scholarly journals Antiviral Activity of the G-Quadruplex Ligand TMPyP4 against Herpes Simplex Virus-1

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 196
Author(s):  
Sara Artusi ◽  
Emanuela Ruggiero ◽  
Matteo Nadai ◽  
Beatrice Tosoni ◽  
Rosalba Perrone ◽  
...  

The herpes simplex virus 1 (HSV-1) genome is extremely rich in guanine tracts that fold into G-quadruplexes (G4s), nucleic acid secondary structures implicated in key biological functions. Viral G4s were visualized in HSV-1 infected cells, with massive virus cycle-dependent G4-formation peaking during viral DNA replication. Small molecules that specifically interact with G4s have been shown to inhibit HSV-1 DNA replication. We here investigated the antiviral activity of TMPyP4, a porphyrin known to interact with G4s. The analogue TMPyP2, with lower G4 affinity, was used as control. We showed by biophysical analysis that TMPyP4 interacts with HSV-1 G4s, and inhibits polymerase progression in vitro; in infected cells, it displayed good antiviral activity which, however, was independent of inhibition of virus DNA replication or entry. At low TMPyP4 concentration, the virus released by the cells was almost null, while inside the cell virus amounts were at control levels. TEM analysis showed that virus particles were trapped inside cytoplasmatic vesicles, which could not be ascribed to autophagy, as proven by RT-qPCR, western blot, and immunofluorescence analysis. Our data indicate a unique mechanism of action of TMPyP4 against HSV-1, and suggest the unprecedented involvement of currently unknown G4s in viral or antiviral cellular defense pathways.

2020 ◽  
Author(s):  
Enrico R. Barrozo ◽  
Sanae Nakayama ◽  
Pankaj Singh ◽  
Donna M. Neumann ◽  
David C. Bloom

The regulatory functions of 10 individual viral miRNAs that are abundantly expressed from the Herpes Simplex Virus 1 (HSV-1) latency-associated transcript (LAT) region remain largely unknown. Here, we focus on HSV-1 miRNA miR-H8, which is within the LAT 3p exon, antisense to the first intron of ICP0, and has previously been shown to target a host GPI-anchoring pathway. However, the functions of this miRNA have not been assessed in the context of the viral genome during infection. Therefore, we constructed a recombinant virus lacking miR-H8 (17dmiR-H8) and compared it to the parental wild-type and rescue viruses to characterize phenotypic differences. In rabbit skin cells, 17dmiR-H8 exhibited only subtle reductions in viral yields. In contrast, we found significant decreases in both viral yields (8-fold) and DNA replication (9.9-fold) in murine neuroblastoma cells, while 17dmiR-H8 exhibited a 3.6 fold increase in DNA replication in differentiated human neuronal cells (LUHMES). These cell culture phenotypes suggested potential host and/or neuronal-specific roles for miR-H8 in acute viral replication. To assess whether miR-H8 plays a role in HSV latency or reactivation, we used a human in vitro reactivation model, as well as mouse and rabbit reactivation models. In the LUHMES-induced reactivation model, there was no difference in viral yields at 48 h post-reactivation. In the murine dorsal root ganglia explant and rabbit ocular adrenergic reactivation models, the deletion of miR-H8 had no detectable effect on genome load during latency, or reactivation. These results indicate that miR-H8 is dispensable for establishment of HSV-1 latency and reactivation. IMPORTANCE Herpesviruses have a remarkable ability to sustain lifelong infections by evading host immune responses, establishing a latent reservoir, and by maintaining the ability to reactivate the lytic cascade to transmit the virus to the next host. The HSV-1 latency-associated transcript region is known to regulate many aspects of HSV-1 latency and reactivation, though the mechanisms for these functions remain unknown. To this end, we characterize an HSV-1 recombinant containing a deletion of a LAT-encoded miRNA, miR-H8, and demonstrate that it plays no detectable role in the establishment of latency or reactivation in differentiated human neurons (LUHMES), mouse and rabbit models. Therefore, this study allows us to exclude miR-H8 from phenotypes previously attributed to the LAT region. Elucidating the genetic elements of HSV-1 responsible for the establishment, maintenance, and reactivation from latency may lead to novel strategies for combating persistent herpesvirus infections.


2008 ◽  
Vol 82 (13) ◽  
pp. 6172-6189 ◽  
Author(s):  
Akihisa Kato ◽  
Michiko Tanaka ◽  
Mayuko Yamamoto ◽  
Risa Asai ◽  
Tetsutaro Sata ◽  
...  

ABSTRACT Us3 is a serine/threonine protein kinase encoded by herpes simplex virus 1 (HSV-1). Here, we report the identification of a physiological Us3 phosphorylation site on serine at position 147 (Ser-147) which regulates its protein kinase activity in vitro. Moreover, mutation of this site influences Us3 function, including correct localization of the enzyme and induction of the usual morphological changes in HSV-1-infected cells. These conclusions are based on the following observations: (i) in in vitro kinase assays, a domain of Us3 containing Ser-147 was specifically phosphorylated by Us3 and protein kinase A, while a mutant domain in which Ser-147 was replaced with alanine was not; (ii) in vitro, alanine replacement of Ser-147 (S147A) in Us3 resulted in significant impairment of the kinase activity of the purified molecule expressed in a baculovirus system; (iii) phosphorylation of Ser-147 in Us3 tagged with the monomeric fluorescent protein (FP) VenusA206K (VenusA206K-Us3) from Vero cells infected with a recombinant HSV-1 encoding VenusA206K-Us3 was specifically detected using an antibody that recognizes phosphorylated serine or threonine residues with arginine at the −3 and −2 positions; and (iv) the S147A mutation influenced some but not all Us3 functions, including the ability of the protein to localize itself properly and to induce wild-type cytopathic effects in infected cells. Our results suggest that some of the regulatory activities of Us3 in infected cells are controlled by phosphorylation at Ser-147.


Author(s):  
Z. Hong Zhou ◽  
Jing He ◽  
Joanita Jakana ◽  
J. D. Tatman ◽  
Frazer J. Rixon ◽  
...  

Herpes simplex virus-1 (HSV-1) is a ubiquitous virus which is implicated in diseases ranging from self-curing cold sores to life-threatening infections. The 2500 Å diameter herpes virion is composed of a glycoprotein spike containing, lipid envelope, enclosing a protein layer (the tegument) in which is embedded the capsid (which contains the dsDNA genome). The B-, and A- and C-capsids, representing different morphogenetic stages in HSV-1 infected cells, are composed of 7, and 5 structural proteins respectively. The three capsid types are organized in similar T=16 icosahedral shells with 12 pentons, 150 hexons, and 320 connecting triplexes. Our previous 3D structure study at 26 Å revealed domain features of all these structural components and suggested probable locations for the outer shell proteins, VP5, VP26, VP19c and VP23. VP5 makes up most of both pentons and hexons. VP26 appeared to bind to the VP5 subunit in hexon but not to that in penton.


2017 ◽  
Vol 91 (12) ◽  
Author(s):  
Fumio Maeda ◽  
Jun Arii ◽  
Yoshitaka Hirohata ◽  
Yuhei Maruzuru ◽  
Naoto Koyanagi ◽  
...  

ABSTRACT Upon herpes simplex virus 1 (HSV-1) infection, the CD98 heavy chain (CD98hc) is redistributed around the nuclear membrane (NM), where it promotes viral de-envelopment during the nuclear egress of nucleocapsids. In this study, we attempted to identify the factor(s) involved in CD98hc accumulation and demonstrated the following: (i) the null mutation of HSV-1 UL34 caused specific dispersion throughout the cytoplasm of CD98hc and the HSV-1 de-envelopment regulators, glycoproteins B and H (gB and gH); (ii) as observed with CD98hc, gB, and gH, wild-type HSV-1 infection caused redistribution of the endoplasmic reticulum (ER) markers calnexin and ERp57 around the NM, whereas the UL34-null mutation caused cytoplasmic dispersion of these markers; (iii) the ER markers colocalized efficiently with CD98hc, gB, and gH in the presence and absence of UL34 in HSV-1-infected cells; (iv) at the ultrastructural level, wild-type HSV-1 infection caused ER compression around the NM, whereas the UL34-null mutation caused cytoplasmic dispersion of the ER; and (v) the UL34-null mutation significantly decreased the colocalization efficiency of lamin protein markers of the NM with CD98hc and gB. Collectively, these results indicate that HSV-1 infection causes redistribution of the ER around the NM, with resulting accumulation of ER-associated CD98hc, gB, and gH around the NM and that UL34 is required for ER redistribution, as well as for efficient recruitment to the NM of the ER-associated de-envelopment factors. Our study suggests that HSV-1 induces remodeling of the global ER architecture for recruitment of regulators mediating viral nuclear egress to the NM. IMPORTANCE The ER is an important cellular organelle that exists as a complex network extending throughout the cytoplasm. Although viruses often remodel the ER to facilitate viral replication, information on the effects of herpesvirus infections on ER morphological integrity is limited. Here, we showed that HSV-1 infection led to compression of the global ER architecture around the NM, resulting in accumulation of ER-associated regulators associated with nuclear egress of HSV-1 nucleocapsids. We also identified HSV-1 UL34 as a viral factor that mediated ER remodeling. Furthermore, we demonstrated that UL34 was required for efficient targeting of these regulators to the NM. To our knowledge, this is the first report showing that a herpesvirus remodels ER global architecture. Our study also provides insight into the mechanism by which the regulators for HSV-1 nuclear egress are recruited to the NM, where this viral event occurs.


2012 ◽  
Vol 86 (16) ◽  
pp. 8592-8601 ◽  
Author(s):  
Charlotte Mahiet ◽  
Ayla Ergani ◽  
Nicolas Huot ◽  
Nicolas Alende ◽  
Ahmed Azough ◽  
...  

Herpes simplex virus 1 (HSV-1) is a human pathogen that leads to recurrent facial-oral lesions. Its 152-kb genome is organized in two covalently linked segments, each composed of a unique sequence flanked by inverted repeats. Replication of the HSV-1 genome produces concatemeric molecules in which homologous recombination events occur between the inverted repeats. This mechanism leads to four genome isomers (termed P, IS, IL, and ILS) that differ in the relative orientations of their unique fragments. Molecular combing analysis was performed on DNA extracted from viral particles and BSR, Vero, COS-7, and Neuro-2a cells infected with either strain SC16 or KOS of HSV-1, as well as from tissues of experimentally infected mice. Using fluorescence hybridization, isomers were repeatedly detected and distinguished and were accompanied by a large proportion of noncanonical forms (40%). In both cell and viral-particle extracts, the distributions of the four isomers were statistically equivalent, except for strain KOS grown in Vero and Neuro-2a cells, in which P and IS isomers were significantly overrepresented. In infected cell extracts, concatemeric molecules as long as 10 genome equivalents were detected, among which, strikingly, the isomer distributions were equivalent, suggesting that any such imbalance may occur during encapsidation.In vivo, for strain KOS-infected trigeminal ganglia, an unbalanced distribution distinct from the onein vitrowas observed, along with a considerable proportion of noncanonical assortment.


2008 ◽  
Vol 82 (11) ◽  
pp. 5198-5211 ◽  
Author(s):  
Ken Sugimoto ◽  
Masashi Uema ◽  
Hiroshi Sagara ◽  
Michiko Tanaka ◽  
Tetsutaro Sata ◽  
...  

ABSTRACT We report here the construction of a triply fluorescent-tagged herpes simplex virus 1 (HSV-1) expressing capsid protein VP26, tegument protein VP22, and envelope protein gB as fusion proteins with monomeric yellow, red, and cyan fluorescent proteins, respectively. The recombinant virus enabled us to monitor the dynamics of these capsid, tegument, and envelope proteins simultaneously in the same live HSV-1-infected cells and to visualize single extracellular virions with three different fluorescent emissions. In Vero cells infected by the triply fluorescent virus, multiple cytoplasmic compartments were found to be induced close to the basal surfaces of the infected cells (the adhesion surfaces of the infected cells on the solid growth substrate). Major capsid, tegument, and envelope proteins accumulated and colocalized in the compartments, as did marker proteins for the trans-Golgi network (TGN) which has been implicated to be the site of HSV-1 secondary envelopment. Moreover, formation of the compartments was correlated with the dynamic redistribution of the TGN proteins induced by HSV-1 infection. These results suggest that HSV-1 infection causes redistribution of TGN membranes to form multiple cytoplasmic compartments, possibly for optimal secondary envelopment. This is the first real evidence for the assembly of all three types of herpesvirus proteins—capsid, tegument, and envelope membrane proteins—in TGN.


2007 ◽  
Vol 102 (4) ◽  
pp. 469-472 ◽  
Author(s):  
Márcia Cristina Carriel-Gomes ◽  
Jadel Müller Kratz ◽  
Margherita Anna Barracco ◽  
Evelyne Bachére ◽  
Célia Regina Monte Barardi ◽  
...  

2017 ◽  
Vol 91 (12) ◽  
Author(s):  
Thibaut Deschamps ◽  
Christos Dogrammatzis ◽  
Ranajoy Mullick ◽  
Maria Kalamvoki

ABSTRACT The Cbl E3 ligase has been linked to the down-modulation of surface signaling responses by inducing internalization of surface receptors. The adaptor protein CIN85 is a partner of Cbl that augments many of these interactions. Previously, an interaction was demonstrated between ICP0 and CIN85, which results in the removal of epidermal growth factor receptor (EGFR) from the surface of the infected cells with a concomitant attenuation of EGFR signaling. Here, we examined whether Cbl mediates the removal of the herpes simplex virus 1 (HSV-1) entry receptor Nectin-1 from the surface of infected cells. We found the following: (i) that Cbl, Nectin-1, and the viral glycoprotein D (gD) form a complex in infected cells; (ii) that during infection Nectin-1 is removed from the surface of the infected cells but is retained on the surface of cells that have been depleted of Cbl; and (iii) that in cells infected with a ΔICP0 mutant virus, Nectin-1 remained on the cell surface. Thus, Cbl is necessary but not sufficient for the removal of Nectin-1 from the cell surface. In addition, we observed that in Cbl-depleted cells there was enhanced entry after infection. These cells were susceptible to secondary infections by HSV-1. Viral entry in CIN85-depleted cells was only moderately enhanced compared to that in the Cbl-depleted cells, suggesting that the Cbl–Nectin-1 interaction is likely the key to the downregulation of surface Nectin-1. The removal of the HSV-1 entry receptor Nectin-1 from the surface of the infected cells may be part of the strategy of the virus to efficiently spread to uninfected cells. IMPORTANCE The Cbl E3 ligase suppresses surface signaling responses by inducing internalization of surface components. The targets of Cbl include such components as immune system receptors, growth factor receptors, adhesion, and cell-to-cell contact molecules. The immediate early protein ICP0 of herpes simplex virus 1 (HSV-1) interacts with CIN85, an adaptor protein that augments Cbl functions. The consequence of this interaction is the removal of the epidermal growth factor receptor (EGFR) from the surface of the infected cells with concomitant suppression of the EGF ligand signaling. The viral entry receptor Nectin-1 is also internalized during HSV-1 infection in a Cbl-dependent mechanism, and that increases the opportunity of the virus to spread to uninfected cells. The diversion of the Cbl/CIN85 endocytic machinery may be a strategy utilized by the virus to alter the cell surface pattern to prevent detrimental host responses.


2020 ◽  
Vol 94 (16) ◽  
Author(s):  
Kati Tormanen ◽  
Shaohui Wang ◽  
Ujjaldeep Jaggi ◽  
Homayon Ghiasi

ABSTRACT The immune modulatory protein herpes virus entry mediator (HVEM) is one of several cellular receptors used by herpes simplex virus 1 (HSV-1) for cell entry. HVEM binds to HSV-1 glycoprotein D (gD) but is not necessary for HSV-1 replication in vitro or in vivo. Previously, we showed that although HSV-1 replication was similar in wild-type (WT) control and HVEM−/− mice, HSV-1 does not establish latency or reactivate effectively in mice lacking HVEM, suggesting that HVEM is important for these functions. It is not known whether HVEM immunomodulatory functions contribute to latency and reactivation or whether its binding to gD is necessary. We used HVEM−/− mice to establish three transgenic mouse lines that express either human WT HVEM or human or mouse HVEM with a point mutation that ablates its ability to bind to gD. Here, we show that HVEM immune function, not its ability to bind gD, is required for WT levels of latency and reactivation. We further show that HVEM binding to gD does not affect expression of the HVEM ligands BTLA, CD160, or LIGHT. Interestingly, our results suggest that binding of HVEM to gD may contribute to efficient upregulation of CD8α but not PD1, TIM-3, CTLA4, or interleukin 2 (IL-2). Together, our results establish that HVEM immune function, not binding to gD, mediates establishment of latency and reactivation. IMPORTANCE HSV-1 is a common cause of ocular infections worldwide and a significant cause of preventable blindness. Corneal scarring and blindness are consequences of the immune response induced by repeated reactivation events. Therefore, HSV-1 therapeutic approaches should focus on preventing latency and reactivation. Our data suggest that the immune function of HVEM plays an important role in the HSV-1 latency and reactivation cycle that is independent of HVEM binding to gD.


2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Elena Criscuolo ◽  
Matteo Castelli ◽  
Roberta A. Diotti ◽  
Virginia Amato ◽  
Roberto Burioni ◽  
...  

ABSTRACTHerpes simplex virus 1 (HSV-1) and HSV-2 can evade serum antibody-mediated neutralization through cell-to-cell transmission mechanisms, which represent one of the central steps in disease reactivation. To address the role of humoral immunity in controlling HSV-1 and HSV-2 replication, we analyzed serum samples from 44 HSV-1 and HSV-2 seropositive subjects by evaluating (i) their efficiency in binding both the purified viral particles and recombinant gD and gB viral glycoproteins, (ii) their neutralizing activity, and (iii) their capacity to inhibit the cell-to-cell virus passagein vitro. All of the sera were capable of binding gD, gB, and whole virions, and all sera significantly neutralized cell-free virus. However, neither whole sera nor purified serum IgG fraction was able to inhibit significantly cell-to-cell virus spreading inin vitropost-virus-entry infectious assays. Conversely, when spiked with an already described anti-gD human monoclonal neutralizing antibody capable of inhibiting HSV-1 and -2 cell-to-cell transmission, each serum boosted both its neutralizing and post-virus-entry inhibitory activity, with no interference exerted by serum antibody subpopulations.IMPORTANCEDespite its importance in the physiopathology of HSV-1 and -2 infections, the cell-to-cell spreading mechanism is still poorly understood. The data shown here suggest that infection-elicited neutralizing antibodies capable of inhibiting cell-to-cell virus spread can be underrepresented in most infected subjects. These observations can be of great help in better understanding the role of humoral immunity in controlling virus reactivation and in the perspective of developing novel therapeutic strategies, studying novel correlates of protection, and designing effective vaccines.


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