Antitumor activity of pegylated human interferon ß as monotherapy or in combination with immune checkpoint inhibitors via tumor growth inhibition and dendritic cell activation.

Type I interferons (IFN), especially human IFN alpha (IFNα), have been utilized for antitumor therapy for decades. Human interferon beta (IFNß) is rarely used for cancer treatment, despite advantages over IFNα in biological activities such as tumor growth inhibition and dendritic cell (DC) activation. The utilization of pegylated human IFNß (PEG-IFNß), as monotherapy or in combination with immune checkpoint inhibitors (ICIs) was evaluated in this study through in vivo efficacy studies in syngeneic mouse melanoma, non-small cell lung cancer (NSCLC), and colon adenocarcinoma (COAD) models resistant to immune checkpoint inhibitors (ICIs). In vitro comparative study of PEG-IFNß and pegylated IFNα-2b was performed in terms of tumor growth inhibition against human melanoma, NSCLC and COAD cell lines and activation of human monocyte-derived DCs (MoDCs). Our data demonstrate that the in vivo antitumor effects of PEG-IFNß are partially attributable to tumor growth-inhibitory effects and DC-activating activities, superior to pegylated IFNα-2b. Our findings suggest that utilizing PEG-IFNß as an antitumor therapy can enhance the therapeutic effect of ICIs in ICI-resistant tumors by directly inhibiting tumor growth and induction of DC maturation.

Method for quantification of porcine type I interferon activity using luminescence, by direct and indirect means.

BACKGROUND: Type I interferons are widely used in research applications and as biotherapeutics. Current assays used to measure interferon concentrations, such as plaque reduction assays and ELISA, are expensive, technically challenging, and may take days to provide results. We sought to develop a robust and rapid assay to determine interferon concentrations produced from transiently transfected cell cultures. METHOD: Indirect quantification of recombinant interferon was evaluated using a novel bi-cistronic construct encoding the Foot-and-mouth disease virus 2A translational interrupter sequence to yield equimolar expression of Gaussia princeps luciferase and porcine interferon α. Direct quantification was evaluated by expression of a novel fusion protein comprised of Gaussia princeps luciferase and porcine type I interferon. Plasmids encoding constructs are transiently transfected into cell cultures and supernatant harvested for testing of luminescence, ELISA determined concentration, and anti-viral activity against vesicular stomatitis virus. RESULTS: Bi-cistronic constructs, utilized for indirect quantification, demonstrate both luciferase activity and anti-viral activity. Fusion proteins, utilized for direct quantification, retained secretion and luminescence however only the interferon α fusion protein had antiviral activity comparable to wildtype porcine interferon α. A strong linear correlation was observed between dilution and luminescence for all compounds over a dynamic range of concentrations. CONCLUSION: The correlation of antiviral and luciferase activities demonstrated the utility of this approach, both direct and indirect, to rapidly determine recombinant interferon concentrations. Concentration can be determined over a more dynamic concentration range than available ELISA based assays using this methodology.

Role of the Chaperone Protein 14-3-3ε in the Regulation of Influenza A Virus-Activated Beta Interferon.

The NS1 protein of the influenza A virus plays a critical role in regulating several biological processes in cells, including the type I interferon (IFN) response. We previously profiled the cellular factors that interact with the NS1 protein of influenza A virus and found that the NS1 protein interacts with proteins involved in RNA splicing/processing, cell cycle regulation, and protein targeting processes, including 14-3-3ε. Since 14-3-3ε plays an important role in retinoic acid-inducible gene I (RIG-I) translocation to mitochondrial antiviral-signaling protein (MAVS) to activate type I IFN expression, the interaction of the NS1 and 14-3-3ε proteins may prevent the RIG-I-mediated IFN response. In this study, we confirmed that the 14-3-3ε protein interacts with the N-terminal domain of the NS1 protein and that the NS1 protein inhibits RIG-I-mediated IFN-ß promoter activation in 14-3-3ε-overexpressing cells. In addition, our results showed that knocking down 14-3-3ε can reduce IFN-ß expression elicited by influenza A virus and enhance viral replication. Furthermore, we found that threonine in the 49th amino acid position of the NS1 protein plays a role in the interaction with 14-3-3ε. Influenza A virus expressing C terminus-truncated NS1 with a T49A mutation dramatically increases IFN-ß mRNA in infected cells and causes slower replication than that of virus without the T-to-A mutation. Collectively, this study demonstrates that 14-3-3ε is involved in influenza A virus-initiated IFN-ß expression and that the interaction of the NS1 protein and 14-3-3ε may be one of the mechanisms for inhibiting type I IFN activation during influenza A virus infection. IMPORTANCE Influenza A virus is an important human pathogen causing severe respiratory disease. The virus has evolved several strategies to dysregulate the innate immune response and facilitate its replication. We demonstrate that the NS1 protein of influenza A virus interacts with the cellular chaperone protein 14-3-3ε, which plays a critical role in retinoic acid-inducible gene I (RIG-I) translocation that induces type I interferon (IFN) expression, and that NS1 protein prevents RIG-I translocation to the mitochondrial membrane. The interaction site for 14-3-3ε is the RNA-binding domain (RBD) of the NS1 protein. Therefore, this research elucidates a novel mechanism by which the NS1 RBD mediates IFN-ß suppression to facilitate influenza A viral replication. Additionally, the findings reveal the antiviral role of 14-3-3ε during influenza A virus infection.

Interferon ß, an enhancer of the innate immune response against SARS-CoV-2 infection.

COVID-19 exhibits a global health threat among the elderly and the population with underlying health conditions. During infection, the host's innate immune response acts as a frontline of defense by releasing cytokines such as type I interferon (IFN α and ß) thereby initiating antiviral activity. However, this particular interferon response is interrupted by factors such as SARS-CoV-2 non-structural proteins, aging, diabetes, and germ-line errors eventually making the host more susceptible to illness. Therefore, enhancing the host's innate immune response by administering type I IFN could be an effective treatment against COVID-19. Here, we highlight the importance of innate immune response and the role of IFN ß monotherapy against COVID-19.

Evaluation of the Relationships between Intestinal Regional Lymph Nodes and Immune Responses in Viral Infections in Children.

Viral infections increase the risk of developing allergies in childhood, and disruption of mucosal homeostasis is presumed to be involved. However, no study has reported a role for viral infections in such disruption. In this study, we clarified the mechanism of immunoglobulin A (IgA) overproduction in viral infections. Autopsies were performed on 33 pediatric cases, IgA and interferon (IFN)ß levels were measured, and histopathological and immunohistochemical examinations were conducted. Furthermore, we cultured human cells and measured IFNß and IgA levels to examine the effect of viral infections on IgA production. Blood IgA levels in viral infections were higher than in bacterial infections. Moreover, IFNß levels in most viral cases were below the detection limit. Cell culture revealed increased IgA in gastrointestinal lymph nodes, especially in Peyer's patches, due to enhanced IFNß after viral stimulation. Conversely, respiratory regional lymph nodes showed enhanced IgA with no marked change in IFNß. Overproduction of IgA, identified as an aberration of the immune system and resulting from excessive viral infection-induced IFNß was observed in the intestinal regional lymph nodes, particularly in Peyer's patches. Further, increased IgA without elevated IFNß in the respiratory system suggested the possibility of a different mechanism from the gastrointestinal system.

Effects of interferon and glatiramer acetate on cytokine patterns in multiple sclerosis patients.

Multiple sclerosis (MS) is an unpredictable autoimmune disease, which causes neurodegeneration in the central nervous system. Since the main cause of MS remains obscure, in this study, we aimed to evaluate the serum levels of some cytokines, including interleukin-5 (IL-5), IL-8, IL-9, IL-17A, transforming growth factor-beta (TGF-ß), and interferon-gamma (IFN-γ) in relapsing-remitting (RR)-MS patients, treated with IFN-ß and glatiramer acetate (GA). Serum samples of RR-MS patients, treated with high-dose IFN-ß1a, low-dose IFN-ß1a, IFN-ß1b, and GA, were assessed by ELISA assay and then compared with the results of treatment-naive patients and healthy controls. The findings showed that the serum levels of IL-8, IL-9, and IFN-γ in treatment-naive patients were significantly higher than the healthy controls, while there was no significant difference in terms of other cytokines between the groups. A significant reduction was observed in the levels of IL-9 and IFN-γ, while there was a significant increase in TGF-ß level among patients treated with GA. IFN-ß1b resulted in a significant decline in the levels of IL-9 and TGF-ß. In addition to these findings, some cytokines were positively correlated in different groups. Overall, the present results support the inflammatory and aggravating effects of IL-8, IL-9, and IFN-γ on MS. Furthermore, based on the results reported in the GA treatment group, we suggest GA as an effective treatment for RR-MS patients.

Diminished stimulator of interferon genes production with cigarette smoke-exposure contributes to weakened anti-adenovirus vectors response and destruction of lung in chronic obstructive pulmonary disease model.

Cigarette smoke (CS) is the primary risk factor for chronic obstructive pulmonary disease (COPD) and dampens antiviral response, which increases viral infections and leads to COPD acute exacerbation (AECOPD). Adenovirus, a nonenveloped DNA virus, is linked with AECOPD, whose DNAs trigger innate immune response via interacting with pattern recognition receptors (PRRs). Stimulator of interferon genes (STING), as a cytosolic DNA sensor, participates in adenovirus-induced interferon ß (IFNß)-dependent antiviral response. STING is involved in various pulmonary diseases, but role of STING in pathogenesis of AECOPD is not well documented. In the present study, we explored relationship between STING and AECOPD induced by recombinant adenovirus vectors (rAdVs) and CS in wild type (WT) and STING-/- mice; and also characterized the inhibition of STING- IFNß pathway in pulmonary epithelium exposed to cigarette smoke extract (CSE). We found that CS or CSE exposure alone dramatically inhibited STING expression, but not significantly effected IFNß production. Moreover, CS or CSE-exposed significantly suppressed activation of STING-IFNß pathway induced by rAdVs and suppressed clearance of rAdVs DNA. Inflammation, fibrosis and emphysema of lung tissues were exaggerated when treated with CS plus rAdVs, which further deteriorate in absences of STING. In A549 cells with knockdown of STING, we also observed enhancing apoptosis related to emphysema, especially CSE and adenovirus vectors in combination. Therefore, STING may play a protective role in preventing the progress of COPD.

Interferon-Beta Treatment Differentially Alters TLR2 and TLR4-Dependent Cytokine Production in Multiple Sclerosis Patients.

OBJECTIVE: Multiple sclerosis (MS) is a multifactorial chronic disease that affects the central nervous system (CNS). Toll-like receptors (TLRs) play a central role in cytokine production after pathogen- and danger-associated molecular patterns (PAMPs and DAMPs) and contribute to CNS damage in MS patients. Here, we evaluated the effects of interferon (IFN)-ß treatment in TLR2 and TLR4-dependent cytokine production and mRNA expression in whole-blood cell cultures from MS patients. METHODS: We evaluated cytokine production by ELISA from whole-blood cell culture supernatants and mRNA expression by real-time polymerase chain reaction in peripheral blood mononuclear cells (PBMCs). RESULTS: In patients treated with IFN-ß, tumor necrosis factor (TNF)-α production after exposure to TLR2 agonist (Pam3Cys) was lower than in healthy controls and untreated MS patients. However, IFN-ß treatment had no significant effect on TNF-α production after TLR4 agonist (LPS) stimulation. On the other hand, interleukin (IL)-10 production was increased in TLR4- but not in TLR2-stimulated whole-blood cell culture from MS patients under IFN-ß treatment when compared to the controls. No differences in TNF-α or IL-10 mRNA expression in PBMCs from healthy controls and untreated or treated MS patients were detected, although PBMCs from treated patients presented higher levels of IL-32γ mRNA than those from controls. CONCLUSIONS: Our data suggest that IFN-ß treatment alters the TLR-dependent immune response of PBMCs from MS patients. This may contribute to the beneficial effects of IFN-ß treatment.

Production of IFNß by Conventional Dendritic Cells after Stimulation with Viral Compounds and IFNß-Independent IFNAR1-Signaling Pathways are Associated with Aggravation of Polymicrobial Sepsis.

Viral infections are associated with increased incidence of severe sepsis. Particularly during the early stages, type I interferons (IFNs) are known mediators of detrimental effects. However, the functional role of early interferon ß (IFNß) and its cellular source during sepsis in the context of preexisting viral infections has not been defined. Using the colon ascendens stent peritonitis (CASP) model, we demonstrate that IFNß-/- and type I IFN receptor (IFNAR1)-/- mice were less susceptible to sepsis after pre-stimulation with the viral mimetic poly(I:C). Wild type (WT) mice treated with poly(I:C) exhibited altered expression patterns of TNF and IL-12p40 during CASP which were dependent on IFNß or IFNAR1, suggesting a mechanism for the increased sepsis susceptibility of WT mice. Using a double cytokine reporter mouse model, we present novel data on the simultaneous expression of IFNß and IL-12p40 on a single cell level during polymicrobial sepsis in vivo. Conventional dendritic cells (cDCs) were identified as primary source of IFNß and the protective cytokine IL-12p40 after CASP surgery irrespective of poly(I:C) pre-stimulation. These data demonstrated that if polymicrobial sepsis is preceded by a viral infection, IFNß and IL-12p40 are expressed by polyfunctional cDCs suggesting that these cells can play both detrimental and beneficial roles during sepsis development.

Effectiveness of dimethyl fumarate as first line therapy in MS patients - one center real life observation study.

Interferon ß, glatiramer acetate and dimethyl fumarate are first line of disease-modifying therapies for patients who have got relapsingremitting multiple sclerosis (RRMS). Currently, there are no precise guidelines for modifying treatment. This is the individual decision of the attending physician, which should take into account both the clinical course of the disease and the patient's preferences. Therefore, possible findings of this study may potentially improve treatment strategy and could be helpful for the clinicians to select the most appropriate therapy. AIM: The aim of this study was to evaluate and compare activity of multiple sclerosis one year before and one year after switching treatment from interferon ß or glatiramer acetate to dimethyl fumarate. The reasons for treatment modification and impact of these reasons on therapy effectiveness were studied as a secondary outcome. MATERIALS AND METHODS: This observational and retrospective study among patients with RRMS lasted for 2 years and was conducted at one medical center. Participants of the study were aged 19-61 years. All of them had been initially treated with disease-modifying drugs (DMDs) by injection: interferon or glatiramer acetate. After one-year observation patients switched therapy to dimethyl fumarate (DMF) for various reasons. RESULTS: 62 adult patients received interferon beta or glatiramer acetate in the first year. After a year all of them switched from that therapy to dimethyl fumarate. Patients in all treatment groups had similar demographic and clinical characteristics at baseline. The most common reason for change in interferon ß group were adverse effects or clinical ineffectiveness. Patients from glatiramer acetate group most often changed their therapy due to new lesions on MRI scans. Presented study shows a statistically significant decrease in radiological relapse when changing treatment from glatiramer acetate to dimethyl fumarate. At the same time, switching from interferon to dimethyl fumarate reduced the number of clinical relapses. There was no statistically significant difference in EDSS scores before and after treatment change in interferons' ß and glatiramer acetate's groups. CONCLUSIONS: The results of our study show that patients with progression of the disease should be treated with another medication. Further research is necessary to develop therapeutic position that supports therapeutic decision in an early period of MS. The observation of the presented group of patients will be continued.

Protein kinase IKKß-catalyzed phosphorylation of IRF5 at Ser462 induces its dimerization and nuclear translocation in myeloid cells.

The siRNA knockdown of IFN Regulatory Factor 5 (IRF5) in the human plasmacytoid dendritic cell line Gen2.2 prevented IFNß production induced by compound CL097, a ligand for Toll-like receptor 7 (TLR7). CL097 also stimulated the phosphorylation of IRF5 at Ser462 and stimulated the nuclear translocation of wild-type IRF5, but not the IRF5[Ser462Ala] mutant. The CL097-stimulated phosphorylation of IRF5 at Ser462 and its nuclear translocation was prevented by the pharmacological inhibition of protein kinase IKKß or the siRNA knockdown of IKKß or its "upstream" activator, the protein kinase TAK1. Similar results were obtained in a murine macrophage cell line stimulated with the TLR7 agonist compound R848 or the nucleotide oligomerization domain 1 (NOD1) agonist KF-1B. IKKß phosphorylated IRF5 at Ser462 in vitro and induced the dimerization of wild-type IRF5 but not the IRF5[S462A] mutant. These findings demonstrate that IKKß activates two "master" transcription factors of the innate immune system, IRF5 and NF-κB.

Toll-Like Receptor 3 and Interferon ß mRNA Expressions Were Increased in Peripheral Blood of Ischemic Stroke Patients with Good Outcome.

BACKGROUND: Innate immunity plays an important role in brain ischemic injury, but there are only few studies on the effects of toll-like receptors (TLRs) on cerebral infarction patients up to now. We aimed to evaluate the TLR mRNA expression of patients with different outcomes. METHODS: Eighty-six cases suffering from cerebral infarction within 14 days were assigned into the good outcome group (n = 47) and the bad outcome group (n = 39) depending on the modified Rankin Scale scores (mRS ≤2 at 90 days following stroke onset was good outcome). We measured the mRNA expression of TLRs in peripheral blood mononuclear cells of patients at 24 hours, 3 days, 4 days, 7 days, and 14 days from onset. The National Institutes of Health Stroke Scale score and infarction volume were assessed on admission and at 7-14 days, respectively. RESULTS: Only TLR3 mRNA expression of the good outcome group was higher than that of the bad outcome group at acute and subacute phases. TLR7 expressions of the good outcome group increased within 3 days following stroke onset. Moreover, the two groups had no significant differences in terms of mRNA expressions of TLR2, TLR4, TLR8, and TLR9. The expression of interferon ß of the good outcome group was higher than that of the bad outcome group, and it had a positive correlation with the expressions of TLR3 and interferon regulatory factor 3. CONCLUSIONS: TLR3 and interferon ß mRNA expressions were increased in the peripheral blood of ischemic stroke patients with good outcome, which may imply their neuroprotection.

Minocycline added to subcutaneous interferon ß-1a in multiple sclerosis: randomized RECYCLINE study.

BACKGROUND AND PURPOSE: Combining different therapies may improve disease control in patients with relapsing-remitting multiple sclerosis (RRMS). This study assessed the efficacy and safety of minocycline added to subcutaneous (sc) interferon (IFN) ß-1a therapy. METHODS: This was a double-blind, randomized, placebo-controlled multicentre study. Within 3 months (±1 month) of starting sc IFN ß-1a 44 µg three times weekly, patients with RRMS were randomized to minocycline 100 mg twice daily or placebo, added to sc IFN ß-1a, for 96 weeks. The primary efficacy endpoint was the time to first qualifying relapse. Secondary efficacy endpoints were the annualized relapse rate for qualifying relapses, the number of new/enlarging T2-weighted lesions and change in brain volume [magnetic resonance imaging (MRI) was performed only in a few selected centres]. In addition, a number of tertiary efficacy endpoints were assessed. RESULTS: One hundred and forty-nine patients received minocycline and 155 received placebo; MRI data were available for 23 and 27 patients, respectively. The time to first qualifying relapse did not differ significantly for minocycline versus placebo (hazard ratio 0.85; 95% confidence interval 0.53, 1.35; log-rank = 0.50; P = 0.48). There were no statistically significant differences between the two groups on other efficacy endpoints, although some numerical trends in favour of minocycline were observed. No unexpected adverse events were reported, but more patients discontinued because of adverse events with minocycline versus placebo. CONCLUSION: Minocycline showed no statistically significant beneficial effect when added to sc IFN ß-1a therapy.

Acute liver failure and liver transplantation in a patient with multiple sclerosis treated with interferon beta.

In the treatment of multiple sclerosis (MS), interferon beta (IFNß) applies. It rarely can lead to acute liver failure (ALF). A 42-year-old female with MS was admitted to the Department because of jaundice, general weakness, drowsiness and nausea. Four weeks earlier, she had started therapy with IFNß-1a. Liver tests made prior to initiation of IFNß-1a were normal but on admission to the Department exceed several times the upper limit. ALF was recognized and IFNß-1a was immediately stopped. In the fourth day of hospitalization, symptoms of hepatic encephalopathy have progressed. The patient was transferred to the Department of Transplantation, where hepatic coma developed and three days later the orthotopic liver transplantation was performed. In histopathological picture of the removed liver extensive necrosis and fibrosis dominated. Immunosuppressive therapy consisted of tacrolimus, mycophenolate mofetil and tapering prednisone. Within five years after surgery, there was no recurrence of symptoms of MS and the transplanted organ is functioning properly. ALF is a rare complication of IFNß therapy but it can occur. The appearance of symptoms suggestive of liver injury should prompt extension of diagnosis and, if necessary, discontinuation of therapy.

Conserved Antagonization of Type I Interferon Signaling by Arterivirus GP5 Proteins.

Arteriviruses can establish persistent infections in animals such as equids, pigs, nonhuman primates, rodents, and possums. Some Arteriviruses can even cause overt and severe diseases such as Equine Arteritis in horses and Porcine Reproductive and Respiratory Syndrome in pigs, leading to huge economic losses. Arteriviruses have evolved viral proteins to antagonize the host cell's innate immune responses by inhibiting type I interferon (IFN) signaling, assisting viral evasion and persistent infection. So far, the role of the Arterivirus glycoprotein 5 (GP5) protein in IFN signaling inhibition remains unclear. Here, we investigated the inhibitory activity of 47 Arterivirus GP5 proteins derived from various hosts. We demonstrated that all GP5 proteins showed conserved activity for antagonizing TIR-domain-containing adapter proteins inducing interferon-ß (TRIF)-mediated IFN-ß signaling through TRIF degradation. In addition, Arterivirus GP5 proteins showed a conserved inhibitory activity against IFN-ß signaling, induced by either pig or human TRIF. Furthermore, certain Arterivirus GP5 proteins could inhibit the induction of IFN-stimulated genes. These findings highlight the role of Arterivirus GP5 proteins in supporting persistent infection.

Chromosomal radiosensitivity in patients with multiple sclerosis.

Multiple sclerosis is a clinically heterogeneous autoimmune disease leading to severe neurological disability. Although during the last years many disease-modifying agents as treatment options for multiple sclerosis have been made available, their mechanisms of action are still not fully determined. In the present study radiosensitivity in lymphocytes of patients with relapsing-remitting multiple sclerosis, secondary progressive multiple sclerosis and healthy controls was investigated. Whole blood cultures from multiple sclerosis patients and healthy controls were used to analyze the spontaneous and radiation-induced micronuclei in binucleated lymphocytes. A subgroup of patients with relapsing-remitting multiple sclerosis was treated with immunomodulatory agents, interferon ß or glatiramer acetate. The secondary progressive multiple sclerosis patients group was not receiving any treatment. Our results reveal that the basal DNA damage was not different between relapsing-remitting and secondary progressive multiple sclerosis patients, and healthy controls. No differences between gamma-irradiation induced micronuclei frequencies in binucleated cells from relapsing-remitting and secondary progressive multiple sclerosis patients, and healthy controls were found either. Nevertheless, when we compared the radiation induced DNA damage in binucleated cells from healthy individuals with the whole group of patients, a reduction in the frequency of micronuclei was obtained in the patients group. Induced micronuclei yield was significantly lower in the irradiated samples from treated relapsing-remitting multiple sclerosis patients than in healthy controls and relapsing-remitting not treated patients. Intrinsic sensitivity of lymphocytes subpopulations to the apoptotic effect of immunomodulatory treatment could be responsible for this result.

The value of Interferon ß in multiple sclerosis and novel opportunities for its anti-viral activity: a narrative literature review.

Interferon-beta (IFN-ß) for Multiple Sclerosis (MS) is turning 30. The COVID-19 pandemic rejuvenated the interest in interferon biology in health and disease, opening translational opportunities beyond neuroinflammation. The antiviral properties of this molecule are in accord with the hypothesis of a viral etiology of MS, for which a credible culprit has been identified in the Epstein-Barr Virus. Likely, IFNs are crucial in the acute phase of SARS-CoV-2 infection, as demonstrated by inherited and acquired impairments of the interferon response that predispose to a severe COVID-19 course. Accordingly, IFN-ß exerted protection against SARS-CoV-2 in people with MS (pwMS). In this viewpoint, we summarize the evidence on IFN-ß mechanisms of action in MS with a focus on its antiviral properties, especially against EBV. We synopsize the role of IFNs in COVID-19 and the opportunities and challenges of IFN-ß usage for this condition. Finally, we leverage the lessons learned in the pandemic to suggest a role of IFN-ß in long-COVID-19 and in special MS subpopulations.

Dexamethasone impairs the expression of antimicrobial mediators in lipopolysaccharide-activated primary macrophages by inhibiting both expression and function of interferon ß.

Glucocorticoids potently inhibit expression of many inflammatory mediators, and have been widely used to treat both acute and chronic inflammatory diseases for more than seventy years. However, they can have several unwanted effects, amongst which immunosuppression is one of the most common. Here we used microarrays and proteomic approaches to characterise the effect of dexamethasone (a synthetic glucocorticoid) on the responses of primary mouse macrophages to a potent pro-inflammatory agonist, lipopolysaccharide (LPS). Gene ontology analysis revealed that dexamethasone strongly impaired the lipopolysaccharide-induced antimicrobial response, which is thought to be driven by an autocrine feedback loop involving the type I interferon IFNß. Indeed, dexamethasone strongly and dose-dependently inhibited the expression of IFNß by LPS-activated macrophages. Unbiased proteomic data also revealed an inhibitory effect of dexamethasone on the IFNß-dependent program of gene expression, with strong down-regulation of several interferon-induced antimicrobial factors. Surprisingly, dexamethasone also inhibited the expression of several antimicrobial genes in response to direct stimulation of macrophages with IFNß. We tested a number of hypotheses based on previous publications, but found that no single mechanism could account for more than a small fraction of the broad suppressive impact of dexamethasone on macrophage type I interferon signaling, underlining the complexity of this pathway. Preliminary experiments indicated that dexamethasone exerted similar inhibitory effects on primary human monocyte-derived or alveolar macrophages.

Small cytosolic double-stranded DNA represses cyclic GMP-AMP synthase activation and induces autophagy.

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway is a major mediator of inflammation following stimulation with >45 bp double-stranded DNA (dsDNA). Herein, we identify a class of ∼20-40 bp small cytosolic dsDNA (scDNA) molecules that compete with long dsDNA (200-1,500 bp herring testis [HT]-DNA) for binding to cGAS, thus repressing HT-DNA-induced cGAS activation. The scDNA promotes cGAS and Beclin-1 interaction, releasing Rubicon, a negative regulator of phosphatidylinositol 3-kinase class III (PI3KC3), from the Beclin-1-PI3KC3 complex. This leads to PI3KC3 activation and induces autophagy, causing degradation of STING and long cytosolic dsDNA. Moreover, DNA damage decreases, and autophagy inducers increase scDNA levels. scDNA transfection and treatment with autophagy inducers attenuate DNA damage-induced cGAS activation. Thus, scDNA molecules serve as effective brakes for cGAS activation, preventing excessive inflammatory cytokine production following DNA damage. Our findings may have therapeutic implications for cytosolic DNA-associated inflammatory diseases.

Predictive value of number and volume of demyelinating plaques in treatment response in patients with multiple sclerosis treated with INF-B.

BACKGROUND: Multiple Sclerosis (MS) is an autoimmune, inflammatory disease of the central nervous system. Magnetic resonance imaging (MRI) findings are associated with disease clinical activity and response to treatment. This study aimed to evaluate the future value of plaque number and volume in MRI as radiological criteria in determining the treatment response to INF-B in patients with MS. METHODS: This is a cross-sectional study performed in 2016-2021 in Iran on patients with the newly diagnosed (less than one year) relapsing-remitting MS. Brain MRI was taken for all patients. The number and volumes of the MS plaques were evaluated from FLAIR images by the two radiologists. Patients were treated with INF-B1a with a dosage of 12 million units equal to 44 micrograms subcutaneously, three times per week. Patients were visited monthly by neurologists to examine their clinical status. After one year, the brain MRI was conducted with the similar characteristics to the beginning of the study, and the number and volume of MS plaques were measured again. RESULTS: The study population consisted of 33 males and 90 females with a mean age of 28.37 ± 6.29 years. The mean Expanded Disability Status Scale (EDSS) of the patients was 3.16 ± 0.23 at the beginning of the study. The specificity for a 50% reduction in the number and volume of plaques as two separate criteria was the same and equal to 100%. The sensitivity of the number and volume of plaques were 65.5% and 90.6%, respectively. In addition, considering 10% as the cut-off point of the number of plaques, the sensitivity of the number of plaques as a criterion was equal to the sensitivity of the plaque volume. CONCLUSION: The results of this study showed that imaging criteria provide a more objective tool for evaluating the effectiveness of treatment. These findings indicate that the number and volume of plaques could be two reliable MRI imaging criteria for assessing therapy response. The number of plaques was less accurate than the volume of plaques.