Herpes Simplex Virus Reactivation Research Articles

Herpes simplex virus and Cytomegalovirus reactivation among severe ARDS patients under veno-venous ECMO

BackgroundHerpesviridae reactivation among non-immunocompromised critically ill patients is associated with impaired prognosis, especially during acute respiratory distress syndrome (ARDS). However, little is known about herpes simplex virus (HSV) and Cytomegalovirus (CMV) reactivation occurring in patients with severe ARDS under veno-venous extracorporeal membrane oxygenation (ECMO). We tried to determine the frequency of Herpesviridae reactivation and its impact on patients’ prognosis during ECMO for severe ARDS.ResultsDuring a 5-year period, 123 non-immunocompromised patients with a severe ARDS requiring a veno-venous ECMO were included. Sixty-seven patients (54%) experienced HSV and/or CMV reactivation during ECMO course (20 viral co-infection, 40 HSV alone, and 7 CMV alone). HSV reactivation occurred earlier than CMV after the beginning of MV [(6–15) vs. 19 (13–29) days; p < 0.01] and after ECMO implementation [(2–8) vs. 14 (10–20) days; p < 0.01]. In univariate analysis, HSV/CMV reactivation was associated with a longer duration of mechanical ventilation [(22–52.5) vs. 17.5 (9–28) days; p < 0.01], a longer duration of ECMO [15 (10–22.5) vs. 9 (5–14) days; p < 0.01], and a prolonged ICU [29 (19.5–47.5) vs. 16 (9–30) days; p < 0.01] and hospital stay [44 (29–63.5) vs. 24 (11–43) days; p < 0.01] as compared to non-reactivated patients. However, in multivariate analysis, viral reactivation remained associated with prolonged MV only. When considered separately, both HSV and CMV reactivation were associated with a longer duration of MV as compared to non-reactivation patients [29 (19.5–41) and 28 (20.5–37), respectively, vs. 17.5 (9–28) days; p < 0.05]. Co-reactivation patients had a longer duration of MV [58.5 (38–72.3); p < 0.05] and ICU stay [51.5 (32.5–69) vs. 27.5 (17.75–35.5) and 29 (20–30.5), respectively] as compared to patients with HSV or CMV reactivation alone. In multivariate analysis, HSV reactivation remained independently associated with a longer duration of MV and hospital length of stay.ConclusionsHerpesviridae reactivation is frequent among patients with severe ARDS under veno-venous ECMO and is associated with a longer duration of mechanical ventilation. The direct causative link between HSV and CMV reactivation and respiratory function worsening under ECMO remains to be confirmed.

Herpes Simplex Virus 1 Replication, Ocular Disease, and Reactivations from Latency Are Restricted Unilaterally after Inoculation of Virus into the Lip.

Ocular herpes simplex keratitis (HSK) is a consequence of viral reactivations from trigeminal ganglia (TG) and occurs almost exclusively in the same eye in humans. In our murine oro-ocular (OO) model, herpes simplex virus 1 (HSV-1) inoculation in one side of the lip propagates virus to infect the ipsilateral TG. Replication here allows infection of the brainstem and infection of the contralateral TG. Interestingly, HSK was observed in our OO model only from the eye ipsilateral to the site of lip infection. Thus, unilateral restriction of HSV-1 may be due to differential kinetics of virus arrival in the ipsilateral versus contralateral TG. We inoculated mice with HSV-1 reporter viruses and then superinfected them to monitor changes in acute- and latent-phase gene expression in TG after superinfection compared to the control (single inoculation). Delaying superinfection by 4 days after initial right lip inoculation elicited failed superinfecting-virus gene expression and eliminated clinical signs of disease. Initial inoculation with thymidine kinase-deficient HSV-1 (TKdel) completely abolished reactivation of wild-type (WT) superinfecting virus from TG during the latent stage. In light of these seemingly failed infections, viral genome was detected in both TG. Our data demonstrate that inoculation of HSV-1 in the lip propagates virus to both TG, but with delay in reaching the TG contralateral to the side of lip infection. This delay is responsible for restricting viral replication to the ipsilateral TG, which abrogates ocular disease and viral reactivations from the contralateral side. These observations may help to understand why HSK is observed unilaterally in humans, and they provide insight into vaccine strategies to protect against HSK.IMPORTANCE Herpetic keratitis (HK) is the leading cause of blindness by an infectious agent in the developed world. This disease can occur after reactivation of herpes simplex virus 1 in the trigeminal ganglia, leading to dissemination of virus to, and infection of, the cornea. A clinical paradox is evidenced by the bilateral presence of latent viral genomes in both trigeminal ganglia, while for any given patient the disease is unilateral with recurrences in a single eye. Our study links the kinetics of early infection to unilateral disease phenomenon and demonstrates protection against viral reactivation when kinetics are exploited. Our results have direct implications in the understanding of human disease pathogenesis and immunotherapeutic strategies for the treatment of HK and viral reactivations.

Herpes simplex virus reactivation and the relationship with Alzheimer's disease: A countering view

AbstractMany have described the molecular mechanisms underpinning the viral etiology of Alzheimer's disease. This commentary challenges this premise by discussing evidence that Herpes simplex virus reactivation reduces progression to Alzheimer's disease, and also proposing that viral reactivation is a compensatory reaction to other causal exposures in Alzheimer's disease pathophysiology.

Concurrent reactivation of varicella zoster virus and herpes simplex virus in an immunocompetent elderly male

Concurrent reactivation of varicella zoster virus and herpes simplex virus in an immunocompetent elderly male

1410. Serious Cryptococcal Infections with Ruxolitinib Use: A Case of Meningitis and a Review of the Literature

BackgroundRuxolitinib is an inhibitor of Janus kinase (JAK) 1 and 2 and is approved for the treatment of myelofibrosis and polycythemia vera. Infectious complications associated with its use include reactivation of herpes simplex, zoster, hepatitis B, and tuberculosis, mucormycosis, and progressive multifocal leukoencephalopathy.MethodsSeven cases of ruxolitinib-associated cryptococcal infections have been reported: three cases of meningitis, two cases of pulmonary disease, and two cases of disseminated disease (Table 1).ResultsWe present a 72-year-old male with a history of JAK-2-positive polycythemia vera with secondary myelofibrosis, and concurrent multiple myeloma who presented with 3 weeks of chronic cough and 3 days of fever with severe bifrontal headache after remodeling a large birdcage in his backyard. The patient was on ruxolitinib, ixazomib, and weekly dexamethasone. Cerebrospinal fluid (CSF) analysis showed an elevated opening pressure of 29 cm of CSF, 173 leucocytes with a predominance of lymphocytes, protein of 87 mg/dL and a normal glucose level. BioFire FilmArray® Meningitis/Encephalitis panel detected targets for Cryptococcus in the CSF, and CSF cryptococcal antigen was positive at 1:4. CSF fungal cultures were subsequently positive for Cryptococcus neoformans, susceptible to liposomal amphotericin B (LAMB) and fluconazole. Ruxolitinib was discontinued, treatment with LAMB and flucytosine (5-FC) was associated with significant improvement of headache over the next week. Repeat CSF analysis in 2 weeks was culture negative with a negative cryptococcal antigen test. The patient completed 3 weeks of LAMB and 5-FC and then transitioned to oral fluconazole for a year.ConclusionRuloxitinib and other JAK inhibitors suppress host immunity through impaired T-cell activation and downregulation of cytokines. The JAK-Signal Transducer and Activator of Transcription pathway is one of the most active pathways in host defense against cryptococcus, and use of JAK inhibitors like ruxolitinib may predispose to severe cryptococcal infections. Bird exposure is a risk factor, making environmental contact counseling for patients on ruxolitinib important. Fluconazole prophylaxis needs to be considered in select cases. Disclosures All authors: No reported disclosures.

Effectiveness of dupilumab treatment in 95 patients with atopic dermatitis: daily practice data.

Dupilumab is the first biologic registered for the treatment of moderate-to-severe atopic dermatitis (AD), and efficacy was shown in phase III clinical trials (primary outcome at week 16 was reached in 38% of patients). Currently, there are limited daily practice data available for dupilumab, especially when it is combined with systemic immunosuppressants. To evaluate dupilumab treatment in daily practice in patients with AD. In this observational cohort study, we prospectively included all adult patients with AD who had been treated with dupilumab in two university hospitals in the Netherlands. Concomitant systemic immunosuppressive treatment was monitored. Physician-reported outcome measures and patient-reported outcome measures (PROMs) after ≥ 12 weeks of follow-up were analysed. We used a linear mixed-effects model to determine changes in scores during follow-up. Ninety-five patients were included. Of these, 62 patients were using systemic immunosuppressants at baseline; the use of systemic immunosuppressants was continued during dupilumab treatment in 43 patients. From baseline to 16 weeks of treatment, the estimated mean Eczema Area and Severity Index score (0-72) decreased from 18·6 [95% confidence interval (CI) 16·0-21·4)] to 7·3 (95% CI 5·4-10·0), and the estimated mean PROMs showed a decrease of 41-66%. Investigator's Global Assessment 0 or 1 (clear/almost clear) was reached in 38% of the patients. Five patients discontinued dupilumab treatment due to side-effects or ineffectiveness. Eye symptoms and orofacial (nonocular) herpes simplex virus (HSV) reactivation were reported in 62% and 8% of the patients, respectively. Dupilumab treatment in daily practice shows a clinically relevant improvement of physician-reported outcome measures and PROMs, which is in line with efficacy data from clinical trials. Besides frequently reported eye symptoms and orofacial (nonocular) HSV reactivation, there were no apparent safety concerns. What's already known about this topic? Dupilumab has been shown to be an efficacious treatment for atopic dermatitis in several clinical trials. However, it is known that there may be considerable differences in patient characteristics and treatment responses between clinical trials and daily practice. What does this study add? This study presents the first experience with dupilumab treatment in 95 patients with atopic dermatitis in daily practice in two Dutch university hospitals. Less stringent inclusion and exclusion criteria and follow-up schedules, in contrast to those used in clinical trials, might better represent daily practice. Dupilumab treatment shows a clinically relevant improvement of physician- and patient-reported outcome measures; besides patient-reported eye symptoms (in 59 of 95 patients; 62%) and an apparent increase in orofacial (nonocular) herpes simplex virus reactivation (eight of 95 patients; 8%), there were no other safety concerns during follow-up up to 16 weeks of dupilumab treatment.

The ICP0 Protein of Herpes Simplex Virus 1 (HSV-1) Downregulates Major Autophagy Adaptor Proteins Sequestosome 1 and Optineurin during the Early Stages of HSV-1 Infection.

Herpes simplex virus 1 (HSV-1) infects mucosal epithelial cells and establishes lifelong infections in sensory neurons. Following reactivation, the virus is transferred anterograde to the initial site of infection or to sites innervated by infected neurons, causing vesicular lesions. Upon immunosuppression, frequent HSV-1 reactivation can cause severe diseases, such as blindness and encephalitis. Autophagy is a process whereby cell components are recycled, but it also serves as a defense mechanism against pathogens. HSV-1 is known to combat autophagy through the functions of the γ134.5 protein, which prevents formation of the autophagophore by binding to Beclin 1, a key factor involved in the elongation of the isolation membrane, and by redirecting the protein phosphatase 1α (PP1α) to dephosphorylate the translation initiation factor 2α (eIF2α) to prevent host translational shutoff. Other viral proteins that counteract innate immunity negatively impact autophagy. Here, we present a novel strategy of HSV-1 to evade the host through the downregulation of the autophagy adaptor protein sequestosome (p62/SQSTM1) and of the mitophagy adaptor optineurin (OPTN). This down-modulation occurs during the early steps of the infection. We also found that infected cell protein 0 (ICP0) of the virus mediates the down-modulation of the two autophagy adaptors in a mechanism independent of its E3 ubiquitin ligase activity. Cells depleted of either p62 or OPTN were able to mount greater antiviral responses, whereas cells expressing exogenous p62 displayed decreased virus yields. We conclude that downregulation of p62/SQSTM1 and OPTN is a viral strategy to counteract the host.IMPORTANCE Autophagy is a homeostatic mechanism of cells to recycle components, as well as a defense mechanism to get rid of pathogens. Strategies that HSV-1 has developed to counteract autophagy have been described and involve inhibition of autophagosome formation or indirect mechanisms. Here, we present a novel mechanism that involves downregulation of two major autophagy adaptor proteins, sequestosome 1 (p62/SQSTM1) and optineurin (OPTN). These findings generate the question of why the virus targets two major autophagy adaptors if it has mechanisms to block autophagosome formation. P62/SQSTM1 and OPTN proteins have pleiotropic functions, including regulation of innate immunity, inflammation, protein sorting, and chromatin remodeling. The decrease in virus yields in the presence of exogenous p62/SQSTM1 suggests that these adaptors have an antiviral function. Thus, HSV-1 may have developed multiple strategies to incapacitate autophagy to ensure replication. Alternatively, the virus may target another antiviral function of these proteins.

The possibility of reactivation of herpes simplex virus as a result of photodynamic therapy — case report

Actinic keratosis (AK) is a common disorder, presented with scaly, erythematous lesions associated with chronic exposure to ultraviolet (UV) radiation and possible transforming into an invasive squamous cell carcinoma. Photodynamic Therapy (PDT) is one of non-invasive methods of treatment AK. We report the case of a 61-year-old female patient with AK treated with PDT in whom erythema and pustules with concomitant elevated body temperature were observed, what might indicate on reactivation of herpes simplex virus (HSV) infection.

The Role, Mechanism and Transcriptional Regulation of LAT in Herpes Simplex Virus Latency and Reactivation

Herpes simplex virus (HSV) infection in the human body can be latent in neurons for long time and be reactivated leading to recurrence at high rate. Currently there is no effective clinical strategy for the prevention and treatment of the disease relapse. HSV LAT gene is expressed in large quantities and lytic genes are turned off leading to HSV latency. Disruption of the gene expression is thought to cause HSV reactivation and disease relapse. To reveal the essence of HSV latency and reactivation, we summarized and innovatively classified the role, mechanism and transcriptional regulation of LAT in HSV latency and reactivation. This review may have important implications for future studies on HSV latency and reactivation, HSV disease prevention and treatment, and safer and more effective oncolytic HSVs (oHSVs).

Strong association between herpes simplex virus-1 and chemotherapy-induced oral mucositis in patients with hematologic malignancies.

Background/AimsA link between oral cavity infections and chemotherapy-induced oral mucositis (CIOM) in patients with hematological malignancies (HMs) undergoing intensive chemotherapy (IC) or hematopoietic stem cell transplantation (HSCT) has been suggested. However, conclusive data are lacking, and there are no current guidelines for the prophylactic use of antimicrobials to prevent CIOM in these populations.MethodsThe relationships between herpes simplex virus (HSV) reactivation and Candida colonization in the oral cavity and CIOM in patients with HMs undergoing IC or HSCT were evaluated. Patients aged ≥ 19 years with HMs undergoing IC or HSCT were enrolled. Each patient was evaluated for HSV and Candida in the oral cavity along with CIOM at baseline and during the 2nd, 3rd, and 4th weeks.ResultsSeventy presentations among 56 patients were analyzed. CIOM was observed in 23 presentations (32.9%), with a higher incidence associated with HSCT (17 of 35 presentations, 48.6%) than with IC (six of 35 presentations, 8.6%). The reactivation of HSV-1 was significantly associated with an increased incidence of CIOM after adjusting for age, sex, type of disease, and treatment stage. A higher HSV-1 viral load was associated with an increased incidence of CIOM. The presence of Candida was not associated with CIOM.ConclusionsHSV-1 reactivation in the oral cavity was highly associated with CIOM in patients with HMs undergoing high-dose chemotherapy.

Herpes simplex virus-1 (HSV-1) infection induces a potent but ineffective IFN-\u03bb production in immune cells of AD and PD patients

BackgroundThe sequential activation of immediate early (IE), early (E) and late (L) genes is required to allow productive herpes simplex virus type 1 (HSV-1) infection. Several evidences suggest that, together with inflammation, an immunological response incapable to counteract HSV-1 reactivation plays a role in the pathogenesis of Alzheimer’s (AD) and Parkinson’s (PD) diseases. IFN-lambda (IFN-λ), a cytokine endowed with a robust antiviral activity, contains HSV-1 reactivation. HSV-1-induced IFN-λ, IL-10 and IL-1β as well as the expression of viral IE, E and L genes were analyzed in vitro in peripheral blood mononuclear cells (PBMC) of AD and PD patients as well as of healthy controls (HC).MethodsPBMC of AD, PD and HC were in vitro infected with one multiplicity of infection (1 MOI) HSV-1. IE, E, and L viral genes transcription as well as IFN-λ, IL-10 and IL-1β production were analyzed.ResultsIn HSV-1-infected cells of AD and PD patients compared to HC: (1) transcription of IE (ICP0, ICP27) genes was reduced whereas that of E (UL41, UL29) and L (UL48, LAT) genes was increased; (2) IFN-λ mRNA expression was increased. IL-1β was augmented and IL-10 was reduced in unstimulated cells of AD and PD compared to HC; HSV-1 infection significantly increased IL-10 production in HC alone.ConclusionsData herein show that a proinflammatory condition is present in AD and PD, in whom attempts to obstacle viral replication via an initial, possibly more potent IFN-λ-mediated control of IE viral genes is unsuccessful.

Mechanisms of herpes simplex virus latency and reactivation

Herpes simplex virus (HSV), including HSV-1 and HSV-2, is an important pathogen that can cause many diseases. Usually these diseases are recurrent and incurable. After lytic infection on the surface of peripheral mucosa, HSV can enter sensory neurons and establish latent infection during which viral replication ceases. Moreover, latent virus can re-enter the replication cycle by reactivation and return to peripheral tissues to start recurrent infection. This ability to escape host immune surveillance during latent infection and to spread during reactivation is a viral survival strategy and the fundamental reason why no drug can completely eradicate the virus at present. Although there are many studies on latency and reactivation of HSV, and much progress has been made, many specific mechanisms of the process remain obscure or even controversial due to the complexity of this process and the limitations of research models. This paper reviews the major results of research on HSV latency and reactivation, and discusses future research directions in this field.

Disseminated zoster in an adult patient with extensive burns: a case report

BackgroundShingles (localized zoster) and disseminated zoster are caused by the reactivation of latent varicella zoster virus (VZV). Reactivation of VZV is related to impaired cell-mediated immunity. Extensive burns affecting a patient result in burn-related immunosuppression and cytokine storm. Despite immunosuppression in burn patients, the reactivation of VZV is extremely rare, whereas eczema herpeticum, caused by reactivation of latent herpes simplex virus (HSV), is common. We have found only 1 published case of VZV reactivation during burn treatment in the literature.Case presentationA 51-year-old man was burned in a fire, which affected 60% of his total body surface area (TBSA), and also received inhalation injury (day 0). Despite fluid resuscitation, he showed persistent renal failure. Continuous hemodialysis and filtration (CHDF) combined with polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) therapy was used for cytokine modulation. Autologous and allogeneic skin grafting was performed. On day 15, multiple-drug-resistant Pseudomonas aeruginosa (MDRP) was detected from a blood specimen, and the patient developed multiple organ failure (MOF). On day 31, compact aggregations of small vesicles appeared on the intact skin of his left knee and left buttock. The vesicles were located within the 4th lumbar (L4) spinal dermatome. From day 32 to day 34, similar new vesicles arose on his intact skin and epithelializing skin-graft donor sites. We diagnosed disseminated zoster, based on the patient’s age, the characteristic occurrence of the initial vesicles within a limited area of intact skin in the left L4 dermatome, and a positive Tzank smear. Serologic testing on day 36 showed a high level of anti-VZV immunoglobulin (Ig)G with low levels of anti-VZV IgM, anti-HSV IgG, and anti-HSV IgM. The patient was isolated in a negative-pressure room to avoid air-borne spread of VZV. On day 52, the patient died.ConclusionsTo the best of our knowledge, our patient is the second case of reactivation of VZV during burn treatment. It is unclear why reactivation of VZV is rare in patients with burn-related immunosuppression, whereas HSV reactivation is common. Cytokine modulation throughout the treatment period using CHDF combined with PMX-DHP might have been related to the rare reactivation of VZV in our patient. Our case provides an additional information on the relationship between the immune status of a patient with extensive burns and reactivation of latent VZV or HSV.

Impact of antiviral prophylaxis in HSV positive patients treated with concurrent chemoradiotherapy for head and neck cancer.

6078 Background: Chemoradiotherapy used for the treatment of locally advanced head and neck cancer (HNC) causes a high incidence of mucositis that may be accentuated by a reactivation of herpes simplex virus (HSV). To date, no study has evaluated the impact of antivirals used as prophylaxis to prevent mucositis or their severity. Methods: This is a retrospective observational study including patients who received at least one cycle of concurrent chemoradiotherapy for the treatment of head and neck cancer between January 2014 and June 2017 at the Centre hospitalier de l’Université de Montréal (CHUM). HSV negative patients were excluded. After approval by the IRB, we compared the incidence and severity of mucositis in HSV positive patients who started an antiviral prophylaxis before cycle 1 or 2 (prophylaxis group) to HSV+/unknown HSV patients who did not receive antiviral prophylaxis (control group). Emergency visits and hospitalizations related to mucositis were collected. Mucositis were assessed regularly by radiation oncologists during the treatment. Results: Of 482 patients who received concurrent chemoradiotherapy for HNC, 75 were HSV negative and 407 were included in this study. In the group with (n = 94) and without prophylaxis (n = 313), patients received carboplatin and 5-FU (77% vs 62%) and cisplatin (23% vs 38%) with concurrent radiation respectively. The rate of all grade mucositis in patients with and without prophylaxis (99% vs 96%; p = 0.19) was not statistically significant. The rate of grade 3 and 4 mucositis (42% vs 49%; p = 0.29), the rate of emergency visit (29% vs 28%; p = 0.91) and hospitalization (9% vs 8%; p = 0.80) were not statistically significant between each group. However, in a subgroup of patient receiving carboplatin and 5-FU, antiviral prophylaxis seems to decrease significantly the rate of grade 3 (49% vs 63%; p = 0.04). Conclusions: The addition of antiviral prophylaxis in HSV positive in patients undergoing concurrent chemoradiotherapy for locally advanced HNC didn’t decrease the rate of all grade mucositis. In the subgroup of patients receiving carboplatin and 5-FU mainly of oropharynx origin, HSV prophylaxis decreased the severity of mucositis.

Risk factors for herpes simplex virus type-1 infection and reactivation: Cross-sectional studies among EPIC-Norfolk participants.

BackgroundThe prevalence of, and risk factors for, herpes simplex virus type-1 (HSV-1) infection and reactivation in older individuals are poorly understood.MethodsThis is a prospective population-based study among community-dwelling individuals aged 40–79 years, followed from 1993, formed as a random subsample of the UK-based EPIC-Norfolk cohort. HSV-1 seropositivity was derived from immunoglobulin G measurements and frequent oro-labial HSV reactivation was self-reported. We carried out two cross-sectional studies using logistic regression to investigate childhood social and environmental conditions as risk factors for HSV-1 seropositivity and comorbidities as risk factors for apparent HSV oro-labial reactivation.ResultsOf 9,929 participants, 6310 (63.6%) were HSV-1 IgG positive, and 870 (of 4,934 seropositive participants with reactivation data) experienced frequent oro-labial reactivation. Being born outside the UK/Ireland, contemporaneous urban living and having ≥4 siblings were risk factors for HSV-1 seropositivity. Ever diagnosed with kidney disease, but no other comorbidities, was associated with an increased risk of frequent HSV reactivation (adjOR 1.87, 95%CI: 1.02–3.40).DiscussionApparent HSV-1 seropositivity and clinical reactivation are common within an ageing UK population. HSV-1 seropositivity is socially patterned while risk factors for oro-labial HSV reactivation are less clear. Further large studies of risk factors are needed to inform HSV-1 control strategies.

Therapeutic Mucosal Vaccination of Herpes Simplex Virus 2-Infected Guinea Pigs with Ribonucleotide Reductase 2 (RR2) Protein Boosts Antiviral Neutralizing Antibodies and Local Tissue-Resident CD4+ and CD8+ TRM Cells Associated with Protection against Recurrent Genital Herpes.

Reactivation of herpes simplex virus 2 (HSV-2) from latency causes viral shedding that develops into recurrent genital lesions. The immune mechanisms of protection against recurrent genital herpes remain to be fully elucidated. In this preclinical study, we investigated the protective therapeutic efficacy, in the guinea pig model of recurrent genital herpes, of subunit vaccine candidates that were based on eight recombinantly expressed HSV-2 envelope and tegument proteins. These viral protein antigens (Ags) were rationally selected for their ability to recall strong CD4+ and CD8+ T-cell responses from naturally "protected" asymptomatic individuals, who, despite being infected, never develop any recurrent herpetic disease. Out of the eight HSV-2 proteins, the envelope glycoprotein D (gD), the tegument protein VP22 (encoded by the UL49 gene), and ribonucleotide reductase subunit 2 protein (RR2; encoded by the UL40 gene) produced significant protection against recurrent genital herpes. The RR2 protein, delivered either intramuscularly or intravaginally with CpG and alum adjuvants, (i) boosted the highest neutralizing antibodies, which appear to cross-react with both gB and gD, and (ii) enhanced the numbers of functional gamma interferon (IFN-γ)-producing CRTAM+ CFSE+ CD4+ and CRTAM+ CFSE+ CD8+ TRM cells, which express low levels of PD-1 and TIM-3 exhaustion markers and were localized to healed sites of the vaginal mucocutaneous (VM) tissues. The strong B- and T-cell immunogenicity of the RR2 protein was associated with a significant decrease in virus shedding and a reduction in both the severity and frequency of recurrent genital herpes lesions. In vivo depletion of either CD4+ or CD8+ T cells significantly abrogated the protection. Taken together, these preclinical results provide new insights into the immune mechanisms of protection against recurrent genital herpes and promote the tegument RR2 protein as a viable candidate Ag to be incorporated in future genital herpes therapeutic mucosal vaccines.IMPORTANCE Recurrent genital herpes is one of the most common sexually transmitted diseases, with a global prevalence of HSV-2 infection predicted to be over 536 million worldwide. Despite the availability of many intervention strategies, such as sexual behavior education, barrier methods, and the costly antiviral drug treatments, eliminating or at least reducing recurrent genital herpes remains a challenge. Currently, no FDA-approved therapeutic vaccines are available. In this preclinical study, we investigated the immunogenicity and protective efficacy, in the guinea pig model of recurrent genital herpes, of subunit vaccine candidates that were based on eight recombinantly expressed herpes envelope and tegument proteins. We discovered that similar to the dl5-29 vaccine, based on a replication-defective HSV-2 mutant virus, which has been recently tested in clinical trials, the RR2 protein-based subunit vaccine elicited a significant reduction in virus shedding and a decrease in both the severity and frequency of recurrent genital herpes sores. This protection correlated with an increase in numbers of functional tissue-resident IFN-γ+ CRTAM+ CFSE+ CD4+ and IFN-γ+ CRTAM+ CFSE+ CD8+ TRM cells that infiltrate healed sites of the vaginal tissues. Our study sheds new light on the role of TRM cells in protection against recurrent genital herpes and promotes the RR2-based subunit therapeutic vaccine to be tested in the clinic.

Infectious Herpes Simplex Virus in the Brain Stem Is Correlated with Reactivation in the Trigeminal Ganglia.

Herpes simplex virus (HSV) establishes latency in neurons of the peripheral and central nervous systems (CNS). Evidence is mounting that HSV latency and reactivation in the nervous system has the potential to promote neurodegenerative processes. Understanding how this occurs is an important human health goal. In the mouse model, in vivo viral reactivation in the peripheral nervous system, triggered by hyperthermic stress, has been well characterized with respect to frequency and cell type. However, characterization of in vivo reactivation in the CNS is extremely limited. Further, it remains unclear whether virus reactivated in the peripheral nervous system is transported to the CNS in an infectious form, how often this occurs, and what parameters underlie the efficiency and outcomes of this process. In this study, reactivation was quantified in the trigeminal ganglia (TG) and the brain stem from the same latently infected animal using direct assays of equivalent sensitivity. Reactivation was detected more frequently in the TG than in the brain stem and, in all but one case, the amount of virus recovered was greater in the TG than that detected in the brain stem. Viral protein positive neurons were observed in the TG, but a cellular source for reactivation in the brain stem was not identified, despite serially sectioning and examining the entire tissue (0/6 brain stems). These findings suggest that infectious virus detected in the brain stem is primarily the result of transport of reactivated virus from the TG into the brain stem.IMPORTANCE Latent herpes simplex virus (HSV) DNA has been detected in the central nervous systems (CNS) of humans postmortem, and infection with HSV has been correlated with the development of neurodegenerative diseases. However, whether HSV can directly reactivate in the CNS and/or infectious virus can be transported to the CNS following reactivation in peripheral ganglia has been unclear. In this study, infectious virus was recovered from both the trigeminal ganglia and the brain stem of latently infected mice following a reactivation stimulus, but a higher frequency of reactivation and increased titers of infectious virus were recovered from the trigeminal ganglia. Viral proteins were detected in neurons of the trigeminal ganglia, but a cellular source of infectious virus could not be identified in the brain stem. These results suggest that infectious virus is transported from the ganglia to the CNS following reactivation but do not exclude the potential for direct reactivation in the CNS.

TOP2β-Dependent Nuclear DNA Damage Shapes Extracellular Growth Factor Responses via Dynamic AKT Phosphorylation to Control Virus Latency.

The mTOR pathway integrates both extracellular and intracellular signals and serves as a central regulator of cell metabolism, growth, survival, and stress responses. Neurotropic viruses, such as herpes simplex virus-1 (HSV-1), also rely on cellular AKT-mTORC1 signaling to achieve viral latency. Here, we define a novel genotoxic response whereby spatially separated signals initiated by extracellular neurotrophic factors and nuclear DNA damage are integrated by the AKT-mTORC1 pathway. We demonstrate that endogenous DNA double-strand breaks (DSBs) mediated by Topoisomerase 2β-DNA cleavage complex (TOP2βcc) intermediates are required to achieve AKT-mTORC1 signaling and maintain HSV-1 latency in neurons. Suppression of host DNA-repair pathways that remove TOP2βcc trigger HSV-1 reactivation. Moreover, perturbation of AKT phosphorylation dynamics by downregulating the PHLPP1 phosphatase led to AKT mis-localization and disruption of DSB-induced HSV-1 reactivation. Thus, the cellular genome integrity and environmental inputs are consolidated and co-opted by a latent virus to balance lifelong infection with transmission.

Lund Human Mesencephalic (LUHMES) Neuronal Cell Line Supports Herpes Simplex Virus 1 Latency In Vitro.

Lund human mesencephalic (LUHMES) cells are human embryonic neuronal precursor cells that can be maintained as proliferating cells due to the expression of a tetracycline-regulatable (Tet-off) v-myc transgene. They can be differentiated to postmitotic neurons by the addition of tetracycline, glial cell-derived neurotrophic factor (GDNF), and dibutyryl cAMP. We demonstrate that these cells can be infected with herpes simplex virus 1 (HSV-1) at a multiplicity of infection (MOI) of 3 with the majority of cells surviving. By 6 days postinfection, there is a loss of lytic gene transcription and an increase in the numbers of neurons that express the latency-associated transcripts (LATs). Importantly, the virus can then be reactivated by the addition of a phosphoinositide 3-kinase inhibitor, which has previously been shown to reactivate HSV-1 in rat neuron cultures. While rodent primary culture neuron systems have been described, these are limited by their lack of scalability, as it is difficult to obtain more than 500,000 neurons to employ for a given experiment. Several recent papers have described a human dorsal root ganglion (DRG) neuron culture model and human induced pleuripotent stem cell (iPSC) neuron culture models that are scalable, but they require that the presence of an antiviral suppression be maintained following HSV-1 infection. The human LUHMES cell model of HSV-1 infection described here may be especially useful for studying HSV-1 latency and reactivation on account of its scalability, its amenability to maintenance of latency without the continual use of antiviral inhibitors, and its latent gene expression profile which mirrors many properties observed in vivo, importantly, the heterogeneity of cells expressing the LATs.IMPORTANCE Herpes simplex virus (HSV) is responsible for significant morbidity in humans due to its ability to cause oral and genital lesions, ocular disease, and encephalitis. While antivirals can attenuate the severity and frequency of disease, there is no vaccine or cure. Understanding the molecular details of HSV latency and reactivation is key to the development of new therapies. One of the difficulties in studying HSV latency has been the need to rely on establishment of latent infections in animal models. While rodent primary neuron culture models have shown promise, they yield relatively small numbers of latently infected neurons for biochemical and molecular analyses. Here we present the use of a human central nervous system (CNS)-derived conditionally proliferating cell line that can be differentiated into mature neurons and latently infected with HSV-1. This model shows promise as a scalable tool to study molecular and biochemical aspects of HSV-1 latency and reactivation in human neurons.

Herpes Simplex Reactivation After Surgical Treatment of Trigeminal Neuralgia: A Retrospective Cohort Study

Herpes simplex virus (HSV) reactivation after surgery for trigeminal neuralgia has long been recognized. Only a few studies to date have focused on this complication, and its actual incidence remains unknown. The aim of this study was to investigate the incidence of postoperative herpes labialis (HL) in a cohort of patients treated with either percutaneous balloon compression or microvascular decompression to identify potentially significant differences between different treatments. A total of 92 patients who were operated on for TN with microvascular decompression (group A) or percutaneous balloon compression (group B) in the period 2010-2017 were retrospectively evaluated. The 2 subgroups of patients were compared according to history of previous HL and incidence of postoperative HL. The final cohort comprised 56 male and 36 female patients. Average age was 58.50 years; 30 male patients belonged to group A and 26 male patients belonged to group B. Lifetime incidence of episodes of HL before surgery in 18/58 patients in group A (31.0%) and 12/34 patients in group B (35.3%), with no statistically significant difference among subgroups. Postoperatively, 1/56 patients in group A (1.7%) experienced HL compared 5/34 patients in group B (14.7%), with a strongly statistically significant difference between the 2 subgroups. In our clinical experience, herpes simplex virus reactivation after surgery for trigeminal neuralgia is not so rare and is still not completely understood. Postoperative herpes simplex virus reactivation could be due to a direct mechanical injury on gasserian ganglion neurons, which is more common after percutaneous balloon compression.