Type I interferon signaling, regulation and gene stimulation in chronic virus infection

Type I Interferon Signalling and Ischemic Stroke: Mechanisms and Therapeutic Potentials

Type I interferon (IFN-I) signalling is intricately involved in the pathogenesis of multiple infectious diseases, autoimmune diseases, and neurological diseases. Acute ischemic stroke provokes overactivation of IFN-I signalling within the injured brain, particularly in microglia. Following cerebral ischemia, damage-associated molecular patterns (DAMPs) released from injured neural cells elicit marked proinflammatory episodes within minutes. Among these, self-nucleic acids, including nuclear DNA and mitochondrial DNA (mtDNA), have been recognized as a critical alarm signal to fan the flames of neuroinflammation, predominantly via inducing IFN-I signalling activation in microglia. The concept of interferon-responsive microglia (IRM), marked by upregulation of a plethora of IFN-stimulated genes, has been emergingly elucidated in ischemic mouse brains, particularly in aged ones. Among the pattern recognition receptors responsible for IFN-I induction, cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) plays integral roles in potentiating microglia-driven neuroinflammation and secondary brain injury after cerebral ischemia. Here, we aim to provide an up-to-date review on the multifaceted roles of IFN-I signalling, the detailed molecular and cellular mechanisms leading to and resulting from aberrant IFN-I signalling activation after cerebral ischemia, and the therapeutic potentials. A thorough exploration of these above points will inform our quest for IFN-based therapies as effective immunomodulatory therapeutics to complement the limited repertoire of thrombolytic agents, thereby facilitating the translation from bench to bedside.

IFN-γ Approaches in Tumor Suppression, Its Challenges, and Future Directions: A Review of Recent Advances

IFN-γ is recognized as an immunoregulatory cytokine due to its dual role in both accelerating and dampening immunological responses. Accordingly, in the context of tumor immunotherapy, the therapeutic outcome of IFN-γ is contingent upon factors such as dosage and the expression status of downstream signaling molecules. Furthermore, the coadministration of IFN-γ with various immunestimulatory agents, including anticheckpoint inhibitors, chemotherapeutic agents, and herbal-based medicines, may potentially overcome the IFN-γ-related challenges and enhance the response rate. We decipher the mechanisms of tumor cell eradication facilitated by IFN-γ, the last achievements in IFN-γ-mediated tumor immunotherapy across various cancers, and the strategies to address the failure of IFN-γ-based tumor immunotherapy. Unraveling the molecular mechanisms that lead to failure in IFN-γ-based antitumor actions could assist in pinpointing therapeutic agents that target the immune-modulatory features of IFN-γ, thereby increasing the antitumor response rate.

VAPA suppresses BEFV and VSV-induced type I IFNs signaling response by targeting JAK1 for NEDD4-mediated ubiquitin-proteasome degradation

VAMP-associated protein A (VAPA) binds to various proteins involved in multiple cellular processes, however, its role in the regulation of type I interferons (IFN-I) signaling has not been elucidated. In this study, we demonstrate that VAPA negatively regulates the IFN-I signaling during bovine epidemic fever virus (BEFV) and vesicular stomatitis virus (VSV) infection. Upon treatment with IFN-β, VAPA negatively regulates the JAK-STAT signaling pathway. Further studies show that VAPA inhibits the IFN-I signaling by promoting the degradation of JAK1 through the ubiquitin-proteasome system during BEFV and VSV infection. Mechanistically, VAPA facilitates the interaction between the E3 ubiquitin ligase NEDD4 and JAK1, thereby enhancing the ubiquitination and subsequent degradation of JAK1. Furthermore, viral titers are markedly reduced, and the promoting effect of VAPA on VSV or BEFV replication is attenuated in NEDD4-deficient cells. Taken together, our findings reveal a novel role for VAPA in negatively regulating the IFN-I signaling response and provide a molecular basis for the design of targeted antiviral agents.

The African swine fever virus B125R protein antagonizes JAK-STAT signalling by promoting the degradation of IFNAR2

African swine fever (ASF) is a highly contagious and severe hemorrhagic disease caused by African swine fever virus (ASFV). Currently, few safe and effective vaccines or antiviral drugs are available for its prevention. Interferon (IFN), a key component of innate antiviral immunity, induces interferon-stimulated genes (ISGs) by activating the JAK-STAT signalling pathway, resulting in antiviral effects. ASFV strains, including ASFV SY18, ASFV HLJ18, and ASFV BA71V, are highly sensitive to IFN-I treatment; however, the mechanisms by which ASFV antagonizes the host type I IFN response have not been fully elucidated. In this study, we identified the ASFV B125R protein (pB125R) as a negative regulator of the JAK-STAT pathway. We observed that ectopically expressed pB125R significantly suppressed the IFN-β-triggered activation of JAK-STAT signalling in HEK293T and PK-15 cells. Mechanistic studies revealed that pB125R binds to IFNAR2 and promotes its autophagic degradation, impairing the signal transduction of the IFN response at an early stage. This ultimately reduces the nuclear translocation of the ISGF3 complex and decreases ISG production. Our findings highlight the immunosuppressive activity of pB125R and reveal a novel mechanism by which ASFV evades the host IFN response, contributing to potential strategies for developing vaccines and therapeutics against ASF.

Shared Mechanisms of Blood-Brain Barrier Dysfunction and Neuroinflammation in Coronavirus Disease 2019 and Alzheimer Disease

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has highlighted the virus's impact on the central nervous system and its potential to exacerbate neurodegenerative diseases, like Alzheimer disease (AD). Emerging evidence suggests that SARS-CoV-2 infection contributes to chronic neuroinflammation, a key driver in the etiopathogenesis of AD. Shared mechanisms, including blood-brain barrier (BBB) dysfunction, systemic inflammation, and activation of immune pathways, may link SARS-CoV-2 infection to AD onset and/or progression, particularly among vulnerable individuals, such as those of advanced age. This review explores convergent pathways involving the renin-angiotensin-aldosterone system, Wnt/β-catenin signaling, NF-κB activation, and interferon signaling, focusing on their roles in BBB integrity and neuroinflammation. SARS-CoV-2-mediated angiotensin-converting enzyme 2 depletion disrupts renin-angiotensin-aldosterone system homeostasis, favoring proinflammatory signaling that parallels vascular dysfunction in AD. Dysregulation of Wnt/β-catenin signaling exacerbates BBB permeability, whereas NF-κB and interferon pathways contribute to BBB breakdown and propagate central nervous system inflammation via endothelial and immune cell activation. These interactions may amplify prodromal AD pathology and/or initiate AD pathogenesis. By identifying mechanistic overlaps between COVID-19 and AD, this review underlines the need for therapeutic strategies targeting shared pathways of inflammation and BBB dysfunction. Understanding these connections is critical for mitigating the long-term neurologic sequelae of COVID-19 and reducing the burden of AD.

Guardians at the gate: Unraveling Type I interferon's role and challenges posed by anti-interferon antibodies in COVID-19

The intricate interplay involving Type I interferon (IFN), anti-interferon antibodies, and COVID-19 elucidates a complex symphony within the immune system. This chapter thoroughly explores the dynamic landscape of Type I IFN, delineating its pivotal role as the guardian of the immune response. As SARS-CoV-2 engages the host, the delicate balance of IFN induction and signaling pathways is disrupted, resulting in a nuanced impact on the severity and pathogenesis of COVID-19. Clinical studies illuminate a critical link between impaired IFN response and severe outcomes, uncovering genetic factors contributing to susceptibility. Furthermore, the emergence of anti-interferon antibodies proves to be a disruptive force, compromising the immune arsenal and correlating with disease severity. Our chapter encompasses diagnostic and prognostic implications, highlighting the importance of assays in identifying levels of IFN and anti-interferon antibodies. This chapter examines the possible incorporation of interferon-related biomarkers in COVID-19 diagnostics, offering predictive insights into disease progression. On the therapeutic front, efforts to manipulate the IFN pathway undergo scrutiny, encountering complexities in light of anti-interferon antibodies. This chapter concludes by outlining prospective avenues for precision medicine, emphasizing the imperative need for a comprehensive comprehension of the IFN landscape and its intricate interaction with COVID-19.

Identification and immunoassay of biomarkers associated with T cell exhaustion in systemic lupus erythematosus

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease with unclear etiology. T cell exhaustion (TEX) suppresses the immune response and can be a potential therapeutic strategy for autoimmune diseases. Therefore, this study primarily investigated the mechanism by which TEX influences SLE, offering a novel target for its treatment.

Methods

GSE72326 and GSE81622 were utilized in this study. TEX related genes (TEX-RGs) were obtained from the published literature. Differentially expressed genes (DEGs) were obtained through differential expression analysis. Subsequently, candidate genes were selected by overlapping DEGs and TEX-RGs. These candidate genes underwent protein-protein interactions (PPIs) analysis for further screening. Machine learning was applied to identify candidate key genes from the PPI-identified genes. The candidate key genes exhibiting an area under the receiver operating characteristic (ROC) curve (AUC) greater than 0.7, along with consistent expression trends and significant differences in GSE72326 and GSE81622 were defined as biomarkers. Additionally, enrichment analysis, immune infiltration analysis, chemical compounds prediction and molecular docking were carried out. Importantly, the biomarkers were validated for expression by reverse transcription-quantitative polymerase chain reaction (RT-qPCR).

Results

The biomarkers MX1, LY6E, IFI44 and OASL were screened by overlapping 327 DEGs and 1,408 TEX-RGs. Gene set enrichment analysis (GSEA) showed that there was a significant positive correlation between the expression of these biomarkers and immune-related pathways, such as the NOD-like receptor signaling pathway, Toll-like receptor signaling pathway and RIG-I-like receptor signaling pathway significant positive correlation. The immune infiltration of 8 types of immune cells differed significantly in SLE. Naive B cells, resting memory CD4 T cells and resting NK cells were significantly down-regulated in the SLE group. 4 biomarkers showed the highest correlation with resting memory CD4 T cells. Bisphenol A targeted OASL and LY6E, whereas acetaminophen targeted IFI44 and MX1.The binding activity between the biomarkers and the chemical compounds targeting them was very strong. Finally, RT-qPCR expression of MX1, LY6E, IFI44 and OASL was consistent with the results of the dataset.

Conclusion

MX1, LY6E, IFI44 and OASL were identified as biomarkers related to TEX in SLE. These biomarkers could be detected in the blood for early diagnosis of the disease or to monitor the efficacy of the disease treatment, thus providing a new target for the management of SLE.

A focused report on IFN-1 targeted therapies for lupus erythematosus

INTRODUCTION

Patients with Systemic Lupus Erythematosus (SLE) experience varied manifestations and unpredictable flares, complicating treatment and drug development. Despite these challenges, anifrolumab, voclosporin, and belimumab were approved by FDA. These treatments complement, but don't replace, traditional therapies like NSAIDs, corticosteroids, antimalarials, and immunosuppressives. Therefore, there remains an unmet need for more effective medications targeting excessive proinflammatory cytokines in SLE patients.

AREAS COVERED

This review summarizes the clinical trial outcomes of four upcoming medications targeting cytokine activity: Litifilimab showed a 7-point reduction in CLASI-A in its phase II trial. Daxdilimab was unsuccessful in its phase II trial. Anifrolumab reduced SLE activity in both phase II and III trials. Deucravacitinib decreased disease activity by multiple measures in its phase II trial.

EXPERT OPINION

High levels of IFN-I (type 1 interferon) are present in most SLE patients, making this pathway an attractive target for drug development. Litifilimab downregulates IFN-I by targeting BDCA2, while dexadilimab targets ILT7 to recruit effector cells, reducing IFN-I production by killing PDCs. Anifrolumab binds to the IFN-I receptor, blocking the activity of all IFN-Is, and deucravacitinib reduces IFN-I by inhibiting TYK2, thereby interfering with downstream signaling. Therapies that target IFN-I represents a promising class of medications for SLE patients.

Global MicroRNA Profiling of HSV-1 Infected Cornea Identifies miR-329 as a Novel Regulator of Virus Infection

Purpose

Although the mechanisms underlying herpes simplex virus type-1 (HSV-1) ocular infection have been extensively studied, the role of host microRNAs (miRNAs) in the pathobiology of herpetic keratitis (HK) is not well understood. The aim of this study was to identify endogenous miRNA regulators involved in the progression of HSV-1 ocular infection.

Methods

C57BL/6 mice were infected with HSV-1 strain McKrae following epithelial debridement, and corneal miRNA profiles were analyzed at various time points using miRNA sequencing (miRNA-seq). The miRNA expression was measured at 2, 4, 6, and 10 days post-infection. Ingenuity Pathway Analysis (IPA) was used to identify immune pathways potentially targeted by differentially expressed miRNAs. The role of selected miRNAs in viral entry and replication was assessed by overexpression in murine embryonic fibroblasts (MEFs) and human corneal epithelial cells (HCEs).

Results

A total of 32 miRNAs at 2 days post-infection, 21 miRNAs at 4 days post-infection, 140 miRNAs at 6 days post-infection, and 27 miRNAs at 10 days post-infection showed significant changes in expression. IPA revealed that differentially expressed miRNAs targeted several immune pathways, including TLR and interferon signaling. Notably, mmu-miR-184-3p and mmu-let-7d-5p were upregulated, whereas mmu-miR-329-3p was down-regulated during infection. Functional assays demonstrated that overexpression of miR-329, but not miR-184-3p or miR-let-7d-5p, increased HSV-1 viral entry and replication in a dose-dependent manner. In contrast, miR-329 inhibition reversed these effects, suggesting its role as a pro-viral miRNA. Increased plaque formation and viral gB expression further confirmed miR-329's pro-viral role.

Conclusions

Our findings suggest that miR-329 functions as a pro-viral miRNA by disrupting TLR9 signaling, thus facilitating HSV-1 replication. Inhibition of miR-329 enhances TLR9-mediated antiviral responses, highlighting the potential of targeting host miRNAs as a novel therapeutic strategy for managing viral keratitis.

SARS-CoV-2 S protein disrupts the formation of ISGF3 complex through conserved S2 subunit to antagonize type I interferon response

Viral immunosuppression substantially affects the host immune response of infected patients and the protective efficacy of vaccines. Here, we found that the spike (S) protein, the major vaccine antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), strongly suppresses host innate immunity by inhibiting interferon-stimulated gene (ISG) expression through both S1 and S2 subunits. Mechanistically, the S protein inhibited the formation of the classic interferon-stimulated gene factor 3 (ISGF3) complex composed of STAT1, STAT2, and IRF9 by competing with STAT2 for binding to IRF9, thereby impeding the transcription of ISGs. A strong interaction between S and the STAT1/STAT2 proteins further traps the ISGF3 complex in the endoplasmic reticulum and hinders the nuclear translocation of ISGF3. Notably, the interferon-inhibitory mechanism of the S protein was universal among SARS-CoV-2 variants and other human coronaviruses, including SARS-CoV, Middle East respiratory syndrome coronavirus (MERS-CoV), human coronavirus 229E (HCoV-229E), human coronavirus NL63 (HCoV-NL63), and human coronavirus HKU1 (HCoV-HKU1), through the most evolutionarily conserved region of S2 subunit. Taken together, the findings of this study reveal a new mechanism by which the coronavirus S protein attenuates the host antiviral immune response and provides new insights into the proper design of coronavirus S-based vaccines to prevent immunosuppressive effects.

IMPORTANCE

This study unveils a new mechanism by which the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein attenuates the host's antiviral immune response. The interferon-inhibitory mechanism of the S protein was universal among SARS-CoV-2 variants and other human coronaviruses, including SARS-CoV, MERS-CoV, HCoV-229E, HCoV-NL63, and HCoV-HKU1, through conserved S2 domains. Our study expands the understanding of SARS-CoV-2 and other human coronaviruses in evading antiviral immune strategies, which is very important for the design and optimization of vaccine antigens, thus providing a theoretical basis for human anti-coronavirus immunity and understanding the interaction between the host and coronavirus.

The Role of Sustained Type I Interferon Secretion in Chronic HIV Pathogenicity: Implications for Viral Persistence, Immune Activation, and Immunometabolism

Human immunodeficiency virus (HIV) infection induces chronic immune activation by stimulating both the innate and adaptive immune systems, resulting in persistent inflammation and immune cell exhaustion. Of note, the modulation of cytokine production and its release can significantly influence the immune response. Type I interferons (IFN-Is) are cytokines that play a crucial role in innate immunity due to their potent antiviral effects, regulation of IFN-stimulated genes essential for viral clearance, and the initiation of both innate and adaptive immune responses. Thus, an understanding of the dual role of IFN-I (protective versus harmful) during HIV-1 infections and elucidating its contributions to HIV pathogenesis is crucial for advancing HIV therapeutic interventions. This review therefore delves into the intricate involvement of IFN-I in both the acute and chronic phases of HIV infection and emphasizes its impact on viral persistence, immune activation, and immunometabolism in treated HIV-infected individuals.

Transformation of brain myeloid cell populations by SIV in rhesus macaques revealed by multiomics

The primary immune constituents in the brain, microglia and macrophages, are the target for HIV in people and simian immunodeficiency virus (SIV) in nonhuman primates. This infection can lead to neurological dysfunction, known as HIV-associated neurocognitive disorder (HAND). Given the gaps in our knowledge on how these cells respond in vivo to CNS infection, we perform single-cell multiomic sequencing, including gene expression and ATAC-seq, on myeloid cells from the brains of rhesus macaques with SIV-induced encephalitis (SIVE) as well as uninfected controls. We find that SIVE significantly changes the myeloid cell populations. In SIVE, microglia-like cells express high levels of chemoattractants capable of recruiting highly activated CAM-like cells to the site of infection/inflammation. A unique population of microglia-like cells is found in which the chromatin accessibility of genes diverges from their RNA expression. Additionally, we observe a dramatic shift of upstream gene regulators and their targets in brain myeloid cells during SIVE. This study further uncovers the transcriptome, gene regulatory events, and potential roles of different brain myeloid phenotypes in SIVE. This might deepen the understanding of SIVE/HIVE and enlighten the therapeutic development.

m5C methylation modification may be an accomplice in colorectal cancer escaping from anti-tumor effects of innate immunity-type I/III interferon

Colorectal cancer (CRC) is one of the most prevalent malignant tumors in the world, and its occurrence and development are closely related to the complex immune regulatory mechanisms. As the first barrier of the body's defense, innate immunity plays a key role in tumor immune surveillance and anti-tumor response, in which type I/III interferon (IFN) is an important mediator with significant antiviral and anti-tumor functions. 5-methylcytosine (m5C) modification of RNA is a key epigenetic regulation that promotes the expression of CRC oncogenes and immune-related genes. It can enhance the proliferation, migration, and invasion of tumor cells by affecting mRNA stability, translation efficiency, and nuclear export. In addition, m5C modification modulates the activity of innate immune signaling pathways and inhibits interferon production and function, further helping tumor cells evade immune surveillance. However, there are insufficient elucidations on the interaction between m5C modification and innate immunity in CRC. In this study, the mechanism of interferon I/III in colorectal cancer was systematically reviewed and explored. This work focused on how m5C modification promotes tumor immune escape by affecting the interferon signaling pathway, thereby providing new diagnostic markers and therapeutic targets for clinical use, and enhancing the immunotherapy efficacy.

Acidic polysaccharide from the edible insect Protaetia brevitarsis seulensis activates antiviral immunity to suppress norovirus infection

Edible insects are gaining attention as potential nutraceutical sources with immunomodulatory properties. This study reports purification and structural characterization of polysaccharides from Protaetia brevitarsis seulensis larvae (PBSL) with antiviral activity against murine norovirus. Four polysaccharide fractions purified from PBSL water extracts exhibited varying molecular weights (458.5-627.3 kDa) and monosaccharide compositions, including glucose (42.4-99.2 %), galactose (5.9-13.9 %), rhamnose (0.7-18.7 %), arabinose (3.8-5.4 %), and glucuronic acid (0-15.3 %). The immunomodulatory activity, assessed by interferon-β (IFN-β) production, positively correlated with higher galactose, mannose, rhamnose, and uronic acid contents. Among the fractions, PBS-P, eluted with 0.5 M NaCl, demonstrated superior in vitro antiviral activity with IFN-β production exceeding 8-fold compared to other fractions and 82-fold higher than PBSL water extract, confirming it as the main antiviral active component. Structural analysis revealed PBS-P backbone consisted of α-(1 → 4)-D-Glcp, α-(1 → 4,6)-D-Glcp, α-(1 → 4)-D-GlcpA, α-(1 → 3)-D-Galp and α-(1 → 4)-D-Manp residues, and branched chains of α-D-Glcp-(1→, and α-L-Arap-(1 → 2)-α-L-Rhap-(1 → residues. PBS-P suppressed norovirus replication by stimulating IFN-β, TNF-α, and activating NF-κB, STAT1/2, and TBK1-IRF3 pathways, and its oral administration reduced viral loads in infected mice intestines. This study provides the first report on the detailed structural feature of polysaccharide from an edible insect and its antiviral mechanism, highlighting its potential as a new antiviral agent.

FAT1 knockdown enhances the CSC properties of HNSCC through p-CaMKII-mediated inactivation of the IFN pathway

FAT atypical cadherin 1 (FAT1), which encodes an atypical cadherin-coding protein, has a high mutation rate and is commonly regarded as a tumor suppressor gene in head and neck squamous cell carcinoma (HNSCC). Nonetheless, the potential regulatory mechanisms by which FAT1 influences the progression of HNSCC remain unresolved. In this context, we reported that FAT1 was downregulated in tumor tissues/cells compared with normal tissues/cells and that it was correlated with the clinicopathological features and prognosis of HNSCC. Knockdown of FAT1 enhanced cancer stem cell (CSC) properties and decreased the percentage of apoptotic tumor cells. Mechanistically, FAT1 knockdown increased the phosphorylation levels of Ca2+/calmodulin-dependent protein kinase II (CaMKII), subsequently resulting in diminished interaction between phosphorylated STAT1 and interferon regulatory factor 9 (IRF9), which inactivated the interferon pathway and facilitated the adoption of the malignant phenotype of HNSCC cells. The overexpression of STAT1 and IRF9 alleviated the malignant behavior caused by FAT1 inhibition. In summary, our study reveals the role of FAT1 in suppressing the CSC properties of HNSCC via the CaMKII/STAT1/IRF9 pathway, and that targeting FAT1 might be a promising treatment for HNSCC.

Cancer-specific innate and adaptive immune rewiring drives resistance to PD-1 blockade in classic Hodgkin lymphoma

Hodgkin Reed-Sternberg (HRS) cells of classic Hodgkin lymphoma (cHL), like many solid tumors, elicit ineffective immune responses. However, patients with cHL are highly responsive to PD-1 blockade, which largely depends on HRS cell-specific retention of MHC class II and implicates CD4+ T cells and additional MHC class I-independent immune effectors. Here, we utilize single-cell RNA sequencing and spatial analysis to define shared circulating and microenvironmental features of the immune response to PD-1 blockade in cHL. Compared with non-responders, responding patients have more circulating CD4+ naïve and central memory T cells and B cells, as well as more diverse CD4+ T cell and B cell receptor repertoires. Importantly, a population of circulating and tumor-infiltrating IL1β+ monocytes/macrophages is detectable in patients with cHL but not healthy donors, and a proinflammatory, tumor-promoting signature of these circulating IL1β+ monocytes is associated with resistance to PD-1 blockade in cHL. Altogether, our findings reveal extensive immune rewiring and complementary roles of CD4+ T cells, B cells and IL1β+ monocytes in the response to PD-1 blockade and suggest that these features can be captured with a peripheral blood test.

Exploring emerging JAK inhibitors in the treatment of Aicardi-Goutières syndrome

INTRODUCTION

Aicardi-Goutières syndrome (AGS) is a genetically heterogeneous monogenic autoinflammatory disorder classified as an 'interferonopathy'. Nine genes have been implicated in AGS, encoding proteins involved in nucleic acid clearance, repair, sensing, or histone pre-mRNA processing. Dysregulation in these pathways leads to excessive type I interferon production, the primary driver of the disease. AGS typically presents with early-life neurological regression, followed by stabilization with varying degrees of neurological impairment and common extra-neurological features, such as chilblains. Advances in understanding AGS pathogenesis have enabled the development of new therapies, with JAK inhibitors emerging as the most studied option for reducing interferon-mediated effects.

AREAS COVERED

This review discusses the clinical features, genetic basis, and molecular pathways of AGS while tracing the evolution of its therapeutic strategies. Particular emphasis is placed on JAK inhibitors, which target proteins activated by type I interferons, providing a novel direction in treatment.

EXPERT OPINION

Inhibitors effectively reduce extra-neurological symptoms in AGS, though their impact on neurological outcomes remains unclear. The unknown natural history of AGS limits treatment evaluation. Despite growing insights, key aspects of pathogenesis and treatment optimization - including timing, administration, and long-term effects - remain unresolved, highlighting the need for further research.

Recent updates of interferon-derived myxovirus resistance protein A as a biomarker for acute viral infection

BACKGROUND

Antibiotic resistance (AMR) remains a global public health threat with a high burden in sub-Saharan countries. The overuse of antimicrobials in the clinical setting is the main factor for the spread of antibiotic resistance. Diagnostic uncertainty in differentiating between bacterial and viral infections is the major contributor to antimicrobial overuse. The available biomarkers lack specificity in guiding clinicians to make antibiotic decisions and only estimate bacterial infection.

MAIN BODY

Myxovirus resistance (Mx) proteins are a type of interferon (IFN)-inducible protein that belongs to the dynamin superfamily of large guanine triphosphates (GTPases) involved in broad antiviral responses. Myxovirus resistance protein A (MxA) is a host-derived biomarker with antiviral properties against various viruses. It is induced by IFN I and IFN III as part of the innate immune response. Its basal level is < 15 ng/ml and elevated levels are detectable 1-2 h after IFN induction and remain detectable in serum up to 10 days after viral infection. Increased levels in the blood are associated with viral infection and remain low during bacterial infections. This biomarker showed promising performance in diagnosing undifferentiated febrile patients with respiratory tract infections. In this review, we discuss the role of Mx proteins, specifically MxA, in diagnosing acute viral infections, including how they are induced and their potential as diagnostic tools.

METHODS

A comprehensive electronic search was conducted in Scopus and Medline (using the PubMed interface) regarding myxovirus resistance protein A as a biomarker for acute viral infection. In the search strategy, English language was used without date restriction. Manual search was also performed when appropriate.

CONCLUSIONS

Elevated MxA combined with other biomarkers, such as CRP and PCT, is a promising tool for identifying patients with viral infections. Therefore, incorporating MxA in the existing point of care formats help to improve the antibiotic stewardship programs and future randomized controlled trials are recommended to evaluate its utility in medical practice.

Dietary Modulation of the Immune System

Recent insights into the influence of nutrition on immune system components have driven the development of dietary strategies targeting the prevention and management of major metabolic-inflammatory diseases. This review summarizes the bidirectional relationship between nutrition and immunocompetence, beginning with an overview of immune system components and their functions. It examines the effects of nutritional status, dietary patterns, and food bioactives on systemic inflammation, immune cell populations, and lymphoid tissues, as well as their associations with infectious and chronic disease pathogenesis. The mechanisms by which key nutrients influence immune constituents are delineated, focusing on vitamins A, D, E, C, and B, as well as minerals including zinc, iron, and selenium. Also highlighted are the immunomodulatory effects of polyunsaturated fatty acids as well as bioactive phenolic compounds and probiotics, given their expanding relevance. Each section addresses the implications of nutritional and nutraceutical interventions involving these nutrients within the broader context of major infectious, metabolic, and inflammatory diseases. This review further underscores that, while targeted nutrient supplementation can effectively restore immune function to optimal levels, caution is necessary in certain cases, as it may increase morbidity in specific diseases. In other instances, dietary counseling should be integrated to ensure that therapeutic goals are achieved safely and effectively.

Acute effects of TLR3 agonist Poly(I:C) on bone marrow hematopoietic progenitor cells in mice

Hematopoietic progenitor cells (HPCs) in bone marrow with limited abilities for self-renewal and differentiation continuously supply hematopoietic cells through life. When suffering infection or inflammation, HPCs will actively proliferate to provide differentiated hematopoietic cells to maintain hematopoietic homeostasis. Poly(I:C), an agonist of TLR3, can specifically activate Type I interferon (IFN-I) signaling which exerts anti-inflammatory effects and influence hematopoiesis after infection. However, the effects of Poly(I:C)-induced IFN-I on the bone marrow hematopoietic system still deserve attention. In this study, our results revealed the efficacy of the IFN-I model, with a remarkably decrease in HPCs and a sharp elevation in LSKs numbers after single dose of Poly(I:C) injection. Apoptotic ratios of HPCs and LSKs significantly increased 48 h after Poly(I:C) treatment. Application of Poly(I:C) prompted the transition of HPCs and LSKs from G0 to G1 phases, potentially leading to the accelerated exhaustion of HPCs. From the cobblestone area-forming cell (CAFC) assay, we speculate that Poly(I:C) impairs the differentiation capacity of HPCs as well as their colony-forming ability. RT-qPCR and immunohistochemistry revealed significant upregulation of IFN-I associated genes and proteins following Poly(I:C) treatment. In conclusion, a single dose of Poly(I:C) induced an acute detrimental effect on HPCs within 48 h potentially due to TLR3 engagement. This activation cascaded into a robust IFN-I response emanating from the bone marrow, underscoring the intricate immunological dynamics at play following Poly(I:C) intervention.

Recent Advances in Immunological Landscape and Immunotherapeutic Agent of Nipah Virus Infection

Over the last two decades, the Nipah virus (NiV) emerged as a highly lethal zoonotic pathogen to humans. Outbreaks occurred occasionally in South and Southeast Asia. Therefore, a safe and effective vaccine against the virus is needed to fight against the deadly virus. Understanding the immunological landscape during this lethal virus infection is necessary in this direction. However, we found scattered information on the immunological landscape of the virus's reservoir, as well as hosts such as humans and livestock. The review provides a recent understanding of the immunological landscape of the virus's reservoir, human hosts, monoclonal antibodies, and vaccines for NiV infection. To describe the immunological landscape, we divided our review article into some points. Firstly, we illustrated bats' immune response as a reservoir during the NiV infection. Secondly, we illustrated an overview of the molecular mechanisms underlying the immune response to the NiV infection, various immune cells, humans' innate immune response, adaptive immunity, and the landscape of cytokines and chemokines. We also discussed INF escape, NET evasion, the T cell landscape, and the B cell landscape during virus infection. Thirdly, we also demonstrated the potential monoclonal antibody therapeutics, and vaccines. Finally, neutralizing antibodies (nAbs) of NiV and potentially other therapeutic strategies were discussed. The review will help researchers for better understanding the immunological landscape, mAbs, and vaccines, enabling them to develop their next-generation versions.

A multi-trait epigenome-wide association study identified DNA methylation signature of inflammation among men with HIV

Inflammation underlies many conditions causing excess morbidity and mortality among people with HIV (PWH). A handful of single-trait epigenome-wide association studies (EWAS) have suggested that inflammation is associated with DNA methylation (DNAm) among PWH. Multi-trait EWAS may further improve statistical power and reveal pathways in common between different inflammatory markers. We conducted single-trait EWAS of three inflammatory markers (soluble CD14, D-dimers and interleukin-6) in the Veterans Aging Cohort Study (n = 920). The study population was all male PWH with an average age of 51 years, and 82.3% self-reported as Black. We then applied two multi-trait EWAS methods-CPASSOC and OmniTest-to combine single-trait EWAS results. CPASSOC and OmniTest identified 189 and 157 inflammation-associated DNAm sites, respectively, of which 112 overlapped. Among the identified sites, 56% were not significant in any single-trait EWAS. Top sites were mapped to inflammation-related genes including IFITM1, PARP9 and STAT1. These genes were significantly enriched in pathways such as "type I interferon signaling" and "immune response to virus." We demonstrate that multi-trait EWAS can improve the discovery of inflammation-associated DNAm sites, genes and pathways. These DNAm sites might hold the key to addressing persistent inflammation in PWH.

Crosstalk and Prospects of TBK1 in Inflammation

BACKGROUND

TANK-binding kinase 1 (TBK1) is a pivotal mediator of innate immunity, activated by receptors such as mitochondrial antiviral signaling protein (MAVS), stimulator of interferon genes (STING), and TIR-domain-containing adaptor inducing interferon-β (TRIF). It modulates immune responses by exerting influence on the type I interferons (IFN-Is) signaling and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways, Over the past few years, TBK1 multifaceted role in both immune and inflammatory responses is increasingly recognized.

METHODS AND RESULTS

This review aims to scrutinize how TBK1 operates within the NF-κB pathway and the interferon regulatory transcription factor 3 (IRF3)-dependent IFN-I pathways, highlighting the kinases and other molecules involved in these processes. This analysis reveals the distinctive characteristics of TBK1's involvement in these pathways. Furthermore, it has been observed that the role of TBK1 in exerting anti-inflammatory or pro-inflammatory effects is contingent upon varying pathological conditions, indicating a multifaceted role in immune regulation.

DISCUSSION

TBK1's evolving role in various diseases and the potential of TBK1 inhibitors as therapeutic agents are explored. Targeting TBK1 may provide new strategies for treating inflammatory disorders and autoimmune diseases associated with IFN-Is, warranting further investigation.

Recent Advances in Designing Adeno-Associated Virus-Based Vaccines Against Viral Infections

Over 80% of the world's deadliest pandemics are caused by viral infections, and vaccination remains the most effective way to prevent these infections from spreading. Since the discovery of the first vaccine over two centuries ago, several vaccine design technologies have been developed. Next-generation vaccines, based on mRNA and viral vector technologies, have recently emerged as alternatives to traditional vaccines. Adenoviral vector-based vaccines against coronavirus disease 2019 have demonstrated a more sustained antibody response as compared to mRNA vaccines. However, this has not been without complications, with a few cases of severe adverse events identified in vaccinated individuals, and the underlying mechanism is the subject of intense investigation. Adeno-associated viral vectors induce a weaker cellular immune response compared to adenoviral vectors, and it is mainly for this reason that there has been a diminished interest in exploring them as a vaccine platform until recently. This review will discuss recent developments and the potential of adeno-associated viral vectors as anti-viral vaccines.

Transformation of brain myeloid cell populations by SIV in rhesus macaques revealed by multiomics

The primary immune constituents in the brain, microglia and macrophages, are the target for HIV in people and simian immunodeficiency virus (SIV) in nonhuman primates. This infection can lead to neurological dysfunction, known as HIV-associated neurocognitive disorder (HAND). Given the gaps in our knowledge on how these cells respond in vivo to CNS infection, we performed single-cell multiomic sequencing, including gene expression and ATAC-seq, on myeloid cells from the brains of rhesus macaques with SIV-induced encephalitis (SIVE) as well as uninfected controls. We found that the myeloid cell populations were significantly changed by SIVE. In SIVE microglia-like cells express high levels of chemoattractants capable of recruiting highly activated CAM-like cells to the site of infection/inflammation. A unique population of microglia-like cells was found in which the chromatin accessibility of genes diverged from their RNA expression. Additionally, we observed a dramatic shift of upstream gene regulators and their targets in brain myeloid cells during SIVE. In summary, this study further uncovers the transcriptome, gene regulatory events and potential roles of different brain myeloid phenotypes in SIVE.

Interferon alpha-2b treatment for exophytic nasal papillomas and human papillomavirus infection

OBJECTIVES

Exophytic Sinonasal Papilloma (ESP) is a benign tumor of the sinonasal tract. Complete surgical excision by endoscopic surgery is the treatment of choice. However, a high recurrence rate (36% at 5-year follow-up) is associated with this method, which may indicate the presence of microorganisms such as Human Papillomavirus (HPV). It is important to note that the standard treatment for ESP does not include antiviral drugs. In our study, we are testing the effectiveness of an interferon-containing drug in reducing recurrence and postoperative reactions in patients with ESP.

METHODS

We included 78 patients aged 23-83 years with a confirmed diagnosis of ESP by rhinoscopy and nasal endoscopy and a positive PCR test for HPV in nasal scrapings. To compare the results, we divided the patients into main and control groups. The main group received recombinant human interferon after surgery, while the control group did not receive the drug. We performed a statistical analysis to compare the proportion of patients without reactive manifestations at different stages of the postoperative period, as well as to compare the proportion of patients with recurrent ESP at certain stages of observation.

RESULTS

The introduction of recombinant human interferon accelerated the resolution of postoperative reactions and promoted the healing of the nasal mucosa after surgical removal of the ESP. We also found a statistically significant association between treatment with recombinant interferon and a reduction in the recurrence rate of ESP.

CONCLUSION

According to the results of the study, it was found that in the main group of patients who received rhIFN-α2b (recombinant human Interferon alpha 2b) in the postoperative period, the frequency of relapses of ESP and the time of postoperative recovery were significantly lower than in patients in the control group who did not take the drug.

LEVEL OF EVIDENCE

Cohort Study.

Xiaowugui decoction alleviates experimental rheumatoid arthritis by suppressing Rab5a-mediated TLR4 internalization in macrophages

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by exacerbated synovial inflammation and joint destruction. Recent studies suggest toll-like receptor 4 (TLR4) internalization facilitate inflammatory response of macrophage. The role of TLR4 internalization in the pathogenesis of RA is unknown.

PURPOSE

To investigate the role and mechanism of TLR4 internalization in macrophage inflammatory response of RA and explore whether TLR4 internalization mediates the anti-arthritic effect of Xiaowugui (XWG) decoction, a patented herbal formula used in China.

METHODS

The co-expression of TLR4 and the internalization marker, early endosome antigen 1 (EEA1), in the synovial samples of RA patients and joint tissue of collagen-induced arthritis (CIA) mice, were evaluated using immunofluorescence. The effect of Rab5a-mediated early internalization of TLR4 on the activation induced by lipopolysaccharide (LPS) in RAW264.7 cells was investigated using small interfering RNAs that act against Rab5a. CIA was induced in Rab5a-/- mice to evaluate the role of Rab5a in vivo. The disease progression and expression of Rab5a and TLR4 in the joint tissue were evaluated in CIA mice treated with XWG. Inflammatory factors production, TLR4 internalization, and activation of downstream signaling pathways were examined in RAW264.7 cells treated with XWG in vitro.

RESULTS

The co-expression and co-localization of TLR4 and EEA1 were elevated in the synovial samples of RA patients and joint tissue of CIA mice. Pharmaceutical inhibition of TLR4 internalization reduced macrophages inflammatory responses induced by LPS. The co-expression and co-localization of Rab5a and TLR4 were significantly increased in macrophages treated with LPS. Silencing Rab5a reduced LPS-induced TLR4 internalization, inflammatory factors production, and phosphorylation of Jun N-terminal kinases (JNK) and p65. Genetic deletion of Rab5a inhibited TLR4 internalization and the development of arthritis in vivo. The co-expression of TLR4 and Rab5a was also elevated in the synovial samples of RA patients. XWG treatment of mice with CIA alleviated arthritis and reduced the co-expression of Rab5a and TLR4 in the joint tissue. XWG treatment of macrophage inhibited LPS-induced IL-6 and TNF-α production, co-expression of Rab5a and TLR4, and phosphorylation of JNK and p65.

CONCLUSIONS

Our findings highlight the pathogenic role of TLR4 internalization in patients with RA and identify a novel Rab5a-dependent internalization pathway that promotes macrophage inflammatory response. XWG treatment demonstrated outstanding therapeutic effects in experimental arthritis, and targeting the Rab5a-mediated internalization of TLR4 may be the main underlying mechanism.

TBK1 is paradoxical in tumor development: a focus on the pathway mediating IFN-I expression

TANK-binding kinase 1 (TBK1) is a member of the IKK family and plays a crucial role in the activation of non-canonical NF-κB signaling and type I interferon responses. The aberrant activation of TBK1 contributes to the proliferation and survival of various types of tumor cells, particularly in specific mutational or tumorous contexts. Inhibitors targeting TBK1 are under development and application in both in vivo and in vitro settings, yet their clinical efficacy remains limited. Numerous literatures have shown that TBK1 can exhibit both tumor promoting and tumor inhibiting effects. TBK1 acts as a pivotal node within the innate immune pathway, mediating anti-tumor immunity through the activation of innate immune responses. Facilitating interferon-I (IFN-I) production represents a critical mechanism through which TBK1 bridges these processes. IFN has been shown to exert both beneficial and detrimental effects on tumor progression. Hence, the paradoxical role of TBK1 in tumor development may necessitate acknowledgment in light of its downstream IFN-I signaling cascade. In this paper, we review the signaling pathways mediated by TBK1 in various tumor contexts and summarize the dual roles of TBK1 and the TBK1-IFN pathways in both promoting and inhibiting tumor progression. Additionally, we highlight the significance of the TBK1-IFN pathway in clinical therapy, particularly in the context of immune response. We anticipate further advancements in the development of TBK1 inhibitors as part of novel cancer treatment strategies.

Determinants of pegivirus persistence, cross-species infection, and adaptation in the laboratory mouse

Viruses capable of causing persistent infection have developed sophisticated mechanisms for evading host immunity, and understanding these processes can reveal novel features of the host immune system. One such virus, human pegivirus (HPgV), infects ~15% of the global human population, but little is known about its biology beyond the fact that it does not cause overt disease. We passaged a pegivirus isolate of feral brown rats (RPgV) in immunodeficient laboratory mice to develop a mouse-adapted virus (maPgV) that established persistent high-titer infection in a majority of wild-type laboratory mice. maRPgV viremia was detected in the blood of mice for >300 days without apparent disease, closely recapitulating the hallmarks of HPgV infection in humans. We found a pro-viral role for type-I interferon in chronic infection; a lack of PD-1-mediated tolerance to PgV infection; and multiple mechanisms by which PgV immunity can be achieved by an immunocompetent host. These data indicate that the PgV immune evasion strategy has aspects that are both common and unique among persistent viral infections. The creation of maPgV represents the first PgV infection model in wild-type mice, thus opening the entire toolkit of the mouse host to enable further investigation of this persistent RNA virus infections.

UL56 Is Essential for Herpes Simplex Virus-1 Virulence In Vivo but Is Dispensable for Induction of Host-Protective Immunity

Herpes simplex virus-1 (HSV-1) is common and can cause significant disease in humans. Unfortunately, efforts to develop effective vaccines against HSV-1 have so far failed. A detailed understanding of how the virus infects its host and how the host mounts potent immune responses against the virus may inform new vaccine approaches. Here, using a zosteriform mouse model, we examined how the HSV-1 gene UL56 affects the ability of the virus to cause morbidity and generate protective immunity. A UL56 deletion mutant, ΔUL56, was derived from the wild-type HSV-1 strain SC16, alongside a revertant strain in which UL56 was reintroduced in ΔUL56. In vitro, the three virus strains replicated in a similar manner; however, in vivo, only the wild type and the revertant strains caused shingles-like skin lesions and death. Mice previously infected with ΔUL56 became resistant to a lethal challenge with the wild-type SC16. The protective immunity induced by ΔUL56 was independent of IL-1, IL-33, and IL-36 signaling through IL-1RAP. Both skin and intramuscular ΔUL56 inoculation generated protective immunity against a lethal SC16 challenge. After 6 months, female mice remained resistant to infection, while male mice exhibited signs of declining protection. Our data demonstrate that UL56 is important for the ability of HSV-1 to spread within the infected host and that a ∆UL56 strain elicits an effective immune response against HSV-1 despite this loss of virulence. These findings may guide further HSV-1 vaccine development.

Type I Interferon Activates PD-1 Expression through Activation of the STAT1-IRF2 Pathway in Myeloid Cells

PD-1 (Programmed cell death protein 1) regulates the metabolic reprogramming of myeloid-derived suppressor cells and myeloid cell differentiation, as well as the type I interferon (IFN-I) signaling pathway in myeloid cells in the tumor microenvironment. PD-1, therefore, is a key inhibitory receptor in myeloid cells. However, the regulation of PD-1 expression in myeloid cells is unknown. We report that the expression level of PDCD1, the gene that encodes the PD-1 protein, is positively correlated with the levels of IFNB1 and IFNAR1 in myeloid cells in human colorectal cancer. Treatment of mouse myeloid cell lines with recombinant IFNβ protein elevated PD-1 expression in myeloid cells in vitro. Knocking out IFNAR1, the gene that encodes the IFN-I-specific receptor, diminished the inductive effect of IFNβ on PD-1 expression in myeloid cells in vitro. Treatment of tumor-bearing mice with a lipid nanoparticle-encapsulated IFNβ-encoding plasmid (IFNBCOL01) increased IFNβ expression, resulting in elevated PD-1 expression in tumor-infiltrating myeloid cells. At the molecular level, we determined that IFNβ activates STAT1 (signal transducer and activator of transcription 1) and IRFs (interferon regulatory factors) in myeloid cells. Analysis of the cd279 promoter identified IRF2-binding consensus sequence elements. ChIP (chromatin immunoprecipitation) analysis determined that the pSTAT1 directly binds to the irf2 promoter and that IRF2 directly binds to the cd279 promoter in myeloid cells in vitro and in vivo. In colon cancer patients, the expression levels of STAT1, IRF2 and PDCD1 are positively correlated in tumor-infiltrating myeloid cells. Our findings determine that IFNβ activates PD-1 expression at least in part by an autocrine mechanism via the stimulation of the pSTAT1-IRF2 axis in myeloid cells.

Emerging paradigms: unmasking the role of oxidative stress in HPV-induced carcinogenesis

The contribution of the human papillomavirus (HPV) to cancer is significant but not exclusive, as carcinogenesis involves complex mechanisms, notably oxidative stress. Oxidative stress and HPV can independently cause genome instability and DNA damage, contributing to tumorigenesis. Oxidative stress-induced DNA damage, especially double-strand breaks, aids in the integration of HPV into the host genome and promotes the overexpression of two viral proteins, E6 and E7. Lifestyle factors, including diet, smoking, alcohol, and psychological stress, along with genetic and epigenetic modifications, and viral oncoproteins may influence oxidative stress, impacting the progression of HPV-related cancers. This review highlights various mechanisms in oxidative-induced HPV-mediated carcinogenesis, including altered mitochondrial morphology and function leading to elevated ROS levels, modulation of antioxidant enzymes like Superoxide Dismutase (SOD), Glutathione (GSH), and Glutathione Peroxidase (GPx), induction of chronic inflammatory environments, and activation of specific cell signaling pathways like the Phosphoinositide 3-kinase, Protein kinase B, Mammalian target of rapamycin (PI3K/AKT/mTOR) and the Extracellular signal-regulated kinase (ERK) signaling pathway. The study highlights the significance of comprehending and controlling oxidative stress in preventing and treating cancer. We suggested that incorporating dietary antioxidants and targeting cancer cells through mechanisms involving ROS could be potential interventions to mitigate the impact of oxidative stress on HPV-related malignancies.

3-Fucosyllactose-mediated modulation of immune response against virus infection

Viral pathogens, particularly influenza and SARS-CoV-2, pose a significant global health challenge. Given the immunomodulatory properties of human milk oligosaccharides, in particular 2'-fucosyllactose and 3-fucosyllactose (3-FL), we investigated their dietary supplementation effects on antiviral responses in mouse models. This study revealed distinct immune modulations induced by 3-FL. RNA-sequencing data showed that 3-FL increased the expression of interferon receptors, such as Interferon Alpha and Beta Receptor (IFNAR) and Interferon Gamma Receptor (IFNGR), while simultaneously downregulating interferons and interferon-stimulated genes, an effect not observed with 2'-fucosyllactose supplementation. Such modulation enhanced antiviral responses in both cell culture and animal models while attenuating pre-emptive inflammatory responses. Nitric oxide concentrations in 3-FL-supplemented A549 cells and mouse lung tissues were elevated exclusively upon infection, reaching 5.8- and 1.9-fold increases over control groups, respectively. In addition, 3-FL promoted leukocyte infiltration into the site of infection upon viral challenge. 3-FL supplementation provided protective efficacy against lethal influenza challenge in mice. The demonstrated antiviral efficacy spanned multiple influenza strains and extended to SARS-CoV-2. In conclusion, 3-FL is a unique immunomodulator that helps protect the host from viral infection while suppressing inflammation prior to infection.

Hepatocytes and the art of killing Plasmodium softly

The Plasmodium parasites that cause malaria undergo asymptomatic development in the parenchymal cells of the liver, the hepatocytes, prior to infecting erythrocytes and causing clinical disease. Traditionally, hepatocytes have been perceived as passive bystanders that allow hepatotropic pathogens such as Plasmodium to develop relatively unchallenged. However, now there is emerging evidence suggesting that hepatocytes can mount robust cell-autonomous immune responses that target Plasmodium, limiting its progression to the blood and reducing the incidence and severity of clinical malaria. Here we discuss our current understanding of hepatocyte cell-intrinsic immune responses that target Plasmodium and how these pathways impact malaria.

Grainyhead-like-2, an epithelial master programmer, promotes interferon induction and suppresses breast cancer recurrence

Type-I and -III interferons play a central role in immune rejection of pathogens and tumors, thus promoting immunogenicity and suppressing tumor recurrence. Double strand RNA is an important ligand that stimulates tumor immunity via interferon responses. Differentiation of embryonic stem cells to pluripotent epithelial cells activates the interferon response during development, raising the question of whether epithelial vs. mesenchymal gene signatures in cancer potentially regulate the interferon pathway as well. Here, using genomics and signaling approaches, we show that Grainyhead-like-2 (GRHL2), a master programmer of epithelial cell identity, promotes type-I and -III interferon responses to double-strand RNA. GRHL2 enhanced the activation of IRF3 and relA/NF-kB and the expression of IRF1; a functional GRHL2 binding site in the IFNL1 promoter was also identified. Moreover, time to recurrence in breast cancer correlated positively with GRHL2 protein expression, indicating that GRHL2 is a tumor recurrence suppressor, consistent with its enhancement of interferon responses. These observations demonstrate that epithelial cell identity supports interferon responses in the context of cancer.

Interleukins and interferons in mesenchymal stromal stem cell-based gene therapy of cancer

The tumor microenvironment is importantly shaped by various cytokines, where interleukins (ILs) and interferons (IFNs) shape the balance of immune activity within tumor niche and associated lymphoid organs. Their importance in activation and tuning of both innate and adaptive immune responses prompted their use in several clinical trials, albeit with limited therapeutic efficacy and risk of toxicity due to systemic administration. Increasing preclinical evidence suggests that local delivery of ILs and IFNs could significantly increase their effectiveness, while simultaneously attenuate the known side effects and issues related to their biological activity. A prominent way to achieve this is to use cell-based delivery vehicles. For this purpose, mesenchymal stromal stem cells (MSCs) are considered an almost ideal candidate. Namely, MSCs can be obtained in large quantities and from obtainable sources (e.g. umbilical cord or adipose tissue), their ex vivo expansion is relatively straightforward compared to other cell types and they possess very low immunogenicity making them suitable for allogeneic use. Importantly, MSCs have shown an intrinsic capacity to respond to tumor-directed chemotaxis. This review provides a focused and detailed discussion on MSC-based gene therapy using ILs and IFNs, engineering techniques and insights on potential future advancements.

A multi-trait epigenome-wide association study identified DNA methylation signature of inflammation among people with HIV

Inflammation underlies many conditions causing excess morbidity and mortality among people with HIV (PWH). A handful of single-trait epigenome-wide association studies (EWAS) have suggested that inflammation is associated with DNA methylation (DNAm) among PWH. Multi-trait EWAS may further improve statistical power and reveal pathways in common between different inflammatory markers. We conducted single-trait EWAS of three inflammatory markers (soluble CD14, D-dimers, and interleukin 6) in the Veteran Aging Cohort Study (n = 920). The study population was all male PWH with an average age of 51 years, and 82.3% self-reported as Black. We then applied two multi-trait EWAS methods-CPASSOC and OmniTest-to combine single-trait EWAS results. CPASSOC and OmniTest identified 189 and 157 inflammation-associated DNAm sites respectively, of which 112 overlapped. Among the identified sites, 56% were not significant in any single-trait EWAS. Top sites were mapped to inflammation-related genes including IFITM1, PARP9 and STAT1. These genes were significantly enriched in pathways such as "type I interferon signaling" and "immune response to virus". We demonstrate that multi-trait EWAS can improve the discovery of inflammation-associated DNAm sites, genes, and pathways. These DNAm sites suggest molecular mechanisms in response to inflammation associated with HIV and might hold the key to addressing persistent inflammation in PWH.

C-C motif chemokine receptor 2 and 7 synergistically control inflammatory monocyte recruitment but the infecting virus dictates monocyte function in the brain

Inflammatory monocytes (iMO) are recruited from the bone marrow to the brain during viral encephalitis. C-C motif chemokine receptor (CCR) 2 deficiency substantially reduces iMO recruitment for most, but not all encephalitic viruses. Here we show CCR7 acts synergistically with CCR2 to control this process. Following Herpes simplex virus type-1 (HSV-1), or La Crosse virus (LACV) infection, we find iMO proportions are reduced by approximately half in either Ccr2 or Ccr7 knockout mice compared to control mice. However, Ccr2/Ccr7 double knockouts eliminate iMO recruitment following infection with either virus, indicating these receptors together control iMO recruitment. We also find that LACV induces a more robust iMO recruitment than HSV-1. However, unlike iMOs in HSV-1 infection, LACV-recruited iMOs do not influence neurological disease development. LACV-induced iMOs have higher expression of proinflammatory and proapoptotic but reduced mitotic, phagocytic and phagolysosomal transcripts compared to HSV-1-induced iMOs. Thus, virus-specific activation of iMOs affects their recruitment, activation, and function.

When ASFV Infection Meets the cGAS-STING Signaling Pathway

The African swine fever virus (ASFV) has the ability to infect both wild boars and domestic pigs, regardless of their breeds or ages, often resulting in a mortality rate of 100%. Host innate immunity is the most important defense weapon against invasion of pathogenic microbial infection. cGAS-STING signaling pathway is one of the greatest discoveries of the twenty-first century, which is crucial in host's innate immune response. Recent studies have found that the interaction between cGAS/STING pathway and ASFV plays a key role during ASFV infection. At the same time, ASFV has also evolved different strategies to evade the killing of the host cGAS/STING pathway and promote its survival. Here, we review the latest progress in the interaction between ASFV infection, cGAS/STING pathways, and their related molecular mechanisms, aiming to provide new ideas for further research on the pathogenesis of ASFV, the development of vaccines and therapeutic drugs.

Type I interferon signaling, cognition and neurodegeneration following COVID-19: update on a mechanistic pathogenetic model with implications for Alzheimer's disease

COVID-19's effects on the human brain reveal a multifactorial impact on cognition and the potential to inflict lasting neuronal damage. Type I interferon signaling, a pathway that represents our defense against pathogens, is primarily affected by COVID-19. Type I interferon signaling, however, is known to mediate cognitive dysfunction upon its dysregulation following synaptopathy, microgliosis and neuronal damage. In previous studies, we proposed a model of outside-in dysregulation of tonic IFN-I signaling in the brain following a COVID-19. This disruption would be mediated by the crosstalk between central and peripheral immunity, and could potentially establish feed-forward IFN-I dysregulation leading to neuroinflammation and potentially, neurodegeneration. We proposed that for the CNS, the second-order mediators would be intrinsic disease-associated molecular patterns (DAMPs) such as proteopathic seeds, without the requirement of neuroinvasion to sustain inflammation. Selective vulnerability of neurogenesis sites to IFN-I dysregulation would then lead to clinical manifestations such as anosmia and cognitive impairment. Since the inception of our model at the beginning of the pandemic, a growing body of studies has provided further evidence for the effects of SARS-CoV-2 infection on the human CNS and cognition. Several preclinical and clinical studies have displayed IFN-I dysregulation and tauopathy in gene expression and neuropathological data in new cases, correspondingly. Furthermore, neurodegeneration identified with a predilection for the extended olfactory network furthermore supports the neuroanatomical concept of our model, and its independence from fulminant neuroinvasion and encephalitis as a cause of CNS damage. In this perspective, we summarize the data on IFN-I as a plausible mechanism of cognitive impairment in this setting, and its potential contribution to Alzheimer's disease and its interplay with COVID-19.

Human autoantibodies neutralizing type I IFNs: From 1981 to 2023

Human autoantibodies (auto-Abs) neutralizing type I IFNs were first discovered in a woman with disseminated shingles and were described by Ion Gresser from 1981 to 1984. They have since been found in patients with diverse conditions and are even used as a diagnostic criterion in patients with autoimmune polyendocrinopathy syndrome type 1 (APS-1). However, their apparent lack of association with viral diseases, including shingles, led to wide acceptance of the conclusion that they had no pathological consequences. This perception began to change in 2020, when they were found to underlie about 15% of cases of critical COVID-19 pneumonia. They have since been shown to underlie other severe viral diseases, including 5%, 20%, and 40% of cases of critical influenza pneumonia, critical MERS pneumonia, and West Nile virus encephalitis, respectively. They also seem to be associated with shingles in various settings. These auto-Abs are present in all age groups of the general population, but their frequency increases with age to reach at least 5% in the elderly. We estimate that at least 100 million people worldwide carry auto-Abs neutralizing type I IFNs. Here, we briefly review the history of the study of these auto-Abs, focusing particularly on their known causes and consequences.

Ratio of stemness to interferon signalling as a biomarker and therapeutic target of myeloproliferative neoplasm progression to acute myeloid leukaemia

Progression to aggressive secondary acute myeloid leukaemia (sAML) poses a significant challenge in the management of myeloproliferative neoplasms (MPNs). Since the physiopathology of MPN is closely linked to the activation of interferon (IFN) signalling and that AML initiation and aggressiveness is driven by leukaemia stem cells (LSCs), we investigated these pathways in MPN to sAML progression. We found that high IFN signalling correlated with low LSC signalling in MPN and AML samples, while MPN progression and AML transformation were characterized by decreased IFN signalling and increased LSC signature. A high LSC to IFN expression ratio in MPN patients was associated with adverse clinical prognosis and higher colony forming potential. Moreover, treatment with hypomethylating agents (HMAs) activates the IFN signalling pathway in MPN cells by inducing a viral mimicry response. This response is characterized by double-stranded RNA (dsRNA) formation and MDA5/RIG-I activation. The HMA-induced IFN response leads to a reduction in LSC signature, resulting in decreased stemness. These findings reveal the frequent evasion of viral mimicry during MPN-to-sAML progression, establish the LSC-to-IFN expression ratio as a progression biomarker, and suggests that HMAs treatment can lead to haematological response in murine models by re-activating dsRNA-associated IFN signalling.

Regulation of cellular senescence by innate immunity

During the COVID-19 pandemic, the interplay between the processes of immunity and senescence is drawing more and more intensive attention. SARS-CoV-2 infection induces senescence in lung cells, failure to clear infected cells and increased presence of inflammatory factors could lead to a cytokine storm and acute respiratory disease syndrome (ARDS), which together with aging and age-associated disease lead to 70% of COVID-19-related deaths. Studies on how senescence initiates upon viral infection and how to restrict excessive accumulation of senescent cells to avoid harmful inflammation are crucially important. Senescence can induce innate immune signaling, and innate immunity can engage cell senescence. Here, we mainly review the innate immune pathways, such as cGAS-STING, TLRs, NF-κB, and NLRP3 inflammasome, participating in the senescence process. In these pathways, IFN-I and inflammatory factors play key roles. At the end of the review, we propose the strategies by which we can improve the immune function and reduce inflammation based on these findings.

The crucial regulatory role of type I interferon in inflammatory diseases

Type I interferon (IFN-I) plays crucial roles in the regulation of inflammation and it is associated with various inflammatory diseases including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and periodontitis, impacting people's health and quality of life. It is well-established that IFN-Is affect immune responses and inflammatory factors by regulating some signaling. However, currently, there is no comprehensive overview of the crucial regulatory role of IFN-I in distinctive pathways as well as associated inflammatory diseases. This review aims to provide a narrative of the involvement of IFN-I in different signaling pathways, mainly mediating the related key factors with specific targets in the pathways and signaling cascades to influence the progression of inflammatory diseases. As such, we suggested that IFN-Is induce inflammatory regulation through the stimulation of certain factors in signaling pathways, which displays possible efficient treatment methods and provides a reference for the precise control of inflammatory diseases.

Discovering common pathogenetic processes between COVID-19 and tuberculosis by bioinformatics and system biology approach

Introduction

The coronavirus disease 2019 (COVID-19) pandemic, stemming from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has persistently threatened the global health system. Meanwhile, tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tuberculosis) still continues to be endemic in various regions of the world. There is a certain degree of similarity between the clinical features of COVID-19 and TB, but the underlying common pathogenetic processes between COVID-19 and TB are not well understood.

Methods

To elucidate the common pathogenetic processes between COVID-19 and TB, we implemented bioinformatics and systematic research to obtain shared pathways and molecular biomarkers. Here, the RNA-seq datasets (GSE196822 and GSE126614) are used to extract shared differentially expressed genes (DEGs) of COVID-19 and TB. The common DEGs were used to identify common pathways, hub genes, transcriptional regulatory networks, and potential drugs.

Results

A total of 96 common DEGs were selected for subsequent analyses. Functional enrichment analyses showed that viral genome replication and immune-related pathways collectively contributed to the development and progression of TB and COVID-19. Based on the protein-protein interaction (PPI) network analysis, we identified 10 hub genes, including IFI44L, ISG15, MX1, IFI44, OASL, RSAD2, GBP1, OAS1, IFI6, and HERC5. Subsequently, the transcription factor (TF)-gene interaction and microRNA (miRNA)-gene coregulatory network identified 61 TFs and 29 miRNAs. Notably, we identified 10 potential drugs to treat TB and COVID-19, namely suloctidil, prenylamine, acetohexamide, terfenadine, prochlorperazine, 3'-azido-3'-deoxythymidine, chlorophyllin, etoposide, clioquinol, and propofol.

Conclusion

This research provides novel strategies and valuable references for the treatment of tuberculosis and COVID-19.

Similarities in the induction of the intracellular pathogen response in Caenorhabditis elegans and the type I interferon response in mammals

Although the type-I interferon (IFN-I) response is considered vertebrate-specific, recent findings about the Intracellular Pathogen Response (IPR) in nematode Caenorhabditis elegans indicate that there are similarities between these two transcriptional immunological programs. The IPR is induced during infection with natural intracellular fungal and viral pathogens of the intestine and promotes resistance against these pathogens. Similarly, the IFN-I response is induced by viruses and other intracellular pathogens and promotes resistance against infection. Whether the IPR and the IFN-I response evolved in a divergent or convergent manner is an unanswered and exciting question, which could be addressed by further studies of immunity against intracellular pathogens in C. elegans and other simple host organisms. Here we highlight similar roles played by RIG-I-like receptors, purine metabolism enzymes, proteotoxic stressors, and transcription factors to induce the IPR and IFN-I response, as well as the similar consequences of these defense programs on organismal development.

The fluctuations of expression profiles of critical genes in the miRNA maturation process and pro-and anti-inflammatory cytokines in the pathogenesis and progression of multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a central nervous system disease known for immune-mediated demyelination, inflammatory, and neurodegeneration symptoms. Discovering molecular biomarkers to classify RRMS and SPMS patients, monitor the disease activity, and response to particular treatments is one area that has received notable attraction. MicroRNA (miRNA), a single-stranded non-coding RNA molecule, is a significant regulator of gene expression recruited in pathogenic mechanisms in diverse diseases, especially cancer and MS. Also, the relapsing-remitting features of MS exhibit that both inflammatory and anti-inflammatory cytokines are effective in the progression of the disease over time.

METHODS AND RESULTS

It was assessed the expression patterns of the genes (Drosha, Pasha (DGCR8), and Dicer ) encoding the critical enzymes in the processing steps of miRNA maturation and major pro-inflammatory and anti-inflammatory cytokines (IFN-α, IFN-β, and IL-6) in blood cells of 40 MS patients (two groups of 10 men and women in both clinical courses of RR and SPMS patients) in comparison with 20 healthy control group (10 males and 10 females). The highest transcription activity of Drosha was observed for RRMS patients (4.2 and 3.6-fold, respectively), and the expression ratio was down regulated in male and female patients with SPMS (3.9- and 3.1-fold, respectively). Considering the studied cytokines, the increase in expression ratio of IL-6 in SPMS patients and the decrease in transcript abundance of INF-α, and INF-β cytokines are consistent with the progression of the disease.

CONCLUSIONS

Our findings showed that the high and low transcriptional levels of the considered genes seem to be effective in the pathogenesis and progression of MS.

Synergistic Effects of Azithromycin and STING Agonist Promote IFN-I Production by Enhancing the Activation of STING-TBK1 Signaling

Background

Azithromycin (AZM) is a macrolide antibiotic that exhibits anti-inflammatory and anti-viral infection properties by enhancing type-I interferon (IFN-I) responses. The stimulator of interferon genes (STING) can directly induce IFN-I production. However, elevated IFN-I induces auto-immune phenotypes such as systemic lupus erythematosus (SLE). The effects of AZM and STING on the production of IFN-I are unclear.

Objective

Therefore, this study aims to evaluate the role of AZM and STING on IFN-I responses in macrophages.

Methods

RAW 264.7 macrophages were treated with AZM with and without a STING-agonist (DMXAA), and the maturation of macrophages was determined using flow cytometry. Gene expression and pro-inflammatory cytokines were analyzed using qPCR and ELISA, respectively. Moreover, protein expression was investigated using Western blot assays and immunofluorescence.

Results

Our results show that AZM significantly induced M1 phenotypes, promoting surface molecule expansion of CD80 and MHC-II and production of IL-6 and TNF-α cytokines on DMXAA-stimulated macrophages. Furthermore, we found that AZM-increased mRNA levels of interferon-stimulated genes (ISGs) could be due to the high expression of STNG-TBK1 signaling in the presence of DMXAA.

Conclusion

Our data suggest that AZM enhancement of IFN-I responses was STING dependent in DMXAA-stimulated macrophages. These data underline a novel approach to AZM action-mediated STING-TBK1 signaling for regulating IFN-I responses and may further augment the scientific basis and potential use of AZM in clinical applications.

Latent human herpesvirus 6 is reactivated in CAR T cells

Cell therapies have yielded durable clinical benefits for patients with cancer, but the risks associated with the development of therapies from manipulated human cells are understudied. For example, we lack a comprehensive understanding of the mechanisms of toxicities observed in patients receiving T cell therapies, including recent reports of encephalitis caused by reactivation of human herpesvirus 6 (HHV-6)1. Here, through petabase-scale viral genomics mining, we examine the landscape of human latent viral reactivation and demonstrate that HHV-6B can become reactivated in cultures of human CD4+ T cells. Using single-cell sequencing, we identify a rare population of HHV-6 'super-expressors' (about 1 in 300-10,000 cells) that possess high viral transcriptional activity, among research-grade allogeneic chimeric antigen receptor (CAR) T cells. By analysing single-cell sequencing data from patients receiving cell therapy products that are approved by the US Food and Drug Administration2 or are in clinical studies3-5, we identify the presence of HHV-6-super-expressor CAR T cells in patients in vivo. Together, the findings of our study demonstrate the utility of comprehensive genomics analyses in implicating cell therapy products as a potential source contributing to the lytic HHV-6 infection that has been reported in clinical trials1,6-8 and may influence the design and production of autologous and allogeneic cell therapies.