scholarly journals Entry Mechanisms of Herpes Simplex Virus 1 into Murine Epidermis: Involvement of Nectin-1 and Herpesvirus Entry Mediator as Cellular Receptors

2014 ◽  
Vol 89 (1) ◽  
pp. 262-274 ◽  
Author(s):  
Philipp Petermann ◽  
Katharina Thier ◽  
Elena Rahn ◽  
Frazer J. Rixon ◽  
Wilhelm Bloch ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Ex Vivo ◽  
Target Tissue ◽  
Herpes Simplex Virus 1 ◽  
Simplex Virus ◽  
The Impact ◽  
Herpesvirus Entry Mediator ◽  
Hsv 1

ABSTRACTSkin keratinocytes represent a primary entry site for herpes simplex virus 1 (HSV-1)in vivo. The cellular proteins nectin-1 and herpesvirus entry mediator (HVEM) act as efficient receptors for both serotypes of HSV and are sufficient for disease development mediated by HSV-2 in mice. How HSV-1 enters skin and whether both nectin-1 and HVEM are involved are not known. We addressed the impact of nectin-1 during entry of HSV-1 into murine epidermis and investigated the putative contribution of HVEM. Usingex vivoinfection of murine epidermis, we showed that HSV-1 entered the basal keratinocytes of the epidermis very efficiently. In nectin-1-deficient epidermis, entry was strongly reduced. Almost no entry was observed, however, in nectin-1-deficient keratinocytes grown in culture. This observation correlated with the presence of HVEM on the keratinocyte surface in epidermis and with the lack of HVEM expression in nectin-1-deficient primary keratinocytes. Our results suggest that nectin-1 is the primary receptor in epidermis, while HVEM has a more limited role. For primary murine keratinocytes, on which nectin-1 acts as a single receptor, electron microscopy suggested that HSV-1 can enter both by direct fusion with the plasma membrane and via endocytic vesicles. Thus, we concluded that nectin-1 directs internalization into keratinocytes via alternative pathways. In summary, HSV-1 entry into epidermis was shown to strongly depend on the presence of nectin-1, but the restricted presence of HVEM can potentially replace nectin-1 as a receptor, illustrating the flexibility employed by HSV-1 to efficiently invade tissuein vivo.IMPORTANCEHerpes simplex virus (HSV) can cause a range of diseases in humans, from uncomplicated mucocutaneous lesions to life-threatening infections. The skin is one target tissue of HSV, and the question of how the virus overcomes the protective skin barrier and penetrates into the tissue to reach its receptors is still open. Previous studies analyzing entry into cells grownin vitrorevealed nectin-1 and HVEM as HSV receptors. To explore the contributions of nectin-1 and HVEM to entry into a natural target tissue, we established anex vivoinfection model. Using nectin-1- or HVEM-deficient mice, we demonstrated the distinct involvement of nectin-1 and HVEM for HSV-1 entry into epidermis and characterized the internalization pathways. Such advances in understanding the involvement of receptors in tissue are essential preconditions for unraveling HSV invasion of skin, which in turn will allow the development of antiviral reagents.

Susceptibility of human and murine dermal fibroblasts to Herpes simplex Virus 1 in the absence and presence of extracellular matrix

2021 ◽  
Author(s):  
Lisa Wirtz ◽  
Nydia C. De La Cruz ◽  
Maureen Möckel ◽  
Dagmar Knebel-Mörsdorf
Keyword(s):  
Extracellular Matrix ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Ex Vivo ◽  
Dermal Fibroblasts ◽  
Herpes Simplex Virus 1 ◽  
Human Dermis ◽  
Simplex Virus ◽  
Hsv 1

Herpes simplex virus 1 (HSV-1) invades its human host via the skin and mucosa and initiates infection in the epithelium. While human and murine epidermis are highly susceptible to HSV-1, we recently observed rare infected cells in the human dermis and only minor infection efficiency in murine dermis upon ex vivo infection. Here, we investigated why cells in the dermis are so inefficiently infected and explored potential differences between murine and human dermal fibroblasts. In principle, primary fibroblasts are highly susceptible to HSV-1, however, we found a delayed infection onset in human compared to murine cells. Intriguingly, only a minor delayed onset of infection was evident in collagen-embedded compared to unembedded human fibroblasts although expression of the receptor nectin-1 dropped after collagen-embedding. This finding is in contrast to previous observations with murine fibroblasts where collagen-embedding delayed infection. The application of latex beads revealed limited penetration in the dermis which was more pronounced in human compared to murine dermis supporting the species-specific differences already observed for HSV-1 invasion. Our results suggest that the distinct organization of human and murine dermis contribute to the presence and accessibility of the HSV-1 receptors as well as to the variable barrier function of the extracellular matrix. These contributions, in turn, give rise to the inefficient viral access to cells in the dermis while dermal fibroblasts in culture are well infected. Importance Dermal fibroblasts are exposed to HSV-1 upon invasion in skin during in vivo infection. Thus, fibroblasts represent a widely used experimental tool to understand virus-host cell interactions and are highly susceptible in culture. The spectrum of fibroblasts’ characteristics in their in vivo environment, however, clearly differs from the observations under cell culture conditions implying putative variations in virus-cell interactions. This becomes evident when ex vivo infection studies in murine as well as human dermis revealed the rather inefficient penetration of HSV-1 in the tissue and uptake in the dermal fibroblasts. Here, we initiated studies to explore the contributions of receptor presence and accessibility to efficient infection of dermal fibroblasts. Our results strengthen the heterogeneity of murine and human dermis and imply that the interplay between dermal barrier function and receptor presence determine how well HSV-1 penetrates the dermis.

scholarly journals Mechanical Barriers Restrict Invasion of Herpes Simplex Virus 1 into Human Oral Mucosa

2017 ◽  
Vol 91 (22) ◽  
Author(s):  
Katharina Thier ◽  
Philipp Petermann ◽  
Elena Rahn ◽  
Daniel Rothamel ◽  
Wilhelm Bloch ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Oral Mucosa ◽  
Viral Entry ◽  
Ex Vivo ◽  
Target Tissue ◽  
Herpes Simplex Virus 1 ◽  
Epithelial Barriers ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Oral mucosa is one of the main target tissues of the human pathogen herpes simplex virus 1 (HSV-1). How the virus overcomes the protective epithelial barriers and penetrates the tissue to reach its receptors and initiate infection is still unclear. Here, we established an ex vivo infection assay with human oral mucosa that allows viral entry studies in a natural target tissue. The focus was on the susceptibility of keratinocytes in the epithelium and the characterization of cellular receptors that mediate viral entry. Upon ex vivo infection of gingiva or vestibular mucosa, we observed that intact human mucosa samples were protected from viral invasion. In contrast, the basal layer of the oral epithelium was efficiently invaded once the connective tissue and the basement membrane were removed. Later during infection, HSV-1 spread from basal keratinocytes to upper layers, demonstrating the susceptibility of the stratified squamous epithelium to HSV-1. The analysis of potential receptors revealed nectin-1 on most mucosal keratinocytes, whereas herpesvirus entry mediator (HVEM) was found only on a subpopulation of cells, suggesting that nectin-1 acts as primary receptor for HSV-1 in human oral mucosa. To mimic the supposed entry route of HSV-1 via microlesions in vivo, we mechanically wounded the mucosa prior to infection. While we observed a limited number of infected keratinocytes in some wounded mucosa samples, other samples showed no infected cells. Thus, we conclude that mechanical wounding of mucosa is insufficient for the virus to efficiently overcome epithelial barriers and to make entry-mediating receptors accessible. IMPORTANCE To invade the target tissue of its human host during primary infection, herpes simplex virus (HSV) must overcome the epithelial barriers of mucosa, skin, or cornea. For most viruses, the mechanisms underlying the invasion into the target tissues of their host organism are still open. Here, we established an ex vivo infection model of human oral mucosa to explore how HSV can enter its target tissue. Our results demonstrate that intact mucosa samples and even compromised tissue allow only very limited access of HSV to keratinocytes. Detailed understanding of barrier functions is an essential precondition to unravel how HSV bypasses the barriers and approaches its receptors in tissue and why it is beneficial for the virus to use a cell-cell adhesion molecule, such as nectin-1, as a receptor.

scholarly journals Invasion of Herpes Simplex Virus 1 into Murine Dermis: Role of Nectin-1 and Herpesvirus Entry Mediator as Cellular Receptors during Aging

2019 ◽  
Vol 94 (5) ◽  
Author(s):  
Lisa Wirtz ◽  
Maureen Möckel ◽  
Dagmar Knebel-Mörsdorf
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dermal Fibroblasts ◽  
Target Tissue ◽  
Herpes Simplex Virus 1 ◽  
Infection Efficiency ◽  
Infected Cells ◽  
Simplex Virus ◽  
Herpesvirus Entry Mediator ◽  
Hsv 1

ABSTRACT Skin is a major target tissue of herpes simplex virus 1 (HSV-1), and we are only beginning to understand how individual receptors contribute to the initiation of infection in tissue. We recently demonstrated the impact of the receptors nectin-1 and herpesvirus entry mediator (HVEM) for entry of HSV-1 into murine epidermis. Here, we focus on viral invasion into the dermis, a further critical target tissue in vivo. In principle, murine dermal fibroblasts are highly susceptible to HSV-1, and we previously showed that nectin-1 and HVEM can act as alternative receptors. To characterize their contribution as receptors in dermal tissue, we established an ex vivo infection assay of murine dermis. Only after separation of the epidermis from the dermis, we observed single infected cells in the upper dermis from juvenile mice at 5 h postinfection with increasing numbers of infected cells at later times. While nectin-1-expressing cells were less frequently detected, we found HVEM expressed on most cells of juvenile dermis. The comparison of infection efficiency during aging revealed a strong delay in the onset of infection in the dermis from aged mice. This observation correlated with a decrease in nectin-1-expressing fibroblasts during aging while the number of HVEM-expressing cells remained stable. Accordingly, aged nectin-1-deficient dermis was less susceptible to HSV-1 than the dermis from control mice. Thus, we conclude that the reduced availability of nectin-1 in aged dermis is a key contributor to a decrease in infection efficiency during aging. IMPORTANCE HSV-1 is a prevalent human pathogen which invades skin and mucocutaneous linings. So far, the underlying mechanisms of how the virus invades tissue, reaches its receptors, and initiates infection are still unresolved. To unravel the mechanical prerequisites that limit or favor viral invasion into tissue, we need to understand the contribution of the receptors that are involved in viral internalization. Here, we investigated the invasion process into murine dermis with the focus on receptor availability and found that infection efficiency decreases in aging mice. Based on studies of the expression of the receptors nectin-1 and HVEM, we suggest that the decreasing number of nectin-1-expressing fibroblasts leads to a delayed onset of infection in the dermis from aged compared to juvenile mice. Our results imply that the level of infection efficiency in murine dermis is closely linked to the availability of the receptor nectin-1 and can change during aging.

scholarly journals Role of Nectin-1 and Herpesvirus Entry Mediator as Cellular Receptors for Herpes Simplex Virus 1 on Primary Murine Dermal Fibroblasts

2015 ◽  
Vol 89 (18) ◽  
pp. 9407-9416 ◽  
Author(s):  
Philipp Petermann ◽  
Elena Rahn ◽  
Katharina Thier ◽  
Mei-Ju Hsu ◽  
Frazer J. Rixon ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Ex Vivo ◽  
Dermal Fibroblasts ◽  
Herpes Simplex Virus 1 ◽  
Viral Spread ◽  
Simplex Virus ◽  
Herpesvirus Entry Mediator ◽  
Hsv 1

ABSTRACTThe cellular proteins nectin-1 and herpesvirus entry mediator (HVEM) can both mediate the entry of herpes simplex virus 1 (HSV-1). We have recently shown how these receptors contribute to infection of skin by investigating HSV-1 entry into murine epidermis.Ex vivoinfection studies reveal nectin-1 as the primary receptor in epidermis, whereas HVEM has a more limited role. Although the epidermis represents the outermost layer of skin, the contribution of nectin-1 and HVEM in the underlying dermis is still open. Here, we analyzed the role of each receptor during HSV-1 entry in murine dermal fibroblasts that were deficient in expression of either nectin-1 or HVEM or both receptors. Because infection was not prevented by the absence of either nectin-1 or HVEM, we conclude that they can act as alternative receptors. Although HVEM was found to be highly expressed on fibroblasts, entry was delayed in nectin-1-deficient cells, suggesting that nectin-1 acts as the more efficient receptor. In the absence of both receptors, entry was strongly delayed leading to a much reduced viral spread and virus production. These results suggest an unidentified cellular component that acts as alternate but inefficient receptor for HSV-1 on dermal fibroblasts. Characterization of the cellular entry mechanism suggests that HSV-1 can enter dermal fibroblasts both by direct fusion with the plasma membrane and via endocytic vesicles and that this is not dependent on the presence or absence of nectin-1. Entry was also shown to require dynamin and cholesterol, suggesting comparable entry pathways in keratinocytes and dermal fibroblasts.IMPORTANCEHerpes simplex virus (HSV) is a human pathogen which infects its host via mucosal surfaces or abraded skin. To understand how HSV-1 overcomes the protective barrier of mucosa or skin and reaches its receptors in tissue, it is essential to know which receptors contribute to the entry into individual skin cells. Previously, we have explored the contribution of nectin-1 and herpesvirus entry mediator (HVEM) as receptors for HSV-1 entry into murine epidermis, where keratinocytes form the major cell type. Since the underlying dermis consists primarily of fibroblasts, we have now extended our study of HSV-1 entry to dermal fibroblasts isolated from nectin-1- or HVEM-deficient mice or from mice deficient in both receptors. Our results demonstrate a role for both nectin-1 and HVEM as receptors and suggest a further receptor which appears much less efficient.

scholarly journals Structural Variability of the Herpes Simplex Virus 1 GenomeIn VitroandIn Vivo

2012 ◽  
Vol 86 (16) ◽  
pp. 8592-8601 ◽  
Author(s):  
Charlotte Mahiet ◽  
Ayla Ergani ◽  
Nicolas Huot ◽  
Nicolas Alende ◽  
Ahmed Azough ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Considerable Proportion ◽  
Inverted Repeats ◽  
Herpes Simplex Virus 1 ◽  
Cell Extracts ◽  
Simplex Virus ◽  
Hsv 1

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.

scholarly journals Restoring Herpesvirus Entry Mediator (HVEM) Immune Function in HVEM−/− Mice Rescues Herpes Simplex Virus 1 Latency and Reactivation Independently of Binding to Glycoprotein D

2020 ◽  
Vol 94 (16) ◽  
Author(s):  
Kati Tormanen ◽  
Shaohui Wang ◽  
Ujjaldeep Jaggi ◽  
Homayon Ghiasi
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Immune Function ◽  
Interleukin 2 ◽  
Glycoprotein D ◽  
Herpes Simplex Virus 1 ◽  
Simplex Virus ◽  
Hsv 1

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.

scholarly journals Herpes Simplex Virus 1 Latency and the Kinetics of Reactivation Are Regulated by a Complex Network of Interactions between the Herpesvirus Entry Mediator, Its Ligands (gD, BTLA, LIGHT, and CD160), and the Latency-Associated Transcript

2018 ◽  
Vol 92 (24) ◽  
Author(s):  
Shaohui Wang ◽  
Alexander V. Ljubimov ◽  
Ling Jin ◽  
Klaus Pfeffer ◽  
Mitchell Kronenberg ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Trigeminal Ganglia ◽  
Wild Type ◽  
Herpes Simplex Virus 1 ◽  
Latently Infected ◽  
Simplex Virus ◽  
Kinetics Of ◽  
Herpesvirus Entry Mediator ◽  
Hsv 1

ABSTRACTRecently, we reported that the herpesvirus entry mediator (HVEM; also called TNFRSF14 or CD270) is upregulated by the latency-associated transcript (LAT) of herpes simplex virus 1 (HSV-1) and that the absence of HVEM affects latency reactivation but not primary infection in ocularly infected mice. gD has been shown to bind to HVEM. LIGHT (TNFSF14), CD160, and BTLA (B- and T-lymphocyte attenuator) also interact with HVEM and can interfere with HSV gD binding. It was not known if LIGHT, CD160, or BTLA affected the level of latency reactivation in the trigeminal ganglia (TG) of latently infected mice. To address this issue, we ocularly infected LIGHT−/−, CD160−/−, and BTLA−/−mice with LAT(+) and LAT(−) viruses, using similarly infected wild-type (WT) and HVEM−/−mice as controls. The amount of latency, as determined by the levels of gB DNA in the TG of the LIGHT−/−, CD160−/−, and BTLA−/−mice infected with either LAT(+) or LAT(−) viruses, was lower than that in WT mice infected with LAT(+) virus and was similar in WT mice infected with LAT(−) virus. The levels of LAT RNA in HVEM−/−, LIGHT−/−, CD160−/−, and BTLA−/−mice infected with LAT(+) virus were similar and were lower than the levels of LAT RNA in WT mice. However, LIGHT−/−, CD160−/−, and BTLA−/−mice, independent of the presence of LAT, had levels of reactivation similar to those of WT mice infected with LAT(+) virus. Faster reactivation correlated with the upregulation of HVEM transcript. The LIGHT−/−, CD160−/−, and BTLA−/−mice had higher levels of HVEM expression, and this, along with the absence of BTLA, LIGHT, or CD160, may contribute to faster reactivation, while the absence of each molecule, independent of LAT, may have contributed to lower latency. This study suggests that, in the absence of competition with gD for binding to HVEM, LAT RNA is important for WT levels of latency but not for WT levels of reactivation.IMPORTANCEThe effects of BTLA, LIGHT, and CD160 on latency reactivation are not known. We show here that in BTLA, LIGHT, or CD160 null mice, latency is reduced; however, HVEM expression is upregulated compared to that of WT mice, and this upregulation is associated with higher reactivation that is independent of LAT but dependent on gD expression. Thus, one of the mechanisms by which BTLA, LIGHT, and CD160 null mice enhance reactivation appears to be the increased expression of HVEM in the presence of gD. Thus, our results suggest that blockade of HVEM-LIGHT-BTLA-CD160 contributes to reduced HSV-1 latency and reactivation.

scholarly journals Effects of Phosphorylation of Herpes Simplex Virus 1 Envelope Glycoprotein B by Us3 Kinase In Vivo and In Vitro

2009 ◽  
Vol 84 (1) ◽  
pp. 153-162 ◽  
Author(s):  
Takahiko Imai ◽  
Ken Sagou ◽  
Jun Arii ◽  
Yasushi Kawaguchi
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Viral Replication ◽  
Envelope Glycoprotein ◽  
Critical Role ◽  
Glycoprotein B ◽  
Herpes Simplex Virus 1 ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT We recently reported that the herpes simplex virus 1 (HSV-1) Us3 protein kinase phosphorylates threonine at position 887 (Thr-887) in the cytoplasmic tail of envelope glycoprotein B (gB) (A. Kato, J. Arii, I. Shiratori, H. Akashi, H. Arase, and Y. Kawaguchi, J. Virol. 83:250-261, 2009; T. Wisner, C. C. Wright, A. Kato, Y. Kawaguchi, F. Mou, J. D. Baines, R. J. Roller and D. C. Johnson, J. Virol. 83:3115-3126, 2009). In the studies reported here, we examined the effect(s) of this phosphorylation on viral replication and pathogenesis in vivo and present data showing that replacement of gB Thr-887 by alanine significantly reduced viral replication in the mouse cornea and development of herpes stroma keratitis and periocular skin disease in mice. The same effects have been reported for mice infected with a recombinant HSV-1 carrying a kinase-inactive mutant of Us3. These observations suggested that Us3 phosphorylation of gB Thr-887 played a critical role in viral replication in vivo and in HSV-1 pathogenesis. In addition, we generated a monoclonal antibody that specifically reacted with phosphorylated gB Thr-887 and used this antibody to show that Us3 phosphorylation of gB Thr-887 regulated subcellular localization of gB, particularly on the cell surface of infected cells.

scholarly journals RIG-I-Mediated STING Upregulation Restricts Herpes Simplex Virus 1 Infection

2016 ◽  
Vol 90 (20) ◽  
pp. 9406-9419 ◽  
Author(s):  
Yiliu Liu ◽  
Marie-Line Goulet ◽  
Alexandre Sze ◽  
Samar Bel Hadj ◽  
Sidi Mehdi Belgnaoui ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Immune System ◽  
Herpes Simplex ◽  
Innate Immune System ◽  
Innate Immune ◽  
Herpes Simplex Virus 1 ◽  
Dna And Rna ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACTSTING has emerged in recent years as a key player in orchestrating innate immune responses to cytosolic DNA and RNA derived from pathogens. However, the regulation of STING still remains poorly defined. In the present study, we investigated the mechanism of the regulation of STING expression in relation to the RIG-I pathway. Our data show that signaling through RIG-I induces STING expression at both the transcriptional and protein levels in various cell types. STING induction by the RIG-I agonist 5′triphosphorylated RNA (5′pppRNA) was recognized to be a delayed event resulting from an autocrine/paracrine mechanism. Indeed, cotreatment with tumor necrosis factor alpha and type I/II interferon was found to have a synergistic effect on the regulation of STING expression and could be potently decreased by impairing NF-κB and/or STAT1/2 signaling. STING induction significantly contributed to sustainment of the immune signaling cascade following 5′pppRNA treatment. Physiologically, this cross talk between the RNA- and DNA-sensing pathways allowed 5′pppRNA to efficiently block infection by herpes simplex virus 1 (HSV-1) bothin vitroandin vivoin a STING-dependent fashion. These observations demonstrate that STING induction by RIG-I signaling through the NF-κB and STAT1/2 cascades is essential for RIG-I agonist-mediated HSV-1 restriction.IMPORTANCEThe innate immune system represents the first line of defense against invading pathogens. The dysregulation of this system can result in failure to combat pathogens, inflammation, and autoimmune diseases. Thus, precise regulation at each level of the innate immune system is crucial. Recently, a number of studies have established STING to be a central molecule in the innate immune response to cytosolic DNA and RNA derived from pathogens. Here, we describe the regulation of STING via RIG-I-mediated innate immune sensing. We found that STING is synergistically induced via proinflammatory and antiviral cytokine cascades. In addition, we show thatin vivoprotection against herpes simplex virus 1 (HSV-1) by a RIG-I agonist required STING. Our study provides new insights into the cross talk between DNA and RNA pathogen-sensing systems via the control of STING.

scholarly journals A novel bioluminescent herpes simplex virus 1 for in vivo monitoring of herpes simplex encephalitis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Olus Uyar ◽  
Pier-Luc Plante ◽  
Jocelyne Piret ◽  
Marie-Christine Venable ◽  
Julie Carbonneau ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Cell Culture Supernatant ◽  
Herpes Simplex Virus Encephalitis ◽  
Herpes Simplex Virus 1 ◽  
Simplex Virus ◽  
Hsv 1 ◽  
Viral Titers

AbstractHerpes simplex virus 1 (HSV-1) is responsible for herpes simplex virus encephalitis (HSE), associated with a 70% mortality rate in the absence of treatment. Despite intravenous treatment with acyclovir, mortality remains significant, highlighting the need for new anti-herpetic agents. Herein, we describe a novel neurovirulent recombinant HSV-1 (rHSV-1), expressing the fluorescent tdTomato and Gaussia luciferase (Gluc) enzyme, generated by the Clustered regularly interspaced short palindromic repeats (CRISPR)—CRISPR-associated protein 9 (Cas9) (CRISPR-Cas9) system. The Gluc activity measured in the cell culture supernatant was correlated (P = 0.0001) with infectious particles, allowing in vitro monitoring of viral replication kinetics. A significant correlation was also found between brain viral titers and Gluc activity in plasma (R2 = 0.8510, P < 0.0001) collected from BALB/c mice infected intranasally with rHSV-1. Furthermore, evaluation of valacyclovir (VACV) treatment of HSE could also be performed by analyzing Gluc activity in mouse plasma samples. Finally, it was also possible to study rHSV-1 dissemination and additionally to estimate brain viral titers by in vivo imaging system (IVIS). The new rHSV-1 with reporter proteins is not only as a powerful tool for in vitro and in vivo antiviral screening, but can also be used for studying different aspects of HSE pathogenesis.

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