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Quantifying the effectiveness of betaherpesvirus-vectored transmissible vaccines. Proc Natl Acad Sci U S A 2022; 119:2108610119. [PMID: 35046024 PMCID: PMC8794881 DOI: 10.1073/pnas.2108610119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2021] [Indexed: 11/26/2022] Open
Abstract
Spillover of infectious diseases from wildlife populations into humans is an increasing threat to human health and welfare. Current approaches to manage these emerging infectious diseases are largely reactive, leading to deadly and costly time lags between emergence and control. Here, we use mathematical models and data from previously published experimental and field studies to evaluate the scope for a more proactive approach based on transmissible vaccines that eliminates pathogens from wild animal populations before spillover can occur. Our models are focused on transmissible vaccines designed using herpes virus vectors and demonstrate that these vaccines—currently under development for several important human pathogens—may have the potential to rapidly control zoonotic pathogens within the reservoir hosts. Transmissible vaccines have the potential to revolutionize how zoonotic pathogens are controlled within wildlife reservoirs. A key challenge that must be overcome is identifying viral vectors that can rapidly spread immunity through a reservoir population. Because they are broadly distributed taxonomically, species specific, and stable to genetic manipulation, betaherpesviruses are leading candidates for use as transmissible vaccine vectors. Here we evaluate the likely effectiveness of betaherpesvirus-vectored transmissible vaccines by developing and parameterizing a mathematical model using data from captive and free-living mouse populations infected with murine cytomegalovirus (MCMV). Simulations of our parameterized model demonstrate rapid and effective control for a range of pathogens, with pathogen elimination frequently occurring within a year of vaccine introduction. Our results also suggest, however, that the effectiveness of transmissible vaccines may vary across reservoir populations and with respect to the specific vector strain used to construct the vaccine.
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Abstract
Memory inflation, as a term, has been used for 15 years now to describe the longitudinal development of stable, expanded CD8+ T memory pools with a distinct phenotype and functional profile which emerge in specific infection and vaccine settings. These settings have in common the persistence of antigen, especially cytomegalovirus infection but also more recently adenoviral vector vaccination. However, in contrast to chronic infections which lead to "exhaustion" the repeated antigen encounters experienced by CD8+ T cells lead to development of a robust T-cell population structure which maintains functionality and size. In this review, I will discuss how the ideas around this form of memory have evolved over time and some new models which can help explain how these populations are induced and sustained. These models are relevant to immunity against persistent viruses, to novel vaccine strategies and to concepts about aging.
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Affiliation(s)
- Paul Klenerman
- Peter Medawar Building for Pathogen Research and Translational Gastroenterology UnitUniversity of OxfordOxfordUK
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Schachtele SJ, Hu S, Sheng WS, Mutnal MB, Lokensgard JR. Glial cells suppress postencephalitic CD8+ T lymphocytes through PD-L1. Glia 2014; 62:1582-94. [PMID: 24890099 PMCID: PMC4141010 DOI: 10.1002/glia.22701] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 04/30/2014] [Accepted: 05/15/2014] [Indexed: 01/06/2023]
Abstract
Engagement of the programmed death (PD)−1 receptor on activated cells by its ligand (PD‐L1) is a mechanism for suppression of activated T‐lymphocytes. Microglia, the resident inflammatory cells of the brain, are important for pathogen detection and initiation of innate immunity, however, a novel role for these cells as immune regulators has also emerged. PD‐L1 on microglia has been shown to negatively regulate T‐cell activation in models of multiple sclerosis and acute viral encephalitis. In this study, we investigated the role of glial cell PD‐L1 in controlling encephalitogenic CD8+ T‐lymphocytes, which infiltrate the brain to manage viral infection, but remain to produce chronic neuroinflammation. Using a model of chronic neuroinflammation following murine cytomegalovirus (MCMV)‐induced encephalitis, we found that CD8+ T‐cells persisting within the brain expressed PD‐1. Conversely, activated microglia expressed PD‐L1. In vitro, primary murine microglia, which express low basal levels of PD‐L1, upregulated the co‐inhibitory ligand on IFN‐γ‐treatment. Blockade of the PD‐1: PD‐L1 pathway in microglial: CD8+ T‐cell co‐cultures increased T‐cell IFN‐γ and interleukin (IL)−2 production. We observed a similar phenomenon following blockade of this co‐inhibitory pathway in astrocyte: CD8+ T‐cell co‐cultures. Using ex vivo cultures of brain leukocytes, including microglia and CD8+ T‐cells, obtained from mice with MCMV‐induced chronic neuroinflammation, we found that neutralization of either PD‐1 or PD‐L1 increased IFN‐γ production from virus‐specific CD8+ T‐cells stimulated with MCMV IE1168–176 peptide. These data demonstrate that microglia and astrocytes control antiviral T‐cell responses and suggest a therapeutic potential of PD1: PD‐L1 modulation to manage the deleterious consequences of uncontrolled neuroinflammation. GLIA 2014;62:1582–1594 Microglia and astrocytes exert regulatory control over T‐cells during chronic neuroinflammation following viral brain infection. Post-encephalitic glial cells express PD‐L1 and suppress persistent CD8 T‐cells via the PD‐1: PD‐L1 inhibitory pathway.
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Affiliation(s)
- Scott J Schachtele
- Department of Medicine, Center for Infectious Diseases and Microbiology Translational Research, University of Minnesota, McGuire Translational Research Facility, Minneapolis, Minnesota
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Memory T cells persisting in the brain following MCMV infection induce long-term microglial activation via interferon-γ. J Neurovirol 2011; 17:424-37. [PMID: 21800103 DOI: 10.1007/s13365-011-0042-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 06/14/2011] [Accepted: 06/22/2011] [Indexed: 10/17/2022]
Abstract
Murine cytomegalovirus (MCMV) brain infection stimulates microglial cell-driven proinflammatory chemokine production which precedes the presence of brain-infiltrating systemic immune cells. Here, we show that in response to MCMV brain infection, antigen-specific CD8(+) T cells migrated into the brain and persisted as long-lived memory cells. The role of these persistent T cells in the brain is unclear because most of our understanding of antimicrobial T cell responses comes from analyses of lymphoid tissue. Strikingly, memory T cells isolated from the brain exhibited an effector phenotype and produced IFN-γ upon restimulation with viral peptide. Furthermore, we observed time-dependent and long-term activation of resident microglia, indicated by chronic MHC class II up-regulation and TNF-α production. The immune response in this immunologically restricted site persisted in the absence of active viral replication. Lymphocyte infiltrates were detected until 30 days post-infection (p.i.), with CD8(+) and CD4(+) T cells present at a 3:1 ratio, respectively. We then investigated the role of IFN-γ in chronic microglial activation by using IFN-γ-knockout (GKO) mice. At 30 days p.i., GKO mice demonstrated a similar phenotypic brain infiltrate when compared to wild-type mice (Wt), however, MHC class II expression on microglia isolated from these GKO mice was significantly lower compared to Wt animals. When IFN-γ producing CD8(+) T cells were reconstituted in GKO mice, MHC class II up-regulation on microglial cells was restored. Taken together, these results suggest that MCMV brain infection results in long-term persistence of antigen-specific CD8(+) T cells which produce IFN-γ and drive chronic microglial cell activation. This response was found to be dependent on IFN-γ production by viral Ag-specific T cells during the chronic phase of disease.
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López D, Jiménez M, García-Calvo M, Del Val M. Concerted antigen processing of a short viral antigen by human caspase-5 and -10. J Biol Chem 2011; 286:16910-3. [PMID: 21454616 DOI: 10.1074/jbc.m111.234658] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The generation of peptides presented by MHC class I molecules requires the proteolytic activity of the proteasome and/or other peptidases. The processing of a short vaccinia virus-encoded antigen can take place by a proteasome-independent pathway involving initiator caspase-5 and -10, which generate antigenic peptides recognized by CD8(+) T lymphocytes. In the present study, comparing single versus double enzyme digestions by mass spectrometry analysis, both qualitative and quantitative differences in the products obtained were identified. These in vitro data suggest that each enzyme can use the degradation products of the other as substrate for new cleavages, indicating concerted endoproteolytic activity of caspase-5 and -10.
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Affiliation(s)
- Daniel López
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, E-28220 Madrid, Spain.
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6
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Grewal JS, Pilgrim MJ, Grewal S, Kasman L, Werner P, Bruorton ME, London SD, London L. Salivary glands act as mucosal inductive sites via the formation of ectopic germinal centers after site-restricted MCMV infection. FASEB J 2011; 25:1680-96. [PMID: 21307334 DOI: 10.1096/fj.10-174656] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We investigated the hypothesis that salivary gland inoculation stimulates formation of ectopic germinal centers (GCs), transforming the gland into a mucosal inductive site. Intraglandular infection of mice with murine cytomegalovirus (MCMV; control: UV-inactivated MCMV) induces salivary gland ectopic follicles comprising cognate interactions between CD4(+) and B220(+) lymphocytes, IgM(+) and isotype-switched IgG(+) and IgA(+) B cells, antigen presenting cells, and follicular dendritic cells. B cells coexpressed the GC markers GCT (57%) and GL7 (52%), and bound the lectin peanut agglutinin. Lymphoid follicles were characterized by a 2- to 3-fold increase in mRNA for CXCL13 (lymphoid neogenesis), syndecan-1 (plasma cells), Blimp-1 (plasma cell development/differentiation), and a 2- to 6-fold increase for activation-induced cytidine deaminase, PAX5, and the nonexcised rearranged DNA of an IgA class-switch event, supporting somatic hypermutation and class-switch recombination within the salivary follicles. Intraglandular inoculation also provided protection against a systemic MCMV challenge, as evidenced by decreased viral titers (10(5) plaque-forming units to undetectable), and restoration of normal salivary flow rates from a 6-fold decrease. Therefore, these features suggest that the salivary gland participates in oral mucosal immunity via generation of ectopic GCs, which function as ectopic mucosal inductive sites.
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Affiliation(s)
- Jasvir S Grewal
- Department of Oral Biology and Pathology, School of Dental Medicine, Stony Brook University, Stony Brook, New York 11794, USA
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Thomas AC, Forster MR, Bickerstaff AA, Zimmerman PD, Wing BA, Trgovcich J, Bergdall VK, Klenerman P, Cook CH. Occult cytomegalovirus in vivarium-housed mice may influence transplant allograft acceptance. Transpl Immunol 2010; 23:86-91. [PMID: 20307665 PMCID: PMC2893234 DOI: 10.1016/j.trim.2010.03.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 03/14/2010] [Accepted: 03/14/2010] [Indexed: 01/19/2023]
Abstract
We have recently shown that latent murine cytomegalovirus (MCMV) can influence murine transplant allograft acceptance. During these studies we became aware that vivarium-housed control mice can acquire occult MCMV infection. The purpose of this investigation was to confirm occult MCMV transmission and determine the timing, vehicle, and possible consequences of transmission. Mice arriving from a commercial vendor were negative for MCMV both by commercial serologic testing and by our nested PCR. Mice housed in our vivarium became positive for MCMV DNA 30-60 days after arrival, but remained negative for MCMV by commercial serologic testing. To confirm MCMV we sequenced PCR products for several genes and showed >99% homology to MCMV. Further sequence analyses show that the occult MCMV is similar to a laboratory strain of MCMV, but the vehicle of transmission remains unclear. Control tissues from historical experiments with unexplained graft losses were evaluated for occult MCMV, and mice with unexplained allograft losses showed significantly higher incidence of occult MCMV than did allograft acceptors. Deliberate infection with very low titer MCMV confirmed that viral transmission can occur without measurable virus specific antibody or T-cell responses. These data suggest that vivarium-housed mice can develop occult MCMV that is missed by currently available commercial serologic testing, and that these infections may influence transplant allograft acceptance.
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Affiliation(s)
- A C Thomas
- Department of Surgery, The Ohio State University, Columbus, OH 43210, United States
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8
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López D, García-Calvo M, Smith GL, Del Val M. Caspases in virus-infected cells contribute to recognition by CD8+ T lymphocytes. THE JOURNAL OF IMMUNOLOGY 2010; 184:5193-9. [PMID: 20348426 DOI: 10.4049/jimmunol.1000050] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD8(+) cytotoxic T lymphocytes recognize infected cells in which MHC class I molecules present pathogen-derived peptides that have been processed mainly by proteasomes. Many infections induce a set of proteases, the caspases involved in apoptosis or inflammation. In this study, we report that processing and presentation of a short vaccinia virus-encoded Ag can take place also by a nonproteasomal pathway, which was blocked in infected cells with chemical inhibitors of caspases. By cleaving at noncanonical sites, at least two caspases generated antigenic peptides recognized by T lymphocytes. The sites and the peptidic products were partially overlapping but different to those used and produced by proteasomes in vitro. Antigenic natural peptides produced in infected cells by either pathway were quantitatively and qualitatively similar. Finally, coexpression of the natural vaccinia virus protein B13, which is an inhibitor of caspases and apoptosis, impaired Ag presentation by the caspase pathway in infected cells. These data support the hypothesis that numerous cellular proteolytic systems, including those induced during infection, such as caspases involved in apoptosis or in inflammation, contribute to the repertoire of presented peptides, thereby facilitating immunosurveillance.
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Affiliation(s)
- Daniel López
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Spain
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9
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Antiviral prevention of sepsis induced cytomegalovirus reactivation in immunocompetent mice. Antiviral Res 2009; 85:496-503. [PMID: 20004216 DOI: 10.1016/j.antiviral.2009.12.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 11/11/2009] [Accepted: 12/02/2009] [Indexed: 01/04/2023]
Abstract
INTRODUCTION Immunocompetent patients can reactivate latent cytomegalovirus (CMV) during critical illness and reactivation is associated with significantly worse outcomes. Prior to clinical trials in humans to prove causality, we sought to determine an optimal antiviral treatment strategy. METHODS Mice latently infected with murine CMV (MCMV) received a septic reactivation trigger and were randomized to receive one of four ganciclovir regimens or saline. Lungs were evaluated for viral transcriptional reactivation and fibrosis after each regimen. Influences of ganciclovir on early sepsis-induced pulmonary inflammation and T-cell activation were studied after sepsis induction. RESULTS All ganciclovir regimens reduced measurable MCMV transcriptional reactivation, and 10mg/day for 7 or 21 days was most effective. Lower dose (5mg/kg/day) or delayed therapy was associated with significant breakthrough reactivation. Higher doses of ganciclovir given early were associated with the lowest incidence of pulmonary fibrosis, and delay of therapy for 1 week was associated with significantly worse pulmonary fibrosis. Although bacterial sepsis induced activation of MCMV-specific pulmonary T-cells, this activation was not influenced by ganciclovir. CONCLUSION These results suggest that antiviral treatment trials in humans should use 10mg/kg/day ganciclovir administered as early as possible in at-risk patients to minimize reactivation events and associated pulmonary injury.
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Bantug GRB, Cekinovic D, Bradford R, Koontz T, Jonjic S, Britt WJ. CD8+ T lymphocytes control murine cytomegalovirus replication in the central nervous system of newborn animals. THE JOURNAL OF IMMUNOLOGY 2008; 181:2111-23. [PMID: 18641350 DOI: 10.4049/jimmunol.181.3.2111] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Human CMV infection of the neonatal CNS results in long-term neurologic sequelae. To define the pathogenesis of fetal human CMV CNS infections, we investigated mechanisms of virus clearance from the CNS of neonatal BALB/c mice infected with murine CMV (MCMV). Virus titers peaked in the CNS between postnatal days 10-14 and infectious virus was undetectable by postnatal day 21. Congruent with virus clearance was the recruitment of CD8(+) T cells into the CNS. Depletion of CD8(+) T cells resulted in death by postnatal day 15 in MCMV-infected animals and increased viral loads in the liver, spleen, and the CNS, suggesting an important role for these cells in the control of MCMV replication in the newborn brain. Examination of brain mononuclear cells revealed that CD8(+) T cell infiltrates expressed high levels of CD69, CD44, and CD49d. IE1(168)-specific CD8(+) T cells accumulated in the CNS and produced IFN-gamma and TNF-alpha but not IL-2 following peptide stimulation. Moreover, adoptive transfer of brain mononuclear cells resulted in decreased virus burden in immunodepleted MCMV-infected syngeneic mice. Depletion of the CD8(+) cell population following transfer eliminated control of virus replication. In summary, these results show that functionally mature virus-specific CD8(+) T cells are recruited to the CNS in mice infected with MCMV as neonates.
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Affiliation(s)
- Glenn R B Bantug
- Department of Microbiology, University of Alabama at Birmingham, Alabama 35294, USA
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11
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Brune W, Hengel H, Koszinowski UH. A mouse model for cytomegalovirus infection. ACTA ACUST UNITED AC 2008; Chapter 19:Unit 19.7. [PMID: 18432758 DOI: 10.1002/0471142735.im1907s43] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This unit describes procedures for infecting newborn and adult mice with murine cytomegalovirus (mCMV). Methods are included for propagating mCMV in cell cultures and for preparing a more virulent form of mCMV from salivary glands of infected mice. A plaque-forming cell (PFC) assay is provided for measuring mCMV titers of infected tissues or virus stocks. In addition, a method is described for preparing the murine embryonic fibroblasts used for propagating mCMV and for the PFC assay.
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Affiliation(s)
- W Brune
- University of Munich, Max von Pettenkofer Institute, Munich, Germany
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Pinto AK, Jamieson AM, Raulet DH, Hill AB. The role of NKG2D signaling in inhibition of cytotoxic T-lymphocyte lysis by the Murine cytomegalovirus immunoevasin m152/gp40. J Virol 2007; 81:12564-71. [PMID: 17855532 PMCID: PMC2169000 DOI: 10.1128/jvi.01328-07] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 08/31/2007] [Indexed: 12/26/2022] Open
Abstract
Three proteins encoded by murine cytomegalovirus (MCMV) -- gp34, encoded by m04 (m04/gp34), gp48, encoded by m06 (m06/gp48), and gp40, encoded by m152 (m152/gp40) -- act together to powerfully impact the ability of primed cytotoxic CD8 T lymphocytes (CTL) to kill virus-infected cells. Of these three, the impact of m152/gp40 on CTL lysis appears greater than would be expected based on its impact on cell surface major histocompatibility complex (MHC) class I. In addition to MHC class I, m152/gp40 also downregulates the RAE-1 family of NKG2D ligands, which can provide costimulation for CD8 T cells. We hypothesized that m152/gp40 may impact CTL lysis so profoundly because it inhibits both antigen presentation and NKG2D-mediated costimulation. We therefore tested the extent to which m152/gp40's ability to inhibit CTL lysis of MCMV-infected cells could be accounted for by its inhibition of NKG2D signaling. As was predictable from the results reported in the literature, NKG2D ligands were not detected by NKG2D tetramer staining of cells infected with wild-type MCMV, whereas those infected with MCMV lacking m152/gp40 displayed measurable levels of the NKG2D ligand. To determine whether NKG2D signaling contributed to the ability of CTL to lyse these cells, we used a blocking anti-NKG2D antibody. Blocking NKG2D signaling did affect the killing of MCMV-infected cells for some epitopes. However, for all epitopes, the impact of m152/gp40 on CTL lysis was much greater than the impact of inhibition of NKG2D signaling. We conclude that the downregulation of NKG2D ligands by MCMV makes only a small contribution to the impact of m152/gp40 on CTL lysis and only for a small subset of CTL.
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Affiliation(s)
- Amelia K Pinto
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97239, USA
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Tanaka K, Sawamura S, Satoh T, Kobayashi K, Noda S. Role of the indigenous microbiota in maintaining the virus-specific CD8 memory T cells in the lung of mice infected with murine cytomegalovirus. THE JOURNAL OF IMMUNOLOGY 2007; 178:5209-16. [PMID: 17404304 DOI: 10.4049/jimmunol.178.8.5209] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The potent role of indigenous microbiota in maintaining murine CMV (MCMV)-specific memory T cells, which were measured by multimer staining, was investigated using germfree (GF) mice. When the BALB/c mice bred under specific pathogen-free (SPF) conditions were i.p. infected with 0.2 LD(50) of MCMV, high frequencies of CD69(+)/CD44(+) MCMV-specific CD8 T cells were noted in the lungs even at 6-12 mo after infection (11.1 +/- 3.2 and 9.8 +/- 0.9%, respectively). In contrast, even though the viral load and expression levels of mRNA of such cytokines as IL-2, IL-7, IL-15, and IFN-gamma in the lungs of MCMV-infected GF mice were comparable to those of infected SPF mice, the frequencies of MCMV-specific CD8 T cells in the lungs of infected GF mice were kept lower than 1% at 6-12 mo after infection. In addition, the reconstitution of microbiota of MCMV-infected GF mice by orally administering a fecal suspension prepared from SPF mice restored the frequencies of both CD8(+)/multimer(+) and CD8(+)/multimer(-) T cells to levels similar to those found in SPF mice. These results suggested the indigenous microbiota to play a crucial role in the expansion and maintenance of viral-specific CD8 memory T cells, probably by cross-reactivity between the antigenic epitope of the MCMV-specific memory T cells and the variety of peptides derived from the members of the microbiota. Such cross-reactivity may thus be a major feature of those cells.
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Affiliation(s)
- Kazuo Tanaka
- Laboratory of Infectious Diseases, Tokai University School of Medicine, Isehara, Kanagawa, Japan.
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Scalzo AA, Corbett AJ, Rawlinson WD, Scott GM, Degli-Esposti MA. The interplay between host and viral factors in shaping the outcome of cytomegalovirus infection. Immunol Cell Biol 2006; 85:46-54. [PMID: 17146464 DOI: 10.1038/sj.icb.7100013] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cytomegalovirus (CMV) remains a major human pathogen causing significant morbidity and mortality in immunosuppressed or immunoimmature individuals. Although significant advances have been made in dissecting out certain features of the host response to human CMV (HCMV) infection, the strict species specificity of CMVs means that most aspects of antiviral immunity are best assessed in animal models. The mouse model of murine CMV (MCMV) infection is an important tool for analysis of in vivo features of host-virus interactions and responses to antiviral drugs that are difficult to assess in humans. Important studies of the contribution of host resistance genes to infection outcome, interplays between innate and adaptive host immune responses, the contribution of virus immune evasion genes and genetic variation in these genes to the establishment of persistence and in vivo studies of resistance to antiviral drugs have benefited from the well-developed MCMV model. In this review, we discuss recent advances in the immunobiology of host-CMV interactions that provide intriguing insights into the complex interplay between host and virus that ultimately facilitates viral persistence. We also discuss recent studies of genetic responses to antiviral therapy, particularly changes in DNA polymerase and protein kinase genes of MCMV and HCMV.
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Affiliation(s)
- Anthony A Scalzo
- Immunology and Virology Program, Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, Western Australia, Australia.
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15
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Pinto AK, Munks MW, Koszinowski UH, Hill AB. Coordinated function of murine cytomegalovirus genes completely inhibits CTL lysis. THE JOURNAL OF IMMUNOLOGY 2006; 177:3225-34. [PMID: 16920962 DOI: 10.4049/jimmunol.177.5.3225] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Murine CMV (MCMV) encodes three viral genes that interfere with Ag presentation (VIPRs) to CD8 T cells, m04, m06, and m152. Because the functional impact of these genes during normal infection of C57BL/6 mice is surprisingly modest, we wanted to determine whether the VIPRs are equally effective against the entire spectrum of H-2(b)-restricted CD8 T cell epitopes. We also wanted to understand how the VIPRs interact at a functional level. To address these questions, we used a panel of MCMV mutants lacking each VIPR in all possible combinations, and CTL specific for 15 H-2(b)-restricted MCMV epitopes. Only expression of all three MCMV VIPRs completely inhibited killing by CTL specific for all 15 epitopes, but removal of any one VIPR enabled lysis by at least some CTL. The dominant interaction between the VIPRs was cooperation: m06 increased the inhibition of lysis achieved by either m152 or m04. However, for 1 of 15 epitopes m04 functionally antagonized m152. There was little differential impact of any of the VIPRs on K(b) vs D(b), but a surprising degree of differential impact of the three VIPRs for different epitopes. These epitope-specific differences did not correlate with functional avidity, or with timing of VIPR expression in relation to Ag expression in the virus replication cycle. Although questions remain about the molecular mechanism and in vivo role of these genes, we conclude that the coordinated function of MCMV's three VIPRs results in a powerful inhibition of lysis of infected cells by CD8 T cells.
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Affiliation(s)
- Amelia K Pinto
- Oregon Health and Science University, Molecular Microbiology and Immunology, Portland, OR 97239, USA
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16
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López D, Calero O, Jiménez M, García-Calvo M, Del Val M. Antigen processing of a short viral antigen by proteasomes. J Biol Chem 2006; 281:30315-8. [PMID: 16861221 DOI: 10.1074/jbc.m605973200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mass spectrometry (MS)-based methods coupled to reverse phase chromatography separation are a useful technology to analyze complex peptide pools that are comprised of different peptides with unrelated sequences. In antigen presentation, proteasomes generate a set of short peptides that are closely related and overlapping and in some instances may even have identical retention times and identical masses. In these situations, micro-liquid chromatography-MS/MS focused on each theoretical parent ion followed by manual interpretation optimizes the identification of generated peptides. The results suggest that the degradation of short antigens by the proteasome occurs by sequential cleavage.
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Affiliation(s)
- Daniel López
- Unidad de Proteómica, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Madrid, Spain.
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17
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Gorman S, Harvey NL, Moro D, Lloyd ML, Voigt V, Smith LM, Lawson MA, Shellam GR. Mixed infection with multiple strains of murine cytomegalovirus occurs following simultaneous or sequential infection of immunocompetent mice. J Gen Virol 2006; 87:1123-1132. [PMID: 16603512 DOI: 10.1099/vir.0.81583-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
As with human cytomegalovirus (HCMV) infection of humans, murine CMV (MCMV) infection is widespread in its natural host, the house mouse Mus domesticus, and may consist of mixed infection with different CMV isolates. The incidence and mechanisms by which mixed infection occurs in free-living mice are unknown. This study used two approaches to determine whether mixed infection with MCMV could be established in laboratory mice. The first utilized two naturally occurring MCMV strains, N1 and G4, into which the lacZ gene was inserted by homologous recombination. The lacZ gene was used to track recombinant and parental viruses in simultaneously coinfected mice. In the second approach, a real-time quantitative PCR (qPCR) assay was used to detect viral immediate-early 1 (ie1) gene sequences in mice successively coinfected with G4 and then with the K181 MCMV strain. In both systems, mixed infection was detected in the salivary glands and lungs of experimentally infected mice. MCMV-specific antibody in sera and G4 IE1-specific cytotoxic lymphocyte responses in the spleens of twice-infected mice did not prevent reinfection. Finally, the prevalence of mixed infection in free-living mice trapped in four Australian locations was investigated using real-time qPCR to detect ie1 DNA sequences of N1, G4 and K181. Mixed infection with MCMVs containing the G4 and K181 ie1 sequences was detected in the salivary glands of 34·2 % of trapped mice. The observations that mixed infections are common in free-living M. domesticus and are acquired by immunocompetent mice through simultaneous or successive infections are important for vaccine development.
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Affiliation(s)
- Shelley Gorman
- Discipline of Microbiology, School of Biomedical and Chemical Sciences, M502, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Nicole L Harvey
- Discipline of Microbiology, School of Biomedical and Chemical Sciences, M502, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Dorian Moro
- School of Natural Sciences, Edith Cowan University, Joondalup, WA 6027, Australia
| | - Megan L Lloyd
- Discipline of Microbiology, School of Biomedical and Chemical Sciences, M502, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Valentina Voigt
- Centre for Experimental Immunology, Lions Eye Institute, 2 Verdun Street, Nedlands, WA 6009, Australia
- Discipline of Microbiology, School of Biomedical and Chemical Sciences, M502, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Lee M Smith
- Discipline of Microbiology, School of Biomedical and Chemical Sciences, M502, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Malcolm A Lawson
- Discipline of Microbiology, School of Biomedical and Chemical Sciences, M502, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Geoffrey R Shellam
- Discipline of Microbiology, School of Biomedical and Chemical Sciences, M502, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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18
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Zimmermann N, Rötzschke O, Falk K, Rognan D, Folkers G, Rammensee HG, Jung G. Moleküldynamiksimulation für ein allelspezifisches virales Nonapeptid aus dem Influenza-Matrix-protein in der Bindungstasche eines menschlichen MHC-Klasse-I-Proteins. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.19921040741] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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19
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Samino Y, López D, Guil S, Saveanu L, van Endert PM, Del Val M. A long N-terminal-extended nested set of abundant and antigenic major histocompatibility complex class I natural ligands from HIV envelope protein. J Biol Chem 2006; 281:6358-65. [PMID: 16407287 DOI: 10.1074/jbc.m512263200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Viral antigens complexed with major histocompatibility complex (MHC) class I molecules are recognized by cytotoxic T lymphocytes on infected cells. Assays with synthetic peptides identify optimal MHC class I ligands often used for vaccines. However, when natural peptides are analyzed, more complex mixtures including long peptides bulging in the middle of the binding site or with carboxyl extensions are found, reflecting lack of exposure to carboxypeptidases in the antigen processing pathway. In contrast, precursor peptides are exposed to extensive cytosolic aminopeptidase activity, and fewer than 1% survive, only to be further trimmed in the endoplasmic reticulum. We show here a striking example of a nested set of at least three highly antigenic and similarly abundant natural MHC class I ligands, 15, 10, and 9 amino acids in length, derived from a single human immunodeficiency virus gp160 epitope. Antigen processing, thus, gives rise to a rich pool of possible ligands from which MHC class I molecules can choose. The natural peptide set includes a 15-residue-long peptide with unprecedented 6 N-terminal residues that most likely extend out of the MHC class I binding groove. This 15-mer is the longest natural peptide known recognized by cytotoxic T lymphocytes and is surprisingly protected from aminopeptidase trimming in living cells.
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Affiliation(s)
- Yolanda Samino
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Madrid, Spain
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20
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Sierro S, Rothkopf R, Klenerman P. Evolution of diverse antiviral CD8+ T cell populations after murine cytomegalovirus infection. Eur J Immunol 2005; 35:1113-23. [PMID: 15756645 DOI: 10.1002/eji.200425534] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Cytomegalovirus (CMV) is a major human pathogen normally controlled by cellular immune responses. The infection can be modeled in the mouse using murine CMV (MCMV). During the latent phase of infection, two different patterns of CD8(+) T cell responses have been observed: some specificities show increasing frequencies over time ("memory inflation"), while others, which are present acutely, are barely detectable at later time points. This distinction is independent of initial immunodominance. We analyzed the extent to which such responses differ functionally and tracked both their population distribution and their evolution over time. We observed two clear patterns of memory development that diverged early after infection. Acutely, CD8(+) T cells directed against all epitopes showed similar activation, phenotype and distribution. Thereafter, one set of responses ("inflationary") increased in frequency over time, was found in high numbers in non-lymphoid organs and was associated with an activated (CD28(low) CD27(low)CD122(low)) phenotype. In contrast, CD8(+) T cells responses specific for other MCMV epitopes ("non-inflationary") showed a slow reversion to a classical "central" memory phenotype without enrichment in non-lymphoid organs. A simple model to describe the equilibrium state in MCMV is presented, which may point to previously unexplored antiviral populations present after human CMV infection.
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Affiliation(s)
- Sophie Sierro
- The Peter Medawar Building for Pathogen Research, Oxford, UK.
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21
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Johnstone C, de León P, Medina F, Melero JA, García-Barreno B, Val MD. Shifting immunodominance pattern of two cytotoxic T-lymphocyte epitopes in the F glycoprotein of the Long strain of respiratory syncytial virus. J Gen Virol 2004; 85:3229-3238. [PMID: 15483236 DOI: 10.1099/vir.0.80219-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Human respiratory syncytial virus (RSV) is a major cause of respiratory infection in children and in the elderly. The RSV fusion (F) glycoprotein has long been recognized as a vaccine candidate as it elicits cytotoxic T-lymphocyte (CTL) and antibody responses. Two murine H-2K(d)-restricted CTL epitopes (F85-93 and F92-106) are known in the F protein of the A2 strain of RSV. F-specific CTL lines using BCH4 fibroblasts that are persistently infected with the Long strain of human RSV as stimulators were generated, and it was found that in this strain only the F85-93 epitope is conserved. Motif based epitope prediction programs and an F2 chain deleted F protein encoded in a recombinant vaccinia virus enabled identification of a new epitope in the Long strain, F249-258, which is presented by K(d) as a 9-mer (TYMLTNSEL) or a 10-mer (TYMLTNSELL) peptide. The results suggest that the 10-mer might be a naturally processed endogenous K(d) ligand. The CD8(+) T-lymphocyte responses to epitopes F85-93 and F249-258 present in the F protein of RSV Long were found to be strongly skewed to F85-93 in in vitro multispecific CTL lines and in vivo during a secondary response to a recombinant vaccinia virus that expresses the entire F protein. However, no hierarchy in CD8(+) T-lymphocyte responses to F85-93 and F249-258 epitopes was observed in vivo during a primary response.
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Affiliation(s)
- Carolina Johnstone
- Unidade de Inmunología Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Pozuelo km 2, E-28220 Majadahonda (Madrid), Spain
| | - Patricia de León
- Unidade de Inmunología Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Pozuelo km 2, E-28220 Majadahonda (Madrid), Spain
| | - Francisco Medina
- Unidade de Inmunología Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Pozuelo km 2, E-28220 Majadahonda (Madrid), Spain
| | - José A Melero
- Unidade de Biología Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Pozuelo km 2, E-28220 Majadahonda (Madrid), Spain
| | - Blanca García-Barreno
- Unidade de Biología Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Pozuelo km 2, E-28220 Majadahonda (Madrid), Spain
| | - Margarita Del Val
- Unidade de Inmunología Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Pozuelo km 2, E-28220 Majadahonda (Madrid), Spain
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22
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Pelte C, Cherepnev G, Wang Y, Schoenemann C, Volk HD, Kern F. Random screening of proteins for HLA-A*0201-binding nine-amino acid peptides is not sufficient for identifying CD8 T cell epitopes recognized in the context of HLA-A*0201. THE JOURNAL OF IMMUNOLOGY 2004; 172:6783-9. [PMID: 15153496 DOI: 10.4049/jimmunol.172.11.6783] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
HLA-A2 is the most frequent HLA molecule in Caucasians with HLA-A*0201 representing the most frequent allele; it was also the first human HLA allele for which peptide binding prediction was developed. The Bioinformatics and Molecular Analysis Section of the National Institutes of Health (BIMAS) and the University of Tübingen (Syfpeithi) provide the most popular prediction algorithms of peptide/MHC interaction on the World Wide Web. To test these predictions, HLA-A*0201-binding nine-amino acid peptides were searched by both algorithms in 19 structural CMV proteins. According to Syfpeithi, the top 2% of predicted peptides should contain the naturally presented epitopes in 80% of predictions (www.syfpeithi.de). Because of the high number of predicted peptides, the analysis was limited to 10 randomly chosen proteins. The top 2% of peptides predicted by both algorithms were synthesized corresponding to 261 peptides in total. PBMC from 10 HLA-A*0201-positive and CMV-seropositive healthy blood donors were tested by ex vivo stimulation with all 261 peptides using crossover peptide pools. IFN-gamma production in T cells measured by CFC was used as readout. However, only one peptide was found to be stimulating in one single donor. As a result of this work, we report a potential new T cell target protein, one previously unknown CD8-T cell-stimulating peptide, and an extensive list of CMV-derived potentially strong HLA-A*0201-binding peptides that are not recognized by T cells of HLA-A*0201-positive CMV-seropositive donors. We conclude that MHC/peptide binding predictions are helpful for locating epitopes in known target proteins but not necessarily for screening epitopes in proteins not known to be T cell targets.
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Affiliation(s)
- Christian Pelte
- Institut für Medizinische Immunologie der Charité, Humboldt-Universität zu Berlin (Charité), Campus Charité Mitte, Berlin, Germany
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23
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Zimmermann N, Rötzschke O, Falk K, Rognan D, Folkers G, Rammensee HG, Jung G. Molecular Modeling of the Class I Human Histocompatibility Molecule HLA-A2 Presenting an Allele-Specific Nonapeptide from Influenza Matrix Protein. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/anie.199208861] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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24
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Samino Y, Lopez D, Guil S, de León P, Del Val M. An endogenous HIV envelope-derived peptide without the terminal NH3+ group anchor is physiologically presented by major histocompatibility complex class I molecules. J Biol Chem 2003; 279:1151-60. [PMID: 14583622 DOI: 10.1074/jbc.m305343200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytotoxic T lymphocytes (CTL) recognize viral peptidic antigens presented by major histocompatibility complex (MHC) class I molecules on the surface of infected cells. The CTL response is critical in clearance and prevention of HIV infection. Yet, there are no descriptions of physiological peptides derived from the viral envelope protein. In the few reports on endogenous MHC class I viral peptidic ligands from HIV internal proteins, definitive positive identification by mass spectrometry is lacking. The HIV-1 envelope glycoprotein gp160 induces a strong specific CTL response restricted by several human and murine MHC class I molecules, including H-2Dd. Previous analyses showed that this response can be optimally mimicked with the synthetic decameric peptide 318RGPGRAFVTI327. We aim to identify the endogenous natural peptides mediating the response to this epitope. Our data indicate the presence of, at least, two peptidic species of different length and sharing the same antigenic core, which are associated with the Dd presenting molecule in infected cells. One species is at least, probably, the optimal decapeptide. The second species, identified by mass spectrometry for the first time in HIV, is, unexpectedly, a nonamer, which lacks the correctly positioned N-terminal group to bind to Dd. And yet, it is present in similar amounts and, notably, is equally antigenic. Thus, the physiological set of HIV-derived MHC class I ligands is richer and different than expected from studies with synthetic peptides. This may help raise the plasticity and thus the effectiveness of the immune response against the viral infection. These data have implications for HIV vaccine development.
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Affiliation(s)
- Yolanda Samino
- Centro Nacional de Microbiología. Instituto de Salud Carlos III, E-28220 Madrid, Spain
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25
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Kamm C, Skoberne M, Geginat G. CD8 T cell immunome analysis of Listeria monocytogenes. FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY 2003; 35:235-42. [PMID: 12648842 DOI: 10.1016/s0928-8244(02)00450-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The identification of T cell epitopes is crucial for the understanding of the host response during infections with pathogenic microorganisms. Generally, the identification of relevant T cell responses is based on the analysis of T cell lines propagated in vitro. We used an ex vivo approach for the analysis of the CD8 T cell response against Listeria monocytogenes that is based upon the fractionation of naturally processed antigenic peptides and subsequent analysis with T cells in an enzyme-linked immunospot (ELISPOT) assay. Our data indicate that the direct ex vivo ELISPOT analysis of peptides extracted from infected tissues represents a versatile and potent test system for the analysis of the CD8 T cell immunome of microorganisms that furthermore requires neither the knowledge of the microbial genome nor of the specificity of responding T cells.
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Affiliation(s)
- Christian Kamm
- Institut für Medizinische Mikrobiologie und Hygiene, Fakultät für Klinische Medizin Mannheim der Universität Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
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26
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Morley PJ, Ertl PF, Sweet C. High-frequency interferon-gamma-secreting splenocytes specific for murine cytomegalovirus immediate-early-1 (IE-1) peptide 168YPHFMPTNL176 are insufficient to provide complete protection from viral challenge. J Med Virol 2003; 69:240-50. [PMID: 12683414 DOI: 10.1002/jmv.10272] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Infection of Balb/c mice with murine cytomegalovirus (MCMV) has been used extensively as a model system with which to study host mechanisms of immunity to cytomegaloviruses. In this model, the cytotoxic T-lymphocyte (CTL) response crucial for clearing infected cells is dominated by CTLs specific for the MCMV nonapeptide 168YPHFMPTNL176 encoded by the immediate-early 1 (IE-1) gene. The intradermal injection of plasmid pcDNA89 encoding IE-1 has been shown to offer some protection from viral challenge. In the present studies, the protective efficacy of immunisation with pcDNA89 given by intradermal injection was compared with particle-mediated DNA delivery (PMDD) and contrasted with that induced by injection with the K181 MCMV strain and with temperature-sensitive mutants (tsm) derived from the K181 strain. Modest protection was afforded by pcDNA89 immunisation given by PMDD, but none was observed after intradermal injection. PMDD immunisation induced a frequency of 168YPHFMPTNL176-specific interferon-gamma (IFN-gamma)-secreting splenocytes, which was equivalent to that after K181 infection and significantly higher than tsm immunisation. Whereas tsm-immunised mice were completely protected from MCMV challenge, PMDD-immunised mice were only weakly protected. Tsm immunisation protected mice completely against challenge with natural isolates having sequence variation in the IE-1 nonapeptide, while PMDD-immunised mice were weakly protected from isolates encoding 168YPHFMPTNL176 and were not protected against isolates encoding 168YPHFMPPSL176 or 168YLDFMPPNL176. Thus, while IE-1-specific IFN-gamma-secreting splenocytes do contribute to immunity from MCMV challenge, their presence in isolation is insufficient to provide complete protection and they may not be involved in the protection observed against MCMV isolates having IE-1 sequence variation.
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Affiliation(s)
- Peter J Morley
- Department of UK Virology, GlaxoSmithKline Research and Development Ltd, Stevenage, Hertfordshire, United Kingdom.
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27
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Reddehase MJ. Antigens and immunoevasins: opponents in cytomegalovirus immune surveillance. Nat Rev Immunol 2002; 2:831-44. [PMID: 12415307 DOI: 10.1038/nri932] [Citation(s) in RCA: 239] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
CD8+ T cells are the main effector cells for the immune control of cytomegaloviruses. To subvert this control, human and mouse cytomegaloviruses each encode a set of immune-evasion proteins, referred to here as immunoevasins, which interfere specifically with the MHC class I pathway of antigen processing and presentation. Although the concerted action of immunoevasins prevents the presentation of certain viral peptides, other viral peptides escape this blockade conditionally or constitutively and thereby provide the molecular basis of immune surveillance by CD8+ T cells. The definition of viral antigenic peptides that are presented despite the presence of immunoevasins adds a further dimension to the prediction of protective epitopes for use in vaccines.
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Affiliation(s)
- Matthias J Reddehase
- Institute for Virology, Johannes Gutenberg University, Hochhaus am Augustusplatz, 55101 Mainz, Germany.
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28
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Del-Val M, López D. Multiple proteases process viral antigens for presentation by MHC class I molecules to CD8(+) T lymphocytes. Mol Immunol 2002; 39:235-47. [PMID: 12200053 DOI: 10.1016/s0161-5890(02)00104-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Recognition by CD8(+) cytotoxic T lymphocytes of any intracellular viral protein requires its initial cytosolic proteolytic processing, the translocation of processed peptides to the endoplasmic reticulum via the transporters associated with antigen processing, and their binding to nascent major histocompatibility complex (MHC) class I molecules that then present the antigenic peptides at the infected cell surface. From initial assumptions that the multicatalytic and ubiquitous proteasome is the only protease capable of fully generating peptide ligands for MHC class I molecules, the last few years have seen the identification of a number of alternative proteases that contribute to endogenous antigen processing. Trimming by non-proteasomal proteases of precursor peptides produced by proteasomes is now a well-established fact. In addition, proteases that can process antigens in a fully proteasome-independent fashion have also been identified. The final level of presentation of many viral epitopes is probably the result of interplay between different proteolytic activities. This expands the number of tissues and physiological and pathological situations compatible with antigen presentation, as well as the universe of pathogen-derived sequences available for recognition by CD8(+) T lymphocytes.
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Affiliation(s)
- Margarita Del-Val
- Centro Nacional de Microbiologi;a, Instituto de Salud Carlos III, Ctra. Pozuelo, Km 2, E-28220 Majadahonda, Madrid, Spain.
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29
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Gold MC, Munks MW, Wagner M, Koszinowski UH, Hill AB, Fling SP. The murine cytomegalovirus immunomodulatory gene m152 prevents recognition of infected cells by M45-specific CTL but does not alter the immunodominance of the M45-specific CD8 T cell response in vivo. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:359-65. [PMID: 12077265 DOI: 10.4049/jimmunol.169.1.359] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although in vitro studies have shown that herpesviruses, including murine CMV (MCMV), encode genes that interfere with the MHC class I pathway, their effects on the CTL response in vivo is unclear. We identified a D(b)-restricted CTL epitope from MCMV M45 by screening an MCMV genomic library using CTL clones isolated from mice infected with MCMV lacking m152. Because m152 severely inhibits CTL recognition of M45 in vitro, we questioned whether an M45-specific response would be generated in mice infected with wild-type MCMV expressing m152. Mice infected with wild-type MCMV or MCMVDelta(m)152 made similar responses to the M45 Ag. Moreover, we saw no skewing of the proportion of M45-specific CD8 T cells within the total MCMV-specific response after infection with MCMV with m152. Despite the profound effect m152 has on presentation of M45 in vitro, it does not affect the immunodominance of M45 in the CTL response in vivo.
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MESH Headings
- Adjuvants, Immunologic/genetics
- Adjuvants, Immunologic/physiology
- Animals
- Antigen Presentation/genetics
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/virology
- Cell Line
- Cell Line, Transformed
- Cell Separation
- Clone Cells
- Epitopes, T-Lymphocyte/immunology
- Female
- H-2 Antigens/immunology
- Herpesviridae Infections/immunology
- Histocompatibility Antigen H-2D
- Immediate-Early Proteins/genetics
- Immediate-Early Proteins/immunology
- Immunodominant Epitopes/immunology
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred C57BL
- Muromegalovirus/genetics
- Muromegalovirus/immunology
- Muromegalovirus/physiology
- Peptide Fragments/immunology
- Peptide Fragments/metabolism
- Ribonucleotide Reductases/immunology
- Ribonucleotide Reductases/metabolism
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
- T-Lymphocytes, Cytotoxic/virology
- Viral Proteins
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Affiliation(s)
- Marielle C Gold
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97201, USA
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30
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Holtappels R, Grzimek NKA, Simon CO, Thomas D, Dreis D, Reddehase MJ. Processing and presentation of murine cytomegalovirus pORFm164-derived peptide in fibroblasts in the face of all viral immunosubversive early gene functions. J Virol 2002; 76:6044-53. [PMID: 12021337 PMCID: PMC136202 DOI: 10.1128/jvi.76.12.6044-6053.2002] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CD8 T cells are the principal effector cells in the resolution of acute murine cytomegalovirus (mCMV) infection in host organs. This undoubted antiviral and protective in vivo function of CD8 T cells appeared to be inconsistent with immunosubversive strategies of the virus effected by early (E)-phase genes m04, m06, and m152. The so-called immune evasion proteins gp34, gp48, and gp37/40, respectively, were found to interfere with peptide presentation at different steps in the major histocompatibility complex (MHC) class I pathway of antigen processing and presentation in fibroblasts. Accordingly, they were proposed to prevent recognition and lysis of infected fibroblasts by cytolytic T lymphocytes (CTL) during the E phase of viral gene expression. We document here that the previously identified MHC class I D(d)-restricted antigenic peptide (257)AGPPRYSRI(265) encoded by gene m164 is processed as well as presented for recognition by m164-specific CTL during the E and late phases of viral replication in the very same cells in which the immunosubversive viral proteins are effectual in preventing the presentation of processed immediate-early 1 (m123-exon 4) peptide (168)YPHFMPTNL(176). Thus, while immunosubversion is a reality, these mechanisms are apparently not as efficient as the term immune evasion implies. The pORFm164-derived peptide is the first noted peptide that constitutively escapes the immunosubversive viral functions. The most important consequence is that even the concerted action of all immunosubversive E-phase proteins eventually fails to prevent immune recognition in the E phase. The bottom-line message is that there exists no immune evasion of mCMV in fibroblasts.
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Affiliation(s)
- Rafaela Holtappels
- Institute for Virology, Johannes Gutenberg University, 55101 Mainz, Germany
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31
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Abstract
The cause of alcoholic liver disease (ALD) is multifactorial and poorly understood. It is clear that alcohol alone is not responsible for most of the changes associated with ALD and that cofactors are involved in initiation and production of ALD. One cofactor that has received a great deal of attention recently is the concomitant infection with hepatitis C virus (HCV) and alcohol abuse. The interactive effects of HCV and alcohol abuse are still unclear, but apparently they are the result of an inability of the immune system to control the viral infection and exaggerated hepatocyte damage mediated by either the cells of the inflammatory response or factors produced by the inflammatory cells. This review will focus on one aspect of the possible pathogenic effects associated with alcohol abuse and HCV infection: the possible role of the immune system, notably the cytotoxic T lymphocyte (CTL) response. It is clear that the development of a CTL response is critical for the control of HCV infections, and it is also likely that this response is involved in liver damage. In this review, the evidence that shows the importance of the CD8(+) CTL in viral clearance and the role for pathogenesis will be presented. Findings obtained from animal studies that support the suggestion that activated CD8(+) CTLs can induce liver damage will be presented, as will results of recent studies from my laboratory that provide evidence for an effect of alcohol to enhance the liver damage mediated by activated CD8(+) T cells.
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Affiliation(s)
- Thomas R Jerrells
- Department of Pathology and Microbiology, University of Nebraska Medical Center and Omaha VA Medical Center, Omaha, NE 68105, USA.
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32
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Lyman MA, Lee HG, Kang BS, Kang HK, Kim BS. Capsid-specific cytotoxic T lymphocytes recognize three distinct H-2D(b)-restricted regions of the BeAn strain of Theiler's virus and exhibit different cytokine profiles. J Virol 2002; 76:3125-34. [PMID: 11884537 PMCID: PMC136020 DOI: 10.1128/jvi.76.7.3125-3134.2002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The role of virus-specific cytotoxic T lymphocytes (CTL) in Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease, a viral model for multiple sclerosis, is not yet clear. To investigate the specificity and function of CTL generated in response to TMEV infection, we generated a panel of overlapping 20-mer peptides encompassing the entire capsid and leader protein region of the BeAn strain of TMEV. Binding of these peptides to H-2K(b) and H-2D(b) class I molecules of resistant mice was assessed using RMA-S cells. Several peptides displayed significant binding to H-2K(b), H-2D(b), or both. However, infiltrating cytotoxic T cells in the central nervous system of virus-infected mice preferentially lysed target cells pulsed with VP2(111-130/121-140) or VP2(121-130), a previously defined CTL epitope shared by the DA strain of TMEV and other closely related cardioviruses. In addition, at a high effector-to-target cell ratio, two additional peptides (VP2(161-180) and VP3(101-120)) sensitized target cells for cytolysis by infiltrating T cells or splenic T cells from virus-infected mice. The minimal epitopes within these peptides were defined as VP2(165-173) and VP3(110-120). Based on cytokine profiles, CTL specific for these subdominant epitopes are Tc2, in contrast to CTL for the immunodominant epitope, which are of the Tc1 type. Interestingly, CTL function towards both of these subdominant epitopes is restricted by the H-2D molecule, despite the fact that these epitopes bind both H-2K and H-2D molecules. This skewing toward an H-2D(b)-restricted response may confer resistance to TMEV-induced demyelinating disease, which is known to be associated with the H-2D genetic locus.
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Affiliation(s)
- Michael A Lyman
- Department of Microbiology-Immunology and Institute of Neuroscience, Northwestern University Medical School, Chicago, Illinois 60611, USA
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33
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López D, Samino Y, Koszinowski UH, Del Val M. HIV envelope protein inhibits MHC class I presentation of a cytomegalovirus protective epitope. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:4238-44. [PMID: 11591745 DOI: 10.4049/jimmunol.167.8.4238] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CTL recognize peptides that derive from viral protein Ags by proteolytic processing and are presented by MHC class I molecules. In this study we tested whether coexpression of viral Ags in the same cell leads to competition between them. To this end, two L(d)-restricted epitopes derived from HIV-1 envelope gp160 (ENV) and from CMV pp89 phosphoprotein were coexpressed. HIV ENV strain IIIB, but not MN variant, impaired recognition by specific CTL of CMV pp89 epitope 9pp89. Susceptibility to inhibition after ENV coexpression was inversely related to the amount of antigenic 9pp89 peptide processed from different antigenic constructs. In line with it, competition decreased the yield of naturally processed antigenic 9pp89 peptide bound to MHC class I molecules in coinfected cells. Also, point mutants of the presenting MHC class I molecule differed in their competition pattern. Collectively, the data imply that competition operates at the step of MHC-peptide complex assembly or stabilization. We conclude that, although not the rule, in certain combinations there is interference between different Ags expressed in the same cell and presented by the same MHC class I allele. These studies have implications for vaccine development and for understanding immunodominance.
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Affiliation(s)
- D López
- Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Madrid, Spain
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34
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Geginat G, Schenk S, Skoberne M, Goebel W, Hof H. A novel approach of direct ex vivo epitope mapping identifies dominant and subdominant CD4 and CD8 T cell epitopes from Listeria monocytogenes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:1877-84. [PMID: 11160235 DOI: 10.4049/jimmunol.166.3.1877] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We used a novel approach for the direct ex vivo identification and characterization of T cell epitopes based on the screening of peptide spot libraries with freshly isolated splenocytes in a sensitive enzyme-linked immunospot (ELISPOT) assay. This technique was applied for the analysis of splenocytes from Listeria monocytogenes-infected BALB/c and C57BL/6 mice. The screening of peptide spot libraries covering the whole listeriolysin O and p60 of L. monocytogenes confirmed all known CD4 and CD8 T cell epitopes of these proteins and additionally revealed six new H-2(d) and six new H-2(b)-restricted T cell epitopes. New epitopes were categorized into CD4 and CD8 T cell epitopes by ex vivo ELISPOT analysis with separated T cell populations. The quantitative analysis of cells reactive with these CD4 and CD8 T cell epitopes revealed the existence of dominant and subdominant CD4 and CD8 T cell populations during L. monocytogenes infection. As a consequence of these data we suggest that ELISPOT-based screening of peptide spot libraries could be a general approach for the rapid identification and characterization of pathogen-specific T cell populations during various infectious diseases.
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Affiliation(s)
- G Geginat
- Institut für Medizinische Mikrobiologie und Hygiene, Fakultät für Klinische Medizin Mannheim der Universität Heidelberg, Mannheim, Germany.
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35
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Schwarz K, Eggers M, Soza A, Koszinowski UH, Kloetzel PM, Groettrup M. The proteasome regulator PA28alpha/beta can enhance antigen presentation without affecting 20S proteasome subunit composition. Eur J Immunol 2000; 30:3672-9. [PMID: 11169410 DOI: 10.1002/1521-4141(200012)30:12<3672::aid-immu3672>3.0.co;2-b] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PA28alpha/beta is a regulatory complex of the 20S proteasome which consists of two IFN-gamma inducible subunits. Both subunits, alpha and beta, contribute equally to the formation of hexa- or heptameric rings which can associate with the 20S proteasome. Previously, we have shown that overexpression of the PA28alpha subunit enhanced the MHC class I-restricted presentation of two viral epitopes and that purified PA28alpha/beta accelerated T cell epitope generation by the 20S proteasome in vitro, indicating a role for PA28alpha/beta in antigen presentation. This conclusion was recently confirmed in PA28beta gene targeted mice which were severely deficient in MHC class I-restricted antigen presentation. These mice displayed a defect in the assembly of immunoproteasomes, suggesting that a lack of the proteasome subunits LMP2, LMP7, and MECL-1 may account for the deficiency in antigen presentation. In this study we investigated whether the effect of PA28alpha/beta on antigen presentation is dependent on a change of proteasome subunit composition. We have analyzed the assembly and subunit composition of proteasomes in fibroblast transfectants overexpressing both, alpha and beta subunits of PA28. In these transfectants we found a marked enhancement in the presentation of the immunodominant H-2Ld-restricted pp89 epitope of murine cytomegalovirus, although the 20S proteasome composition was the same as in recipient cells. We, therefore, conclude that PA28alpha/beta can enhance antigen processing independently of changes in 20S proteasome subunit composition or assembly.
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Affiliation(s)
- K Schwarz
- Research Department, Cantonal Hospital St. Gall, St. Gallen, Switzerland
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36
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López D, Gil-Torregrosa BC, Bergmann C, Del Val M. Sequential cleavage by metallopeptidases and proteasomes is involved in processing HIV-1 ENV epitope for endogenous MHC class I antigen presentation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:5070-7. [PMID: 10799863 DOI: 10.4049/jimmunol.164.10.5070] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Antigenic peptides derived from viral proteins by multiple proteolytic cleavages are bound by MHC class I molecules and recognized by CTL. Processing predominantly takes place in the cytosol of infected cells by the action of proteasomes. To identify other proteases involved in the endogenous generation of viral epitopes, specifically those derived from proteins routed to the secretory pathway, we investigated presentation of the HIV-1 ENV 10-mer epitope 318RGPGRAFVTI327 (p18) to specific CTL in the presence of diverse protease inhibitors. Both metalloproteinase and proteasome inhibitors decreased CTL recognition of the p18 epitope expressed from either native gp160 or from a chimera based on the hepatitis B virus secretory core protein as carrier protein. Processing of this epitope from both native ENV and the hepatitis B virus secretory core chimeric protein appeared to proceed by a TAP-dependent pathway that involved sequential cleavage by proteasomes and metallo-endopeptidases; however, other protease activities could replace the function of the lactacystin-sensitive proteasomes. By contrast, in a second TAP-independent pathway we detected no contribution of metallopeptidases for processing the ENV epitope from the chimeric protein. These results show that, in the classical TAP-dependent MHC class I pathway, endogenous Ag processing of viral proteins to yield the p18 10-mer epitope requires metallo-endopeptidases in addition to proteasomes.
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Affiliation(s)
- D López
- Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Madrid, Spain
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37
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Holtappels R, Thomas D, Podlech J, Geginat G, Steffens HP, Reddehase MJ. The putative natural killer decoy early gene m04 (gp34) of murine cytomegalovirus encodes an antigenic peptide recognized by protective antiviral CD8 T cells. J Virol 2000; 74:1871-84. [PMID: 10644360 PMCID: PMC111665 DOI: 10.1128/jvi.74.4.1871-1884.2000] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several early genes of murine cytomegalovirus (MCMV) encode proteins that mediate immune evasion by interference with the major histocompatibility complex class I (MHC-I) pathway of antigen presentation to cytolytic T lymphocytes (CTL). Specifically, the m152 gene product gp37/40 causes retention of MHC-I molecules in the endoplasmic reticulum (ER)-Golgi intermediate compartment. Lack of MHC-I on the cell surface should activate natural killer (NK) cells recognizing the "missing self." The retention, however, is counteracted by the m04 early gene product gp34, which binds to folded MHC-I molecules in the ER and directs the complex to the cell surface. It was thus speculated that gp34 might serve to silence NK cells and thereby complete the immune evasion of MCMV. In light of these current views, we provide here results demonstrating an in vivo role for gp34 in protective antiviral immunity. We have identified an antigenic nonapeptide derived from gp34 and presented by the MHC-I molecule D(d). Besides the immunodominant immediate-early nonapeptide consisting of IE1 amino acids 168-176 (IE1(168-176)), the early nonapeptide m04(243-251) is the second antigenic peptide described for MCMV. The primary immune response to MCMV generates significant m04-specific CD8 T-cell memory. Upon adoptive transfer into immunodeficient recipients, an m04-specific CTL line controls MCMV infection with an efficacy comparable to that of an IE1-specific CTL line. Thus, gp34 is the first noted early protein of MCMV that escapes viral immune evasion mechanisms. These data document that MCMV is held in check by a redundance of protective CD8 T cells recognizing antigenic peptides in different phases of viral gene expression.
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Affiliation(s)
- R Holtappels
- Institute for Virology, Johannes Gutenberg University, 55101 Mainz, Germany
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38
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Krmpotic A, Messerle M, Crnkovic-Mertens I, Polic B, Jonjic S, Koszinowski UH. The immunoevasive function encoded by the mouse cytomegalovirus gene m152 protects the virus against T cell control in vivo. J Exp Med 1999; 190:1285-96. [PMID: 10544200 PMCID: PMC2195686 DOI: 10.1084/jem.190.9.1285] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Cytomegaloviruses encode numerous functions that inhibit antigen presentation in the major histocompatibility complex (MHC) class I pathway in vitro. One example is the mouse cytomegalovirus (MCMV) glycoprotein gp40, encoded by the m152 gene, which selectively retains murine but not human MHC class I complexes in the endoplasmic reticulum-Golgi intermediate compartment/cis-Golgi compartment (Ziegler, H., R. Thäle, P. Lucin, W. Muranyi, T. Flohr, H. Hengel, H. Farrell, W. Rawlinson, and U.H. Koszinowski. 1997. Immunity. 6:57-66). To investigate the in vivo significance of this gene function during MCMV infection of the natural host, we constructed recombinants of MCMV in which the m152 gene was deleted, as were the corresponding virus revertants. We report on the following findings: Deletion of the m152 gene has no effect on virus replication in cell culture, whereas after infection of mice, the m152-deficient virus replicates to significantly lower virus titers. This attenuating effect is lifted by reinsertion of the gene into the mutant. Mutants and revertants grow to the same titer in animals deprived of the function targeted by the viral gene function, namely in mice deficient in beta2-microglobulin, mice deficient in the CD8 molecule, and mice depleted of T cells. Upon adoptive transfer of naive lymphocytes into infected mice, the absence of the m152 gene function sensitizes the virus to primary lymphocyte control. These results prove that MHC-reactive functions protect CMVs against attack by CD8(+) T lymphocytes in vivo.
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Affiliation(s)
- Astrid Krmpotic
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia
| | - Martin Messerle
- Max von Pettenkofer-Institute for Hygiene and Medical Microbiology, Ludwig-Maximilians-University of Munich, D-80336 Munich, Germany
| | - Irena Crnkovic-Mertens
- Max von Pettenkofer-Institute for Hygiene and Medical Microbiology, Ludwig-Maximilians-University of Munich, D-80336 Munich, Germany
| | - Bojan Polic
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia
| | - Stipan Jonjic
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia
| | - Ulrich H. Koszinowski
- Max von Pettenkofer-Institute for Hygiene and Medical Microbiology, Ludwig-Maximilians-University of Munich, D-80336 Munich, Germany
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39
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Montoya M, Del Val M. Intracellular Rate-Limiting Steps in MHC Class I Antigen Processing. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.4.1914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Abstract
Quantitative aspects of the endogenous pathway of Ag processing and presentation by MHC class I molecules to CD8+ CTL were analyzed over a wide range of Ag expression in recombinant vaccinia virus-infected cells expressing β-galactosidase as model Ag. Only the amount of starting Ag was varied, leaving other factors unaltered. Below a certain level of Ag synthesis, increasing protein amounts led to a sharp rise in recognition by CTL. Higher levels of Ag expression led to a saturation point, which intracellularly limited the number of naturally processed peptides bound to MHC and thereby also CTL recognition. The rate-limiting step was located at the binding of the antigenic peptide to MHC inside the vaccinia virus-infected cell or before this event.
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Affiliation(s)
- María Montoya
- Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Madrid, Spain
| | - Margarita Del Val
- Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Madrid, Spain
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40
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Abstract
Human cytomegalovirus is ubiquitous, yet causes little illness in immunocompetent individuals. Disease is evident in immunodeficient groups such as neonates, transplant recipients and AIDS patients either following a primary infection or reactivation of a latent infection. Little is known of the mechanisms underlying the pathogenicity of the virus. The recent determination of the nucleotide sequence of both human cytomegalovirus (strain AD169) and murine cytomegalovirus (murine cytomegalovirus strain Smith) has allowed an analysis of the biological importance of several virus genes. Studies with human cytomegalovirus have indicated that many viral genes are non-essential for replication in vitro which are thus assumed to be important in the pathogenesis of the virus. This is being examined in the murine model where the role of the gene and its product in disease can be directly examined in vivo using viral mutants in which the relevant gene has been interrupted or deleted. Current information on the role of cytomegalovirus genes in tissue tropism, immune evasion, latency, reactivation from latency and damage is described.
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Affiliation(s)
- C Sweet
- School of Biological Sciences, University of Birmingham, UK.
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41
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Kurz SK, Rapp M, Steffens HP, Grzimek NK, Schmalz S, Reddehase MJ. Focal transcriptional activity of murine cytomegalovirus during latency in the lungs. J Virol 1999; 73:482-94. [PMID: 9847354 PMCID: PMC103855 DOI: 10.1128/jvi.73.1.482-494.1999] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interstitial pneumonia is a frequent and critical manifestation of human cytomegalovirus (CMV) disease in immunocompromised patients, in particular in recipients of bone marrow transplantation. Previous work in the murine CMV infection model has identified the lungs as a major organ site of CMV latency and recurrence. It was open to question whether the viral genome is transcriptionally silent or active during latency. Transcription could be latency associated and thus be part of the latency phenotype. Alternatively, transcriptional activity could reflect episodes of reactivation. We demonstrate here that transcription of the immediate-early (IE) transcription unit ie1-ie3 selectively generates ie1-specific transcripts during latency. Notably, while the latent viral DNA was found to be evenly distributed in the lungs, transcription was focal and randomly distributed. This finding indicates that IE transcription is not a feature inherent to murine CMV latency but rather reflects foci of primordial reactivation. However, this reactivation did not initiate productive infection, since ie3 gene mRNA specifying the essential transactivator IE3 of murine CMV early gene expression was not detectable. Accordingly, transcripts encoding gB were absent during latency. By contrast, during induced virus recurrence, IE-phase transcription switched from focal to generalized and ie3-specific transcripts were generated. These data imply that latency and recurrence are regulated not only at the IE promoter-enhancer and that there exists an additional checkpoint at the level of precursor RNA splicing. We propose that focal transcription reflects random episodes of nonproductive reactivation that get terminated before IE3 is expressed and ignites the productive cycle.
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Affiliation(s)
- S K Kurz
- Institute for Virology, Johannes Gutenberg-University, Mainz, Germany
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42
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Gil-Torregrosa BC, Raúl Castaño A, Del Val M. Major histocompatibility complex class I viral antigen processing in the secretory pathway defined by the trans-Golgi network protease furin. J Exp Med 1998; 188:1105-16. [PMID: 9743529 PMCID: PMC2212533 DOI: 10.1084/jem.188.6.1105] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Classical antigen presentation by major histocompatibility complex class I molecules involves cytosolic processing of endogenously synthesized antigens by proteasomes and translocation of processed peptides into the endoplasmic reticulum (ER) by transporters associated with antigen presentation (TAP). Alternative pathways for processing of endogenous antigens, generally involving the ER, have been suggested but not fully proved. We analyzed the potential for class I presentation of proteolytic maturation of secretory antigens in the exocytic pathway. We found that hepatitis B (HB) virus secretory core protein HBe can efficiently deliver COOH-terminally located antigenic peptides for endogenous class I loading in the absence of TAP. Antigen presentation to specific cytotoxic T lymphocytes correlates with protein maturation at the COOH terminus, since modification of maturation and transport of HBe through the secretory pathway alters antigen presentation. Both maturation and a necessary processing step occur in the Golgi or post-Golgi compartment. Antigen presentation is independent of proteasome activity, but inhibitors of the trans-Golgi network resident protease furin inhibit both HBe maturation and antigen presentation. These results define a new antigen processing pathway located in the secretory route, with a central role for proteolytic maturation mediated by the subtilisin protease family member furin as an efficient source for antigen presentation.
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Affiliation(s)
- B C Gil-Torregrosa
- Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Madrid, Spain
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43
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Holtappels R, Podlech J, Geginat G, Steffens HP, Thomas D, Reddehase MJ. Control of murine cytomegalovirus in the lungs: relative but not absolute immunodominance of the immediate-early 1 nonapeptide during the antiviral cytolytic T-lymphocyte response in pulmonary infiltrates. J Virol 1998; 72:7201-12. [PMID: 9696814 PMCID: PMC109942 DOI: 10.1128/jvi.72.9.7201-7212.1998] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/1998] [Accepted: 06/12/1998] [Indexed: 11/20/2022] Open
Abstract
The lungs are a major organ site of cytomegalovirus (CMV) infection, pathogenesis, and latency. Interstitial CMV pneumonia represents a critical manifestation of CMV disease, in particular in recipients of bone marrow transplantation (BMT). We have employed a murine model for studying the immune response to CMV in the lungs in the specific scenario of immune reconstitution after syngeneic BMT. Control of pulmonary infection was associated with a vigorous infiltration of the lungs, which was characterized by a preferential recruitment and massive expansion of the CD8 subset of alpha/beta T cells. The infiltrate provided a microenvironment in which the CD8 T cells differentiated into mature effector cells, that is, into functionally active cytolytic T lymphocytes (CTL). This gave us the opportunity for an ex vivo testing of the antigen specificities of CTL present at a relevant organ site of viral pathogenesis. The contribution of the previously identified immediate-early 1 (IE1) nonapeptide of murine CMV was evaluated by comparison with the CD3epsilon-redirected cytolytic activity used as a measure of the overall CTL response in the lungs. The IE1 peptide was detected by pulmonary CTL, but it accounted for a minor part of the response. Interestingly, no additional viral or virus-induced antigenic peptides were detectable among naturally processed peptides derived from infected lungs, even though infected fibroblasts were recognized in a major histocompatibility complex-restricted manner. We conclude that the antiviral pulmonary immune response is a collaborative function that involves many antigenic peptides, among which the IE1 peptide is immunodominant in a relative sense.
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Affiliation(s)
- R Holtappels
- Institute for Virology, Johannes Gutenberg-University, 55101 Mainz, Germany
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44
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Schmidtke G, Eggers M, Ruppert T, Groettrup M, Koszinowski UH, Kloetzel PM. Inactivation of a defined active site in the mouse 20S proteasome complex enhances major histocompatibility complex class I antigen presentation of a murine cytomegalovirus protein. J Exp Med 1998; 187:1641-6. [PMID: 9584142 PMCID: PMC2212286 DOI: 10.1084/jem.187.10.1641] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Proteasomes generate peptides bound by major histocompatibility complex (MHC) class I molecules. Avoiding proteasome inhibitors, which in most cases do not distinguish between individual active sites within the cell, we used a molecular genetic approach that allowed for the first time the in vivo analysis of defined proteasomal active sites with regard to their significance for antigen processing. Functional elimination of the delta/low molecular weight protein (LMP) 2 sites by substitution with a mutated inactive LMP2 T1A subunit results in reduced cell surface expression of the MHC class I H-2Ld and H-2Dd molecules. Surface levels of H-2Ld and H-2Dd molecules were restored by external loading with peptides. However, as a result of the active site mutation, MHC class I presentation of a 9-mer peptide derived from a protein of murine cytomegalovirus was enhanced about three- to fivefold. Our experiments provide evidence that the delta/LMP2 active site elimination limits the processing and presentation of several peptides, but may be, nonetheless, beneficial for the generation and presentation of others.
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Affiliation(s)
- G Schmidtke
- Zentrum für Experimentelle Medizin (ZEM), Institut für Biochemie, Charité, Humboldt Universität zu Berlin, 10117 Berlin, Germany
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45
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Jelonek MT, Classon BJ, Hudson PJ, Margulies DH. Direct Binding of the MHC Class I Molecule H-2Ld to CD8: Interaction with the Amino Terminus of a Mature Cell Surface Protein. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.6.2809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
MHC class I molecules (MHC-I) display peptides from the intracellular pool at the cell surface for recognition by T lymphocytes bearing αβ TCR. Although the activation of T cells is controlled by the interaction of the TCR with MHC/peptide complexes, the degree and extent of the activation is influenced by the binding in parallel of the CD8 coreceptor with MHC-I. In the course of quantitative evaluation of the binding of purified MHC-I to engineered CD8, we observed that peptide-deficient H-2Ld (MHC-I) molecules bound with moderate affinity (Kd = 7.96 × 10−7 M), but in the presence of H-2Ld-binding peptides, no interaction was observed. Examination of the amino terminal sequences of CD8α and β chains suggested that H-2Ld might bind these protein termini via its peptide binding cleft. Using both competition and real-time direct assays based on surface plasmon resonance, we detected binding of empty H-2Ld to synthetic peptides representing these termini. These results suggest that some MHC molecules are capable of binding the amino termini of intact cell surface proteins through their binding groove and provide alternative explanations for the observed binding of MHC molecules to a variety of cell surface receptors and coreceptors.
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Affiliation(s)
- Marie T. Jelonek
- *Molecular Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Brendan J. Classon
- †The Walter and Eliza Hall Institute of Medical Research, Victoria, Australia; and
| | - Peter J. Hudson
- ‡CSIRO Molecular Science, CRC for Diagnostic Technologies, Victoria, Australia
| | - David H. Margulies
- *Molecular Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
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46
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MacDonald MR, Li XY, Stenberg RM, Campbell AE, Virgin HW. Mucosal and parenteral vaccination against acute and latent murine cytomegalovirus (MCMV) infection by using an attenuated MCMV mutant. J Virol 1998; 72:442-51. [PMID: 9420244 PMCID: PMC109393 DOI: 10.1128/jvi.72.1.442-451.1998] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/1997] [Accepted: 08/19/1997] [Indexed: 02/05/2023] Open
Abstract
We used a live attenuated murine cytomegalovirus (MCMV) mutant to analyze mechanisms of vaccination against acute and latent CMV infection. We selected MCMV mutant RV7 as a vaccine candidate since this virus grows well in tissue culture but is profoundly attenuated for growth in normal and severe combined immunodeficient (SCID) mice (V. J. Cavanaugh et al., J. Virol. 70:1365-1374, 1996). BALB/c mice were immunized twice (0 and 14 days) subcutaneously (s.c.) with tissue culture-passaged RV7 and then challenged with salivary gland-passaged wild-type MCMV (sgMCMV) intraperitoneally (i.p.) on day 28. RV7 vaccination protected mice against challenge with 10(5) PFU of sgMCMV, a dose that killed 100% of mock-vaccinated mice. RV7 vaccination reduced MCMV replication 100- to 500-fold in the spleen between 1 and 8 days after challenge. We used the capacity to control replication of MCMV in the spleen 4 days after challenge as a surrogate for protection. Protection was antigen specific and required both live RV7 and antigen-specific lymphocytes. Interestingly, RV7 was effective when administered s.c., i.p., perorally, intranasally, and intragastrically, demonstrating that attenuated CMV applied to mucosal surfaces can elicit protection against parenteral virus challenge. B cells and immunoglobulin G were not essential for RV7-induced immunity since B-cell-deficient mice were effectively vaccinated by RV7. CD8 T cells, but not CD4 T cells, were critical for RV7-induced protection. Depletion of CD8 T cells by passive transfer of monoclonal anti-CD8 (but not anti-CD4) antibody abrogated RV7-mediated protection, and RV7 vaccination was less efficient in CD8 T-cell-deficient mice with a targeted mutation in the beta2-microglobulin gene. Although gamma interferon is important for innate resistance to MCMV, it was not essential for RV7 vaccination since gamma interferon receptor-deficient mice were protected by RV7 vaccination. Establishment of and/or reactivation from latency by sgMCMV was decreased by RV7 vaccination, as measured by diminished reactivation of MCMV from splenic explants. We found no evidence for establishment of splenic latency by RV7 after s.c. vaccination. We conclude that RV7 administered through both systemic and mucosal routes is an effective vaccine against MCMV infection. It may be possible to design human CMV vaccines with similar properties.
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Affiliation(s)
- M R MacDonald
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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47
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Messerle M, Crnkovic I, Hammerschmidt W, Ziegler H, Koszinowski UH. Cloning and mutagenesis of a herpesvirus genome as an infectious bacterial artificial chromosome. Proc Natl Acad Sci U S A 1997; 94:14759-63. [PMID: 9405686 PMCID: PMC25110 DOI: 10.1073/pnas.94.26.14759] [Citation(s) in RCA: 340] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A strategy for cloning and mutagenesis of an infectious herpesvirus genome is described. The mouse cytomegalovirus genome was cloned and maintained as a 230 kb bacterial artificial chromosome (BAC) in E. coli. Transfection of the BAC plasmid into eukaryotic cells led to a productive virus infection. The feasibility to introduce targeted mutations into the BAC cloned virus genome was shown by mutation of the immediate-early 1 gene and generation of a mutant virus. Thus, the complete construction of a mutant herpesvirus genome can now be carried out in a controlled manner prior to the reconstitution of infectious progeny. The described approach should be generally applicable to the mutagenesis of genomes of other large DNA viruses.
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Affiliation(s)
- M Messerle
- Max von Pettenkofer-Institut für Hygiene und Mikrobiologie, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, D-81377 Munich, Germany.
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48
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Kleijnen MF, Huppa JB, Lucin P, Mukherjee S, Farrell H, Campbell AE, Koszinowski UH, Hill AB, Ploegh HL. A mouse cytomegalovirus glycoprotein, gp34, forms a complex with folded class I MHC molecules in the ER which is not retained but is transported to the cell surface. EMBO J 1997; 16:685-94. [PMID: 9049298 PMCID: PMC1169670 DOI: 10.1093/emboj/16.4.685] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Murine cytomegalovirus (MCMV) interferes with antigen presentation by means of retaining major histocompatibility complex (MHC) class I molecules in the endoplasmic reticulum (ER). Here we identify and characterize an MCMV-encoded glycoprotein, gp34, which tightly associates with properly conformed MHC class I molecules in the ER. Gp34 is synthesized in large quantities during MCMV infection and it leaves the ER only in association with MHC class I complexes. Many but not all class I molecules are retained in the ER during the early phase of MCMV infection, and we observe an inverse correlation between amounts of gp34 synthesized during the course of infection and class I retention. An MCMV deletion mutant lacking several genes, including the gene encoding gp34, shows increased class I retention. Thus, MCMV gp34 may counteract class I retention, perhaps to decrease susceptibility of infected cells to recognition by natural killer cells.
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Affiliation(s)
- M F Kleijnen
- Center for Cancer Research, Massachusetts Institute of Technology, Cambridge 02139, USA
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49
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Ziegler H, Thale R, Lucin P, Muranyi W, Flohr T, Hengel H, Farrell H, Rawlinson W, Koszinowski UH. A mouse cytomegalovirus glycoprotein retains MHC class I complexes in the ERGIC/cis-Golgi compartments. Immunity 1997; 6:57-66. [PMID: 9052837 DOI: 10.1016/s1074-7613(00)80242-3] [Citation(s) in RCA: 206] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The principle by which mouse cytomegalovirus blocks antigen presentation in the MHC class I pathway was investigated. The responsible gene m152, encoding a type I transmembrane glycoprotein of 40 kDa, is a member of a gene family located in the right-hand terminal region of the 230 kb virus genome. Expression of m152 in murine and human cells arrested the export of mouse class I complexes from the ER-Golgi intermediate compartment/cis-Golgi compartment and inhibited lysis by cytotoxic T cells. The plasma membrane transport of human MHC class I molecules was not affected. The deletion of the cytoplasmic tail of gp40 did not lift its effect on class I molecule export, indicating that this protein differs in its functions from known immunosubversive viral gene products and represents a novel principle by which a herpesvirus shuts off MHC class I function.
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Affiliation(s)
- H Ziegler
- Max von Pettenkofer Institut, Ludwig-Maximilians-Universitat, Munchen, Federal Republic of Germany
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50
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Hill AB. Mechanisms of interference with the MHC class I-restricted pathway of antigen presentation by herpesviruses. Immunol Cell Biol 1996; 74:523-6. [PMID: 8989590 DOI: 10.1038/icb.1996.85] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Herpesviruses are an ancient, ubiquitous family of DNA viruses, most of which share a lifestyle of latently or persistently infecting a young host, and spreading to infect a new host a generation later. Most herpesviruses interfere with antigen presentation via the MHC class I-restricted pathway of antigen presentation, suggesting that impairment of the cytotoxic T lymphocyte response is necessary for the maintenance of this lifestyle. The diverse molecular mechanisms that have so far been discovered employed by Epstein-Barr virus, herpes simplex viruses, and human and murine cytomegaloviruses are described in this review.
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Affiliation(s)
- A B Hill
- Department of Molecular Microbiology and Immunology, Oregon Health Sciences University, Portland 97201, USA
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