scholarly journals Regulation of Krüppel-Like Factor 15 Expression by Herpes Simplex Virus Type 1 or Bovine Herpesvirus 1 Productive Infection

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1148
Author(s):  
Fouad S. El-mayet ◽  
Kelly S. Harrison ◽  
Clinton Jones

Expression of Krüppel-like factor 15 (KLF15), a stress-induced transcription factor, is induced during bovine herpesvirus 1 (BoHV-1) reactivation from latency, and KLF15 stimulates BoHV-1 replication. Transient transfection studies revealed that KLF15 and glucocorticoid receptor (GR) cooperatively transactivate the BoHV-1-immediate-early transcription unit 1 (IEtu1), herpes simplex virus type 1 (HSV-1) infected cell protein 0 (ICP0), and ICP4 promoters. The IEtu1 promoter drives expression of bICP0 and bICP4, two key BoHV-1 transcriptional regulatory proteins. Based on these studies, we hypothesized infection is a stressful stimulus that increases KLF15 expression and enhances productive infection. New studies demonstrated that silencing KLF15 impaired HSV-1 productive infection, and KLF15 steady-state protein levels were increased at late stages of productive infection. KLF15 was primarily localized to the nucleus following infection of cultured cells with HSV-1, but not BoHV-1. When cells were transfected with a KLF15 promoter construct and then infected with HSV-1, promoter activity was significantly increased. The ICP0 gene, and to a lesser extent, bICP0 transactivated the KLF15 promoter in the absence of other viral proteins. In contrast, BoHV-1 or HSV-1 encoded VP16 had no effect on KLF15 promoter activity. Collectively, these studies revealed that HSV-1 and BoHV-1 productive infection increased KLF15 steady-state protein levels, which correlated with increased virus production.

Author(s):  
Fouad S. El-Mayet ◽  
Kelly S. Harrison ◽  
Clinton Jones

Expression of Krüppel–like factor 15 (KLF15), a stress induced transcription factor, is induced during bovine herpesvirus 1 (BoHV-1) reactivation from latency, and KLF15 stimulates BoHV-1 replication. Transient transfection studies revealed KLF15 and glucocorticoid receptor (GR) cooperatively transactivate the BoHV-1 immediate early transcription unit 1 (IEtu1), herpes sim-plex virus type 1 (HSV-1) infected cell protein 0 (ICP0), and ICP4 promoter. The IEtu1 promoter drives expression of bICP0 and bICP4, two key BoHV-1 transcriptional regulatory proteins. Based on these studies, we hypothesized infection is a stressful stimulus that increases KLF15 ex-pression and enhances productive infection. New studies demonstrated that silencing KLF15 impaired HSV-1 productive infection and KLF15 steady state protein levels were increased at late stages of productive infection. KLF15 was primarily localized to the nucleus following in-fection of cultured cells with HSV-1, but not BoHV-1. When cells were transfected with a KLF15 promoter construct and then infected with HSV-1, promoter activity was significantly increased. The ICP0 gene and to a lesser extent bICP0 transactivated the KLF15 promoter in the absence of other viral proteins. In contrast, BoHV-1 or HSV-1 encoded VP16 had no effect on KLF15 pro-moter activity. Collectively, these studies revealed HSV-1 and BoHV-1 productive infection in-creased KLF15 steady state protein levels, which correlated with increased virus production.


2003 ◽  
Vol 16 (1) ◽  
pp. 79-95 ◽  
Author(s):  
Clinton Jones

SUMMARY Primary infection by herpes simplex virus type 1 (HSV-1) can cause clinical symptoms in the peripheral and central nervous system, upper respiratory tract, and gastrointestinal tract. Recurrent ocular shedding leads to corneal scarring that can progress to vision loss. Consequently, HSV-1 is the leading cause of corneal blindness due to an infectious agent. Bovine herpesvirus 1 (BHV-1) has similar biological properties to HSV-1 and is a significant health concern to the cattle industry. Latency of BHV-1 and HSV-1 is established in sensory neurons of trigeminal ganglia, but latency can be interrupted periodically, leading to reactivation from latency and spread of infectious virus. The ability of HSV-1 and BHV-1 to reactivate from latency leads to virus transmission and can lead to recurrent disease in individuals latently infected with HSV-1. During latency, the only abundant HSV-1 RNA expressed is the latency-associated transcript (LAT). In latently infected cattle, the latency-related (LR) RNA is the only abundant transcript that is expressed. LAT and LR RNA are antisense to ICP0 or bICP0, viral genes that are crucial for productive infection, suggesting that LAT and LR RNA interfere with productive infection by inhibiting ICP0 or bICP0 expression. Numerous studies have concluded that LAT expression is important for the latency-reactivation cycle in animal models. The LR gene has recently been demonstrated to be required for the latency-reactivation cycle in cattle. Several recent studies have demonstrated that LAT and the LR gene inhibit apoptosis (programmed cell death) in trigeminal ganglia of infected animals and transiently transfected cells. The antiapoptotic properties of LAT map to the same sequences that are necessary for promoting reactivation from latency. This review summarizes our current knowledge of factors regulating the latency-reactivation cycle of HSV-1 and BHV-1.


2006 ◽  
Vol 80 (2) ◽  
pp. 1059-1063 ◽  
Author(s):  
Janneke Verhagen ◽  
Ian Hutchinson ◽  
Gillian Elliott

ABSTRACT Previous studies with transfected cells have shown that the herpes simplex virus type 1 (HSV-1) and bovine herpesvirus 1 (BHV-1) UL47 proteins shuttle between the nucleus and the cytoplasm. HSV-1 UL47 has also been shown to bind RNA. Here we examine the BHV-1 UL47 protein in infected cells using a green fluorescent protein-UL47-expressing virus. We show that UL47 is detected in the nucleus early in infection. We use fluorescence loss in photobleaching to show that nuclear UL47 undergoes rapid nucleocytoplasmic shuttling. Furthermore, we demonstrate that actinomycin D inhibits the reaccumulation of UL47 in the nuclei of infected cells. These results suggest that UL47 exhibits behavior similar to that of previously characterized RNA-transporting proteins.


2009 ◽  
Vol 83 (8) ◽  
pp. 3977-3981 ◽  
Author(s):  
Kazima Saira ◽  
You Zhou ◽  
Clinton Jones

ABSTRACT The bICP0 protein encoded by bovine herpesvirus 1 stimulates productive infection and viral gene expression but inhibits interferon (IFN)-dependent transcription. bICP0 inhibits beta IFN (IFN-β) promoter activity and induces degradation of IFN regulatory factor 3 (IRF3). Although bICP0 inhibits the trans-activation activity of IRF7, IRF7 protein levels are not reduced. In this study, we demonstrate that bICP0 is associated with IRF7. Furthermore, bICP0 inhibits the ability of IRF7 to trans-activate the IFN-β promoter in the absence of IRF3 expression. The interaction between bICP0 and IRF7 correlates with reduced trans-activation of the IFN-β promoter by IRF7.


2000 ◽  
Vol 74 (7) ◽  
pp. 3301-3312 ◽  
Author(s):  
Jerome S. Harms ◽  
Xiaodi Ren ◽  
Sergio C. Oliveira ◽  
Gary A. Splitter

ABSTRACT The alphaherpesvirus tegument protein VP22 has been characterized with multiple traits including microtubule reorganization, nuclear localization, and nonclassical intercellular trafficking. However, all these data were derived from studies using herpes simplex virus type 1 (HSV-1) and may not apply to VP22 homologs of other alphaherpesviruses. We compared subcellular attributes of HSV-1 VP22 (HVP22) with bovine herpesvirus 1 (BHV-1) VP22 (BVP22) using green fluorescent protein (GFP)-fused VP22 expression vectors. Fluorescence microscopy of cell lines transfected with these constructs revealed differences as well as similarities between the two VP22 homologs. Compared to that of HVP22, the BVP22 microtubule interaction was much less pronounced. The VP22 nuclear interaction varied, with a marbled or halo appearance for BVP22 and a speckled or nucleolus-bound appearance for HVP22. Both VP22 homologs associated with chromatin at various stages of mitosis and could traffic from expressing cells to the nuclei of nonexpressing cells. However, distinct qualitative differences in microtubule, nuclear, and chromatin association as well as trafficking were observed. The differences in VP22 homolog characteristics revealed in this study will help define VP22 function within HSV-1 and BHV-1 infection.


2001 ◽  
Vol 82 (3) ◽  
pp. 483-492 ◽  
Author(s):  
Melissa Inman ◽  
Yange Zhang ◽  
Vicki Geiser ◽  
Clinton Jones

The bICP0 protein encoded by bovine herpesvirus 1 (BHV-1) is believed to activate transcription and consequently productive infection. Expression of full-length bICP0 protein is toxic in transiently transfected mouse neuroblastoma cells (neuro-2A) in the absence of other viral genes. However, bICP0 does not appear to directly induce apoptosis. Although bICP0 is believed to be functionally similar to the herpes simplex virus type 1-encoded ICP0, the only protein domain that is well conserved is a C3HC4 zinc ring finger located near the N terminus of both proteins. Site-specific mutagenesis of the zinc ring finger of bICP0 demonstrated that it was important for inducing aggregated chromatin structures in transfected cells and toxicity. The zinc ring finger was also required for stimulating productive infection in bovine cells and for trans-activating the thymidine kinase (TK) promoter of herpes simplex virus type 1. Deletion of amino acids spanning 356–677 of bICP0 altered subcellular localization of bICP0 and prevented trans-activation of the TK promoter. However, this deletion did not prevent trans-activation of the viral genome. Taken together, these studies indicated that bICP0 has several functional domains, including the zinc ring finger, which stimulate productive infection and influence cell survival.


2020 ◽  
Vol 94 (21) ◽  
Author(s):  
Jing Zhao ◽  
Liqian Zhu ◽  
Nishani Wijesekera ◽  
Clinton Jones

ABSTRACT Neurotropic Alphaherpesvirinae subfamily members such as bovine herpesvirus 1 (BoHV-1) and herpes simplex virus 1 (HSV-1) establish and maintain lifelong latent infections in neurons. Following infection of ocular, oral, or nasal cavities, sensory neurons within trigeminal ganglia (TG) are an important site for latency. Certain external stressors can trigger reactivation from latency, in part because activation of the glucocorticoid receptor (GR) stimulates productive infection and promoters that drive expression of key viral transcriptional regulators. The Akt serine/threonine protein kinase family is linked to maintaining latency. For example, Akt3 is detected in more TG neurons during BoHV-1 latency than in reactivation and uninfected calves. Furthermore, Akt signaling correlates with maintaining HSV-1 latency in certain neuronal models of latency. Finally, an active Akt protein kinase is crucial for the ability of the HSV-1 latency-associated transcript (LAT) to inhibit apoptosis in neuronal cell lines. Consequently, we hypothesized that viral and/or cellular factors impair stress-induced transcription and reduce the incidence of reactivation triggered by low levels of stress. New studies demonstrate that Akt1 and Akt2, but not Akt3, significantly reduced GR-mediated transactivation of the BoHV-1 immediate early transcription unit 1 (IEtu1) promoter, the HSV-1 infected cell protein 0 (ICP0) promoter, and the mouse mammary tumor virus long terminal repeat (MMTV-LTR). Akt3, but not Akt1 or Akt2, significantly enhanced neurite formation in mouse neuroblastoma cells, which correlates with repairing damaged neurons. These studies suggest that unique biological properties of the three Akt family members promote the maintenance of latency in differentiated neurons. IMPORTANCE External stressful stimuli are known to increase the incidence of reactivation of Alphaherpesvirinae subfamily members. Activation of the glucocorticoid receptor (GR) by the synthetic corticosteroid dexamethasone (DEX) stimulates bovine herpesvirus 1 (BoHV-1) and herpes simplex virus 1 (HSV-1) reactivation. Furthermore, GR and dexamethasone stimulate productive infection and promoters that drive expression of viral transcriptional regulators. These observations lead us to predict that stress-induced transcription is impaired by factors abundantly expressed during latency. Interestingly, activation of the Akt family of serine/threonine protein kinases is linked to maintenance of latency. New studies reveal that Akt1 and Ak2, but not Akt3, impaired GR- and dexamethasone-mediated transactivation of the BoHV-1 immediate early transcription unit 1 and HSV-1 ICP0 promoters. Strikingly, Akt3, but not Akt1 or Akt2, stimulated neurite formation in mouse neuroblastoma cells, a requirement for neurogenesis. These studies provide insight into how Akt family members may promote the maintenance of lifelong latency.


2018 ◽  
Vol 92 (22) ◽  
Author(s):  
Tiffany Russell ◽  
Ben Bleasdale ◽  
Michael Hollinshead ◽  
Gillian Elliott

ABSTRACTDespite differences in the pathogenesis and host range of alphaherpesviruses, many stages of their morphogenesis are thought to be conserved. Here, an ultrastructural study of bovine herpesvirus 1 (BoHV-1) envelopment revealed profiles similar to those previously found for herpes simplex virus 1 (HSV-1), with BoHV-1 capsids associating with endocytic tubules. Consistent with the similarity of their genomes and envelopment strategies, the proteomic compositions of BoHV-1 and HSV-1 virions were also comparable. However, BoHV-1 morphogenesis exhibited a diversity in envelopment events. First, heterogeneous primary envelopment profiles were readily detectable at the inner nuclear membrane of BoHV-1-infected cells. Second, the BoHV-1 progeny comprised not just full virions but also an abundance of capsidless, noninfectious light particles (L-particles) that were released from the infected cells in numbers similar to those of virions and in the absence of DNA replication. Proteomic analysis of BoHV-1 L-particles and the much less abundant HSV-1 L-particles revealed that they contained the same complement of envelope proteins as virions but showed variations in tegument content. In the case of HSV-1, the UL46 tegument protein was reproducibly found to be >6-fold enriched in HSV-1 L-particles. More strikingly, the tegument proteins UL36, UL37, UL21, and UL16 were depleted in BoHV-1 but not HSV-1 L-particles. We propose that these combined differences reflect the presence of truly segregated “inner” and “outer” teguments in BoHV-1, making it a critical system for studying the structure and process of tegumentation and envelopment.IMPORTANCEThe alphaherpesvirus family includes viruses that infect humans and animals. Hence, not only do they have a significant impact on human health, but they also have a substantial economic impact on the farming industry. While the pathogenic manifestations of the individual viruses differ from host to host, their relative genetic compositions suggest similarity at the molecular level. This study provides a side-by-side comparison of the particle outputs from the major human pathogen HSV-1 and the veterinary pathogen BoHV-1. Ultrastructural and proteomic analyses have revealed that both viruses have broadly similar morphogenesis profiles and infectious virus compositions. However, the demonstration that BoHV-1 has the capacity to generate vast numbers of capsidless enveloped particles that differ from those produced by HSV-1 in composition implies a divergence in the cell biology of these viruses that impacts our general understanding of alphaherpesvirus morphogenesis.


2007 ◽  
Vol 81 (7) ◽  
pp. 3077-3086 ◽  
Author(s):  
Kazima Saira ◽  
You Zhou ◽  
Clinton Jones

ABSTRACT The ICP0 protein (bICP0) encoded by bovine herpesvirus 1 is the major viral regulatory protein because it stimulates all viral promoters and, consequently, productive infection. Like other ICP0 analogues encoded by Alphaherpesvirinae subfamily members, bICP0 contains a zinc RING finger near its amino terminus that is necessary for activating transcription, regulating subcellular localization, and inhibiting interferon-dependent transcription. In this study, we discovered that sequences near the C terminus, and the zinc RING finger, are necessary for inhibiting the human beta interferon (IFN-β) promoter. In contrast to herpes simplex virus type 1-encoded ICP0, bICP0 reduces interferon response factor 3 (IRF3), but not IRF7, protein levels in transiently transfected cells. The zinc RING finger and sequences near the C terminus are necessary for bICP0-induced degradation of IRF3. A proteasome inhibitor, lactacystin, interfered with bICP0-induced degradation of IRF3, suggesting that bICP0, directly or indirectly, targets IRF3 for proteasome-dependent degradation. IRF3, but not IRF7, is not readily detectable in the nuclei of productively infected bovine cells during the late stages of infection. In the context of productive infection, IRF3 and IRF7 are detected in the nucleus at early times after infection. At late times after infection, IRF7, but not IRF3, is still detectable in the nuclei of infected cells. Collectively, these studies suggest that the ability of bICP0 to reduce IRF3 protein levels is important with respect to disarming the IFN response during productive infection.


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