Clinical characteristics and outcomes of patients with Herpes Simplex Encephalitis in Vietnam: a retrospective study.

BACKGROUND: Herpes simplex encephalitis (HSE) is an important central nervous infection with severe neurological sequelae. The aim of this study was to describe clinical characteristic and outcomes of patients with HSE in Vietnam. METHODS: This was a retrospective study of 66 patients with herpes simplex encephalitis who admitted to the National Hospital for Tropical Diseases, Hanoi, Vietnam from 2018 to 2021. The detection of herpes simplex virus (HSV) in cerebrospinal fluid was made by the real-time PCR assay. We reported the clinical manifestation on admission and evaluated clinical outcomes at the hospital discharge by modified Rankin Scale (mRS). Multivariate logistic regression analysis was used to analyze the independent risk factors of severe outcomes. RESULTS: Of the 66 patients with laboratory confirmed HSE, the median age was 53 years (IQR 38-60) and 44 patients (69.7%) were male. The most common manifestations included fever (100%), followed by the consciousness disorder (95.5%). Other neurological manifestation were seizures (36.4%), memory disorders (31.8%), language disorders (19.7%) and behavioral disorders (13.6%). Conventional magnetic resonance imaging (MRI) showed 93.8% patients with temporal lobe lesions, followed by abnormalities in insula (50%), frontal lobe (34.4%) and 48.4% of patients had bilateral lesions. At discharge, 19 patients (28.8%) completely recovered, 15 patients (22.7%) had mild sequelae, 28 patients (42.4%) had moderate to severe sequelae. Severe neurological sequelae were memory disorders (55.8%), movement disorders (53.5%), language disorders (30.2%). Multivariate logistic regression analysis showed that Glasgow score decrement at admission, seizures, and time duration from onset of symptoms to the start of Acyclovir treatment > 4 days were independent factors associated with severe outcomes in HSE patients. CONCLUSION: Glasgow score decrement, seizures and delay treatment with Acyclovir were associated with the poor outcome of patients with HSE.

Enhanced IL-12 transgene expression improves oncolytic viroimmunotherapy.

Introduction: Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive sarcomas with unacceptably low cure rates occurring often in patients with neurofibromatosis 1 defects. To investigate oncolytic Herpes Simplex Virus (oHSV) as an immunotherapeutic approach, we compared viral replication, functional activity, and immune response between unarmed and interleukin 12 (IL-12)-armed oncolytic viruses in virus-permissive (B109) and -resistant (67C-4) murine MPNSTs. Methods: This study compared two attenuated IL-12-oHSVs with γ134.5 gene deletions (Δγ134.5) and the same transgene expression cassette. The primary difference in the IL-12-oHSVs was in their ability to counter the translational arrest response in infected cells. Unlike M002 (Δγ134.5, mIL-12), C002 (Δγ134.5, mIL-12, IRS1) expresses an HCMV IRS1 gene and evades dsRNA activated translational arrest in infected cells. Results and discussion: Our results show that oHSV replication and gene expression results in vitro were not predictive of oHSV direct oncolytic activity in vivo. Tumors that supported viral replication in cell culture studies resisted viral replication by both oHSVs and restricted M002 transgene expression in vivo. Furthermore, two IL-12-oHSVs with equivalent transcriptional activity differed in IL-12 protein production in vivo, and the differences in IL-12 protein levels were reflected in immune infiltrate activity changes as well as tumor growth suppression differences between the IL-12-oHSVs. C002-treated tumors exhibited sustained IL-12 production with improved dendritic cells, monocyte-macrophage activity (MHCII, CD80/CD86 upregulation) and a polyfunctional Th1-cell response in the tumor infiltrates. Conclusion: These results suggest that transgene protein production differences between oHSVs in vivo, in addition to replication differences, can impact OV-therapeutic activity.

Cytokine-armed oncolytic herpes simplex viruses: a game-changer in cancer immunotherapy?

Cytokines are small proteins that regulate the growth and functional activity of immune cells, and several have been approved for cancer therapy. Oncolytic viruses are agents that mediate antitumor activity by directly killing tumor cells and inducing immune responses. Talimogene laherparepvec is an oncolytic herpes simplex virus type 1 (oHSV), approved for the treatment of recurrent melanoma, and the virus encodes the human cytokine, granulocyte-macrophage colony-stimulating factor (GM-CSF). A significant advantage of oncolytic viruses is the ability to deliver therapeutic payloads to the tumor site that can help drive antitumor immunity. While cytokines are especially interesting as payloads, the optimal cytokine(s) used in oncolytic viruses remains controversial. In this review, we highlight preliminary data with several cytokines and chemokines, including GM-CSF, interleukin 12, FMS-like tyrosine kinase 3 ligand, tumor necrosis factor α, interleukin 2, interleukin 15, interleukin 18, chemokine (C-C motif) ligand 2, chemokine (C-C motif) ligand 5, chemokine (C-X-C motif) ligand 4, or their combinations, and show how these payloads can further enhance the antitumor immunity of oHSV. A better understanding of cytokine delivery by oHSV can help improve clinical benefit from oncolytic virus immunotherapy in patients with cancer.

EXPRESSION OF CONCERN: Therapeutic targeting of chemoresistant and recurrent glioblastoma stem cells with a proapoptotic variant of oncolytic herpes simplex virus.

EXPRESSION OF CONCERN: Nusrat Jahan, Jae M. Lee, Khalid Shah, Hiroaki Wakimoto, "Therapeutic targeting of chemoresistant and recurrent glioblastoma stem cells with a proapoptotic variant of oncolytic herpes simplex virus", International Journal of Cancer 141, no. 8 (2017): 1671-1681. https://doi.org/10.1002/ijc.30811. This Expression of Concern is for the above article, published online on 31 May 2017, in Wiley Online Library (wileyonlinelibrary.com), and has been published by agreement between the authors, the journal's Editor-in-Chief, Christoph Plass, the Union for International Cancer Control and John Wiley & Sons, Ltd. The Expression of Concern has been agreed following concerns raised regarding figure 4g and 5d. The Control (PBS) 4X DAPI image in figure 5d was found to contain elements similar to the Control (PBS) DAPI image presented in figure 4g. The authors admitted that they had mistakenly supplied the incorrect image to represent DAPI in figure 5d. Since the original DAPI image for figure 5d is no longer available, this issue could not be resolved. The journal has decided to issue an Expression of Concern to alert the readers.

Exogenous non-coding dsDNA-dependent trans-activation of phagocytes augments anti-tumor immunity.

Stimulator of interferon genes (STING)-dependent signaling is requisite for effective anti-microbial and anti-tumor activity. STING signaling is commonly defective in cancer cells, which enables tumor cells to evade the immunosurveillance system. We evaluate here whether intrinsic STING signaling in such tumor cells could be reconstituted by creating recombinant herpes simplex viruses (rHSVs) that express components of the STING signaling pathway. We observe that rHSVs expressing STING and/or cGAS replicate inefficiently yet retain in vivo anti-tumor activity, independent of oncolytic activity requisite on the trans-activation of extrinsic STING signaling in phagocytes by engulfed microbial dsDNA species. Accordingly, the in vivo effects of virotherapy could be simulated by nanoparticles incorporating non-coding dsDNA species, which comparably elicit the trans-activation of phagocytes and augment the efficacy of established cancer treatments including checkpoint inhibition and radiation therapy. Our results help elucidate mechanisms of virotherapeutic anti-tumor activity as well as provide alternate strategies to treat cancer.

PCR testing for herpesviruses in aqueous humor samples from patients with and without clinical corneal endothelial graft rejection.

To compare prevalence of positive PCR tests for herpesviruses between patients with and without a history of clinical corneal endothelial allograft rejection (AGR). Retrospective cross-sectional study with two-group comparison. A total of 307 aqueous humor (AH) samples from 235 Patients and 244 eyes who underwent penetrating keratoplasty or Descemet membrane endothelial keratoplasty or had a diagnostic AH aspiration due to clinical AGR between 2019 and 2023 were tested for DNA of herpes simplex virus (HSV), varicella-zoster virus (VZV), cytomegalovirus (CMV), and Epstein-Barr virus (EBV). PCR test results were compared between the two groups (with/without AGR). Another sub-analysis examined the results of patients without a history of herpetic keratitis. A total of 8% of eyes with clinical AGR (9/108) had a positive PCR result for one of the herpesviruses (HSV:3, CMV:3, EBV:2, VZV:1). All patients in the group without AGR had negative PCR results for all previous viruses (0/136). The difference was statistically significant (p < 0.001). The sub-analysis of eyes without a history of herpetic keratitis also revealed significantly more positive herpes PCR results (7/87) in eyes with AGR than in eyes without AGR (0/42, p = 0.005). Clinical AGR after keratoplasty shows a significant correlation to viral replication. Herpetic infection and AGR could occur simultaneously and act synergistically. Timely differentiation between active herpetic infection and/or AGR is pivotal for proper treatment and graft preservation.

Overcoming therapeutic resistance in oncolytic herpes virotherapy by targeting IGF2BP3-induced NETosis in malignant glioma.

Oncolytic virotherapy holds promise for cancer treatment, but the factors determining its oncolytic activity remain unclear. Neutrophil extracellular traps (NETs) are associated with cancer progression, yet their formation mechanism and role in oncolytic virotherapy remain elusive. In this study, we demonstrate that, in glioma, upregulation of IGF2BP3 enhances the expression of E3 ubiquitin protein ligase MIB1, promoting FTO degradation via the ubiquitin-proteasome pathway. This results in increased m6A-mediated CSF3 release and NET formation. Oncolytic herpes simplex virus (oHSV) stimulates IGF2BP3-induced NET formation in malignant glioma. In glioma models in female mice, a BET inhibitor enhances the oncolytic activity of oHSV by impeding IGF2BP3-induced NETosis, reinforcing virus replication through BRD4 recruitment with the CDK9/RPB-1 complex to HSV gene promoters. Our findings unveil the regulation of m6A-mediated NET formation, highlight oncolytic virus-induced NETosis as a critical checkpoint hindering oncolytic potential, and propose targeting NETosis as a strategy to overcome resistance in oncolytic virotherapy.

Heterogenous circulating miRNA changes in ME/CFS converge on a unified cluster of target genes: A computational analysis.

Myalgic Encephalomyelitis / Chronic Fatigue Syndrome is a debilitating, multisystem disease of unknown mechanism, with a currently ongoing search for its endocrine mediators. Circulating microRNAs (miRNA) are a promising candidate for such a mediator and have been reported as significantly different in the patient population versus healthy controls by multiple studies. None of these studies, however, agree with each other on which specific miRNA are under- or over-expressed. This discrepancy is the subject of the computational study presented here, in which a deep dive into the predicted gene targets and their functional interactions is conducted, revealing that the aberrant circulating miRNAs in ME/CFS, although different between patients, seem to mainly target the same specific set of genes (p ≈ 0.0018), which are very functionally related to each other (p ≲ 0.0001). Further analysis of these functional relations, based on directional pathway information, points to impairments in exercise hyperemia, angiogenic adaptations to hypoxia, antioxidant defenses, and TGF-ß signaling, as well as a shift towards mitochondrial fission, corroborating and explaining previous direct observations in ME/CFS. Many transcription factors and epigenetic modulators are implicated as well, with currently uncertain downstream combinatory effects. As the results show significant similarity to previous research on latent herpesvirus involvement in ME/CFS, the possibility of a herpesvirus origin of these miRNA changes is also explored through further computational analysis and literature review, showing that 8 out of the 10 most central miRNAs analyzed are known to be upregulated by various herpesviruses. In total, the results establish an appreciable and possibly central role for circulating microRNAs in ME/CFS etiology that merits further experimental research.

The Quest for Immunity: Exploring Human Herpesviruses as Vaccine Vectors.

Herpesviruses are large DNA viruses that have long been used as powerful gene therapy tools. In recent years, the ability of herpesviruses to stimulate both innate and adaptive immune responses has led to their transition to various applications as vaccine vectors. This vaccinology branch is growing at an unprecedented and accelerated rate. To date, human herpesvirus-based vectors have been used in vaccines to combat a variety of infectious agents, including the Ebola virus, foot and mouth disease virus, and human immunodeficiency viruses. Additionally, these vectors are being tested as potential vaccines for cancer-associated antigens. Thanks to advances in recombinant DNA technology, immunology, and genomics, numerous steps in vaccine development have been greatly improved. A better understanding of herpesvirus biology and the interactions between these viruses and the host cells will undoubtedly foster the use of herpesvirus-based vaccine vectors in clinical settings. To overcome the existing drawbacks of these vectors, ongoing research is needed to further advance our knowledge of herpesvirus biology and to develop safer and more effective vaccine vectors. Advanced molecular virology and cell biology techniques must be used to better understand the mechanisms by which herpesviruses manipulate host cells and how viral gene expression is regulated during infection. In this review, we cover the underlying molecular structure of herpesviruses and the strategies used to engineer their genomes to optimize capacity and efficacy as vaccine vectors. Also, we assess the available data on the successful application of herpesvirus-based vaccines for combating diseases such as viral infections and the potential drawbacks and alternative approaches to surmount them.

Advances in oncolytic herpes simplex virus and adenovirus therapy for recurrent glioma.

Recurrent glioma treatment is challenging due to molecular heterogeneity and treatment resistance commonly observed in these tumors. Researchers are actively pursuing new therapeutic strategies. Oncolytic viruses have emerged as a promising option. Oncolytic viruses selectively replicate within tumor cells, destroying them and stimulating the immune system for an enhanced anticancer response. Among Oncolytic viruses investigated for recurrent gliomas, oncolytic herpes simplex virus and oncolytic adenovirus show notable potential. Genetic modifications play a crucial role in optimizing their therapeutic efficacy. Different generations of replicative conditioned oncolytic human adenovirus and oncolytic HSV have been developed, incorporating specific modifications to enhance tumor selectivity, replication efficiency, and immune activation. This review article summarizes these genetic modifications, offering insights into the underlying mechanisms of Oncolytic viruses' therapy. It also aims to identify strategies for further enhancing the therapeutic benefits of Oncolytic viruses. However, it is important to acknowledge that additional research and clinical trials are necessary to establish the safety, efficacy, and optimal utilization of Oncolytic viruses in treating recurrent glioblastoma.

The expression and function of HSV ICP47 and its promoter in mice.

IMPORTANCE: Immune evasion and latency are key mechanisms that underlie the success of herpesviruses. In each case, interactions between viral and host proteins are required and due to co-evolution, not all mechanisms are preserved across host species, even if infection is possible. This is highlighted by the herpes simplex virus (HSV) protein immediate early-infected cell protein (ICP)47, which inhibits the detection of infected cells by killer T cells and acts with high efficiency in humans, but poorly, if at all in mouse cells. Here, we show that ICP47 retains modest but detectable function in mouse cells, but in an in vivo model we found no role during acute infection or latency. We also explored the activity of the ICP47 promoter, finding that it could be active during latency, but this was dependent on genome location. These results are important to interpret HSV pathogenesis work done in mice.

Evidence of a Protein-Coding Gene Antisense to the UL5 Gene in Bovine Herpesvirus I.

Bovine herpesvirus type 1 (BoHV-1) is an important agricultural pathogen that infects cattle and other ruminants worldwide. Though it was first sequenced and annotated over twenty years ago, the Cooper strain, used in this study, was sequenced as recently as 2012 and is currently said to encode 72 unique proteins. However, tandem mass spectrometry has identified several peptides produced during active infection that align with the BoHV-1 genome in unannotated regions. One of these abundant peptides, "ORF M", aligned antisense to the DNA helicase/primase protein UL5. This study characterizes the novel transcript and its protein product and provides evidence to support the existence of homolog protein-coding genes in other Herpesviruses.

Inactivation of the DNA-sensing pathway facilitates oncolytic herpes simplex virus inhibition of pancreatic ductal adenocarcinoma growth.

Oncolytic viruses are a new class of therapeutic agents for the treatment of cancer that have shown promising results in clinical trials. Oncolytic virus-mediated tumor rejection is highly dependent on viral replication in tumor cells to induce cell death. However, the antiviral immune response of tumor cells limits the replication capacity of oncolytic viruses. We hypothesized that inhibition of the antiviral immune response in infected cells would enhance the antitumor effect. Here, we confirmed that ablation of the key adaptor protein of cellular immunity, STING, significantly suppressed the antiviral immune response and promoted oncolytic herpes simplex virus-1 (oHSV1) proliferation in tumor cells. In a murine pancreatic ductal adenocarcinoma (PDAC) model, oHSV1 enhanced tumor suppression and prolonged the survival of mice in the absence of STING. On this basis, we further found that the TBK1 inhibitor can also significantly enhance the tumor-control ability of oHSV1. Our studies provide a novel strategy for oncolytic virus therapy by inhibiting the intrinsic antiviral response in solid tumors to improve antitumor efficacy.

Oncolytic virotherapies for pediatric tumors.

INTRODUCTION: Many pediatric patients with malignant tumors continue to suffer poor outcomes. The current standard of care includes maximum safe surgical resection followed by chemotherapy and radiation which may be associated with considerable long-term morbidity. The emergence of oncolytic virotherapy (OVT) may provide an alternative or adjuvant treatment for pediatric oncology patients. AREAS COVERED: We reviewed seven virus types that have been investigated in past or ongoing pediatric tumor clinical trials: adenovirus (AdV-tk, Celyvir, DNX-2401, VCN-01, Ad-TD-nsIL-12), herpes simplex virus (G207, HSV-1716), vaccinia (JX-594), reovirus (pelareorep), poliovirus (PVSRIPO), measles virus (MV-NIS), and Senecavirus A (SVV-001). For each virus, we discuss the mechanism of tumor-specific replication and cytotoxicity as well as key findings of preclinical and clinical studies. EXPERT OPINION: Substantial progress has been made in the past 10 years regarding the clinical use of OVT. From our review, OVT has favorable safety profiles compared to chemotherapy and radiation treatment. However, the antitumor effects of OVT remain variable depending on tumor type and viral agent used. Although the widespread adoption of OVT faces many challenges, we are optimistic that OVT will play an important role alongside standard chemotherapy and radiotherapy for the treatment of malignant pediatric solid tumors in the future.

Bifidobacterium infantis-Mediated Herpes Simplex Virus-TK/Ganciclovir Treatment Inhibits Cancer Metastasis in Mouse Model.

Previous studies have found that Bifidobacterium infantis-mediated herpes simplex virus-TK/ganciclovir (BF-TK/GCV) reduces the expression of VEGF and CD146, implying tumor metastasis inhibition. However, the mechanism by which BF-TK/GCV inhibits tumor metastasis is not fully studied. Here, we comprehensively identified and quantified protein expression profiling for the first time in gastric cancer (GC) cells MKN-45 upon BF-TK/GCV treatment using quantitative proteomics. A total of 159 and 72 differential expression proteins (DEPs) were significantly changed in the BF-TK/GCV/BF-TK and BF-TK/GCV/BF/GCV comparative analysis. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis enriched some metastasis-related pathways such as gap junction and cell adhesion molecules pathways. Moreover, the transwell assay proved that BF-TK/GCV inhibited the invasion and migration of tumor cells. Furthermore, immunohistochemistry (IHC) demonstrated that BF-TK/GCV reduced the expression of HIF-1α, mTOR, NF-κB1-p105, VCAM1, MMP13, CXCL12, ATG16, and CEBPB, which were associated with tumor metastasis. In summary, BF-TK/GCV inhibited tumor metastasis, which deepened and expanded the understanding of the antitumor mechanism of BF-TK/GCV.

Therapeutic effects against high-grade glioblastoma mediated by engineered induced neural stem cells combined with GD2-specific CAR-NK.

PURPOSE: High-grade glioblastoma is extremely challenging to treat because of its aggressiveness and resistance to conventional chemo- and radio-therapies. On the contrary, genetic and cellular immunotherapeutic strategies based on the stem and immune cells are emerging as promising treatments against glioblastoma (GBM). We aimed to developed a novel combined immunotherapeutic strategy to improve the treatment efficacy using genetically engineered PBMC-derived induced neural stem cells (iNSCs) expressing HSV-TK and second-generation CAR-NK cells against GBM. METHODS: iNSCs cells expressing HSV-TK (iNSCsTK) and GD2-specific CAR-NK92 (GD2NK92) were generated from PBMC-derived iNSCs and NK92 cell lines, respectively. The anti-tumor effect of iNSCsTK and the combinational therapeutics of iNSCsTK and GD2NK92 were evaluated by GBM cell line using in vitro and in vivo experiments. RESULTS: PBMC-derived iNSCsTK possessed tumor-tropism migration ability in vitro and in vivo, which exhibited considerable anti-tumor activity via bystander effect in the presence of ganciclovir (GCV). iNSCsTK/GCV could slow GBM progression and prolong median survival in tumor-bearing mice. However, the anti-tumor effect was limited to single therapy. Therefore, the combinational therapeutic effect of iNSCsTK/GCV and GD2NK92 against GBM was investigated. This approach displayed a more significant anti-tumor effect in vitro and in xenograft tumor mice. CONCLUSIONS: PBMC-derived iNSCsTK showed a significant tumor-tropic migration and an effective anti-tumor activity with GCV in vitro and in vivo. In addition, combined with GD2NK92, iNSCsTK therapeutic efficacy improved dramatically to prolong the tumor-bearing animal model's median survival.

Distinct role of CD8 cells and CD4 cells in antitumor immunity triggered by cell apoptosis using a Herpes simplex virus thymidine kinase/ganciclovir system.

Immune cells can recognize tumor-associated antigens released from dead tumor cells, which elicit immune responses, potentially resulting in tumor regression. Tumor cell death induced by chemotherapy has also been reported to activate immunity. However, various studies have reported drug-induced immunosuppression or suppression of inflammation by apoptotic cells. Thus, this study aimed to investigate whether apoptotic tumor cells trigger antitumor immunity independent of anticancer treatment. Local immune responses were evaluated after direct induction of tumor cell apoptosis using a Herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV) system. The inflammatory response was significantly altered at the tumor site after apoptosis induction. The expression of cytokines and molecules that activate and suppress inflammation simultaneously increased. The HSV-tk/GCV-induced tumor cell apoptosis resulted in tumor growth suppression and promoted T lymphocyte infiltration into tumors. Therefore, the role of T cells after inducing tumor cell death was explored. CD8 T cell depletion abrogated the antitumor efficacy of apoptosis induction, indicating that tumor regression was mainly dependent on CD8 T cells. Furthermore, CD4 T cell depletion inhibited tumor growth, suggesting the potential role of CD4 T cells in suppressive tumor immunity. Tumor tissues were evaluated after tumor cell apoptosis and CD4 T cell depletion to elucidate this immunological mechanism. Foxp3 and CTLA4, regulatory T-cell markers, decreased. Furthermore, arginase 1, an immune-suppressive mediator induced by myeloid cells, was significantly downregulated. These findings indicate that tumors accelerate CD8 T cell-dependent antitumor immunity and CD4 T cell-mediated suppressive immunity. These findings could be a therapeutic target for immunotherapy in combination with cytotoxic chemotherapy.

Oncolytic herpes simplex viruses for the treatment of glioma and targeting glioblastoma stem-like cells.

Glioblastoma (GBM) is one of the most lethal cancers, having a poor prognosis and a median survival of only about 15 months with standard treatment (surgery, radiation, and chemotherapy), which has not been significantly extended in decades. GBM demonstrates remarkable cellular heterogeneity, with glioblastoma stem-like cells (GSCs) at the apex. GSCs are a subpopulation of GBM cells that possess the ability to self-renew, differentiate, initiate tumor formation, and manipulate the tumor microenvironment (TME). GSCs are no longer considered a static population of cells with specific markers but are quite flexible phenotypically and in driving tumor heterogeneity and therapeutic resistance. In light of these features, they are a critical target for successful GBM therapy. Oncolytic viruses, in particular oncolytic herpes simplex viruses (oHSVs), have many attributes for therapy and are promising agents to target GSCs. oHSVs are genetically-engineered to selectively replicate in and kill cancer cells, including GSCs, but not normal cells. Moreover, oHSV can induce anti-tumor immune responses and synergize with other therapies, such as chemotherapy, DNA repair inhibitors, and immune checkpoint inhibitors, to potentiate treatment effects and reduce GSC populations that are partly responsible for chemo- and radio-resistance. Herein, we present an overview of GSCs, activity of different oHSVs, clinical trial results, and combination strategies to enhance efficacy, including therapeutic arming of oHSV. Throughout, the therapeutic focus will be on GSCs and studies specifically targeting these cells. Recent clinical trials and approval of oHSV G47Δ in Japan for patients with recurrent glioma demonstrate the efficacy and promise of oHSV therapy.