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.

Sepsis and multi-organ failure due to genital herpes in a healthy person.

Herpes simplex virus type 2 (HSV-2) is highly prevalent in several regions of the world and is the main pathogen causing genital herpes, which is transmitted almost exclusively through sexual contact. Systemically disseminated infections caused by HSV-2 are rare and most often seen in newborns, pregnant women, or immunocompromised populations. The virus can invade multiple organs and cause damage. In this paper, we present an extremely rare case of an immunocompetent 36-year-old male who came to our hospital with a high fever with abdominal pain and died of sepsis and multiple organ dysfunction syndrome within a short period. After the exclusion of common pathogens such as bacterial and fungal infections during hospitalization, metagenomic next generation sequencing of the patient's peripheral blood and ascites gave us the answer, and very high nucleic acid sequence counts of HSV-2 were detected in both his peripheral blood and ascites, confirming HSV-2 as the causative virus. In addition, this paper provides a brief review of the relevant literature.

An unusual co-reactivation of herpes genitalis and shingles in a young male with primary genital herpes in partner.

BACKGROUND: Herpes simplex virus type 2 (HSV-2) is the most common cause of genital ulcers in industrialized countries. Herpes zoster (HZ) is an acute, cutaneous viral infection caused by the reactivation of the varicella-zoster virus (VZV). CASE SUMMARY: A 27-year-old male presented with painful vesicles over the trunk for the last 5 days with painful genital erosions for the last 2 days. His spouse also developed painful genital erosions with systemic complaints for the last 2 days. VZV Polymerase Chain reaction (PCR) from trunk vesicles and type-specific anti-HSV antibody from serum were positive from the index case. DISCUSSION: Here, we report an unusual case of co-reactivation of herpes zoster and genitalis in an immunocompetent male. We recommend the use of molecular testing to confirm the diagnosis of VZV or HSV infection in all cases of genital herpes-like lesions to exclude multi-segmental herpes zoster.

Viral Shedding 1 Year Following First-Episode Genital HSV-1 Infection.

Importance: Herpes simplex virus type 1 (HSV-1) is the leading cause of first-episode genital herpes in many countries. Objective: To inform counseling messages regarding genital HSV-1 transmission, oral and genital viral shedding patterns among persons with first-episode genital HSV-1 infection were assessed. The trajectory of the development of HSV-specific antibody and T-cell responses was also characterized. Design, Setting, and Participants: Prospective cohort followed up for up to 2 years, with 82 participants followed up between 2013 and 2018. Participants were recruited from sexual health and primary care clinics in Seattle, Washington. Persons with laboratory-documented first-episode genital HSV-1 infection, without HIV infection or current pregnancy, were referred for enrollment. Exposures: First-episode genital HSV-1 infection. Main Outcomes and Measures: Genital and oral HSV-1 shedding and lesion rates at 2 months, 11 months, and up to 2 years after initial genital HSV-1 infection. Participants self-collected oral and genital swabs for HSV polymerase chain reaction testing for 30 days at 2 and 11 months and up to 2 years after diagnosis of genital HSV-1. Blood samples were collected at serial time points to assess immune responses to HSV-1. Primary HSV-1 infection was defined as absent HSV antibody at baseline or evolving antibody profile using the University of Washington HSV Western Blot. HSV-specific T-cell responses were detected using interferon γ enzyme-linked immunospot. Results: Among the 82 participants, the median (range) age was 26 (16-64) years, 54 (65.9%) were women, and 42 (51.2%) had primary HSV-1 infection. At 2 months, HSV-1 was detected from the genital tract in 53 participants (64.6%) and in the mouth in 24 participants (29.3%). Genital HSV-1 shedding was detected on 275 of 2264 days (12.1%) at 2 months and declined significantly to 122 of 1719 days (7.1%) at 11 months (model-predicted rate, 6.2% [95% CI, 4.3%-8.9%] at 2 months vs 3.2% [95% CI, 1.8%-5.7%] at 11 months; relative risk, 0.52 [95% CI, 0.29-0.93]). Genital lesions were rare, reported on 65 of 2497 days (2.6%) at 2 months and 72 of 1872 days (3.8%) at 11 months. Oral HSV-1 shedding was detected on 88 of 2247 days (3.9%) at 2 months. Persons with primary HSV-1 infection had a higher risk of genital shedding compared with those with nonprimary infection (model-predicted rate, 7.9% [95% CI, 5.4%-11.7%] vs 2.9% [95% CI, 1.7%-5.0%]; relative risk, 2.75 [95% CI, 1.40-5.44]). Polyfunctional HSV-specific CD4+ and CD8+ T-cell responses were maintained during the follow-up period. Conclusions and Relevance: Genital HSV-1 shedding was frequent after first-episode genital HSV-1, particularly among those with primary infection, and declined rapidly during the first year after infection.

Integrating network pharmacology and experimental validation to decipher the mechanism of the Chinese herbal prescription JieZe-1 in protecting against HSV-2 infection.

CONTEXT: The Chinese herbal prescription JieZe-1 (JZ-1) is effective against HSV-2 (Herpes simplex virus type 2) infection. However, its mechanism remains unclear. OBJECTIVE: To explore the mechanism of JZ-1 in protecting against HSV-2 infection. MATERIALS AND METHODS: Using the methods of network pharmacology, the hub components and targets were screened and functionally enriched. We established a genital herpes (GH) mouse model and observe the disease characteristics. Then, the GH mice in different groups (10 per/group) were treated with 20 µL JZ-1 gel (2.5, 1.5, and 0.5 g/mL), acyclovir gel (0.03 g/mL), or plain carbomer gel twice a day. The symptom score, vulvar histomorphology, and virus load were measured. The critical proteins of caspase-1-dependent pyroptosis were analysed by microscopy, co-immunoprecipitation, western blotting, and ELISA. Molecular docking was also performed. RESULTS: Network pharmacology analysis identified 388 JZ-1 targets related to HSV-2 infection, with 36 hub targets and 21 hub components screened. The TCID50 of HSV-2 was 1 × 10-7/0.1 mL. JZ-1 gel (2.5 g/mL) can effectively reduce the symptom score (81.23%), viral load (98.42%) and histopathological changes, and significantly inhibit the proteins expression of caspase-1-dependent pyroptosis in GH mice (p< 0.05). The molecular docking test showed a good binding potency between 11 components and caspase-1 or interleukin (IL)-1ß. DISCUSSION AND CONCLUSIONS: The present study demonstrated that JZ-1 protected mice from HSV-2 infection and inhibit the caspase-1-dependent pyroptosis in GH mice. It is of significance for the second development of JZ-1 and the exploration of new drugs.

Primary HSV-2 Infection in Early Pregnancy Results in Transplacental Viral Transmission and Dose-Dependent Adverse Pregnancy Outcomes in a Novel Mouse Model.

Herpes simplex virus type 2 (HSV-2) infection affects 24 million births annually and is associated with adverse pregnancy outcomes, including neonatal herpes; however, the mechanisms underlying in utero transmission of HSV-2 are largely unknown. We examined the effects of primary HSV-2 infection during early pregnancy on gestational outcomes in a novel, clinically relevant mouse model. Pregnant C57BL/6 mice were infected intravaginally with 102-105 pfu/mL HSV-2 on gestation day (gd) 4.5. Controls were infected, nonpregnant, diestrus-staged mice and pregnant, uninfected mice. Compared to nonpregnant mice, pregnant mice were 100-fold more susceptible to HSV-2 infection. Three days post-inoculation (gd7.5), viral DNA was present in implantation sites, but pregnancy outcomes were largely unaffected by infection. Eight days post-inoculation (gd12.5), HSV-2 DNA persisted in placental tissues, resulting in inflammation and hemorrhage. Fetal and placental weights were reduced and fetal loss was observed with high viral doses. HSV-2 DNA and increased expression of pro-inflammatory mediators were detected in fetal tissues at gd12.5, signifying viral transmission and fetal infection, even with low viral doses. This mouse model shows a dose-dependent effect of primary HSV-2 infection on pregnancy outcomes and suggests that fetal loss may occur due to placental inflammation, thus providing valuable insight into in utero transmission of HSV-2.

Tissue-Resident-Memory CD8+ T Cells Bridge Innate Immune Responses in Neighboring Epithelial Cells to Control Human Genital Herpes.

Tissue-resident-memory T cells (TRM) populate the body's barrier surfaces, functioning as frontline responders against reencountered pathogens. Understanding of the mechanisms by which CD8TRM achieve effective immune protection remains incomplete in a naturally recurring human disease. Using laser capture microdissection and transcriptional profiling, we investigate the impact of CD8TRM on the tissue microenvironment in skin biopsies sequentially obtained from a clinical cohort of diverse disease expression during herpes simplex virus 2 (HSV-2) reactivation. Epithelial cells neighboring CD8TRM display elevated and widespread innate and cell-intrinsic antiviral signature expression, largely related to IFNG expression. Detailed evaluation via T-cell receptor reconstruction confirms that CD8TRM recognize viral-infected cells at the specific HSV-2 peptide/HLA level. The hierarchical pattern of core IFN-γ signature expression is well-conserved in normal human skin across various anatomic sites, while elevation of IFI16, TRIM 22, IFITM2, IFITM3, MX1, MX2, STAT1, IRF7, ISG15, IFI44, CXCL10 and CCL5 expression is associated with HSV-2-affected asymptomatic tissue. In primary human cells, IFN-γ pretreatment reduces gene transcription at the immediate-early stage of virus lifecycle, enhances IFI16 restriction of wild-type HSV-2 replication and renders favorable kinetics for host protection. Thus, the adaptive immune response through antigen-specific recognition instructs innate and cell-intrinsic antiviral machinery to control herpes reactivation, a reversal of the canonical thinking of innate activating adaptive immunity in primary infection. Communication from CD8TRM to surrounding epithelial cells to activate broad innate resistance might be critical in restraining various viral diseases.

A sustained type I IFN-neutrophil-IL-18 axis drives pathology during mucosal viral infection.

Neutrophil responses against pathogens must be balanced between protection and immunopathology. Factors that determine these outcomes are not well-understood. In a mouse model of genital herpes simplex virus-2 (HSV-2) infection, which results in severe genital inflammation, antibody-mediated neutrophil depletion reduced disease. Comparative single-cell RNA-sequencing analysis of vaginal cells against a model of genital HSV-1 infection, which results in mild inflammation, demonstrated sustained expression of interferon-stimulated genes (ISGs) only after HSV-2 infection primarily within the neutrophil population. Both therapeutic blockade of IFNα/ß receptor 1 (IFNAR1) and genetic deletion of IFNAR1 in neutrophils concomitantly decreased HSV-2 genital disease severity and vaginal IL-18 levels. Therapeutic neutralization of IL-18 also diminished genital inflammation, indicating an important role for this cytokine in promoting neutrophil-dependent immunopathology. Our study reveals that sustained type I interferon (IFN) signaling is a driver of pathogenic neutrophil responses and identifies IL-18 as a novel component of disease during genital HSV-2 infection.

Herpes simplex virus (HSV) is a human pathogen that causes genital herpes, an incurable disease that results in recurrent sores and inflammation. Infection with HSV induces a strong antiviral immune response, which results in large numbers of immune cells arriving at these lesions. But while some of these cells help to control viral replication, others might contribute to the inflammation that drives the disease. One of the first immune cells to respond to infection are neutrophils. Although neutrophils are generally protective, especially against bacteria and fungi, they have also been implicated in tissue damage and severe inflammation during viral infections. But what determines whether a neutrophil will help to fight off an infection or increase disease severity is still an open question. To investigate this, Lebratti, Lim et al. studied mice that had been infected with the genital herpes virus HSV-2, which is known to cause significant amounts of inflammation in mice. The experiments revealed that a signaling molecule called type I interferon, which is thought to be antiviral, causes neutrophils at the site of the infection to produce proteins, such as IL-18, which trigger an inflammatory reaction. Lebratti, Lim et al. found that type I interferon and IL-18 had shifting roles during the course of infection. In the early stages, both molecules had a protective effect, confirming results from previous studies. However, as the infection progressed, sustained levels of type I interferon signaling in neutrophils led to excess amounts of IL-18. Lebratti, Lim et al. discovered that blocking interferon signaling or decreasing the levels of IL-18 later during infection unexpectedly reduced the severity of the disease and resulted in less genital tissue damage. Further experiments also showed that mice infected with another genital herpes virus called HSV-1 did not experience sustained levels of type I interferon. This may explain why this virus causes less severe disease in mice. Understanding how the immune system reacts to viruses could reveal new targets for treatments of genital herpes. At the moment, there is little information about IL-18 production during genital herpes in humans. So, the next step is to see whether neutrophils behave in the same way and whether IL-18 can be detected during human disease. It is possible that the same immune components could promote disease in other infections too. If so, this work may help uncover new drug targets for other viral diseases.

Herpesvirus encephalitis diagnosed by polymerase chain reaction at the National Institute of Neurology of Mexico.

The frequency of central nervous system infections due to herpesvirus have been studied in various populations; however, studies in Mexican mestizo patients are scant. This paper documents the frequency of herpesvirus encephalitis in Mexican mestizo patients from the National Institute of Neurology and Neurosurgery (NINN) of Mexico. To study the frequency of herpetic viral encephalitis at the NINN in the period from 2004 to 2009. We reviewed clinical records from patients with clinically suspected encephalitis; polymerase chain reaction assays were done for detection of herpesviruses in cerebrospinal fluid (CSF) samples. The total number of patients studied was 502; in 59 (12%), the diagnosis of herpetic encephalitis was confirmed by PCR-based testing of CSF. Of them, 21 (36%) were positive for herpes simplex virus type 1, 15 (25%) for Epstein-Barr virus, 10 (17%) for varicella zoster virus, 8 (14%) for cytomegalovirus, 3 (5%) for human herpesvirus 6, and 2 (3%) for herpes simplex virus 2. Our results show a varied frequency of viral encephalitis in mestizo patients due to herpesviruses in a tertiary neurological center and point out the importance of modern molecular technology to reach the etiological diagnosis in cases of encephalitis.

[The role of herpesviruses in development of diseases of the urogenital tract and infertility in women].

This review presents the data on the spreading of all known human herpesviruses (НHVs) in female urogenital tract. According to the WHO almost 500 million people worldwide suffer from genital infection caused by НHVs. НHVs were detected in various inflammatory diseases of female upper and lower genital tract (vaginitis and cervicitis), in extrauterine pregnancy (in fallopian tubes), in infertility (cervical channel, endometrium and ovaries). Herpes simplex virus 1 (HSV­1) was identified for the first time in oocytes after failed in vitro fertilization (IVF). НHVs produce negative effect on the entire reproductive process from conception to childbirth. It was established that HSV, cytomegalovirus (CMV) and human herpesvirus 6 (HHV-6) markedly increase the risk of spontaneous abortion, preterm birth and stillbirth. Intrauterine НHV infection is a major cause of congenital malformations. Data on humoral and cell immunity in genital herpesvirus infections (НHVI) are also reviewed. Intravaginal HSV­2 infection changes cell composition of vaginal mucosa, i.e., together with cells mobilized from the blood, protective role is performed by resident memory T­cells (TRM), natural killer cells (NK­cells) and regulatory T­cells (Treg) whose function consists in maintaining the balance of the activities of lymphocytes. Constant НHVI spreading is largely explained by transition of primary infection to potentially reactivating latent form, since latent virus is unavailable to immune recognition and medicines. The genome editing system CRISPR/Cas9 can recognize and modify not only active but also latent viruses. The promising pilot results with the use of this system offer the possibility of developing innovative technologies for НHV elimination and НHVI eradication.

Genital HSV-1 DNA detection is associated with a low inflammatory profile in HIV-uninfected South African women.

OBJECTIVES: Genital herpes simplex virus (HSV) infections are common in South Africa and worldwide. While HSV-2 is known to cause genital lesions, HSV-1 is better known to cause oral infections. Due to the global rise in genital HSV-1 infections, we aimed to compare the genital cytokine environment associated with HSV-1 and HSV-2 infections and their relation to the proinflammatory genital immune environment associated with HIV risk in African women. METHODS: HSV-1 and HSV-2 DNA were detected by quantitative real-time PCR in menstrual cup specimens collected from 251 HIV-negative women participating in the CAPRISA 083 study in Durban, South Africa. HSV shedding was defined as detection at >150 copies/mL. Forty-eight cytokines were measured in genital fluid by multiplexed ELISA, and multivariable regression models determined associations between genital cytokines and HSV DNA detection. RESULTS: HSV-1 DNA detection (24/251 (9.6%)) and shedding (13/24 (54.2%)) was more common than HSV-2 (detection in 14/251 (5.6%), shedding in 0/14). None of the women with detectable HSV had evidence of genital lesions. HSV-2 DNA detection was associated with increased interleukin (IL)-18 and decreased cutaneous T-cell attracting chemokine concentrations, but only in univariable analysis. By contrast, in both univariable and multivariable analyses, the detection of HSV-1 DNA was associated with reduced concentrations of granulocyte-colony stimulating factor, IL-7, IL-4, platelet-derived growth factor-ßß and five proinflammatory cytokines associated with HIV risk: IL-6, IL-1ß, macrophage inflammatory protein (MIP)-1α, MIP-1ß and tumour necrosis factor-α. CONCLUSIONS: That HSV-1 DNA was more commonly detected and shed than HSV-2 emphasises the need for clinical screening of both viruses, not just HSV-2 in young women. Efforts to reduce genital inflammation may need to consider implementing additional strategies to mitigate a rise in HSV replication.

Herpes Simplex Virus Serotyping in Pregnant Women With a History of Genital Herpes and an Outbreak in the Third Trimester of Pregnancy: A Cost-Effectiveness Analysis.

OBJECTIVE: To estimate whether serotyping women with a history of genital herpes simplex virus (HSV) and an outbreak during the third trimester of pregnancy is cost effective compared with no serotyping. METHODS: We designed a decision-analytic model using TreeAge Pro software to assess an approach of routine HSV serotyping in a theoretical cohort of 63,582 women (an estimate of the number of women in the United States with a history of genital HSV and an outbreak during the third trimester of pregnancy). Outcomes included mild, moderate, and severe neonatal HSV, neonatal death, costs, and quality-adjusted life-years (QALYs) for both the woman and neonate. Probabilities, utilities, and costs were derived from the literature, and we used a willingness-to-pay threshold of $100,000 per QALY. Sensitivity analyses were performed to assess the robustness of the results. RESULTS: In our theoretical cohort, HSV serology screening resulted in 519, 8, and 15 cases of mild, moderate, and severe neonatal HSV, whereas no serology screening resulted in 745, 65, and 85 cases, respectively. Thus, HSV serology screening led to 226, 57, and 70 fewer cases of mild, moderate, and severe neonatal HSV, respectively, as well as 91 fewer neonatal deaths. Additionally, serology screening saved $61 million and gained 7,900 QALYs, making it a dominant strategy. Univariate sensitivity analysis demonstrated that serology screening was cost effective until the chance of progression from neonatal HSV infection to disease despite empiric antiviral treatment was greater than 23%. CONCLUSION: Serology screening in pregnant women with an outbreak in the third trimester of pregnancy and a history of genital HSV resulted in improved outcomes and decreased costs.

T-type calcium channels blockers inhibit HSV-2 infection at the late stage of genome replication.

Herpes simplex virus type 2 (HSV-2) is a highly contagious sexually transmitted virus. The increasing emergence of drug-resistant viral strains has highlighted the crucial need for the development of new anti-HSV-2 drugs with different mechanisms. Ion channels that govern a wide range of cellular functions represent attractive targets for viral manipulation. Here, we tried to identify novel compounds to suppress HSV-2 infection in vitro by screening a small library with ion channels modulators. We found that several T-type calcium channel blockers including benidipine, lercanidipine, lomerizine and mibefradil inhibited HSV-2 infection, while L-type calcium channel blockers nifedipine and nitrendipine showed no significant effect on HSV-2 infection. Furthermore, we found that benidipine exerted the antiviral effect by suppressing the expression of viral genes in the late stage of viral infection. In conclusion, our study suggested that T-type calcium channel blockers, which are clinically wide used, could effectively inhibit HSV-2 infection. These findings could shed light on the mechanism and pharmacological study for HSV-2 infection in the future.

Subclinical Genital Herpes Shedding in HIV/Herpes Simplex Virus 2-Coinfected Women during Antiretroviral Therapy Is Associated with an Increase in HIV Tissue Reservoirs and Potentially Promotes HIV Evolution.

Antigen (Ag)-specific immune responses to chronic infections, such as herpes simplex virus type 2 (HSV-2) in HIV/HSV-coinfected persons, may sustain HIV tissue reservoirs by promoting T-cell proliferation but are poorly studied in women on antiretroviral therapy (ART). Mixed anogenital swabs and cervical secretions were self-collected by nine HIV/HSV-2-coinfected women during ART for 28 days to establish subclinical HSV DNA shedding rates and detection of HIV RNA by real-time PCR. Typical herpes lesion site biopsy (TLSB) and cervical biopsy specimens were collected at the end of the daily sampling period. Nucleic acids (NA) isolated from biopsy specimens had HIV quantified and HIV envC2-V5 single-genome amplification (SGA) and T-cell receptor (TCR) repertoires assessed. Women had a median CD4 count of 537 cells/µl (IQR: 483 to 741) at enrollment and HIV plasma viral loads of <40 copies/ml. HSV DNA was detected on 12% of days (IQR: 2 to 25%) from anogenital specimens. Frequent subclinical HSV DNA shedding was associated with increased HIV DNA tissue concentrations and increased divergence from the most recent common ancestor (MRCA), an indicator of HIV replication. Distinct predominant TCR clones were detected in cervical and TLSB specimens in a woman with frequent HSV DNA shedding, with mixing of minor variants between her tissues. In contrast, more limited TCR repertoire mixing was observed in two women with less frequent subclinical HSV DNA shedding. Subclinical HSV shedding in HIV/HSV-coinfected women during ART may sustain HIV tissue reservoirs via Ag exposure or HIV replication. This study provides evidence supporting further study of interventions targeting suppression of Ag-specific immune responses as a component of HIV cure strategies.IMPORTANCE Persons with HIV infection are frequently coinfected with chronic herpesviruses, which periodically replicate and produce viable herpes virions, particularly in anogenital and cervical tissues. Persistent protein expression results in proliferation of CD8+ and CD4+ T cells, and the latter could potentially expand and sustain HIV tissue reservoirs. We found HSV genital shedding rates were positively correlated with HIV DNA concentrations and HIV divergence from ancestral sequences in tissues. Our work suggests that immune responses to common coinfections, such as herpesviruses, may sustain HIV tissue reservoirs during suppressive ART, suggesting future cure strategies should study interventions to suppress replication or reactivation of chronic herpes infections.

Phosphoregulation of a Conserved Herpesvirus Tegument Protein by a Virally Encoded Protein Kinase in Viral Pathogenicity and Potential Linkage between Its Evolution and Viral Phylogeny.

Us3 proteins of herpes simplex virus 1 (HSV-1) and HSV-2 are multifunctional serine-threonine protein kinases. Here, we identified an HSV-2 tegument protein, UL7, as a novel physiological substrate of HSV-2 Us3. Mutations in HSV-2 UL7, which precluded Us3 phosphorylation of the viral protein, significantly reduced mortality, viral replication in the vagina, and development of vaginal disease in mice following vaginal infection. These results indicated that Us3 phosphorylation of UL7 in HSV-2 was required for efficient viral replication and pathogenicity in vivo Of note, this phosphorylation was conserved in UL7 of chimpanzee herpesvirus (ChHV), which phylogenetically forms a monophyletic group with HSV-2 and the resurrected last common ancestral UL7 for HSV-2 and ChHV. In contrast, the phosphorylation was not conserved in UL7s of HSV-1, which belongs to a sister clade of the monophyletic group, the resurrected last common ancestor for HSV-1, HSV-2, and ChHV, and other members of the genus Simplexvirus that are phylogenetically close to these viruses. Thus, evolution of Us3 phosphorylation of UL7 coincided with the phylogeny of simplex viruses. Furthermore, artificially induced Us3 phosphorylation of UL7 in HSV-1, in contrast to phosphorylation in HSV-2, had no effect on viral replication and pathogenicity in mice. Our results suggest that HSV-2 and ChHV have acquired and maintained Us3 phosphoregulation of UL7 during their evolution because the phosphoregulation had an impact on viral fitness in vivo, whereas most other simplex viruses have not because the phosphorylation was not necessary for efficient fitness of the viruses in vivoIMPORTANCE It has been hypothesized that the evolution of protein phosphoregulation drives phenotypic diversity across species of organisms, which impacts fitness during their evolution. However, there is a lack of information regarding linkage between the evolution of viral phosphoregulation and the phylogeny of virus species. In this study, we clarified the novel HSV-2 Us3 phosphoregulation of UL7 in infected cells, which is important for viral replication and pathogenicity in vivo We also showed that the evolution of Us3 phosphoregulation of UL7 was linked to the phylogeny of viruses that are phylogenetically close to HSV-2 and to the phosphorylation requirements for the efficient in vivo viral fitness of HSV-2 and HSV-1, which are representative of viruses that have and have not evolved phosphoregulation, respectively. This study reports the first evidence showing that evolution of viral phosphoregulation coincides with phylogeny of virus species and supports the hypothesis regarding the evolution of viral phosphoregulation during viral evolution.

An HSV-2 nucleoside-modified mRNA genital herpes vaccine containing glycoproteins gC, gD, and gE protects mice against HSV-1 genital lesions and latent infection.

HSV-1 causes 50% of first-time genital herpes infections in resource-rich countries and affects 190 million people worldwide. A prophylactic herpes vaccine is needed to protect against genital infections by both HSV-1 and HSV-2. Previously our laboratory developed a trivalent vaccine that targets glycoproteins C, D, and E present on the HSV-2 virion. We reported that this vaccine protects animals from genital disease and recurrent virus shedding following lethal HSV-2 challenge. Importantly the vaccine also generates cross-reactive antibodies that neutralize HSV-1, suggesting it may provide protection against HSV-1 infection. Here we compared the efficacy of this vaccine delivered as protein or nucleoside-modified mRNA immunogens against vaginal HSV-1 infection in mice. Both the protein and mRNA vaccines protected mice from HSV-1 disease; however, the mRNA vaccine provided better protection as measured by lower vaginal virus titers post-infection. In a second experiment, we compared protection provided by the mRNA vaccine against intravaginal challenge with HSV-1 or HSV-2. Vaccinated mice were totally protected against death, genital disease and infection of dorsal root ganglia caused by both viruses, but somewhat better protected against vaginal titers after HSV-2 infection. Overall, in the two experiments, the mRNA vaccine prevented death and genital disease in 54/54 (100%) mice infected with HSV-1 and 20/20 (100%) with HSV-2, and prevented HSV DNA from reaching the dorsal root ganglia, the site of virus latency, in 29/30 (97%) mice infected with HSV-1 and 10/10 (100%) with HSV-2. We consider the HSV-2 trivalent mRNA vaccine to be a promising candidate for clinical trials for prevention of both HSV-1 and HSV-2 genital herpes.

Use of the Guinea pig model of genital herpes to evaluate vaccines and antivirals: Review.

Herpes simplex virus (HSV) infections type 1 (HSV-1) and type 2 (HSV-2) are common throughout the world. Infections are lifelong and may produce both acute and recurrent vesiculoulcerative disease as well as more severe diseases. Despite disappointing results from recent HSV vaccine trials new vaccines and more potent antiviral therapies continue to be developed. These newer approaches require initial evaluations in animal models. In this review I have briefly described some of the models available and then more thoroughly describe the guinea pig model of acute and recurrent genital herpes infections. As discussed, the guinea pig model most closely mimics human disease and provides several important endpoints for evaluating vaccines and antivirals.