Type I IFN family members: similarity, differences and interaction

The role of interferon beta in neurological diseases and its potential therapeutic relevance

Interferon beta (IFNβ) is a member of the type-1 interferon family and has various immunomodulatory functions in neuropathological conditions. Although the level of IFNβ is low under healthy conditions, it is increased during inflammatory processes to protect the central nervous system (CNS). In particular, microglia and astrocytes are the main sources of IFNβ upon inflammatory insult in the CNS. The protective effects of IFNβ are well characterized in reducing the progression of multiple sclerosis (MS); however, little is understood about its effects in other neurological/neurodegenerative diseases. In this review, different types of IFNs and their signaling pathways will be described. Then we will focus on the potential role and therapeutic effect of IFNβ in several CNS-related diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, stroke, spinal cord injury, prion disease and spinocerebellar ataxia 7.

Macleaya cordata extract improves egg quality by altering gut health and microbiota in laying hens

This study investigated the effect of Macleaya cordata extract (MCE) on the performance, gut health, and microbiota of laying hens. A total of 192 thirty-wk-old Hyline brown laying hens were randomly divided into 4 treatment groups. The CON group received a basal diet, while the low (MCE250), medium (MCE350), and high (MCE450) dose groups were supplemented with 250, 350, and 450 mg/kg MCE, respectively. The egg weight and Haugh unit demonstrated a linear and quadratic increase with the MCE dose during the initial 4-wk period of the experiment (P < 0.05). Furthermore, the dietary supplementation of MCE led to a significant enhancement in eggshell thickness and Haugh unit at wk 8 and the data showed a statistically significant linear and quadratic increase (P < 0.05). Serum cytokine assay showed that dietary supplementation of MCE led to linear and quadratic increases in IL-4 and IL-10 level (P < 0.05). Dietary supplementation of 350 and 450 mg/kg MCE was observed to result in linear and quadratic increase in serum lysozyme levels (P < 0.05). The addition of MCE to the diet resulted in a linear and quadratic increase in the levels of sIgA in the jejunum and ileum (P < 0.05). In terms of gene expression, the addition of MCE to the diet resulted in linear and quadratic increases in the expression of IL-10, IgA, Serpinb14, Serpinb14B, and OIH (P < 0.05). The expression of jejunal genes pIgR and IL-4 was observed to increase in a linear and quadratic manner, respectively, following the dietary addition of 350 mg/kg MCE and IL-1β decreased in a linear manner (P < 0.05). Moreover, these favorable effects were maximized at medium dosage (350 mg/kg) of MCE addition, and intestinal microbial composition in the control and MCE350 groups was assessed. 350 mg/kg MCE increased the relative abundance of Bryobacter and Parasutterella and decreased the relative abundance of Erysipelatoclostridium in the cecum (P < 0.05). Spearman correlation analysis revealed that Bryobacter, Parasutterella, Skermanella, and Erysipelatoclostridium were associated with nonspecific immune functions (P < 0.05). In conclusion, 350 mg/kg MCE supplementation elevated the immune response, and upregulated the expression of genes related to protein production in eggs, thereby improving egg quality. These effects may be associated with changes in the microbiota, specifically Bryobacter, Parasutterella, and Erysipelatoclostridium.

Research progress on interferon and cellular senescence

Since the 12 major signs of aging were revealed in 2023, people's interpretation of aging will go further, which is of great significance for understanding the occurrence, development, and intervention in the aging process. As one of the 12 major signs of aging, cellular senescence refers to the process in which the proliferation and differentiation ability of cells decrease under stress stimulation or over time, often manifested as changes in cell morphology, cell cycle arrest, and decreased metabolic function. Interferon (IFN), as a secreted ligand for specific cell surface receptors, can trigger the transcription of interferon-stimulated genes (ISGs) and play an important role in cellular senescence. In addition, IFN serves as an important component of SASP, and the activation of the IFN signaling pathway has been shown to contribute to cell apoptosis and senescence. It is expected to delay cellular senescence by linking IFN with cellular senescence and studying the effects of IFN on cellular senescence and its mechanism. This article provides a review of the research on the relationship between IFN and cellular senescence by consulting relevant literature.

Interferon-I modulation and natural products: Unraveling mechanisms and therapeutic potential in severe COVID-19

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to pose a significant global public health threat, particularly to older adults, pregnant women, and individuals with underlying chronic conditions. Dysregulated immune responses to SARS-CoV-2 infection are believed to contribute to the progression of COVID-19 in severe cases. Previous studies indicates that a deficiency in type I interferon (IFN-I) immunity accounts for approximately 15 %-20 % of patients with severe pneumonia caused by COVID-19, highlighting the potential therapeutic importance of modulating IFN-I signals. Natural products and their derivatives, due to their structural diversity and novel scaffolds, play a crucial role in drug discovery. Some of these natural products targeting IFN-I have demonstrated applications in infectious diseases and inflammatory conditions. However, the immunomodulatory potential of IFN-I in critical COVID-19 pneumonia and the natural compounds regulating the related signal pathway remain not fully understood. In this review, we offer a comprehensive assessment of the association between IFN-I and severe COVID-19, exploring its mechanisms and integrating information on natural compounds effective for IFN-I regulation. Focusing on the primary targets of IFN-I, we also summarize the regulatory mechanisms of natural products, their impact on IFNs, and their therapeutic roles in viral infections. Collectively, by synthesizing these findings, our goal is to provide a valuable reference for future research and to inspire innovative treatment strategies for COVID-19.

The JAK-STAT pathway: from structural biology to cytokine engineering

The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway serves as a paradigm for signal transduction from the extracellular environment to the nucleus. It plays a pivotal role in physiological functions, such as hematopoiesis, immune balance, tissue homeostasis, and surveillance against tumors. Dysregulation of this pathway may lead to various disease conditions such as immune deficiencies, autoimmune diseases, hematologic disorders, and cancer. Due to its critical role in maintaining human health and involvement in disease, extensive studies have been conducted on this pathway, ranging from basic research to medical applications. Advances in the structural biology of this pathway have enabled us to gain insights into how the signaling cascade operates at the molecular level, laying the groundwork for therapeutic development targeting this pathway. Various strategies have been developed to restore its normal function, with promising therapeutic potential. Enhanced comprehension of these molecular mechanisms, combined with advances in protein engineering methodologies, has allowed us to engineer cytokines with tailored properties for targeted therapeutic applications, thereby enhancing their efficiency and safety. In this review, we outline the structural basis that governs key nodes in this pathway, offering a comprehensive overview of the signal transduction process. Furthermore, we explore recent advances in cytokine engineering for therapeutic development in this pathway.

Combined effect and mechanism of microplastic with different particle sizes and levofloxacin on developing Rana nigromaculata: Insights from thyroid axis regulation and immune system

Microplastics (MPs) usually appear in the aquatic environment as complex pollutants with other environmental pollutants, such as levofloxacin (LVFX). After 45-day exposure to LVFX and MPs with different particle sizes at environmental levels, we measured the weight, snout-to-vent length (SVL), and development stages of Rana nigromaculata. Furthermore, we analyzed proteins and genes related to immune system and thyroid axis regulation, intestinal histological, and bioaccumulation of LVFX and MPs in the intestine and brain to further explore the toxic mechanism of co-exposure. We found MPs exacerbated the effect of LVFX on growth and development, and the order of inhibitory effects is as follows: LVFX-MP3>LVFX-MP1>LVFX-MP2. 0.1 and 1 μm MP could penetrate the blood-brain barrier, interact with LVFX in the brain, and affect growth and development by regulating thyroid axis. Besides, LVFX with MPs caused severer interference on thyroid axis compared with LVFX alone. However, 10 μm MP was prone to accumulating in the intestine, causing severe histopathological changes, interfering with the intestinal immune system and influencing growth and development through immune enzyme activity. Thus, we concluded that MPs could regulate the thyroid axis by interfering with the intestinal immune system.

Assessment of serum inflammatory parameters in RRMS and SPMS patients

OBJECTIVES

Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease. Patients with relapsing-remitting MS (RRMS) and secondary progressive MS (SPMS) differ in their responses to treatment; therefore, the correct diagnosis of the particular type of MS is crucial, and biomarkers that can differentiate between the forms of MS need to be identified. The aim of this study was to compare the levels of inflammatory parameters in serum samples from patients with RRMS and SPMS.

METHODS

The study group consisted of 60 patients with diagnosed MS. The patients were divided into RRMS and SPMS groups. In the RRMS patients, the usage of disease-modifying treatment was included in our analysis. The serum levels of inflammatory parameters were evaluated.

RESULTS

The serum levels of BAFF, gp130 and osteopontin were significantly higher in SPMS patients than in RRMS patients. The serum levels of BAFF correlated with age in both RRMS and SPMS patients. The serum levels of MMP-2 were significantly higher in RRMS patients than in SPMS patients and correlated with the number of past relapses. The serum levels of IL-32 were significantly higher in RRMS treatment-naïve patients than in RRMS patients treated with disease-modifying therapy.

DISCUSSION

Significant differences were found in BAFF, gp130, MMP-2 and osteopontin levels between RRMS and SPMS patients. Serum IL-32 levels were statistically lower in RRMS patients treated with disease-modifying therapy than in treatment-naïve patients.

VRK1 promotes DNA-induced type I interferon production

BACKGROUND

Type I interferons (IFNs) are an essential class of cytokines with antitumor, antiviral and immunoregulatory effects. However, over-productive the type I IFNs are tightly associated with autoimmune disorders. Thus, the induction of type I interferons is precisely regulated to maintain immune hemostasis. This study aimed to identify a novel regulator of type I interferon signaling.

METHODS AND RESULTS

Primary BMDMs, isolated from mice, and human cell lines (HEK293 cells, Hela cells) and murine cell line (MEF cells) were cultured to generate in vitro models. After knockdown VRK1, real-time PCR and dual-luciferase reporter assay were performed to determine the expression level of the type I IFNs and ISGs following HTDNA and Poly (dA:dT) stimulation. Additionally, cells were treated with the VRK1 inhibitor, and the impact of VRK1 inhibition was detected. Upon HTDNA and Poly (dA:dT) stimulation, knockdown of VRK1 attenuated the induction of the type I IFNs and ISGs. Consistently, VRK-IN-1, a potent and selective VRK1 inhibitor, significantly suppressed the induction of the type I IFNs and ISGs in human and murine cell lines. Further, VRK-IN-1 inhibited induction of the type I IFNs in mouse primary BMDMs. Intriguingly, VRK1 potentiated the cGAS-STING- IFN-I axis response at STING level.

CONCLUSIONS

Our study reveals a novel function of VRK1 in regulating the production of type I IFNs. VRK-IN-1 might be a potential lead compound for suppressing aberrant type I IFNs in autoimmune disorders.

cGAS-STING and PD1/PDL-1 pathway in breast cancer: a window to new therapies

Breast cancer is a complex malignancy with diverse molecular and cellular subtypes and clinical outcomes. Despite advances in treatment, breast cancer remains a significant health challenge. However, recent advances in cancer immunotherapy have shown promising results in the treatment of breast cancer, particularly the use of inhibitors that target the immune checkpoint PD1/PDL1. Also, the cGAS-STING pathway, an important part of the innate immune response, has been considered as a major potential therapeutic target for breast cancer. In this narrative review, we provide an overview of the cGAS-STING and PD1/PDL-1 pathway in breast cancer, including their role in tumor development, progression, and response to treatment. We also discuss potential future directions for research.

In Vitro and In Vivo Crosstalk between Type I IFN and IL-8 Responses in SARS-CoV-2 Infection

COVID-19 patients show characteristic over-expression of different cytokines that may interfere with the interferon (IFN) response, delaying its production. Within the overexpressed cytokines, IL-8 plays a key role, and it may impede IFN-I activation. PBMC from eight healthy donors were exposed to 2019-nCoV/Italy-INMI1 isolate and supernatants/cells were collected at different time points; the production of either IFN-alpha or IL-8 was assessed. The same analysis was performed on plasma samples obtained from 87 COVID-19 patients. Antagonism between IFN-alpha and IL-8 was observed, since in those PBMC with medium or high IL-8 levels, IFN-α levels were low. The same scenario was observed in SARS-CoV-2-infected patients that were divided into three groups based on IL-8 low, medium and high levels; the correlation between low levels of IFN-α and high levels of IL-8 was statistically significant in both the IL-8 medium and IL-8 high group. Overall, our results showed a crosstalk/antagonism between IL-8 and IFN-alpha in PBMC from healthy donors challenged with SARS-CoV-2 and inversely proportional IFN-alpha levels to IL-8 concentrations detected in plasma samples from COVID-19 patients, suggesting that the impairment of the innate immune response in COVID-19 patients may be linked to a dysregulated cytokine response, namely through IL-8 production.

The role and application of three IFN-related reactions in psoriasis

The pathophysiology of psoriasis is a highly complicated one. Due to the disease's specificity, it not only affects the patient's skin negatively but also manifests systemic pathological changes. These clinical symptoms seriously harm the patient's physical and mental health. IFN, a common immunomodulatory factor, has been increasingly demonstrated to have a significant role in the development of psoriatic skin disease. Psoriasis is connected with a variety of immunological responses. New targets for the therapy of autoimmune skin diseases may emerge from further research on the mechanics of the associated IFN upstream and downstream pathways. Different forms of IFNs do not behave in the same manner in psoriasis, and understanding how different types of IFNs are involved in psoriasis may provide a better notion for future research. This review focuses on the involvement of three types of IFNs in psoriasis and related therapeutic investigations, briefly describing the three IFNs' production and signaling, as well as the dual effects of IFNs on the skin. It is intended that it would serve as a model for future research.

The jigsaw puzzle of pedigree: whole-genome resequencing reveals genetic diversity and ancestral lineage in Sunong black pigs

The Sunong black pig is a new composite breed under development generated from Chinese indigenous pig breeds (i.e., Taihu and Huai) and intensive pig breeds (i.e., Landrace and Berkshire), which is an important genetic material for studying breeding mechanisms. However, there is currently limited knowledge about the genetic structure and germplasm characteristics of Sunong black pigs. To comprehensively understand their genetic composition and ancestry proportions, we performed population structure and local ancestry inference analysis based on whole-genome sequencing information. The results showed that Sunong black pigs could be clustered independently into a group, whose pedigree was intermediate between indigenous and commercial pig breeds, but closer to commercial pigs. Furthermore, local ancestry inference analysis revealed that Sunong black pigs inherited immune and reproductive traits from indigenous pig breeds, including CC and CXC chemokine family, Toll-like receptor family, IFN gene family, ESR1, AREG and EREG gene, while growth and development-related traits were inherited from commercial pig breeds, including IGF1 and GSY2 gene. Overall, Sunong black pigs have formed a relatively stable genome structure with some advantageous traits inherited from their ancestral breeds. This study deepened the understanding of the breeding mechanism of Sunong black pigs and provided a reference for cross-breeding programmes in livestock.

Enterovirus D68 infection upregulates SOCS3 expression to inhibit JAK-STAT3 signaling and antagonize the innate interferon response of the host

Enterovirus D68 (EV-D68) can cause respiratory diseases and acute flaccid paralysis, posing a great threat to public health. Interferons are cytokines secreted by host cells that have broad-spectrum antiviral effects, inducing the expression of hundreds of interferon-stimulated genes (ISGs). EV-D68 activates ISG expression early in infection, but at a later stage, the virus suppresses ISG expression, a strategy evolved by EV-D68 to antagonize interferons. Here, we explore a host protein, suppressor of cytokine signaling 3 (SOCS3), is upregulated during EV-D68 infection and antagonizes the antiviral effects of type I interferon. We subsequently demonstrate that the structural protein of EV-D68 upregulated the expression of RFX7, a transcriptional regulator of SOCS3, leading to the upregulation of SOCS3 expression. Further exploration revealed that SOCS3 plays its role by inhibiting the phosphorylation of signal transducer and activator of transcription 3 (STAT3). The expression of SOCS3 inhibited the expression of ISG, thereby inhibiting the antiviral effect of type I interferon and promoting EV-D68 transcription, protein production, and viral titer. Notably, a truncated SOCS3, generated by deleting the kinase inhibitory region (KIR) domain, failed to promote replication and translation of EV-D68. Based on the above studies, we designed a short peptide named SOCS3 inhibitor, which can specifically bind and inhibit the KIR structural domain of SOCS3, significantly reducing the RNA and protein levels of EV-D68. In summary, our results demonstrated a novel mechanism by which EV-D68 inhibits ISG transcription and antagonizes the antiviral responses of host type I interferon.

IFN-α induced systemic lupus erythematosus complicated with hemophagocytic lymphohistiocytosis: a case report and literature review

Hemophagocytic lymphohistiocytosis (HLH) is a severe and life-threatening hyperinflammatory condition characterized by excessive activation of macrophages and T cells and resulted in multi-organ dysfunction. HLH can be a primary disease or secondary to infections, malignancy, and some autoimmune diseases, including adult-onset Still's disease (AOSD) and systemic lupus erythematosus (SLE). However, it is rare for HLH to occur as a secondary condition to drug-induced lupus erythematosus (DILE). In this report, we present a case of HLH as an unusual complication during SLE treatment in a 31-year-old male patient. The patient initially suffered from active chronic hepatitis B (CHB) and was treated with pegylated INFα-2b (Peg-INFα-2b), tenofovir disoproxil and lamivudine. After 19 months, CHB obtained biochemical and virological response with HBsAg positive to HBsAb. The patient developed fever, headache, and cytopenia after Peg-INFα-2b treatment for 33 months, and laboratory studies revealed that ANA and anti dsDNA were positive. He displayed 5 features meeting the HLH-2004 criteria for diagnosis including fever, pancytopenia, hyperferritinemia, high levels of soluble CD25, and hemophagocytosis on bone marrow biopsy. The patient was initiated with a combination treatment of intravenous methylprednisolone pulse therapy, oral cyclosporine, and etoposide (VP-16), which was followed by a course of oral prednisolone, intravenous cyclophosphamide pulse therapy, and entecavir with complete response. To our knowledge, this is the first report of IFN-α induced SLE complicating with HLH. Physicians should consider the potential autoimmune side effects of IFN-α therapy and be alert to insidious HLH in patients diagnosed with SLE.

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.

Inactive disease in patients with lupus is linked to autoantibodies to type I interferons that normalize blood IFNα and B cell subsets

Systemic lupus erythematosus (SLE) is characterized by increased expression of type I interferon (IFN)-regulated genes in 50%-75% of patients. We report that out of 501 patients with SLE analyzed, 73 (14%) present autoantibodies against IFNα (anti-IFN-Abs). The presence of neutralizing-anti-IFN-Abs in 4.2% of patients inversely correlates with low circulating IFNα protein levels, inhibition of IFN-I downstream gene signatures, and inactive global disease score. Hallmarks of SLE pathogenesis, including increased immature, double-negative plasmablast B cell populations and reduction in regulatory B cell (Breg) frequencies, were normalized in patients with neutralizing anti-IFN-Abs compared with other patient groups. Immunoglobulin G (IgG) purified from sera of patients with SLE with neutralizing anti-IFN-Abs impedes CpGC-driven IFNα-dependent differentiation of B cells into immature B cells and plasmablasts, thus recapitulating the neutralizing effect of anti-IFN-Abs on B cell differentiation in vitro. Our findings highlight a role for neutralizing anti-IFN-Abs in controlling SLE pathogenesis and support the use of IFN-targeting therapies in patients with SLE lacking neutralizing-anti-IFN-Abs.

An Aggrephagy-Related LncRNA Signature for the Prognosis of Pancreatic Adenocarcinoma

Pancreatic adenocarcinoma (PAAD) is a common, highly malignant, and aggressive gastrointestinal tumor. The conventional treatment of PAAD shows poor results, and patients have poor prognosis. The synthesis and degradation of proteins are essential for the occurrence and development of tumors. Aggrephagy is a type of autophagy that selectively degrades aggregated proteins. It decreases the formation of aggregates by degrading proteins, thus reducing the harm to cells. By breaking down proteins, it decreases the formation of aggregates; thus, minimizing damage to cells. For evaluating the response to immunotherapy and prognosis in PAAD patients, in this study, we developed a reliable signature based on aggrephagy-related genes (ARGs). We obtained 298 AGGLncRNAs. Based on the results of one-way Cox and LASSO analyses, the lncRNA signature was constructed. In the risk model, the prognosis of patients in the low-risk group was noticeably better than that of the patients in the high-risk group. Additionally, the ROC curves and nomograms validated the capacity of the risk model to predict the prognosis of PAAD. The patients in the low-risk and high-risk groups showed considerable variations in functional enrichment and immunological analysis. Regarding drug sensitivity, the low-risk and high-risk groups had different half-maximal inhibitory concentrations (IC50).

Immunomodulatory activity of manganese dioxide nanoparticles: Promising for novel vaccines and immunotherapeutics

Manganese (Mn), a nutrient inorganic trace element, is necessary for a variety of physiological processes of animal body due to their important roles in oxidative regulation effects and other aspects of activities. Moreover, manganese ion (Mn²⁺) has widely reported to be crucial for the regulations of different immunological responses, thus showing promising application as potential adjuvants and immunotherapeutics. Taking the advantages of Mn-based biological and immunological activities, Manganese dioxide nanoparticles (MnO₂ NPs) are a new type of inorganic nanomaterials with numerous advantages, including simple preparation, low cost, environmental friendliness, low toxicity, biodegradable metabolism and high bioavailability. MnO₂ NPs, as a kind of drug carrier, have also shown the ability to catalyze hydrogen peroxide (H₂O₂) to produce oxygen (O₂) under acidic conditions, which can enhance the efficacy of radiotherapy, chemotherapy and other therapeutics for tumor treatment by remodeling the tumor microenvironment. More importantly, MnO₂ NPs also play important roles in immune regulations both in innate and adaptive immunity. In this review, we summarize the biological activities of Manganese, followed by the introduction for the biological and medical functions and mechanisms of MnO₂ NPs. What's more, we emphatically discussed the immunological regulation effects and mechanisms of MnO₂ NPs, as well as their potentials to serve as adjuvants and immunomodulators, which might benefit the development of novel vaccines and immunotherapies for more effective disease control.

When does hepatitis B virus meet long-stranded noncoding RNAs?

Hepatitis B virus (HBV) infection in humans and its associated diseases are long-standing problems. HBV can produce a large number of non-self-molecules during its life cycle, which acts as targets for innate immune recognition and initiation. Among these, interferon and its large number of downstream interferon-stimulated gene molecules are important early antiviral factors. However, the development of an effective antiviral immune response is not simple and depends not only on the delicate regulation of the immune response but also on the various mechanisms of virus-related immune escape and immune tolerance. Therefore, despite there being a relatively well-established consensus on the major pathways of the antiviral response and their component molecules, the complete clearance of HBV remains a challenge in both basic and clinical research. Long-noncoding RNAs (lncRNAs) are generally >200 bp in length and perform different functions in the RNA strand encoding the protein. As an important part of the IFN-inducible genes, interferon-stimulated lncRNAs are involved in the regulation of several HBV infection-related pathways. This review traces the basic elements of such pathways and characterizes the various recent targets of lncRNAs, which not only complement the regulatory mechanisms of pathways related to chronic HBV infection, fibrosis, and cancer promotion but also present with new potential therapeutic targets for controlling HBV infection and the malignant transformation of hepatocytes.

Type-I interferons in the immunopathogenesis and treatment of Coronavirus disease 2019

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is currently the major global health problem. Still, it continues to infect people globally and up to the end of February 2022, over 436 million confirmed cases of COVID-19, including 5.95 million deaths, were reported to the world health organization (WHO). No specific treatment is currently available for COVID-19, and the discovery of effective therapeutics requires understanding the effective immunologic and immunopathologic mechanisms behind this infection. Type-I interferons (IFN-Is), as the critical elements of the immediate immune response against viral infections, can inhibit the replication and spread of the viruses. However, the available evidence shows that the antiviral IFN-I response is impaired in patients with the severe form of COVID-19. Moreover, the administration of exogenous IFN-I in different phases of the disease can lead to various outcomes. Therefore, understanding the role of IFN-I molecules in COVID-19 development and its severity can provide valuable information for better management of this disease. This review summarizes the role of IFN-Is in the pathogenesis of COIVD-19 and discusses the importance of autoantibodies against this cytokine in the spreading of SARS-CoV-2 and control of the subsequent excessive inflammation.

Expression and Clinical Significance of Th1/Th2/Th17 Cytokines and Lymphocyte Subsets in PCNSL

Purpose

Primary central nervous system lymphoma (PCNSL) responds favorably to radiation, chemotherapy and targeted drug therapy. However survival is usually worse, the treatment-related drug resistance and recurrence are still clinical problems to be solved urgently. Studies have shown that cytokines are expressed in varying degrees in patients with lymphoma, which is significantly related to the progression, poor prognosis and drug resistance of lymphoma. We explore the expression and clinical significance of Th1/Th2/Th17 cytokines and lymphocyte subsets in patients with PCNSL to provide a more sufficient theoretical basis for its diagnosis and treatment.

Patients and Methods

We measured and analysed the levels of Th1/Th2/Th17 cytokines and the distribution of lymphocyte subsets (including Treg cells, CD3+, CD4+, CD8+, CD19+, and CD4+/CD8+) in 39 patients with PCNSL and 96 patients with diffuse large B-cell lymphoma (DLBCL) without central nervous system involvement. The cytokines of 13 healthy people and the lymphocyte subsets of 27 healthy people were measured as the control group.

Results

We found a significant difference in the level of Th1/Th2/Th17 cytokines and lymphocyte subsets between PCNSL and healthy controls, especially IL-2, after treatment, which was significantly higher than before treatment (p<0.01). However, the level of CD19+ and CD4+/CD8+ decreased while CD8+ and CD3+ increased after treatment (regardless of whether the treatment was effective), and the difference was statistically significant. In addition, our analysis of different prognostic factors found that HD-MTX-based chemotherapy appears to have a longer progression-free survival and overall survival than osimertinib-based chemotherapy.

Conclusion

There are significant differences in Th1/Th2/Th17 cytokines and lymphocyte subsets among PCNSL, DLBCL, and healthy controls, and their detection is helpful for the diagnosis, treatment, and prognosis of PCNSL. HD-MTX-based chemotherapy may still be the first choice for PCNSL.

ISG20: an enigmatic antiviral RNase targeting multiple viruses

Interferon-stimulated gene 20 kDa protein (ISG20) is a relatively understudied antiviral protein capable of inhibiting a broad spectrum of viruses. ISG20 exhibits strong RNase properties, and it belongs to the large family of DEDD exonucleases, present in both prokaryotes and eukaryotes. ISG20 was initially characterized as having strong RNase activity in vitro, suggesting that its inhibitory effects are mediated via direct degradation of viral RNAs. This mechanism of action has since been further elucidated and additional antiviral activities of ISG20 highlighted, including direct degradation of deaminated viral DNA and translational inhibition of viral RNA and nonself RNAs. This review focuses on the current understanding of the main molecular mechanisms of viral inhibition by ISG20 and discusses the latest developments on the features that govern specificity or resistance to its action.

Proteostasis Perturbations and Their Roles in Causing Sterile Inflammation and Autoinflammatory Diseases

Proteostasis, a portmanteau of the words protein and homeostasis, refers to the ability of eukaryotic cells to maintain a stable proteome by acting on protein synthesis, quality control and/or degradation. Over the last two decades, an increasing number of disorders caused by proteostasis perturbations have been identified. Depending on their molecular etiology, such diseases may be classified into ribosomopathies, proteinopathies and proteasomopathies. Strikingly, most—if not all—of these syndromes exhibit an autoinflammatory component, implying a direct cause-and-effect relationship between proteostasis disruption and the initiation of innate immune responses. In this review, we provide a comprehensive overview of the molecular pathogenesis of these disorders and summarize current knowledge of the various mechanisms by which impaired proteostasis promotes autoinflammation. We particularly focus our discussion on the notion of how cells sense and integrate proteostasis perturbations as danger signals in the context of autoinflammatory diseases to provide insights into the complex and multiple facets of sterile inflammation.

Beta interferons as immunotherapy in multiple sclerosis: a new outlook on a classic drug during the COVID-19 pandemic

Beta interferons (IFN-β) are pleiotropic cytokines with antiviral properties. They play important roles in the pathogenesis of multiple sclerosis (MS), an incurable immune-mediated disorder of the central nervous system. The clinical expression of MS is heterogeneous, with relapses of neuroinflammation and with disability accrual in considerable part unrelated to the attacks. The injectable recombinant IFN-β preparations are the first approved disease-modifying treatments for MS. They have moderate efficacy in reducing the frequency of relapses, but good long-term cost-efficacy and safety profiles, so are still widely used. They have some tolerability and adherence issues, partly mitigated in recent years by the introduction of a PEGylated formulation and use of 'smart' autoinjector devices. Their general impact on long-term disability is modest but could be further improved by developing accurate tools for identifying the patient profile of best responders to IFN-β. Here, we present the IFN-β-based immunomodulatory therapeutic approaches in MS, highlighting their place in the current coronavirus disease (COVID-19) pandemic. The potential role of IFN-β in the treatment of COVID-19 is also briefly discussed.

Participation of interferons in psoriatic inflammation

Interferons are multifunctional cytokines not expressed in the skin under normal physiological conditions. However, they are overexpressed in serum and skin lesions of patients with psoriasis and play an important role in the pathogenesis of the disease. Interferons act directly on skin resident cells and recruit and modulate inflammatory cells, thereby exacerbating psoriatic inflammation. They upregulate the expression of relevant cytokines and chemokines, facilitate excessive proliferation of keratinocytes, and enhance the formation of poorly differentiated dermal microvessels. In this review, we summarized the pathogenic effect of interferons on psoriasis and also discussed the therapeutic strategies targeting interferons.

Retroposition of the Long Transcript from Multiexon IFN-β Homologs in Ancestry Vertebrate Gave Rise to the Proximal Transcription Elements of Intronless IFN-β Promoter in Humans

IFN-β is a unique member of type I IFN in humans and contains four positive regulatory domains (PRDs), I-II-III-IV, in its promoter, which are docking sites for transcription factors IFN regulatory factor (IRF) 3/7, NF-κB, IRF3/7, and activating transcription factor 2/Jun proto-oncogene, respectively. In chicken IFN-β and zebrafish IFNφ1 promoters, a conserved PRD or PRD-like sequences have been reported. In this study, a type I IFN gene, named as xl-IFN1 in the amphibian model Xenopus laevis, was found to contain similar PRD-like sites, IV-III/I-II, in its promoter, and these PRD-like sites were proved to be functionally responsive to activating transcription factor 2/Jun proto-oncogene, IRF3/IRF7, and p65, respectively. The xl-IFN1, as IFNφ1 in zebrafish, was transcribed into a long and a short transcript, with the long transcript containing all of the transcriptional elements, including PRD-like sites and TATA box in its proximal promoter. A retroposition model was then proposed to explain the transcriptional conservation of IFNφ1, xl-IFN1, and IFN-β in chicken and humans.

Could metabolomics drive the fate of COVID-19 pandemic? A narrative review on lights and shadows

Human Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection activates a complex interaction host/virus, leading to the reprogramming of the host metabolism aimed at the energy supply for viral replication. Alterations of the host metabolic homeostasis strongly influence the immune response to SARS-CoV-2, forming the basis of a wide range of outcomes, from the asymptomatic infection to the onset of COVID-19 and up to life-threatening acute respiratory distress syndrome, vascular dysfunction, multiple organ failure, and death. Deciphering the molecular mechanisms associated with the individual susceptibility to SARS-CoV-2 infection calls for a system biology approach; this strategy can address multiple goals, including which patients will respond effectively to the therapeutic treatment. The power of metabolomics lies in the ability to recognize endogenous and exogenous metabolites within a biological sample, measuring their concentration, and identifying perturbations of biochemical pathways associated with qualitative and quantitative metabolic changes. Over the last year, a limited number of metabolomics- and lipidomics-based clinical studies in COVID-19 patients have been published and are discussed in this review. Remarkable alterations in the lipid and amino acid metabolism depict the molecular phenotype of subjects infected by SARS-CoV-2; notably, structural and functional data on the lipids-virus interaction may open new perspectives on targeted therapeutic interventions. Several limitations affect most metabolomics-based studies, slowing the routine application of metabolomics. However, moving metabolomics from bench to bedside cannot imply the mere determination of a given metabolite panel; rather, slotting metabolomics into clinical practice requires the conversion of metabolic patient-specific data into actionable clinical applications.

Differential Inhibition of HIV Replication by the 12 Interferon Alpha Subtypes

Type I interferons (IFNs) are a family of cytokines that represent a first line of defense against virus infections. The 12 different IFN-α subtypes share a receptor on target cells and trigger similar signaling cascades. Several studies have collectively shown that this apparent redundancy conceals qualitatively different responses induced by individual subtypes, which display different efficacies of inhibition of HIV replication. Some studies, however, provided evidence that the disparities are quantitative rather than qualitative. Since RNA expression analyses show a large but incomplete overlap of the genes induced, they may support both models. To explore if the IFN-α subtypes induce functionally relevant different anti-HIV activities, we have compared the efficacies of inhibition of all 12 subtypes on HIV spread and on specific steps of the viral replication cycle, including viral entry, reverse transcription, protein synthesis, and virus release. Finding different hierarchies of inhibition would validate the induction of qualitatively different responses. We found that while most subtypes similarly inhibit virus entry, they display distinctive potencies on other early steps of HIV replication. In addition, only some subtypes were able to target effectively the late steps. The extent of induction of known anti-HIV factors helps to explain some, but not all differences observed, confirming the participation of additional IFN-induced anti-HIV effectors. Our findings support the notion that different IFN-α subtypes can induce the expression of qualitatively different antiviral activities. IMPORTANCE The initial response against viruses relies in large part on type I interferons, which include 12 subtypes of IFN-α. These cytokines bind to a common receptor on the cell surface and trigger the expression of incompletely overlapping sets of genes. Whether the anti-HIV responses induced by IFN-α subtypes differ in the extent of expression or in the nature of the genes involved remains debated. Also, RNA expression profiles led to opposite conclusions, depending on the importance attributed to the induction of common or distinctive genes. To explore if relevant anti-HIV activities can be differently induced by the IFN-α subtypes, we compared their relative efficacies on specific steps of the replication cycle. We show that the hierarchy of IFN potencies depends on the step analyzed, supporting qualitatively different responses. This work will also prompt the search for novel IFN-induced anti-HIV factors acting on specific steps of the replication cycle.

Baricitinib, a JAK-STAT Inhibitor, Reduces the Cellular Toxicity of the Farnesyltransferase Inhibitor Lonafarnib in Progeria Cells

Hutchinson–Gilford progeria syndrome (HGPS) is an ultra-rare multisystem premature aging disorder that leads to early death (mean age of 14.7 years) due to myocardial infarction or stroke. Most cases have a de novo point mutation at position G608G within exon 11 of the LMNA gene. This mutation leads to the production of a permanently farnesylated truncated prelamin A protein called “progerin” that is toxic to the cells. Recently, farnesyltransferase inhibitor (FTI) lonafarnib has been approved by the FDA for the treatment of patients with HGPS. While lonafarnib treatment irrefutably ameliorates HGPS disease, it is however not a cure. FTI has been shown to cause several cellular side effects, including genomic instability as well as binucleated and donut-shaped nuclei. We report that, in addition to these cellular stresses, FTI caused an increased frequency of cytosolic DNA fragment formation. These extranuclear DNA fragments colocalized with cGAs and activated the cGAS-STING-STAT1 signaling axis, upregulating the expression of proinflammatory cytokines in FTI-treated human HGPS fibroblasts. Treatment with lonafarnib and baricitinib, a JAK-STAT inhibitor, not only prevented the activation of the cGAS STING-STAT1 pathway, but also improved the overall HGPS cellular homeostasis. These ameliorations included progerin levels, nuclear shape, proteostasis, cellular ATP, proliferation, and the reduction of cellular inflammation and senescence. Thus, we suggest that combining lonafarnib with baricitinib might provide an opportunity to reduce FTI cellular toxicity and ameliorate HGPS symptoms further than lonafarnib alone.

Pilot Analyses of Interferon Subtype Expression Profiles in Patients with Herpes Zoster or Postherpetic Neuralgia

Postherpetic neuralgia (PHN) is a painful neuropathic complication resulting from herpes zoster (HZ). The pain manifests in peripheral nerves infected by herpesviruses, mostly from reactivation of latent varicella zoster virus. Mechanistic descriptions suggest that PHN develops because of disrupted immune system signaling and inflammation or peripheral nerve damage; however, the pathophysiology is not clear. It is difficult to predict/prevent PHN manifestations of HZ patients due to the lack of accurate diagnostics. In this study, sera from healthy controls, HZ patients, and PHN patients were subjected to an interferon (IFN) expression profile (IEP) study. The corresponding cDNAs were analyzed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) using primer pairs against a panel of 21 different IFN subtypes. The results showed that distinct IEPs were observed among HZ and PHN cohorts in comparison to the healthy controls. Together, this pilot study suggested that the IEP study may be used as a molecular tool for diagnosis of PHN and assist in designing new PHN therapeutic protocols.

Interferons at the crossroad of cell death pathways during gastrointestinal inflammation and infection

Interferons (IFNs) are pleiotropic immune-modulatory cytokines that are well known for their essential role in host defense against viruses, bacteria, and other pathogenic microorganisms. They can exert both, protective or destructive functions depending on the microorganism, the targeted tissue and the cellular context. Interferon signaling results in the induction of IFN-stimulated genes (ISGs) influencing different cellular pathways including direct anti-viral/anti-bacterial response, immune-modulation or cell death. Multiple pathways leading to host cell death have been described, and it is becoming clear that depending on the cellular context, IFN-induced cell death can be beneficial for both: host and pathogen. Accordingly, activation or repression of corresponding signaling mechanisms occurs during various types of infection but is also an important pathway for gastrointestinal inflammation and tissue damage. In this review, we summarize the role of interferons at the crossroad of various cell death pathways in the gut during inflammation and infection.

Protein hormone fragmentation in intercellular signaling: hormones as nested information systems

This study explores the hypothesis that protein hormones are nested information systems in which initial products of gene transcription, and their subsequent protein fragments, before and after secretion and initial target cell action, play additional physiological regulatory roles. The study produced four tools and key results: (1) a problem approach that proceeds, with examples and suggestions for in vivo organismal functional tests for peptide-protein interactions, from proteolytic breakdown prediction to models of hormone fragment modulation of protein-protein binding motifs in unrelated proteins; (2) a catalog of 461 known soluble human protein hormones and their predicted fragmentation patterns; (3) an analysis of the predicted proteolytic patterns of the canonical protein hormone transcripts demonstrating near-universal persistence of 9 ± 7 peptides of 8 ± 8 amino acids even after cleavage with 24 proteases from four protease classes; and (4) a coincidence analysis of the predicted proteolysis locations and the 1939 exon junctions within the transcripts that shows an excess (P < 0.001) of predicted proteolysis within 10 residues, especially at the exonal junction (P < 0.01). It appears all protein hormone transcripts generate multiple fragments the size of peptide hormones or protein-protein binding domains that may alter intracellular or extracellular functions by acting as modulators of metabolic enzymes, transduction factors, protein binding proteins, or hormone receptors. High proteolytic frequency at exonal junctions suggests proteolysis has evolved, as a complement to gene exon fusion, to extract structures or functions within single exons or protein segments to simplify the genome by discarding archaic one-exon genes.

Targeting Impaired Antimicrobial Immunity in the Brain for the Treatment of Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia and aging is the most common risk factor for developing the disease. The etiology of AD is not known but AD may be considered as a clinical syndrome with multiple causal pathways contributing to it. The amyloid cascade hypothesis, claiming that excess production or reduced clearance of amyloid-beta (Aβ) and its aggregation into amyloid plaques, was accepted for a long time as the main cause of AD. However, many studies showed that Aβ is a frequent consequence of many challenges/pathologic processes occurring in the brain for decades. A key factor, sustained by experimental data, is that low-grade infection leading to production and deposition of Aβ, which has antimicrobial activity, precedes the development of clinically apparent AD. This infection is chronic, low grade, largely clinically silent for decades because of a nearly efficient antimicrobial immune response in the brain. A chronic inflammatory state is induced that results in neurodegeneration. Interventions that appear to prevent, retard or mitigate the development of AD also appear to modify the disease. In this review, we conceptualize further that the changes in the brain antimicrobial immune response during aging and especially in AD sufferers serve as a foundation that could lead to improved treatment strategies for preventing or decreasing the progression of AD in a disease-modifying treatment.

The Dramatic Role of IFN Family in Aberrant Inflammatory Osteolysis

Skeletal system has been considered a highly dynamic system, in which bone-forming osteoblasts and bone-resorbing osteoclasts go through a continuous remodeling cycle to maintain homeostasis of bone matrix. It has been well acknowledged that interferons (IFNs), acting as a subgroup of cytokines, not only have crucial effects on regulating immunology but also could modulate the dynamic balance of bone matrix. In the light of different isoforms, IFNs have been divided into three major categories in terms of amino acid sequences, recognition of specific receptors and biological activities. Currently, type I IFNs consist of a multi-gene family with several subtypes, of which IFN-α exerts pro-osteoblastogenic effects to activate osteoblast differentiation and inhibits osteoclast fusion to maintain bone matrix integrity. Meanwhile, IFN-β suppresses osteoblast-mediated bone remodeling as well as exhibits inhibitory effects on osteoclast differentiation to attenuate bone resorption. Type II IFN constitutes the only type, IFN-γ, which exerts regulatory effects on osteoclastic bone resorption and osteoblastic bone formation by biphasic ways. Interestingly, type III IFNs are regarded as new members of IFN family composed of four members, including IFN-λ1 (IL-29), IFN-λ2 (IL-28A), IFN-λ3 (IL-28B) and IFN-λ4, which have been certified to participate in bone destruction. However, the direct regulatory mechanisms underlying how type III IFNs modulate the metabolic balance of bone matrix, remains poorly elucidated. In this review, we have summarized functions of IFN family during physiological and pathological conditions and described the mechanisms by which IFNs maintain bone matrix homeostasis via affecting the osteoclast-osteoblast crosstalk. In addition, the potential therapeutic effects of IFNs on inflammatory bone destruction diseases such as rheumatoid arthritis (RA), osteoarthritis (OA) and infectious bone diseases are also well displayed, which are based on the predominant role of IFNs in modulating the dynamic equilibrium of bone matrix.

In vitro effects of Type I interferons (IFNτ and IFNα) on bovine hepatocytes cultured with or without Kupffer cells

In cattle, maternal recognition of early pregnancy depends on the effects of the embryonic signal interferon (IFN)-τ. IFN-stimulated genes have been upregulated in the maternal liver during early pregnancy. In this study, primary hepatocyte cell culture models were evaluated for their suitability to test Type I IFN effects invitro. The expression of target genes (interferon-stimulated gene 15 (ISG-15), interferon-induced GTP-binding protein (MX-1), C-X-C motif chemokine 10 (CXCL-10), CXCL-5, insulin-like growth factor 1 (IGF-1), IGF binding protein 2 (IGFBP-2)) was measured using reverse transcription-quantitative polymerase chain reaction in hepatocytes from monoculture or in indirect coculture with Kupffer cells (HKCid) on Days 1, 2, 3 and 4 of culture (n=21 donor cows). Gene expression was also measured on Day 4 after challenging the cultures with recombinant IFNτ, IFNα, progesterone (P4), IFNτ+IFNα or IFNτ+P4 for 6h. A significant increase in the mRNA expression of target genes in hepatocytes was shown in response to stimulation with IFNτ. The Kupffer cells in coculture did not influence the effects of IFNτ in hepatocytes. In conclusion, primary bovine hepatocyte cultures are suitable for stimulation experiments with Type I IFNs and as an extrauterine model for embryo-maternal communication. The proposed endocrine action of IFNτ in the liver may affect maternal metabolism and immune function in the liver.

Constitutive low expression of antiviral effectors sensitizes melanoma cells to a novel oncolytic virus

STAT1 is a critical effector and a target gene of interferon (IFN) signaling, and thus a central mediator of antiviral responses. As both a mediator and a target of IFN signals, STAT1 expression reports on, and determines IFN activity. Gene expression analyses of melanoma patient samples revealed varied levels of STAT1 expression, which highly correlated with expression of >700 genes. The ability of oncolytic viruses to exploit tumor-induced defects to antiviral responses suggests that oncolytic viruses may efficiently target a subset of melanomas, yet these should be defined. We modeled this scenario with murine B16F10 melanomas, immortalized skin fibroblasts as controls and a novel oncolytic virus, EHDV-TAU. In B16F10 cells, constitutive low expression of STAT1 and its target genes, which included intracellular pattern recognition receptors (PRRs), correlated with their inability to mount IFN-based antiviral responses upon EHDV-TAU challenge, and with potency of EHDV-TAU-induced oncolysis. This underexpression of interferon stimulated genes (ISGs) and PRRs, and the inability of EHDV-TAU to induce their expression, were reversed by epigenetic modifiers, suggesting epigenetic silencing as a basis for their underexpression. Despite their inability to mount IFN/STAT-based responses upon viral infection, EHDV-TAU infected B16F10 cells secreted immune-stimulatory chemokines. Accordingly, in vivo, EHDV-TAU enhanced intratumoral infiltration of cytotoxic T-cells and reduced growth of local and distant tumors. We propose that "STAT1 signatures" should guide melanoma virotherapy treatments, and that oncolytic viruses such as EHDV-TAU have the potential to exploit the cellular context of low-STAT1 tumors.

The Key Roles of Interferon Lambda in Human Molecular Defense against Respiratory Viral Infections

Interferons (IFN) are crucial for the innate immune response. Slightly more than two decades ago, a new type of IFN was discovered: the lambda IFN (type III IFN). Like other IFN, the type III IFN display antiviral activity against a wide variety of infections, they induce expression of antiviral, interferon-stimulated genes (MX1, OAS, IFITM1), and they have immuno-modulatory activities that shape adaptive immune responses. Unlike other IFN, the type III IFN signal through distinct receptors is limited to a few cell types, primarily mucosal epithelial cells. As a consequence of their greater and more durable production in nasal and respiratory tissues, they can determine the outcome of respiratory infections. This review is focused on the role of IFN-λ in the pathogenesis of respiratory viral infections, with influenza as a prime example. The influenza virus is a major public health problem, causing up to half a million lethal infections annually. Moreover, the virus has been the cause of four pandemics over the last century. Although IFN-λ are increasingly being tested in antiviral therapy, they can have a negative influence on epithelial tissue recovery and increase the risk of secondary bacterial infections. Therefore, IFN-λ expression deserves increased scrutiny as a key factor in the host immune response to infection.

Antiviral Immune Response in Alzheimer's Disease: Connecting the Dots

Alzheimer’s disease (AD) represents an enormous public health challenge currently and with increasing urgency in the coming decades. Our understanding of the etiology and pathogenesis of AD is rather incomplete, which is manifested in stagnated therapeutic developments. Apart from the well-established Amyloid Hypothesis of AD, gaining traction in recent years is the Pathogen Hypothesis, which postulates a causal role of infectious agents in the development of AD. Particularly, infection by viruses, among a diverse range of microorganisms, has been implicated. Recently, we described a prominent antiviral immune response in human AD brains as well as murine amyloid beta models, which has consequential effects on neuropathology. Such findings expectedly allude to the question about viral infections and AD. In this Perspective, we would like to discuss the molecular mechanism underlying the antiviral immune response, highlight how such pathway directly promotes AD pathogenesis, and depict a multilayered connection between antiviral immune response and other agents and factors relevant to AD. By tying together these threads of evidence, we provide a cohesive perspective on the uprising of antiviral immune response in AD.

Activation of Fc gamma receptor IIb up-regulates the production of interferon-alpha and interferon-gamma in porcine alveolar macrophages during PRRSV infection

Porcine Fc gamma receptor IIb (FcγRIIb) has been cloned and characterized for many years. However, the role of FcγRIIb in innate antiviral response to porcine reproductive and respiratory syndrome virus (PRRSV) infection has not yet been well investigated. In current study, our results showed that specific activation of FcγRIIb in porcine alveolar macrophages (PAMs) significantly enhanced the production of interferon-alpha (IFN-α) and interferon-gamma (IFN-γ), and significantly repressed the production of transforming growth factor beta 1 (TGF-β1). In addition, our results showed that specific activation of FcγRIIb in PAMs cells in PRRSV infection not only significantly increased the production of IFN-α and IFN-γ, but also significantly decreased the production of TGF-β1, and significantly inhibited PRRSV replication level. In summary, our studies indicated that FcγRIIb signaling up-regulated the production of IFN-α and IFN-γ in PAMs cells in vitro, in response to PRRSV infection.

Type I interferon response drives neuroinflammation and synapse loss in Alzheimer disease

Type I interferon (IFN) is a key cytokine that curbs viral infection and cell malignancy. Previously, we demonstrated a potent IFN immunogenicity of nucleic acid-containing (NA-containing) amyloid fibrils in the periphery. Here, we investigated whether IFN is associated with β-amyloidosis inside the brain and contributes to neuropathology. An IFN-stimulated gene (ISG) signature was detected in the brains of multiple murine Alzheimer disease (AD) models, a phenomenon also observed in WT mouse brain challenged with generic NA-containing amyloid fibrils. In vitro, microglia innately responded to NA-containing amyloid fibrils. In AD models, activated ISG-expressing microglia exclusively surrounded NA+ amyloid β plaques, which accumulated in an age-dependent manner. Brain administration of rIFN-β resulted in microglial activation and complement C3-dependent synapse elimination in vivo. Conversely, selective IFN receptor blockade effectively diminished the ongoing microgliosis and synapse loss in AD models. Moreover, we detected activated ISG-expressing microglia enveloping NA-containing neuritic plaques in postmortem brains of patients with AD. Gene expression interrogation revealed that IFN pathway was grossly upregulated in clinical AD and significantly correlated with disease severity and complement activation. Therefore, IFN constitutes a pivotal element within the neuroinflammatory network of AD and critically contributes to neuropathogenic processes.

Egyptian Rousette IFN-ω Subtypes Elicit Distinct Antiviral Effects and Transcriptional Responses in Conspecific Cells

Bats host a number of viruses that cause severe disease in humans without experiencing overt symptoms of disease themselves. While the mechanisms underlying this ability to avoid sickness are not known, deep sequencing studies of bat genomes have uncovered genetic adaptations that may have functional importance in the antiviral response of these animals. Egyptian rousette bats (Rousettus aegyptiacus) are the natural reservoir hosts of Marburg virus (MARV). In contrast to humans, these bats do not become sick when infected with MARV. A striking difference to the human genome is that Egyptian rousettes have an expanded repertoire of IFNW genes. To probe the biological implications of this expansion, we synthesized IFN-ω4 and IFN-ω9 proteins and tested their antiviral activity in Egyptian rousette cells. Both IFN-ω4 and IFN-ω9 showed antiviral activity against RNA viruses, including MARV, with IFN-ω9 being more efficient than IFN-ω4. Using RNA-Seq, we examined the transcriptional response induced by each protein. Although the sets of genes induced by the two IFNs were largely overlapping, IFN-ω9 induced a more rapid and intense response than did IFN-ω4. About 13% of genes induced by IFN-ω treatment are not found in the Interferome or other ISG databases, indicating that they may be uniquely IFN-responsive in this bat.

Assessment of TLR4 and TLR9 signaling and correlation with human papillomavirus status and histopathologic parameters in oral tongue squamous cell carcinoma

OBJECTIVES

Toll-like receptors (TLRs) may promote or inhibit tumor progression. The aim of this study was to assess the expression of TLR4 and TLR9 and their downstream targets in oral tongue squamous cell carcinoma (OTSCC) in correlation with histopathologic parameters and human papillomavirus (HPV) status.

STUDY DESIGN

OTSCC (fully or superficially invasive and in situ) were studied. Immunohistochemical expression of TLR4, TLR9, nuclear factor-κΒ (NF-κΒ/p65), and interferon-β (IFN-β) was evaluated in tumor and inflammatory cells and in adjacent morphologically normal mucosa. HPV status was also determined.

RESULTS

TLR4 showed increased expression levels in tumor and infiltrating inflammatory cells compared with adjacent mucosa, especially in fully invasive cases; a negative correlation between TLR4 levels in inflammatory cells and tumor grade was observed. TLR9 was upregulated in tumor and infiltrating inflammatory cells compared with the adjacent mucosa; its expression in inflammatory cells was higher in well differentiated tumors. NF-κΒ and IFN-β were elevated in cancerous tissues, especially in fully invasive cases, and positively correlated with TLR4 and/or TLR9. HPV positivity (detected in 15.9% of the cases) demonstrated positive correlation with TLR9 and NF-κΒ levels.

CONCLUSIONS

TLR4 and TLR9 are upregulated in OTSCC and its microenvironment and, by affecting important downstream molecules, such as NF-κB and IFN-β, may play a role in oral cancer development and progression.

The Comparison Between the Mutated HuIFN-β 27-101 and the Wild Type Interferon β: the Comprehensive In Silico Study to Evaluate the Effect of Mutations on IFN-β

Purpose: Interferon beta (IFN-β) is used to combat multiple sclerosis (MS) disease. Creating R27T and V101F mutations (mHuIFN-β-27 and mHuIFN-β-101) is one of the tasks performed to improve human interferon beta (HuIFN-β) half-life, function and expression. In this work, the impact of R27T and V101F mutations in recombinant IFN-β on its binding to interferon receptors were studied by molecular docking.

Methods: This work was performed through in silico study. The simulation of mutation was performed using the online Rosetta Backrub software and checked using server verify3D. Comparison of access to the solvent of the amino acids in the structures created was performed using the asaview online server. Also, the effect of mutations on the fold of the protein was reviewed by the online HOPE server. The molecular docking was performed between HuIFN-β and the external region of IFNAR receptor using the online ClusPro2 protein-protein docking server.

Results: The comparison of the values of the negative binding energy (ΔGbind) obtained from protein-protein molecular docking between IFNAR receptor and HuIFN-β, mHuIFN-β-27, mHuIFN-β-101 and mHuIFN-β-27-101 ligands did not show a significant difference, and these differences do not see any meaningful relationship between them (P > 0.9999).

Conclusion: Regarding these results, it can be concluded that these mutations do not have a negative effect on the composition of the complex rHuIFN-β/IFNAR. So, they do not interfere with the binding of the IFN-β to the receptor. It is concluded that the quality of the rHuIFN-β is improved by introducing these two mutations.

The cGAS Paradox: Contrasting Roles for cGAS-STING Pathway in Chromosomal Instability

Chromosomal instability (CIN) is an intricate phenomenon that is often found in human cancer, characterized by persisting errors in chromosome segregation. This ongoing chromosome mis-segregation results in structural and numerical chromosomal abnormalities that have been widely described to promote tumor evolution. In addition to being a driver of tumor evolution, recent evidence demonstrates CIN to be the central node of the crosstalk between a tumor and its surrounding microenvironment, as mediated by the cGAS-STING pathway. The role that cGAS-STING signaling exerts on CIN tumors is both complex and paradoxical. On one hand, the cGAS-STING axis promotes the clearance of CIN tumors through recruitment of immune cells, thus suppressing tumor progression. On the other hand, the cGAS-STING pathway has been described to be the major regulator in the promotion of metastasis of CIN tumors. Here, we review this dual role of the cGAS-STING pathway in the context of chromosomal instability and discuss the potential therapeutic implications of cGAS-STING signaling for targeting CIN tumors.

Wenshen decoction suppresses inflammation in IL-33-induced asthma murine model via inhibiting ILC2 activation

Background

Wenshen decoction, consisting of Epimedium brevicornu Maxim, Morinda officinalis How and Cnidium monnieri (L.) Cusson, has favorable efficacy in the treatment of asthma in China.

Methods

The present study investigated the potential immunomodulatory mechanism underlying the therapeutic effects of Wenshen decoction on mouse asthma.

Results

Oral Wenshen decoction could ameliorate the production of IL-4, IL-5, IL-13 in the bronchoalveolar lavage fluid (BALF), reduce serum IgE, and improve the airway hyperresponsiveness (AHR) and airway inflammation in the BALB/c mice after intranasal treatment with recombinant IL-33. Moreover, Wenshen decoction reduced ILC2 and RORα mRNA expression, decreased the mRNA expression of ICOS and ST2 in the lung, but significantly increased the production of IFN-γ.

Conclusions

Our study indicates that Wenshen decoction may inhibit the activation of ILC2 through the IL-33/ST2/ICOS pathway to further suppress airway inflammation and AHR in the asthmatic mice, and the increased IFN-γ might be related to the effects of Wenshen decoction on ILC2.

Validation of a cell-based colorimetric reporter gene assay for the evaluation of Type I Interferons

The biotherapeutic type I interferons (IFN-I) are indicated to treat several diseases. These products are regulated to guarantee safety and efficacy through critical quality attributes. For this purpose, the development of robust assays is required, followed by its validation to demonstrate their suitability for its intended purpose. Despite there are some commercial kits to evaluate IFN-I signaling, these are focused on measuring in vitro biological response instead of their validation, which is a pharmaceutical industry requirement. The aim of this work was to validate the HEK-Blue IFN-α/β system evaluating the biological activity of IFN-α/β under good laboratory practices, according to international standards. Our results demonstrated that HEK-Blue IFN-α/β system comply with accuracy (r²>0.95) precision (CV < 20%) and specificity for both IFN-α/β; confirming that this assay is robust for this biotherapeutics' evaluation. Thereby, this bioassay could be implemented as a complementary method to the classical anti-proliferative and anti-viral assays under quality control environments.

RNA viruses promote activation of the NLRP3 inflammasome through cytopathogenic effect-induced potassium efflux

Early detection of viruses by the innate immune system is crucial for host defense. The NLRP3 inflammasome, through activation of caspase-1, promotes the maturation of IL-1β and IL-18, which are critical for antiviral immunity and inflammatory response. However, the mechanism by which viruses activate this inflammasome is still debated. Here, we report that the replication of cytopathogenic RNA viruses such as vesicular stomatitis virus (VSV) or encephalomyocarditis virus (EMCV) induced a lytic cell death leading to potassium efflux, the common trigger of NLRP3 inflammasome activation. This lytic cell death was not prevented by a chemical or genetic inhibition of apoptosis, pyroptosis, or necroptosis but required the viral replication. Hence, the viruses that stimulated type I IFNs production after their sensing did not activate NLRP3 inflammasome due to an inhibition of their replication. In contrast, NLRP3 inflammasome activation induced by RNA virus infection was stimulated in IFNAR-deficient or MAVS-deficient cells consequently to an increased viral replication and ensuing lytic cell death. Therefore, in a context of inefficient IFN response, viral replication-induced lytic cell death activates of the NLRP3 inflammasome to fight against infection.

Sequence analysis and characterization of type I interferon and type II interferon from the critically endangered sturgeon species, A. dabryanus and A. sinensis

In the present study, we identify three type I interferon (IFN) genes (Ad/AsIFNe1-3) and a type II IFN gene (Ad/AsIFNγ) from the Dabry's sturgeon (Acipenser dabryanus) and the Chinese sturgeon (Acipenser sinensis). Sequence analysis revealed that Ad/AsIFNe1-3 and Ad/AsIFNγ contain several conserved characteristics, including signal peptides, interferon alpha, beta, and delta (IFabd) domains, and N-glycosylation sites. Ad/AsIFNe1-3 belongs to the type I IFN group I subgroup, possessing two conserved cysteines residues (C1 and C3), and Ad/AsIFNγ contained a conserved nuclear localization sequence (NLS) motif. Ad/AsIFNe1-3 and Ad/AsIFNγ contain signature motifs indicative of their corresponding IFN group. The Ad/AsIFNe1-3 and Ad/AsIFNγ genes were found to consist of 5 exons/4 introns and 4 exons/3 introns, respectively. These IFNs were separated by four phase 0 introns (type I IFN) and three phase 0 introns (type II IFN). The sequences of IFNe1-3 and IFNγ from the Dabry's sturgeon and the Chinese sturgeon were closely aligned, suggested that these two species are closely related. Phylogenetic analysis revealed that Ad/AsIFNe1-3 and Ad/AsIFNγ clustered together with the corresponding homologous proteins from other fish species. AdIFNe1-3 were found to be high expressed in early embryonic development, suggesting that AdIFNe1-3 might indicate maternal transmission, while AdIFNγ may not mediate embryonic development. Tissue distribution analysis revealed that AdIFNe1-3 and AdIFNγ carry out biological functions in immune and non-immune tissues compartments. AdIFNe1-3 and AdIFNγ can be stimulated by polyinosinic-polycytidylic acid (poly I:C) and lipopolysaccharides (LPS). AdIFNe1-3 have stronger antiviral activity than AdIFNγ, and AdIFNγ has a stronger antibacterial activity than AdIFNe1-3. The differential responses of these genes to poly I:C and LPS suggest differences in the mechanisms of defense against viruses and bacteria.

The Strategy of Picornavirus Evading Host Antiviral Responses: Non-structural Proteins Suppress the Production of IFNs

Viral infections trigger the innate immune system to produce interferons (IFNs), which play important role in host antiviral responses. Co-evolution of viruses with their hosts has favored development of various strategies to evade the effects of IFNs, enabling viruses to survive inside host cells. One such strategy involves inhibition of IFN signaling pathways by non-structural proteins. In this review, we provide a brief overview of host signaling pathways inducing IFN production and their suppression by picornavirus non-structural proteins. Using this strategy, picornaviruses can evade the host immune response and replicate inside host cells.

The Interferon (IFN) Class of Cytokines and the IFN Regulatory Factor (IRF) Transcription Factor Family

Interferons (IFNs) are a broad class of cytokines elicited on challenge to the host defense and are essential for mobilizing immune responses to pathogens. Divided into three classes, type I, type II, and type III, all IFNs share in common the ability to evoke antiviral activities initiated by the interaction with their cognate receptors. The nine-member IFN regulatory factor (IRF) family, first discovered in the context of transcriptional regulation of type I IFN genes following viral infection, are pivotal for the regulation of the IFN responses. In this review, we briefly describe cardinal features of the three types of IFNs and then focus on the role of the IRF family members in the regulation of each IFN system.