Varicella zoster virus-induced autophagy in human neuronal and hematopoietic cells exerts antiviral activity.

Autophagy is a degradational pathway with pivotal roles in cellular homeostasis and survival, including protection of neurons in the central nervous system (CNS). The significance of autophagy as antiviral defense mechanism is recognized and some viruses hijack and modulate this process to their advantage in certain cell types. Here, we present data demonstrating that the human neurotropic herpesvirus varicella zoster virus (VZV) induces autophagy in human SH-SY5Y neuronal cells, in which the pathway exerts antiviral activity. Productively VZV-infected SH-SY5Y cells showed increased LC3-I-LC3-II conversion as well as co-localization of the viral glycoprotein E and the autophagy receptor p62. The activation of autophagy was dependent on a functional viral genome. Interestingly, inducers of autophagy reduced viral transcription, whereas inhibition of autophagy increased viral transcript expression. Finally, the genotype of patients with severe ocular and brain VZV infection were analyzed to identify potential autophagy-associated inborn errors of immunity. Two patients expressing genetic variants in the autophagy genes ULK1 and MAP1LC3B2, respectively, were identified. Notably, cells of both patients showed reduced autophagy, alongside enhanced viral replication and death of VZV-infected cells. In conclusion, these results demonstrate a neuro-protective role for autophagy in the context of VZV infection and suggest that failure to mount an autophagy response is a potential predisposing factor for development of severe VZV disease.

Alveolar cytokines and interferon autoantibodies in COVID-19 ARDS.

Background: Type I interferon (IFN-I) and IFN autoantibodies play a crucial role in controlling SARS-CoV-2 infection. The levels of these mediators have only rarely been studied in the alveolar compartment in patients with COVID-19 acute respiratory distress syndrome (CARDS) but have not been compared across different ARDS etiologies, and the potential effect of dexamethasone (DXM) on these mediators is not known. Methods: We assessed the integrity of the alveolo-capillary membrane, interleukins, type I, II, and III IFNs, and IFN autoantibodies by studying the epithelial lining fluid (ELF) volumes, alveolar concentration of protein, and ELF-corrected concentrations of cytokines in two patient subgroups and controls. Results: A total of 16 patients with CARDS (four without and 12 with DXM treatment), eight with non-CARDS, and 15 healthy controls were included. The highest ELF volumes and protein levels were observed in CARDS. Systemic and ELF-corrected alveolar concentrations of interleukin (IL)-6 appeared to be particularly low in patients with CARDS receiving DXM, whereas alveolar levels of IL-8 were high regardless of DXM treatment. Alveolar levels of IFNs were similar between CARDS and non-CARDS patients, and IFNα and IFNω autoantibody levels were higher in patients with CARDS and non-CARDS than in healthy controls. Conclusions: Patients with CARDS exhibited greater alveolo-capillary barrier disruption with compartmentalization of IL-8, regardless of DXM treatment, whereas systemic and alveolar levels of IL-6 were lower in the DXM-treated subgroup. IFN-I autoantibodies were higher in the BALF of CARDS patients, independent of DXM, whereas IFN autoantibodies in plasma were similar to those in controls.

Cholesterol-binding motifs in STING that control endoplasmic reticulum retention mediate anti-tumoral activity of cholesterol-lowering compounds.

The cGAS-STING pathway plays a crucial role in anti-tumoral responses by activating inflammation and reprogramming the tumour microenvironment. Upon activation, STING traffics from the endoplasmic reticulum (ER) to Golgi, allowing signalling complex assembly and induction of interferon and inflammatory cytokines. Here we report that cGAMP stimulation leads to a transient decline in ER cholesterol levels, mediated by Sterol O-Acyltransferase 1-dependent cholesterol esterification. This facilitates ER membrane curvature and STING trafficking to Golgi. Notably, we identify two cholesterol-binding motifs in STING and confirm their contribution to ER-retention of STING. Consequently, depletion of intracellular cholesterol levels enhances STING pathway activation upon cGAMP stimulation. In a preclinical tumour model, intratumorally administered cholesterol depletion therapy potentiated STING-dependent anti-tumoral responses, which, in combination with anti-PD-1 antibodies, promoted tumour remission. Collectively, we demonstrate that ER cholesterol sets a threshold for STING signalling through cholesterol-binding motifs in STING and we propose that this could be exploited for cancer immunotherapy.

Prevalence and Patient Characteristics of Ectodermal Dysplasias in Denmark.

Importance: Ectodermal dysplasias constitute a group of rare genetic disorders of the skin and skin appendages with hypodontia, hypotrichosis, and hypohidrosis as cardinal features. There is a lack of population-based research into the epidemiology of ectodermal dysplasias. Objective: To establish a validated population-based cohort of patients with ectodermal dysplasia in Denmark and to assess the disease prevalence and patient characteristics. Design, Setting, and Participants: This nationwide cohort study used individual-level registry data recorded across the Danish universal health care system to identify patients with ectodermal dysplasias from January 1, 1995, to August 25, 2021. A 3-level search of the Danish National Patient Registry and the Danish National Child Odontology Registry was conducted to identify patients with diagnosis codes indicative of ectodermal dysplasias; patients registered in the Danish RAREDIS Database, the Danish Database of Genodermatoses, and local databases were also added. The search results underwent diagnosis validation and review of clinical data using medical records. Of 844 patient records suggestive of ectodermal dysplasias, 791 patients (93.7%) had medical records available for review. Positive predictive values of the diagnosis coding were computed, birth prevalence was estimated, and patient characteristics were identified. Data analysis was performed from May 4 to December 22, 2023. Results: The identified and validated study cohort included 396 patients (median [IQR] age at diagnosis, 13 [4-30] years, 246 females [62.1%]), of whom 319 had confirmed ectodermal dysplasias and 77 were likely cases. The combined positive predictive value (PPV) for ectodermal dysplasia-specific diagnosis codes was 67.0% (95% CI, 62.7%-71.0%). From 1995 to 2011, the estimated minimum birth prevalence per 100 000 live births was 14.5 (95% CI, 12.2-16.7) for all ectodermal dysplasias and 2.8 (95% CI, 1.8-3.8) for X-linked hypohidrotic ectodermal dysplasias. A molecular genetic diagnosis was available for 241 patients (61%), including EDA (n = 100), IKBKG (n = 55), WNT10A (n = 21), TRPS1 (n = 18), EDAR (n = 10), P63 (n = 9), GJB6 (n = 9), PORCN (n = 7), and other rare genetic variants. Conclusions and Relevance: The findings of this nationwide cohort study indicate that the prevalence of ectodermal dysplasias was lower than previously reported. Furthermore, PPVs of the search algorithms emphasized the importance of diagnosis validation. The establishment of a large nationwide cohort of patients with ectodermal dysplasias, including detailed clinical and molecular data, is a unique resource for future research in ectodermal dysplasias.

The HIF transcription network exerts innate antiviral activity in neurons and limits brain inflammation.

Pattern recognition receptors (PRRs) induce host defense but can also induce exacerbated inflammatory responses. This raises the question of whether other mechanisms are also involved in early host defense. Using transcriptome analysis of disrupted transcripts in herpes simplex virus (HSV)-infected cells, we find that HSV infection disrupts the hypoxia-inducible factor (HIF) transcription network in neurons and epithelial cells. Importantly, HIF activation leads to control of HSV replication. Mechanistically, HIF activation induces autophagy, which is essential for antiviral activity. HSV-2 infection in vivo leads to hypoxia in CNS neurons, and mice with neuron-specific HIF1/2α deficiency exhibit elevated viral load and augmented PRR signaling and inflammatory gene expression in the CNS after HSV-2 infection. Data from human stem cell-derived neuron and microglia cultures show that HIF also exerts antiviral and inflammation-restricting activity in human CNS cells. Collectively, the HIF transcription factor system senses virus-induced hypoxic stress to induce cell-intrinsic antiviral responses and limit inflammation.

Impaired STING Activation Due to a Variant in the E3 Ubiquitin Ligase AMFR in a Patient with Severe VZV Infection and Hemophagocytic Lymphohistiocytosis.

Varicella zoster virus (VZV) is a neurotropic alphaherpesvirus exclusively infecting humans, causing two distinct pathologies: varicella (chickenpox) upon primary infection and herpes zoster (shingles) following reactivation. In susceptible individuals, VZV can give rise to more severe clinical manifestations, including disseminated infection, pneumonitis, encephalitis, and vasculopathy with stroke. Here, we describe a 3-year-old boy in whom varicella followed a complicated course with thrombocytopenia, hemorrhagic and necrotic lesions, pneumonitis, and intermittent encephalopathy. Hemophagocytic lymphohistiocytosis (HLH) was strongly suspected and as the condition deteriorated, HLH therapy was initiated. Although the clinical condition improved, longstanding hemophagocytosis followed despite therapy. We found that the patient carries a rare monoallelic variant in autocrine motility factor receptor (AMFR), encoding a ubiquitin ligase involved in innate cytosolic DNA sensing and interferon (IFN) production through the cyclic GMP-AMP synthase-stimulator of IFN genes (cGAS-STING) pathway. Peripheral blood mononuclear cells (PBMCs) from the patient exhibited impaired signaling downstream of STING in response dsDNA and 2'3'-cGAMP, agonists of cGAS and STING, respectively, and fibroblasts from the patient showed impaired type I IFN responses and significantly increased VZV replication. Overexpression of the variant AMFR R594C resulted in decreased K27-linked STING ubiquitination compared to WT AMFR. Moreover, ImageStream technology revealed reduced STING trafficking from ER to Golgi in cells expressing the patient AMFR R594C variant. This was supported by a dose-dependent dominant negative effect of expression of the patient AMFR variant as measured by IFN-ß reporter gene assay. Finally, lentiviral transduction with WT AMFR partially reconstituted 2'3'-cGAMP-induced STING-mediated signaling and ISG expression in patient PBMCs. This work links defective AMFR-STING signaling to severe VZV disease and hyperinflammation and suggests a direct role for cGAS-STING in the control of viral infections in humans. In conclusion, we describe a novel genetic etiology of severe VZV disease in childhood, also representing the first inborn error of immunity related to a defect in the cGAS-STING pathway.

An IKBKE variant conferring functional cGAS/STING pathway deficiency and susceptibility to recurrent HSV-2 meningitis.

The mechanisms underlying susceptibility to recurrent herpes simplex virus type 2 (HSV-2) meningitis remain incompletely understood. In a patient experiencing multiple episodes of HSV-2 meningitis, we identified a monoallelic variant in the IKBKE gene, which encodes the IKKε kinase involved in induction of antiviral IFN genes. Patient cells displayed impaired induction of IFN-ß1 (IFNB1) expression upon infection with HSV-2 or stimulation with double-stranded DNA (dsDNA) and failed to induce phosphorylation of STING, an activation marker of the DNA-sensing cyclic GMP-AMP synthase/stimulator of IFN genes (cGAS/STING) pathway. The patient allele encoded a truncated IKKε protein with loss of kinase activity and also capable of exerting dominant-negative activity. In stem cell-derived microglia, HSV-2-induced expression of IFNB1 was dependent on cGAS, TANK binding kinase 1 (TBK1), and IKBKE, but not TLR3, and supernatants from HSV-2-treated microglia exerted IKBKE-dependent type I IFN-mediated antiviral activity upon neurons. Reintroducing wild-type IKBKE into patient cells rescued IFNB1 induction following treatment with HSV-2 or dsDNA and restored antiviral activity. Collectively, we identify IKKε to be important for protection against HSV-2 meningitis and suggest a nonredundant role for the cGAS/STING pathway in human antiviral immunity.

Whole exome sequencing of patients with varicella-zoster virus and herpes simplex virus induced acute retinal necrosis reveals rare disease-associated genetic variants.

Purpose: Herpes simplex virus (HSV) and varicella-zoster virus (VZV) are neurotropic human alphaherpesviruses endemic worldwide. Upon primary infection, both viruses establish lifelong latency in neurons and reactivate intermittently to cause a variety of mild to severe diseases. Acute retinal necrosis (ARN) is a rare, sight-threatening eye disease induced by ocular VZV or HSV infection. The virus and host factors involved in ARN pathogenesis remain incompletely described. We hypothesize an underlying genetic defect in at least part of ARN cases. Methods: We collected blood from 17 patients with HSV-or VZV-induced ARN, isolated DNA and performed Whole Exome Sequencing by Illumina followed by analysis in Varseq with criteria of CADD score > 15 and frequency in GnomAD < 0.1% combined with biological filters. Gene modifications relative to healthy control genomes were filtered according to high quality and read-depth, low frequency, high deleteriousness predictions and biological relevance. Results: We identified a total of 50 potentially disease-causing genetic variants, including missense, frameshift and splice site variants and on in-frame deletion in 16 of the 17 patients. The vast majority of these genes are involved in innate immunity, followed by adaptive immunity, autophagy, and apoptosis; in several instances variants within a given gene or pathway was identified in several patients. Discussion: We propose that the identified variants may contribute to insufficient viral control and increased necrosis ocular disease presentation in the patients and serve as a knowledge base and starting point for the development of improved diagnostic, prophylactic, and therapeutic applications.

Examination of autoantibodies to type I interferon in patients suffering from long COVID.

Long COVID (LC) is an emerging global health concern. The underlying mechanism and pathophysiology remain unclear. Presence of neutralizing autoantibodies against type 1 interferons (IFN) has been established as a predictor of critical COVID-19. We hypothesized that persistent autoimmune activity with autoantibodies against type 1 IFN may contribute to symptoms in patients with LC. Plasma samples and clinical information were obtained from a Danish LC cohort consisting of adult patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Information on symptoms and quality of life was derived from an LC-specific questionnaire and the EQ-5D-5L questionnaire. Detection of type 1 IFN autoantibodies in plasma were performed by ELISA. Samples collected between June, 2020, and September, 2021, from 279 patients were analyzed and compared to a control group of 94 individuals with prior mild SARS-CoV-2 infection who did not develop LC symptoms. In total, five LC patients (1.8%) and 3 (3.2%) of the controls had detectable circulating type 1 IFN autoantibodies. Collectively, prevalence of autoantibodies against type 1 IFN subtypes in our LC cohort were primarily driven by men and did not exceed the prevalence in controls. Thus, in our cohort, anti-type I IFN autoantibodies are unlikely to drive LC symptoms.

A Novel CDC42 Variant with Impaired Thymopoiesis, IL-7R Signaling, PAK1 Binding, and TCR Repertoire Diversity.

Genetic variants in cell division cycle 42 (CDC42) can manifest with dysmorphic features, autoinflammation, hemophagocytic lymphohistiocytosis, and thrombocytopenia, whereas defective thymopoiesis is a rare disease manifestation. We report a novel CDC42 missense variant (c.46A > G, p.Lys16Glu) resulting in infection and HPV-driven carcinogenesis in the mosaic mother and impaired thymopoiesis and profound T cell lymphopenia in the heterozygous daughter identified through newborn screening for SCID. We found that surface expression of IL-7Rα (CD127) was decreased, consistent with reduced IL-7-induced STAT5 phosphorylation and accelerated apoptotic T cell death. Consistent with the vital role of IL-7 in regulating thymopoiesis, both patients displayed reduced T cell receptor CDR3 repertoires. Moreover, the CDC42 variant prevented binding to the downstream effector, p21-activated kinase (PAK)1, suggesting this impaired interaction to underlie reduced IL-7Rα expression and signaling. Here, we provide the first report of severely compromised thymopoiesis and perturbed IL-7Rα signaling caused by a novel CDC42 variant and presenting with diverging clinical and immunological phenotypes in patients.

Autoantibodies Neutralizing Type III Interferons Are Uncommon in Patients with Severe Coronavirus Disease 2019 Pneumonia.

Autoantibodies (AABs) neutralizing type I interferons (IFN) underlie about 15% of cases of critical coronavirus disease 2019 (COVID-19) pneumonia. The impact of autoimmunity toward type III IFNs remains unexplored. We included samples from 1,002 patients with COVID-19 (50% with severe disease) and 1,489 SARS-CoV-2-naive individuals. We studied the prevalence and neutralizing capacity of AABs toward IFNλ and IFNα. Luciferase-based immunoprecipitation method was applied using pooled IFNα (subtypes 1, 2, 8, and 21) or pooled IFNλ1-IFNλ3 as antigens, followed by reporter cell-based neutralization assay. In the SARS-CoV-2-naive cohort, IFNλ AABs were more common (8.5%) than those targeting IFNα2 (2.9%) and were related with older age. In the COVID-19 cohort the presence of autoreactivity to IFNλ did not associate with severe disease [odds ratio (OR) 0.84; 95% confidence interval (CI) 0.40-1.73], unlike to IFNα (OR 4.88; 95% CI 2.40-11.06; P < 0.001). Most IFNλ AAB-positive COVID-19 samples (67%) did not neutralize any of the 3 IFNλ subtypes. Pan-IFNλ neutralization occurred in 5 patients (0.50%), who all suffered from severe COVID-19 pneumonia, and 4 of them neutralized IFNα2 in addition to IFNλ. Overall, AABs to type III IFNs are rarely neutralizing, and do not seem to predispose to severe COVID-19 pneumonia on their own.

Inborn Errors of Immunity Predisposing to Herpes Simplex Virus Infections of the Central Nervous System.

Herpesvirus infections can lead to a number of severe clinical manifestations, particularly when involving the central nervous system (CNS), causing encephalitis and meningitis. However, understanding of the host factors conferring increased susceptibility to these diseases and their complications remains incomplete. Previous studies have uncovered defects in the innate Toll-like receptor 3 pathway and production of type I interferon (IFN-I) in children and adults that predispose them to herpes simplex encephalitis. More recently, there is accumulating evidence for an important role of IFN-independent cell-autonomous intrinsic mechanisms, including small nucleolar RNAs, RNA lariat metabolism, and autophagy, in restricting herpesvirus replication and conferring protection against CNS infection. The present review first describes clinical manifestations of HSV infection with a focus on neurological complications and then summarizes the host-pathogen interactions and innate immune pathways responsible for sensing herpesviruses and triggering antiviral responses and immunity. Next, we review the current landscape of inborn errors of immunity and the underlying genetic defects and disturbances of cellular immune pathways that confer increased susceptibility to HSV infection in CNS. Ultimately, we discuss some of the present outstanding unanswered questions relating to inborn errors of immunity and HSV CNS infection together with some perspectives and future directions for research in the pathogenesis of these severe diseases in humans.

Successful use of interferon alfa-2a for persistent parvovirus B19 infection.

Human infection with parvovirus B19 causes a range of clinical manifestations, including benign erythema infectiosum in children, arthralgias in adults, aplastic crisis in patients with bone marrow failure, and potentially fatal congenital hydrops fetalis. Persistent parvovirus B19 infection is a rare disease presentation mostly seen in adult women or immunocompromised individuals. Treatment options include corticosteroids and intravenous immunoglobulin; however, viral clearance is difficult to obtain and rarely maintained. In this Grand Round, we report the case of a 43-year-old man with persistent parvovirus B19 infection and anaemia, who was refractory to standard treatment regimens, and whom we successfully treated with pegylated interferon alfa-2a. Initial treatment led to viral clearance and remission of anaemia, although secondary recurrence of virus required treatment extension. Despite extensive genetic and immunological evaluations, no underlying primary or secondary immunodeficiency was identified in the patient. We propose interferon alfa-2a as a treatment option for persistent parvovirus B19 infection and advocate long-term follow-up of patients and potentially repeated treatment.

High-dose coenzyme Q10 therapy versus placebo in patients with post COVID-19 condition: a randomized, phase 2, crossover trial.

Background: Post COVID-19 condition (PCC) is defined as symptoms lasting more than 12 weeks after developing COVID-19. Evidence of mitochondrial dysfunction has been reported in peripheral blood mononuclear cells obtained from patients with COVID-19. We hypothesized that PCC is caused by prolonged mitochondrial dysfunction. Given that coenzyme Q10 (CoQ10) can improve mitochondrial function, we examined whether high-dose CoQ10 can reduce the number and/or severity of PCC-related symptoms. Methods: In this placebo-controlled, double-blind, 2 × 2 crossover interventional trial, participants were recruited from two centres at Aarhus University Hospital and Gødstrup Hospital, Denmark. They were randomly assigned to receive either oral capsules of CoQ10 in a dose of 500 mg/day or placebo for 6 weeks, with crossover treatment after a 4-week washout period. The ED-5Q and a PCC-symptom specific questionnaire were completed by the participants at 5 visits during the 20-week study period. The primary endpoint was the change in the number and/or severity of PCC-related symptoms after the 6-week intervention compared to placebo. Participants who completed the two-dosing period were included in the primary analysis, while all participants receiving one dose were included in safety assessment. Findings: From May 25th, 2021, to September 22nd, 2021, 121 participants underwent randomization, and 119 completed both dosing periods - 59 and 60 in group A and B, respectively. At baseline, the mean PCC-related symptom score was 43.06 (95% CI: 40.18; 45.94), and the mean EQ-5D health index was 0.66 (95% CI: 0.64; 0.68). The difference between CoQ10 and placebo was not significant with respect to either the change in EQ-5D health index (with a mean difference of 0.01; 95% CI: -0.02; 0.04; p = 0.45) or the change in PCC-related symptom score (with a mean difference of -1.18; 95% CI: -3.54; 1.17; p = 0.32). Interpretation: Based on self-reported data, CoQ10 treatment does not appear to significantly reduce the number or severity of PCC-related symptoms when compared to placebo. However, we observed a significant spontaneous improvement on both scores regardless of treatment during 20 weeks observation. Funding: Placebo and CoQ10 capsules were provided by Pharma Nord, and the trial was supported by grants from the Novo Nordisk Foundation (NNF21OC0066984). This trial is registered with EudraCT, 2020-005961-16 and ClinicalTrials.gov, NCT04960215. The trial is completed.

Case report: Evolution of pulmonary manifestations and virological markers in critical COVID-19 infection in Bruton's agammaglobulinemia.

Despite several reports and small case series on the disease course of SARS-CoV-2 infection in patients with inborn errors of immunity (IEI), including X-linked agammaglobulinemia (XLA), this topic remains incompletely described. Here we present the case of a 38-year-old unvaccinated man with XLA, who acquired SARS-CoV-2 infection and experienced a protracted disease course with 47 days of SARS-CoV-2 positivity, critical COVID-19 with respiratory insufficiency necessitating intensive care and ventilatory support, and prompting repeated intensified treatments with remdesivir, dexamethasone, and monoclonal antibodies to eventually control infection. We describe the disease course and treatment and review the current literature on COVID-19 susceptibility and evidence for vaccine efficacy in patients with XLA.

[Local immunopathology in COVID-19 associated lung injury].

Mechanisms of COVID-19-induced lung injury involve complex immunopathological events which are currently being elucidated. Studying immune mechanisms at the primary site of injury, i.e. the lower airways, are particularly informative. This review provides a brief introduction to the methods used to perform sampling from the lungs of critically ill patients with COVID-19, key immunopathological findings and a discussion on how immunosuppressants may exert their effects locally.

A Distinct Dexamethasone-Dependent Gene Expression Profile in the Lungs of COVID-19 Patients.

The effects of dexamethasone (DXM) treatment on pulmonary immunity in COVID-19-associated acute respiratory distress syndrome (CARDS) remain insufficiently understood. We performed transcriptomic RNA-seq analysis of bronchoalveolar lavage fluid from 20 mechanically ventilated patients: 12 with CARDS (with or without DXM) and 8 non-COVID-19 critically ill controls. CARDS with DXM was characterized by upregulation of genes related to B-cell and complement pathway activation, antigen presentation, phagocytosis, and FC-γ receptor signaling. Most interferon-stimulated genes were upregulated in CARDS, particularly in CARDS without DXM. In conclusion, DXM treatment was not associated with regulation of proinflammatory pathways in CARDS but with regulation of other local immune responses. Clinical Trials Registration. NCT04354584.