Abstract 5395: Mutant oncolytic Herpes simplex virus expressing yeast cytosine deaminase in combination with 5-FC: Viral replication and prodrug bioactivation kinetics in vivo

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.

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A herpes simplex virus type 1 mutant containing a nontransinducing Vmw65 protein establishes latent infection in vivo in the absence of viral replication and reactivates efficiently from explanted trigeminal ganglia.

Journal of Virology ◽

10.1128/jvi.64.4.1630-1638.1990 ◽

1990 ◽

Vol 64 (4) ◽

pp. 1630-1638 ◽

Cited By ~ 91

Author(s):

I Steiner ◽

J G Spivack ◽

S L Deshmane ◽

C I Ace ◽

C M Preston ◽

...

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Viral Replication ◽

Virus Type ◽

Herpes Simplex Virus Type ◽

Latent Infection ◽

Trigeminal Ganglia ◽

Simplex Virus

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Selective Editing of Herpes Simplex Virus 1 Enables Interferon Induction and Viral Replication That Destroy Malignant Cells

Journal of Virology ◽

10.1128/jvi.01761-18 ◽

2018 ◽

Vol 93 (2) ◽

Cited By ~ 1

Author(s):

Xing Liu ◽

Bin He

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Viral Replication ◽

Initiation Factor ◽

Malignant Cells ◽

Herpes Simplex Virus 1 ◽

Tumor Growth And Metastasis ◽

Simplex Virus ◽

Hsv 1

ABSTRACTOncolytic herpes simplex virus 1 (HSV-1), devoid of the γ134.5 gene, exerts antitumor activities. However, the oncolytic effects differ, ranging from pronounced to little responses. Although viral and host factors are involved, much remains to be deciphered. Here we report that engineered HSV-1 ΔN146, bearing amino acids 147 to 263 of γ134.5, replicates competently in and lyses malignant cells refractory to the γ134.5 null mutant. Upon infection, ΔN146 precludes phosphorylation of translation initiation factor eIF2α (α subunit of eukaryotic initiation factor 2), ensuring viral protein synthesis. On the other hand, ΔN146 activates interferon (IFN) regulatory factor 3 (IRF3) and IFN expression, known to prime immunity against virus and tumor. Nevertheless, ΔN146 exhibits sustained replication even exposed to exogenous IFN-α. In a 4T1 tumor model, ΔN146 markedly reduces tumor growth and metastasis formation. This coincides with viral replication or T cell infiltration in primary tumors. ΔN146 is undetectable in normal tissuesin vivo. Targeted HSV-1 editing results in a unique antineoplastic agent that enables inflammation without major interference of viral growth within tumor cells.IMPORTANCEOncolytic herpes simplex virus 1 is a promising agent for cancer immunotherapy. Due to a complex virus-host interaction, less is clear about what viral signature(s) constitutes a potent oncolytic backbone. Through molecular or genetic dissection, we showed that selective editing of the γ134.5 gene enables viral replication in malignant cells, activation of transcription factor IRF3, and subsequent induction of type I IFN. This translates into profoundly reduced primary tumor growth and metastasis burden in an aggressive breast carcinoma modelin vivo. Our work reveals a distinct oncolytic platform that is amendable for further development.

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Expression of RNA interference triggers from an oncolytic herpes simplex virus results in specific silencing in tumour cells in vitro and tumours in vivo

BMC Cancer ◽

10.1186/1471-2407-10-486 ◽

2010 ◽

Vol 10 (1) ◽

Cited By ~ 6

Author(s):

Anna-Maria Anesti ◽

Guy R Simpson ◽

Toby Price ◽

Hardev S Pandha ◽

Robert S Coffin

Keyword(s):

Herpes Simplex Virus ◽

Rna Interference ◽

Herpes Simplex ◽

Tumour Cells ◽

Oncolytic Herpes Simplex Virus ◽

Simplex Virus

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Oncolytic herpes simplex virus infects myeloma cells in vitro and in vivo

Molecular Therapy — Oncolytics ◽

10.1016/j.omto.2021.02.009 ◽

2021 ◽

Vol 20 ◽

pp. 519-531

Author(s):

Jayeeta Ghose ◽

Ada Dona ◽

Mariam Murtadha ◽

Emine Gulsen Gunes ◽

Enrico Caserta ◽

...

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Myeloma Cells ◽

Oncolytic Herpes Simplex Virus ◽

Simplex Virus

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Nectin-1 Expression Correlates with the Susceptibility of Malignant Melanoma to Oncolytic Herpes Simplex Virus In Vitro and In Vivo

Cancers ◽

10.3390/cancers13123058 ◽

2021 ◽

Vol 13 (12) ◽

pp. 3058

Author(s):

Barbara Schwertner ◽

Georg Lindner ◽

Camila Toledo Toledo Stauner ◽

Elisa Klapproth ◽

Clara Magnus ◽

...

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Intralesional Injection ◽

Surface Receptors ◽

Oncolytic Herpes Simplex Virus ◽

Simplex Virus ◽

Oncolytic Activity

Talimogene laherparepvec (T-VEC), an oncolytic herpes simplex virus, is approved for intralesional injection of unresectable stage IIIB/IVM1a melanoma. However, it is still unclear which parameter(s) predict treatment response or failure. Our study aimed at characterizing surface receptors Nectin-1 and the herpes virus entry mediator (HVEM) in addition to intracellular molecules cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING) as potential bio-markers for oncolytic virus treatment. In 20 melanoma cell lines, oncolytic activity of T-VEC was correlated with the expression of Nectin-1 but not HVEM, as evaluated via flow cytometry and immunohistochemistry. Knockout using CRISPR/Cas9 technology confirmed the superior role of Nectin-1 over HVEM for entry and oncolytic activity of T-VEC. Neither cGAS nor STING as evaluated by Western Blot and immunohistochemistry correlated with T-VEC induced oncolysis. The role of these biomarkers was retrospectively analyzed for the response of 35 cutaneous melanoma metastases of 21 patients to intralesional T-VEC injection, with 21 (60.0%) of these lesions responding with complete (n = 16) or partial regression (n = 5). Nectin-1 expression in pretreatment biopsies significantly predicted treatment outcome, while the expression of HVEM, cGAS, and STING was not prognostic. Altogether, Nectin-1 served as biomarker for T-VEC-induced melanoma regression in vitro and in vivo.

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Role of Phosphatidylethanolamine Biosynthesis in Herpes Simplex Virus 1-Infected Cells in Progeny Virus Morphogenesis in the Cytoplasm and in Viral Pathogenicity In Vivo

Journal of Virology ◽

10.1128/jvi.01572-20 ◽

2020 ◽

Vol 94 (24) ◽

Author(s):

Jun Arii ◽

Ayano Fukui ◽

Yuta Shimanaka ◽

Nozomu Kono ◽

Hiroyuki Arai ◽

...

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Viral Replication ◽

Biosynthetic Pathway ◽

Herpes Simplex Virus 1 ◽

Infected Cells ◽

Simplex Virus ◽

Hsv 1

ABSTRACT Glycerophospholipids are major components of cell membranes. Phosphatidylethanolamine (PE) is a glycerophospholipid that is involved in multiple cellular processes, such as membrane fusion, the cell cycle, autophagy, and apoptosis. In this study, we investigated the role of PE biosynthesis in herpes simplex virus 1 (HSV-1) infection by knocking out the host cell gene encoding phosphate cytidylyltransferase 2, ethanolamine (Pcyt2), which is a key rate-limiting enzyme in one of the two major pathways for PE biosynthesis. Pcyt2 knockout reduced HSV-1 replication and caused an accumulation of unenveloped and partially enveloped nucleocapsids in the cytoplasm of an HSV-1-infected cell culture. A similar phenotype was observed when infected cells were treated with meclizine, which is an inhibitor of Pcyt2. In addition, treatment of HSV-1-infected mice with meclizine significantly reduced HSV-1 replication in the mouse brains and improved their survival rates. These results indicated that PE biosynthesis mediated by Pcyt2 was required for efficient HSV-1 envelopment in the cytoplasm of infected cells and for viral replication and pathogenicity in vivo. The results also identified the PE biosynthetic pathway as a possible novel target for antiviral therapy of HSV-associated diseases and raised an interesting possibility for meclizine repositioning for treatment of these diseases, since it is an over-the-counter drug that has been used for decades against nausea and vertigo in motion sickness. IMPORTANCE Glycerophospholipids in cell membranes and virus envelopes often affect viral entry and budding. However, the role of glycerophospholipids in membrane-associated events in viral replication in herpesvirus-infected cells has not been reported to date. In this study, we have presented data showing that cellular PE biosynthesis mediated by Pcyt2 is important for HSV-1 envelopment in the cytoplasm, as well as for viral replication and pathogenicity in vivo. This is the first report showing the importance of PE biosynthesis in herpesvirus infections. Our results showed that inhibition of Pcyt2, a key cell enzyme for PE synthesis, significantly inhibited HSV-1 replication and pathogenicity in mice. This suggested that the PE biosynthetic pathway, as well as the HSV-1 virion maturation pathway, can be a target for the development of novel anti-HSV drugs.

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