Context Is Key: Delineating the Unique Functions of IFNα and IFNβ in Disease

Personalised medicine in juvenile dermatomyositis: From novel insights in disease mechanisms to changes in clinical practice

Juvenile dermatomyositis is characterized by childhood-onset chronic inflammation of the muscles and skin, with potential involvement of other organs. Patients are at risk for long-term morbidity due to insufficient disease control and steroid-related toxicity. Personalised treatment is challenged by a lack of validated tools that can reliably predict treatment response and monitor ongoing (subclinical) inflammation, and by a lack of evidence regarding the best choice of medication for individual patients. A better understanding of the involved disease mechanisms could reveal potential biomarkers and novel therapeutic targets. In this review, we highlight the most relevant immune and non-immune mechanisms, elucidating the effects of interferon overexpression on tissue alongside the interplay between the interferon signature, mitochondrial function, and immune cells. We review mechanism-based biomarkers that are promising for clinical implementation, and the latest advances in targeted therapy development. Finally, we discuss key steps needed for translating these discoveries into clinical practice.

Nebulised interferon beta-1a (SNG001) in the treatment of viral exacerbations of COPD

BACKGROUND

Respiratory viral infections are major drivers of chronic obstructive pulmonary disease (COPD) exacerbations. Interferon-β is naturally produced in response to viral infection, limiting replication. This exploratory study aimed to demonstrate proof-of-mechanism, and evaluate the efficacy and safety of inhaled recombinant interferon-β1a (SNG001) in COPD. Part 1 assessed the effects of SNG001 on induced sputum antiviral interferon-stimulated gene expression, sputum differential cell count, and respiratory function. Part 2 compared SNG001 and placebo on clinical efficacy, sputum and serum biomarkers, and viral clearance.

METHODS

In Part 1, patients (N = 13) with stable COPD were randomised 4:1 to SNG001 or placebo once-daily for three days. In Part 2, patients (N = 109) with worsening symptoms and a positive respiratory viral test were randomised 1:1 to SNG001 or placebo once-daily for 14 days in two Groups: A (no moderate exacerbation); B (moderate COPD exacerbation [i.e., acute worsening of respiratory symptoms treated with antibiotics and/or oral corticosteroids]).

RESULTS

In Part 1, SNG001 upregulated sputum interferon gene expression. In Part 2, there were minimal SNG001-placebo differences in the efficacy endpoints; however, whereas gene expression was initially upregulated by viral infection, then declined on placebo, levels were maintained with SNG001. Furthermore, the proportion of patients with detectable rhinovirus (the most common virus) on Day 7 was lower with SNG001. In Group B, serum C-reactive protein and the proportion of patients with purulent sputum increased with placebo (suggesting bacterial infection), but not with SNG001. The overall adverse event incidence was similar with both treatments.

CONCLUSIONS

Overall, SNG001 was well-tolerated in patients with COPD, and upregulated lung antiviral defences to accelerate viral clearance. These findings warrant further investigation in a larger study.

TRIAL REGISTRATION

EU clinical trials register (2017-003679-75), 6 October 2017.

Feasibility of Using a Type I IFN-Based Non-Animal Approach to Predict Vaccine Efficacy and Safety Profiles

Animal-based tests are used for the control of vaccine quality. However, because highly purified and safe vaccines are now available, alternative approaches that can replace or reduce animal use for the assessment of vaccine outcomes must be established. In vitro tests for vaccine quality control exist and have already been implemented. However, these tests are specifically designed for some next-generation vaccines, and this makes them not readily available for testing other vaccines. Therefore, universal non-animal tests are still needed. Specific signatures of the innate immune response could represent a promising approach to predict the outcome of vaccines by non-animal methods. Type I interferons (IFNs) have multiple immunomodulatory activities, which are exerted through effectors called interferon stimulated genes (ISGs), and are one of the most important immune signatures that might provide potential candidate molecular biomarkers for this purpose. This paper will mainly examine if this idea might be feasible by analyzing all relevant published studies that have provided type I IFN-related biomarkers for evaluating the safety and efficacy profiles of vaccines using an advanced transcriptomic approach as an alternative to the animal methods. Results revealed that such an approach could potentially provide biomarkers predictive of vaccine outcomes after addressing some limitations.

Type I interferon pathway genetic variants in severe COVID-19

Coronavirus Disease 2019 (COVID-19) is an infectious disease caused by SARS-CoV-2. According to the World Health Organization (WHO), there have been over 760 million reported cases and over 6 million deaths caused by this disease worldwide. The severity of COVID-19 is based on symptoms presented by the patient and is divided as asymptomatic, mild, moderate, severe, and critical. The manifestations are interconnected with genetic variations. The innate immunity is the quickest response mechanism of an organism against viruses. Type I interferon pathway plays a key role in antiviral responses due to viral replication inhibition in infected cells and adaptive immunity stimulation induced by interferon molecules. Thus, variants in type I interferon pathway's genes are being studied in different COVID-19 manifestations. This review summarizes the role of variants in type I interferon pathway's genes on prognosis and severity progression of COVID-19.

Transcriptome Analysis Reveals Anti-Cancer Effects of Isorhapontigenin (ISO) on Highly Invasive Human T24 Bladder Cancer Cells

Bladder cancer, the most common malignancy of the urinary tract, has a poor overall survival rate when the tumor becomes muscle invasive. The discovery and evaluation of new alternative medications targeting high-grade muscle invasive bladder cancer (MIBC) are of tremendous importance in reducing bladder cancer mortality. Isorhapontigenin (ISO), a stilbene derivative from the Chinese herb Gnetum cleistostachyum, exhibits a strong anti-cancer effect on MIBCs. Here, we report the whole transcriptome profiling of ISO-treated human bladder cancer T24 cells. A total of 1047 differentially expressed genes (DEGs) were identified, including 596 downregulated and 451 upregulated genes. Functional annotation and pathway analysis revealed that ISO treatment induced massive changes in gene expression associated with cell movement, migration, invasion, metabolism, proliferation, and angiogenesis. Additionally, ISO treatment-activated genes involved in the inflammatory response but repressed genes involved in hypoxia signaling, glycolysis, the actin cytoskeleton, and the tumor microenvironment. In summary, our whole transcriptome analysis demonstrated a shift in metabolism and altered actin cytoskeleton in ISO-treated T24 cells, which subsequently contribute to tumor microenvironment remodeling that suppresses tumor growth and progression.

Feasibility of home administration of nebulised interferon ß-1a (SNG001) for COVID-19: a remote study

BACKGROUND

Effective therapeutics given early to high-risk ambulatory patients with coronavirus disease 2019 (COVID-19) could improve outcomes and reduce overall healthcare burden. However, conducting site visits in non-hospitalised patients, who should remain isolated, is problematic.

AIM

To evaluate the feasibility of a purely remote (virtual) study in non-hospitalised patients with COVID-19; and the efficacy and safety of nebulised recombinant interferon-β1a (SNG001) in this setting.

DESIGN & SETTING

Randomised, double-blind, parallel-group study, which was conducted remotely.

METHOD

Eligible patients aged ≥65 years (or ≥50 years with risk factors) with COVID-19 and not requiring hospital admission were recruited remotely. They were randomised to SNG001 or placebo once-daily via nebuliser for 14 days. The main outcomes were assessments of feasibility and safety, which were all conducted remotely.

RESULTS

Of 114 patients treated, 111 (97.4%) completed 28 days of follow-up. Overall compliance to study medication was high, with ≥13 doses taken by 89.7% and 92.9% of treated patients in the placebo and SNG001 groups, respectively. Over the course of the study, only two patients were hospitalised, both in the placebo group; otherwise there were no notable differences between treatments for the efficacy parameters. No patients withdrew owing to an adverse event, and a similar proportion of patients experienced on-treatment adverse events in the two treatment groups (64.3% and 67.2% with SNG001 and placebo, respectively); most were mild or moderate and not treatment-related.

CONCLUSION

This study demonstrated that it is feasible to conduct a purely virtual study in community-based patients with COVID-19, when the study included detailed daily assessments and with medication administered via nebuliser.

Combined therapy of local recombinant human interferon α1b injection and acupuncture on verruca vulgaris: a retrospective study

Verruca vulgaris is always stubborn to treat. We applied a new combined therapy of local recombinant human interferon alpha 1b (rhIFNα1b) injection plus acupuncture on verruca vulgaris recently to evaluate the efficacy and safety of the combined therapy. The retrospective study was conducted in The First Hospital of China Medical University from 2018 to 2020. Patients with verruca vulgaris were included. Combined therapy with local rhIFNα1b injection plus acupuncture was set as treatment group, rhIFNα1b injection and carbon dioxide (CO2) laser were set as control groups. A total of 2415 patients were included in the study. The cure rates were 81.85%, 85.93%, and 100% in combined group, rhIFNα1b group, and CO2 laser group, separately. All lesions cured in combined group were located on hands or feet, while majority of lesions cured in other groups were located on other sites. For patients with medium/big single lesion or 6-9 lesions, less treatment times were needed in combined group than rhIFNα1b group. For patients with small single, two to five or more than ten lesions, the treatment times of combined group and rhIFNα1b group were comparable. All patients complained of pain in varying degrees when local injection or laser irradiation. Compared with CO2 laser group, more fever, less swelling or scar was reported in combined group. In conclusion, combined therapy of local rhIFNα1b plus acupuncture was beneficial for verruca vulgaris with limited adverse effects. The therapy was more acceptable by younger female patients with verruca vulgaris.

Endothelial type I interferon response and brain diseases: identifying STING as a therapeutic target

The endothelium layer lining the inner surface of blood vessels serves relevant physiological functions in all body systems, including the exchanges between blood and extravascular space. However, endothelial cells also participate in innate and adaptive immune response that contribute to the pathophysiology of inflammatory disorders. Type I Interferon (IFN) signaling is an inflammatory response triggered by a variety of pathogens, but it can also be induced by misplaced DNA in the cytosol caused by cell stress or gene mutations. Type I IFN produced by blood leukocytes or by the endothelium itself is well-known to activate the interferon receptor (IFNAR) in endothelial cells. Here, we discuss the induction of type I IFN secretion and signaling in the endothelium, specifically in the brain microvasculature where endothelial cells participate in the tight blood-brain barrier (BBB). This barrier is targeted during neuroinflammatory disorders such as infection, multiple sclerosis, Alzheimer's disease and traumatic brain injury. We focus on type I IFN induction through the cGAS-STING activation pathway in endothelial cells in context of autoinflammatory type I interferonopathies, inflammation and infection. By comparing the pathophysiology of two separate infectious diseases-cerebral malaria induced by Plasmodium infection and COVID-19 caused by SARS-CoV-2 infection-we emphasize the relevance of type I IFN and STING-induced vasculopathy in organ dysfunction. Investigating the role of endothelial cells as active type I IFN producers and responders in disease pathogenesis could lead to new therapeutic targets. Namely, endothelial dysfunction and brain inflammation may be avoided with strategies that target excessive STING activation in endothelial cells.

Mutant p53 leads to low-grade IFN-I-induced inflammation and impairs cGAS-STING signalling in mice

Type I interferons (IFN-Is) are a class of proinflammatory cytokines produced in response to viruses and environmental stimulations, resulting in chronic inflammation and even carcinogenesis. However, the connection between IFN-I and p53 mutation is poorly understood. Here, we investigated IFN-I status in the context of mutant p53 (p53N236S , p53S). We observed significant cytosolic double-stranded DNA (dsDNA) derived from nuclear heterochromatin in p53S cells, along with an increased expression of IFN-stimulated genes. Further study revealed that p53S promoted cyclic GMP-AMP synthase (cGAS) and IFN-regulatory factor 9 (IRF9) expression, thus activating the IFN-I pathway. However, p53S/S mice were more susceptible to herpes simplex virus 1 infection, and the cGAS-stimulator of IFN genes (STING) pathway showed a decline trend in p53S cells in response to poly(dA:dT) accompanied with decreased IFN-β and IFN-stimulated genes, whereas the IRF9 increased in response to IFN-β stimulation. Our results illustrated the p53S mutation leads to low-grade IFN-I-induced inflammation via consistent low activation of the cGAS-STING-IFN-I axis, and STAT1-IRF9 pathway, therefore, impairs the protective cGAS-STING signalling and IFN-I response encountered with exogenous DNA attack. These results suggested the dual molecular mechanisms of p53S mutation in inflammation regulation. Our results could be helping in further understanding of mutant p53 function in chronic inflammation and provide information for developing new therapeutic strategies for chronic inflammatory diseases or cancer.

Immunomodulatory Role of Interferons in Viral and Bacterial Infections

Interferons are a group of immunomodulatory substances produced by the human immune system in response to the presence of pathogens, especially during viral and bacterial infections. Their remarkably diverse mechanisms of action help the immune system fight infections by activating hundreds of genes involved in signal transduction pathways. In this review, we focus on discussing the interplay between the IFN system and seven medically important and challenging viruses (herpes simplex virus (HSV), influenza, hepatitis C virus (HCV), lymphocytic choriomeningitis virus (LCMV), human immunodeficiency virus (HIV), Epstein-Barr virus (EBV), and SARS-CoV coronavirus) to highlight the diversity of viral strategies. In addition, the available data also suggest that IFNs play an important role in the course of bacterial infections. Research is currently underway to identify and elucidate the exact role of specific genes and effector pathways in generating the antimicrobial response mediated by IFNs. Despite the numerous studies on the role of interferons in antimicrobial responses, many interdisciplinary studies are still needed to understand and optimize their use in personalized therapeutics.

STAM and Hrs interact sequentially with IFN-α Receptor to control spatiotemporal JAK-STAT endosomal activation

Activation of the JAK-STAT pathway by type I interferons (IFNs) requires clathrin-dependent endocytosis of the IFN-α and -β receptor (IFNAR), indicating a role for endosomal sorting in this process. The molecular machinery that brings the selective activation of IFN-α/β-induced JAK-STAT signalling on endosomes remains unknown. Here we show that the constitutive association of STAM with IFNAR1 and TYK2 kinase at the plasma membrane prevents TYK2 activation by type I IFNs. IFN-α-stimulated IFNAR endocytosis delivers the STAM-IFNAR complex to early endosomes where it interacts with Hrs, thereby relieving TYK2 inhibition by STAM and triggering signalling of IFNAR at the endosome. In contrast, when stimulated by IFN-β, IFNAR signalling occurs independently of Hrs as IFNAR is sorted to a distinct endosomal subdomain. Our results identify the molecular machinery that controls the spatiotemporal activation of IFNAR by IFN-α and establish the central role of endosomal sorting in the differential regulation of JAK-STAT signalling by IFN-α and IFN-β.

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.

Effect of regulatory cell death on the occurrence and development of head and neck squamous cell carcinoma

Head and neck cancer is a malignant tumour with a high mortality rate characterized by late diagnosis, high recurrence and metastasis rates, and poor prognosis. Head and neck squamous cell carcinoma (HNSCC) is the most common type of head and neck cancer. Various factors are involved in the occurrence and development of HNSCC, including external inflammatory stimuli and oncogenic viral infections. In recent years, studies on the regulation of cell death have provided new insights into the biology and therapeutic response of HNSCC, such as apoptosis, necroptosis, pyroptosis, autophagy, ferroptosis, and recently the newly discovered cuproptosis. We explored how various cell deaths act as a unique defence mechanism against cancer emergence and how they can be exploited to inhibit tumorigenesis and progression, thus introducing regulatory cell death (RCD) as a novel strategy for tumour therapy. In contrast to accidental cell death, RCD is controlled by specific signal transduction pathways, including TP53 signalling, KRAS signalling, NOTCH signalling, hypoxia signalling, and metabolic reprogramming. In this review, we describe the molecular mechanisms of nonapoptotic RCD and its relationship to HNSCC and discuss the crosstalk between relevant signalling pathways in HNSCC cells. We also highlight novel approaches to tumour elimination through RCD.

Alum-anchored intratumoral retention improves the tolerability and antitumor efficacy of type I interferon therapies

Effective antitumor immunity in mice requires activation of the type I interferon (IFN) response pathway. IFNα and IFNβ therapies have proven promising in humans, but suffer from limited efficacy and high toxicity. Intratumoral IFN retention ameliorates systemic toxicity, but given the complexity of IFN signaling, it was unclear whether long-term intratumoral retention of type I IFNs would promote or inhibit antitumor responses. To this end, we compared the efficacy of IFNα and IFNβ that exhibit either brief or sustained retention after intratumoral injection in syngeneic mouse tumor models. Significant enhancement in tumor retention, mediated by anchoring these IFNs to coinjected aluminum-hydroxide (alum) particles, greatly improved both their tolerability and efficacy. The improved efficacy of alum-anchored IFNs could be attributed to sustained pleiotropic effects on tumor cells, immune cells, and nonhematopoietic cells. Alum-anchored IFNs achieved high cure rates of B16F10 tumors upon combination with either anti-PD-1 antibody or interleukin-2. Interestingly however, these alternative combination immunotherapies yielded disparate T cell phenotypes and differential resistance to tumor rechallenge, highlighting important distinctions in adaptive memory formation for combinations of type I IFNs with other immunotherapies.

Comparison by Age of the Local Interferon Response to SARS-CoV-2 Suggests a Role for IFN-ε and -ω

Children generally develop a mild disease after SARS-CoV-2 infection whereas older adults are at risk of developing severe COVID-19. Recent transcriptomic analysis showed pre-activated innate immunity in children, resulting in a more effective anti-SARS-CoV-2 response upon infection. To further characterize age-related differences, we studied type I and III interferon (IFN) response in SARS-CoV-2 infected and non-infected individuals of different ages. Specifically, levels of expression of type I (IFN-α, -β, -ε and -ω), type III (IFN-λ1, -λ2 and -λ3) IFNs and of the IFN-stimulated genes, ISG15 and ISG56 were quantified in nasopharyngeal cells from diagnostic swabs. Basal transcription of type I/III IFN genes was highest among children and decreased with age. Among SARS-CoV-2-infected individuals, only IFN-ε and -ω levels were significantly higher in children and young adults whereas ISGs were overexpressed in infected adults. The occurrence of symptoms in children and the need for hospitalization in adults were associated to higher transcription of several IFN genes. Starting from a pre-activated transcription level, the expression of type I and III IFNs was not highly up-regulated in children upon SARS-CoV-2 infection; young adults activated IFNs’ transcription at intermediate levels whereas older adults were characterized by higher ISGs and lower IFN-ε and -ω relative expression levels. Overall, our findings contribute to recognize components of a protective IFN response as a function of age, in the context of SARS-CoV-2 infection.

Types of Interferons and Their Expression in Plant Systems

Interferons (IFNs) are divided into 3 types (type I, type II, and type III) on the basis of sequence homology and functional properties. Recombinant IFNs have been approved by regulatory agencies in many countries for clinical treatment of hepatitis B, hepatitis C, and other diseases; these IFNs are mainly produced in microorganisms and mammalian cell systems. However, there are serious obstacles to the production of recombinant IFNs in microorganism systems; for example, the recombinant IFN may have different glycosylation patterns from the native protein, be present in insoluble inclusion bodies, be contaminated with impurities such as endotoxins and nucleic acids, have a short half-life in human blood, and incur high production costs. Some medicinal proteins have been successfully expressed in plants and used in clinical applications, suggesting that plants may also be a good system for IFN expression. However, there are still many technical problems that need to be addressed before the clinical application of plant-expressed IFNs, such as increasing the amount of recombinant protein expression and ensuring that the IFN is modified with the correct type of glycosylation. In this article, we review the classification of IFNs, their roles in antiviral signal transduction pathways, their clinical applications, and their expression in plant systems.

Interferon Alpha, but Not Interferon Beta, Acts Early To Control Chronic Chikungunya Virus Pathogenesis

Chikungunya virus (CHIKV) is an arthritogenic alphavirus that causes both debilitating acute and chronic disease. Previous work has shown that type I interferons (IFNs) play a critical role in limiting CHIKV pathogenesis and that interferon alpha (IFN-α) and interferon beta (IFN-β) control acute CHIKV infection by distinct mechanisms. However, the role of type I IFNs, especially specific subtypes, during chronic CHIKV disease is unclear. To address this gap in knowledge, we evaluated chronic CHIKV pathogenesis in mice lacking IFN-α or IFN-β. We found that IFN-α was the dominant subtype that controls chronic disease. Despite detecting a varying type I IFN response throughout the course of disease, IFN-α acts within the first few days of infection to control the levels of persistent CHIKV RNA. In addition, using a novel CHIKV-3'-Cre tdTomato reporter system that fate maps CHIKV-infected cells, we showed that IFN-α limits the number of cells that survive CHIKV at sites of dissemination, particularly dermal fibroblasts and immune cells. Though myofibers play a significant role in CHIKV disease, they were not impacted by the loss of IFN-α. Our studies highlight that IFN-α and IFN-β play divergent roles during chronic CHIKV disease through events that occur early in infection and that not all cell types are equally dependent on type I IFNs for restricting viral persistence. IMPORTANCE Chikungunya virus (CHIKV) is a reemerging global pathogen with no effective vaccine or antiviral treatment for acute or chronic disease, and the mechanisms underlying chronic disease manifestations remain poorly defined. The significance of our research is in defining IFN-α, but not IFN-β, as an important host regulator of chronic CHIKV pathogenesis that acts within the first 48 hours of infection to limit persistent viral RNA and the number of cells that survive CHIKV infection 1 month post-infection. Loss of IFN-α had a greater impact on immune cells and dermal fibroblasts than myofibers, highlighting the need to delineate cell-specific responses to type I IFNs. Altogether, our work demonstrates that very early events of acute CHIKV infection influence chronic disease. Continued efforts to delineate early host-pathogen interactions may help stratify patients who are at risk for developing chronic CHIKV symptoms and identify therapeutics that may prevent progression to chronic disease altogether.

Interferon system deficiencies exacerbating severe pandemic virus infections

Pandemics are caused by novel pathogens to which pre-existing antibody immunity is lacking. Under these circumstances, the body must rely on innate interferon-mediated defenses to limit pathogen replication and allow development of critical humoral protection. Here, we highlight studies on disease susceptibility during H1N1 influenza and COVID-19 (SARS-CoV-2) pandemics. An emerging concept is that genetic and non-genetic deficiencies in interferon system components lead to uncontrolled virus replication and severe illness in a subset of people. Intriguingly, new findings suggest that individuals with autoantibodies neutralizing the antiviral function of interferon are at increased risk of severe COVID-19. We discuss key questions surrounding how such autoantibodies develop and function, as well as the general implications of diagnosing interferon deficiencies for personalized therapies.

A novel phosphoproteomic landscape evoked in response to type I interferon in the brain and in glial cells

BACKGROUND

Type I interferons (IFN-I) are key responders to central nervous system infection and injury and are also increased in common neurodegenerative diseases. Their effects are primarily mediated via transcriptional regulation of several hundred interferon-regulated genes. In addition, IFN-I activate several kinases including members of the MAPK and PI3K families. Yet, how changes to the global protein phosphoproteome contribute to the cellular response to IFN-I is unknown.

METHODS

The cerebral phosphoproteome of mice with brain-targeted chronic production of the IFN-I, IFN-α, was obtained. Changes in phosphorylation were analyzed by ontology and pathway analysis and kinase enrichment predictions. These were verified by phenotypic analysis, immunohistochemistry and immunoblots. In addition, primary murine microglia and astrocytes, the brain's primary IFN-I-responding cells, were acutely treated with IFN-α and the global phosphoproteome was similarly analyzed.

RESULTS

We identified widespread protein phosphorylation as a novel mechanism by which IFN-I mediate their effects. In our mouse model for IFN-I-induced neurodegeneration, protein phosphorylation, rather than the proteome, aligned with the clinical hallmarks and pathological outcome, including impaired development, motor dysfunction and seizures. In vitro experiments revealed extensive and rapid IFN-I-induced protein phosphorylation in microglia and astrocytes. Response to acute IFN-I stimulation was independent of gene expression and mediated by a small number of kinase families. The changes in the phosphoproteome affected a diverse range of cellular processes and functional analysis suggested that this response induced an immediate reactive state and prepared cells for subsequent transcriptional responses.

CONCLUSIONS

Our studies reveal a hitherto unappreciated role for changes in the protein phosphorylation landscape in cellular responses to IFN-I and thus provide insights for novel diagnostic and therapeutic strategies for neurological diseases caused by IFN-I.