Immuno-metabolic changes in herpes virus infection

Cerebrospinal fluid proteomics in meningitis patients with reactivated varicella zoster virus

OBJECTIVE

This study investigated the proteomic characteristics of cerebrospinal fluid (CSF) in patients with varicella zoster virus (VZV) meningitis to understanding the pathogenesis of central nervous system (CNS) infection by reactivated VZV.

METHOD

We used data-independent acquisition model to analyze the CSF proteomic differences of 28 patients with VZV meningitis and 11 herpes zoster (HZ) patients. According to the clinical manifestations at discharge, 28 VZV meningitis patients were divided into favorable outcome group and unfavorable outcome (UO) group and their differences in CSF proteome were also analyzed.

RESULTS

Compared with the HZ group, the proteins (CXCL10, ELANE, IL-1RN, MPO, PRTN3, etc.) related to inflammation and immune cell activation were significantly upregulated in the VZV meningitis group (p < .01). The protein related to the nerve function and energy metabolism (CKMT1B, SLITRK3, Synaptotagmin-3, KIF5B, etc.) were significantly downregulated (p < .05). The levels of a pro-inflammatory factor, IL-18, in CSF were significantly higher in patients in the UO group as compared to patients with favorable prognosis (p < .05).

CONCLUSION

Inflammatory immune response is an important pathophysiological mechanism of CNS infection by VZV, and the CSF IL-18 levels might be a potential prognostic indicator of the outcomes of VZV meningitis.

Analysis of temporal metabolic rewiring for human respiratory syncytial virus infection by integrating metabolomics and proteomics

INTRODUCTION

Human respiratory syncytial virus (HRSV) infection causes significant morbidity, and no effective treatments are currently available. Viral infections induce substantial metabolic changes in the infected cells to optimize viral production. Metabolites that reflect the interactions between host cells and viruses provided an opportunity to identify the pathways underlying severe infections.

OBJECTIVE

To better understand the metabolic changes caused by HRSV infection, we analyzed temporal metabolic profiling to provide novel targets for therapeutic strategies for inhaled HRSV infection.

METHODS

The epithelial cells and BALB/c mice were infected with HRSV. Protein and mRNA levels of inflammation factors were measured by using quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Untargeted metabolomics, lipidomics and proteomics were performed using liquid chromatography coupled with mass spectrometry to profile the metabolic phenotypic alterations in HRSV infection.

RESULTS

In this study, we evaluated the inflammatory responses in vivo and in vitro and investigated the temporal metabolic rewiring of HRSV infection in epithelial cells. We combined metabolomics and proteomic analyses to demonstrate that the redox imbalance was further provoked by increasing glycolysis and anaplerotic reactions. These responses created an oxidant-rich microenvironment that elevated reactive oxygen species levels and exacerbated glutathione consumption.

CONCLUSION

These observations indicate that adjusting for metabolic events during a viral infection could represent a valuable approach for reshaping the outcome of infections.

Using CSF Proteomics to Investigate Herpesvirus Infections of the Central Nervous System

Herpesviruses have complex mechanisms enabling infection of the human CNS and evasion of the immune system, allowing for indefinite latency in the host. Herpesvirus infections can cause severe complications of the central nervous system (CNS). Here, we provide a novel characterization of cerebrospinal fluid (CSF) proteomes from patients with meningitis or encephalitis caused by human herpes simplex virus 1 (HSV-1), which is the most prevalent human herpesvirus associated with the most severe morbidity. The CSF proteome was compared with those from patients with meningitis or encephalitis due to human herpes simplex virus 2 (HSV-2) or varicella-zoster virus (VZV, also known as human herpesvirus 3) infections. Virus-specific differences in CSF proteomes, most notably elevated 14-3-3 family proteins and calprotectin (i.e., S100-A8 and S100-A9), were observed in HSV-1 compared to HSV-2 and VZV samples, while metabolic pathways related to cellular and small molecule metabolism were downregulated in HSV-1 infection. Our analyses show the feasibility of developing CNS proteomic signatures of the host response in alpha herpes infections, which is paramount for targeted studies investigating the pathophysiology driving virus-associated neurological disorders, developing biomarkers of morbidity, and generating personalized therapeutic strategies.

Th1 regulatory events by infectious pathogens, herpes zoster and herpes simplex viruses: prospects for therapeutic options for atopic eczema

Infections caused by viral and bacterial pathogens are typically perceived as harmful, such as in cases of herpes zoster and herpes simplex virus infections. However, clinical observation of an improvement in atopic skin lesions upon herpes virus infection has been noted, particularly at the site of varicella and Kaposi’s varicelliform eruption. Th1 immune cells and cytokines, mobilized and induced for protection against infectious pathogens, are expected to improve Th2 dominant atopic symptoms. This study focuses on Th1 immunoregulatory events mediated by infectious pathogens, particularly herpes viruses. Immunoregulatory events induced by herpes viruses may have a potential therapeutic value for treating atopic eczema.

An extract of Stephania hernandifolia, an ethnomedicinal plant, inhibits herpes simplex virus 1 entry

Stephania hernandifolia (Nimukho), an ethnomedicinal herb from rural Bengal, has been used traditionally for the management of nerve, skin, urinary, and digestive ailments. Here, we attempted to confirm the antiviral potential of aqueous, methanol, and chloroform extracts of S. hernandifolia against herpes simplex virus type 1 (HSV-1), the causative agent of orolabial herpes in humans, and decipher its underlying mechanism of action. The bioactive extract was standardized and characterized by gas chromatography-mass spectroscopy, while cytotoxicity and antiviral activity were evaluated by MTT and plaque reduction assay, respectively. Two HSV strains, HSV-1F and the clinical isolate VU-09, were inhibited by the chloroform extract (CE) with a median effective concentration (EC₅₀) of 4.32 and 4.50 µg/ml respectively, with a selectivity index (SI) of 11. Time-of-addition assays showed that pre-treatment of virus-infected cells with the CE and its removal before infection reduced the number of plaques without lasting toxicity to the cell, indicating that the CE affected the early stage in the viral life cycle. The number of plaques was also reduced by direct inactivation of virions and by the addition of CE for a short time following attachment of virions. These results together suggest that modification of either the virion surface or the cell surface by the CE inhibits virus entry into the host cell.

An immune epigenetic insight to COVID-19 infection

Severe acute respiratory syndrome coronavirus-2 is a positive-sense RNA virus, a causal agent of ongoing COVID-19 pandemic. ACE2R methylation across three CpG sites (cg04013915, cg08559914, cg03536816) determines the host cell's entry. It regulates ACE2 expression by controlling the SIRT1 and KDM5B activity. Further, it regulates Type I and III IFN response by modulating H3K27me3 and H3K4me3 histone mark. SARS-CoV-2 protein with bromodomain and protein E mimics bromodomain histones and evades from host immune response. The 2'-O MTases mimics the host's cap1 structure and plays a vital role in immune evasion through Hsp90-mediated epigenetic process to hijack the infected cells. Although the current review highlighted the critical epigenetic events associated with SARS-CoV-2 immune evasion, the detailed mechanism is yet to be elucidated.

Brain-derived neurotrophic factor is down regulated after bovine alpha-herpesvirus 5 infection in both wild-type and TLR3/7/9 deficient mice

Neurotrophic factors have been implicated in the control of neuronal survival and plasticity in different brain diseases. Meningoencephalitis caused by bovine alpha-herpesvirus 5 (BoHV-5) infection is a frequent neurological disease of young cattle, being the involvement of apoptosis in the development of neuropathological changes frequently discussed in the literature. It's well known that Toll-like receptors (TLRs) can activate neuroinflammatory response and consequently lead to neuronal loss. However, there are no studies evaluating the expression of neurotrophic factors and their association with brain pathology and TLRs during the infection by BoHV-5. The current study aimed to analyze brain levels of neurotrophic factors along with neuropathological changes during acute infection by BoHV-5 in wild-type (WT) and TLR3/7/9 (TLR3/7/9-/-) deficiency mice. The infection was induced by intracranial inoculation of 1 × 104 TCID50 of BoHV-5. Infected animals presented similar degrees of clinical signs and neuropathological changes. Both infected groups had meningoencephalitis and neuronal damage in CA regions from hippocampus. BoHV-5 infection promoted the proliferation of Iba-1 positive cells throughout the neuropil, mainly located in the frontal cortex. Moreover, significant lower levels of brain-derived neurotrophic factor (BDNF) were detected in both BoHV-5 infected WT and TLR3/7/9 deficient mice, compared with non-infected animals. Our study showed that BDNF down regulation was associated with brain inflammation, reactive microgliosis and neuronal loss after bovine alpha-herpesvirus 5 infection in mice. Moreover, we demonstrated that combined TLR3/7/9 deficiency does not alter those parameters.

Global Gene Expression Analysis of the Brainstem in EV71- and CVA16-Infected Gerbils

Enterovirus 71 (EV71) and coxsackievirus A16 (CVA16) are the two most important pathogens of hand, foot, and mouth disease (HFMD). However, the neuropathogenesis of EV71 and CVA16 has not been elucidated. In our previous study, we established gerbils as a useful model for both EV71 and CVA16 infection. In this work, we used RNA-seq technology to analyze the global gene expression of the brainstem of EV71- and CVA16-infected gerbils. We found that 3434 genes were upregulated while 916 genes were downregulated in EV71-infected gerbils. In CVA16-infected gerbils, 1039 genes were upregulated, and 299 genes were downregulated. We also found significant dysregulation of cytokines, such as IP-10 and CXCL9, in the brainstem of gerbils. The expression levels of 10 of the most upregulated genes were confirmed by real-time RT-PCR, and the upregulated tendency of most genes was in accordance with the differential gene expression (DGE) results. Our work provided global gene expression analysis of virus-infected gerbils and laid a solid foundation for elucidating the neuropathogenesis mechanisms of EV71 and CVA16.

Marine Algae: A Potential Resource of Anti-HSV Molecules

Herpes simplex viruses (HSVs) are common human pathogens belonging to the subfamily alpha-herpesvirinae that trigger severe infections in neonates and immunocompromised patients. After primary infection, the HSVs establish a lifelong latent infection in the vegetative neural ganglia of their hosts. HSV infections contribute to substantial disease burden in humans as well as in newborns. Despite a fair number of drugs being available for the treatment of HSV infections, new, effective, and safe antiviral agents, exerting different mechanisms of action, are urgently required, mainly due to the increasing number of resistant strains. Accumulating pieces of evidence have suggested that structurally diverse compounds from marine algae possess promising anti-HSV potentials. Several studies have documented a variety of algal polysaccharides possessing anti-HSV activity, including carrageenan and fucan. This review aimed to compile previous anti-HSV studies on marine algae–derived compounds, especially sulfated polysaccharides, along with their mode of action, toward their development as novel natural anti-HSV agents for future investigations.