Herpes Simplex Virus Type 1 (HSV-1)-Induced Apoptosis in Human Dendritic Cells as a Result of Downregulation of Cellular FLICE-Inhibitory Protein and Reduced Expression of HSV-1 Antiapoptotic Latency-Associated Transcript Sequences

ABSTRACT Herpes simplex virus type 1 (HSV-1) is one of the most frequent and successful human pathogens. It targets immature dendritic cells (iDCs) to interfere with the antiviral immune response. The mechanisms underlying apoptosis of HSV-1-infected iDCs are not fully understood. Previously, we have shown that HSV-1-induced apoptosis of iDCs is associated with downregulation of the cellular FLICE-inhibitory protein (c-FLIP), a potent inhibitor of caspase-8-mediated apoptosis. In this study, we prove that HSV-1 induces degradation of c-FLIP in a proteasome-independent manner. In addition, by using c-FLIP-specific small interfering RNA (siRNA) we show for the first time that downregulation of c-FLIP expression is sufficient to drive uninfected iDCs into apoptosis, underlining the importance of this molecule for iDC survival. Surprisingly, we also observed virus-induced c-FLIP downregulation in epithelial cells and many other cell types that do not undergo apoptosis after HSV-1 infection. Microarray analyses revealed that HSV-1-encoded latency-associated transcript (LAT) sequences, which can substitute for c-FLIP as an inhibitor of caspase-8-mediated apoptosis, are much less abundant in iDCs as compared to epithelial cells. Finally, iDCs infected with an HSV-1 LAT knockout mutant showed increased apoptosis when compared to iDCs infected with the corresponding wild-type HSV-1. Taken together, our results demonstrate that apoptosis of HSV-1-infected iDCs requires both c-FLIP downregulation and diminished expression of viral LAT.

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Infection of dendritic cells with herpes simplex virus type 1 induces rapid degradation of CYTIP, thereby modulating adhesion and migration

Blood ◽

10.1182/blood-2010-07-294363 ◽

2011 ◽

Vol 118 (1) ◽

pp. 107-115 ◽

Cited By ~ 20

Author(s):

Alexandros A. Theodoridis ◽

Christina Eich ◽

Carl G. Figdor ◽

Alexander Steinkasserer

Keyword(s):

Dendritic Cells ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

Immune Responses ◽

Virus Type ◽

Herpes Simplex Virus Type ◽

Lymphoid Tissues ◽

Simplex Virus ◽

Hsv 1

Abstract Immune responses require spatial and temporal coordinated interactions between different cell types within distinct microenvironments. This dynamic interplay depends on the competency of the involved cells, predominantly leukocytes, to actively migrate to defined sites of cellular encounters in various tissues. Because of their unique capacity to transport antigen from the periphery to secondary lymphoid tissues for the activation of naive T cells, dendritic cells (DCs) play a key role in the initiation and orchestration of adaptive immune responses. Therefore, pathogen-mediated interference with this process is a very effective way of immune evasion. CYTIP (cytohesin-interacting protein) is a key regulator of DC motility. It has previously been described to control LFA-1 deactivation and to regulate DC adherence. CYTIP expression is up-regulated during DC maturation, enabling their transition from the sessile to the motile state. Here, we demonstrate that on infection of human monocyte-derived DCs with herpes simplex virus type 1 (HSV-1), CYTIP is rapidly degraded and as a consequence β-2 integrins, predominantly LFA-1, are activated. Furthermore, we show that the impairment of migration in HSV-1-infected DCs is in part the result of this increased integrin-mediated adhesion. Thus, we propose a new mechanism of pathogen-interference with central aspects of leukocyte biology.

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Identification of Herpes Simplex Virus Type 1 Latency-Associated Transcript Sequences That both Inhibit Apoptosis and Enhance the Spontaneous Reactivation Phenotype

Journal of Virology ◽

10.1128/jvi.77.11.6556-6561.2003 ◽

2003 ◽

Vol 77 (11) ◽

pp. 6556-6561 ◽

Cited By ~ 44

Author(s):

Ling Jin ◽

Weiping Peng ◽

Guey-Chuen Perng ◽

David J. Brick ◽

Anthony B. Nesburn ◽

...

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Virus Type ◽

Herpes Simplex Virus Type ◽

Caspase 9 ◽

Induced Apoptosis ◽

Simplex Virus ◽

Spontaneous Reactivation ◽

Hsv 1

ABSTRACT The herpes simplex virus type 1 (HSV-1) latency-associated transcript (LAT) gene is essential for the high spontaneous and induced reactivation phenotype of HSV-1 in the rabbit ocular model and for the high induced reactivation phenotype in the mouse ocular model. Recently we showed that LAT has an antiapoptosis function, and we hypothesized that LAT's ability to inhibit apoptosis played an important role in LAT's ability to enhance the reactivation phenotype. Expression of just the first 1.5 kb of the 8.3-kb LAT gene is sufficient for both inhibition of apoptosis in an in vitro transient-transfection assay and the high spontaneous reactivation phenotype in vivo. Here we show the results of more complex mapping studies in which inhibition of apoptosis and the enhanced spontaneous reactivation phenotype also appear to be linked. The HSV-1 mutant virus dLAT371 has a high spontaneous reactivation phenotype in rabbits, suggesting that the LAT region deleted in this mutant (LAT nucleotides 76 to 447) is not required for this phenotype. The LAT3.3A viral mutant (which expresses LAT nucleotides 1 to 1499) also has a high spontaneous reactivation phenotype, suggesting that the region of LAT not expressed by this mutant (LAT nucleotide 1500 to the end of LAT) is also not required for this phenotype. Surprisingly, LAT2.9A, which is a combination of dLAT371 and LAT3.3A (i.e., it expresses LAT nucleotides 1 to 76 and 447 to 1499), has a low spontaneous reactivation phenotype indistinguishable from that of LAT null mutants. We report here that consistent with the low spontaneous reactivation phenotype of LAT2.9A, a plasmid expressing the identical LAT RNA did not inhibit caspase 9-induced apoptosis. In contrast, plasmids containing the same deletion but able to transcribe up to or past LAT nucleotide 2850 (rather than just up to LAT nucleotide 1499) inhibited caspase 9-induced apoptosis, consistent with the high spontaneous reactivation phenotype of dLAT371. Thus, LAT2.9A may have a low spontaneous reactivation phenotype because the LAT RNA that is made cannot block apoptosis, and dLAT371 apparently has a high spontaneous reactivation phenotype because the LAT RNA made has significant antiapoptosis activity. Furthermore, LAT appeared to have at least two regions capable of interfering with caspase 9-induced apoptosis. One region partially overlaps LAT nucleotides 76 to 447. The second region is partially (or completely) downstream of LAT nucleotide 1499.

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Infection of mature dendritic cells with herpes simplex virus type 1 dramatically reduces lymphoid chemokine-mediated migration

Journal of General Virology ◽

10.1099/vir.0.80852-0 ◽

2005 ◽

Vol 86 (6) ◽

pp. 1645-1657 ◽

Cited By ~ 62

Author(s):

Alexander T. Prechtel ◽

Nadine M. Turza ◽

Dieter J. Kobelt ◽

Jutta I. Eisemann ◽

Robert S. Coffin ◽

...

Keyword(s):

Dendritic Cells ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

Virus Type ◽

Herpes Simplex Virus Type ◽

Antiviral Immune Response ◽

Migration Assays ◽

Simplex Virus ◽

Hsv 1

Herpes simplex virus type 1 (HSV-1) is able to establish latency in infected individuals. In order to characterize potential new immune-escape mechanisms, mature dendritic cells (DCs) were infected with HSV-1 and total cellular RNA was isolated from infected and mock-infected populations at different time points. RNA profiling on Affymetrix Human Genome U133A arrays demonstrated a dramatic downregulation of the migration-mediating surface molecules CCR7 and CXCR4, an observation that was further confirmed by RT-PCR and fluorescence-activated cell sorting analyses. Furthermore, migration assays revealed that, upon infection of mature DCs, CCR7- and CXCR4-mediated migration towards the corresponding CCL19 and CXCL12 chemokine gradients was strongly reduced. It is noteworthy that the infection of immature DCs with HSV-1 prior to maturation led to a failure of CCR7 and CXCR4 upregulation during DC maturation and, as a consequence, also induced a block in their migratory capacity. Additional migration assays with a Δvhs mutant virus lacking the virion host shutoff (vhs) gene, which is known to degrade cellular mRNAs, suggested a vhs-independent mechanism. These results indicate that HSV-1-infected mature DCs are limited in their capacity to migrate to secondary lymphoid organs, the areas of antigen presentation and T-cell stimulation, thus inhibiting an antiviral immune response. This represents a novel, previously unrecognized mechanism for HSV-1 to escape the human immune system.

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Pharmacological Inhibition of IRE-1 Alpha Activity in Herpes Simplex Virus Type 1 and Type 2-Infected Dendritic Cells Enhances T Cell Activation

Frontiers in Immunology ◽

10.3389/fimmu.2021.764861 ◽

2022 ◽

Vol 12 ◽

Author(s):

Eduardo I. Tognarelli ◽

Angello Retamal-Díaz ◽

Mónica A. Farías ◽

Luisa F. Duarte ◽

Tomás F. Palomino ◽

...

Keyword(s):

Dendritic Cells ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

T Cell ◽

Virus Type ◽

Herpes Simplex Virus Type ◽

Simplex Virus ◽

Hsv 1

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infections are life-long and highly prevalent in the human population. These viruses persist in the host, eliciting either symptomatic or asymptomatic infections that may occur sporadically or in a recurrent manner through viral reactivations. Clinical manifestations due to symptomatic infection may be mild such as orofacial lesions, but may also translate into more severe diseases, such as ocular infections that may lead to blindness and life-threatening encephalitis. A key feature of herpes simplex viruses (HSVs) is that they have evolved molecular determinants that hamper numerous components of the host’s antiviral innate and adaptive immune system. Importantly, HSVs infect and negatively modulate the function of dendritic cells (DCs), by inhibiting their T cell-activating capacity and eliciting their apoptosis after infection. Previously, we reported that HSV-2 activates the splicing of the mRNA of XBP1, which is related to the activity of the unfolded protein response (UPR) factor Inositol-Requiring Enzyme 1 alpha (IRE-1α). Here, we sought to evaluate if the activation of the IRE-1α pathway in DCs upon HSV infection may be related to impaired DC function after infection with HSV-1 or HSV-2. Interestingly, the pharmacological inhibition of the endonuclease activity of IRE-1α in HSV-1- and HSV-2-infected DCs significantly reduced apoptosis in these cells and enhanced their capacity to migrate to lymph nodes and activate virus-specific CD4+ and CD8+ T cells. These findings suggest that the activation of the IRE-1α-dependent UPR pathway in HSV-infected DCs may play a significant role in the negative effects that these viruses exert over these cells and that the modulation of this signaling pathway may be relevant for enhancing the function of DCs upon infection with HSVs.

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Infectivity of herpes simplex virus type-1 (HSV-1) amplicon vectors in dendritic cells is determined by the helper virus strain used for packaging

Journal of Virological Methods ◽

10.1016/j.jviromet.2007.05.013 ◽

2007 ◽

Vol 145 (1) ◽

pp. 37-46 ◽

Cited By ~ 2

Author(s):

Kathlyn Santos ◽

Christine M. Sanfilippo ◽

Wade C. Narrow ◽

Ann E. Casey ◽

Sol M. Rodriguez-Colon ◽

...

Keyword(s):

Dendritic Cells ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

Virus Type ◽

Virus Strain ◽

Herpes Simplex Virus Type ◽

Helper Virus ◽

Simplex Virus ◽

Hsv 1

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Herpes Simplex Virus Type 1 Renders Infected Cells Resistant to Cytotoxic T-Lymphocyte-Induced Apoptosis

Journal of Virology ◽

10.1128/jvi.72.1.436-441.1998 ◽

1998 ◽

Vol 72 (1) ◽

pp. 436-441 ◽

Cited By ~ 73

Author(s):

Keith R. Jerome ◽

Jonathan F. Tait ◽

David M. Koelle ◽

Lawrence Corey

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Dna Fragmentation ◽

Immune Evasion ◽

Herpes Simplex Virus Type ◽

Infected Cells ◽

Induced Apoptosis ◽

Simplex Virus ◽

Hsv 1

ABSTRACT Many viruses interfere with apoptosis of infected cells, presumably preventing cellular apoptosis as a direct response to viral infection. Since cytotoxic T lymphocytes (CTL) induce apoptosis of infected cells as part of the “lethal hit,” inhibition of apoptosis could represent an effective immune evasion strategy. We report here herpes simplex virus type 1 (HSV-1) interference with CTL-induced apoptosis of infected cells and show that HSV-1 inhibits the nuclear manifestations of apoptosis but not the membrane changes. The HL-60 cell line (human promyelocytic leukemia) undergoes apoptosis in response to many stimuli, including incubation with ethanol. After HSV-1 infection (strains E115 and 17+), ethanol-treated cells did not produce oligonucleosomal DNA fragments characteristic of apoptosis, as assayed by gel electrophoresis and enzyme-linked immunosorbent assay. Inhibition was detected 2 h after infection and increased over time. Importantly, HSV-1-infected cells were resistant to apoptosis induced by antigen-specific CD4+ CTL, despite the fact that CTL recognition and degranulation in response to infected targets remained intact. Unlike HSV-1, HSV-2 (strains 333 and HG52) did not inhibit DNA fragmentation. In contrast to the inhibition of DNA fragmentation by HSV-1, none of the HSV-1 or -2 strains interfered with the ethanol-induced exposure of surface phosphatidylserine characteristic of apoptosis, as determined by annexin V binding. These results demonstrate that genes of HSV-1 inhibit the nuclear manifestations of apoptosis but not the membrane manifestations, suggesting that these may be mediated via separate pathways. They also suggest that HSV-1 inhibition of CTL-induced apoptosis may be an important mechanism of immune evasion.

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Role of Dendritic Cells in Enhancement of Herpes Simplex Virus Type 1 Latency and Reactivation in Vaccinated Mice

Clinical and Vaccine Immunology ◽

10.1128/cvi.00318-08 ◽

2008 ◽

Vol 15 (12) ◽

pp. 1859-1867 ◽

Cited By ~ 27

Author(s):

Kevin R. Mott ◽

Homayon Ghiasi

Keyword(s):

Dendritic Cells ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

Virus Type ◽

Herpes Simplex Virus Type ◽

Diphtheria Toxin ◽

Corneal Scarring ◽

Simplex Virus ◽

Hsv 1

ABSTRACT Ocular infection with herpes simplex virus type 1 (HSV-1) frequently leads to recurrent infection, which is a major cause of corneal scarring. Thus, the prevention of the establishment of latency should be a primary goal of vaccination against HSV-1. To this end, we have examined the contribution of dendritic cells (DCs) to the efficacy of a vaccine against ocular HSV-1 infection. Transgenic mice (expressing a CD11c-diphtheria toxin receptor-green fluorescent protein construct) with a BALB/c background were immunized with a vaccine consisting of DNA that encodes five HSV-1 glycoproteins or were immunized with vector control DNA. The vaccinated mice were then depleted of their DCs through the injection of diphtheria toxin before and after ocular challenge with HSV-1. Analyses of HSV-1 replication in the eye, blepharitis, corneal scarring, and the survival of the infected mice upon primary infection indicated that DC depletion neither promoted nor compromised the efficacy of the vaccine. In contrast, DC depletion was associated with an approximately fivefold reduction in the level of latent virus in the trigeminal ganglia (TGs) of latently infected mice, as well as a significant reduction in the reactivation rate of latent virus. The possibility that DCs enhance the latency of HSV-1 in the TGs of ocularly infected mice suggests for the first time that DCs, rather than acting as “immune saviors,” can exacerbate disease and compromise vaccine efficacy by enhancing viral latency and reactivation.

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Lymphoid-Related CD11c+ CD8α+ Dendritic Cells Are Involved in Enhancing Herpes Simplex Virus Type 1 Latency

Journal of Virology ◽

10.1128/jvi.00566-08 ◽

2008 ◽

Vol 82 (20) ◽

pp. 9870-9879 ◽

Cited By ~ 27

Author(s):

Kevin R. Mott ◽

David UnderHill ◽

Steven L. Wechsler ◽

Homayon Ghiasi

Keyword(s):

Dendritic Cells ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

Virus Type ◽

Herpes Simplex Virus Type ◽

Ex Vivo ◽

Macrophage Colony ◽

Simplex Virus ◽

Hsv 1

ABSTRACT The mechanism(s) by which herpes simplex virus type 1 (HSV-1) latency is established in neurons is not known. In this study, we examined the effect of dendritic cells (DCs) on the level of HSV-1 latency in trigeminal ganglia (TGs) of ocularly infected BALB/c and C57BL/6 mice. We found that immunization of wild-type mice with FMS-like tyrosine kinase 3 ligand (Flt3L) DNA, which increases the number of DCs, increased the amount of latency in infected mice. Conversely, depletion of DCs was associated with reduced latency. Latency was also significantly reduced in Flt3L−/− and CD8−/− mice. Interestingly, immunization of Flt3L−/− but not CD8−/− mice with Flt3L DNA increased latency. Transfer experiments using DCs expanded ex vivo with Flt3L or granulocyte-macrophage colony-stimulating factor suggested that increased latency was associated with the presence of lymphoid-related (CD11c+ CD8α+) DCs, while reduced latency was associated with myeloid-related (CD11c+ CD8α−) DCs. Modulation of DC numbers by Flt3L DNA immunization or depletion did not alter acute virus replication in the eye or TG or eye disease in ocularly infected mice. Our results suggest that CD11c+ CD8α+ DCs directly or indirectly increase the amount of HSV-1 latency in mouse TGs.

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Herpes Simplex Virus Type 1 Induces CD83 Degradation in Mature Dendritic Cells with Immediate-Early Kinetics via the Cellular Proteasome

Journal of Virology ◽

10.1128/jvi.02327-06 ◽

2007 ◽

Vol 81 (12) ◽

pp. 6326-6338 ◽

Cited By ~ 57

Author(s):

Mirko Kummer ◽

Nadine M. Turza ◽

Petra Muhl-Zurbes ◽

Matthias Lechmann ◽

Chris Boutell ◽

...

Keyword(s):

Dendritic Cells ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

Cell Surface ◽

Virus Type ◽

Herpes Simplex Virus Type ◽

Surface Expression ◽

Simplex Virus ◽

Hsv 1

ABSTRACT Mature dendritic cells (DCs) are the most potent antigen-presenting cells within the human immune system. However, Herpes simplex virus type 1 (HSV-1) is able to interfere with DC biology and to establish latency in infected individuals. In this study, we provide new insights into the mechanism by which HSV-1 disarms DCs by the manipulation of CD83, a functionally important molecule for DC activation. Fluorescence-activated cell sorter (FACS) analyses revealed a rapid downmodulation of CD83 surface expression within 6 to 8 h after HSV-1 infection, in a manner strictly dependent on viral gene expression. Soluble CD83 enzyme-linked immunosorbent assays, together with Western blot analysis, demonstrated that CD83 rapidly disappears from the cell surface after contact with HSV-1 by a mechanism that involves protein degradation rather than shedding of CD83 from the cell surface into the medium. Infection experiments with an ICP0 deletion mutant demonstrated an important role for this viral immediate-early protein during CD83 degradation, since this particular mutant strain leads to strongly reduced CD83 degradation. This hypothesis was further strengthened by cotransfection of plasmids expressing CD83 and ICP0 into 293T cells, which led to significantly reduced accumulation of CD83. In strong contrast, transfection of plasmids expressing CD83 and a mutant ICP0 defective in its RING finger-mediated E3 ubiquitin ligase function did not reduce CD83 expression. Inhibition of the proteasome, the cellular protein degradation machinery, almost completely restored CD83 surface expression during HSV-1 infection, indicating that proteasome-mediated degradation and HSV-1 ICP0 play crucial roles in this novel viral immune escape mechanism.

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Mature Dendritic Cells Infected with Herpes Simplex Virus Type 1 Exhibit Inhibited T-Cell Stimulatory Capacity

Journal of Virology ◽

10.1128/jvi.74.15.7127-7136.2000 ◽

2000 ◽

Vol 74 (15) ◽

pp. 7127-7136 ◽

Cited By ~ 206

Author(s):

Monika Kruse ◽

Olaf Rosorius ◽

Friedrich Krätzer ◽

Gerhard Stelz ◽

Christine Kuhnt ◽

...

Keyword(s):

Dendritic Cells ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

Immune Responses ◽

Herpes Simplex Virus Type ◽

Stimulatory Capacity ◽

Simplex Virus ◽

Cell Stimulatory Capacity ◽

Hsv 1

ABSTRACT Mature dendritic cells (DC) are the most potent antigen-presenting cells within the entire immune system. Interference with the function of these cells therefore constitutes a very powerful mechanism for viruses to escape immune responses. Several members of theHerpesviridae family have provided examples of such escape strategies, including interference with antigen presentation and production of homologous cytokines. In this study we investigated the infection of mature DC with herpes simplex virus type 1 (HSV-1) and the way in which infection alters the phenotype and function of mature DC. Interestingly, the T-cell-stimulatory capacity of these DC was strongly impaired. Furthermore, we demonstrated that HSV-1 leads to the specific degradation of CD83, a cell surface molecule which is specifically upregulated during DC maturation. These data indicate that HSV-1 has developed yet another novel mechanism to escape immune responses.

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