Enhanced expression of cytokines/chemokines in cerebrospinal fluids in mumps meningitis in children

Insertion of a short non-viral sequence in the 3' noncoding region of the hemagglutinin-neuraminidase increases mumps virus neurovirulence

The mumps virus is a promising candidate as a vaccine vector or oncolytic therapy agent. However, its neurotropic nature, driven by molecular mechanisms that remain unclear, poses a significant obstacle to its development for these applications. This study utilizes recombinant mumps virus carrying the enhanced green fluorescent protein gene (EGFP) and two additional viruses containing, alongside EGFP, unique non-viral, non-coding 84-nucleotide inserts in the 3' non-coding region (NCR) of the hemagglutinin-neuraminidase (HN) gene. We observed a significant increase in neurovirulence for both viruses containing inserts in the 3' NCR of HN. The insert in HN 3' NCR provided a replicative advantage in the brains of newborn rats and rat brain-derived cell cultures. While the viruses were able to infect rat neurons, infection of astrocytes was completely inhibited. Additionally, in infected rat brain and rat brain-derived cell cultures we detected induction of RANTES. We observed no correlation in the extent of neuronal apoptosis or the induction of pro-inflammatory cytokines between viruses with or without the HN 3' NCR insert.

Clinical efficacy evaluation and potential mechanism prediction on Pudilan Xiaoyan oral liquid in treatment of mumps in children based on meta-analysis, network pharmacology, and molecular docking

Background: Mumps is caused by the mumps virus and is characterized by pain and parotid gland swelling. Although its incidence has declined due to vaccines, outbreaks still occur among children. In addition, it can lead to severe complications, so it has a certain perniciousness. Pudilan Xiaoyan oral liquid (PDL), a Chinese patent medicine, commonly treats children with mumps. However, its safety, efficacy, and specific mechanisms lack relevant evaluation and analysis. Therefore, we did a meta-analysis of the randomized controlled trials combined with a network pharmacology analysis to assess the efficacy and safety of PDL in relieving symptoms of mumps in children and investigate its pharmacological mechanisms. Methods: This study systematically searched the China National Knowledge Infrastructure (CNKI), WanFang Data Knowledge Service Platform, VIP Database, Sinomed, Chinese Medical Journal Full-text Database, PubMed, Embase, Cochrane Library, Web of Science, and Google Scholar for the published randomized controlled trials (date up to 3 March 2022; studies in both English and Chinese) comparing PDL and antiviral drug combination treatment to standalone antiviral drug treatment. The primary outcomes in this study were the effective rate and duration of five characteristic symptoms of children's mumps. We assessed the pooled data by using a fix-effect or random-effect model. We illustrated an odds ratio (OR) or standardized mean difference (SMD) with a 95% confidence interval (CI) using the Stata 15 software. In network pharmacology, active components of PDL were collected from the traditional Chinese medicine system pharmacology technology platform and the CNKI studies, while mumps' targets were collected from databases of the Genecards and Online Mendelian Inheritance in Man (OMIM), and then we constructed a "drug-component-target" network and a protein-protein interaction network using Cytoscape 3.9.0 for screening the core components and targets. Next, we ran Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of intersection targets of PDL and mumps. Finally, molecular docking was performed between core components and targets. Results: Of 70 identified studies, 12 were eligible and included in our analysis (N = 1,307 participants). Compared with the antiviral drug treatments, combination treatment using PDL and antiviral drugs provided higher effective rates (OR = 5.94), shorter symptom durations for fever (SMD = -1.05), headache (SMD = -0.69), parotid gland swelling (SMD = -1.30), parotid gland pain (SMD = -2.53), and loss of appetite (SMD = -0.56) with fewer reported side effects. Of the 113 active components of PDL and 57 mumps' targets, 11 core components like quercetin, isoetin, and seven core targets such as albumin (ALB) and interleukin-6 were obtained. Moreover, the potential pathways identified included cytokine-cytokine receptor interaction and T helper cell 17 (Th17 cell) differentiation. Molecular docking results revealed that most core components and targets could form stable structures. The core components, including isoetin, quercetin, and luteolin, and core targets involving heat shock protein HSP 90-alpha (HSP90AA1), estrogen receptor (ESR1), and ALB showed the best affinities. Conclusion: The combined use of PDL and antiviral drugs could effectively improve the efficacy of mumps among children and rapidly alleviate mumps-related symptoms. This efficacy may be associated with the anti-inflammatory and antiviral mechanisms by which PDL acts using multiple components, multiple targets, and multiple pathways. However, these results should be confirmed by further studies.

Neuroinflammation and Its Impact on the Pathogenesis of COVID-19

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The clinical manifestations of COVID-19 include dry cough, difficult breathing, fever, fatigue, and may lead to pneumonia and respiratory failure. There are significant gaps in the current understanding of whether SARS-CoV-2 attacks the CNS directly or through activation of the peripheral immune system and immune cell infiltration. Although the modality of neurological impairments associated with COVID-19 has not been thoroughly investigated, the latest studies have observed that SARS-CoV-2 induces neuroinflammation and may have severe long-term consequences. Here we review the literature on possible cellular and molecular mechanisms of SARS-CoV-2 induced-neuroinflammation. Activation of the innate immune system is associated with increased cytokine levels, chemokines, and free radicals in the SARS-CoV-2-induced pathogenic response at the blood-brain barrier (BBB). BBB disruption allows immune/inflammatory cell infiltration into the CNS activating immune resident cells (such as microglia and astrocytes). This review highlights the molecular and cellular mechanisms involved in COVID-19-induced neuroinflammation, which may lead to neuronal death. A better understanding of these mechanisms will help gain substantial knowledge about the potential role of SARS-CoV-2 in neurological changes and plan possible therapeutic intervention strategies.

Interleukin-6-Mediated Inflammation May Cause Methotrexate-Induced Leukoencephalopathy

Children with leukemia treated with methotrexate (MTX) may develop MTX-induced leukoencephalopathy, which can present as seizures or focal neurological deficits. However, the precise pathophysiology has not been fully elucidated. Differences in cytokine/chemokine profiles in cerebrospinal fluid (CSF) between children with MTX-induced leukoencephalopathy and those with posterior reversible encephalopathy syndrome (PRES), an acute neurological condition associated with hypertension, were investigated. Interleukin (IL)-1β, 2, 4, 5, 6, 7, 8, 10, 12, 13, and 17, tumor necrosis factor-alpha, interferon-gamma, granulocyte monocyte colony-stimulating factor, granulocyte colony-stimulating factor, macrophage inflammatory protein-1β, and monocyte chemoattractant protein-1 concentrations were measured in CSF supernatants from 3 children with acute leukemia with MTX-induced leukoencephalopathy, 3 children with acute leukemia with PRES, 6 children with acute leukemia without neurological complications, and 8 children with acute encephalopathy. CSF IL-6 concentrations were higher in children with MTX-induced leukoencephalopathy than in children with acute leukemia with PRES, with acute leukemia without neurological complications, and with acute encephalopathy. We concluded that IL-6 may be involved in the pathogenesis of MTX-induced leukoencephalopathy.

High neopterin and IP-10 levels in cerebrospinal fluid are associated with neurotoxic tryptophan metabolites in acute central nervous system infections

Background

The host response to intruders in the central nervous system (CNS) may be beneficial but could also be harmful and responsible for neurologic symptoms and sequelae in CNS infections. This immune response induces the activation of the kynurenine pathway (KP) with the production of neuroactive metabolites. Herein, we explored cytokine and KP responses in cerebrospinal fluid (CSF) and serum in patients with encephalitis, aseptic, and bacterial meningitis.

Methods

Cytokines were measured in CSF and serum by multiplex assay in adult patients with encephalitis of infectious, autoimmune or unknown etiology (n = 10), aseptic meningitis (ASM, n = 25), acute bacterial meningitis (ABM, n = 6), and disease control patients with similar symptoms but without pleocytosis in CSF (n = 42). Liquid chromatography-tandem mass spectrometry (LC-MS/ MS) was used to measure KP metabolites in CSF and serum.

Results

A characteristic pattern of increasing cytokine levels and KP metabolites was found in CSF from encephalitis to ASM, with the highest levels in ABM. In ASM and ABM, most inflammatory mediators, including IL-6, IL-8, and IFN-inducible protein-10 (IP-10), showed markedly elevated levels in CSF compared with serum, indicating production within the CNS. In contrast to most mediators, the highest level of IP-10 was found in the ASM group, suggesting a potential role for IP-10 in aseptic/viral meningitis. Neopterin and IP-10 were associated with marked changes in KP metabolites in CSF with increasing kynurenine/tryptophan ratio reflecting indoleamine 2,3-dioxygenase activity. Neopterin, a marker of IFN-γ activity, was associated with an unfavorable balance between neuroprotective and neurotoxic tryptophan metabolites.

Conclusion

We show that parenchymal and meningeal inflammations in CNS share a characteristic cytokine profile with a general immune response in the CSF with limited influence from the systemic circulation. IFN-γ activity, assessed by neopterin and IP-10 levels, may play a role in the activation of the KP pathway in these patients, potentially mediating neurotoxic effects.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1366-3) contains supplementary material, which is available to authorized users.

Comparison of Cerebrospinal Fluid Cytokine Levels in Children of Enteroviral Meningitis With Versus Without Pleocytosis

In viral meningitis, proinflammatory cytokines were detected at higher levels in the cerebrospinal fluid (CSF) and might play an important role in the inflammatory process. Our goal was to compare the cytokine profiles in the CSF of children of enteroviral meningitis (EVM) with versus without CSF pleocytosis. In total, 158 patients were enrolled in this prospective cohort study and were classified as EVM (group-A, n = 101), nonenteroviral aseptic meningitis (group-B, n = 27), and control (group-C, n = 30) groups. Of the 101 children with EVM, 71 had CSF pleocytosis (group-A1) and 30 had CSF nonpleocytosis (group-A2). Fifteen cytokines/chemokines in the CSF were measured simultaneously by immunoassay. Significant differences were found in interleukin (IL)-2, IL-6, and IL-8 levels in the CSF across the 3 groups, with the highest levels in group-A, followed by group-B and group-C. The levels of IL-1β, IL-2, IL-6, IL8, IL-10, interferon-γ, and tumor necrosis factor-α were significantly higher in the CSF of group-A1 than in that of group-A2. Group-A2 was significantly younger than group-A1 (3.4 ± 2.8 years versus 5.5 ± 3.2 years, P = 0.016). Significant differences between CSF pleocytosis and nonpleocytosis in EVM appear to be associated with distinct levels of CSF cytokines.

Advances in Biomarker-Guided Therapy for Pediatric- and Adult-Onset Neuroinflammatory Disorders: Targeting Chemokines/Cytokines

The concept and recognized components of “neuroinflammation” are expanding at the intersection of neurobiology and immunobiology. Chemokines (CKs), no longer merely necessary for immune cell trafficking and positioning, have multiple physiologic, developmental, and modulatory functionalities in the central nervous system (CNS) through neuron–glia interactions and other mechanisms affecting neurotransmission. They issue the “help me” cry of neurons and astrocytes in response to CNS injury, engaging invading lymphoid cells (T cells and B cells) and myeloid cells (dendritic cells, monocytes, and neutrophils) (adaptive immunity), as well as microglia and macrophages (innate immunity), in a cascade of events, some beneficial (reparative), others destructive (excitotoxic). Human cerebrospinal fluid (CSF) studies have been instrumental in revealing soluble immunobiomarkers involved in immune dysregulation, their dichotomous effects, and the cells—often subtype specific—that produce them. CKs/cytokines continue to be attractive targets for the pharmaceutical industry with varying therapeutic success. This review summarizes the developing armamentarium, complexities of not compromising surveillance/physiologic functions, and insights on applicable strategies for neuroinflammatory disorders. The main approach has been using a designer monoclonal antibody to bind directly to the chemo/cytokine. Another approach is soluble receptors to bind the chemo/cytokine molecule (receptor ligand). Recombinant fusion proteins combine a key component of the receptor with IgG1. An additional approach is small molecule antagonists (protein therapeutics, binding proteins, and protein antagonists). CK neutralizing molecules (“neutraligands”) that are not receptor antagonists, high-affinity neuroligands (“decoy molecules”), as well as neutralizing “nanobodies” (single-domain camelid antibody fragment) are being developed. Simultaneous, more precise targeting of more than one cytokine is possible using bispecific agents (fusion antibodies). It is also possible to inhibit part of a signaling cascade to spare protective cytokine effects. “Fusokines” (fusion of two cytokines or a cytokine and CK) allow greater synergistic bioactivity than individual cytokines. Another promising approach is experimental targeting of the NLRP3 inflammasome, amply expressed in the CNS and a key contributor to neuroinflammation. Serendipitous discovery is not to be discounted. Filling in knowledge gaps between pediatric- and adult-onset neuroinflammation by systematic collection of CSF data on CKs/cytokines in temporal and clinical contexts and incorporating immunobiomarkers in clinical trials is a challenge hereby set forth for clinicians and researchers.

Neuroinvasion and Inflammation in Viral Central Nervous System Infections

Neurotropic viruses can cause devastating central nervous system (CNS) infections, especially in young children and the elderly. The blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB) have been described as relevant sites of entry for specific viruses as well as for leukocytes, which are recruited during the proinflammatory response in the course of CNS infection. In this review, we illustrate examples of established brain barrier models, in which the specific reaction patterns of different viral families can be analyzed. Furthermore, we highlight the pathogen specific array of cytokines and chemokines involved in immunological responses in viral CNS infections. We discuss in detail the link between specific cytokines and chemokines and leukocyte migration profiles. The thorough understanding of the complex and interrelated inflammatory mechanisms as well as identifying universal mediators promoting CNS inflammation is essential for the development of new diagnostic and treatment strategies.

Analysis of Serum Th1/Th2 Cytokine Levels in Patients with Acute Mumps Infection

BACKGROUND

The mumps virus is frequently the causative agent of parotitis. There has been no study on serum cytokine levels of acute mumps parotitis except for a few which document cytokine levels in cerebrospinal fluid of mumps meningitis. It is with this notion, our study aimed to find Th1/Th2 cytokine levels from patients with acute mumps parotitis.

MATERIALS AND METHODS

Concentrations of mumps-specific IgM, mumps, measles, rubella-specific IgG antibody, and Th1/Th2 cytokines, namely interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4, and IL-10 were measured simultaneously in serum from 74 patients (42 pediatric and 32 adult cases), 40 healthy subjects (20 pediatric and 20 adults) and in the supernatant of peripheral blood mononuclear cells stimulated with mumps virus genotype C which served as the positive control. Statistical significance was analyzed between each group by means of Mann-Whitney U-test, Kruskal-Wallis test, and Spearman's rank correlation coefficient test.

RESULTS

IgM positivity confirmed acute infection in all 74 patients and of these 67 were vaccinated cases; however, very few of them (10/67) were positive for mumps IgG. We found that IFN-γ, IL-2, and IL-10 showed a statistically significant increase in both pediatric and adult patients with acute mumps infection when compared to healthy controls and values were comparable to the positive control.

CONCLUSION

The Th1 cells play important roles during the acute phase of mumps parotitis.

Increased levels of cytokines in cerebrospinal fluid of children with aseptic meningitis caused by mumps virus and echovirus 30

We measured levels of pro-inflammatory cytokines in the cerebrospinal fluid (CSF) of patients with mumps meningitis, enteroviral echovirus 30 meningitis and children without central nervous system infection to investigate whether these molecules were involved in the pathogenesis of viral meningitis. The CSF was obtained from 62 children suspected with meningitis. These patients were classified to the mumps meningitis (n = 19), echovirus 30 meningitis (n = 22) and non-meningitis (n = 21) groups. The concentrations of interleukin-1 (IL-1), interleukin-1 soluble receptor type 2 (IL-1R2), interleukin-8 (IL-8), human interferon gamma (IFN-γ) and human tumour necrosis factor alpha (TNF-α) were determined by immunoassay. A significant increase was noted in the levels of IL-8, TNF-α and IL-1R2 in the CSF of both meningitis groups as compared to controls. The concentrations of IFN-γ and IL-1 differed significantly only between the mumps group and control. The levels of IL-1, IFN-γ and TNF-α were significantly higher in mumps meningitis when compared to the echovirus 30 group. Of all cytokines examined, only IFN-γ correlated with pleocytosis (r = 0.58) in the mumps meningitis group. The increased CSF cytokine levels are markers of meningeal inflammation, and each virus may cause a specific profile of the cytokine pattern.

Immune response to intrathecal enzyme replacement therapy in mucopolysaccharidosis I patients

BACKGROUND

Intrathecal (IT) enzyme replacement therapy with recombinant human α-L-iduronidase (rhIDU) has been studied to treat glycosaminoglycan storage in the central nervous system of mucopolysaccharidosis (MPS) I dogs and is currently being studied in MPS I patients.

METHODS

We studied the immune response to IT rhIDU in MPS I subjects with spinal cord compression who had been previously treated with intravenous rhIDU. We measured the concentrations of specific antibodies and cytokines in serum and cerebrospinal fluid (CSF) collected before monthly IT rhIDU infusions and compared the serologic findings with clinical adverse event (AE) reports to establish temporal correlations with clinical symptoms.

RESULTS

Five MPS I subjects participating in IT rhIDU trials were studied. One subject with symptomatic spinal cord compression had evidence of an inflammatory response with CSF leukocytosis, elevated interleukin-5, and elevated immunoglobulin G. This subject also complained of lower back pain and buttock paresthesias temporally correlated with serologic abnormalities. Clinical symptoms were managed with oral medication, and serologic abnormalities were resolved, although this subject withdrew from the trial to have spinal decompressive surgery.

CONCLUSION

IT rhIDU was generally well tolerated in the subjects studied, although one subject had moderate to severe clinical symptoms and serologic abnormalities consistent with an immune response.