Management of Refractory/Resistant Herpes Simplex Virus Infections in Haematopoietic Stem Cell Transplantation Recipients: A Literature Review.

Herpes simplex virus (HSV) infections in allogeneic haematopoietic stem cell transplantation (HSCT) recipients pose significant challenges, with higher incidence, severity, and risk of emergence of resistance to antivirals due to impaired T-cell mediated immunity. This literature review focuses on acyclovir-refractory/resistant HSV infections in HSCT recipients. The review addresses the efficacy of antiviral prophylaxis, the incidence of acyclovir-refractory/resistant HSV infections, and the identification of risk factors and potential prognostic impact associated with those infections. Additionally, alternative therapeutic options are discussed. While acyclovir prophylaxis demonstrates a significant benefit in reducing HSV infections in HSCT recipients and, in some cases, overall mortality, concerns arise about the emergence of drug-resistant HSV strains. Our systematic review reports a median incidence of acyclovir-resistant HSV infections of 16.1%, with an increasing trend in recent years. Despite limitations in available studies, potential risk factors of emergence of HSV resistance to acyclovir include human leucocyte antigen (HLA) mismatches, myeloid neoplasms and acute leukaemias, and graft-versus-host disease (GVHD). Limited evidences suggest a potentially poorer prognosis for allogeneic HSCT recipients with acyclovir-refractory/resistant HSV infection. Alternative therapeutic approaches, such as foscarnet, cidofovir, topical cidofovir, optimised acyclovir dosing, and helicase-primase inhibitors offer promising options but require further investigations. Overall, larger studies are needed to refine preventive and therapeutic strategies for acyclovir-refractory/resistant HSV infections in allogeneic HSCT recipients and to identify those at higher risk.

Development of a highly effective combination monoclonal antibody therapy against Herpes simplex virus.

BACKGROUND: Infections with Herpes simplex virus (HSV)-1 or -2 usually present as mild chronic recurrent disease, however in rare cases can result in life-threatening conditions with a large spectrum of pathology. Monoclonal antibody therapy has great potential especially to treat infections with virus resistant to standard therapies. HDIT101, a humanized IgG targeting HSV-1/2 gB was previously investigated in phase 2 clinical trials. The aim of this study was to develop a next-generation therapy by combining different antiviral monoclonal antibodies. METHODS: A lymph-node derived phage display library (LYNDAL) was screened against recombinant gB from Herpes simplex virus (HSV) -1 and HDIT102 scFv was selected for its binding characteristics using bio-layer interferometry. HDIT102 was further developed as fully human IgG and tested alone or in combination with HDIT101, a clinically tested humanized anti-HSV IgG, in vitro and in vivo. T-cell stimulating activities by antigen-presenting cells treated with IgG-HSV immune complexes were analyzed using primary human cells. To determine the epitopes, the cryo-EM structures of HDIT101 or HDIT102 Fab bound to HSV-1F as well as HSV-2G gB protein were solved at resolutions < 3.5 Å. RESULTS: HDIT102 Fab showed strong binding to HSV-1F gB with Kd of 8.95 × 10-11 M and to HSV-2G gB with Kd of 3.29 × 10-11 M. Neutralization of cell-free virus and inhibition of cell-to-cell spread were comparable between HDIT101 and HDIT102. Both antibodies induced internalization of gB from the cell surface into acidic endosomes by binding distinct epitopes in domain I of gB and compete for binding. CryoEM analyses revealed the ability to form heterogenic immune complexes consisting of two HDIT102 and one HDIT101 Fab bound to one gB trimeric molecule. Both antibodies mediated antibody-dependent phagocytosis by antigen presenting cells which stimulated autologous T-cell activation. In vivo, the combination of HDIT101 and HDIT102 demonstrated synergistic effects on survival and clinical outcome in immunocompetent BALB/cOlaHsd mice. CONCLUSION: This biochemical and immunological study showcases the potential of an effective combination therapy with two monoclonal anti-gB IgGs for the treatment of HSV-1/2 induced disease conditions.

Gene editing for latent herpes simplex virus infection reduces viral load and shedding in vivo.

Anti-HSV therapies are only suppressive because they do not eliminate latent HSV present in ganglionic neurons, the source of recurrent disease. We have developed a potentially curative approach against HSV infection, based on gene editing using HSV-specific meganucleases delivered by adeno-associated virus (AAV) vectors. Gene editing performed with two anti-HSV-1 meganucleases delivered by a combination of AAV9, AAV-Dj/8, and AAV-Rh10 can eliminate 90% or more of latent HSV DNA in mouse models of orofacial infection, and up to 97% of latent HSV DNA in mouse models of genital infection. Using a pharmacological approach to reactivate latent HSV-1, we demonstrate that ganglionic viral load reduction leads to a significant decrease of viral shedding in treated female mice. While therapy is well tolerated, in some instances, we observe hepatotoxicity at high doses and subtle histological evidence of neuronal injury without observable neurological signs or deficits. Simplification of the regimen through use of a single serotype (AAV9) delivering single meganuclease targeting a duplicated region of the HSV genome, dose reduction, and use of a neuron-specific promoter each results in improved tolerability while retaining efficacy. These results reinforce the curative potential of gene editing for HSV disease.

Guías Latinoamericanas de Infecciones Congénitas y Perinatales de la Sociedad Latinoamericana de Infectología Pediátrica (SLIPE). Parte II / Latin American Guidelines on Congenital and Perinatal Infections from the Latin-American Society of Pediatric Infectious Diseases (SLIPE). Part II

Las infecciones perinatales son una causa de morbilidad, tanto fetal como neonatal, y que compromete la salud de la mujer embarazada, por lo que su diagnóstico, tratamiento, e intento de eliminación son una prioridad en América Latina y el Caribe. Este documento representa la segunda entrega realizada por expertos en la región dentro de la Sociedad Latinoamericana de Infectología Pediátrica (SLIPE), brindando una mirada actualizada en el manejo de las infecciones congénitas y entrega herramientas para detectar posibles momentos estratégicos de intervención y cambio en el manejo de las infecciones congénitas.

Perinatal infections are a major cause of morbidity and mortality in the fetus, neonate, and the health of the pregnant woman. Diagnosis, treatment, and the search for elimination of these diseases are a priority in Latin America and the Caribbean. This document represents the second delivery by a group of experts in the region inside the Latin-American Society of Pediatric Infectious Diseases (SLIPE), presenting a up-to-date look into the management of congenital infectious diseases and give a tool to detect possible strategic sceneries and a change in the management of congenital infections in our region.

Swarms of chemically modified antiviral siRNA targeting herpes simplex virus infection in human corneal epithelial cells.

Herpes simplex virus type 1 (HSV-1) is a common virus of mankind and HSV-1 infections are a significant cause of blindness. The current antiviral treatment of herpes infection relies on acyclovir and related compounds. However, acyclovir resistance emerges especially in the long term prophylactic treatment that is required for prevention of recurrent herpes keratitis. Earlier we have established antiviral siRNA swarms, targeting sequences of essential genes of HSV, as effective means of silencing the replication of HSV in vitro or in vivo. In this study, we show the antiviral efficacy of 2´-fluoro modified antiviral siRNA swarms against HSV-1 in human corneal epithelial cells (HCE). We studied HCE for innate immunity responses to HSV-1, to immunostimulatory cytotoxic double stranded RNA, and to the antiviral siRNA swarms, with or without a viral challenge. The panel of studied innate responses included interferon beta, lambda 1, interferon stimulated gene 54, human myxovirus resistance protein A, human myxovirus resistance protein B, toll-like receptor 3 and interferon kappa. Our results demonstrated that HCE cells are a suitable model to study antiviral RNAi efficacy and safety in vitro. In HCE cells, the antiviral siRNA swarms targeting the HSV UL29 gene and harboring 2´-fluoro modifications, were well tolerated, induced only modest innate immunity responses, and were highly antiviral with more than 99% inhibition of viral release. The antiviral effect of the 2'-fluoro modified swarm was more apparent than that of the unmodified antiviral siRNA swarm. Our results encourage further research in vitro and in vivo on antiviral siRNA swarm therapy of corneal HSV infection, especially with modified siRNA swarms.

A phase I/II study of triple-mutated oncolytic herpes virus G47∆ in patients with progressive glioblastoma.

Here, we report the results of a phase I/II, single-arm study (UMIN-CTR Clinical Trial Registry UMIN000002661) assessing the safety (primary endpoint) of G47∆, a triple-mutated oncolytic herpes simplex virus type 1, in Japanese adults with recurrent/progressive glioblastoma despite radiation and temozolomide therapies. G47Δ was administered intratumorally at 3 × 108 pfu (low dose) or 1 × 109 pfu (set dose), twice to identical coordinates within 5-14 days. Thirteen patients completed treatment (low dose, n = 3; set dose, n = 10). Adverse events occurred in 12/13 patients. The most common G47Δ-related adverse events were fever, headache and vomiting. Secondary endpoint was the efficacy. Median overall survival was 7.3 (95%CI 6.2-15.2) months and the 1-year survival rate was 38.5%, both from the last G47∆ administration. Median progression-free survival was 8 (95%CI 7-34) days from the last G47∆ administration, mainly due to immediate enlargement of the contrast-enhanced area of the target lesion on MRI. Three patients survived >46 months. One complete response (low dose) and one partial response (set dose) were seen at 2 years. Based on biopsies, post-administration MRI features (injection site contrast-enhancement clearing and entire tumor enlargement) likely reflected tumor cell destruction via viral replication and lymphocyte infiltration towards tumor cells, the latter suggesting the mechanism for "immunoprogression" characteristic to this therapy. This study shows that G47Δ is safe for treating recurrent/progressive glioblastoma and warrants further clinical development.

Implications of immune cells in oncolytic herpes simplex virotherapy for glioma.

Despite current progress in treatment, glioblastoma (GBM) remains a lethal primary malignant tumor of the central nervous system. Although immunotherapy has recently achieved remarkable survival effectiveness in multiple malignancies, none of the immune checkpoint inhibitors (ICIs) for GBM have shown anti-tumor efficacy in clinical trials. GBM has a characteristic immunosuppressive tumor microenvironment (TME) that results in the failure of ICIs. Oncolytic herpes simplex virotherapy (oHSV) is the most advanced United States Food and Drug Administration-approved virotherapy for advanced metastatic melanoma patients. Recently, another oHSV, Delytact®, was granted conditional approval in Japan against GBM, highlighting it as a promising treatment. Since oncolytic virotherapy can recruit abundant immune cells and modify the immune TME, oncolytic virotherapy for immunologically cold GBM will be an attractive therapeutic option for GBM. However, as these immune cells have roles in both anti-tumor and anti-viral immunity, fine-tuning of the TME using oncolytic virotherapy will be important to maximize the therapeutic efficacy. In this review, we discuss the current knowledge of oHSV, with a focus on the role of immune cells as friend or foe in oncolytic virotherapy.

Management of herpesvirus reactivations in patients with solid tumours and hematologic malignancies: update of the Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society for Hematology and Medical Oncology (DGHO) on herpes simplex virus type 1, herpes simplex virus type 2, and varicella zoster virus.

Clinical reactivations of herpes simplex virus or varicella zoster virus occur frequently among patients with malignancies and manifest particularly as herpes simplex stomatitis in patients with acute leukaemia treated with intensive chemotherapy and as herpes zoster in patients with lymphoma or multiple myeloma. In recent years, knowledge on reactivation rates and clinical manifestations has increased for conventional chemotherapeutics as well as for many new antineoplastic agents. This guideline summarizes current evidence on herpesvirus reactivation in patients with solid tumours and hematological malignancies not undergoing allogeneic or autologous hematopoietic stem cell transplantation or other cellular therapy including diagnostic, prophylactic, and therapeutic aspects. Particularly, strategies of risk adapted pharmacological prophylaxis and vaccination are outlined for different patient groups. This guideline updates the guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society for Hematology and Medical Oncology (DGHO) from 2015 "Antiviral prophylaxis in patients with solid tumours and haematological malignancies" focusing on herpes simplex virus and varicella zoster virus.

Eubacterium rectale Attenuates HSV-1 Induced Systemic Inflammation in Mice by Inhibiting CD83.

The purpose of this study was to determine whether administration of the microorganism Eubacterium rectale (E. rectale) could regulate dendritic cell (DC) activation and systemic inflammation in herpes simplex virus type 1-induced Behçet's disease (BD). E. rectale, butyrate-producing bacteria, was administered to BD mice. Peripheral blood leukocytes (PBL) and lymph node cells were isolated and analyzed by flow cytometry. 16S rRNA metagenomic analysis was performed in the feces of mice to determine the differences in the composition of the microbial population between normal and BD mice. Serum cytokine levels were measured by enzyme-linked immunosorbent assay. The frequency of DC activation marker CD83 positive cells was significantly increased in PBL of BD mice. Frequencies of CD83+ cells were also significantly increased in patients with active BD. 16S rRNA metagenomic analysis revealed different gut microbiota composition between normal and BD mice. The administration of E. rectale to BD mice reduced the frequency of CD83+ cells and significantly increased the frequency of NK1.1+ cells with the improvement of symptoms. The co-administration of colchicine and E. rectale also significantly reduced the frequency of CD83+ cells. Differences in gut microbiota were observed between normal mice and BD mice, and the administration of E. rectale downregulated the frequency of CD83, which was associated with BD deterioration. These data indicate that E. rectale could be a new therapeutic adjuvant for BD management.

Herpes Simplex Virus 1 Infection of Neuronal and Non-Neuronal Cells Elicits Specific Innate Immune Responses and Immune Evasion Mechanisms.

Alphaherpesviruses (α-HV) are a large family of double-stranded DNA viruses which cause many human and animal diseases. There are three human α-HVs: Herpes Simplex Viruses (HSV-1 and HSV-2) and Varicella Zoster Virus (VZV). All α-HV have evolved multiple strategies to suppress or exploit host cell innate immune signaling pathways to aid in their infections. All α-HVs initially infect epithelial cells (primary site of infection), and later spread to infect innervating sensory neurons. As with all herpesviruses, α-HVs have both a lytic (productive) and latent (dormant) stage of infection. During the lytic stage, the virus rapidly replicates in epithelial cells before it is cleared by the immune system. In contrast, latent infection in host neurons is a life-long infection. Upon infection of mucosal epithelial cells, herpesviruses immediately employ a variety of cellular mechanisms to evade host detection during active replication. Next, infectious viral progeny bud from infected cells and fuse to neuronal axonal terminals. Here, the nucleocapsid is transported via sensory neuron axons to the ganglion cell body, where latency is established until viral reactivation. This review will primarily focus on how HSV-1 induces various innate immune responses, including host cell recognition of viral constituents by pattern-recognition receptors (PRRs), induction of IFN-mediated immune responses involving toll-like receptor (TLR) signaling pathways, and cyclic GMP-AMP synthase stimulator of interferon genes (cGAS-STING). This review focuses on these pathways along with other mechanisms including autophagy and the complement system. We will summarize and discuss recent evidence which has revealed how HSV-1 is able to manipulate and evade host antiviral innate immune responses both in neuronal (sensory neurons of the trigeminal ganglia) and non-neuronal (epithelial) cells. Understanding the innate immune response mechanisms triggered by HSV-1 infection, and the mechanisms of innate immune evasion, will impact the development of future therapeutic treatments.

HSV-1-encoded ICP0 degrades the host deubiquitinase BRCC36 to antagonize interferon antiviral response.

Type I interferon (IFN-I) plays pivotal roles in defense against viral infection. HSV-1 has evolved multiple strategies to evade IFN-I antiviral response. In this study, we revealed a new mechanism that HSV-1-encoded ICP0 regulates the host deubiquitinase BRCC36 to inhibit IFN-I antiviral response. We found that HSV-1 infection rapidly downregulates BRCC36 proteins at the early stage of infection. Further studies demonstrated that HSV-1-encoded ICP0 induces K48-linked polyubiquitination and degradation of BRCC36. Importantly, HSV-1-induced BRCC36 degradation promotes downmodulation of IFN-I receptor IFNAR1, thus restricting host IFN-I antiviral response to facilitate HSV-1 early infection. These findings uncover a novel immune evasion mechanism exploited by HSV-1 and could provide potential strategies for anti-HSV-1 therapy.

Novel XTENylated AWRK6 analog with hypoglycemic activity, and anti-HSV-2 potential in combination with double shRNA.

AIMS: To design and evaluate a novel AWRK6 peptide-based long-acting GLP-1 receptor agonist (GLP-1RA) conjugated a recombinant polyethylene glycol mimetic (XTEN protein) with significant therapeutic potential on type 2 diabetes mellitus (T2DM) alone as well as Herpes simplex virus type 2 (HSV-2) infection in combination with double shRNA. MAIN METHODS: First, four AWRK6 analogs (termed XA-1 to XA-4) were designed and produced by solid phase synthesis strategy. Further surface plasmon resonance (SPR) measurement and in vitro cAMP accumulation assay were performed to detect the GLP-1R binding affinities and GLP-1R activation, respectively. The in vivo efficacy evaluation including pharmacokinetic test, oral glucose tolerance test (OGTT), hypoglycemic duration test and chronic pharmacodynamics study in rodent animals were all carefully performed. KEY FINDINGS: Four XA peptides were synthesized with purity >99%. High binding affinity as well as activation potency of XA-4 for GLP-1R were demonstrated by SPR and cell-based luciferase reporter assay, respectively. Additionally, XA-4 exhibited the long-lasting antidiabetic effects in the multiple OGTTs, hypoglycemic duration test and chronic study in mice. Furthermore, combined treatment of XA-4 and double shRNA (D-shRNA) achieved potent antiviral effects in HSV-2 infected HEK293 cells. SIGNIFICANCE: XA-4 exhibited promising pharmaceutical potential to be a therapeutic drug for treating T2D, and also held potential to against the HSV-2 infection, which is really an accidental discovery. The strategy of recombinant XTENylation can also be applied to other peptides or small molecules for the development of long-acting therapeutic drugs.

Management of Viral Complications of Pregnancy: Pharmacotherapy to Reduce Vertical Transmission.

Viral infections are common complications of pregnancy. Although some infections have maternal sequelae, many viral infections can be perinatally transmitted to cause congenital or chronic infection in fetuses or infants. Treatments of such infections are geared toward reducing maternal symptoms and complications and toward preventing maternal-to-child transmission of viruses. The authors review updates in the treatment of herpes simplex virus, cytomegalovirus, hepatitis B and C viruses, human immunodeficiency virus, and COVID-19 during pregnancy.

Postnatal Exposure to Herpes Simplex Virus: To Treat or Not to Treat?

Neonatal herpes simplex virus (HSV) infection carries significant morbidity and mortality. In contrast to perinatal exposure, there are no clear guidelines for the management of postnatal HSV exposure. This review focuses on the risk of HSV infection following postnatal exposure and suggests an approach to management. While many infants are protected by transplacentally transferred maternal anti-HSV antibodies, infants of seronegative mothers with significant postnatal HSV exposure may be at risk of severe disease. Individual risk assessment, appropriate investigations, and empiric acyclovir treatment should be considered in postnatally exposed newborns, even if asymptomatic. In all cases, close clinical follow-up is indicated, as well as education of families on the symptoms of neonatal HSV disease. Finally, measures to reduce the risk of postnatal HSV infection should be considered, such as discouraging individuals, particularly those with a history of recurrent cold sores, from kissing newborns.

Herpes Simplex Virus Type 1 Clinical Isolates Respond to UL29-Targeted siRNA Swarm Treatment Independent of Their Acyclovir Sensitivity.

Acyclovir is the drug of choice for the treatment of herpes simplex virus (HSV) infections. Acyclovir-resistant HSV strains may emerge, especially during long-term drug use, and subsequently cause difficult-to-treat exacerbations. Previously, we set up a novel treatment approach, based on enzymatically synthesized pools of siRNAs, or siRNA swarms. These swarms can cover kilobases-long target sequences, reducing the likelihood of resistance to treatment. Swarms targeting the UL29 essential gene of HSV-1 have demonstrated high efficacy against HSV-1 in vitro and in vivo. Here, we assessed the antiviral potential of a UL29 siRNA swarm against circulating strains of HSV-1, in comparison with acyclovir. All circulating strains were sensitive to both antivirals, with the half-maximal inhibitory concentrations (IC50) in the range of 350-1911 nM for acyclovir and 0.5-3 nM for the UL29 siRNA swarm. Additionally, we showed that an acyclovir-resistant HSV-1, devoid of thymidine kinase, is highly sensitive to UL29 siRNA treatment (IC50 1.0 nM; Imax 97%). Moreover, the detected minor variations in the RNAi target of the HSV strains had no effect on the potency or efficacy of UL29 siRNA swarm treatment. Our findings support the development of siRNA swarms for the treatment of HSV-1 infections, in order to circumvent any potential acyclovir resistance.

Premature Rupture of Membranes with Concurrent Viral Infection.

Treatment of viral infections is geared toward ameliorating maternal symptoms and minimizing perinatal transmission. Multidisciplinary teams often are required to manage sequelae due to viral diseases in patients with preterm premature rupture of membranes (PPROM). although data are scarce regarding the antepartum management of common viruses in PPROM, essential principles may be extrapolated from national guidelines and studies in gravid patients. The well-established risks of prematurity are weighed against the often unclear risks of vertical transmission.

Gene editing and elimination of latent herpes simplex virus in vivo.

We evaluate gene editing of HSV in a well-established mouse model, using adeno-associated virus (AAV)-delivered meganucleases, as a potentially curative approach to treat latent HSV infection. Here we show that AAV-delivered meganucleases, but not CRISPR/Cas9, mediate highly efficient gene editing of HSV, eliminating over 90% of latent virus from superior cervical ganglia. Single-cell RNA sequencing demonstrates that both HSV and individual AAV serotypes are non-randomly distributed among neuronal subsets in ganglia, implying that improved delivery to all neuronal subsets may lead to even more complete elimination of HSV. As predicted, delivery of meganucleases using a triple AAV serotype combination results in the greatest decrease in ganglionic HSV loads. The levels of HSV elimination observed in these studies, if translated to humans, would likely significantly reduce HSV reactivation, shedding, and lesions. Further optimization of meganuclease delivery and activity is likely possible, and may offer a pathway to a cure for HSV infection.

A 72-Year-Old Woman With Respiratory Failure and Bilateral Ground-Glass Opacities.

A 72-year-old woman with diabetes mellitus was admitted to our hospital because of dyspnea on exertion. Sputum cytologic evaluation revealed intranuclear inclusion bodies in the cells; we therefore considered viral pneumonia and performed a bronchoscopy. The bronchial washing fluid was positive for immunoperoxidase staining of herpes simplex virus type 1 (HSV1) and HSV1 polymerase chain reaction. The patient was diagnosed as having pneumonia due to HSV1 and was successfully treated with acyclovir.

Effect of Antiviral Therapy on the Outcome of Mechanically Ventilated Patients With Herpes Simplex Virus Type 1 in BAL Fluid: A Retrospective Cohort Study.

BACKGROUND: Herpes simplex virus type 1 (HSV-1) is frequently detected in the BAL fluid of patients on mechanical ventilation. RESEARCH QUESTION: The aim of the study was to investigate whether antiviral therapy is associated with improved overall survival within 30 days. STUDY DESIGN AND METHODS: This was a retrospective cohort study in four ICUs between January 2011 and December 2017. All adult patients on mechanical ventilation with a respiratory tract infection with positive polymerase chain reaction testing for HSV-1 in the BAL were included. Patients already receiving antiviral agents on the day BAL was performed were excluded. We performed uni- and multivariable Cox and logistic regression modeling. RESULTS: Overall, 306 patients were included in the analysis. Among them, 177 patients (57.8%) received antiviral therapy (90.9% acyclovir, 6.2% ganciclovir, 2.9% both). The overall 30-day mortality rate was 42.4% (n = 75) in the antiviral treatment group and 50.4% (n = 65) in the control group. The adjusted hazard ratio (HR) for the primary outcome was 0.62 (95% CI, 0.44-0.87; P = .005), indicating better overall survival within 30 days for the antiviral-treated group than for the untreated group. This benefit was also present in the subgroup of patients without immunosuppression (n = 246; adjusted HR, 0.53; 95% CI, 0.36-0.78; P = .001). Overall, the median lengths of hospital stay (31 vs 24 days, P = .002) and ICU stay (24 vs 17 days, P < .001), and the duration of mechanical ventilation (18 vs 11 days, P < .001), were longer for patients with therapy. No evidence for the treatment-related deterioration of renal function was observed. INTERPRETATION: These data suggest that detection of HSV-1 in the BAL of patients on mechanical ventilation may be of clinical significance and that specific antiviral treatment may improve clinical outcomes. However, this needs to be proven in multicenter randomized controlled trials before implementation into the clinical routine.