scholarly journals Mouse Norovirus Infection Reduces the Surface Expression of Major Histocompatibility Complex Class I Proteins and Inhibits CD8+T Cell Recognition and Activation

2018 ◽  
Vol 92 (18) ◽  
Author(s):  
Svenja Fritzlar ◽  
Sinthujan Jegaskanda ◽  
Turgut Esad Aktepe ◽  
Julia Emiley Prier ◽  
Lauren Elise Holz ◽  
...  
Keyword(s):  
Immune Response ◽  
Antigen Presentation ◽  
Mhc Class I ◽  
Viral Antigen ◽  
Surface Expression ◽  
Host Immune Response ◽  
Class I ◽  
Immune Memory ◽  
Histocompatibility Complex ◽  
Infected Cells

ABSTRACTHuman noroviruses are highly infectious single-stranded RNA (ssRNA) viruses and the major cause of nonbacterial gastroenteritis worldwide. With the discovery of murine norovirus (MNV) and the introduction of an effective model for norovirus infection and replication, knowledge about infection mechanisms and their impact on the host immune response has progressed. A major player in the immune response against viral infections is the group of major histocompatibility complex (MHC) class I proteins, which present viral antigen to immune cells. We have observed that MNV interferes with the antigen presentation pathway in infected cells by reducing the surface expression of MHC class I proteins. We have shown that MNV-infected dendritic cells or macrophages have lower levels of surface expression of MHC class I proteins than uninfected and bystander cells. Transcriptional analysis revealed that this defect is not due to a decreased amount of mRNA but is reflected at the protein level. We have determined that this defect is mediated via the MNV NS3 protein. Significantly, treatment of MNV-infected cells with the endocytic recycling inhibitor dynasore completely restored the surface expression of MHC class I proteins, whereas treatment with the proteasome inhibitor MG132 partly restored such expression. These observations indicate a role for endocytic recycling and proteasome-mediated degradation of these proteins. Importantly, we show that due to the reduced surface expression of MHC class I proteins, antigen presentation is inhibited, resulting in the inability of CD8+T cells to become activated in the presence of MNV-infected cells.IMPORTANCEHuman noroviruses (HuNoVs) are the major cause of nonbacterial gastroenteritis worldwide and impose a great burden on patients and health systems every year. So far, no antiviral treatment or vaccine is available. We show that MNV evades the host immune response by reducing the amount of MHC class I proteins displayed on the cell surface. This reduction leads to a decrease in viral antigen presentation and interferes with the CD8+T cell response. CD8+T cells respond to foreign antigen by activating cytotoxic pathways and inducing immune memory to the infection. By evading this immune response, MNV is able to replicate efficiently in the host, and the ability of cells to respond to consecutive infections is impaired. These findings have a major impact on our understanding of the ways in which noroviruses interact with the host immune response and manipulate immune memory.

scholarly journals Processing and MHC class I presentation of human cytomegalovirus pp65-derived peptides persist despite gpUS2–11-mediated immune evasion

2007 ◽  
Vol 88 (5) ◽  
pp. 1429-1439 ◽  
Author(s):  
Katrin Besold ◽  
Nadine Frankenberg ◽  
Sandra Pepperl-Klindworth ◽  
Jürgen Kuball ◽  
Matthias Theobald ◽  
...  
Keyword(s):  
Antigen Presentation ◽  
Mhc Class I ◽  
Human Cytomegalovirus ◽  
Class I ◽  
Productive Infection ◽  
Antigenic Peptides ◽  
Histocompatibility Complex ◽  
The Face ◽  
Infected Cells ◽  
Partial Suppression

Immune control of human cytomegalovirus (HCMV) infection can be mediated by CD8+ cytolytic T lymphocytes (CTL). Adoptive transfer of antiviral CTL confers protection against HCMV reactivation and disease. The tegument protein pp65 and the immediate-early 1 protein (IE1) are recognized to be major CTL targets, even though during productive infection the viral immunoevasion proteins gpUS2–11 act to suppress major histocompatibility complex (MHC) class I-restricted antigen presentation. Thus it was not clear how infected cells could be labelled with antigenic peptides in the face of immunoevasion. We show here that the immunodominant peptide pp65NLV was presented by MHC class I in cells infected with a gpUS2–11-competent virus. Presentation of pp65NLV was still detectable at 96 h post-infection, although at low levels. Partial suppression of pp65NLV presentation was dependent on the ability of the infecting strain to express gpUS2–11. MHC class I-restricted antigen presentation in HCMV-infected cells (encoding gpUS2–11) exhibited specificity for pp65-derived peptides, as infected fibroblasts did not present the IE1-derived nonapeptide IE1TMY. Remarkably, infected cells could restore pp65NLV peptide presentation after acid removal of MHC class I despite gpUS2–11 expression. This recovery was shown to be dependent on proteasome functionality. In contrast to IE1, pp65 peptides are loaded on MHC class I molecules to be transported to the cell surface at early and late times after infection in the face of gpUS2–11-mediated immunoevasion. pp65 is therefore the first example of an HCMV protein only incompletely subjected to gpUS2–11-mediated immunoevasion.

scholarly journals The Lytic Cycle of Epstein-Barr Virus Is Associated with Decreased Expression of Cell Surface Major Histocompatibility Complex Class I and Class II Molecules

2002 ◽  
Vol 76 (16) ◽  
pp. 8179-8188 ◽  
Author(s):  
Sinéad Keating ◽  
Stuart Prince ◽  
Matthew Jones ◽  
Martin Rowe
Keyword(s):  
Cell Surface ◽  
Mhc Class I ◽  
Surface Expression ◽  
Lytic Cycle ◽  
Class I ◽  
Cell Surface Expression ◽  
Barr Virus ◽  
Histocompatibility Complex ◽  
Infected Cells ◽  
Epstein Barr

ABSTRACT Human herpesviruses utilize an impressive range of strategies to evade the immune system during their lytic replicative cycle, including reducing the expression of cell surface major histocompatibility complex (MHC) and immunostimulatory molecules required for recognition and lysis by virus-specific cytotoxic T cells. Study of possible immune evasion strategies by Epstein-Barr virus (EBV) in lytically infected cells has been hampered by the lack of an appropriate permissive culture model. Using two-color immunofluorescence staining of cell surface antigens and EBV-encoded lytic cycle antigens, we examined EBV-transformed B-cell lines in which a small subpopulation of cells had spontaneously entered the lytic cycle. Cells in the lytic cycle showed a four- to fivefold decrease in cell surface expression of MHC class I molecules relative to that in latently infected cells. Expression of MHC class II molecules, CD40, and CD54 was reduced by 40 to 50% on cells in the lytic cycle, while no decrease was observed in cell surface expression of CD19, CD80, and CD86. Downregulation of MHC class I expression was found to be an early-lytic-cycle event, since it was observed when progress through late lytic cycle was blocked by treatment with acyclovir. The immediate-early transactivator of the EBV lytic cycle, BZLF1, did not directly affect expression of MHC class I molecules. However, BZLF1 completely inhibited the upregulation of MHC class I expression mediated by the EBV cell-transforming protein, LMP1. This novel function of BZLF1 elucidates the paradox of how MHC class I expression can be downregulated when LMP1, which upregulates MHC class I expression in latent infection, remains expressed in the lytic cycle.

scholarly journals The Multiple Immune-Evasion Genes of Murine Cytomegalovirus Are Not Redundant

2001 ◽  
Vol 194 (7) ◽  
pp. 967-978 ◽  
Author(s):  
Daniel G. Kavanagh ◽  
Marielle C. Gold ◽  
Markus Wagner ◽  
Ulrich H. Koszinowski ◽  
Ann B. Hill
Keyword(s):  
Antigen Presentation ◽  
Mhc Class I ◽  
Cytotoxic T Lymphocytes ◽  
Immune Evasion ◽  
Surface Expression ◽  
Class I ◽  
Murine Cytomegalovirus ◽  
Histocompatibility Complex ◽  
Golgi Compartment ◽  
Partial Retention

Both human cytomegaloviruses (HCMVs) and murine cytomegaloviruses (MCMVs) encode multiple genes that interfere with antigen presentation by major histocompatibility complex (MHC) class I, and thus protect infected targets from lysis by virus-specific cytotoxic T lymphocytes (CTLs). HCMV has been shown to encode four such genes and MCMV to encode two. MCMV m152 blocks the export of class I from a pre-Golgi compartment, and MCMV m6 directs class I to the lysosome for degradation. A third MCMV gene, m4, encodes a glycoprotein which is expressed at the cell surface in association with class I. Here we here show that m4 is a CTL-evasion gene which, unlike previously described immune-evasion genes, inhibited CTLs without blocking class I surface expression. m152 was necessary to block antigen presentation to both Kb- and Db-restricted CTL clones, while m4 was necessary to block presentation only to Kb-restricted clones. m152 caused complete retention of Db, but only partial retention of Kb, in a pre-Golgi compartment. Thus, while m152 effectively inhibited Db-restricted CTLs, m4 was required to completely inhibit Kb-restricted CTLs. We propose that cytomegaloviruses encode multiple immune-evasion genes in order to cope with the diversity of class I molecules in outbred host populations.

scholarly journals Major Histocompatibility Complex Class I Allele-specific Cooperative and Competitive Interactions between Immune Evasion Proteins of Cytomegalovirus

2002 ◽  
Vol 196 (6) ◽  
pp. 805-816 ◽  
Author(s):  
Markus Wagner ◽  
Anja Gutermann ◽  
Jürgen Podlech ◽  
Matthias J. Reddehase ◽  
Ulrich H. Koszinowski
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class I ◽  
Surface Expression ◽  
Inhibitory Effect ◽  
Class I ◽  
Major Influence ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Allele Specific ◽  
Infected Cells

Cytomegaloviruses (CMVs) deploy a set of genes for interference with antigen presentation in the major histocompatibility complex (MHC) class I pathway. In murine CMV (MCMV), three genes were identified so far: m04/gp34, m06/gp48, and m152/gp40. While their function as immunoevasins was originally defined after their selective expression, this may not necessarily reflect their biological role during infection. The three immunoevasins might act synergistically, but they might also compete for their common substrate, the MHC class I complexes. To approach this question in a systematic manner, we have generated a complete set of mutant viruses with deletions of the three genes in all seven possible combinations. Surface expression of a set of MHC class I molecules specified by haplotypes H-2d (Kd, Dd, and Ld) and H-2b (Kb and Db) was the parameter for evaluation of the interference with class I trafficking. The data show the following: first, there exists no additional MCMV gene of major influence on MHC class I surface expression; second, the strength of the inhibitory effect of immunoevasins shows an allele-specific hierarchy; and third, the immunoevasins act not only synergistically but can, in certain combinations, interact antagonistically. In essence, this work highlights the importance of studying the immunosubversive mechanisms of cytomegaloviruses in the context of gene expression during the viral replicative cycle in infected cells.

scholarly journals Cellular and Molecular Requirements for Association of the Murine Cytomegalovirus Protein m4/gp34 with Major Histocompatibility Complex Class I Molecules

2006 ◽  
Vol 80 (12) ◽  
pp. 6048-6055 ◽  
Author(s):  
Xiuju Lu ◽  
Daniel G. Kavanagh ◽  
Ann B. Hill
Keyword(s):  
Major Histocompatibility Complex ◽  
Cell Surface ◽  
Antigen Presentation ◽  
Mhc Class I ◽  
Adenovirus Vector ◽  
Class I ◽  
Murine Cytomegalovirus ◽  
Histocompatibility Complex ◽  
Peptide Loading ◽  
Infected Cells

ABSTRACT The murine cytomegalovirus (MCMV) protein m4/gp34 is unique among known viral genes that target the major histocompatibility complex (MHC) class I pathway of antigen presentation in the following two ways: it is found in association with class I MHC molecules at the cell surface, and it inhibits antigen presentation without reducing cell surface class I levels. The current study was undertaken to define more clearly the structural and cellular requirements for m4/gp34 association with the MHC class I molecule Kb. We first assessed the role of the peptide-loading complex in m4/gp34-Kb association, using cell lines lacking TAP, tapasin, or β2m. m4/gp34-Kb complexes formed in the absence of TAP or tapasin, although not as efficiently as in wild-type cells. The expression of full-length and truncation mutants of m4/gp34 in a gutless adenovirus vector revealed that the transmembrane region of m4/gp34 was required for efficient association with the Kb heavy chain. However, the peptide-loading complex was not absolutely required for the association, since m4/gp34 readily formed complexes with Kb in detergent lysates. The addition of Kb-binding peptide to the detergent lysates facilitated but was not essential for the formation of the complexes. The ease of complex formation in detergent lysates contrasted with the small fractions of m4/gp34 and Kb that form complexes in infected cells, suggesting that the endoplasmic reticulum (ER) environment restricts access of m4/gp34 to Kb. Finally, although m4/gp34-Kb complexes could form when m4 was carried either by MCMV or by the adenovirus vector, they were only efficiently exported from the ER in MCMV-infected cells, suggesting that MCMV provides additional factors needed for transport of the complexes.

scholarly journals Macrophages Escape Inhibition of Major Histocompatibility Complex Class I-Dependent Antigen Presentation by Cytomegalovirus

2000 ◽  
Vol 74 (17) ◽  
pp. 7861-7868 ◽  
Author(s):  
Hartmut Hengel ◽  
Uwe Reusch ◽  
Gernot Geginat ◽  
Rafaela Holtappels ◽  
Thomas Ruppert ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Major Histocompatibility Complex ◽  
Antigen Presentation ◽  
Mhc Class I ◽  
Surface Expression ◽  
Class I ◽  
Major Histocompatibility ◽  
Mcmv Infection ◽  
Early Protein ◽  
Histocompatibility Complex

ABSTRACT The mouse cytomegalovirus (MCMV) m152- andm06-encoded glycoproteins gp40 and gp48, respectively, independently downregulate major histocompatibility complex (MHC) class I surface expression during the course of productive MCMV infection in fibroblasts. As a result, presentation of an immediate-early protein pp89-derived nonapeptide to H-2Ld -restricted CD8+ cytotoxic T cells is completely prevented in fibroblasts. Here we demonstrate that MCMV-infected primary bone marrow macrophages and the macrophage cell line J774 constitutively present pp89 peptides during permissive MCMV infection to cytotoxic T lymphocytes (CTL). In contrast to fibroblasts, expression of them152 and m06 genes in macrophages does not affect surface expression of MHC class I. Assessment of pp89 synthesis and quantification of extracted peptide revealed a significantly higher efficiency of macrophages than of fibroblasts to process pp89 into finally trimmed peptide. The yield of pp89 peptide determined in MCMV-infected tissues of bone marrow chimeras confirmed that bone marrow-derived cells represent a prime source of pp89 processing in parenchymal organs. The finding that macrophages resist the viral control of MHC I-dependent antigen presentation reconciles the paradox of efficient induction of CMV-specific CD8+ CTL in vivo despite extensive potential of CMVs to subvert MHC class I.

scholarly journals Retention of adenovirus E19 glycoprotein in the endoplasmic reticulum is essential to its ability to block antigen presentation.

1991 ◽  
Vol 174 (6) ◽  
pp. 1629-1637 ◽  
Author(s):  
J H Cox ◽  
J R Bennink ◽  
J W Yewdell
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Antigen Presentation ◽  
Viral Proteins ◽  
Genetically Engineered ◽  
Class I ◽  
Wild Type ◽  
Histocompatibility Complex ◽  
Infected Cells ◽  
Lumenal Domain

The E3/19K glycoprotein of adenovirus functions to diminish recognition of adenovirus-infected cells by major histocompatibility complex class I-restricted cytotoxic T lymphocytes (CTLs) by binding intracellular class I molecules and preventing them from reaching the plasma membrane. In the present study we have characterized the nature of the interaction between E3/19K and the H-2Kd (Kd) molecule. An E3/19K molecule genetically engineered to terminate six residues from its normal COOH terminus (delta E19), was found to associate with Kd in a manner indistinguishable from wild-type E3/19K. Unlike E3/19K, however, delta E19 was transported through the Golgi complex to the plasma membrane, where it could be detected biochemically and immunocytochemically using a monoclonal antibody specific for the lumenal domain of E3/19K. Importantly, delta E19 also differed from E3/19K in being unable to prevent the presentation of Kd-restricted viral proteins to CTLs. This is unlikely to be due to delta E19 having a lower avidity for Kd than E3/19K, since delta E19 was able to compete with E3/19K for Kd binding, both physically, and functionally in nullifying the E3/19K blockade of antigen presentation. These findings indicate that the ability of E3/19K to block antigen presentation is due solely to its ability to retain newly synthesized class I molecules in the endoplasmic reticulum.

scholarly journals Restoration of MHC Class I Surface Expression and Endogenous Antigen Presentation by a Molecular Chaperone

1997 ◽  
Vol 45 (6) ◽  
pp. 605-612 ◽  
Author(s):  
A. D. WELLS ◽  
S. K. RAI ◽  
M. S. SALVATO ◽  
H. BAND ◽  
M. MALKOVSKY
Keyword(s):  
Antigen Presentation ◽  
Mhc Class I ◽  
Molecular Chaperone ◽  
Surface Expression ◽  
Class I

scholarly journals Inhibition of Heavy Chain and β2-Microglobulin Synthesis as a Mechanism of Major Histocompatibility Complex Class I Downregulation during Epstein-Barr Virus Replication

2006 ◽  
Vol 81 (3) ◽  
pp. 1390-1400 ◽  
Author(s):  
Andre Ortlieb Guerreiro-Cacais ◽  
Mehmet Uzunel ◽  
Jelena Levitskaya ◽  
Victor Levitsky
Keyword(s):  
Mhc Class I ◽  
Mhc Class Ii ◽  
Heavy Chain ◽  
Epstein Barr Virus ◽  
Class I ◽  
Heavy Chains ◽  
Barr Virus ◽  
Histocompatibility Complex ◽  
Infected Cells ◽  
Epstein Barr

ABSTRACT The mechanisms of major histocompatibility complex (MHC) class I downregulation during Epstein-Barr virus (EBV) replication are not well characterized. Here we show that in several cell lines infected with a recombinant EBV strain encoding green fluorescent protein (GFP), the virus lytic cycle coincides with GFP expression, which thus can be used as a marker of virus replication. EBV replication resulted in downregulation of MHC class II and all classical MHC class I alleles independently of viral DNA synthesis or late gene expression. Although assembled MHC class I complexes, the total pool of heavy chains, and β2-microglobulin (β2m) were significantly downregulated, free class I heavy chains were stabilized at the surface of cells replicating EBV. Calnexin expression was increased in GFP+ cells, and calnexin and calreticulin accumulated at the cell surface that could contribute to the stabilization of class I heavy chains. Decreased expression levels of another chaperone, ERp57, and TAP2, a transporter associated with antigen processing and presentation, correlated with delayed kinetics of MHC class I maturation. Levels of both class I heavy chain and β2m mRNA were reduced, and metabolic labeling experiments demonstrated a very low rate of class I heavy chain synthesis in lytically infected cells. MHC class I and MHC class II downregulation was mimicked by pharmacological inhibition of protein synthesis in latently infected cells. Our data suggest that although several mechanisms may contribute to MHC class I downregulation in the course of EBV replication, inhibition of MHC class I synthesis plays the primary role in the process.

scholarly journals Cell Surface Expression of Major Histocompatibility Complex Class I Molecules Is Reduced in Hepatitis C Virus Subgenomic Replicon-Expressing Cells

2003 ◽  
Vol 77 (21) ◽  
pp. 11644-11650 ◽  
Author(s):  
Keith D. Tardif ◽  
Aleem Siddiqui
Keyword(s):  
Major Histocompatibility Complex ◽  
Hepatitis C ◽  
Cell Surface ◽  
Mhc Class I ◽  
Surface Expression ◽  
Protein Glycosylation ◽  
Class I ◽  
Cell Surface Expression ◽  
Histocompatibility Complex ◽  
Mhc Class I Molecules

ABSTRACT The hepatitis C virus (HCV) causes chronic hepatitis in most infected individuals by evading host immune defenses. In this investigation, we show that HCV-infected cells may go undetected in the immune system by suppressing major histocompatibility complex (MHC) class I antigen presentation to cytotoxic T lymphocytes. Cells expressing HCV subgenomic replicons have lower MHC class I cell surface expression. This is due to reduced levels of properly folded MHC class I molecules. HCV replicons induce endoplasmic reticulum (ER) stress (K. Tardif, K. Mori, and A. Siddiqui, J. Virol. 76:7453-7459, 2002), which results from a decline in protein glycosylation. Decreasing protein glycosylation can disrupt protein folding, preventing the assembly of MHC class I molecules. This results in the accumulation of unfolded MHC class I. Therefore, the persistence and pathogenesis of HCV may depend upon the ER stress-mediated interference of MHC class I assembly and cell surface expression.

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