scholarly journals Point Mutations in Herpes Simplex Virus Type 1 oriL, but Not in oriS, Reduce Pathogenesis during Acute Infection of Mice and Impair Reactivation from Latency

2006 ◽  
Vol 80 (1) ◽  
pp. 440-450 ◽  
Author(s):  
John W. Balliet ◽  
Priscilla A. Schaffer

ABSTRACT In vitro studies of herpes simplex virus type 1 (HSV-1) viruses containing mutations in core sequences of the viral origins of DNA replication, oriL and oriS, that eliminate the ability of these origins to initiate viral-DNA synthesis have demonstrated little or no effect on viral replication in cultured cells, leading to the conclusion that the two types of origins are functionally redundant. It remains unclear, therefore, why origins that appear to be redundant are maintained evolutionarily in HSV-1 and other neurotropic alphaherpesviruses. To test the hypothesis that oriL and oriS have distinct functions in the HSV-1 life cycle in vivo, we determined the in vivo phenotypes of two mutant viruses, DoriL-ILR and DoriS-I, containing point mutations in oriL and oriS site I, respectively, that eliminate origin DNA initiation function. Following corneal inoculation of mice, tear film titers of DoriS-I were reduced relative to wild-type virus. In all other tests, however, DoriS-I behaved like wild-type virus. In contrast, titers of DoriL-ILR in tear film, trigeminal ganglia (TG), and hindbrain were reduced and mice infected with DoriL-ILR exhibited greatly reduced mortality relative to wild-type virus. In the TG explant and TG cell culture models of reactivation, DoriL-ILR reactivated with delayed kinetics and, in the latter model, with reduced efficiency relative to wild-type virus. Rescuant viruses DoriL-ILR-R and DoriS-I-R behaved like wild-type virus in all tests. These findings demonstrate that functional differences exist between oriL and oriS and reveal a prominent role for oriL in HSV-1 pathogenesis.

2001 ◽  
Vol 75 (19) ◽  
pp. 9029-9036 ◽  
Author(s):  
Homayon Ghiasi ◽  
Yanira Osorio ◽  
Guey-Chuen Perng ◽  
Anthony B. Nesburn ◽  
Steven L. Wechsler

ABSTRACT The effect of interleukin-4 (IL-4) on herpes simplex virus type 1 (HSV-1) infection in mice was evaluated by construction of a recombinant HSV-1 expressing the gene for murine IL-4 in place of the latency-associated transcript (LAT). The mutant virus (HSV-IL-4) expressed high levels of IL-4 in cultured cells. The replication of HSV-IL-4 in tissue culture and in trigeminal ganglia was similar to that of wild-type virus. In contrast, HSV-IL-4 appeared to replicate less well in mouse eyes and brains. Although BALB/c mice are highly susceptible to HSV-1 infection, ocular infection with HSV-IL-4 resulted in 100% survival. Furthermore, 57% of the mice survived coinfection with a mixture of HSV-IL-4 and a lethal dose of wild-type McKrae, compared with only 10% survival following infection with McKrae alone. Similar to wild-type BALB/c mice, 100% of IL-4−/− mice also survived HSV-IL-4 infection. T-cell depletion studies suggested that protection against HSV-IL-4 infection was mediated by a CD4+-T-cell response.


1998 ◽  
Vol 72 (7) ◽  
pp. 5351-5359 ◽  
Author(s):  
Thandavarayan Nagashunmugam ◽  
John Lubinski ◽  
Liyang Wang ◽  
Lester T. Goldstein ◽  
Benjamin S. Weeks ◽  
...  

ABSTRACT Herpes simplex virus (HSV) glycoproteins gE and gI form an immunoglobulin G (IgG) Fc receptor (FcγR) that binds the Fc domain of human anti-HSV IgG and inhibits Fc-mediated immune functions in vitro. gE or gI deletion mutant viruses are avirulent, probably because gE and gI are also involved in cell-to-cell spread. In an effort to modify FcγR activity without affecting other gE functions, we constructed a mutant virus, NS-gE339, that has four amino acids inserted into gE within the domain homologous to mammalian IgG FcγRs. NS-gE339 expresses gE and gI, is FcγR−, and does not participate in antibody bipolar bridging since it does not block activities mediated by the Fc domain of anti-HSV IgG. In vivo studies were performed with mice because the HSV-1 FcγR does not bind murine IgG; therefore, the absence of an FcγR should not affect virulence in mice. NS-gE339 causes disease at the skin inoculation site comparably to wild-type and rescued viruses, indicating that the FcγR− mutant virus is pathogenic in animals. Mice were passively immunized with human anti-HSV IgG and then infected with mutant or wild-type virus. We postulated that the HSV-1 FcγR should protect wild-type virus from antibody attack. Human anti-HSV IgG greatly reduced viral titers and disease severity in NS-gE339-infected animals while having little effect on wild-type or rescued virus. We conclude that the HSV-1 FcγR enables the virus to evade antibody attack in vivo, which likely explains why antibodies are relatively ineffective against HSV infection.


2006 ◽  
Vol 80 (15) ◽  
pp. 7600-7612 ◽  
Author(s):  
Tracy Jo Pasieka ◽  
Tracey Baas ◽  
Victoria S. Carter ◽  
Sean C. Proll ◽  
Michael G. Katze ◽  
...  

ABSTRACTHerpes simplex virus type 1 (HSV-1) mutants lacking the ICP34.5 gene are severely attenuated in mouse models and have a significant growth defect in confluent mouse embryo fibroblasts. Previously, ICP34.5 was demonstrated to have a crucial role in evading the innate immune response to infection by mediating the dephosphorylation of eIF2α, a translation initiation factor phosphorylated by PKR during the antiviral response. To further understand the role of ICP34.5 in evasion of the antiviral response, we used transcriptional profiling to examine host cell gene expression in both wild-type and ICP34.5-null virus-infected mouse embryo fibroblasts over a time course of infection. Our study revealed that cells responded to infection within 3 h through PKR-dependent eIF2α phosphorylation and that the majority of up-regulated genes at 3 h postinfection were involved in the antiviral response. HSV-1 counters this response through early expression of ICP34.5 and dephosphorylation of eIF2α. By 12 h postinfection, the differences between the number and functional classification of genes differentially up- and down-regulated between wild-type and ICP34.5-null virus-infected cells were maximal. Specifically, in wild-type virus-infected cells, the majority of changed genes were involved in metabolic and biosynthetic processes, while in ICP34.5-null virus-infected cells, mostly antiviral genes were up-regulated. Further, ICP34.5-null virus-infected cells produced greater amounts of beta interferon than wild-type virus-infected cells. These results indicate that ICP34.5 expression and function at early times postinfection have a pivotal role in the ability of HSV-1 to gain control of the host cell and maintain an environment for successful viral replication.


2007 ◽  
Vol 81 (13) ◽  
pp. 6817-6826 ◽  
Author(s):  
Kening Wang ◽  
Gowtham Mahalingam ◽  
Susan E. Hoover ◽  
Erik K. Mont ◽  
Steven M. Holland ◽  
...  

ABSTRACT Mutations in the thymidine kinase gene (tk) of herpes simplex virus type 1 (HSV-1) explain most cases of virus resistance to acyclovir (ACV) treatment. Mucocutaneous lesions of patients with ACV resistance contain mixed populations of tk mutant and wild-type virus. However, it is unknown whether human ganglia also contain mixed populations since the replication of HSV tk mutants in animal neurons is impaired. Here we report the detection of mutated HSV tk sequences in human ganglia. Trigeminal and dorsal root ganglia were obtained at autopsy from an immunocompromised woman with chronic mucocutaneous infection with ACV-resistant HSV-1. The HSV-1 tk open reading frames from ganglia were amplified by PCR, cloned, and sequenced. tk mutations were detected in a seven-G homopolymer region in 11 of 12 ganglia tested, with clonal frequencies ranging from 4.2 to 76% HSV-1 tk mutants per ganglion. In 8 of 11 ganglia, the mutations were heterogeneous, varying from a deletion of one G to an insertion of one to three G residues, with the two-G insertion being the most common. Each ganglion had its own pattern of mutant populations. When individual neurons from one ganglion were analyzed by laser capture microdissection and PCR, 6 of 14 HSV-1-positive neurons were coinfected with HSV tk mutants and wild-type virus, 4 of 14 were infected with wild-type virus alone, and 4 of 14 were infected with tk mutant virus alone. These data suggest that diverse tk mutants arise independently under drug selection and establish latency in human sensory ganglia alone or together with wild-type virus.


2000 ◽  
Vol 74 (21) ◽  
pp. 10041-10054 ◽  
Author(s):  
Lisa E. Pomeranz ◽  
John A. Blaho

ABSTRACT VP22, the 301-amino-acid phosphoprotein product of the herpes simplex virus type 1 (HSV-1) UL49 gene, is incorporated into the tegument during virus assembly. We previously showed that highly modified forms of VP22 are restricted to infected cell nuclei (L. E. Pomeranz and J. A. Blaho, J. Virol. 73:6769–6781, 1999). VP22 packaged into infectious virions appears undermodified, and nuclear- and virion-associated forms are easily differentiated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (J. A. Blaho, C. Mitchell, and B. Roizman, J. Biol. Chem. 269:17401–17410, 1994). As VP22 packaging-associated undermodification is unique among HSV-1 tegument proteins, we sought to determine the role of VP22 during viral replication. We now show the following. (i) VP22 modification occurs in the absence of other viral factors in cell lines which stably express its gene. (ii) RF177, a recombinant HSV-1 strain generated for this study, synthesizes only the amino-terminal 212 amino acids of VP22 (Δ212). (iii) Δ212 localizes to the nucleus and incorporates into virions during RF177 infection of Vero cells. Thus, the carboxy-terminal region is not required for nuclear localization of VP22. (iv) RF177 synthesizes the tegument proteins VP13/14, VP16, and VHS (virus host shutoff) and incorporates them into infectious virions as efficiently as wild-type virus. However, (v) the loss of VP22 in RF177 virus particles is compensated for by a redistribution of minor virion components. (vi) Mature RF177 virions are identical to wild-type particles based on electron microscopic analyses. (vii) Single-step growth kinetics of RF177 in Vero cells are essentially identical to those of wild-type virus. (viii) RF177 plaque size is reduced by nearly 40% compared to wild-type virus. Based on these results, we conclude that VP22 is not required for tegument formation, virion assembly/maturation, or productive HSV-1 replication, while the presence of full-length VP22 in the tegument is needed for efficient virus spread in Vero cell monolayers.


2002 ◽  
Vol 76 (16) ◽  
pp. 8090-8100 ◽  
Author(s):  
Helen L. Attrill ◽  
Sarah A. Cumming ◽  
J. Barklie Clements ◽  
Sheila V. Graham

ABSTRACT The US11 protein of herpes simplex virus type 1 (HSV-1) is a small, highly basic phosphoprotein expressed at late times during infection. US11 localizes to the nucleolus in infected cells, can associate with ribosomes, and has been shown to bind RNA. The RNA substrates of US11 identified thus far have no apparent role in the virus lytic cycle, so we set out to identify a novel, biologically relevant RNA substrate(s) for this protein in HSV-1-infected cells. We designed a reverse transcriptase PCR-based protocol that allowed specific selection of a 600-bp RNA binding partner for US11. This RNA sequence, designated 12/14, is present in the coterminal HSV-1 mRNAs UL12, UL13, and UL14. We show that the binding of US11 to 12/14 is sequence-specific and mediated by the C-terminal domain of the protein. To elucidate the role of US11 in the virus life cycle, we infected cells with wild-type virus, a cosmid-reconstructed US11 HSV-1 null mutant, and a cosmid-reconstructed wild-type virus and analyzed expression of UL12, -13, and -14 during a time course of infection. These experiments revealed that this interaction has biological activity; at early times of infection, US11 down-regulates UL13 protein kinase mRNA and protein.


2000 ◽  
Vol 74 (8) ◽  
pp. 3909-3917 ◽  
Author(s):  
Francesca Cocchi ◽  
Laura Menotti ◽  
Patrice Dubreuil ◽  
Marc Lopez ◽  
Gabriella Campadelli-Fiume

ABSTRACT The immunoglobulin-like receptors that mediate entry of herpes simplex virus type 1 (HSV-1) into human cells were found to mediate the direct cell-to-cell spread of wild-type virus. The receptors here designated Nectin1α and -δ and Nectin2α were originally designated HIgR, PRR1/HveC, and PRR2α/HveB, respectively. We report the following. (i) Wild-type HSV-1 spreads from cell to cell in J cells expressing nectin1α or nectin1δ but not in parental J cells that are devoid of entry receptors. A monoclonal antibody to nectin1, which blocks entry, also blocked cell-to-cell spread in nectin1-expressing J cells. Moreover, wild-type virus did not spread from a receptor-positive to a receptor-negative cell. (ii) The antibody to nectin1 blocked transmission of wild-type virus in a number of human cell lines, with varying efficiencies, suggesting that nectin1 is the principal mediator of wild-type virus spread in a variety of human cell lines. (iii) Nectin1 did not mediate cell fusion induced by the syncytial strains HSV-1(MP) and HFEM-syn. (iv) Nectin2α could serve as a receptor for spread of a mutant virus carrying the L25P substitution in glycoprotein D, but not of wild-type virus, in agreement with its ability to mediate entry of the mutant but not of wild-type virus.


2008 ◽  
Vol 82 (12) ◽  
pp. 6052-6055 ◽  
Author(s):  
Tracy Jo Pasieka ◽  
Betty Lu ◽  
David A. Leib

ABSTRACT Mice lacking the Stat1 interferon signaling gene were infected with herpes simplex virus type 1 (HSV-1) or an attenuated recombinant lacking virion host shutoff (Δvhs). Δvhs virus-infected Stat1−/− mice showed levels of replication equivalent to that of the wild-type virus-infected control mice but reduced relative to wild-type virus-infected Stat1−/− mice. Stat1 deficiency relieves the immunomodulatory deficiency of Δvhs virus, but not its inherent growth defect. Also Vhs is dispensable for reactivation.


1998 ◽  
Vol 72 (5) ◽  
pp. 3779-3788 ◽  
Author(s):  
Brandy Salmon ◽  
Charles Cunningham ◽  
Andrew J. Davison ◽  
Wendy J. Harris ◽  
Joel D. Baines

ABSTRACT Previous studies have suggested that the UL17 gene of herpes simplex virus type 1 (HSV-1) is essential for virus replication. In this study, viral mutants incorporating either a lacZexpression cassette in place of 1,490 bp of the 2,109-bp UL17 open reading frame [HSV-1(ΔUL17)] or a DNA oligomer containing an in-frame stop codon inserted 778 bp from the 5′ end of the UL17 open reading frame [HSV-1(UL17-stop)] were plaque purified on engineered cell lines containing the UL17 gene. A virus derived from HSV-1(UL17-stop) but containing a restored UL17 gene was also constructed and was designated HSV-1(UL17-restored). The latter virus formed plaques and cleaved genomic viral DNA in a manner indistinguishable from wild-type virus. Neither HSV-1(ΔUL17) nor HSV-1(UL17-stop) formed plaques or produced infectious progeny when propagated on noncomplementing Vero cells. Furthermore, genomic end-specific restriction fragments were not detected in DNA purified from noncomplementing cells infected with HSV-1(ΔUL17) or HSV-1(UL17-stop), whereas end-specific fragments were readily detected when the viruses were propagated on complementing cells. Electron micrographs of thin sections of cells infected with HSV-1(ΔUL17) or HSV-1(UL17-stop) illustrated that empty capsids accumulated in the nuclei of Vero cells, whereas DNA-containing capsids accumulated in the nuclei of complementing cells and enveloped virions were found in the cytoplasm and extracellular space. Additionally, protein profiles of capsids purified from cells infected with HSV-1(ΔUL17) compared to wild-type virus show no detectable differences. These data indicate that the UL17 gene is essential for virus replication and is required for cleavage and packaging of viral DNA. To characterize the UL17 gene product, an anti-UL17 rabbit polyclonal antiserum was produced. The antiserum reacted strongly with a major protein of apparent M r 77,000 and weakly with a protein of apparent M r 72,000 in wild-type infected cell lysates and in virions. Bands of similar sizes were also detected in electrophoretically separated tegument fractions of virions and light particles and yielded tryptic peptides of masses characteristic of the predicted UL17 protein. We therefore conclude that the UL17 gene products are associated with the virion tegument and note that they are the first tegument-associated proteins shown to be required for cleavage and packaging of viral DNA.


1998 ◽  
Vol 72 (9) ◽  
pp. 7563-7568 ◽  
Author(s):  
Prashant Desai ◽  
Stanley Person

ABSTRACT The herpes simplex virus type 1 (HSV-1) UL35 open reading frame (ORF) encodes a 12-kDa capsid protein designated VP26. VP26 is located on the outer surface of the capsid specifically on the tips of the hexons that constitute the capsid shell. The bioluminescent jellyfish (Aequorea victoria) green fluorescent protein (GFP) was fused in frame with the UL35 ORF to generate a VP26-GFP fusion protein. This fusion protein was fluorescent and localized to distinct regions within the nuclei of transfected cells following infection with wild-type virus. The VP26-GFP marker was introduced into the HSV-1 (KOS) genome resulting in recombinant plaques that were fluorescent. A virus, designated K26GFP, was isolated and purified and was shown to grow as well as the wild-type virus in cell culture. An analysis of the intranuclear capsids formed in K26GFP-infected cells revealed that the fusion protein was incorporated into A, B, and C capsids. Furthermore, the fusion protein incorporated into the virion particle was fluorescent as judged by fluorescence-activated cell sorter (FACS) analysis of infected cells in the absence of de novo protein synthesis. Cells infected with K26GFP exhibited a punctate nuclear fluorescence at early times in the replication cycle. At later times during infection a generalized cytoplasmic and nuclear fluorescence, including fluorescence at the cell membranes, was observed, confirming visually that the fusion protein was incorporated into intranuclear capsids and mature virions.


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