diversity, documenting the consequences of infection against this heterogeneity is challenging. Single-cell mass cytometry permits deep profiling based on combinatorial expression of surface and intracellular proteins. We used this method to investigate varicella-zoster virus (VZV) infection of tonsil T cells, which mediate viral transport to skin. Our results indicate that VZV induces a continuum of changes regardless of basal phenotypic and functional T cell characteristics. Contrary to the premise that VZV selectively infects T cells with skin trafficking profiles, VZV infection altered T cell surface proteins to enhance or induce these properties. Zap70 and Akt signaling pathways that trigger such surface changes were activated in VZV-infected naive and memory cells by a T cell receptor (TCR)-independent process. Single-cell mass cytometry is likely to be broadly relevant for demonstrating how intracellular pathogens modulate differentiated cells to support pathogenesis in the natural host.
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Affiliation(s)
- Nandini Sen
- Department of Pediatrics, Stanford University, Stanford, CA 94025, USA
| | - Gourab Mukherjee
- Department of Statistics, Stanford University, Stanford, CA 94025, USA; Department of Data Sciences and Operations, University of Southern California, Los Angeles, CA 90089, USA
| | - Adrish Sen
- Department of Medicine, Stanford University, Stanford, CA 94025, USA
| | - Sean C Bendall
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94025, USA
| | - Phillip Sung
- Department of Pediatrics, Stanford University, Stanford, CA 94025, USA
| | - Garry P Nolan
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94025, USA
| | - Ann M Arvin
- Department of Pediatrics, Stanford University, Stanford, CA 94025, USA; Department of Microbiology and Immunology, Stanford University, Stanford, CA 94025, USA.
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Graham DB, Osborne DG, Piotrowski JT, Gomez TS, Gmyrek GB, Akilesh HM, Dani A, Billadeau DD, Swat W. Dendritic cells utilize the evolutionarily conserved WASH and retromer complexes to promote MHCII recycling and helper T cell priming. PLoS One 2014; 9:e98606. [PMID: 24886983 PMCID: PMC4041763 DOI: 10.1371/journal.pone.0098606] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 05/06/2014] [Indexed: 01/19/2023] Open
Abstract
Immature dendritic cells (DCs) maintain a highly dynamic pool of recycling MHCII that promotes sampling of environmental antigens for presentation to T helper cells. However, the molecular basis of MHCII recycling and the cellular machinery that orchestrates MHCII trafficking are incompletely understood. Using a mouse model we show that WASH, an actin regulatory protein that facilitates retromer function, is essential for MHCII recycling and efficient priming of T helper cells. We further demonstrate that WASH deficiency results in impaired MHCII surface levels, recycling, and an accumulation of polyubiquitinated MHCII complexes, which are subsequently slated for premature lysosomal degradation. Consequently, conditional deletion of the Wash gene in DCs impairs priming of both conventional and autoimmune T helper cells in vivo and attenuates disease progression in a model of experimental autoimmune encephalitis (EAE). Thus, we identify a novel mechanism in which DCs employ the evolutionarily conserved WASH and retromer complex for MHCII recycling in order to regulate T helper cell priming.
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Affiliation(s)
- Daniel B. Graham
- Department of Pathology and Immunology, Division of Immunobiology, Washington University School of Medicine, St. Louis, Missouri, United States of America,
| | - Douglas G. Osborne
- Department of Immunology, Division of Oncology Research and Schulze Center for Novel Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Joshua T. Piotrowski
- Department of Immunology, Division of Oncology Research and Schulze Center for Novel Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Timothy S. Gomez
- Department of Immunology, Division of Oncology Research and Schulze Center for Novel Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Grzegorz B. Gmyrek
- Department of Pathology and Immunology, Division of Immunobiology, Washington University School of Medicine, St. Louis, Missouri, United States of America,
| | - Holly M. Akilesh
- Department of Pathology and Immunology, Division of Immunobiology, Washington University School of Medicine, St. Louis, Missouri, United States of America,
| | - Adish Dani
- Department of Pathology and Immunology, Division of Immunobiology, Washington University School of Medicine, St. Louis, Missouri, United States of America,
| | - Daniel D. Billadeau
- Department of Immunology, Division of Oncology Research and Schulze Center for Novel Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
- * E-mail: (WS); (DDB)
| | - Wojciech Swat
- Department of Pathology and Immunology, Division of Immunobiology, Washington University School of Medicine, St. Louis, Missouri, United States of America,
- * E-mail: (WS); (DDB)
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Characterization of the human herpesvirus 6A U23 gene. Virology 2013; 450-451:98-105. [PMID: 24503071 DOI: 10.1016/j.virol.2013.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Revised: 10/01/2013] [Accepted: 12/04/2013] [Indexed: 11/21/2022]
Abstract
Human herpesvirus 6 (HHV-6), which replicates abundantly in T cells, belongs to the Roseolovirus genus within the betaherpesvirus subfamily. Members of the Roseolovirus genus encode seven unique genes, U20, U21, U23, U24, U24A, U26, and U100. The present study focused on one of these, U23, by analyzing the characteristics of its gene product in HHV-6A-infected cells. The results indicated that the U23 protein was expressed at the late phase of infection as a glycoprotein, but was not incorporated into virions, and mostly stayed within the trans Golgi network (TGN) in HHV-6A-infected cells. Furthermore, analysis using a U23-defective mutant virus showed that the gene is nonessential for viral replication in vitro.
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T cells from autoimmune patients display reduced sensitivity to immunoregulation by mesenchymal stem cells: role of IL-2. Autoimmun Rev 2013; 13:187-96. [PMID: 24121085 DOI: 10.1016/j.autrev.2013.09.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Accepted: 09/26/2013] [Indexed: 12/16/2022]
Abstract
Mesenchymal stem cells (MSCs) are multipotent progenitor cells which have been shown to possess broad immunoregulatory and anti-inflammatory capabilities, making them a promising tool to treat autoimmune diseases (AIDs). Nevertheless, as in recent years T cells from AID patients have been found to resist suppression by regulatory T cells, the question of whether they could be regulated by MSCs arises. To use MSCs as a therapeutic tool in human autoimmune diseases, one prerequisite is that T cells from autoimmune patients will be sensitive to these stem cells. The aim of this work was to investigate the ability of healthy donor derived MSCs to inhibit the proliferation of T cells from two pathophysiologically different AIDs: Multiple Sclerosis (MS) and Myasthenia Gravis (MG). We show that MSC-induced inhibition of interferon-γ production and surface expression of the CD3, CD4 and CD28 receptors by activated lymphocytes was similar in the AID patients and healthy controls. Contrarily, the MSCs' ability to suppress the proliferation of T cells of both diseases was significantly weaker compared to their ability to affect T cells of healthy individuals. Although we found that the inhibitory mechanism is mediated through CD14+ monocytes, the faulty cellular component is the patients' T cells. MSC-treated MS and MG lymphocytes were shown to produce significantly more IL-2 than healthy subjects while coupling of the MSC treatment with neutralizing IL-2 antibodies resulted in inhibition levels similar to those of the healthy controls. MSCs were also found to down-regulate the lymphocyte surface expression of the IL-2 receptor (CD25) through both transcription inhibition and induction of receptor shedding. Addition of IL-2 to MSC-inhibited lymphocytes restored proliferation thus suggesting a key role played by this cytokine in the inhibitory mechanism. Taken together, these results demonstrate the potential of a MSC-based cellular therapy for MS, MG and possibly other autoimmune diseases but also highlight the need for a better understanding of the underlying mechanisms for development and optimization of clinical protocols.
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Human herpesvirus 6A partially suppresses functional properties of DC without viral replication. PLoS One 2013; 8:e58122. [PMID: 23526966 PMCID: PMC3590851 DOI: 10.1371/journal.pone.0058122] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 01/30/2013] [Indexed: 11/26/2022] Open
Abstract
Human herpesvirus 6A (HHV-6A) is a common virus with a worldwide distribution that has been associated with multiple sclerosis. Whether HHV-6A can replicate in dendritic cells (DC) and how the infection might modulate the functional properties of the cell are currently not well known and need further investigations. Here, we show that a non-productive infection of HHV-6A in DC leads to the up-regulation of HLA-ABC, via autocrine IFN-α signaling, as well as the up-regulation of HLA-DR and CD86. However, HHV-6A exposure reduces IL-8 secretion by DC and their capacity to stimulate allogenic T cell proliferation. The ability to suppress DC functions important for activation of innate and adaptive immune responses might be one successful strategy by which HHV-6A avoids the induction of appropriate host defense mechanisms, and thus facilitating persistent infection.
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Dagna L, Pritchett JC, Lusso P. Immunomodulation and immunosuppression by human herpesvirus 6A and 6B. Future Virol 2013; 8:273-287. [PMID: 24163703 PMCID: PMC3806647 DOI: 10.2217/fvl.13.7] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Like other members of the Herpesviridae family, human herpesvirus (HHV)-6A and HHV-6B have developed a wide variety of strategies to modulate or suppress host immune responses and, thereby, facilitate their own spread and persistence in vivo. Long considered two variants of the same virus, HHV-6A and HHV-6B have recently been reclassified as distinct viral species, although the established nomenclature has been maintained. In this review, we summarize the distinctive profiles of interaction of these two viruses with the human immune system. Both HHV-6A and HHV-6B display a tropism for CD4+ T lymphocytes, but they can also infect, in a productive or nonproductive fashion, other cells of the immune system. However, there are important differences regarding the ability of each virus to infect cytotoxic effector cells, as HHV-6A has been shown to productively infect several of these cells, whereas HHV-6B infects them inefficiently at best. In addition to direct cytopathic effects, both HHV-6A and HHV-6B can interfere with immunologic functions to varying degrees via cytokine modulation, including blockade of IL-12 production by professional antigen-presenting cells, modulation of cell-surface molecules essential for T-cell activation, and expression of viral chemokines and chemokine receptors. Some of these effects are related to signaling through and downregulation of the viral receptor, CD46, a key molecule linking innate and adaptive immune responses. Increasing attention has recently been focused on the importance of viral interactions with dendritic cells, which may serve both as targets of virus-mediated immunosuppression and as vehicles for viral transfer to CD4+ T cells. Our deepening knowledge of the mechanisms developed by HHV-6A and HHV-6B to evade immunologic control may lead to new strategies for the prevention and treatment of the diseases associated with these viruses. Moreover, elucidation of these viral mechanisms may uncover new avenues to therapeutically manipulate or modulate the immune system in immunologically mediated human diseases.
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Affiliation(s)
- Lorenzo Dagna
- Department of Medicine & Clinical Immunology, Vita-Salute San Raffaele University, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milano, Italy
| | | | - Paolo Lusso
- Viral Pathogenesis Section, Laboratory of Immunoregulation, NIAID, NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
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Martin LK, Schub A, Dillinger S, Moosmann A. Specific CD8⁺ T cells recognize human herpesvirus 6B. Eur J Immunol 2012; 42:2901-12. [PMID: 22886850 DOI: 10.1002/eji.201242439] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Revised: 06/23/2012] [Accepted: 08/01/2012] [Indexed: 11/08/2022]
Abstract
The importance of human herpesvirus 6 (HHV-6) species as human pathogens is increasingly appreciated. However, we do not understand how infection is controlled in healthy virus carriers, and why control fails in patients with disease. Other persistent viruses are under continuous surveillance by antigen-specific T cells, and specific T-cell repertoires have been well characterized for some of them. In contrast, knowledge on HHV-6-specific T-cell responses is limited, and missing for CD8(+) T cells. Here we identify CD8(+) T-cell responses to HHV-6B, the most widespread HHV-6 species, in healthy virus carriers. HHV-6B-specific CD8(+) T-cell lines and clones recognized HLA-A2-restricted peptides from the viral structural proteins U54 and U11, and displayed various antigen-specific antiviral effector functions. These CD8(+) T cells specifically recognized HHV-6B-infected primary CD4(+) T cells in an HLA-restricted manner, produced antiviral cytokines, and killed infected cells, whereas HHV-6A-infected cells were not recognized. Thus, HHV-6B-specific CD8(+) T cells are likely to contribute to control of infection, overcoming the immunomodulatory effects exerted by the virus. Potentially, HHV-6-associated disease could be addressed by active or passive immunotherapy that reconstitutes virus-specific CD8(+) T-cell responses.
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Affiliation(s)
- Larissa K Martin
- Clinical Cooperation Group Immunooncology, Department of Medicine III, Klinikum der Universität München and Department of Gene Vectors, Helmholtz Zentrum München, Munich, Germany
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Meyding-Lamadé U, Strank C. Herpesvirus infections of the central nervous system in immunocompromised patients. Ther Adv Neurol Disord 2012; 5:279-96. [PMID: 22973424 DOI: 10.1177/1756285612456234] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Human herpesviruses may cause infections of the central nervous system during primary infection or following reactivation from a latent state. Especially in immunosuppressed patients the infection can take a life-threatening course, and therefore early diagnosis of herpesvirus-associated neurological diseases should have high priority. Clinical presentation in these patients is usually without typical features, making diagnosis even more challenging. Therefore general broad testing for different herpesviruses in cerebrospinal fluid samples is highly recommended. In addition, determination of the virus DNA level in the cerebrospinal fluid by quantitative assays seems to be of high importance to determine prognosis. Moreover, it might help to differentiate between specific virus-associated disease and unspecific presence of virus in the cerebrospinal fluid, especially in immunocompromised patients. Polymerase chain reaction analysis of cerebrospinal fluid has revolutionized the diagnosis of nervous system viral infections, particularly those caused by human herpesviruses. This review summarizes the role human herpesviruses play in central nervous system infections in immunocompromised patients, with a focus on the clinical manifestation of encephalitis.
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Affiliation(s)
- Uta Meyding-Lamadé
- Head, Department of Neurology Krankenhaus Nordwest, Frankfurt/M. Germany
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Abstract
human herpesvirus 6 (HHV-6) is the major causative agent of exanthem subitum which is one of popular diseases in infant, and establishes latent infections in adults of more than 90%. Recently, the encephalitis caused by reactivated- HHV-6 has been shown in patients after transplantation. In addition, the relationship HHV-6 and drug-induced hypersensitivity syndrome has also been reported. human herpesvirus 7 (HHV-7) was isolated from the stimulated-peripheral blood lymphocytes of a healthy individual, and also causes exanthema subitum. Both viruses are related viruses which belong to betaherpesvirus subfamily, and replicate and produce progeny viruses in T cells.
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Tait AR, Straus SK. Overexpression and purification of U24 from human herpesvirus type-6 in E. coli: unconventional use of oxidizing environments with a maltose binding protein-hexahistine dual tag to enhance membrane protein yield. Microb Cell Fact 2011; 10:51. [PMID: 21714924 PMCID: PMC3155487 DOI: 10.1186/1475-2859-10-51] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 06/29/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Obtaining membrane proteins in sufficient quantity for biophysical study and biotechnological applications has been a difficult task. Use of the maltose binding protein/hexahistidine dual tag system with E.coli as an expression host is emerging as a high throughput method to enhance membrane protein yield, solubility, and purity, but fails to be effective for certain proteins. Optimizing the variables in this system to fine-tune for efficiency can ultimately be a daunting task. To identify factors critical to success in this expression system, we have selected to study U24, a novel membrane protein from Human Herpesvirus type-6 with potent immunosuppressive ability and a possible role in the pathogenesis of the disease multiple sclerosis. RESULTS We expressed full-length U24 as a C-terminal fusion to a maltose binding protein/hexahistidine tag and examined the effects of temperature, growth medium type, cell strain type, oxidizing vs. reducing conditions and periplasmic vs. cytoplasmic expression location. Temperature appeared to have the greatest effect on yield; at 37°C full-length protein was either poorly expressed (periplasm) or degraded (cytoplasm) whereas at 18°C, expression was improved especially in the periplasm of C41(DE3) cells and in the cytoplasm of oxidizing Δtrx/Δgor mutant strains, Origami 2 and SHuffle. Expression of the fusion protein in these strains were estimated to be 3.2, 5.3 and 4.3 times greater, respectively, compared to commonly-used BL21(DE3) cells. We found that U24 is isolated with an intramolecular disulfide bond under these conditions, and we probed whether this disulfide bond was critical to high yield expression of full-length protein. Expression analysis of a C21SC37S cysteine-free mutant U24 demonstrated that this disulfide was not critical for full-length protein expression, but it is more likely that strained metabolic conditions favour factors which promote protein expression. This hypothesis is supported by the fact that use of minimal media could enhance protein production compared to nutrient-rich LB media. CONCLUSIONS We have found optimal conditions for heterologous expression of U24 from Human Herpesvirus type-6 in E.coli and have demonstrated that milligram quantities of pure protein can be obtained. Strained metabolic conditions such as low temperature, minimal media and an oxidizing environment appeared essential for high-level, full-length protein production and this information may be useful for expressing other membrane proteins of interest.
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Affiliation(s)
- Andrew R Tait
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada
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Pattu V, Qu B, Marshall M, Becherer U, Junker C, Matti U, Schwarz EC, Krause E, Hoth M, Rettig J. Syntaxin7 is required for lytic granule release from cytotoxic T lymphocytes. Traffic 2011; 12:890-901. [PMID: 21438968 DOI: 10.1111/j.1600-0854.2011.01193.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
SNARE proteins are essential fusion mediators for many intracellular trafficking events. Here, we investigate the role of Syntaxin7 (Stx7) in the release of lytic granules from cytotoxic T lymphocytes (CTLs). We show that Stx7 is expressed in CTLs and is preferentially localized to the region of lytic granule release, the immunological synapse (IS). Interference of Stx7 function by expression of a dominant-negative Stx7 construct or by small interfering RNA leads to a dramatic reduction of CTL-mediated killing of target cells. Real-time visualization of individual lytic granules at the IS by evanescent wave microscopy reveals that lytic granules in Stx7-deprived CTLs not only fail to fuse with the plasma membrane but even fail to accumulate at the IS. Surprisingly, the accumulation defect is not caused by an overall reduction in lytic granule number, but by a defect in the trafficking of T cell receptors (TCRs) through endosomes. Subsequent high-resolution nanoscopy shows that Stx7 colocalizes with Rab7 on late endosomes. We conclude from these data that the accumulation of recycling TCRs at the IS is a SNARE-dependent process and that Stx7-mediated processing of recycling TCRs through endosomes is a prerequisite for the cytolytic function of CTLs.
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Affiliation(s)
- Varsha Pattu
- Institut für Physiologie, Universität des Saarlandes, Kirrberger Straße 8, Gebäude 59, 66421 Homburg, Saarland, Germany
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Flamand L, Komaroff AL, Arbuckle JH, Medveczky PG, Ablashi DV. Review, part 1: Human herpesvirus-6-basic biology, diagnostic testing, and antiviral efficacy. J Med Virol 2010; 82:1560-8. [PMID: 20648610 DOI: 10.1002/jmv.21839] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Louis Flamand
- Department of Microbiology, Infectious Diseases and Immunology, Faculty of Medicine, Laval University, Québec, Canada
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Sigalov AB. The SCHOOL of nature: IV. Learning from viruses. SELF/NONSELF 2010; 1:282-298. [PMID: 21487503 PMCID: PMC3062383 DOI: 10.4161/self.1.4.13279] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 08/04/2010] [Accepted: 08/05/2010] [Indexed: 02/05/2023]
Abstract
During the co-evolution of viruses and their hosts, the latter have equipped themselves with an elaborate immune system to defend themselves from the invading viruses. In order to establish a successful infection, replicate and persist in the host, viruses have evolved numerous strategies to counter and evade host antiviral immune responses as well as exploit them for productive viral replication. These strategies include those that modulate signaling mediated by cell surface receptors. Despite tremendous advancement in recent years, the exact molecular mechanisms underlying these critical points in viral pathogenesis remain unknown. In this work, based on a novel platform of receptor signaling, the Signaling Chain HOmoOLigomerization (SCHOOL) platform, I suggest specific mechanisms used by different viruses such as human immunodeficiency virus (HIV), cytomegalovirus (CMV), severe acute respiratory syndrome coronavirus, human herpesvirus 6 and others, to modulate receptor signaling. I also use the example of HIV and CMV to illustrate how two unrelated enveloped viruses use a similar SCHOOL mechanism to modulate the host immune response mediated by two functionally different receptors: T cell antigen receptor and natural killer cell receptor, NKp30. This suggests that it is very likely that similar general mechanisms can be or are used by other viral and possibly non-viral pathogens. Learning from viruses how to target cell surface receptors not only helps us understand viral strategies to escape from the host immune surveillance, but also provides novel avenues in rational drug design and the development of new therapies for immune disorders.
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Manolios N, Ali M, Bender V. T-cell antigen receptor (TCR) transmembrane peptides: A new paradigm for the treatment of autoimmune diseases. Cell Adh Migr 2010; 4:273-83. [PMID: 20431344 DOI: 10.4161/cam.4.2.11909] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cell surface membranes are generally considered as inert and hydrophobic providing a stable physical barrier that anchor proteins and maintain cellular homeostasis between the intra- and the extra-cellular environment. The integral proteins that transverse membranes do so once or multiple times and can function alone or as part of a larger complex. Far from being inert, there is a multiplicity of biophysical factors that drive protein-protein and protein-lipid interactions within membranes that are being increasingly recognised as very important for cellular function. Unravelling these "hot-spots" on the contact surface of transmembrane (TM) proteins and targeting peptides to these sites to interrupt the cohesive interaction between the proteins provides both an enormous challenge and a huge therapeutic potential that as yet remains unrecognized. Indeed, with biopharmaceutical research on the rise, TM peptides may prove a useful innovation. Using the T-cell antigen receptor (TCR) as a model system of multi-subunits interacting at the TM via electrostatic charges the potential for peptides as therapeutic agents to interfere with normal immune responses is discussed. The principles of such can be extended to other similar receptor systems including those involved in cancer or infection.
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Affiliation(s)
- Nicholas Manolios
- Department of Rheumatology, Westmead Hospital, Westmead, NSW, Australia.
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46
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Sigalov AB. New therapeutic strategies targeting transmembrane signal transduction in the immune system. Cell Adh Migr 2010; 4:255-67. [PMID: 20519929 DOI: 10.4161/cam.4.2.10746] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Single-chain receptors and multi-chain immune recognition receptors (SRs and MIRRs, respectively) represent families of structurally related but functionally different surface receptors expressed on different cells. In contrast to SRs, a distinctive and common structural characteristic of MIRR family members is that the extracellular recognition domains and intracellular signaling domains are located on separate subunits. How extracellular ligand binding triggers MIRRs and initiates intracellular signal transduction processes is not clear. A novel model of immune signaling, the Signaling Chain HOmoOLigomerization (SCHOOL) model, suggests that the homooligomerization of receptor intracellular signaling domains represents a necessary and sufficient condition for receptor triggering. In this review, I demonstrate striking similarities between a consensus model of SR signaling and the SCHOOL model of MIRR signaling and show how these models, together with the lessons learned from viral pathogenesis, provide a molecular basis for novel pharmacological approaches targeting inter- and intrareceptor transmembrane interactions as universal therapeutic targets for a diverse variety of immune and other disorders.
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Affiliation(s)
- Alexander B Sigalov
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, USA.
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47
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Abstract
Modulation of T-cell receptor expression and signaling is essential to the survival of many viruses. The U24 protein expressed by human herpesvirus 6A, a ubiquitous human pathogen, has been previously shown to downregulate the T-cell receptor. Here, we show that U24 also mediates cell surface downregulation of a canonical early endosomal recycling receptor, the transferrin receptor, indicating that this viral protein acts by blocking early endosomal recycling. We present evidence that U24 is a C-tail-anchored protein that is dependent for its function on TRC40/Asna-1, a component of a posttranslational membrane insertion pathway. Finally, we find that U24 proteins from other roseoloviruses have a similar genetic organization and a conserved function that is dependent on a proline-rich motif. Inhibition of a basic cellular process by U24 has interesting implications not only for the pathogenicity of roseoloviruses but also for our understanding of the biology of endosomal transport.
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Differential effect of human herpesvirus 6A on cell division and apoptosis among naive and central and effector memory CD4+ and CD8+ T-cell subsets. J Virol 2009; 83:5442-50. [PMID: 19297473 DOI: 10.1128/jvi.00106-09] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The immune responses of naive and different memory subsets of CD4(+) and CD8(+) T cells to human herpesvirus 6 (HHV-6) have not been previously investigated. We show that HHV-6A induces cell division, as measured by 5,6-carboxyfluorescein succinimidyl ester dye and flow cytometry, predominantly in two populations of effector memory CD4(+) and CD8(+) T cells (T(EM) and T(EMRA)); naïve (T(N)) and central memory (T(CM)) CD4(+) and CD8(+) T cells showed almost no cell division. In contrast, HHV-6A induced apoptosis primarily in T(N) and T(CM) CD4(+) and CD8(+) T cells, whereas T(EM) and T(EMRA) CD4(+) and CD8(+) T cells were resistant to HHV-6A-induced apoptosis. HHV-6A-induced apoptosis was associated with activation of caspase-8, caspase-9, and caspase-3, suggesting the involvement of death receptor and mitochondrial signaling pathways. In addition, HHV-6A induced secretion of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), IL-8, and gamma interferon by peripheral blood mononuclear cells; TNF-alpha secretion was observed exclusively from CCR7(+) (T(N) plus T(CM)) CD4(+) T cells. These data show that HHV-6 differentially influences the functions of naïve T cells and different subsets of memory CD4(+) and CD8(+) T cells, which in part may be due to differential susceptibility to HHV-6A-induced apoptosis.
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Phosphorylation of U24 from Human Herpes Virus type 6 (HHV-6) and its potential role in mimicking myelin basic protein (MBP) in multiple sclerosis. FEBS Lett 2008; 582:2685-8. [DOI: 10.1016/j.febslet.2008.06.050] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Revised: 06/10/2008] [Accepted: 06/11/2008] [Indexed: 01/14/2023]
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