scholarly journals IRF-3 Activation by Sendai Virus Infection Is Required for Cellular Apoptosis and Avoidance of Persistence

2008 ◽  
Vol 82 (7) ◽  
pp. 3500-3508 ◽  
Author(s):  
Kristi Peters ◽  
Saurabh Chattopadhyay ◽  
Ganes C. Sen
Keyword(s):  
Virus Infection ◽  
Persistent Infection ◽  
Cellular Response ◽  
Sendai Virus ◽  
Virus Production ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Infected Cells ◽  
Jnk Activation ◽  
Human Parainfluenza Virus

ABSTRACT Here, we report that specific manipulations of the cellular response to virus infection can cause prevention of apoptosis and consequent establishment of persistent infection. Infection of several human cell lines with Sendai virus (SeV) or human parainfluenza virus 3, two prototypic paramyxoviruses, caused slow apoptosis, which was markedly accelerated upon blocking the action of phosphatidylinositol 3-kinases (PI3 kinases) in the infected cells. The observed apoptosis required viral gene expression and the action of the caspase 8 pathway. Although virus infection activated PI3 kinase, as indicated by AKT activation, its blockage did not inhibit JNK activation or IRF-3 activation. The action of neither the Jak-STAT pathway nor the NF-κB pathway was required for apoptosis. In contrast, IRF-3 activation was essential, although induction of the proapototic protein TRAIL by IRF-3 was not required. When IRF-3 was absent or its activation by the RIG-I pathway was blocked, SeV established persistent infection, as documented by viral protein production and infectious virus production. Introduction of IRF-3 in the persistently infected cells restored the cells' ability to undergo apoptosis. These results demonstrated that in our model system, IRF-3 controlled the fate of the SeV-infected cells by promoting apoptosis and preventing persistence.

scholarly journals Adenovirus Virus-Associated RNA Is Processed to Functional Interfering RNAs Involved in Virus Production

2006 ◽  
Vol 80 (3) ◽  
pp. 1376-1384 ◽  
Author(s):  
Oscar Aparicio ◽  
Nerea Razquin ◽  
Mikel Zaratiegui ◽  
Iñigo Narvaiza ◽  
Puri Fortes
Keyword(s):  
Gene Expression ◽  
Virus Production ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Small Interfering Rnas ◽  
Control Of Gene Expression ◽  
Posttranscriptional Gene Silencing ◽  
Argonaute 2 ◽  
Complementary Sequences ◽  
Infected Cells

ABSTRACT Posttranscriptional gene silencing allows sequence-specific control of gene expression. Specificity is guaranteed by small antisense RNAs such as microRNAs (miRNAs) or small interfering RNAs (siRNAs). Functional miRNAs derive from longer double-stranded RNA (dsRNA) molecules that are cleaved to pre-miRNAs in the nucleus and are transported by exportin 5 (Exp 5) to the cytoplasm. Adenovirus-infected cells express virus-associated (VA) RNAs, which are dsRNA molecules similar in structure to pre-miRNAs. VA RNAs are also transported by Exp 5 to the cytoplasm, where they accumulate. Here we show that small RNAs derived from VA RNAs (svaRNAs), similar to miRNAs, can be found in adenovirus-infected cells. VA RNA processing to svaRNAs requires neither viral replication nor viral protein expression, as evidenced by the fact that svaRNA accumulation can be detected in cells transfected with VA sequences. svaRNAs are efficiently bound by Argonaute 2, the endonuclease of the RNA-induced silencing complex, and behave as functional siRNAs, in that they inhibit the expression of reporter genes with complementary sequences. Blocking svaRNA-mediated inhibition affects efficient adenovirus production, indicating that svaRNAs are required for virus viability. Thus, svaRNA-mediated silencing could represent a novel mechanism used by adenoviruses to control cellular or viral gene expression.

scholarly journals Single-cell RNA-sequencing of Herpes simplex virus 1-infected cells identifies NRF2 activation as an antiviral program

2019 ◽  
Author(s):  
Emanuel Wyler ◽  
Vedran Franke ◽  
Jennifer Menegatti ◽  
Kocks Christine ◽  
Anastasiya Boltengagen ◽  
...  
Keyword(s):  
Host Cell ◽  
Transition Probabilities ◽  
Virus Production ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Herpes Simplex Virus 1 ◽  
Nrf2 Activation ◽  
Analysis Scheme ◽  
Infected Cells ◽  
Hsv 1

AbstractHerpesvirus infection initiates a range of perturbations in the host cell, which remain poorly understood at the level of individual cells. Here, we quantified the transcrips of single human primary fibroblasts during the first hours of lytic infection with HSV-1. By applying a generalizable analysis scheme, we defined a precise temporal order of early viral gene expression and found unexpected bifurcations and bottlenecks. We identified individual host cell genes and pathways relevant in early infection by combining three different computational approaches: gene and pathway overdispersion analysis, prediction of cell-state transition probabilities as well as future cell states. One transcriptional program, which was turned on in infected cells and correlated with increased resistance to infection, implicated the transcription factor NRF2. Consequently, Bardoxolone methyl, a known NRF2 agonist, impaired virus production, suggesting that NRF2 activation restricts the progression of viral infection. Our study provides novel insights into early stages of HSV-1 infection and serves as a general blueprint for the investigation of heterogenous cell states in virus infection.

scholarly journals Early Stage of Establishment of Persistent Sendai Virus Infection: Unstable Dynamic Phase and Then Selection of Viruses Which Are Tightly Cell Associated, Temperature Sensitive, and Capable of Establishing Persistent Infection

2004 ◽  
Vol 78 (21) ◽  
pp. 11939-11951 ◽  
Author(s):  
Morihiro Ito ◽  
Taijiro Takeuchi ◽  
Machiko Nishio ◽  
Mitsuo Kawano ◽  
Hiroshi Komada ◽  
...  
Keyword(s):  
Virus Infection ◽  
Cell Lines ◽  
Temperature Sensitivity ◽  
Persistent Infection ◽  
Sendai Virus ◽  
Early Stage ◽  
Persistently Infected ◽  
Dynamic Phase ◽  
M Proteins ◽  
Infected Cells

ABSTRACT We obtained 157 cloned cell lines persistently infected with Sendai virus; these cell lines were generated independently of each other. Infectious viruses could be isolated from 123 of these cloned cell lines by inoculation of culture fluids or infected cells into embryonated eggs. The majority of the viruses carried by cells persistently infected with viruses showed high cytotoxicity and did not have the ability to establish persistent infection. The association of carried virus with cells became stronger and virus isolation correspondingly became more difficult as cells persistently infected with virus were subcultured. Viruses derived from virus-infected cells eventually acquired the ability to establish persistent infection, although the ways in which the viruses acquired this ability varied. The viruses also acquired temperature sensitivity as persistently infected cells were subcultured. First, the hemagglutinin-neuraminidase and M proteins acquired temperature sensitivity, and then the polymerase(s) did so. The M proteins were localized in the nuclei of cells infected with cloned viruses that had the ability to establish persistent infection. Cells infected with viruses capable of establishing persistent infection showed no or slight staining by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling. Specific amino acid substitutions accumulated in the M protein and the L protein as virus-infected cells were subcultured. This study shows that there is an unstable dynamic phase at an early stage of the establishment of persistent Sendai virus infection (steady state), and then viruses capable of establishing persistent infection are selected.

scholarly journals Redefining De Novo Gammaherpesvirus Infection Through High-Dimensional, Single-Cell Analysis of Virus and Host

2020 ◽  
Author(s):  
Jennifer N. Berger ◽  
Bridget Sanford ◽  
Abigail K. Kimball ◽  
Lauren M. Oko ◽  
Rachael E. Kaspar ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virus Infection ◽  
Single Cell ◽  
Single Cell Analysis ◽  
De Novo ◽  
Viral Gene Expression ◽  
High Dimensional ◽  
Viral Gene ◽  
Cell Analysis ◽  
Infected Cells

SUMMARYVirus infection is frequently characterized using bulk cell populations. How these findings correspond to infection in individual cells remains unclear. Here, we integrate high-dimensional single-cell approaches to quantify viral and host RNA and protein expression signatures using de novo infection with a well-characterized model gammaherpesvirus. While infected cells demonstrated genome-wide transcription, individual cells revealed pronounced variation in gene expression, with only 9 of 80 annotated viral open reading frames uniformly expressed in all cells, and a 1000-fold variation in viral RNA expression between cells. Single-cell analysis further revealed positive and negative gene correlations, many uniquely present in a subset of cells. Beyond variation in viral gene expression, individual cells demonstrated a pronounced, dichotomous signature in host gene expression, revealed by measuring host RNA abundance and post-translational protein modifications. These studies provide a resource for the high-dimensional analysis of virus infection, and a conceptual framework to define virus infection as the sum of virus and host responses at the single-cell level.HIGHLIGHTSCyTOF and scRNA-seq identify wide variation in gene expression between infected cells.Host RNA expression and post-translational modifications stratify virus infection.Single cell RNA analysis reveals new relationships in viral gene expression.Simultaneous measurement of virus and host defines distinct infection states.

scholarly journals Dicer is involved in protection against influenza A virus infection

2007 ◽  
Vol 88 (10) ◽  
pp. 2627-2635 ◽  
Author(s):  
Alexey A. Matskevich ◽  
Karin Moelling
Keyword(s):  
Virus Infection ◽  
Influenza A Virus ◽  
Mammalian Cells ◽  
Influenza A ◽  
Virus Production ◽  
Vero Cells ◽  
Antiviral Response ◽  
Protein Levels ◽  
Infected Cells ◽  
Influenza A Virus Infection

In mammals the interferon (IFN) system is a central innate antiviral defence mechanism, while the involvement of RNA interference (RNAi) in antiviral response against RNA viruses is uncertain. Here, we tested whether RNAi is involved in the antiviral response in mammalian cells. To investigate the role of RNAi in influenza A virus-infected cells in the absence of IFN, we used Vero cells that lack IFN-α and IFN-β genes. Our results demonstrate that knockdown of a key RNAi component, Dicer, led to a modest increase of virus production and accelerated apoptosis of influenza A virus-infected cells. These effects were much weaker in the presence of IFN. The results also show that in both Vero cells and the IFN-producing alveolar epithelial A549 cell line influenza A virus targets Dicer at mRNA and protein levels. Thus, RNAi is involved in antiviral response, and Dicer is important for protection against influenza A virus infection.

scholarly journals Patterns of accumulation of miRNAs encoded by herpes simplex virus during productive infection, latency, and on reactivation

2014 ◽  
Vol 112 (1) ◽  
pp. E49-E55 ◽  
Author(s):  
Te Du ◽  
Zhiyuan Han ◽  
Guoying Zhou ◽  
Bernard Roizman
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Cultured Cells ◽  
Viral Gene Expression ◽  
The Body ◽  
Productive Infection ◽  
Viral Gene ◽  
Infected Cells ◽  
Simplex Virus ◽  
Portal Of Entry

The key events in herpes simplex virus (HSV) infections are (i) replication at a portal of entry into the body modeled by infection of cultured cells; (ii) establishment of a latent state characterized by a sole latency-associated transcript and microRNAs (miRNAs) modeled in murine peripheral ganglia 30 d after inoculation; and (iii) reactivation from the latent state modeled by excision and incubation of ganglia in medium containing anti-NGF antibody for a timespan of a single viral replicative cycle. In this report, we examine the pattern of synthesis and accumulation of 18 HSV-1 miRNAs in the three models. We report the following: (i) H2-3P, H3-3P, H4-3P, H5-3P, H6-3P, and H7-5P accumulated in ganglia harboring latent virus. All but H4-3P were readily detected in productively infected cells, and most likely they originate from three transcriptional units. (ii) H8-5P, H15, H17, H18, H26, and H27 accumulated during reactivation. Of this group, only H26 and H27 could be detected in productively infected cells. (iii) Of the 18 we have examined, only 10 miRNAs were found to accumulate above background levels in productively infected cells. The disparity in the accumulation of miRNAs in cell culture and during reactivation may reflect differences in the patterns of regulation of viral gene expression during productive infection and during reactivation from the latent state.

scholarly journals Effects of inducing or inhibiting apoptosis on Sindbis virus replication in mosquito cells

2008 ◽  
Vol 89 (11) ◽  
pp. 2651-2661 ◽  
Author(s):  
Hua Wang ◽  
Carol D. Blair ◽  
Ken E. Olson ◽  
Rollie J. Clem
Keyword(s):  
Virus Replication ◽  
Persistent Infection ◽  
Sindbis Virus ◽  
Actinomycin D ◽  
Virus Production ◽  
Cell Types ◽  
Lytic Infection ◽  
Mosquito Cells ◽  
Infected Cells ◽  
Apoptotic Genes

Sindbis virus (SINV) is a mosquito-borne virus in the genus Alphavirus, family Togaviridae. Like most alphaviruses, SINVs exhibit lytic infection (apoptosis) in many mammalian cell types, but are generally thought to cause persistent infection with only moderate cytopathic effects in mosquito cells. However, there have been several reports of apoptotic-like cell death in mosquitoes infected with alphaviruses or flaviviruses. Given that apoptosis has been shown to be an antiviral response in other systems, we have constructed recombinant SINVs that express either pro-apoptotic or anti-apoptotic genes in order to test the effects of inducing or inhibiting apoptosis on SINV replication in mosquito cells. Recombinant SINVs expressing the pro-apoptotic genes reaper (rpr) from Drosophila or michelob_x (mx) from Aedes aegypti caused extensive apoptosis in cells from the mosquito cell line C6/36, thus changing the normal persistent infection observed with SINV to a lytic infection. Although the infected cells underwent apoptosis, high levels of virus replication were still observed during the initial infection. However, virus production subsequently decreased compared with persistently infected cells, which continued to produce high levels of virus over the next several days. Infection of C6/36 cells with SINV expressing the baculovirus caspase inhibitor P35 inhibited actinomycin D-induced caspase activity and protected infected cells from actinomycin D-induced apoptosis, but had no observable effect on virus replication. This study is the first to test directly whether inducing or inhibiting apoptosis affects arbovirus replication in mosquito cells.

Protein-RNA interactome analysis reveals wide association of KSHV ORF57 with host non-coding RNAs and polysomes

2021 ◽  
Author(s):  
Beatriz Alvarado-Hernandez ◽  
Yanping Ma ◽  
Nishi R. Sharma ◽  
Vladimir Majerciak ◽  
Alexei Lobanov ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Splicing ◽  
Rna Binding ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
28S Rrna ◽  
Protein Coding ◽  
Infected Cells ◽  
Non Coding Rnas ◽  
Rna Interaction

Kaposi’s sarcoma-associated herpesvirus (KSHV) ORF57 is an RNA-binding post-transcriptional regulator. We recently applied an affinity-purified anti-ORF57 antibody to conduct ORF57-CLIP (Cross-linking Immunoprecipitation) in combination with RNA-sequencing (CLIP-seq) and analyzed the genome-wide host RNA transcripts in association with ORF57 in BCBL-1 cells with lytic KSHV infection. Mapping of the CLIPed RNA reads to the human genome (GRCh37) revealed that most of the ORF57-associated RNA reads were from rRNAs. The remaining RNA reads mapped to several classes of host non-coding and protein-coding mRNAs. We found ORF57 binds and regulates expression of a subset of host lncRNAs, including LINC00324, LINC00355, and LINC00839 which are involved in cell growth. ORF57 binds snoRNAs responsible for 18S and 28S rRNA modifications, but does not interact with fibrillarin and NOP58. We validated ORF57 interactions with 67 snoRNAs by ORF57-RNA immunoprecipitation (RIP)-snoRNA-array assays. Most of the identified ORF57 rRNA binding sites (BS) overlap with the sites binding snoRNAs. We confirmed ORF57-snoRA71B RNA interaction in BCBL-1 cells by ORF57-RIP and Northern blot analyses using a 32 P-labeled oligo probe from the 18S rRNA region complementary to snoRA71B. Using RNA oligos from the rRNA regions that ORF57 binds for oligo pulldown-Western blot assays, we selectively verified ORF57 interactions with 5.8S and 18S rRNAs. Polysome profiling revealed that ORF57 associates with both monosomes and polysomes and its association with polysomes increases PABPC1 binding to, but prevent Ago2 from polysomes. Our data indicate a functional correlation with ORF57 binding and suppression of Ago2 activities for ORF57 promotion of gene expression. Significance As an RNA-binding protein, KSHV ORF57 regulates RNA splicing, stability, and translation and inhibits host innate immunity by blocking the formation of RNA granules in virus infected cells. In this report, ORF57 was found to interact many host non-coding RNAs, including lncRNAs, snoRNAs and ribosomal RNAs to carry out additional unknown functions. ORF57 binds a group of lncRNAs via the identified RNA motifs by ORF57 CLIP-seq to regulate their expression. ORF57 associates with snoRNAs independently of fibrillarin and NOP58 proteins, and with ribosomal RNA in the regions that commonly bind snoRNAs. Knockdown of fibrillarin expression decreases the expression of snoRNAs and CDK4, but not affect viral gene expression. More importantly, we found that ORF57 binds translationally active polysomes and enhances PABPC-1 but prevents Ago2 association with polysomes. Data provide a compelling evidence on how ORF57 in KSHV infected cells might regulate protein synthesis by blocking Ago2’s hostile activities on translation.

scholarly journals The Immune Evasion Paradox: Immunoevasins of Murine Cytomegalovirus Enhance Priming of CD8 T Cells by Preventing Negative Feedback Regulation

2008 ◽  
Vol 82 (23) ◽  
pp. 11637-11650 ◽  
Author(s):  
Verena Böhm ◽  
Christian O. Simon ◽  
Jürgen Podlech ◽  
Christof K. Seckert ◽  
Dorothea Gendig ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
T Cell ◽  
Negative Feedback ◽  
Cd8 T Cells ◽  
Viral Gene Expression ◽  
Cd8 T Cell ◽  
Murine Cytomegalovirus ◽  
Viral Gene ◽  
Infected Cells

ABSTRACT Cytomegaloviruses express glycoproteins that interfere with antigen presentation to CD8 T cells. Although the molecular modes of action of these “immunoevasins” differ between cytomegalovirus species, the convergent biological outcome is an inhibition of the recognition of infected cells. In murine cytomegalovirus, m152/gp40 retains peptide-loaded major histocompatibility complex class I molecules in a cis-Golgi compartment, m06/gp48 mediates their vesicular sorting for lysosomal degradation, and m04/gp34, although not an immunoevasin in its own right, appears to assist in the concerted action of all three molecules. Using the Ld-restricted IE1 epitope YPHFMPTNL in the BALB/c mouse model as a paradigm, we provide here an explanation for the paradox that immunoevasins enhance CD8 T-cell priming although they inhibit peptide presentation in infected cells. Adaptive immune responses are initiated in the regional lymph node (RLN) draining the site of pathogen exposure. In particular for antigens that are not virion components, the magnitude of viral gene expression providing the antigens is likely a critical parameter in priming efficacy. We have therefore focused on the events in the RLN and have related priming to intranodal viral gene expression. We show that immunoevasins enhance priming by downmodulating an early CD8 T-cell-mediated “negative feedback” control of the infection in the cortical region of the RLN, thus supporting the model that immunoevasins improve antigen supply for indirect priming by uninfected antigen-presenting cells. As an important consequence, these findings predict that deletion of immunoevasin genes in a replicative vaccine virus is not a favorable option but may, rather, be counterproductive.

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