Analysis of T cell responses during active varicella-zoster virus reactivation in human ganglia

Herpes zoster mRNA vaccine induces superior vaccine immunity over licensed vaccine in mice and rhesus macaques

Herpes zoster remains an important global health issue and mainly occurs in aged and immunocompromised individuals with an early exposure history to Varicella Zoster Virus (VZV). Although the licensed vaccine Shingrix has remarkably high efficacy, undesired reactogenicity and increasing global demand causing vaccine shortage urged the development of improved or novel VZV vaccines. In this study, we developed a novel VZV mRNA vaccine candidate (named as ZOSAL) containing sequence-optimized mRNAs encoding full-length glycoprotein E encapsulated in an ionizable lipid nanoparticle. In mice and rhesus macaques, ZOSAL demonstrated superior immunogenicity and safety in multiple aspects over Shingrix, especially in the induction of strong T-cell immunity. Transcriptomic analysis revealed that both ZOSAL and Shingrix could robustly activate innate immune compartments, especially Type-I IFN signalling and antigen processing/presentation. Multivariate correlation analysis further identified several early factors of innate compartments that can predict the magnitude of T-cell responses, which further increased our understanding of the mode of action of two different VZV vaccine modalities. Collectively, our data demonstrated the superiority of VZV mRNA vaccine over licensed subunit vaccine. The mRNA platform therefore holds prospects for further investigations in next-generation VZV vaccine development.

Heterologous Prime-Boost Immunization Strategies Using Varicella-Zoster Virus gE mRNA Vaccine and Adjuvanted Protein Subunit Vaccine Triggered Superior Cell Immune Response in Middle-Aged Mice

Purpose

Heterologous immunization using different vaccine platforms has been demonstrated as an efficient strategy to enhance antigen-specific immune responses. In this study, we performed a head-to-head comparison of both humoral and cellular immune response induced by different prime-boost immunization regimens of mRNA vaccine and adjuvanted protein subunit vaccine against varicella-zoster virus (VZV) in middle-aged mice, aiming to get a better understanding of the influence of vaccination schedule on immune response.

Methods

VZV glycoprotein (gE) mRNA was synthesized and encapsulated into SM-102-based lipid nanoparticles (LNPs). VZV-primed middle-aged C57BL/6 mice were then subjected to homologous and heterologous prime-boost immunization strategies using VZV gE mRNA vaccine (RNA-gE) and protein subunit vaccine (PS-gE). The antigen-specific antibodies were evaluated using enzyme-linked immunosorbent assay (ELISA) analysis. Additionally, cell-mediated immunity (CMI) was detected using ELISPOT assay and flow cytometry. Besides, in vivo safety profiles were also evaluated and compared.

Results

The mRNA-loaded lipid nanoparticles had a hydrodynamic diameter of approximately 130 nm and a polydispersity index of 0.156. Total IgG antibody levels exhibited no significant differences among different immunization strategies. However, mice received 2×RNA-gE or RNA-gE>PS-gE showed a lower IgG1/IgG2c ratio than those received 2×PS-gE and PS-gE> RNA-gE. The CMI response induced by 2×RNA-gE or RNA-gE>PS-gE was significantly stronger than that induced by 2×PS-gE and PS-gE> RNA-gE. The safety evaluation indicated that both mRNA vaccine and protein vaccine induced a transient body weight loss in mice. Furthermore, the protein vaccine produced a notable inflammatory response at the injection sites, while the mRNA vaccine showed no observable inflammation.

Conclusion

The heterologous prime-boost strategy has demonstrated that an mRNA-primed immunization regimen can induce a better cell-mediated immune response than a protein subunit-primed regimen in middle-aged mice. These findings provide valuable insights into the design and optimization of VZV vaccines with the potentials to broaden varicella vaccination strategies in the future.

Herpes zoster in neuro-ophthalmology: a practical approach

Herpes Zoster (HZ) or shingles is the reactivation of the Varicella Zoster Virus (VZV), usually along a single sensory nerve, but can affect both sensory and motor cranial nerves. Major risk factors for HZ include immunosuppressed status and age older than 60 years. In the United States, the lifetime risk of HZ is approximately 30%. Worldwide, the median incidence of HZ is 4-4.5 per 1000 person-years across the Americas, Eurasia, and Australia. HZ ophthalmicus, occurring in 10-20% of patients, is an ophthalmic emergency characterized by VZV reactivation along the V1 branch of the trigeminal nerve. Approximately half of this patient subgroup will go on to develop ocular manifestations, requiring prompt diagnosis and management. While anterior segment complications are more common, neuro-ophthalmic manifestations are rarer and can also occur outside the context of overt HZ ophthalmicus. Neuro-ophthalmic manifestations include optic neuropathy, acute retinal necrosis or progressive outer retinal necrosis, cranial neuropathy (isolated or multiple), orbitopathy, and CNS manifestations. Although typically a clinical diagnosis, diagnosis may be aided by neuroimaging and laboratory (e.g., PCR and serology) studies. Early antiviral therapy is indicated as soon as a presumptive diagnosis of VZV is made and the role of corticosteroids remains debated. Generally, there is wide variation of prognosis with neuro-ophthalmic involvement. Vaccine-mediated prevention is recommended. In this review, we summarize neuro-ophthalmic manifestations of VZV.

A Prognostic Model Incorporating Relevant Peripheral Blood Inflammation Indicator to Predict Postherpetic Neuralgia in Patients with Acute Herpes Zoster

Objective

To determine the risk of postherpetic neuralgia (PHN) in patients with acute herpes zoster (HZ), this study developed and validated a novel clinical prediction model by incorporating a relevant peripheral blood inflammation indicator.

Methods

Between January 2019 and June 2023, 209 patients with acute HZ were categorized into the PHN group (n = 62) and the non-PHN group (n = 147). Univariate and multivariate logistic regression analyses were conducted to identify risk factors serving as independent predictors of PHN development. Subsequently, a nomogram prediction model was established, and the discriminative ability and calibration were evaluated using the receiver operating characteristic curve, calibration plots, and decision curve analysis (DCA). The nomogram model was internally verified through the bootstrap test method.

Results

According to univariate logistic regression analyses, five variables, namely age, hypertension, acute phase Numeric Rating Scale (NRS-11) score, platelet-to-lymphocyte ratio (PLR), and systemic immune inflammation index, were significantly associated with PHN development. Multifactorial analysis further unveiled that age (odds ratio (OR) [95% confidence interval (CI)]: 2.309 [1.163-4.660]), acute phase NRS-11 score (OR [95% CI]: 2.837 [1.294-6.275]), and PLR (OR [95% CI]: 1.015 [1.010-1.022]) were independent risk factors for PHN. These three predictors were integrated to establish the prediction model and construct the nomogram. The area under the receiver operating characteristic curve (AUC) for predicting the PHN risk was 0.787, and the AUC of internal validation determined using the bootstrap method was 0.776. The DCA and calibration curve also indicated that the predictive performance of the nomogram model was commendable.

Conclusion

In this study, a risk prediction model was developed and validated to accurately forecast the probability of PHN after HZ, thereby demonstrating favorable discrimination, calibration, and clinical applicability.

Efficacy and safety of Pien Tze Huang capsules in patients with herpes zoster: A multicenter, randomized, double-blinded, and placebo-controlled trial

BACKGROUND

Herpes zoster (HZ) is a common medical condition accompanied by several distressing symptoms, including acute pain. Pien Tze Huang (PZH) is a well-known traditional Chinese medicine (TCM) with numerous pharmacological effects, including antiviral properties, neuroprotection, and immunity regulation.

PURPOSE

To investigate the efficacy and safety of PZH capsules in patients with HZ.

STUDY DESIGN

A multicenter, double-blinded, randomized, and placebo-controlled trial from 8 hospitals in 5 cities of China.

METHODS

Eligible participants were randomly assigned to the PZH capsule and placebo group at a 1:1 ratio. Treatment was conducted for 14 days with a window period of no more than 2 days. For the first 7 days, participants received antiviral drugs combined with PZH capsules (0.6 g/time, 3 times a day) or placebos. For the remaining 7 days, they were only treated with PZH capsules (0.6 g/time, 3 times a day) or placebos.

RESULTS

We included 222 patients in the full analysis set (FAS), and 187 patients in the per protocol set (PPS). The change of numeric rating scale pain scores from baseline to the seventh day (±1 day) after treatment in the PZH capsule group was statistically superior to the placebo group (FAS: 2.33 vs. 1.71, 97.5%CI: 0.03 ∼ 1.19; PPS: 2.29 vs. 1.51, 97.5%CI: 0.18 ∼ 1.38). In the PPS, there was a significant difference in the time (days) of pain relief between the placebo group and the PZH capsule group (Mean (SD): 5.71 (3.76) vs. 4.69 (3.57), p = 0.046). On the seventh day (±1 day) after treatment, the level of CD8+ cells in the PZH capsule group were higher than those of the placebo group (FAS: Mean (SD): 24.08 (6.81) vs. 21.93 (8.19), p = 0.007; PPS: Mean (SD): 24.26 (6.93) vs. 22.15 (8.51), p = 0.012). The level of cytotoxic lymphocyte cells found similar results on the seventh day (±1 day) (FAS: Mean (SD): 12.17 (4.65) vs. 10.55 (4.15), p = 0.018; PPS: Mean (SD): 12.25 (4.65) vs. 10.11 (3.93), p = 0.002). No serious adverse events were noted and PZH capsules were well tolerated.

CONCLUSION

PZH capsules confer therapeutic effects on HZ with the TCM symptom of stagnated heat of liver channel by substantially reducing the pain intensity, shortening the time of pain relief as well as regulating the immune function. On the basis of the efficacy and safety profiles, PZH capsules may be a promising complementary therapy for the treatment of HZ.

Immunogenicity in Mice Immunized with Recombinant Adenoviruses Expressing Varicella-Zoster Virus Envelope Glycoprotein E

Herpes zoster (HZ) is a disease caused by the reactivation of latent varicella-zoster virus (VZV). The subunit vaccine, Shingrix®, and live attenuated vaccine, Zostavax®, could be used as an HZ vaccine that prevents HZ from being developed due to the reactivation of latent VZV in the sensory ganglia due to aging, stress or immunosuppression. In this study, the recombinant adenoviruses rChAd63/gE expressing glycoprotein E (gE) of VZV based on chimpanzee adenovirus serotype 63 (ChAd63) were constructed and investigated for the immunogenicity of different immune pathways in C57BL/6 mice. The results showed similar CD4+ T and CD8+ T cell responses to Shingrix® were induced in mice vaccinated using rChAd63/gE via different immune pathways. This study elucidates that recombinant adenoviruses expressing VZV gE could be appropriate for further development as a new HZ vaccine candidate via different immune pathways.

Evaluation of the Immunological Efficacy of an LNP-mRNA Vaccine Prepared from Varicella Zoster Virus Glycoprotein gE with a Double-Mutated Carboxyl Terminus in Different Untranslated Regions in Mice

Cell-mediated immunity (CMI) plays a key role in the effectiveness of varicella zoster virus (VZV) vaccines, and mRNA vaccines have an innate advantage in inducing CMI. Glycoprotein E (gE) has been used widely as an antigen for VZV vaccines, and carboxyl-terminal mutations of gE are associated with VZV titer and infectivity. In addition, the untranslated regions (UTRs) of mRNA affect the stability and half-life of mRNA in the cell and are crucial for protein expression and antigenic translational efficiency. In this study, three UTRs were designed and connected to the nucleic acid sequence of gE-M, which is double mutated in the extracellular region of gE. Then, mRNA with different nucleic acids was encapsulated in lipid nanoparticles (LNPs), forming three LNP-mRNA VZV vaccines, named gE-M-Z, gE-M-M, and gE-M-P. The immune response elicited by these vaccines in mice was evaluated at intervals of 4 weeks, and the mice were sacrificed 2 weeks after the final immunization. In the results, the gE-M-P group, which retains the nucleic acid sequence of gE-M and is connected to Pfizer/BioNTech's BNT162b2 UTRs, induced the strongest humoral immune response and CMI. Because CMI is crucial for protection against VZV and for the design of VZV vaccines, this study provides a feasible strategy for improving the effectiveness and economy of future VZV vaccines.

Unmasking Acute Lymphoblastic Leukemia in a Chiropractic Patient With Musculoskeletal Complaints

A 67-year-old woman presented to a chiropractor with a four-week history of neck and low back pain, lower extremity paresthesia, profound fatigue, and cutaneous pallor. Previous cervical radiographs had revealed multilevel degenerative spondylosis. However, abnormal hematological indices, including severe thrombocytopenia and anemia, prompted concerns of an underlying hematopoietic malignancy. Interdisciplinary collaboration facilitated expedient hematological assessment, confirming acute lymphoblastic leukemia (ALL), as evidenced by lymphoblasts in a peripheral blood smear and bone marrow biopsy. Karyotyping detected a Philadelphia chromosomal mutation; the patient therefore received oral targeted tyrosine kinase inhibition coupled with serial intrathecal chemotherapy. Complete remission was achieved. However, sensorimotor symptoms persisted due to herpetic neuralgia secondary to immunosuppression. This complex case underscores the role of chiropractors as primary contact clinicians in identifying sinister pathologies underlying musculoskeletal complaints via judicious history-taking, physical evaluation, and interpretation of investigational findings. Interprofessional collaboration is pivotal in formulating an effective therapeutic strategy to improve the prognosis of patients with this disease.

Lack of strong innate immune reactivity renders macrophages alone unable to control productive Varicella-Zoster Virus infection in an isogenic human iPSC-derived neuronal co-culture model

With Varicella-Zoster Virus (VZV) being an exclusive human pathogen, human induced pluripotent stem cell (hiPSC)-derived neural cell culture models are an emerging tool to investigate VZV neuro-immune interactions. Using a compartmentalized hiPSC-derived neuronal model allowing axonal VZV infection, we previously demonstrated that paracrine interferon (IFN)-α2 signalling is required to activate a broad spectrum of interferon-stimulated genes able to counteract a productive VZV infection in hiPSC-neurons. In this new study, we now investigated whether innate immune signalling by VZV-challenged macrophages was able to orchestrate an antiviral immune response in VZV-infected hiPSC-neurons. In order to establish an isogenic hiPSC-neuron/hiPSC-macrophage co-culture model, hiPSC-macrophages were generated and characterised for phenotype, gene expression, cytokine production and phagocytic capacity. Even though immunological competence of hiPSC-macrophages was shown following stimulation with the poly(dA:dT) or treatment with IFN-α2, hiPSC-macrophages in co-culture with VZV-infected hiPSC-neurons were unable to mount an antiviral immune response capable of suppressing a productive neuronal VZV infection. Subsequently, a comprehensive RNA-Seq analysis confirmed the lack of strong immune responsiveness by hiPSC-neurons and hiPSC-macrophages upon, respectively, VZV infection or challenge. This may suggest the need of other cell types, like T-cells or other innate immune cells, to (co-)orchestrate an efficient antiviral immune response against VZV-infected neurons.

T Lymphocyte Subsets Profile and Toll-Like Receptors Responses in Patients with Herpes Zoster

Purpose

Herpes zoster (HZ) is caused by the varicella-zoster virus (VZV), and 20% of healthy humans and 50% of people with immune dysfunction have a high probability of suffering from HZ. This study aimed to screen dynamic immune signatures and explore the potential mechanism during HZ progression.

Patients and Methods

Peripheral blood samples from 31 HZ patients and 32 age-sex-matched healthy controls were collected and analyzed. The protein levels and gene levels of toll-like receptors (TLRs) were detected in peripheral blood mononuclear cells (PBMCs) by flow cytometry and quantitative real-time PCR. Further, the characteristics of T cell subsets and cytokines were detected via a cytometric bead array.

Results

Compared to healthy controls, the mRNA levels of TLR2, TLR4, TLR7, and TLR9 mRNA in PBMCs were significantly increased in HZ patients. The protein level of TLR4 and TLR7 was significantly increased in HZ patients, but the levels of TLR2 and TLR9 were dramatically decreased. The CD3+ T cells were constant in HZ and healthy controls. CD4+ T cells were decreased in HZ patients, while CD8+ T cells were increased, resulting in an improved CD4+/CD8+ T cells ratio. Further, it was found that Th2 and Th17 were not changed, but the decreased Th1 and upregulated Treg cells were found in HZ. The Th1/Th2 and Th17/Treg ratios were significantly decreased. Last, the levels of IL-6, IL-10, and IFN-γ were significantly increased, but IL-2, IL-4, and IL-17A had no significant changes.

Conclusion

The dysfunction of host's lymphocytes and activation of TLRs in PBMCs were the important mechanism in varicella-zoster virus induced herpes zoster. TLRs might be the core targets for the therapy drug development in treating HZ.

Low Trend for VZV-Associated Disease Patients to Visit Neurologists

Background

Herpes zoster (HZ) is a skin disease that can also cause virus-infectious peripheral neuropathies. Despite this, there is limited information on patient preferences for seeking medical attention for HZ and zoster-associated pain (ZAP). Our study aimed to evaluate how frequently patients with ZAP choose to visit neurologists for their symptoms.

Methods

This study conducted a retrospective review of electronic health records in three general hospitals from January 2017 to June 2022. Using association rule mining, the study analyzed referral behaviors.

Results

We identified 33,633 patients with 111,488 outpatient visits over 5.5 years. The study found that the majority of patients (74.77-91.22%) visited dermatologists during their first outpatient visit, while only a small percentage (0.86-1.47%) preferred to consult a neurologist. The proportion of patients referred to a specialist during their medical visit varied significantly between different specialties within the same hospital (p <0.05) and even within the same specialty (p<0.05). There was a weak association (Lift:1.00-1.17) of referral behaviors between dermatology and neurology. Across the three hospitals, the average number of visits to a neurologist for ZAP was 1.42-2.49, with an average electronic health record duration of 11-15 days per patient. After consulting with a neurologist, some patients were referred to other specialists.

Conclusion

It was observed that patients with HZ and ZAP tended to visit a variety of specialists, with only a small number seeking the assistance of neurologists. However, from the perspective of neuroprotection, it is the duty of neurologists to provide more means.

Acceptability of Herpes Zoster Vaccination among Patients with Diabetes: A Cross-Sectional Study in Saudi Arabia

Background: Vaccines have recently been made available free of charge by the Saudi Ministry of Health for people 50 years or older. Diabetes mellitus (DM) increases herpes zoster (HZ) susceptibility, severity, serious complications, and negative impacts on underlying DM conditions, which are highly prevalent in Saudi Arabia. This study aimed to assess the acceptability of the HZ vaccination and its predictors among patients with diabetes in the Qassim region of Saudi Arabia. Methods: A cross-sectional study of patients with diabetes from a primary healthcare center in the Qassim region was conducted. Information was obtained on sociodemographic characteristics, history of herpes zoster infection, knowing someone who had had herpes zoster, past vaccinations, and factors influencing their intention to receive the HZ vaccination through a self-administered online questionnaire. Results: The median age (IQR) was 56 years (53–62). Overall, 25% (n = 104/410) of the participants reported their acceptability of the HZ vaccination, and the predictors were being male (AOR 2.01, 95% CI 1.01–4.00, p = 0.047), believing the HZ vaccine was effective (AOR 3.94, 95% CI 2.25–6.90, p < 0.001), and awareness that immunocompromised individuals are at a higher risk of contracting HZ (AOR 2.32, 95% CI 1.37–3.93, p = 0.002). A total of 74.2% (n = 227/306) of the participants reported their acceptability of the HZ vaccination if advised by their physician, and the predictors were being male (AOR 2.37, 95% CI 1.18–4.79, p = 0.016) and having a history of varicella vaccine uptake (AOR 4.50, 95% CI 1.02–19.86, p = 0.047). Conclusions: One-quarter of the participants were ready to accept the HZ vaccine, but this proportion significantly increased when the patients were advised by their physicians. The uptake rate can be improved with the involvement of healthcare providers and focused awareness campaigns about the effectiveness of the vaccine.

Efficacy and Safety of Pulsed Radiofrequency in Herpes Zoster Related Trigeminal Neuralgia: A Systematic Review and Meta-Analysis

Purpose

Pulsed radiofrequency (PRF) is a neuromodulation technique for neuropathic pain. However, the effects of PRF on zoster-related trigeminal neuralgia (TN) remain unclear. The purpose of this meta-analysis is to investigate the efficacy and safety of PRF in the management of zoster-related TN.

Patients and Methods

We searched PubMed, Embase, Cochrane Library, Chinese Biomedical Database (CBM), Chinese National Knowledge Infrastructure (CNKI), and Wanfang for randomized controlled trials from their inception to August 2022. The primary clinical outcomes included pain intensity and adverse events. Secondary clinical outcomes included pain remission rate, trigeminal postherpetic neuralgia (TPHN) incidence, rescue analgesic dose, sleep quality, and quality of life (QoL).

Results

Eight studies with 788 participants were included for final analysis. PRF group exhibited lower pain scores (week 1: MD -2.10, 95% CI -3.28 to -0.93, P=0.0005; week 4: MD -1.56, 95% CI -2.60 to -0.51, P=0.003; week 12: MD -1.52, 95% CI -2.68 to -0.35, P=0.01), lower risk of TPHN incidence (RR 0.22, 95% CI 0.06 to 0.81, P=0.02) and better sleep quality (week 4: MD -2.52, 95% CI -3.28 to -1.77, P<0.01; week 12: MD -2.25, 95% CI -2.90 to -1.60, P<0.01) than control group. Besides, pain remission rate (RR 1.08, 95% CI 0.93 to 1.26, P=0.31) and adverse events (RR 0.95, 95% CI 0.71 to 1.27, P=0.74) were comparable in both groups.

Conclusion

PRF is an effective and safe treatment and it yields better effects in pain relief, improvement of sleep quality, and prevention of developing TPHN. Although PRF provides a comparable pain remission rate with the control, it is still a preferred and alternative treatment for relieving zoster-related facial pain.

Immune changes and their relationship with prognosis in patients with varicella-zoster virus encephalitis/meningitis

OBJECTIVES

This study aimed to investigate the immune changes in patients with varicella-zoster virus (VZV) encephalitis/meningitis and explored their relationships with prognosis.

METHODS

A total of 129 patients with herpes zoster (HZ), 32 patients with VZV encephalitis/meningitis and 31 non-HZ and non-VZV people as healthy controls were included into the present study. The numbers of peripheral T lymphocytes and the serum levels of complements 3 (C3), complements 4 (C4) and immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM) were detected and compared among groups. In 32 patients with VZV encephalitis/meningitis, the immune related variables were compared between the favorable and the unfavorable prognosis group and their relationships with prognosis were further evaluated.

RESULTS

There were marked differences in the peripheral CD3+, CD4+ and CD8+ cells and CD4+/CD8+ ratio in the three groups (P<0.05). As compared with HZ and control groups, the peripheral CD3+ and CD4+ cells were reduced dramatically in patients with VZV encephalitis/meningitis (P<0.05). In 32 patients with VZV encephalitis/meningitis, the absolute CD3+ and CD4+ cells in patients with favorable prognosis were significantly higher than in patients with unfavorable prognosis (P<0.05), and they were positively related to the prognosis of these patients (r=0.3852, P=0.0295; r=0.3719, P=0.0361).

CONCLUSION

These immune changes were compromised in VZV encephalitis/meningitis. The peripheral CD3+ and CD4+ levels may be employed to predict prognosis.

T cell immunity in HSV-1- and VZV-infected neural ganglia

Herpesviruses hijack the MHC class I (MHC I) and class II (MHC II) antigen-presentation pathways to manipulate immune recognition by T cells. First, we illustrate herpes simplex virus-1 (HSV-1) and varicella-zoster virus (VZV) MHC immune evasion strategies. Next, we describe MHC-T cell interactions in HSV-1- and VZV- infected neural ganglia. Although studies on the topic are scarce, and use different models, most reports indicate that neuronal HSV-1 infection is mainly controlled by CD8+ T cells through noncytolytic mechanisms, whereas VZV seems to be largely controlled through CD4+ T cell-specific immune responses. Autologous human stem-cell-derived in vitro models could substantially aid in elucidating these neuroimmune interactions and are fit for studies on both herpesviruses.

Selective retention of virus-specific tissue-resident T cells in healed skin after recovery from herpes zoster

Herpes zoster is a localized skin infection caused by reactivation of latent varicella-zoster virus. Tissue-resident T cells likely control skin infections. Zoster provides a unique opportunity to determine if focal reinfection of human skin boosts local or disseminated antigen-specific tissue-resident T cells. Here, we show virus-specific T cells are retained over one year in serial samples of rash site and contralateral unaffected skin of individuals recovered from zoster. Consistent with zoster resolution, viral DNA is largely undetectable on skin from day 90 and virus-specific B and T cells decline in blood. In skin, there is selective infiltration and long-term persistence of varicella-zoster virus-specific T cells in the rash site relative to the contralateral site. The skin T cell infiltrates express the canonical tissue-resident T cell markers CD69 and CD103. These findings show that zoster promotes spatially-restricted long-term retention of antigen-specific tissue-resident T cells in previously infected skin.

Activation of Interferon-Stimulated Genes following Varicella-Zoster Virus Infection in a Human iPSC-Derived Neuronal In Vitro Model Depends on Exogenous Interferon-α

Varicella-zoster virus (VZV) infection of neuronal cells and the activation of cell-intrinsic antiviral responses upon infection are still poorly understood mainly due to the scarcity of suitable human in vitro models that are available to study VZV. We developed a compartmentalized human-induced pluripotent stem cell (hiPSC)-derived neuronal culture model that allows axonal VZV infection of the neurons, thereby mimicking the natural route of infection. Using this model, we showed that hiPSC-neurons do not mount an effective interferon-mediated antiviral response following VZV infection. Indeed, in contrast to infection with Sendai virus, VZV infection of the hiPSC-neurons does not result in the upregulation of interferon-stimulated genes (ISGs) that have direct antiviral functions. Furthermore, the hiPSC-neurons do not produce interferon-α (IFNα), a major cytokine that is involved in the innate antiviral response, even upon its stimulation with strong synthetic inducers. In contrast, we showed that exogenous IFNα effectively limits VZV spread in the neuronal cell body compartment and demonstrated that ISGs are efficiently upregulated in these VZV-infected neuronal cultures that are treated with IFNα. Thus, whereas the cultured hiPSC neurons seem to be poor IFNα producers, they are good IFNα responders. This could suggest an important role for other cells such as satellite glial cells or macrophages to produce IFNα for VZV infection control.

A Guide to Preclinical Models of Zoster-Associated Pain and Postherpetic Neuralgia

Reactivation of latent varicella-zoster virus (VZV) causes herpes zoster (HZ), which is commonly accompanied by acute pain and pruritus over the time course of a zosteriform rash. Although the rash and associated pain are self-limiting, a considerable fraction of HZ cases will subsequently develop debilitating chronic pain states termed postherpetic neuralgia (PHN). How VZV causes acute pain and the mechanisms underlying the transition to PHN are far from clear. The human-specific nature of VZV has made in vivo modeling of pain following reactivation difficult to study because no single animal can reproduce reactivated VZV disease as observed in the clinic. Investigations of VZV pathogenesis following primary infection have benefited greatly from human tissues harbored in immune-deficient mice, but modeling of acute and chronic pain requires an intact nervous system with the capability of transmitting ascending and descending sensory signals. Several groups have found that subcutaneous VZV inoculation of the rat induces prolonged and measurable changes in nociceptive behavior, indicating sensitivity that partially mimics the development of mechanical allodynia and thermal hyperalgesia seen in HZ and PHN patients. Although it is not a model of reactivation, the rat is beginning to inform how VZV infection can evoke a pain response and induce long-lasting alterations to nociception. In this review, we will summarize the rat pain models from a practical perspective and discuss avenues that have opened for testing of novel treatments for both zoster-associated pain and chronic PHN conditions, which remain in critical need of effective therapies.

Comparison of the Efficacy of Short-term Peripheral Nerve Stimulation and Pulsed Radiofrequency for Treating Herpes Zoster Ophthalmicus Neuralgia

OBJECTIVE

This study aimed to investigate the effect of therapy with peripheral nerve stimulation (PNS) and pulsed radiofrequency (PRF) combined or PNS and PRF separately in patients with herpes zoster ophthalmicus (HZO).

MATERIALS AND METHODS

This cohort study included 106 cases of HZO. Three groups were identified according to the type of treatment received: combination therapy (PNS+PRF) (n=38), PRF (n=37), and PNS (n=31). The observations at 0, 1, 2, and 4 weeks; 3 and 6 months; and 1 and 2 years after the operation were analyzed. Observations at each follow-up included baseline characteristics, Numerical Rating Scale (NRS) and the Pittsburgh Sleep Quality Index (PSQI), concomitant pain medication usage, relapse rate, and adverse events.

RESULTS

The postoperative NRS of all 3 groups were significantly lower than preoperative scores. The PSQI of the 3 groups was significantly improved postoperatively, and the concomitant pain medication gradually decreased. Regarding long-term efficacy, the pain NRS and PSQI scores of the PNS+PRF and PNS groups were significantly lower than those of the PRF group ( P <0.05), and the relapse rate of the PRF group was higher than that of the PNS+PRF and PNS groups ( P <0.05). No significant difference was observed between the PNS+PRF and the PNS groups.

CONCLUSION

Both PNS and PRF treatment of HZO can decrease the pain score, yielding no serious complications. The combination of PNS and PRF or PNS alone resulted in more significant pain relief than treatment with PRF alone. Thus, PNS therapy may be a better treatment option for HZO.

Dynamic Immune Landscape and VZV-Specific T Cell Responses in Patients With Herpes Zoster and Postherpetic Neuralgia

Objectives

Varicella-zoster virus (VZV) can induce herpes zoster (HZ) and postherpetic neuralgia (PHN). Immune cells play an important role in regulating HZ and PHN pathogenesis, but the dynamic immune profiles and molecular mechanisms remain unclear. This study aimed to screen dynamic immune signatures during HZ progression and elucidate the mechanism of VZV-specific T cells in PHN.

Methods

We used cytometry by time-of-flight (CyTOF) to analyze peripheral blood mononuclear cells (PBMC) samples from 45 patients with HZ and eight age-sex-matched healthy controls, eight PHN samples and seven non-PHN samples. Correlations between the immune subsets and clinical pain-related scores were performed. Further, the characteristics of VZV-specific T cells between PHN and non-PHN patients were evaluated by VZV peptide pools stimulation. The expression level of cytokines, including granzyme B, interleukin (IL)-2, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α was performed via cytometric bead array. Finally, we analyzed the alteration of Ca²⁺ signals in dorsal root ganglion (DRG)-derived cells after TNF-α stimulation.

Results

We investigated the dynamic characteristics of the immune landscape of peripheral blood samples of patients with HZ and PHN, and depicted two major dynamic signatures in NK, CD4⁺ and CD8⁺ T subsets in patients with HZ, which closely correlated with clinical pain-related scores. The frequency of PD-1⁺CD4⁺ T cells, VZV-specific PD-1⁺CD4⁺ T cells, and the amount of TNF-α produced by VZV-specific T cells were higher in patients with PHN than without PHN. Furthermore, we showed that TNF-α could induce calcium influx in DRG-derived cells in a dose-dependent manner.

Conclusions

Our results profiled the dynamic signatures of immune cells in patients with HZ and highlighted the important role of VZV-specific T cells in the pathogenesis of PHN.

LNP-CpG ODN-adjuvanted varicella-zoster virus glycoprotein E induced comparable levels of immunity with ShingrixTM in VZV-primed mice

Latent varicella-zoster virus (VZV) may be reactivated to cause herpes zoster, which affects one in three people during their lifetime. The currently available subunit vaccine Shingrix^TM is superior to the attenuated vaccine Zostavax® in terms of both safety and efficacy, but the supply of its key adjuvant component QS21 is limited. With Ionizable lipid nanoparticles (LNPs) that were recently approved by the FDA for COVID-19 mRNA vaccines as carriers, and oligodeoxynucleotides containing CpG motifs (CpG ODNs) approved by the FDA for a subunit hepatitis B vaccine as immunostimulators, we developed a LNP vaccine encapsulating VZV-glycoprotein E (gE) and CpG ODN, and compared its immunogenicity with Shingrix^TM in C57BL/6J mice. The results showed that the LNP vaccine induced comparable levels of gE-specific IgG antibodies to Shingrix^TM as determined by enzyme-linked immunosorbent assay (ELISA). Most importantly, the LNP vaccine induced comparable levels of cell-mediated immunity (CMI) that plays decisive roles in the efficacy of zoster vaccines to Shingrix^TM in a VZV-primed mouse model that was adopted for preclinical studies of Shingrix^TM. Number of IL-2 and IFN-γ secreting splenocytes and proportion of T helper 1 (Th1) cytokine-expressing CD4⁺ T cells in LNP-CpG-adjuvanted VZV-gE vaccinated mice were similar to that of Shingrix^TM boosted mice. All of the components in this LNP vaccine can be artificially and economically synthesized in large quantities, indicating the potential of LNP-CpG-adjuvanted VZV-gE as a more cost-effective zoster vaccine.

Immunogenicity of Varicella Zoster Virus DNA Vaccines Encoding Glycoprotein E and Immediate Early Protein 63 in Mice

Herpes zoster (HZ) is caused by the reactivation of latent varicella-zoster virus (VZV) from the sensory ganglia due to aging or immunosuppression. Glycoprotein E (gE) is a widely used vaccine antigen for specific humoral and cellular immune responses. Immediate early protein 63 (IE63) is expressed during latency, suggesting that it is a potential antigen against HZ reactivation. In this study, HZ DNA vaccines encoding gE, IE63, IE63-2A-gE (where 2A is a self-cleaving sequence), or IE63-linker-gE were developed and investigated for immunogenicity in mice. The results showed that each HZ DNA vaccine induced VZV-specific antibody production. The neutralizing antibody titer elicited by IE63-2A-gE was comparable to that elicited by gE or live attenuated HZ vaccine (LAV). IE63-2A-gE-induced gE or IE63-specific INF-γ⁺ T cell frequencies in splenocytes were comparable to those of LAV. Furthermore, IE63-2A-gE, gE, or IE63 led to a significant increase in IFN-γ (IE63 stimulation) and IL-2 (gE stimulation) secretion compared to LAV, showing a Th1-biased immune response. Moreover, IE63-2A-gE and gE induced cytotoxic activity of CD8⁺ T cells compared to that of LAV. This study elucidates that the IE63-2A-gE DNA vaccine can induce both humoral and cell-mediated immune responses, which provides a candidate for the development of an HZ vaccine.

Ionizable Lipid Nanoparticles Enhanced the Synergistic Adjuvant Effect of CpG ODNs and QS21 in a Varicella Zoster Virus Glycoprotein E Subunit Vaccine

Varicella zoster virus (VZV) causes two diseases: varicella upon primary infection and herpes zoster when latent viruses in the sensory ganglia reactivate. While varicella vaccines depend on humoral immunity to prevent VZV infection, cell-mediated immunity (CMI), which plays a therapeutic role in the control or elimination of reactivated VZV in infected cells, is decisive for zoster vaccine efficacy. As one of the most abundant glycoproteins of VZV, conserved glycoprotein E (gE) is essential for viral replication and transmission between ganglion cells, thus making it an ideal target subunit vaccine antigen; gE has been successfully used in the herpes zoster vaccine ShingrixTM on the market. In this report, we found that ionizable lipid nanoparticles (LNPs) approved by the Food and Drug Administration (FDA) as vectors for coronavirus disease 2019 (COVID-19) mRNA vaccines could enhance the synergistic adjuvant effect of CpG oligodeoxynucleotides (CpG ODNs) and QS21 on VZV-gE, affecting both humoral immunity and CMI. Vaccines made with these LNPs showed promise as varicella vaccines without a potential risk of herpes zoster, which identifies them as a novel type of herpes zoster vaccine similar to ShingrixTM. All of the components in this LNP-CpG-QS21 adjuvant system were proven to be safe after mass vaccination, and the high proportion of cholesterol contained in the LNPs was helpful for limiting the cytotoxicity induced by QS21, which may lead to the development of a novel herpes zoster subunit vaccine for clinical application.

Fraternal Twins: The Enigmatic Role of the Immune System in Alphaherpesvirus Pathogenesis and Latency and Its Impacts on Vaccine Efficacy

Although the establishment, maintenance and reactivation from alphaherpesvirus latency is far from fully understood, some things are now manifestly clear: Alphaherpesvirus latency occurs in neurons of the peripheral nervous system and control of the process is multifactorial and complex. This includes components of the immune system, contributions from non-neuronal cells surrounding neurons in ganglia, specialized nucleic acids and modifications to the viral DNA to name some of the most important. Efficacious vaccines have been developed to control both acute varicella and zoster, the outcome of reactivation, but despite considerable effort vaccines for acute herpes simplex virus (HSV) infection or reactivated lesions have thus far failed to materialize despite considerable effort. Given the relevance of the immune system to establish and maintain HSV latency, a vaccine designed to tailor the HSV response to maximize the activity of components most critical for controlling reactivated infection might limit the severity of recurrences and hence reduce viral transmission. In this review, we discuss the current understanding of immunological factors that contribute to HSV and VZV latency, identify differences between varicella-zoster virus (VZV) and HSV that could explain why vaccines have been valuable at controlling VZV disease but not HSV, and finish by outlining possible strategies for developing effective HSV vaccines.

The Interplay Between Stress and Immunity Triggers Herpes Zoster Infection in COVID-19 Patients: A Review

Coronavirus disease 2019 (COVID-19) is a potential health threat in the highly mobile society of the world. Also, there are concerns regarding the co-infections occurring in COVID-19 patients. Herpes zoster (HZ) is now being reported as a co-infection in COVID-19 patients. It is a varicella-zoster virus induced viral infection affecting older people and immunocompromised individuals. Reactivation of HZ infection in COVID-19 patients are emerging and the mechanism of reactivation is still unknown. A most convincing argument would be, increased psychological and immunological stress leading to HZ in COVID-19 patients, and this review justifies this argument.

Effects of Varicella-Zoster Virus Glycoprotein E Carboxyl-Terminal Mutation on mRNA Vaccine Efficacy

Glycoprotein E (gE) is one of the most abundant glycoproteins in varicella-zoster virus and plays pivotal roles in virus replication and transmission between ganglia cells. Its extracellular domain has been successfully used as an antigen in subunit zoster vaccines. The intracellular C-terminal domain was reported to be decisive for gE trafficking between the endoplasmic reticulum, trans-Golgi network and endosomes and could influence virus spread and virus titers. Considering that the trafficking and distribution of mRNA vaccine-translated gE may be different from those of gE translated against the background of the viral genome (e.g., most gE in virus-infected cells exists as heterodimers with another glycoprotein, gI,), which may influence the immunogenicity of gE-based mRNA vaccines, we compared the humoral and cellular immunity induced by LNP-encapsulated mRNA sequences encoding the whole length of gE, the extracellular domain of gE and a C-terminal double mutant of gE (mutant Y569A with original motif AYRV, which targets gE to TGN, and mutants S593A, S595A, T596A and T598A with the original motif SSTT) that were reported to enhance virus spread and elevate virus titers. The results showed that while the humoral and cellular immunity induced by all of the mRNA vaccines was comparable to or better than that induced by the AS01B-adjuvanted subunit vaccines, the C-terminal double mutant of gE showed stable advantages in all of the indicators tested, including gE-specific IgG titers and T cell responses, and could be adopted as a candidate for both safer varicella vaccines and effective zoster vaccines.

Treatment of Elsberg Syndrome Causes Fever of Unknown Origin Attributable to Drug Reaction

A 56-year-old male with a history of non-adherence to HIV anti-retroviral therapy (ART) presented with Elsberg syndrome - varicella reactivation causing fever, painful dermatomal rash, weakness of bilateral lower extremities, and urinary and bowel dysfunction. On the third day of hospitalization, the patient developed altered mental status. An investigation for encephalitis and myelitis revealed a CD4 count of 150 cells/uL, viral load of about 150,000 copies/mL, and MRI of the lumbar spine demonstrating thickening of the cauda equina. Cerebrospinal fluid (CSF) from lumbar puncture confirmed the presence of varicella-zoster virus (VZV). Treatment with acyclovir for 21 days was initiated. However, the patient developed a persistent fever. Evaluation for the source of the fever resulted in identification of anti-viral therapy as the cause. In conclusion, the present report provides a unique example of acyclovir-induced fever developed on treatment of Elsberg syndrome.

Noncytotoxic functions of killer cell granzymes in viral infections

Cytotoxic lymphocytes produce granules armed with a set of 5 serine proteases (granzymes (Gzms)), which, together with the pore-forming protein (perforin), serve as a major defense against viral infections in humans. This granule-exocytosis pathway subsumes a well-established mechanism in which target cell death is induced upon perforin-mediated entry of Gzms and subsequent activation of various (apoptosis) pathways. In the past decade, however, a growing body of evidence demonstrated that Gzms also inhibit viral replication and potential reactivation in cell death–independent manners. For example, Gzms can induce proteolysis of viral or host cell proteins necessary for the viral entry, release, or intracellular trafficking, as well as augment pro-inflammatory antiviral cytokine response. In this review, we summarize current evidence for the noncytotoxic mechanisms and roles by which killer cells can use Gzms to combat viral infections, and we discuss the potential thereof for the development of novel therapies.

Protective role of natural killer cells in neuropathic pain conditions

ABSTRACT

During the past few years, the research of chronic neuropathic pain has focused on neuroinflammation within the central nervous system and its impact on pain chronicity. As part of the ERA-Net NEURON consortium, we aimed to identify immune cell patterns in the cerebrospinal fluid (CSF) of patients with herpes zoster neuralgia and patients with polyneuropathy (PNP), which may contribute to pain chronicity in these neuropathic pain conditions. Cerebrospinal fluid of 41 patients (10 herpes zoster and 31 PNP) was analyzed by flow cytometry identifying lymphocyte subsets: CD4+ (T-helper cells), CD8+ (cytotoxic T cells), CD19+ (B cells), and CD56+ (natural killer [NK]) cells. At baseline and at follow-up, the somatosensory phenotype was assessed with quantitative sensory testing. In addition, the patients answered epidemiological questionnaires and the PainDETECT questionnaire. Immune cell profiles and somatosensory profiles, as well as painDETECT questionnaire scores, were analyzed and correlated to determine specific immune cell patterns, which contribute to chronic pain. We found a negative correlation (P = 0.004, r = -0.596) between the frequency of NK cells and mechanical pain sensitivity (MPS), one of the most relevant quantitative sensory testing markers for central sensitization; a high frequency of NK cells correlated with low MPS. The analysis of the individual follow-up showed a worsening of the pain condition if NK-cell frequency was low. Low NK-cell frequency is associated with signs of central sensitization (MPS), whereas high NK-cell frequency might prevent central sensitization. Therefore, NK cells seem to play a protective role within the neuroinflammatory cascade and may be used as a marker for pain chronicity.

Varicella-zoster virus early infection but not complete replication is required for the induction of chronic hypersensitivity in rat models of postherpetic neuralgia

Herpes zoster, the result of varicella-zoster virus (VZV) reactivation, is frequently complicated by difficult-to-treat chronic pain states termed postherpetic neuralgia (PHN). While there are no animal models of VZV-induced pain following viral reactivation, subcutaneous VZV inoculation of the rat causes long-term nocifensive behaviors indicative of mechanical and thermal hypersensitivity. Previous studies using UV-inactivated VZV in the rat model suggest viral gene expression is required for the development of pain behaviors. However, it remains unclear if complete infection processes are needed for VZV to induce hypersensitivity in this host. To further assess how gene expression and replication contribute, we developed and characterized three replication-conditional VZV using a protein degron system to achieve drug-dependent stability of essential viral proteins. Each virus was then assessed for induction of hypersensitivity in rats under replication permissive and nonpermissive conditions. VZV with a degron fused to ORF9p, a late structural protein that is required for virion assembly, induced nocifensive behaviors under both replication permissive and nonpermissive conditions, indicating that complete VZV replication is dispensable for the induction of hypersensitivity. This conclusion was confirmed by showing that a genetic deletion recombinant VZV lacking DNA packaging protein ORF54p still induced prolonged hypersensitivities in the rat. In contrast, VZV with a degron fused to the essential IE4 or IE63 proteins, which are involved in early gene regulation of expression, induced nocifensive behaviors only under replication permissive conditions, indicating importance of early gene expression events for induction of hypersensitivity. These data establish that while early viral gene expression is required for the development of nocifensive behaviors in the rat, complete replication is dispensable. We postulate this model reflects events leading to clinical PHN, in which a population of ganglionic neurons become abortively infected with VZV during reactivation and survive, but host signaling becomes altered in order to transmit ongoing pain.

Lesson of the month: Late, disseminated herpes zoster reactivation in a stem cell transplant recipient: implications for post-transplant prophylaxis and immune monitoring

Varicella zoster reactivation is a known risk following stem-cell transplantation, but has become more infrequent since universal antiviral prophylaxis. We report an unusual case of late, disseminated reactivation in a 27-year-old man with positive pre-transplant serology, and discuss implications for post-transplant prophylaxis and immune monitoring.

Aging and Options to Halt Declining Immunity to Virus Infections

Immunosenescence is a process associated with aging that leads to dysregulation of cells of innate and adaptive immunity, which may become dysfunctional. Consequently, older adults show increased severity of viral and bacterial infections and impaired responses to vaccinations. A better understanding of the process of immunosenescence will aid the development of novel strategies to boost the immune system in older adults. In this review, we focus on major alterations of the immune system triggered by aging, and address the effect of chronic viral infections, effectiveness of vaccination of older adults and strategies to improve immune function in this vulnerable age group.

Flow cytometric analysis of T lymphocytes and cytokines in aqueous humor of patients with varicella zoster virus-mediated acute retinal necrosis

BACKGROUND

The purpose of this study is to investigate the aqueous humor (AH) T lymphocyte subsets and cytokines of acute retinal necrosis (ARN) to elucidate the immunologic inflammatory features of this disorder.

METHODS

Three patients with ARN infected with varicella zoster virus (VZV) who underwent multiple intravitreal injections of ganciclovir were enrolled in this study. The control group consisted of four non-infectious patients with acute anterior uveitis (AAU). Flow cytometric analysis was performed on the lymphocyte subsets from the AH and peripheral blood (PB) samples during the active phase of intraocular inflammation. Five inflammatory cytokines were measured in each AH sample and various clinical characteristics were also assessed.

RESULTS

VZV deoxyribonucleic acid (DNA) was detected by real-time polymerase chain reaction (PCR) in AH from all the ARN patients, who showed higher CD8+ T lymphocytes population in AH than the AAU patients (p = 0.006). CD4/CD8 ratios of T lymphocytes and the percentage of CD8 + CD25+ T lymphocytes in AH were significantly lower in ARN than in AAU (p = 0.006; p = 0.012). In the ARN patients, the percentages of CD4+ and CD8+ T lymphocytes in AH were higher than those found in PB. The percentage of CD4 + CD25+ T lymphocytes in AH was significantly higher than the proportion in PB in the AAU patients (p = 0.001). Immunoregulatory cytokine Interleukin-10 in AH was significantly elevated in the ARN patients in comparison with the case of the AAU patients (p = 0.036). In ARN, the copy number of VZV DNA in AH positively correlated with the percentage of CD8+ T lymphocytes in AH and negatively correlated with the CD4/CD8 ratio in AH during the course of disease treatment (p = 0.009, r = 0.92; p = 0.039, r = - 0.834).

CONCLUSION

The ARN patients caused by VZV had different intraocular T lymphocyte subsets and cytokines profile than those of the non-infectious patients. High percentages of CD8+ T lymphocytes and low CD4/CD8 T cell ratios may be a potential biomarker for diagnosis of viral-infectious uveitis. T lymphocytes examination at the inflammatory sites has the potential to become a useful research tool for differentiating viral and non-viral uveitis.

Immunogenicity of Varicella-Zoster Virus Glycoprotein E Formulated with Lipid Nanoparticles and Nucleic Immunostimulators in Mice

Theoretically, the subunit herpes zoster vaccine Shingrix^TM could be used as a varicella vaccine that avoids the risk of developing shingles from vaccination, but bedside mixing strategies and the limited supply of the adjuvant component QS21 have made its application economically impracticable. With lipid nanoparticles (LNPs) that were approved by the FDA as vectors for severe acute respiratory syndrome coronavirus 2 vaccines, we designed a series of vaccines efficiently encapsulated with varicella-zoster virus glycoprotein E (VZV-gE) and nucleic acids including polyinosinic-polycytidylic acid (Poly I:C) and the natural phosphodiester CpG oligodeoxynucleotide (CpG ODN), which was approved by the FDA as an immunostimulator in a hepatitis B vaccine. Preclinical trial in mice showed that these LNP vaccines could induce VZV-gE IgG titers more than 16 times those induced by an alum adjuvant, and immunized serum could block in vitro infection completely at a dilution of 1:80, which indicated potential as a varicella vaccine. The magnitude of the cell-mediated immunity induced was generally more than 10 times that induced by the alum adjuvant, indicating potential as a zoster vaccine. These results showed that immunostimulatory nucleic acids together with LNPs have promise as safe and economical varicella and zoster vaccine candidates.

Serum interleukin-10 level increases in patients with severe signs or symptoms of herpes zoster and predicts the duration of neuralgia

Herpes zoster (HZ) is caused by reactivation of latent varicella zoster virus (VZV) in the cranial nerve or dorsal root ganglia, with spread of the virus along the sensory nerve to the dermatome. Postherpetic neuralgia is a feared complication of HZ and impairs patients' quality of life enormously. However, there is no predictor of the duration of neuralgia. Our objective was to investigate whether there are correlations between the duration of neuralgia and serum levels of potential biomarkers in order to find practical predictors of the duration of neuralgia. Patients who were diagnosed with HZ at our hospital from April 2013 to January 2014 were included in this study. Serum levels of cytokines and other biomarkers were measured using commercial enzyme-linked immunosorbent assay kits. Thirty patients (15 men and 15 women) with HZ were enrolled in this study. The mean age was 66.1 ± 9.2 (standard deviation) years (range, 51-84 years). Four patients were evaluated as having mild, 19 as having moderate, and seven as having severe HZ. Patients with severe HZ suffered from neuralgia for a significantly longer period of time than patients with mild-to-moderate HZ (9.86 ± 8.25 months vs. 2.01 ± 2.68 months, severe vs. mild-to-moderate, p = 0.0021). The serum interleukin (IL)-10 level was significantly higher in patients with severe HZ than in those with mild-to-moderate HZ (12.93 ± 3.27 pg/mL vs. 6.74 ± 3.72 pg/mL; severe vs. mild-to-moderate; p = 0.0487). Furthermore, the serum IL-10 level was significantly correlated with the duration of neuralgia (r = 0.5193, p = 0.0111). Lastly, the serum IL-10 level significantly decreased after treatment in comparison with that before treatment (from 8.15 ± 4.46 pg/mL to 4.32 ± 11.83 pg/mL, p < 0.0001). In conclusion, these results suggest that the serum IL-10 level is an objective biomarker of the severity of HZ, and that the serum IL-10 level can be a practical predictor of the duration of neuralgia.

[Herpes zoster and subunit vaccine]

Varicella-zoster virus (VZV) causes varicella (chickenpox) as primary infection, and latently infects neuronal cells in the dorsal root ganglia (DRG). Reactivation of VZV from DRG results in herpes zoster, often decades later. VZV is the only airborne human herpesvirus and the only herpesvirus whose symptoms (both varicella and herpes zoster) can be prevented by vaccination. Herpes zoster is significantly more common in patients with bone marrow transplants, hematological malignancies, oral Jak inhibitors, SLE, and the elderly. The brand new subunit vaccine, ShingrixⓇ, for preventing herpes zoster is a mixture of adjuvant and recombinant VZV glycoprotein gE, which is highly effective in preventing zoster even in elderly people. In this review, the author discuss the onset mechanism of zoster from the clinical findings and summarize the result of clinical trials of the subunit vaccine.

Herpes Zoster Does Not Increase the Risk of Neurodegenerative Dementia: A Case-Control Study

OBJECTIVE

This study was conducted to evaluate the association between neurodegenerative dementia and herpes zoster infection (HZI) using a national sample cohort.

METHODS

From the national cohort study conducted by the Korean National Health Insurance Service, we extracted data for patients with neurodegenerative dementia and for 1:4 matched control participants and searched the patient histories for HZI.

RESULTS

The adjusted odds ratio (OR) for HZI was 0.90 (95% CI = 0.84-0.97) in the dementia group. According to the subgroup analysis, the adjusted OR for HZI was 0.91 (95% confidence interval [CI] = 0.83 -1.00) in the < 80 years old group, 0.88 (95% CI = 0.78 -1.00) in the ≥ 80 years old group, 0.77 (95% CI = 0.66-0.89) in men and 0.96 (95% CI = 0.88 -1.05) in women.

CONCLUSIONS

We concluded that HZI does not increase the risk of neurodegenerative dementia in individuals of any age or of either sex.

Cranial Nerve Disorders Associated With Immune Checkpoint Inhibitors

OBJECTIVE

To describe the spectrum, treatment, and outcome of cranial nerve disorders associated with immune checkpoint inhibitor (Cn-ICI).

METHODS

This nationwide retrospective cohort study on Cn-ICI (2015-2019) was conducted using the database of the French Refence Center. In addition, a systematic review of the literature (MEDLINE, Scopus, and Web of Science) for records published between 2010 and 2019 was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the search terms cranial nerve or neuropathy or palsy and immune checkpoint inhibitors.

RESULTS

Among 67 cases with ICI-related neurologic toxicities diagnosed in our reference center, 9 patients with Cn-ICI were identified (7 men, 78%, median age 62 years [range 26-82 years]). Patients were receiving a combination of anti-cytotoxic T-lymphocyte antigen 4 and anti-programmed cell death 1 (PD-1)/PD-1 ligand (n = 5, 56%) or anti-PD-1 antibodies alone (n = 4, 44%). Cn-ICI involved optic (n = 3), vestibulocochlear (n = 3), abducens (n = 2), facial (n = 2), and oculomotor (n = 1) nerves. Two patients had involvement of 2 different cranial nerves. Treatment comprised corticosteroids (n = 8, 89%), ICI permanent discontinuation (n = 7, 78%), plasma exchange (n = 2, 22%), and IV immunoglobulin (n = 1, 11%). Median follow-up was 11 months (range 1-41 months). In 3 cases (33%), neurologic deficit persisted/worsened despite treatment: 2 optic and 1 vestibulocochlear. Among cases from the literature and the present series combined (n = 39), the most commonly affected cranial nerves were facial (n = 13, 33%), vestibulocochlear (n = 8, 21%), optic (n = 7, 18%), and abducens (n = 4, 10%). Trigeminal, oculomotor, and glossopharyngeal nerves were less frequently affected (total n = 7).

CONCLUSION

Cranial nerve disorders can complicate treatment with ICIs. Approximately one-third of the patients had persisting deficits, most frequently involving hearing and vision loss.

Insights into the pathogenesis of varicella viruses

Purpose of review

Varicella zoster virus (VZV) is a highly contagious, neurotropic alpha herpes virus that causes varicella (chickenpox). VZV establishes lifelong latency in the sensory ganglia from which it can reactivate to induce herpes zoster (HZ), a painful disease that primarily affects older individuals and those who are immune-suppressed. Given that VZV infection is highly specific to humans, developing a reliable in vivo model that recapitulates the hallmarks of VZV infection has been challenging. Simian Varicella Virus (SVV) infection in nonhuman primates reproduces the cardinal features of VZV infections in humans and allows the study of varicella virus pathogenesis in the natural host. In this review, we summarize our current knowledge about genomic and virion structure of varicelloviruses as well as viral pathogenesis and antiviral immune responses during acute infection, latency and reactivation. We also examine the immune evasion mechanisms developed by varicelloviruses to escape the host immune responses and the current vaccines available for protecting individuals against chickenpox and herpes zoster.

Recent findings

Data from recent studies suggest that infected T cells are important for viral dissemination to the cutaneous sites of infection as well as site of latency and that a viral latency-associated transcript might play a role in the transition from lytic infection to latency and then reactivation.

Summary

Recent studies have provided exciting insights into mechanisms of varicelloviruses pathogenesis such as the critical role of T cells in VZV/SVV dissemination from the respiratory mucosa to the skin and the sensory ganglia; the ability of VZV/SVV to interfere with host defense; and the identification of VLT transcripts in latently infected ganglia. However, our understanding of these phenomena remains poorly understood. Therefore, it is critical that we continue to investigate host-pathogen interactions during varicelloviruses infection. These studies will lead to a deeper understanding of VZV biology as well as novel aspects of cell biology.

Immune Responses to Varicella-Zoster Virus Glycoprotein E Formulated with Poly(Lactic-co-Glycolic Acid) Nanoparticles and Nucleic Acid Adjuvants in Mice

The subunit herpes zoster vaccine Shingrix is superior to attenuated vaccine Zostavax in both safety and efficacy, yet its unlyophilizable liposome delivery system and the limited supply of naturally sourced immunological adjuvant QS-21 still need to be improved. Based on poly(lactic-co-glycolic acid) (PLGA) delivery systems that are stable during the lyophilization and rehydration process and using a double-emulsion (w/o/w) solvent evaporation method, we designed a series of nanoparticles with varicella-zoster virus antigen glycoprotein E (VZV-gE) as an antigen and nucleic acids including polyinosinic-polycytidylic acid (Poly I:C) and phosphodiester CpG oligodeoxynucleotide (CpG ODN), encapsulated as immune stimulators. While cationic lipids (DOTAP) have more potential than neutral lipids (DOPC) for activating gE-specific cell-mediated immunity (CMI) in immunized mice, especially when gE is encapsulated in and presented on the surface of nanoparticles, PLGA particles without lipids have the greatest potential to induce not only the highest gE-specific IgG titers but also the strongest gE-specific CMI responses, including the highest proportions of interferon-γ (IFN-γ)- and interleukin-2 (IL-2)-producing CD4+/CD8+ T cells according to a flow cytometry assay and the greatest numbers of IFN-γ- and IL-2-producing splenocytes according to an enzyme-linked immunospot (ELISPOT) assay. These results showed that immune-stimulating nucleic acids together with the PLGA delivery system showed promise as a safe and economical varicella and zoster vaccine candidate.

Zoster Vaccination in Older Adults: Efficacy and Public Health Implications

Shingles and its most common disabling complication, post-herpetic neuralgia, represent a serious public health challenge in the older population. The decline in the T-cell-mediated immune response to varicella zoster virus after age 50 is clearly associated with increased risk of viral reactivation, causing an acutely painful zoster rash, which may have a severe prodrome of dermatomal pain and persist as seriously debilitating post-herpetic neuralgia well beyond the resolution of the rash. However, new vaccines and adjuvants are being developed and trialed and are now more effective in preventing shingles and the sequelae of post-herpetic neuralgia. Those vaccines that possess the ability to enhance antigen presentation and reverse memory T-cell exhaustion, as well as diminish the immune suppressive effects of regulatory T cells, are most likely to be effective in older adults.

Zoster patients on earth and astronauts in space share similar immunologic profiles

BACKGROUND

On long-duration spaceflight, most astronauts experience persistent immune dysregulation and the reactivation of latent herpesviruses, including varicella zoster virus (VZV). To understand the clinical risk of these perturbations to astronauts, we paralleled the immunology and virology work-up of astronauts to otherwise healthy terrestrial persons with acute herpes zoster.

METHODS

Blood samples from 42 zoster patients - confirmed positive by PCR for VZV DNA in saliva (range from 100 to >285 million copies/mL) were analyzed for peripheral leukocyte distribution, T cell function, and plasma cytokine profiles via multi-parametric flow cytometry and multiplex bead-based immune-array assays. Patient findings were compared to normal value ranges specific for each assay that were defined in-house previously from healthy adult test subjects.

RESULTS

Compared to the healthy adult ranges, the zoster patients possess (1) a higher proportion of constitutively activated T-cells, (2) a T-cell population skewed towards a more experienced maturation state, (3) depressed general T-cell function, and (4) a higher concentration of 20 of 22 measured plasma cytokines.

DISCUSSION

The pattern of immune dysregulation in zoster patients is similar to that of astronauts during spaceflight who shed VZV DNA in their saliva. Because future deep space exploration missions will be of an unprecedented duration, prolonged immune depression and chronic viral reactivation threaten to manifest overt disease in exploration class astronauts.

Tofacitinib modulates the VZV-specific CD4+ T cell immune response in vitro in lymphocytes of patients with rheumatoid arthritis

OBJECTIVE

RA is a chronic inflammatory disease characterized by lymphocyte infiltration and release of inflammatory cytokines. Previous studies have shown that treatment with Janus kinase inhibitors, such as tofacitinib, increased the incidence rate of herpes zoster compared with conventional DMARDs. Therefore, this study aimed to investigate the effect of tofacitinib on the varicella-zoster-virus (VZV)-specific T cell immune response.

METHODS

The effect of tofacitinib on the VZV-specific T cell immune response was determined by evaluating the IFNγ production, the proliferative capacity, the VZV-induced differentiation into effector and memory T cells, the expression of activation marker CD69 and helper T cell type 1 (Th1)-characteristic chemokine receptors, such as CXCR3 and CCR5, as well as cytotoxic activity (perforin and granzyme B expression) of CD4+ T cells of patients with RA compared with healthy donors upon stimulation with VZV antigen in vitro.

RESULTS

Tofacitinib significantly reduced the IFNγ production, proliferation, activation, and CXCR3 expression of VZV-specific CD4+ T cells in a dose-dependent manner in short- and long-term lymphocyte culture. No effect on the distribution of naive, effectors or memory, or on the expression of perforin or granzyme B by VZV-specific CD4+ T cells was observed.

CONCLUSION

This study showed that tofacitinib significantly modulated the Th1 response to VZV. The poor VZV-specific cellular immune response in patients with RA may be considered in recommendations regarding appropriate vaccination strategies for enhancing the VZV-specific Th1 response.

Manipulation of the Innate Immune Response by Varicella Zoster Virus

Varicella zoster virus (VZV) is the causative agent of chickenpox (varicella) and shingles (herpes zoster). VZV and other members of the herpesvirus family are distinguished by their ability to establish a latent infection, with the potential to reactivate and spread virus to other susceptible individuals. This lifelong relationship continually subjects VZV to the host immune system and as such VZV has evolved a plethora of strategies to evade and manipulate the immune response. This review will focus on our current understanding of the innate anti-viral control mechanisms faced by VZV. We will also discuss the diverse array of strategies employed by VZV to regulate these innate immune responses and highlight new knowledge on the interactions between VZV and human innate immune cells.

Granzyme B Cleaves Multiple Herpes Simplex Virus 1 and Varicella-Zoster Virus (VZV) Gene Products, and VZV ORF4 Inhibits Natural Killer Cell Cytotoxicity

Immune regulation of alphaherpesvirus latency and reactivation is critical for the control of virus pathogenesis. This is evident for herpes simplex virus 1 (HSV-1), where cytotoxic T lymphocytes (CTLs) prevent viral reactivation independent of apoptosis induction. This inhibition of HSV-1 reactivation has been attributed to granzyme B cleavage of HSV infected cell protein 4 (ICP4); however, it is unknown whether granzyme B cleavage of ICP4 can directly protect cells from CTL cytotoxicity. Varicella zoster virus (VZV) is closely related to HSV-1; however, it is unknown whether VZV proteins contain granzyme B cleavage sites. Natural killer (NK) cells play a central role in VZV and HSV-1 pathogenesis and, like CTLs, utilize granzyme B to kill virally infected target cells. However, whether alphaherpesvirus granzyme B cleavage sites could modulate NK cell-mediated cytotoxicity has yet to be established. This study aimed to identify novel HSV-1 and VZV gene products with granzyme B cleavage sites and assess whether they could protect cells from NK cell-mediated cytotoxicity. We have demonstrated that HSV ICP27, VZV open reading frame 62 (ORF62), and VZV ORF4 are cleaved by granzyme B. However, in an NK cell cytotoxicity assay, only VZV ORF4 conferred protection from NK cell-mediated cytotoxicity. The granzyme B cleavage site in ORF4 was identified via site-directed mutagenesis and, surprisingly, the mutation of this cleavage site did not alter the ability of ORF4 to modulate NK cell cytotoxicity, suggesting that ORF4 has a novel immunoevasive function that is independent from the granzyme B cleavage site.IMPORTANCE HSV-1 causes oral and genital herpes and establishes life-long latency in sensory ganglia. HSV-1 reactivates multiple times in a person's life and can cause life-threatening disease in immunocompromised patients. VZV is closely related to HSV-1, causes chickenpox during primary infection, and establishes life-long latency in ganglia, from where it can reactivate to cause herpes zoster (shingles). Unlike HSV-1, VZV only infects humans, and there are limited model systems; thus, little is known concerning how VZV maintains latency and why VZV reactivates. Through studying the link between immune cell cytotoxic functions, granzyme B, and viral gene products, an increased understanding of viral pathogenesis will be achieved.

Herpes Zoster Vaccines

Background

Immunization for herpes zoster (HZ) aims to reverse the decline in cell-mediated immunity to varicella zoster virus that occurs with advancing age or immunocompromise. There are 2 vaccines available, one live attenuated (Zoster vaccine, live attenuated [ZVL]) and, recently, a recombinant subunit vaccine (HZ/su).

Methods

The literature relevant to the two HZ vaccines was reviewed.

Results

ZVL has overall efficacies of 51% and 65% against HZ and postherpetic neuralgia, respectively, with a prominent decline in efficacy with advancing age of the vaccinee. This compares to approximately 90% efficacy against HZ for HZ/su that is minimally affected with advancing age. The efficacy of ZVL against HZ declines over 4 and 8 years, compared with minimal decline so far over 4 years with HZ/su, and immunogenicity that is maintained for 9 years. Local and systemic reactogenicity to HZ/su is much greater than to ZVL.

Conclusions

HZ/su establishes an important principle-that a single recombinant viral protein with an effective adjuvant combination can stimulate immunogenicity superior to that of a live attenuated vaccine, and that this can diminish immunosenescence. This provides hope for improvement of other vaccines for aging patients. However, key questions remain unanswered, including the durability of the efficacy of HZ/su, its efficacy as a booster for previous recipients of ZVL, and its efficacy in immunocompromised patients.

Persistence of a T Cell Infiltrate in Human Ganglia Years After Herpes Zoster and During Post-herpetic Neuralgia

Varicella-zoster virus (VZV) is a human herpesvirus which causes varicella (chicken pox) during primary infection, establishes latency in sensory ganglia, and can reactivate from this site to cause herpes zoster (HZ) (shingles). A major complication of HZ is a severe and often debilitating pain called post-herpetic neuralgia (PHN) which persists long after the resolution of the HZ-associated rash. The underlying cause of PHN is not known, although it has been postulated that it may be a consequence of immune cell mediated damage. However, the nature of virus-immune cell interactions within ganglia during PHN is unknown. We obtained rare formalin fixed paraffin embedded sections cut from surgically excised ganglia from a PHN-affected patient years following HZ rash resolution. VZV DNA was readily detected by qPCR and regions of immune infiltration were detected by hematoxylin and eosin staining. Immunostaining using a range of antibodies against immune cell subsets revealed an immune cell response comprising of CD4⁺ and CD8⁺ T cells and CD20⁺ B cells. This study explores the immune cell repertoire present in ganglia during PHN and provides evidence for an ongoing immune cell inflammation years after HZ.

Varicella zoster virus vaccines: an update

Varicella zoster virus (VZV) is the etiological agent of varicella, a highly infectious, self-limiting disease with serious complications. The decline in cell-mediated immunity (CMI) that occurs with aging or immunodepression causes a reactivation of the latent VZV as herpes zoster (HZ). Prevention of VZV through varicella vaccination strategies allows to avoid the primary infection in newborns and susceptible subjects. Available monovalent and combined VZV vaccines are effective, safe and generally well tolerated. Universal varicella vaccination has significantly impacted on incidence, complications and deaths related to this disease. Prevention of HZ through vaccination is a priority to avoid the significant burden of its incidence and complications. Currently two HZ vaccines are available. The recombinant zoster vaccine (RZV), approved by the FDA in 2017 and Zoster Vaccine Live (ZVL) licensed in the United States by the FDA in 2006. The advisory committee on immunization practices (ACIP) preferentially recommends RZV. ZVL remains an option for prevention of HZ in immunocompetent adults aged ≥60 years, although the CMI tends to wane a few years after vaccination.