Lambda interferon (IFN-lambda), a type III IFN, is induced by viruses and IFNs and displays potent antiviral activity against select virus infections in vivo

Comparative transcriptome reveals EphA2 and c-Fos as key factors driving enhanced replication in high-passage porcine deltacoronavirus strain

Porcine deltacoronavirus (PDCoV), a cross-species transmissible enterovirus, frequently induces severe diarrhea and vomiting symptoms in piglets, which not only pose a significant menace to the global pig industry but also a potential public safety risk. In a previous study, we isolated a vaccine candidate, PDCoV CZ2020-P100, by passaging a parental PDCoV strain in vitro, exhibiting attenuated virulence and enhanced replication. However, the factors underlying these differences between primary and passaged strains remain unknown. In this study, we present the transcriptional landscapes of porcine kidney epithelial cells (LLC-PK1) cells infected with PDCoV CZ2020-P1 strain and P100 strain using the RNA-sequencing. We identified 105 differentially expressed genes (DEGs) in P1-infected cells and 295 DEGs in P100-infected cells. Enrichment analyses indicated that many DEGs showed enrichment in immune and inflammatory responses, with a more and higher upregulation of DEGs enriched in the P100-infected group. Notably, the DEGs were concentrated in the MAPK pathway within the P100-infected group, with significant upregulation in EphA2 and c-Fos. Knockdown of EphA2 and c-Fos reduced PDCoV infection and significantly impaired P100 replication compared to P1, suggesting a novel mechanism in which EphA2 and c-Fos are highly involved in passaged virus replication. Our findings illuminate the resemblances and distinctions in the gene expression patterns of host cells infected with P1 and P100, confirming that EphA2 and c-Fos play key roles in high-passage PDCoV replication. These results enhance our understanding of the changes in virulence and replication capacity during the process of passaging.

IFNε, IFNω and IFNλ: interferons defending the mucosa

The unconventional type I interferons IFNε and IFNω and type III interferon IFNλ are gradually emerging as tissue-specific cytokines in defence of mucosal tissues. This review provides an overview of the distinct features and functions that define these IFNs as protective factors in the respiratory, gastrointestinal and reproductive tracts, highlighting their immunoregulatory roles against pathogens while maintaining tolerance against commensal microbes. In particular, we discuss recent advances in our understanding of the constitutively expressed IFNε and its role in protecting against mucosal infections, inflammation and cancers. We identify an emerging theme for this unique cytokine as a key contributor to the 'first line of defence' against pathogens and maintenance of mucosal tissue homeostasis, primarily through its regulation of immune cell populations.

Proteomics Analysis of Duck Lung Tissues in Response to Highly Pathogenic Avian Influenza Virus

Domestic ducks (Anas platyrhynchos domesticus) are resistant to most of the highly pathogenic avian influenza virus (HPAIV) infections. In this study, we characterized the lung proteome and phosphoproteome of ducks infected with the HPAI H5N1 virus (A/duck/India/02CA10/2011/Agartala) at 12 h, 48 h, and 5 days post-infection. A total of 2082 proteins were differentially expressed and 320 phosphorylation sites mapping to 199 phosphopeptides, corresponding to 129 proteins were identified. The functional annotation of the proteome data analysis revealed the activation of the RIG-I-like receptor and Jak-STAT signaling pathways, which led to the induction of interferon-stimulated gene (ISG) expression. The pathway analysis of the phosphoproteome datasets also confirmed the activation of RIG-I, Jak-STAT signaling, NF-kappa B signaling, and MAPK signaling pathways in the lung tissues. The induction of ISG proteins (STAT1, STAT3, STAT5B, STAT6, IFIT5, and PKR) established a protective anti-viral immune response in duck lung tissue. Further, the protein-protein interaction network analysis identified proteins like AKT1, STAT3, JAK2, RAC1, STAT1, PTPN11, RPS27A, NFKB1, and MAPK1 as the main hub proteins that might play important roles in disease progression in ducks. Together, the functional annotation of the proteome and phosphoproteome datasets revealed the molecular basis of the disease progression and disease resistance mechanism in ducks infected with the HPAI H5N1 virus.

HSV-1 employs UL56 to antagonize expression and function of cGAMP channels

DNA sensing is important for antiviral immunity. The DNA sensor cGAS synthesizes 2'3'-cyclic GMP-AMP (cGAMP), a second messenger that activates STING, which induces innate immunity. cGAMP not only activates STING in the cell where it is produced but cGAMP also transfers to other cells. Transporters, channels, and pores (including SLC19A1, SLC46A2, P2X7, ABCC1, and volume-regulated anion channels (VRACs)) release cGAMP into the extracellular space and/or import cGAMP. We report that infection with multiple human viruses depletes some of these cGAMP conduits. This includes herpes simplex virus 1 (HSV-1) that targets SLC46A2, P2X7, and the VRAC subunits LRRC8A and LRRC8C for degradation. The HSV-1 protein UL56 is necessary and sufficient for these effects that are mediated at least partially by proteasomal turnover. UL56 thereby inhibits cGAMP uptake via VRAC, SLC46A2, and P2X7. Taken together, HSV-1 antagonizes intercellular cGAMP transfer. We propose that this limits innate immunity by reducing cell-to-cell communication via the immunotransmitter cGAMP.

Type III interferons in innate and adaptive immunity in the respiratory tract

Lambda interferons (IFNλs), also termed type III interferons (IFNs) or interleukins-28/29, have been in the shadow of type I IFNs for a long time. Their common induction mechanisms and signalling cascades with type I IFNs have made difficult the unwinding of their unique nonredundant functions. However, this is now changing with mounting evidence supporting a major role of IFNλs as a specialized antiviral defense system in the body, mediating protection at mucosal barrier surfaces while limiting immunopathology. Here, we review the latest progress on the complex activities of IFNλs in the respiratory tract, focusing on their multiple effects in IFNλ receptor-expressing cells, the modulation of innate and adaptive immune responses in the context of infections and respiratory diseases, and their similarities and differences with type I IFNs. We also discuss their potential in therapeutic applications and the most recent developments in that direction.

Regulation of host/pathogen interactions in the gastrointestinal tract by type I and III interferons

Interferons (IFNs) are an integral component of the host innate immune response during viral infection. Recent advances in the study of type I and III IFNs suggest that though both types counteract viral infection, type III IFNs act predominantly at epithelial barrier sites, while type I IFNs drive systemic responses. The dynamics and specific roles of type I versus III IFNs have been studied in the context of infection by a variety of enteric pathogens, including reovirus, rotavirus, norovirus, astrovirus, and intestinal severe acute respiratory syndrome coronavirus 2, revealing shared patterns of regulatory influence. An important role for the gut microbiota, including the virome, in regulating homeostasis and priming of intestinal IFN responses has also recently emerged.

Comparative single-cell RNA sequencing analysis of immune response to inactivated vaccine and natural SARS-CoV-2 infection

Uncovering the immune response to an inactivated SARS-CoV-2 vaccine (In-Vac) and natural infection is crucial for comprehending COVID-19 immunology. Here we conducted an integrated analysis of single-cell RNA sequencing (scRNA-seq) data from serial peripheral blood mononuclear cell (PBMC) samples derived from 12 individuals receiving In-Vac compared with those from COVID-19 patients. Our study reveals that In-Vac induces subtle immunological changes in PBMC, including cell proportions and transcriptomes, compared with profound changes for natural infection. In-Vac modestly upregulates IFN-α but downregulates NF-κB pathways, while natural infection triggers hyperactive IFN-α and NF-κB pathways. Both In-Vac and natural infection alter T/B cell receptor repertoires, but COVID-19 has more significant change in preferential VJ gene, indicating a vigorous immune response. Our study reveals distinct patterns of cellular communications, including a selective activation of IL-15RA/IL-15 receptor pathway after In-Vac boost, suggesting its potential role in enhancing In-Vac-induced immunity. Collectively, our study illuminates multifaceted immune responses to In-Vac and natural infection, providing insights for optimizing SARS-CoV-2 vaccine efficacy.

Beneficial and Detrimental Effects of Cytokines during Influenza and COVID-19

Cytokines are signaling molecules that play a role in myriad processes, including those occurring during diseases and homeostasis. Their homeostatic function begins during embryogenesis and persists throughout life, including appropriate signaling for the cell and organism death. During viral infections, antiviral cytokines such as interferons and inflammatory cytokines are upregulated. Despite the well-known benefits of these cytokines, their levels often correlate with disease severity, linking them to unfavorable outcomes. In this review, we discuss both the beneficial and pathological functions of cytokines and the potential challenges in separating these two roles. Further, we discuss challenges in targeting these cytokines during disease and propose a new method for quantifying the cytokine effect to limit the pathological consequences while preserving their beneficial effects.

The potential of IFN-λ, IL-32γ, IL-6, and IL-22 as safeguards against human viruses: a systematic review and a meta-analysis

Many studies have investigated the antiviral activity of cytokines, including interleukin-6 (IL-6), interleukin-22 (IL-22), interleukin-32 gamma (IL-32γ), and interferon-lambda (IFN-λ) in diverse populations. This study aims to evaluate the role of these cytokines in inhibition of various human and animal viruses when administered exogenously. A comprehensive meta-analysis and systematic review were conducted on all the relevant studies from three databases. Standard mean differences (SMDs) of overall viral inhibition were used to generate the difference in the antiviral efficacy of these cytokines between control and experimental groups. A total of 4,618 abstracts for IL-6, 3,517 abstracts for IL-22, 2,160 abstracts for IL-32γ, and 1,026 abstracts for IFN-λ were identified, and 7, 4, 8, and 35 studies were included, respectively, for each cytokine. IFN-λ (SMD = 0.9540; 95% CI: 0.69-0.22) and IL-32γ (SMD = 0.459; 95% CI: 0.02-0.90) showed the highest influence followed by IL-6 (SMD = 0.456; CI: -0.04-0.95) and IL-22 (SMD = 0.244; 95% CI: -0.33-0.81). None of the cytokines represented heterogeneity (tau² > 0), but only IFN-λ indicated the funnel plot asymmetry (p = 0.0097). Results also indicated that IFN-λ and IL-32γ are more potent antivirals than IL-6 and IL-22. The collective findings of this study emphasize that exogenously administered pro-inflammatory cytokines, specifically IFN-λ and IL-32, exhibit a significant antiviral activity, thereby underscoring them as potent antiviral agents. Nonetheless, additional research is required to ascertain their clinical utility and potential for integration into combinatorial therapeutic regimens against viral infections.

IFN-λ3 is induced by Leishmania donovani and can inhibit parasite growth in cell line models but not in the mouse model, while it shows a significant association with leishmaniasis in humans

The intracellular protozoan parasite Leishmania donovani causes debilitating human diseases that involve visceral and dermal manifestations. Type 3 interferons (IFNs), also referred to as lambda IFNs (IFNL, IFN-L, or IFN-λ), are known to play protective roles against intracellular pathogens at the epithelial surfaces. Herein, we show that L. donovani induces IFN-λ3 in human as well as mouse cell line-derived macrophages. Interestingly, IFN-λ3 treatment significantly decreased parasite load in infected cells, mainly by increasing reactive oxygen species production. Microscopic examination showed that IFN-λ3 inhibited uptake but not replication, while the phagocytic ability of the cells was not affected. This was confirmed by experiments that showed that IFN-λ3 could decrease parasite load only when added to the medium at earlier time points, either during or soon after parasite uptake, but had no effect on parasite load when added at 24 h post-infection, suggesting that an early event during parasite uptake was targeted. Furthermore, the parasites could overcome the inhibitory effect of IFN-λ3, which was added at earlier time points, within 2-3 days post-infection. BALB/c mice treated with IFN-λ3 before infection led to a significant increase in expression of IL-4 and ARG1 post-infection in the spleen and liver, respectively, and to different pathological changes, especially in the liver, but not to changes in parasite load. Treatment with IFN-λ3 during infection did not decrease the parasite load in the spleen either. However, IFN-λ3 was significantly increased in the sera of visceral leishmaniasis patients, and the IFNL genetic variant rs12979860 was significantly associated with susceptibility to leishmaniasis.

Chicken Interferon-Alpha and -Lambda Exhibit Antiviral Effects against Fowl Adenovirus Serotype 4 in Leghorn Male Hepatocellular Cells

Hydropericardium hepatitis syndrome (HHS) is primarily caused by fowl adenovirus serotype 4 (FAdV-4), causing high mortality in chickens. Although vaccination strategies against FAdV-4 have been adopted, HHS still occurs sporadically. Furthermore, no effective drugs are available for controlling FAdV-4 infection. However, type I and III interferon (IFN) are crucial therapeutic agents against viral infection. The following experiments were conducted to investigate the inhibitory effect of chicken IFN against FadV-4. We expressed recombinant chicken type I IFN-α (ChIFN-α) and type III IFN-λ (ChIFN-λ) in Escherichia coli and systemically investigated their antiviral activity against FAdV-4 infection in Leghorn male hepatocellular (LMH) cells. ChIFN-α and ChIFN-λ dose dependently inhibited FAdV-4 replication in LMH cells. Compared with ChIFN-λ, ChIFN-α more significantly inhibited viral genome transcription but less significantly suppressed FAdV-4 release. ChIFN-α- and ChIFN-λ-induced IFN-stimulated gene (ISG) expression, such as PKR, ZAP, IRF7, MX1, Viperin, IFIT5, OASL, and IFI6, in LMH cells; however, ChIFN-α induced a stronger expression level than ChIFN-λ. Thus, our data revealed that ChIFN-α and ChIFN-λ might trigger different ISG expression levels, inhibiting FAdV-4 replication via different steps of the FAdV-4 lifecycle, which furthers the potential applications of IFN antiviral drugs in chickens.

Destabilizing the genome as a therapeutic strategy to enhance response to immune checkpoint blockade: a systematic review of clinical trials evidence from solid and hematological tumors

Background: Genomic instability is increased alterations in the genome during cell division and is common among most cancer cells. Genome instability enhances the risk of initial carcinogenic transformation, generating new clones of tumor cells, and increases tumor heterogeneity. Although genome instability contributes to malignancy, it is also an "Achilles' heel" that constitutes a therapeutically-exploitable weakness-when sufficiently advanced, it can intrinsically reduce tumor cell survival by creating DNA damage and mutation events that overwhelm the capacity of cancer cells to repair those lesions. Furthermore, it can contribute to extrinsic survival-reducing events by generating mutations that encode new immunogenic antigens capable of being recognized by the immune system, particularly when anti-tumor immunity is boosted by immunotherapy drugs. Here, we describe how genome-destabilization can induce immune activation in cancer patients and systematically review the induction of genome instability exploited clinically, in combination with immune checkpoint blockade. Methods: We performed a systematic review of clinical trials that exploited the combination approach to successfully treat cancers patients. We systematically searched PubMed, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, and publication from the reference list of related articles. The most relevant inclusion criteria were peer-reviewed clinical trials published in English. Results: We identified 1,490 studies, among those 164 were clinical trials. A total of 37 clinical trials satisfied the inclusion criteria and were included in the study. The main outcome measurements were overall survival and progression-free survival. The majority of the clinical trials (30 out of 37) showed a significant improvement in patient outcome. Conclusion: The majority of the included clinical trials reported the efficacy of the concept of targeting DNA repair pathway, in combination with immune checkpoint inhibitors, to create a "ring of synergy" to treat cancer with rational combinations.

Antiviral effects of duck type I and type III interferons against Duck Tembusu virus in vitro and in vivo

Duck Tembusu Virus (DTMUV) is a newly emerging avian flavivirus that causes substantial economic losses to the duck industry in Asia by causing severe egg drop syndrome and fatal encephalitis in domestic ducks. During viral replication, host cells recognize the RNA structures produced by DTMUV, which triggers the production of interferons (IFNs) to inhibit viral replication. However, the function of duck type I and type III IFNs in inhibiting DTMUV infection remains largely unknown. In this study, we expressed and purified recombinant duck IFN-β (duIFN-β) and IFN-λ (duIFN-λ) in Escherichia coli and evaluated their antiviral activity against vesicular stomatitis virus (VSV). Furthermore, we found that both duIFN-β and duIFN-λ activated the ISRE promoter and induced the expression of ZAP, OAS, and RNaseL in duck embryo fibroblasts (DEFs). Notably, duIFN-β showed faster and more potent induction of ISGs in vitro and in vivo compared to duIFN-λ. Moreover, both duIFN-β and duIFN-λ showed high potential to inhibit DTMUV infection in DEFs, with duIFN-β demonstrating better antiviral efficacy than duIFN-λ against DTMUV in ducks. In conclusion, our results revealed that both duIFN-β and duIFN-λ can induce ISGs production and exhibit significant antiviral activity against DTMUV in vitro and in vivo, providing new insights for the development of antiviral therapeutic strategies in ducks.

Cell Intrinsic Determinants of Alpha Herpesvirus Latency and Pathogenesis in the Nervous System

Alpha herpesvirus infections (α-HVs) are widespread, affecting more than 70% of the adult human population. Typically, the infections start in the mucosal epithelia, from which the viral particles invade the axons of the peripheral nervous system. In the nuclei of the peripheral ganglia, α-HVs establish a lifelong latency and eventually undergo multiple reactivation cycles. Upon reactivation, viral progeny can move into the nerves, back out toward the periphery where they entered the organism, or they can move toward the central nervous system (CNS). This latency-reactivation cycle is remarkably well controlled by the intricate actions of the intrinsic and innate immune responses of the host, and finely counteracted by the viral proteins in an effort to co-exist in the population. If this yin-yang- or Nash-equilibrium-like balance state is broken due to immune suppression or genetic mutations in the host response factors particularly in the CNS, or the presence of other pathogenic stimuli, α-HV reactivations might lead to life-threatening pathologies. In this review, we will summarize the molecular virus-host interactions starting from mucosal epithelia infections leading to the establishment of latency in the PNS and to possible CNS invasion by α-HVs, highlighting the pathologies associated with uncontrolled virus replication in the NS.

Nuclear interferon-stimulated gene product maintains heterochromatin on the herpes simplex viral genome to limit lytic infection

Interferons (IFN) are expressed in and secreted from cells in response to virus infection, and they induce the expression of a variety of genes called interferon-stimulated genes (ISGs) in infected and surrounding cells to block viral infection and limit spread. The mechanisms of action of a number of cytoplasmic ISGs have been well defined, but little is known about the mechanism of action of nuclear ISGs. Constitutive levels of nuclear interferon-inducible protein 16 (IFI16) serve to induce innate signaling and epigenetic silencing of herpes simplex virus (HSV), but only when the HSV infected cell protein 0 (ICP0) E3 ligase, which promotes IFI16 degradation, is inactivated. In this study, we found that following IFN induction, the pool of IFI16 within the infected cell remains high and can restrict wild-type viral gene expression and replication due to both the induced levels of IFI16 and the IFI16-mediated repression of ICP0 levels. Restriction of viral gene expression is achieved by IFI16 promoting the maintenance of heterochromatin on the viral genome, which silences it epigenetically. These results indicate that a nuclear ISG can restrict gene expression and replication of a nuclear DNA virus by maintaining or preventing the removal of repressive heterochromatin associated with the viral genome.

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 Cooperation of IL-29 and PLGA Nanoparticles Improves the Protective Immunity of the gD-1 DNA Vaccine Against Herpes Simplex Virus Type 1 in Mice

In clinical practice, the low immunogenicity and low stability of the DNA plasmid vaccine candidates are two significant shortcomings in their application against infectious diseases. To overcome these two disadvantages, the plasmid expressing IL-29 (pIL-29) as a genetic adjuvant and polylactic-co-glycolic acid (PLGA) as a non-viral delivery system were used, respectively. In this study, the pIL-29 encapsulated in PLGA nanoparticles (nanoIL-29) and the pgD1 encapsulated in PLGA nanoparticles (nanoVac) were simultaneously applied to boost immunologic responses against HSV-1. We generated spherical nanoparticles with encapsulation efficiency of 75 ± 5% and sustained the release of plasmids from them. Then, Balb/c mice were subcutaneously immunized twice with nanoVac+nanoIL-29, Vac+IL-29, nanoVac, Vac, nanoIL-29, and/or IL-29 in addition to negative and positive control groups. Cellular immunity was evaluated via lymphocyte proliferation assay, cytotoxicity test, and IFN-γ, IL-4, and IL-2 measurements. Mice were also challenged with 50X LD50 of HSV-1. The nanoVac+nanoIL-29 candidate vaccine efficiently enhances CTL and Th1-immune responses and increases the survival rates by 100% in mice vaccinated by co-administration of nanoVac and nanoIL-29 against the HSV-1 challenge. The newly proposed vaccine is worth studying in further clinical trials, because it could effectively improve cellular immune responses and protected mice against HSV-1.

Interferon inhibits the release of herpes simplex virus-1 from the axons of sensory neurons

IMPORTANCE

Herpes simplex virus-1 (HSV-1) is a human pathogen known to cause cold sores and genital herpes. HSV-1 establishes lifelong infections in our sensory neurons, with no cure or vaccine available. HSV-1 can reactivate sporadically and travel back along sensory nerves, where it can form lesions in the oral and genital mucosa, eye, and skin, or be shed asymptomatically. New treatment options are needed as resistance is emerging to current antiviral therapies. Here, we show that interferons (IFNs) are capable of blocking virus release from nerve endings, potentially stopping HSV-1 transmission into the skin. Furthermore, we show that IFNγ has the potential to have widespread antiviral effects in the neuron and may have additional effects on HSV-1 reactivation. Together, this study identifies new targets for the development of immunotherapies to stop the spread of HSV-1 from the nerves into the skin.

Interferon-λ Activates a Differential Response in Peripheral Neurons That Is Effective against Alpha Herpesvirus Infections

Alpha herpesviruses (α-HV) infect host mucosal epithelial cells prior to establishing a life-long latent infection in the peripheral nervous system. The initial spread of viral particles from mucosa to the nervous system and the role of intrinsic immune responses at this barrier is not well understood. Using primary neurons cultured in compartmentalized chambers, prior studies performed on Pseudorabies virus (PRV) have demonstrated that type I and type II interferons (IFNs) induce a local antiviral response in axons via distinct mechanisms leading to a reduction in viral particle transport to the neuronal nucleus. A new class of interferons known as type III IFNs has been shown to play an immediate role against viral infection in mucosal epithelial cells. However, the antiviral effects of type III IFNs within neurons during α-HV infection are largely unknown. In this study, we focused on elucidating the antiviral activity of type III IFN against PRV neuronal infection, and we compared the interferon-stimulated gene (ISGs) induction pattern in neurons to non-neuronal cells. We found that IFN pre-exposure of both primary neurons and fibroblast cells significantly reduces PRV virus yield, albeit by differential STAT activation and ISG induction patterns. Notably, we observed that type III IFNs trigger the expression of a subset of ISGs mainly through STAT1 activation to induce an antiviral state in primary peripheral neurons.

Pathogenicity of H5N8 avian influenza virus in chickens and in duck breeds and the role of MX1 and IFN-α in infection outcome and transmission to contact birds

This study examined the pathogenicity, immunogenicity, and transmission potential of the H5N8 HPAI clade 2.3.4.4b virus in three breeds of ducks and in broiler chickens. Chickens, Muscovy, Pekin, and Mallard ducks (n = 10) received a dose of 6 log10 EID50 of HPAIV H5N8 directly. Nine contact chickens were introduced to each group on the day of infection. All infected chickens died, with MDT of 7.6 days. Muscovy and Pekin ducks died by 11.1% and 10%, respectively, with MDTs of 7 and 6 days. No Mallards died but showed more severe clinical disease than Pekin ducks. Mallards had the highest MX1 gene expression in the lung and spleen and IFN-α in the spleen. MX1 expression levels were lower in the spleen and lung of Pekin ducks, in the spleen of chickens and in the lung of Muscovy ducks than in noninfected controls. However, viral shedding was higher in ducks than in chickens and was highest in Mallards. 66.7% of chickens placed in contact with infected chickens died and 77.8% of in-contact chickens to infected three duck breeds died. In conclusion, there was a diversity in sensitivity and immunogenicity for HPAIV H5N8 among duck breeds, resulting in diverse infection outcomes and transmissibility to contacts. This study provides duck/chicken interface models for HPAIV transmission to poultry.

Characterization of Monoclonal Antibodies to Measure Cell Surface Protein Levels of Human Interferon-Lambda Receptor 1

Type III interferons (IFN-lambdas, IFN-λs) are important antiviral cytokines that can also modulate immune responses by acting through a heterodimeric receptor composed of the specific and limited expressed IFN-λR1 chain and the ubiquitous IL-10R2 chain, which is shared with IL-10 family cytokines. Conflicting data have been reported regarding which cells express the IFN-λR1 subunit and directly respond to IFN-λs. This is, in part, owing to transcript levels of the IFN-λR1 gene, IFNLR1, not always correlating with cell surface protein levels. In this study, we tested a panel of novel monoclonal antibodies (mAbs) that specifically recognize human IFN-λR1. Initially, antigen specificity was confirmed by enzyme-linked immunosorbent assay (ELISA), from which a subset of antibodies was selected for additional flow cytometry and neutralization assays. We further characterized two antibodies based on their strong ELISA binding activity (HLR1 and HLR14) and found only HLR14 could reliably detect cell surface IFN-λR1 protein on a variety of cell lines by flow cytometry. HLR14 could also detect IFN-λR1 protein on certain primary human blood cells, including plasmacytoid dendritic cells and B cells from peripheral blood. Availability of the HLR14 mAb will enable the quantification of IFN-λR1 protein levels on cells and better characterization of the cell specificity of the IFN-λ response.

Interferome signature dynamics during the anti-dengue immune response: a systems biology characterization

Dengue virus (DENV) infection manifests as a febrile illness with three distinct phases: early acute, late acute, and convalescent. Dengue can result in clinical manifestations with different degrees of severity, dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. Interferons (IFNs) are antiviral cytokines central to the anti-DENV immune response. Notably, the distinct global signature of type I, II, and III interferon-regulated genes (the interferome) remains uncharacterized in dengue patients to date. Therefore, we performed an in-depth cross-study for the integrative analysis of transcriptome data related to DENV infection. Our systems biology analysis shows that the anti-dengue immune response is characterized by the modulation of numerous interferon-regulated genes (IRGs) enriching, for instance, cytokine-mediated signaling (e.g., type I and II IFNs) and chemotaxis, which is then followed by a transcriptional wave of genes associated with cell cycle, also regulated by the IFN cascade. The adjunct analysis of disease stratification potential, followed by a transcriptional meta-analysis of the interferome, indicated genes such as IFI27, ISG15, and CYBRD1 as potential suitable biomarkers of disease severity. Thus, this study characterizes the landscape of the interferome signature in DENV infection, indicating that interferome dynamics are a crucial and central part of the anti-dengue immune response.

Interleukin-22 facilitates the interferon-λ-mediated production of tripartite motif protein 25 to inhibit replication of duck viral hepatitis A virus type 1

The innate immune system provides a defense against invading pathogens by inducing various interferon (IFN)-stimulated genes (ISGs). We recently reported that tripartite motif protein 25 (TRIM25), an important ISG, was highly upregulated in duck embryo hepatocyte cells (DEFs) after infection with duck viral hepatitis A virus type 1 (DHAV-1). However, the mechanism of upregulation of TRIM25 remains unknown. Here we reported that interleukin-22 (IL-22), whose expression was highly facilitated in DEFs and various organs of 1-day-old ducklings after DHAV-1 infection, highly enhanced the IFN-λ-induced production of TRIM25. The treatment with IL-22 neutralizing antibody or the overexpression of IL-22 highly suppressed or facilitated TRIM25 expression, respectively. The phosphorylation of signal transducer and activator of transcription 3 (STAT3) was crucial for the process of IL-22 enhancing IFN-λ-induced TRIM25 production, which was suppressed by WP1066, a novel inhibitor of STAT3 phosphorylation. The overexpression of TRIM25 in DEFs resulted in a high production of IFNs and reduced DHAV-1 replication, whereas the attenuated expression of IFNs and facilitated replication of DHAV-1 were observed in the RNAi group, implying that TRIM25 defended the organism against DHAV-1 propagation by inducing the production of IFNs. In summary, we reported that IL-22 activated the phosphorylation of STAT3 to enhance the IFN-λ-mediated TRIM25 expression and provide a defense against DHAV-1 by inducing IFN production.

Biological roles of A-to-I editing: implications in innate immunity, cell death, and cancer immunotherapy

Adenosine-to-inosine (A-to-I) editing, a key RNA modification widely found in eukaryotes, is catalyzed by adenosine deaminases acting on RNA (ADARs). Such RNA editing destabilizes endogenous dsRNAs, which are subsequently recognized by the sensors of innate immune and other proteins as autologous dsRNAs. This prevents the activation of innate immunity and type I interferon-mediated responses, thereby reducing the downstream cell death induced by the activation of the innate immune sensing system. ADARs-mediated editing can also occur in mRNAs and non-coding RNAs (ncRNAs) in different species. In mRNAs, A-to-I editing may lead to missense mutations and the selective splicing of coding regions. Meanwhile, in ncRNAs, A-to-I editing may affect targeting and disrupt ncRNAs maturation, leading to anomalous cell proliferation, invasion, and responses to immunotherapy. This review highlights the biological functions of A-to-I editing, its role in regulating innate immunity and cell death, and its potential molecular significance in tumorigenesis and cancer targeted therapy and immunotherapy.

Targeting Type I Interferon Induction and Signaling: How Zika Virus Escapes from Host Innate Immunity

Zika virus (ZIKV) infection causes neurological disorders and draws great attention. ZIKV infection can elicit a wide range of immune response. Type I interferons (IFNs) as well as its signaling cascade play crucial role in innate immunity against ZIKV infection and in turn ZIKV can antagonize them. ZIKV genome are mainly recognized by Toll-like receptors 3 (TLR3), TLR7/8 and RIG-I-like receptor 1 (RIG-1), which induces the expression of Type I IFNs and interferon-stimulated genes (ISGs). ISGs exert antiviral activity at different stages of the ZIKV life cycle. On the other hand, ZIKV takes multiple strategies to antagonize the Type Ⅰ IFN induction and its signaling pathway to establish a pathogenic infection, especially by using the viral nonstructural (NS) proteins. Most of the NS proteins can directly interact with the factors in the pathways to escape the innate immunity. In addition, structural proteins also participate in the innate immune evasion and activation of antibody-binding of blood dendritic cell antigen 2 (BDCA2) or inflammasome also be used to enhance ZIKV replication. In this review, we summarize the recent findings about the interaction between ZIKV infection and type I IFNs pathways and suggest potential strategies for antiviral drug development.

A stimulus-contingent positive feedback loop enables IFN-β dose-dependent activation of pro-inflammatory genes

Type I interferons (IFN) induce powerful antiviral and innate immune responses via the transcription factor, IFN-stimulated gene factor (ISGF3). However, in some pathological contexts, type I IFNs are responsible for exacerbating inflammation. Here, we show that a high dose of IFN-β also activates an inflammatory gene expression program in contrast to IFN-λ3, a type III IFN, which elicits only the common antiviral gene program. We show that the inflammatory gene program depends on a second, potentiated phase in ISGF3 activation. Iterating between mathematical modeling and experimental analysis, we show that the ISGF3 activation network may engage a positive feedback loop with its subunits IRF9 and STAT2. This network motif mediates stimulus-specific ISGF3 dynamics that are dependent on ligand, dose, and duration of exposure, and when engaged activates the inflammatory gene expression program. Our results reveal a previously underappreciated dynamical control of the JAK-STAT/IRF signaling network that may produce distinct biological responses and suggest that studies of type I IFN dysregulation, and in turn therapeutic remedies, may focus on feedback regulators within it.

Interferon-λ3 alleviates intestinal epithelium injury induced by porcine rotavirus in mice

Interferons are a group of glycoproteins that are expressed in various cell types in their inflammatory responses to infections. In this study, we explored the protective effects of porcine interferon-λ3 (PIFN-λ3) on intestinal inflammation and injury in mice induced by porcine rotavirus (PRV). BALB/c mice were administrated by PIFN-λ3 or phosphate buffer solution (PBS) for three days prior to PRV infection. We show that PRV infection caused acute inflammatory responses in mice, as indicated by increases in serum concentrations of inflammatory cytokines such as the interlukin-1β (IL-1β), interlukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) (P < 0.05). However, PIFN-λ3 administration not only decreased their concentrations but also elevated the concentrations of immunoglobulin (Ig) M and IgG in the PRV challenged mice (P < 0.05). PRV infection significantly decreased the jejunal villus height and the ratio of villus height to crypt depth (V/C); however, PIFN-λ3 treatment significantly elevated the villus height and the abundance of tight junction protein ZO-1 in the jejunum (P < 0.05). Moreover, PIFN-λ3 decreased the replication of PRV in the jejunal epithelium, but significantly increased the abundance of sIgA and the activities of maltase and sucrase in the PRV-challenged mice (P < 0.05). Interestingly, PIFN-λ3 elevated the expression levels of sodium/glucose cotransporter 1 (SGLT1) and mucin 2 (MUC2) in the PRV-challenged mice (P < 0.05). Moreover, PIFN-λ3 significantly increased the expression levels of IL-10, signal transducer and activator of transcription 1 (STAT1), and critical interferon-stimulated genes such as the 2'-5' oligoadenylate synthetase-like 1 (OASL1), interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) and radical S-adenosyl methionine domain containing 2 (RSAD2) in the jejunum upon PRV infection (P < 0.05). The anti-virus and anti-inflammatory effect of PIFN-λ3 should make it an attractive candidate to prevent various pathogen-induced bowel diseases.

Current Landscape of IFN-λ: Induction, Inhibition, and Potential Clinical Applications to Treat Respiratory Viral Infections

IFN-λ or type III IFN is an important mediator of antiviral response. Several respiratory viruses induce the production of IFN-λ during their course of infection. However, they have also developed intricate mechanisms to inhibit its expression and activity. Despite a considerable amount of research on the regulatory mechanisms of respiratory viruses on the IFN-λ response, little is still known about the effect of this cytokine on immune cells and the antiviral effects of all IFN-λ isoforms, and a better understanding of the detrimental effects of IFN-λ treatment is required. Here we highlight the relevance of IFN-λ as an antiviral cytokine in the respiratory tract. Data from studies in vitro, ex vivo, experimental animal models, and ongoing clinical trials emphasize the therapeutic opportunity that IFN-λ represents to treat and prevent different types of respiratory viral infections.

miR-130a targets CiGadd45bb to modulate the inflammatory response to bacterial infection in Ctenopharyngodon idella kidney (CIK) cells

Septicemia is a systemic inflammatory response to bacterial infection that results in a hyper-inflammatory state, which could lead to septic shock and death in grass carp (Ctenopharyngodon idella). The aim of this study was to determine the underlying mechanism of microRNA (miR-130a) in bacteria-infected grass carp. Expression levels of miR-130a against Aeromonas hydrophila (A. hydrophila) infection in Ctenopharyngodon idella kidney cells (CIK) were analyzed. Luciferase reporter assay, quantitative reverse transcription-polymerase chain reaction were performed to explore whether Ctenopharyngodon idella growth arrest and DNA damage-inducible 45 (CiGadd45bb) was a target of miR-130a. MiR-130a mimic, inhibitor and miR-control were transfected to CIK respectively. After transfection, the expression levels of proinflammatory genes were determined. Here we show that CiGadd45bb as a target of miR-130a. We also confirmed that miR-130a levels were significantly higher after being stimulated for 4 h and lower after 12 h (P < 0.01). Overexpressing miR-130a strikingly inhibited p38, JNK, ERK and TNF-a genes (P < 0.01) and silencing miR-130a activated p38, JNK, ERK, TNF-a, IFN and IL-8 (P < 0.01). Our results provide a theoretical basis for studying the molecular mechanism underlying the regulation of inflammation by miR-130a in grass carp.

Identification of a Novel Interferon Lambda Splice Variant in Chickens

Type III interferons (IFNLs) have critical roles in the host's innate immune system, also serving as the first line against pathogenic infections of mucosal surfaces. In mammals, several IFNLs have been reported; however, only limited data on the repertoire of IFNLs in avian species is available. Previous studies showed only one member in chicken (chIFNL3). Herein, we identified a novel chicken IFNL for the first time, termed chIFNL3a, which contains 354 bp, and encodes 118 amino acids. The predicted protein is 57.1% amino acid identity with chIFNL. Genetic, evolutionary, and sequence analyses indicated that the new open reading frame (ORF) groups with type III chicken IFNs represent a novel splice variant. Compared to IFNs from different species, the new ORF is clustered within the type III IFNs group. Further study showed that chIFNL3a could activate a panel of IFN-regulated genes and function mediated by the IFNL receptor, and chIFNL3a markedly inhibited the replication of Newcastle disease virus (NDV) and influenza virus in vitro. These data collectively shed light on the repertoire of IFNs in avian species and provide useful information that further elucidate the interaction of the chIFNLs and viral infection of poultry. IMPORTANCE Interferons (IFNs) are critical soluble factors in the immune system, and are composed of 3 types (I, II, and III) that utilize different receptor complexes (IFN-αR1/IFN-αR2, IFN-γR1/IFN-γR2, and IFN-λR1/IL-10R2, respectively). Herein, we identified IFNL from the genomic sequences of chicken and termed it chIFNL3a, located on chromosome 7 of chicken. Phylogenetically clustered with all known types of chicken IFNs, the finding of this IFN is considered a type III IFN. To further evaluate the biological properties of chIFNL3a, the target protein was prepared by the baculovirus expression system (BES), which could markedly inhibit the replication of NDV and influenza viruses. In this study, we uncovered a new interferon lambda splice variant of chicken, termed chIFNL3a, which could inhibit viral replication in cells. Importantly, these novel findings may extend to other viruses, offering a new direction for therapeutic interventions.

The RNA-editing enzyme ADAR1: a regulatory hub that tunes multiple dsRNA-sensing pathways

Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA-editing enzyme that catalyzes adenosine-to-inosine conversions in double-stranded RNAs (dsRNAs). In mammals, ADAR1 is composed of two isoforms: a nuclear short p110 isoform and a cytoplasmic long p150 isoform. Whereas both isoforms contain right-handed dsRNA-binding and deaminase domains, ADAR1 p150 harbors a Zα domain that binds to left-handed dsRNAs, termed Z-RNAs. Myeloma differentiation-associated gene 5 (MDA5) sensing of endogenous dsRNAs as non-self leads to the induction of type I interferon (IFN)-stimulated genes, but recent studies revealed that ADAR1 p150-mediated RNA editing, but not ADAR1 p110, prevents this MDA5-mediated sensing. ADAR1 p150-specific RNA-editing sites are present and at least a Zα domain-Z-RNA interaction is required for this specificity. Mutations in the ADAR1 gene cause Aicardi-Goutières syndrome (AGS), an infant encephalopathy with type I IFN overproduction. Insertion of a point mutation in the Zα domain of the Adar1 gene induces AGS-like encephalopathy in mice, which is rescued by concurrent deletion of MDA5. This finding indicates that impaired ADAR1 p150-mediated RNA-editing is a mechanism underlying AGS caused by an ADAR1 mutation. ADAR1 p150 also prevents ZBP1 sensing of endogenous Z-RNA, which leads to programmed cell death, via the Zα domain and its RNA-editing activity. Furthermore, ADAR1 prevents protein kinase R (PKR) sensing of endogenous right-handed dsRNAs, which leads to translational shutdown and growth arrest. Thus, ADAR1 acts as a regulatory hub that blocks sensing of endogenous dsRNAs as non-self by multiple sensor proteins, both in RNA editing-dependent and -independent manners, and is a potential therapeutic target for diseases, especially cancer.

Modulatory properties of curcumin in cancer: A narrative review on the role of interferons

The immune network is an effective network of cell types and chemical compounds established to maintain the body's homeostasis from foreign threats and to prevent the risk of a wide range of diseases; hence, its proper functioning and balance are essential. A dysfunctional immune system can contribute to various disorders, including cancer. Therefore, there has been considerable interest in molecules that can modulate the immune network. Curcumin, the active ingredient of turmeric, is one of these herbal remedies with many beneficial effects, including modulation of immunity. Curcumin is beneficial in managing various chronic inflammatory conditions, improving brain function, lowering cardiovascular disease risk, prevention and management of dementia, and prevention of aging. Several clinical studies have supported this evidence, suggesting curcumin to have an immunomodulatory and anti-inflammatory function; nevertheless, its mechanism of action is still not clear. In the current review, we aim to explore the modulatory function of curcumin through interferons in cancers.

Pathogenicity of Type I Interferons in Mycobacterium tuberculosis

Tuberculosis (TB) is a leading cause of mortality due to infectious disease and rates have increased during the emergence of COVID-19, but many of the factors determining disease severity and progression remain unclear. Type I Interferons (IFNs) have diverse effector functions that regulate innate and adaptive immunity during infection with microorganisms. There is well-documented literature on type I IFNs providing host defense against viruses; however, in this review, we explore the growing body of work that indicates high levels of type I IFNs can have detrimental effects to a host fighting TB infection. We report findings that increased type I IFNs can affect alveolar macrophage and myeloid function, promote pathological neutrophil extracellular trap responses, inhibit production of protective prostaglandin 2, and promote cytosolic cyclic GMP synthase inflammation pathways, and discuss many other relevant findings.

ADP-Ribosylation in Antiviral Innate Immune Response

Adenosine diphosphate (ADP)-ribosylation is a reversible post-translational modification catalyzed by ADP-ribosyltransferases (ARTs). ARTs transfer one or more ADP-ribose from nicotinamide adenine dinucleotide (NAD⁺) to the target substrate and release the nicotinamide (Nam). Accordingly, it comes in two forms: mono-ADP-ribosylation (MARylation) and poly-ADP-ribosylation (PARylation). ADP-ribosylation plays important roles in many biological processes, such as DNA damage repair, gene regulation, and energy metabolism. Emerging evidence demonstrates that ADP-ribosylation is implicated in host antiviral immune activity. Here, we summarize and discuss ADP-ribosylation modifications that occur on both host and viral proteins and their roles in host antiviral response.

No Association of IFNL4 Genotype With Opportunistic Infections and Cancers Among Men With Human Immunodeficiency Virus 1 Infection

BACKGROUND

IFNL4 genetic variants that are strongly associated with clearance of hepatitis C virus have been linked to risk of certain opportunistic infections (OIs) and cancers, including Kaposi sarcoma, cytomegalovirus infection, and herpes simplex virus infection. As the interferon (IFN) λ family plays a role in response to viral, bacterial, and fungal infections, IFNL4 genotype might affect risk for a wide range of OIs/cancers.

METHODS

We examined associations between genotype for the functional IFNL4 rs368234815 polymorphism and incidence of 16 OIs/cancers among 2310 men with human immunodeficiency virus (2038 white; 272 black) enrolled in the Multicenter AIDS Cohort Study during 1984-1990. Our primary analyses used Cox proportional hazards models adjusted for self-reported racial ancestry to estimate hazard ratios with 95% confidence intervals, comparing participants with the genotypes that generate IFN-λ4 and those with the genotype that abrogates IFN-λ4. We censored follow-up at the introduction of highly effective antiretroviral therapies.

RESULTS

We found no statistically significant association between IFNL4 genotype and the incidence of Kaposi sarcoma (hazard ratio, 0.92 [95% confidence interval, .76-1.11]), cytomegalovirus infection (0.94 [.71-1.24]), herpes simplex virus infection (1.37 [.68-2.93]), or any other OI/cancer. We observed consistent results using additive genetic models and after controlling for CD4 cell count through time-dependent adjustment or restriction to participants with a low CD4 cell count.

CONCLUSIONS

The absence of associations between IFNL4 genotype and these OIs/cancers provides evidence that this gene does not affect the risk of disease from opportunistic pathogens.

Transcriptome profiling highlights regulated biological processes and type III interferon antiviral responses upon Crimean-Congo hemorrhagic fever virus infection

Crimean-Congo hemorrhagic fever virus (CCHFV) is a biosafety level-4 (BSL-4) pathogen that causes Crimean-Congo hemorrhagic fever (CCHF) characterized by hemorrhagic manifestation, multiple organ failure and high mortality rate, posing great threat to public health. Despite the recently increasing research efforts on CCHFV, host cell responses associated with CCHFV infection remain to be further characterized. Here, to better understand the cellular response to CCHFV infection, we performed a transcriptomic analysis in human kidney HEK293 ​cells by high-throughput RNA sequencing (RNA-seq) technology. In total, 496 differentially expressed genes (DEGs), including 361 up-regulated and 135 down-regulated genes, were identified in CCHFV-infected cells. These regulated genes were mainly involved in host processes including defense response to virus, response to stress, regulation of viral process, immune response, metabolism, stimulus, apoptosis and protein catabolic process. Therein, a significant up-regulation of type III interferon (IFN) signaling pathway as well as endoplasmic reticulum (ER) stress response was especially remarkable. Subsequently, representative DEGs from these processes were well validated by RT-qPCR, confirming the RNA-seq results and the typical regulation of IFN responses and ER stress by CCHFV. Furthermore, we demonstrate that not only type I but also type III IFNs (even at low dosages) have substantial anti-CCHFV activities. Collectively, the data may provide new and comprehensive insights into the virus-host interactions and particularly highlights the potential role of type III IFNs in restricting CCHFV, which may help inform further mechanistic delineation of the viral infection and development of anti-CCHFV strategies.

Interferon Family Cytokines in Obesity and Insulin Sensitivity

Obesity and its associated complications are global public health concerns. Metabolic disturbances and immune dysregulation cause adipose tissue stress and dysfunction in obese individuals. Immune cell accumulation in the adipose microenvironment is the main cause of insulin resistance and metabolic dysfunction. Infiltrated immune cells, adipocytes, and stromal cells are all involved in the production of proinflammatory cytokines and chemokines in adipose tissues and affect systemic homeostasis. Interferons (IFNs) are a large family of pleiotropic cytokines that play a pivotal role in host antiviral defenses. IFNs are critical immune modulators in response to pathogens, dead cells, and several inflammation-mediated diseases. Several studies have indicated that IFNs are involved in the pathogenesis of obesity. In this review, we discuss the roles of IFN family cytokines in the development of obesity-induced inflammation and insulin resistance.

Rhinovirus Infection and Virus-Induced Asthma

While the aetiology of asthma is unclear, the onset and/or exacerbation of asthma may be associated with respiratory infections. Virus-induced asthma is also known as virus-associated/triggered asthma, and the reported main causative agent is rhinovirus (RV). Understanding the relationship between viral infections and asthma may overcome the gaps in deferential immunity between viral infections and allergies. Moreover, understanding the complicated cytokine networks involved in RV infection may be necessary. Therefore, the complexity of RV-induced asthma is not only owing to the response of airway and immune cells against viral infection, but also to allergic immune responses caused by the wide variety of cytokines produced by these cells. To better understand RV-induced asthma, it is necessary to elucidate the nature RV infections and the corresponding host defence mechanisms. In this review, we attempt to organise the complexity of RV-induced asthma to make it easily understandable for readers.

The mechanisms underlying the immune control of Zika virus infection at the maternal-fetal interface

Unlike other Flaviviruses, Zika virus (ZIKV) infection during the first trimester of pregnancy causes severe pregnancy outcomes including the devastating microcephaly and diseases associated with placental dysfunctions. We have previously reported that the maternal decidua basalis, the major maternal-fetal interface, serves as a replication platform enabling virus amplification before dissemination to the fetal compartment. However, the rate of congenital infection is quite low, suggesting the presence of a natural barrier against viral infection. Using primary cells from first-trimester pregnancy samples, we investigated in this study how the maternal decidua can interfere with ZIKV infection. Our study reveals that whether through their interactions with dNK cells, the main immune cell population of the first-trimester decidua, or their production of proinflammatory cytokines, decidual stromal cells (DSCs) are the main regulators of ZIKV infection during pregnancy. We also validate the functional role of AXL as a crucial receptor for ZIKV entry in DSCs and demonstrate that targeted inhibition of ligand-receptor interaction at the early stage of the infection is effective in drastically reducing virus pathogenesis at the maternal-fetal interface. Collectively, our results provide insights into the mechanisms through which ZIKV infection and spreading can be limited. The strategy of circumventing viral entry at the maternal-fetus interface limits virus dissemination to fetal tissues, thereby preventing congenital abnormalities.

Manganese enhances DNA- or RNA-mediated innate immune response by inducing phosphorylation of TANK-binding kinase 1

Trace metals are essential for various physiological processes, but their roles in innate immunity have not been fully explored. Here, we found that manganese (Mn) significantly enhanced DNA-mediated IFN-α, IFN-β, and IFN-λ1 production. Microarray analysis demonstrated Mn highly upregulated 351 genes, which were involved in multiple biological functions related to innate immune response. Moreover, we found that Mn2+ alone activates phosphorylation of TANK-binding kinase 1 (TBK1). Inhibiting ataxia telangiectasia mutated (ATM) kinase using ATM inhibitor or siRNA suppressed Mn-enhanced DNA-mediated immune response with decreasing phosphorylation of TBK-1, suggesting that ATM involves in Mn-dependent phosphorylation of TBK1. Given that TBK1 is an essential mediator in DNA- or RNA-mediated signaling pathways, we further demonstrated that Mn2+ suppressed infection of HSV-1 (DNA virus) or Sendai virus (RNA virus) into human macrophages by enhancing antiviral immunity. Our finding highlights a beneficial role of Mn in nucleic-acid-based preventive or therapeutic reagents against infectious diseases.

Common Microbial Genital Infections and Their Impact on the Innate Immune Response to HPV in Cervical Cells

The persistence of high-risk (HR) human papillomavirus (HPV) genotypes is a prerequisite of cervical cancer. It is not clear whether and how bacterial vaginosis (BV) and sexually transmitted infections (STIs) cause higher rates of persistent HPV infection. This study aimed to characterize mucosal innate immunity to HPV, comparing different conditions. Specifically, expression levels of genes coding for Toll-like receptors (TLR)7 and 9, several type III Interferon-related genes (IFNL1, 2, 3, their specific receptor subunit IFNLR1, and the IFN-stimulated gene ISG15). Chemokines CCL5 and CCL20 were measured in cervical cells positive, or not, for HPV, BV, and STIs. HPV DNA was detected in 51/120 (42.5%) enrolled women, two/third were HR-HPV genotypes. More than 50% of samples were BV- and/or STI-positive. HPV-positive women had BV, but not other STIs, more frequently than the HPV-negative. TLR9 and IFNL1 mRNAs were expressed in the LR, but much less in the HR HPV infection. Enhanced levels of TLR9, TLR7, IFNL2, and IFNLR1 were observed in HPV-positive women with BV and STI. TLR9-increased expression was associated with HPV persistence in previous studies; hence, bacterial coinfections may enhance this risk. Prospective measurements of type III IFNs and IFNLR1 are warranted to evaluate whether this response may act as a double-edged sword in infected epithelia.

Pseudorabies virus-induced expression and antiviral activity of type I or type III interferon depend on the type of infected epithelial cell

Type I and III Interferons (IFNs) are the initial antiviral cytokines produced in response to virus infection. These IFNs in turn bind to their respective receptors, trigger JAK-STAT signaling and induce the expression of IFN-stimulated genes (ISGs) to engage antiviral functions. Unlike the receptor for type I IFNs, which is broadly expressed, the expression of the type III IFN receptor is mainly confined to epithelial cells that line mucosal surfaces. Accumulating evidence has shown that type III IFNs may play a unique role in protecting mucosal surfaces against viral challenges. The porcine alphaherpesvirus pseudorabies virus (PRV) causes huge economic losses to the pig industry worldwide. PRV first replicates in the respiratory tract, followed by spread via neurons and via lymph and blood vessels to the central nervous system and internal organs, e.g. the kidney, lungs and intestinal tract. In this study, we investigate whether PRV triggers the expression of type I and III IFNs and whether these IFNs exert antiviral activity against PRV in different porcine epithelial cells: porcine kidney epithelial cells (PK-15), primary respiratory epithelial cells (PoREC) and intestinal porcine epithelial cells (IPEC-J2). We show that PRV triggers a multiplicity of infection-dependent type I IFN response and a prominent III IFN response in PK-15 cells, a multiplicity of infection-dependent expression of both types of IFN in IPEC-J2 cells and virtually no expression of either IFN in PoREC. Pretreatment of the different cell types with equal amounts of porcine IFN-λ3 (type III IFN) or porcine IFN-α (type I IFN) showed that IFN-α, but not IFN-λ3, suppressed PRV replication and spread in PK-15 cells, whereas the opposite was observed in IPEC-J2 cells and both types of IFN showed anti-PRV activity in PoREC cells, although the antiviral activity of IFN-α was more potent than that of IFN-λ3 in the latter cell type. In conclusion, the current data show that PRV-induced type I and III IFN responses and their antiviral activity depend to a large extent on the epithelial cell type used, and for the first time show that type III IFN displays antiviral activity against PRV in epithelial cells from the respiratory and particularly the intestinal tract.

Genome-Wide Gene Expression Analysis Reveals Unique Genes Signatures of Epithelial Reorganization in Primary Airway Epithelium Induced by Type-I, -II and -III Interferons

Biosensors such as toll-like receptors (TLR) induce the expression of interferons (IFNs) after viral infection that are critical to the first step in cell-intrinsic host defense mechanisms. Their differential influence on epithelial integrity genes, however, remains elusive. A genome-wide gene expression biosensor chip for gene expression sensing was used to examine the effects of type-I, -II, and -III IFN stimulation on the epithelial expression profiles of primary organotypic 3D air-liquid interface airway cultures. All types of IFNs induced similar interferon-stimulated genes (ISGs): OAS1, OAS2, and IFIT2. However, they differentially induced transcription factors, epithelial modulators, and pro-inflammatory genes. Type-I IFN-induced genes were associated with cell-cell adhesion and tight junctions, while type-III IFNs promoted genes important for transepithelial transport. In contrast, type-II IFN stimulated proliferation-triggering genes associated and enhanced pro-inflammatory mediator secretion. In conclusion, with our microarray system, we provide evidence that the three IFN types exceed their antiviral ISG-response by inducing distinct remodeling processes, thereby likely strengthening the epithelial airway barrier by enhancing cross-cell-integrity (I), transepithelial transport (III) and finally reconstruction through proliferation (II).

Zika Virus Replicates in the Vagina of Mice with Intact Interferon Signaling

Zika virus (ZIKV) is unusual among flaviviruses in its ability to spread between humans through sexual contact, as well as by mosquitoes. Sexual transmission has the potential to change the epidemiology and geographic range of ZIKV compared to mosquito-borne transmission and potentially could produce distinct clinical manifestations, so it is important to understand the host mechanisms that control susceptibility to sexually transmitted ZIKV. ZIKV replicates poorly in wild-type mice following subcutaneous inoculation, so most ZIKV pathogenesis studies use mice lacking type I interferon (IFN-αβ) signaling (e.g., Ifnar1^-/-). We found that wild-type mice support ZIKV replication following intravaginal infection, consistent with prior studies, although the infection remained localized to the lower female reproductive tract. Vaginal ZIKV infection required a high-progesterone state (pregnancy or pretreatment with depot medroxyprogesterone acetate [DMPA]) even in Ifnar1^-/- mice that otherwise are highly susceptible to ZIKV infection. Progesterone-mediated susceptibility did not appear to result from a compromised epithelial barrier, blunted antiviral gene induction, or changes in vaginal leukocyte populations, leaving open the mechanism by which progesterone confers susceptibility to vaginal ZIKV infection. DMPA treatment is a key component of mouse vaginal infection models for herpes simplex virus and Chlamydia, but the mechanisms by which DMPA increases susceptibility to those pathogens also remain poorly defined. Understanding how progesterone mediates susceptibility to ZIKV vaginal infection may provide insights into host mechanisms influencing susceptibility to diverse sexually transmitted pathogens. IMPORTANCE Zika virus (ZIKV) is transmitted by mosquitoes, similar to other flaviviruses. However, ZIKV is unusual among flaviviruses in its ability also to spread through sexual transmission. We found that ZIKV was able to replicate in the vaginas of wild-type mice, even though these mice do not support ZIKV replication by other routes, suggesting that the vagina is particularly susceptible to ZIKV infection. Vaginal susceptibility was dependent on a high-progesterone state, which is a common feature of mouse vaginal infection models for other pathogens, through mechanisms that have remained poorly defined. Understanding how progesterone mediates susceptibility to ZIKV vaginal infection may provide insights into host mechanisms that influence susceptibility to diverse sexually transmitted pathogens.

Cytokines and chemokines: The vital role they play in herpes simplex virus mucosal immunology

Herpes simplex viruses (HSV) types 1 and 2 are ubiquitous infections in humans. They cause orofacial and genital herpes with occasional severe complications. HSV2 also predisposes individuals to infection with HIV. There is currently no vaccine or immunotherapy for these diseases. Understanding the immunopathogenesis of HSV infections is essential to progress towards these goals. Both HSV viruses result in initial infections in two major sites - in the skin or mucosa, either after initial infection or recurrence, and in the dorsal root or trigeminal ganglia where the viruses establish latency. HSV1 can also cause recurrent infection in the eye. At all of these sites immune cells respond to control infection. T cells and resident dendritic cells (DCs) in the skin/mucosa and around reactivating neurones in the ganglia, as well as keratinocytes in the skin and mucosa, are major sources of cytokines and chemokines. Cytokines such as the Type I and II interferons synergise in their local antiviral effects. Chemokines such as CCL2, 3 and 4 are found in lesion vesicle fluid, but their exact role in determining the interactions between epidermal and dermal DCs and with resident memory and infiltrating CD4 and CD8 T cells in the skin/mucosa is unclear. Even less is known about these mechanisms in the ganglia. Here we review the data on known sources and actions of these cytokines and chemokines at cellular and tissue level and indicate their potential for preventative and therapeutic interventions.

Dung biomass smoke exposure impairs resolution of inflammatory responses to influenza infection

Epidemiological studies associate biomass smoke with an increased risk for respiratory infections in children and adults in the developing world, with 500,000 premature deaths each year attributed to biomass smoke-related acute respiratory infections including infections caused by respiratory viruses. Animal dung is a biomass fuel of particular concern because it generates more toxic compounds per amount burned than wood, and is a fuel of last resort for the poorest households. Currently, there is little biological evidence on the effects of dung biomass smoke exposure on immune responses to respiratory viral infections. Here, we investigated the impact of dung biomass exposure on respiratory infection using a mouse model of dung biomass smoke and cultured primary human small airway epithelial cells (SAECs). Mice infected with influenza A virus (IAV) after dung biomass smoke exposure had increased mortality, lung inflammation and virus mRNA levels, and suppressed expression of innate anti-viral mediators compared to air exposed mice. Importantly, there was still significant tissue inflammation 14 days after infection in dung biomass smoke-exposed mice even after inflammation had resolved in air-exposed mice. Dung biomass smoke exposure also suppressed the production of anti-viral cytokines and interferons in cultured SAECs treated with poly(I:C) or IAV. This study shows that dung biomass smoke exposure impairs the immune response to respiratory viruses and contributes to biomass smoke-related susceptibility to respiratory viral infections, likely due to a failure to resolve the inflammatory effects of biomass smoke exposure.

Antiviral Effect of pIFNLs against PEDV and VSV Infection in Different Cells

Type III and type I interferon have similar mechanisms of action, and their different receptors lead to different distributions in tissue. On mucosal surfaces, type III interferon exhibits strong antiviral activity. Porcine epidemic diarrhea virus (PEDV) is an economically important enteropathogenic coronavirus, which can cause a high incidence rate and mortality in piglets. Here, we demonstrate that porcine interferon lambda 1 (pIFNL1) and porcine interferon lambda 3 (pIFNL3) can inhibit the proliferation of vesicular stomatitis virus with an enhanced green fluorescent protein (VSV-EGFP) in different cells, and also show strong antiviral activity when PEDV infects Vero cells. Both forms of pIFNLs were shown to be better than porcine interferon alpha (pIFNα), the antiviral activity of pIFNL1 is lower than that of pIFNL3. Therefore, our results provide experimental evidence for the inhibition of PEDV infection by pIFNLs, which may provide a promising treatment for the prevention and treatment of Porcine epidemic diarrhea (PED) in piglets.

The gamble between oncolytic virus therapy and IFN

Various studies are being conducted on oncolytic virotherapy which one of the mechanisms is mediating interferon (IFN) production by it exerts antitumor effects. The antiviral effect of IFN itself has a negative impact on the inhibition of oncolytic virus or tumor eradication. Therefore, it is very critical to understand the mechanism of IFN regulation by oncolytic viruses, and to define its mechanism is of great significance for improving the antitumor effect of oncolytic viruses. This review focuses on the regulatory mechanisms of IFNs by various oncolytic viruses and their combination therapies. In addition, the exerting and the producing pathways of IFNs are briefly summarized, and some current issues are put forward.

Unbiased discovery of autoantibodies associated with severe COVID-19 via genome-scale self-assembled DNA-barcoded protein libraries

Pathogenic autoreactive antibodies that may be associated with life-threatening coronavirus disease 2019 (COVID-19) remain to be identified. Here, we show that self-assembled genome-scale libraries of full-length proteins covalently coupled to unique DNA barcodes for analysis by sequencing can be used for the unbiased identification of autoreactive antibodies in plasma samples. By screening 11,076 DNA-barcoded proteins expressed from a sequence-verified human ORFeome library, the method, which we named MIPSA (for Molecular Indexing of Proteins by Self-Assembly), allowed us to detect circulating neutralizing type-I and type-III interferon (IFN) autoantibodies in five plasma samples from 55 patients with life-threatening COVID-19. In addition to identifying neutralizing type-I IFN-α and IFN-ω autoantibodies and other previously known autoreactive antibodies in patient plasma, MIPSA enabled the detection of as yet unidentified neutralizing type-III anti-IFN-λ3 autoantibodies that were not seen in healthy plasma samples or in convalescent plasma from ten non-hospitalized individuals with COVID-19. The low cost and simple workflow of MIPSA will facilitate unbiased high-throughput analyses of protein-antibody, protein-protein and protein-small-molecule interactions.

Antiviral Activity of Porcine IFN-λ3 and IFN-α against Porcine Rotavirus In Vitro

Interferons (IFNs) play a major role in the host’s antiviral innate immunity. In response to viral infection, IFNs bind their receptors and initiate a signaling cascade, leading to the accurate transcriptional regulation of hundreds of IFN-stimulated genes (ISGs). Porcine rotavirus (PoRV) belongs to genus Rotavirus of the Reoviridae family; the infection is a global epidemic disease and a major threat to the pig industry. In this study, we found that IFN-λ3 inhibited the replication of PoRV in both MA104 cells and IPEC-J2 cells, and this inhibition was dose-dependent. Furthermore, the antiviral activity of IFN-λ3 was more potent in IPEC-J2 cells than in MA104 cells. Further research showed that IFN-λ3 and IFN-α might inhibit PoRV infection by activating ISGs, i.e., MxA, OASL and ISG15, in IPEC-J2 cells. However, the co-treatment of IFN-λ3 and IFN-α did not enhance the antiviral activity. Our data demonstrated that IFN-λ3 had antiviral activity against PoRV and may serve as a useful antiviral candidate against PoRV, as well as other viruses in swine.