IFN-lambda1 (IL-29) inhibits GATA3 expression and suppresses Th2 responses in human naive and memory T cells. Blood. 2009;113:5829-5838. [PMID: 19346497 DOI: 10.1182/blood-2008-09-179507]

Effect of sitagliptin therapy on IL-29 and its associated signaling molecules in patients with type 2 diabetes mellitus

OBJECTIVE

The potential immunoregulatory capacity of sitagliptin on interleukin-29 (IL-29) and genes involved in its intracellular pathway were explored in type 2 diabetes mellitus (T2D).

MATERIALS AND METHODS

T2D patients treated with six months of sitagliptin (Sita+), patients not treated with sitagliptin (Sita-), and healthy controls (HCs) were included. IL-29 levels in the supernatant of stimulated mononuclear immune cells was determined with ELISA. The mRNA expression levels of IL-29, FOS, JUN, NF-AT2, NF-KB1, STAT1-2, IRF1, IRF3, IRF7, and IRF9 was assessed with real-time qPCR.

RESULTS

Increased protein and gene levels of IL-29 were observed in Sita- group compared to HCs (p < 0.001 and p = 0.026), while those levels were diminished in Sita+ group in comparison with Sita- group (p < 0.001 and p = 0.008). Expression of FOS, NF-AT2 and NF-KB1 in Sita- patients was higher than HCs (p = 0.018, p = 0.021, and p = 0.001). A significant decrease in expression of FOS, NF-AT2, and NF-KB1 was found in Sita+ group versus Sita- parients (p = 0.027, p = 0.003, and p = 0.002). In Sita- patients, IL-29 levels were correlated to glucose metabolism parameters including FPG and HbA1c (p < 0.05 for all).

CONCLUSION

Sitagliptin administration has a regulatory effect on the aggressive expression of IL-29 and its signaling molecules including FOS, NF-AT2 and NF-KB1 in T2D.

Interferon lambda in respiratory viral infection: immunomodulatory functions and antiviral effects in epithelium

Type III interferon (IFN-λ), a new member of the IFN family, was initially considered to possess antiviral functions similar to those of type I interferon, both of which are induced via the JAK/STAT pathway. Nevertheless, recent findings demonstrated that IFN-λ exerts a nonredundant antiviral function at the mucosal surface, preferentially produced in epithelial cells in contrast to type I interferon, and its function cannot be replaced by type I interferon. This review summarizes recent studies showing that IFN-λ inhibits the spread of viruses from the cell surface to the body. Further studies have found that the role of IFN-λ is not only limited to the abovementioned functions, but it can also can exert direct and/or indirect effects on immune cells in virus-induced inflammation. This review focuses on the antiviral activity of IFN-λ in the mucosal epithelial cells and its action on immune cells and summarizes the pathways by which IFN-λ exerts its action and differentiates it from other interferons in terms of mechanism. Finally, we conclude that IFN-λ is a potent epidermal antiviral factor that enhances the respiratory mucosal immune response and has excellent therapeutic potential in combating respiratory viral infections.

An Engineered Probiotic Produces a Type III Interferon IFNL1 and Reduces Inflammations in in vitro Inflammatory Bowel Disease Models

The etiology of inflammatory bowel diseases (IBDs) frequently results in the uncontrolled inflammation of intestinal epithelial linings and the local environment. Here, we hypothesized that interferon-driven immunomodulation could promote anti-inflammatory effects. To test this hypothesis, we engineered probiotic Escherichia coli Nissle 1917 (EcN) to produce and secrete a type III interferon, interferon lambda 1 (IFNL1), in response to nitric oxide (NO), a well-known colorectal inflammation marker. We then validated the anti-inflammatory effects of the engineered EcN strains in two in vitro models: a Caco-2/Jurkat T cell coculture model and a scaffold-based 3D coculture IBD model that comprises intestinal epithelial cells, myofibroblasts, and T cells. The IFNL1-expressing EcN strains upregulated Foxp3 expression in T cells and thereafter reduced the production of pro-inflammatory cytokines such as IL-13 and -33, significantly ameliorating inflammation. The engineered strains also rescued the integrity of the inflamed epithelial cell monolayer, protecting epithelial barrier integrity even under inflammation. In the 3D coculture model, IFNL1-expressing EcN treatment enhanced the population of regulatory T cells and increased anti-inflammatory cytokine IL-10. Taken together, our study showed the anti-inflammatory effects of IFNL1-expressing probiotics in two in vitro IBD models, demonstrating their potential as live biotherapeutics for IBD immunotherapy.

Macrophages and neutrophils express IFNλs in granulomas from Mycobacterium tuberculosis-infected nonhuman primates

Granulomas are the hallmark of Mycobacterium tuberculosis (Mtb) infection. Cytokine-mediated signaling can modulate immune function; thus, understanding the cytokine milieu in granulomas is critical for understanding immunity in tuberculosis (TB). Interferons (IFNs) are important immune mediators in TB, and while type 1 and 2 IFNs have been extensively studied, less is known about type 3 IFNs (IFNλs) in TB. To determine if IFNλs are expressed in granulomas, which cells express them, and how granuloma microenvironments influence IFNλ expression, we investigated IFNλ1 and IFNλ4 expression in macaque lung granulomas. We identified IFNλ expression in granulomas, and IFNλ levels negatively correlated with bacteria load. Macrophages and neutrophils expressed IFNλ1 and IFNλ4, with neutrophils expressing higher levels of each protein. IFNλ expression varied in different granuloma microenvironments, with lymphocyte cuff macrophages expressing more IFNλ1 than epithelioid macrophages. IFNλ1 and IFNλ4 differed in their subcellular localization, with IFNλ4 predominantly localizing inside macrophage nuclei. IFNλR1 was also expressed in granulomas, with intranuclear localization in some cells. Further investigation demonstrated that IFNλ signaling is driven in part by TLR2 ligation and was accompanied by nuclear translocation of IFNλR1. Our data indicate that IFNλs are part of the granuloma cytokine milieu that may influence myeloid cell function and immunity in TB.

ITGB4 Deficiency in Airway Epithelium Aggravates RSV Infection and Increases HDM Sensitivity

Background

The heterogeneity of RSV-infected pathology phenotype in early life is strongly associate with increased susceptibility of asthma in later life. However, the inner mechanism of this heterogeneity is still obscure. ITGB4 is a down-regulated adhesion molecular in the airway epithelia of asthma patients which may participate in the regulation of RSV infection related intracellular pathways.

Object

This study was designed to observe the involvement of ITGB4 in the process of RSV infection and the effect of ITGB4 deficiency on anti-RSV responses of airway epithelia.

Results

RSV infection caused a transient decrease of ITGB4 expression both in vitro and in vivo. Besides, ITGB4 deficiency induced not only exacerbated RSV infection, but also enhanced HDM sensitivity in later life. Moreover, IFN III (IFN-λ) was significantly suppressed during RSV infection in ITGB4 deficient airway epithelial cells. Furthermore, the suppression of IFN-λ were regulated by IRF-1 through the phosphorylation of EGFR in airway epithelial cells after RSV infection.

Conclusion

These results demonstrated the involvement of ITGB4 deficiency in the development of enhance RSV infection in early life and the increased HDM sensitivity in later life by down-regulation of IFN-λ through EGFR/IRF-1 pathway in airway epithelial cells.

Targeting IFN-λ Signaling Promotes Recovery from Central Nervous System Autoimmunity

Type III IFNs (IFNLs) are newly discovered cytokines, acting at epithelial and other barriers, that exert immunomodulatory functions in addition to their primary roles in antiviral defense. In this study, we define a role for IFNLs in maintaining autoreactive T cell effector function and limiting recovery in a murine model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis. Genetic or Ab-based neutralization of the IFNL receptor (IFNLR) resulted in lack of disease maintenance during experimental autoimmune encephalomyelitis, with loss of CNS Th1 effector responses and limited axonal injury. Phenotypic effects of IFNLR signaling were traced to increased APC function, with associated increase in T cell production of IFN-γ and GM-CSF. Consistent with this, IFNL levels within lesions of CNS tissues derived from patients with MS were elevated compared with MS normal-appearing white matter. Furthermore, expression of IFNLR was selectively elevated in MS active lesions compared with inactive lesions or normal-appearing white matter. These findings suggest IFNL signaling as a potential therapeutic target to prevent chronic autoimmune neuroinflammation.

Regulation and Function of Interferon-Lambda (IFNλ) and Its Receptor in Asthma

Asthma is a chronic respiratory disease affecting people of all ages, especially children, worldwide. Origins of asthma are suggested to be placed in early life with heterogeneous clinical presentation, severity and pathophysiology. Exacerbations of asthma disease can be triggered by many factors, including viral respiratory tract infections. Rhinovirus (RV) induced respiratory infections are the predominant cause of the common cold and also play a crucial role in asthma development and exacerbations. Rhinovirus mainly replicates in epithelial cells lining the upper and lower respiratory tract. Type III interferons, also known as interferon-lambda (IFNλ), are potent immune mediators of resolution of infectious diseases but they are known to be involved in autoimmune diseases as well. The protective role of type III IFNs in antiviral, antibacterial, antifungal and antiprotozoal functions is of major importance for our innate immune system. The IFNλ receptor (IFNλR) is expressed in selected types of cells like epithelial cells, thus orchestrating a specific immune response at the site of viruses and bacteria entry into the body. In asthma, IFNλ restricts the development of TH2 cells, which are induced in the airways of asthmatic patients. Several studies described type III IFNs as the predominant type of interferon increased after infection caused by respiratory viruses. It efficiently reduces viral replication, viral spread into the lungs and viral transmission from infected to naive individuals. Several reports showed that bronchial epithelial cells from asthmatic subjects have a deficient response of type III interferon after RV infection ex vivo. Toll like Receptors (TLRs) recognize pathogen-associated molecular patterns (PAMPs) expressed on infectious agents, and induce the development of antiviral and antibacterial immunity. We recently discovered that activation of TLR7/8 resulted in enhanced IFNλ receptor mRNA expression in PBMCs of healthy and asthmatic children, opening new therapeutic frontiers for rhinovirus-induced asthma. This article reviews the recent advances of the literature on the regulated expression of type III Interferons and their receptor in association with rhinovirus infection in asthmatic subjects.

Antiviral Responses in Cancer: Boosting Antitumor Immunity Through Activation of Interferon Pathway in the Tumor Microenvironment

In recent years, it became apparent that cancers either associated with viral infections or aberrantly expressing endogenous retroviral elements (EREs) are more immunogenic, exhibiting an intense intra-tumor immune cell infiltration characterized by a robust cytolytic apparatus. On the other hand, epigenetic regulation of EREs is crucial to maintain steady-state conditions and cell homeostasis. In line with this, epigenetic disruptions within steady-state cells can lead to cancer development and trigger the release of EREs into the cytoplasmic compartment. As such, detection of viral molecules by intracellular innate immune sensors leads to the production of type I and type III interferons that act to induce an antiviral state, thus restraining viral replication. This knowledge has recently gained momentum due to the possibility of triggering intratumoral activation of interferon responses, which could be used as an adjuvant to elicit strong anti-tumor immune responses that ultimately lead to a cascade of cytokine production. Accordingly, several therapeutic approaches are currently being tested using this rationale to improve responses to cancer immunotherapies. In this review, we discuss the immune mechanisms operating in viral infections, show evidence that exogenous viruses and endogenous retroviruses in cancer may enhance tumor immunogenicity, dissect the epigenetic control of EREs, and point to interferon pathway activation in the tumor milieu as a promising molecular predictive marker and immunotherapy target. Finally, we briefly discuss current strategies to modulate these responses within tumor tissues, including the clinical use of innate immune receptor agonists and DNA demethylating agents.

Type III Interferons: Emerging Roles in Autoimmunity

Type III interferons (IFNs) or the lambda IFNs (IFNLs or IFN-λs) are antimicrobial cytokines that play key roles in immune host defense at endothelial and epithelial barriers. IFNLs signal via their heterodimeric receptor, comprised of two subunits, IFNLR1 and interleukin (IL)10Rβ, which defines the cellular specificity of the responses to the cytokines. Recent studies show that IFNL signaling regulates CD4+ T cell differentiation, favoring Th1 cells, which has led to the identification of IFNL as a putative therapeutic target for autoimmune diseases. Here, we summarize the IFNL signaling pathways during antimicrobial immunity, IFNL-mediated immunomodulation of both innate and adaptive immune cells, and induction of autoimmunity.

Monocytes differentiated into macrophages and dendritic cells in the presence of human IFN-λ3 or IFN-λ4 show distinct phenotypes

Human IFN-λ4 is expressed by only a subset of individuals who possess the ΔG variant allele at the dinucleotide polymorphism rs368234815. Recent genetic studies have shown an association between rs368234815 and different infectious and inflammatory disorders. It is not known if IFN-λ4 has immunomodulatory activity. The expression of another type III IFN, IFN-λ3, is also controlled by genetic polymorphisms that are strongly linked to rs368234815. Therefore, it is of interest to compare these two IFNs for their effects on immune cells. Herein, using THP-1 cells, it was confirmed that IFN-λ4 could affect the differentiation status of macrophage-like cells and dendritic cells (DCs). The global gene expression changes induced by IFN-λ4 were also characterized in in vitro generated primary macrophages. Next, human PBMC-derived CD14+ monocytes were used to obtain M1 and M2 macrophages and DCs in the presence of IFN-λ3 or IFN-λ4. These DCs were cocultured with CD4+ Th cells derived from allogenic donors and their in vitro cytokine responses were measured. The specific activity of recombinant IFN-λ4 was much lower than that of IFN-λ3, as shown by induction of IFN-stimulated genes. M1 macrophages differentiated in the presence of IFN-λ4 showed higher IL-10 secretion than those differentiated in IFN-λ3. Coculture experiments suggested that IFN-λ4 could confer a Th2-biased phenotype to allogenic Th cells, wherein IFN-λ3, under similar circumstances, did not induce a significant bias toward either a Th1 or Th2 phenotype. This study shows for the first time that IFN-λ4 may influence immune responses by immunomodulation.

Double-edged effects of interferons on the regulation of cancer-immunity cycle

Interferons (IFNs) are a large family of pleiotropic cytokines that regulate both innate and adaptive immunity and show anti-cancer effects in various cancer types. Moreover, it was revealed that IFN signaling plays critical roles in the success of cancer therapy strategies, thereby enhancing their therapeutic effects. However, IFNs have minimal or even adverse effects on cancer eradication, and mediate cancer immune escape in some instances. Thus, IFNs have a double-edged effect on the cancer immune response. Recent studies suggest that IFNs regulate each step of the cancer immunity-cycle, consisting of cancer antigen release, presentation of antigens and activation of T cells, trafficking and infiltration of effector T cells into the tumor microenvironment, and recognition and killing of cancer cells, which contributes to our understanding of the mechanisms of IFNs in regulating cancer immunity. In this review, we focus on IFNs and cancer immunity and elaborate on the roles of IFNs in regulating the cancer-immunity cycle.

Entecavir-induced interferon-λ1 suppresses type 2 innate lymphoid cells in patients with hepatitis B virus-related liver cirrhosis

The immunomodulatory effects of entecavir (ETV) in anti-hepatitis B virus (HBV) therapy have long been recognized. This study aimed to determine the effects of ETV on non-natural killer innate lymphoid cells (non-NK ILCs) in HBV-related liver disease progression. We enrolled treatment-naïve chronic hepatitis B (CHB) and HBV-related liver cirrhosis (LC) patients treated with ETV for 24 months. Before and after therapy, the frequency and cytokine profiles of ILC2s and non-NK ILCs subset homeostasis and their clinical significance were determined, and serial serum interferon (IFN)-λ levels were analysed. Peripheral blood mononuclear cells (PBMCs) of untreated LC patients were cultured with serum from untreated and ETV-treated LC patients in addition to being subject to IFN-λ1 neutralization and stimulation, and the frequency and cytokine production of ILC2s as well as non-NK ILCs subset ratios were calculated. Furthermore, IFN-λ receptor expression on non-NK ILCs and dendritic cells (DCs) was measured. After 24 months of ETV treatment, the frequency and cytokine production of ILC2s (IL-4, IL-13, IFN-γ, TNF-α) decreased with increased ILC1/ILC2 and decreased ILC2/ILC3 ratios, revealing a close association with disease status in LC patients. Long-term ETV administration-induced serum IFN-λ1 levels were negatively correlated with ILC2s. ETV-treated LC serum culture and IFN-λ1 stimulation yielded similar effects on suppression of ILC2s, and IFN-λ1 neutralization in serum culture partly inhibited this effect. The IFN-λ receptor was detected on DCs but not on non-NK ILCs. In conclusion, ETV suppresses the frequency and cytokine profiles of ILC2s by increasing IFN-λ1 in LC patients.

B cell intrinsic expression of IFNλ receptor suppresses the acute humoral immune response to experimental blood-stage malaria

Antibodies play a critical protective role in the host response to blood-stage malaria infection. The role of cytokines in shaping the antibody response to blood-stage malaria is unclear. Interferon lambda (IFNλ), a type III interferon, is a cytokine produced early during blood-stage malaria infection that has an unknown physiological role during malaria infection. We demonstrate that B cell-intrinsic IFNλ signals suppress the acute antibody response, acute plasmablast response, and impede acute parasite clearance during a primary blood-stage malaria infection. Our findings demonstrate a previously unappreciated role for B cell intrinsic IFNλ-signaling in the initiation of the humoral immune response in the host response to experimental malaria.

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

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

Protective Potentials of Type III Interferons in COVID-19 Patients: Lessons from Differential Properties of Type I- and III Interferons

While an appropriately regulated production of interferons (IFNs) performs a fundamental role in the defense against coronaviruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), dysregulated overproduction of inflammatory mediators can play an important role in the development of SARS-CoV-2 infection-related complications, such as acute respiratory distress syndrome. As the principal constituents of innate immunity, both type I and III IFNs share antiviral features. However, important properties, including preferential expression at mucosal barriers (such as respiratory tract), local influences, lower receptor distribution, smaller target cell types, noninflammatory effects, and immunomodulatory impacts, were attributed only to type III IFNs. Accordingly, type III IFNs can establish an optimal effective antiviral response, without triggering exaggerated systemic inflammation that is generally attributed to the type I IFNs. However, some harmful effects were attributed to the III IFNs and there are also major differences between human and mouse concerning the immunomodulatory effects of III IFNs. Here, we describe the differential properties of type I and type III IFNs and present a model of IFN response during SARS-COV-2 infection, while highlighting the superior potential of type III IFNs in COVID-19.

Differential expression of interferon-lambda receptor 1 splice variants determines the magnitude of the antiviral response induced by interferon-lambda 3 in human immune cells

Type III interferons (IFN-lambdas(λ)) are important cytokines that inhibit viruses and modulate immune responses by acting through a unique IFN-λR1/IL-10RB heterodimeric receptor. Until now, the primary antiviral function of IFN-λs has been proposed to be at anatomical barrier sites. Here, we examine the regulation of IFN-λR1 expression and measure the downstream effects of IFN-λ3 stimulation in primary human blood immune cells, compared with lung or liver epithelial cells. IFN-λ3 directly bound and upregulated IFN-stimulated gene (ISG) expression in freshly purified human B cells and CD8+ T cells, but not monocytes, neutrophils, natural killer cells, and CD4+ T cells. Despite similar IFNLR1 transcript levels in B cells and lung epithelial cells, lung epithelial cells bound more IFN-λ3, which resulted in a 50-fold greater ISG induction when compared to B cells. The reduced response of B cells could be explained by higher expression of the soluble variant of IFN-λR1 (sIFN-λR1), which significantly reduced ISG induction when added with IFN-λ3 to peripheral blood mononuclear cells or liver epithelial cells. T-cell receptor stimulation potently, and specifically, upregulated membrane-bound IFNLR1 expression in CD4+ T cells, leading to greater antiviral gene induction, and inhibition of human immunodeficiency virus type 1 infection. Collectively, our data demonstrate IFN-λ3 directly interacts with the human adaptive immune system, unlike what has been previously shown in published mouse models, and that type III IFNs could be potentially utilized to suppress both mucosal and blood-borne viral infections.

IL-29 promoted obesity-induced inflammation and insulin resistance

Adipocyte-macrophage crosstalk plays a critical role to regulate adipose tissue microenvironment and cause chronic inflammation in the pathogenesis of obesity. Interleukin-29 (IL-29), a member of type 3 interferon family, plays a role in host defenses against microbes, however, little is known about its role in metabolic disorders. We explored the function of IL-29 in the pathogenesis of obesity-induced inflammation and insulin resistance. We found that serum IL-29 level was significantly higher in obese patients. IL-29 upregulated IL-1β, IL-8, and monocyte chemoattractant protein-1 (MCP-1) expression and decreased glucose uptake and insulin sensitivity in human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes through reducing glucose transporter 4 (GLUT4) and AKT signals. In addition, IL-29 promoted monocyte/macrophage migration. Inhibition of IL-29 could reduce inflammatory cytokine production in macrophage-adipocyte coculture system, which mimic an obese microenvironment. In vivo, IL-29 reduced insulin sensitivity and increased the number of peritoneal macrophages in high-fat diet (HFD)-induced obese mice. IL-29 increased M1/M2 macrophage ratio and enhanced MCP-1 expression in adipose tissues of HFD mice. Therefore, we have identified a critical role of IL-29 in obesity-induced inflammation and insulin resistance, and we conclude that IL-29 may be a novel candidate target for treating obesity and insulin resistance in patients with metabolic disorders.

Insights into IL-29: Emerging role in inflammatory autoimmune diseases

Interleukin-29 (IL-29) is a newly discovered member of type III interferon. It mediates signal transduction via binding to its receptor complex and activates downstream signalling pathways, and therefore induces the generation of inflammatory components. Recent studies reported that expression of IL-29 is dysregulated in inflammatory autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, Sjögren's syndrome, psoriasis and systemic sclerosis. Furthermore, functional analysis revealed that IL-29 may involve in the pathogenesis of the inflammatory autoimmune disorders. In this review, we will systematically review the current knowledge about IL-29. The information collected revealed the regulatory role of IL-29 and may give important implications for its potential in clinical treatment.

Diminished secretion and function of IL-29 is associated with impaired IFN-α response of neonatal plasmacytoid dendritic cells

Plasmacytoid dendritic cells (pDCs) are key players in the antiviral immune response and type III IFNs such as IL-29 appear to play a pivotal role in pDC function. Pronounced susceptibility to viral infections in neonates is partly resulting from diminished antiviral immune mechanisms. Accordingly, the aim of the present study was to investigate the impact of IL-29 in the altered immune response of neonatal pDCs. PBMCs of adult and term newborns were stimulated with CpG-ODN2216 in the presence or absence of IL-29 and assessed for IFN-α production, downstream-signaling, and activation marker expression. A significantly lower IL-29 production after TLR9-specific stimulation was demonstrated in neonatal pDCs. IL-29 enhanced the IFN-α production of pDCs in adults compared to newborns. Newborn pDCs displayed a significantly lower surface expression of IL-10 and IL-28Rα receptor resulting in diminished STAT1 and IRF7 activation. Interestingly, concomitant stimulation with CpG-ODN2216/IL-29 had no impact on the expression of surface activation and maturation markers of pDCs in neither population. The diminished antiviral immune response of neonatal pDCs is associated with reduced production and cellular responses toward IL-29. Potential therapeutic agents enhancing the IL-29 response in neonatal pDCs possibly augment viral protection in newborns.

Signaling Pathways of Type I and Type III Interferons and Targeted Therapies in Systemic Lupus Erythematosus

Type I and type III interferons (IFNs) share several properties in common, including the induction of signaling pathways, the activation of gene transcripts, and immune responses, against viral infection. Recent advances in the understanding of the molecular basis of innate and adaptive immunity have led to the re-examination of the role of these IFNs in autoimmune diseases. To date, a variety of IFN-regulated genes, termed IFN signature genes, have been identified. The expressions of these genes significantly increase in systemic lupus erythematosus (SLE), highlighting the role of type I and type III IFNs in the pathogenesis of SLE. In this review, we first discussed the signaling pathways and the immunoregulatory roles of type I and type III IFNs. Next, we discussed the roles of these IFNs in the pathogenesis of autoimmune diseases, including SLE. In SLE, IFN-stimulated genes induced by IFN signaling contribute to a positive feedback loop of autoimmunity, resulting in perpetual autoimmune inflammation. Based on this, we discussed the use of several specific IFN blocking strategies using anti-IFN-α antibodies, anti-IFN-α receptor antibodies, and IFN-α-kinoid or downstream small molecules, which intervene in Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathways, in clinical trials for SLE patients. Hopefully, the development of novel regimens targeting IFN signaling pathways will shed light on promising future therapeutic applications for SLE patients.

Shared and Distinct Functions of Type I and Type III Interferons

Type I interferons (IFNs) (IFN-α, IFN-β) and type III IFNs (IFN-λ) share many properties, including induction by viral infection, activation of shared signaling pathways, and transcriptional programs. However, recent discoveries have revealed context-specific functional differences. Here, we provide a comprehensive review of type I and type III IFN activities, highlighting shared and distinct features from molecular mechanisms through physiological responses. Beyond discussing canonical antiviral functions, we consider the adaptive immune priming, anti-tumor, and autoimmune functions of IFNs. We discuss a model wherein type III IFNs serve as a front-line defense that controls infection at epithelial barriers while minimizing damaging inflammatory responses, reserving the more potent type I IFN response for when local responses are insufficient. In this context, we discuss current therapeutic applications targeting these cytokine pathways and highlight gaps in understanding of the biology of type I and type III IFNs in health and disease.

The double stranded RNA analog poly-IC elicits both robust IFN-λ production and oncolytic activity in human gastrointestinal cancer cells

Purpose

Type III IFN (IFN-λ) is the dominant frontline response over type I IFN in human normal intestinal epithelial cells upon viral infection, this response being mimicked by the dsRNA analog poly-IC. Poly-IC also induces cell death in murine intestinal crypts ex vivo. Here we examined whether these innate defense functions of normal intestinal epithelial cells are recapitulated in gastrointestinal carcinoma cells so that they could be harnessed to exert both immunoadjuvant and oncolytic functions, an unknown issue yet.

Experimental design

Four human gastrointestinal carcinoma cell lines versus the Jurkat lymphoma cell line were used to assess the effects of intracellular poly-IC on i) IFN-λ secretion and cell proliferation and ii) role of NFκB signaling using the NFκB inhibitory peptide SN50 as a screening probe and a siRNA approach.

Results

Poly-IC induced in all cell lines except Jurkat both a robust IFN-λ secretion and a cytoreductive effect on adherent cells, restricted to proliferating cells and associated with cellular shedding and reduced clonogenicity of the shed cells. Collectively these findings demonstrate the oncolytic activity of poly-IC. Inhibiting NFκB in T84 cells using a siRNA approach decreased IFN-λ production without protecting the cells from the poly-IC oncolytic effects. In line with these findings IFN-λ, that upregulated the anti-viral protein MxA, was unable per se to alter T84 cell proliferation.

Conclusion

Our demonstration that poly-IC-induced concomitant recapitulation of two innate functions of normal intestine, i.e. IFN-λ production and cell death, by human gastrointestinal cancer cells opens new perspectives in gastrointestinal cancer treatment.

Mutation of IFNLR1, an interferon lambda receptor 1, is associated with autosomal-dominant non-syndromic hearing loss

Background Hereditary sensorineural hearing loss is a genetically heterogeneous disorder. Objectives This study was designed to explore the genetic etiology of deafness in a large Chinese family with autosomal dominant, nonsyndromic, progressive sensorineural hearing loss (ADNSHL). Methods Whole exome sequencing and linkage analysis were performed to identify pathogenic mutation. Inner ear expression of Ifnlr1 was investigated by immunostaining in mice. ifnlr1 Morpholino knockdown Zebrafish were constructed to explore the deafness mechanism. Results We identified a cosegregating heterozygous missense mutation, c.296G>A (p.Arg99His) in the gene encoding interferon lambda receptor 1 (IFNLR1) - a protein that functions in the Jak/ STAT pathway- are associated with ADNSHL Morpholino knockdown of ifnlr1 leads to a significant decrease in hair cells and non-inflation of the swim bladder in late-stage zebrafish, which can be reversed by injection with normal Zebrafish ifnlr1 mRNA. Knockdown of ifnlr1 in zebrafish causes significant upregulation of cytokine receptor family member b4 (interleukin-10r2), jak1, tyrosine kinase 2, stat3, and stat5b in the Jak1/STAT3 pathway at the mRNA level. ConclusionIFNLR1 function is required in the auditory system and that IFNLR1 mutations are associated with ADNSHL. To the best of our knowledge, this is the first study implicating an interferon lambda receptor in auditory function.

Interferon-λs: Front-Line Guardians of Immunity and Homeostasis in the Respiratory Tract

Type III interferons (IFNs), also termed lambda IFNs (IFNλs) or interleukins-28/29, constitute a new addition to the IFN family. They are induced upon infection and are particularly abundant at barrier surfaces, such as the respiratory and gastrointestinal tracts. Although they signal through a unique heterodimeric receptor complex comprising IFNLR1 and IL10RB, they activate a downstream signaling pathway remarkably similar to that of type I IFNs and share many functions with them. Yet, they also have important differences which are only now starting to unfold. Here, we review the current literature implicating type III IFNs in the regulation of immunity and homeostasis in the respiratory tract. We survey the common and unique characteristics of type III IFNs in terms of expression patterns, cellular targets, and biological activities and discuss their emerging role in first line defenses against respiratory viral infections. We further explore their immune modulatory functions and their involvement in the regulation of inflammatory responses during chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease. Type III IFNs are, therefore, arising as front-line guardians of immune defenses in the respiratory tract, fine tuning inflammation, and as potential novel therapeutics for the treatment of diverse respiratory diseases, including influenza virus infection and asthma.

Interferon-λ Mediates Non-redundant Front-Line Antiviral Protection against Influenza Virus Infection without Compromising Host Fitness

Lambda interferons (IFNλs) or type III IFNs share homology, expression patterns, signaling cascades, and antiviral functions with type I IFNs. This has complicated the unwinding of their unique non-redundant roles. Through the systematic study of influenza virus infection in mice, we herein show that IFNλs are the first IFNs produced that act at the epithelial barrier to suppress initial viral spread without activating inflammation. If infection progresses, type I IFNs come into play to enhance viral resistance and induce pro-inflammatory responses essential for confronting infection but causing immunopathology. Central to this are neutrophils which respond to both cytokines to upregulate antimicrobial functions but exhibit pro-inflammatory activation only to type I IFNs. Accordingly, Ifnlr1^-/- mice display enhanced type I IFN production, neutrophilia, lung injury, and lethality, while therapeutic administration of PEG-IFNλ potently suppresses these effects. IFNλs therefore constitute the front line of antiviral defense in the lung without compromising host fitness.

A functional IFN-λ4-generating DNA polymorphism could protect older asthmatic women from aeroallergen sensitization and associate with clinical features of asthma

Lambda interferons (IFNLs) have immunomodulatory functions at epithelial barrier surfaces. IFN-λ4, a recent member of this family is expressed only in a subset of the population due to a frameshift-causing DNA polymorphism rs368234815. We examined the association of this polymorphism with atopy (aeroallergen sensitization) and asthma in a Polish hospital-based case-control cohort comprising of well-characterized adult asthmatics (n = 326) and healthy controls (n = 111). In the combined cohort, we saw no association of the polymorphism with asthma and/or atopy. However, the IFN-λ4-generating ΔG allele protected older asthmatic women (>50 yr of age) from atopic sensitization. Further, ΔG allele significantly associated with features of less-severe asthma including bronchodilator response and corticosteroid usage in older women in this Polish cohort. We tested the association of related IFNL locus polymorphisms (rs12979860 and rs8099917) with atopy, allergic rhinitis and presence/absence of asthma in three population-based cohorts from Europe, but saw no significant association of the polymorphisms with any of the phenotypes in older women. The polymorphisms associated marginally with lower occurrence of asthma in men/older men after meta-analysis of data from all cohorts. Functional and well-designed replication studies may reveal the true positive nature of these results.

IFN-λ suppresses intestinal inflammation by non-translational regulation of neutrophil function

Interferon-λ (IFN-λ) is a central regulator of mucosal immunity; however, its signaling specificity relative to that of type I interferons is poorly defined. IFN-λ can induce antiviral interferon-stimulated genes (ISGs) in epithelia, while the effect of IFN-λ in non-epithelial cells remains unclear. Here we report that neutrophils responded to IFN-λ. We found that in addition to inducing ISG transcription, IFN-λ (but not IFN-β) specifically activated a translation-independent signaling pathway that diminished the production of reactive oxygen species and degranulation in neutrophils. In mice, IFN-λ was elicited by enteric viruses and acted on neutrophils to decrease oxidative stress and intestinal damage. Thus, IFN-λ acted as a unique immunomodulatory agent by modifying transcriptional and non-translational neutrophil responses, which might permit a controlled development of the inflammatory process.

Type III Interferon-Mediated Signaling Is Critical for Controlling Live Attenuated Yellow Fever Virus Infection In Vivo

Yellow fever virus (YFV) is an arthropod-borne flavivirus, infecting ~200,000 people worldwide annually and causing about 30,000 deaths. The live attenuated vaccine strain, YFV-17D, has significantly contributed in controlling the global burden of yellow fever worldwide. However, the viral and host contributions to YFV-17D attenuation remain elusive. Type I interferon (IFN-α/β) signaling and type II interferon (IFN-γ) signaling have been shown to be mutually supportive in controlling YFV-17D infection despite distinct mechanisms of action in viral infection. However, it remains unclear how type III IFN (IFN-λ) integrates into this antiviral system. Here, we report that while wild-type (WT) and IFN-λ receptor knockout (λR^-/-) mice were largely resistant to YFV-17D, deficiency in type I IFN signaling resulted in robust infection. Although IFN-α/β receptor knockout (α/βR^-/-) mice survived the infection, mice with combined deficiencies in both type I signaling and type III IFN signaling were hypersusceptible to YFV-17D and succumbed to the infection. Mortality was associated with viral neuroinvasion and increased permeability of the blood-brain barrier (BBB). α/βR^-/- λR^-/- mice also exhibited distinct changes in the frequencies of multiple immune cell lineages, impaired T-cell activation, and severe perturbation of the proinflammatory cytokine balance. Taken together, our data highlight that type III IFN has critical immunomodulatory and neuroprotective functions that prevent viral neuroinvasion during active YFV-17D replication. Type III IFN thus likely represents a safeguard mechanism crucial for controlling YFV-17D infection and contributing to shaping vaccine immunogenicity.IMPORTANCE YFV-17D is a live attenuated flavivirus vaccine strain recognized as one of the most effective vaccines ever developed. However, the host and viral determinants governing YFV-17D attenuation and its potent immunogenicity are still unknown. Here, we analyzed the role of type III interferon (IFN)-mediated signaling, a host immune defense mechanism, in controlling YFV-17D infection and attenuation in different mouse models. We uncovered a critical role of type III IFN-mediated signaling in preserving the integrity of the blood-brain barrier and preventing viral brain invasion. Type III IFN also played a major role in regulating the induction of a potent but balanced immune response that prevented viral evasion of the host immune system. An improved understanding of the complex mechanisms regulating YFV-17D attenuation will provide insights into the key virus-host interactions that regulate host immune responses and infection outcomes as well as open novel avenues for the development of innovative vaccine strategies.

A novel method for detection of IFN-lambda 3 binding to cells for quantifying IFN-lambda receptor expression

Type III interferons (IFN-lambdas) are important antiviral cytokines that also modulate immune responses acting through a unique IFN-λR1/IL-10R2 heterodimeric receptor. Conflicting data has been reported for which cells express the IFN-λR1 subunit and directly respond to IFN-λs. In this study we developed a novel method to measure IFN-λ3 binding to IFN-λR1/IL-10R2 on the surface of cells and relate this to a functional readout of interferon stimulated gene (ISG) activity in various cell lines. We show that Huh7.5 hepatoma cells bind IFN-λ3 at the highest levels with the lowest Kd(app), translating to the highest induction of various ISGs. Raji and Jurkat cell lines, representing B and T cells, respectively, moderately bind IFN-λ3 and have lower ISG responses. U937 cells, representing monocytes, did not bind IFN-λ3 well and therefore, did not have any ISG induction. Importantly, knockdown of IFNLR1 in Huh7.5 cells decreased our binding signal proportionally and reduced ISG induction by up to 93%. IFN-λ3 responsiveness increased over time with maximal ISG responses seen at 24h for all but one gene. These data confirm our new IFN-λ3 binding assay can be used to quantify IFN-λ receptor surface expression on a variety of cell types and reflects IFN-λ3 responsiveness.

Peg-Interferon Lambda Treatment Induces Robust Innate and Adaptive Immunity in Chronic Hepatitis B Patients

IFN-lambda (IFNλ) is a member of the type III IFN family and is reported to possess anti-pathogen, anti-cancer, and immunomodulatory properties; however, there are limited data regarding its impact on host immune responses in vivo. We performed longitudinal and comprehensive immunosurveillance to assess the ability of pegylated (peg)-IFNλ to augment antiviral host immunity as part of a clinical trial assessing the efficacy of peg-IFNλ in chronic hepatitis B (CHB) patients. These patients were pretreated with directly acting antiviral therapy (entecavir) for 12 weeks with subsequent addition of peg-IFNλ for up to 32 weeks. In a subgroup of patients, the addition of peg-IFNλ provoked high serum levels of antiviral cytokine IL-18. We also observed the enhancement of natural killer cell polyfunctionality and the recovery of a pan-genotypic HBV-specific CD4⁺ T cells producing IFN-γ with maintenance of HBV-specific CD8⁺ T cell antiviral and cytotoxic activities. It was only in these patients that we observed strong virological control with reductions in both viral replication and HBV antigen levels. Here, we show for the first time that in vivo peg-IFNλ displays significant immunostimulatory properties with improvements in the main effectors mediating anti-HBV immunity. Interestingly, the maintenance in HBV-specific CD8⁺ T cells in the presence of peg-IFNλ is in contrast to previous studies showing that peg-IFNα treatment for CHB results in a detrimental effect on the functionality of this important antiviral T cell compartment.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT01204762.

Interferon Lambda: Modulating Immunity in Infectious Diseases

Interferon lambdas (IFN-λs; IFNL1-4) modulate immunity in the context of infections and autoimmune diseases, through a network of induced genes. IFN-λs act by binding to the heterodimeric IFN-λ receptor (IFNLR), activating a STAT phosphorylation-dependent signaling cascade. Thereby hundreds of IFN-stimulated genes are induced, which modulate various immune functions via complex forward and feedback loops. When compared to the well-characterized IFN-α signaling cascade, three important differences have been discovered. First, the IFNLR is not ubiquitously expressed: in particular, immune cells show significant variation in the expression levels of and susceptibilities to IFN-λs. Second, the binding affinities of individual IFN-λs to the IFNLR varies greatly and are generally lower compared to the binding affinities of IFN-α to its receptor. Finally, genetic variation in the form of a series of single-nucleotide polymorphisms (SNPs) linked to genes involved in the IFN-λ signaling cascade has been described and associated with the clinical course and treatment outcomes of hepatitis B and C virus infection. The clinical impact of IFN-λ signaling and the SNP variations may, however, reach far beyond viral hepatitis. Recent publications show important roles for IFN-λs in a broad range of viral infections such as human T-cell leukemia type-1 virus, rotaviruses, and influenza virus. IFN-λ also potentially modulates the course of bacterial colonization and infections as shown for Staphylococcus aureus and Mycobacterium tuberculosis. Although the immunological processes involved in controlling viral and bacterial infections are distinct, IFN-λs may interfere at various levels: as an innate immune cytokine with direct antiviral effects; or as a modulator of IFN-α-induced signaling via the suppressor of cytokine signaling 1 and the ubiquitin-specific peptidase 18 inhibitory feedback loops. In addition, the modulation of adaptive immune functions via macrophage and dendritic cell polarization, and subsequent priming, activation, and proliferation of pathogen-specific T- and B-cells may also be important elements associated with infectious disease outcomes. This review summarizes the emerging details of the IFN-λ immunobiology in the context of the host immune response and viral and bacterial infections.

Type III Interferons in Hepatitis C Virus Infection

The interferon (IFN)-λ family of type III cytokines includes the closely related interleukin (IL)-28A (IFN-λ2), IL-28B (IFN-λ3), and IL-29 (IFN-λ1). They signal through the Janus kinases (JAK)-signal transducers and activators of transcription pathway and promote an antiviral state by the induction of expression of several interferon-stimulated genes (ISGs). Contrary to type I IFNs, the effect of IFN-λ cytokines is largely limited to epithelial cells due to the restricted pattern of expression of their specific receptor. Several genome-wide association studies have established a strong correlation between polymorphism in the region of IL-28B gene (encoding for IFN-λ3) and both spontaneous and therapeutic IFN-mediated clearance of hepatitis C virus (HCV) infection, but the mechanism(s) underlying this enhanced viral clearance are not fully understood. IFN-λ3 directly inhibits HCV replication, and in vitro studies suggest that polymorphism in the IFN-λ3 and its recently identified overlapping IFN-λ4 govern the pattern of ISGs induced upon HCV infection of hepatocytes. IFN-λ can also be produced by dendritic cells, and apart from its antiviral action on hepatocytes, it can regulate the inflammatory response of monocytes/macrophages, thus acting at the interface between innate and adaptive immunity. Here, we review the current state of knowledge about the role of IFN-λ cytokines in mediating and regulating the immune response during acute and chronic HCV infections.

Combination of Adt-O1Manisa and Ad5-boIFNλ3 induces early protective immunity against foot-and-mouth disease in cattle

Foot-and-mouth-disease (FMD) remains the most infectious livestock disease worldwide. Although commercially available inactivated or adenovirus-vectored-vaccines (Ad5-FMD) are effective, they require 5-7 days to induce protection. Therefore, new control strategies that stimulate rapid immune responses are needed. Expression of bovine interferon λ3 using the Ad5-vector platform (Ad5-boIFNλ3) is able to delay disease in cattle, but clinical signs appear at 9 days after challenge. We hypothesized that combination of Ad5-boIFNλ3 and Ad5-FMD could induce immediate and lasting protection against FMD. Cattle were vaccinated with an Ad5-FMD, Ad5-boIFNλ3, or the combination of both, followed by challenge at three days post-immunization. All animals treated with Ad5-FMD combined with Ad5-boIFNλ3 were fully protected against FMD, despite the absence of systemic neutralizing antibodies or antiviral activity at the time of challenge. Induction of a strong cell-mediated immune response suggested that Ad5-boIFNλ3 is able to act as an adjuvant of Ad5-FMD vaccine in cattle.

IFNλ is a potent anti-influenza therapeutic without the inflammatory side effects of IFNα treatment

Influenza A virus (IAV)‐induced severe disease is characterized by infected lung epithelia, robust inflammatory responses and acute lung injury. Since type I interferon (IFNαβ) and type III interferon (IFNλ) are potent antiviral cytokines with immunomodulatory potential, we assessed their efficacy as IAV treatments. IFNλ treatment of IAV‐infected Mx1‐positive mice lowered viral load and protected from disease. IFNα treatment also restricted IAV replication but exacerbated disease. IFNα treatment increased pulmonary proinflammatory cytokine secretion, innate cell recruitment and epithelial cell death, unlike IFNλ‐treatment. IFNλ lacked the direct stimulatory activity of IFNα on immune cells. In epithelia, both IFNs induced antiviral genes but no inflammatory cytokines. Similarly, human airway epithelia responded to both IFNα and IFNλ by induction of antiviral genes but not of cytokines, while hPBMCs responded only to IFNα. The restriction of both IFNλ responsiveness and productive IAV replication to pulmonary epithelia allows IFNλ to limit IAV spread through antiviral gene induction in relevant cells without overstimulating the immune system and driving immunopathology. We propose IFNλ as a non‐inflammatory and hence superior treatment option for human IAV infection.

Genetically engineered Newcastle disease virus expressing human interferon-λ1 induces apoptosis in gastric adenocarcinoma cells and modulates the Th1/Th2 immune response

Interferon-λ1 (IFN-λ1), a recently discovered cytokine of the type III IFN family, was found to be a therapeutic alternative to type I IFN in terms of tumors. Using reverse genetics technique, we generated a recombinant Newcastle disease virus (NDV) LaSota strains named as human IFN‑λ1 recombinant adenovirus (rL-hIFN-λ1) containing human IFN-λ1 gene and further evaluated the expressing of IFN-λ1 in human gastric adenocarcinoma cell line SGC-7901 after infected with rL-hIFN-λ1 by using western blot analysis, RT-PCR and immunofluorescence analyses. IFN-λl specific receptor IFNLR1 was detected on several gastric tumor cell lines including SGC-7901 and AGS and on PBMCs.The expression of the IFN-λ1 proteins reached a high level detected in the supernatant harvested 24 h after the infection of tumor cells. The proliferation changes of SGC infected with rL-hIFN-λ1 was significantly inhibited compared with NDV-infected group. Apoptosis was significantly induced by rL-hIFN-λ1 in gastric cancer cells compared with NDV virus tested by TUNEL assay, western blot analysis and Annexin V flow cytometry. Due to the high dose of IFN-λ1 expressed by the rL-hIFN-λ1-infected tumor cells, the immune study showed that rL-hIFN-λ1 increased IFN-γ production [the T helper cell subtype 1 (Th1) response] and inhibited interleukin (IL)-13 production [the T helper cell subtype 2 (Th2) response] to change the Th1/Th2 response of tumor microenvironment which inhibited tumor growth. This study aims at building recombinant NDV rL-hIFN-λ1 as an efficient antitumor agent.

Evolution of IFN-λ in tetrapod vertebrates and its functional characterization in green anole lizard (Anolis carolinensis)

IFN-λ (IFNL), i.e. type III IFN genes were found in a conserved gene locus in tetrapod vertebrates. But, a unique locus containing IFNL was found in avian. In turtle and crocodile, IFNL genes were distributed in these two separate loci. As revealed in phylogenetic trees, IFN-λs in these two different loci and other amniotes were grouped into two different clades. The conservation in gene presence and gene locus was also observed for the receptors of IFN-λ, IFN-λR1 and IL-10RB in tetrapods. It is further revealed that in North American green anole lizard Anolis carolinensis, a single IFNL gene was situated collinearly in the conserved locus as in other tetrapods, together with its receptors IFN-λR1 and IL-10RB also identified in this study. The IFN-λ and its receptors were expressed in all examined organs/tissues, and their expression was stimulated following the injection of polyI:polyC. The ISREs in promoter of IFN-λ in lizard were responsible to IRF3 as demonstrated using luciferase report system, and IFN-λ in lizard functioned through the receptors, IFN-λR1 and IL-10RB, as the up-regulation of ISGs was observed in ligand-receptor transfected, and also in recombinant IFN-λ stimulated, cell lines. Taken together, it is concluded that the mechanisms involved in type III IFN ligand-receptor system, and in its signalling pathway and its down-stream genes may be conserved in green anole lizard, and may even be so in tetrapods from xenopus to human.

Interleukin-29 Enhances Synovial Inflammation and Cartilage Degradation in Osteoarthritis

We have recently shown that IL-29 was an important proinflammatory cytokine in pathogenesis of rheumatoid arthritis (RA). Inflammation also contributes to the pathogenesis of osteoarthritis (OA). The aim of this study was to investigate the effect and mechanism of IL-29 on cytokine production and cartilage degradation in OA. The mRNA levels of IL-29 and its specific receptor IL-28Ra in peripheral blood mononuclear cells (PBMCs) were significantly increased in OA patients when compared to healthy controls (HC). In the serum, IL-29 protein levels were higher in OA patients than those in HC. Immunohistochemistry revealed that both IL-29 and IL-28Ra were dramatically elevated in OA synovium compared to HC; synovial fibroblasts (FLS) and macrophages were the main IL-29-producing cells in OA synovium. Furthermore, recombinant IL-29 augmented the mRNA expression of IL-1β, IL-6, IL-8, and matrix-metalloproteinase-3 (MMP-3) in OA FLS and increased cartilage degradation when ex vivo OA cartilage explant was coincubated with OA FLS. Finally, in OA FLS, IL-29 dominantly activated MAPK and nuclear factor-κB (NF-κB), but not Jak-STAT and AKT signaling pathway as examined by western blot. In conclusion, IL-29 stimulates inflammation and cartilage degradation by OA FLS, indicating that this cytokine is likely involved in the pathogenesis of OA.

Murine gammaherpesvirus targets type I IFN receptor but not type III IFN receptor early in infection

The innate immune response represents a primary line of defense against invading viral pathogens. Since epithelial cells are the primary site of gammaherpesvirus replication during infection in vivo and there are no information on activity of IFN-III signaling against gammaherpesviruses in this cell type, in present study, we evaluated the expression profile and virus-host interactions in mouse mammary epithelial cell (NMuMG) infected with three strains of murine gammaherpesvirus, MHV-68, MHV-72 and MHV-4556. Studying three strains of murine gammaherpesvirus, which differ in nucleotide sequence of some structural and non-structural genes, allowed us to compare the strain-dependent interactions with host organism. Our results clearly demonstrate that: (i) MHV-68, MHV-72 and MHV-4556 differentially interact with intracellular signaling and dysregulate IFN signal transduction; (ii) MHV-68, MHV-72 and MHV-4556 degrade type I IFN receptor in very early stages of infection (2-4hpi), but not type III IFN receptor; (iii) type III IFN signaling might play a key role in antiviral defense of epithelial cells in early stages of murine gammaherpesvirus replication; (iv) NMuMG cells are an appropriate model for study of not only type I IFN signaling, but also type III IFN signaling pathway. These findings are important for better understanding of individual virus-host interactions in lytic as well as in persistent gammaherpesvirus replication and help us to elucidate IFN-III function in early events of virus infection.

Impact of host genetic polymorphisms on vaccine induced antibody response

Many host- and vaccine-specific factors modulate an antibody response. Host genetic polymorphisms, in particular, modulate the immune response in multiple ways on different scales. This review article describes how information on host genetic polymorphisms and corresponding immune cascades may be used to generate personalized vaccine strategies to optimize the antibody response.

IFNλ Stimulates MxA Production in Human Dermal Fibroblasts via a MAPK-Dependent STAT1-Independent Mechanism

IFNλ is important for epidermal defense against viruses. It is produced by, and acts on, keratinocytes, whereas fibroblasts were previously considered to be unresponsive to this type III IFN. Herein we report findings revealing cell type-specific differences in IFNλ signaling and function in skin resident cells. In dermal fibroblasts, IFNλ induced the expression of myxovirus protein A (MxA), a potent antiviral factor, but not other IFN signature genes as it does in primary keratinocytes. In contrast to its effect on keratinocytes, IFNλ did not phosphorylate signal transducer and activator of transcription 1 in fibroblasts, but instead activated mitogen activated protein kinases (MAPK). Accordingly, inhibition of MAPK activation (p38 and p42/44) blocked the expression of MxA protein in fibroblasts but not in keratinocytes. Functionally, IFNλ inhibited proliferation in keratinocytes but not in fibroblasts. Moreover, IFNλ upregulated the expression of Tumor growth factor beta 1 (TGFβ1)-induced collagens in fibroblasts. Taken together, our findings identify primary human dermal fibroblasts as responder cells to IFNλ. Our study shows cutaneous cell type-specific IFN signaling and suggests that IFNλ, although important for epidermal antiviral competence, may also have a regulatory role in the dermal compartment balancing type I IFN-induced inhibition of tissue repair processes.

Dexamethasone decreases IL-29 expression in house dust mite-stimulated human bronchial epithelial cells

The aim of this study was to explore the effect of IL-29 on the progression of airway allergic disease by detecting the level of IL-29 in airway allergic cell models stimulated by house dust mite (HDM) in the presence or absence of dexamethasone (DEX). The same batch of human bronchial epithelial cells in exponential growth phase was randomly divided into five groups: blank group (A), 300 ng/mL HDM group (B), 1000 ng/mL HDM group (C), 3000 ng/mL HDM group (D), and 300 ng/mL HDM+100 ng/mL DEX group (E). The IL-29 mRNA expression was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The IL-29 protein expression in cell suspension was detected by ELISA. The results showed that after stimulation with HDM for 24 h, the expression of IL-29 was increased significantly, and after co-stimulation with HDM and DEX for 24 h, the expression of IL-29 in group E was significantly lower than that in the groups stimulated by HDM alone but higher than that in the group A. The differences between the different groups were significant (F=132.957, P<0.01). Additionally, the higher the concentration of HDM was, the more significant the increase in the IL-29 expression was. In conclusion, IL-29 may play a role in the progression of airway allergic disease including asthma.

Interleukin-29 induces receptor activator of NF-κB ligand expression in fibroblast-like synoviocytes via MAPK signaling pathways

AIM

We previously reported that interleukin-29 (IL-29) was highly expressed in the blood and synovium of rheumatoid arthritis (RA) patients and contributed to synovial inflammation by induction of proinflammatory cytokine production. Given chronic inflammation can trigger the process of bone erosion, and receptor activator of nuclear factor-κB ligand (RANKL) plays a crucial role in bone erosion of RA, we hypothesize that IL-29 mediates bone erosion in RA by regulation of RANKL expression. Here, we investigated the effect of IL-29 on RANKL expression in RA fibroblast-like synoviocytes (FLS) and the relevant signaling pathways involved in it.

METHODS

Primary fibroblast cells isolated from RA patients were stimulated by recombinant IL-29 in the presence or absence of anti-IL-29 antibody, and the expression levels of RANKL were assessed using real-time polymerase chain reaction and immunostaining. Furthermore, the IL-29 signaling pathway for regulation of RANKL was also examined by Western blotting assay.

RESULTS

IL-29 upregulated RANKL expression in a dose-dependent manner, and blockade of IL-29 resulted in a significantly reduced RANKL expression in RA-FLS. Incubation RA-FLS with IL-29 (100 ng/mL) led to phosphorylation of ERK (extracellular signal-regulated kinase), p38 and JNK (c-Jun N-terminal kinase). The expression of RANKL induced by IL-29 could be completely blocked by the inhibitors of mitogen-activated protein kinase (MAPK) signal pathway, including PD98059 (ERK inhibitor), SB203580 (p38 inhibitor) and SP600125 (JNK inhibitor).

CONCLUSION

These findings indicate, for the first time, that IL-29 could directly induce RANKL expression in RA-FLS via MAPK signaling pathway, suggesting IL-29 might be a new target in the prevention of joint destruction in RA.

Evaluation of anti-asthmatic and antioxidant potential of Boerhavia procumbens in toluene diisocyanate (TDI) treated rats

AIM OF THE STUDY

Asthma is an ailment of airways characterized by activation of the T helper (Th) 2 lymphocytes and subsequent movement of inflammatory cells. Boerhavia procumbens of family Nyctaginaceae is locally used for the treatment of asthma, cough, hemorrhoids, dropsy, cardiac, eyes and kidney problems. We have evaluated its methanol extract (BPM) as a therapeutic candidate for asthma against toluene diisocyanate (TDI) allergic model in rat. The BPM extract was obtained from the whole plant of B. procumbens in methanol. Sprague-Dawley male 36 rats (200-250 g) were categorized into 6 groups having six rats in each category. The animals were provoked (10%) and sensitized (5%) by TDI. Animals of groups I-III were vehicle control (ethyl acetate), diseased control (TDI) and reference control (TDI+dexamethasone {2.5mg/kg bw}), respectively. Animals of group IV (TDI+200mg/kg bw) and group V (TDI+400mg/kg bw) were administered with BPM whereas group VI was administered with 400mg/kg bw alone of BPM. Protective effects of BPM were determined by counting the number of leucocytes and estimation of interleukines in blood, bronchoalveolar lavage (BAL) and in in vitro culture of spleen cells. Estimation of antioxidant enzymes, lipid peroxides and H2O2 and histopathology of lungs were carried out for antioxidant potential of plant extract used.

RESULTS

Methanol extract of B. procumbens suppressed the asthmatic symptoms and inhibited the infiltration of eosinophils and lymphocytes in lungs of TDI provoked rats. Administration of BPM to TDI provoked rats, dose dependently, inhibited the release of interleukins (IL)-2 in serum and IL-4, IL-6 interferon gamma (IFN-γ) in bronchoalveolar lavage (BAL) and in in vitro culture of spleen cells, and ameliorated the oxidative stress in lung tissues. Quantitative scoring of the lung histopathology exhibited protective effects of BPM and the inflammation, mucus, thickening of peribronchial smooth muscle layer and subepithelial deposition of collagen induced with TDI were ameliorated. The BPM has the anti-inflammatory properties that may be used to treat the asthma and inflammatory related ailments.

Interferon at the crossroads of allergy and viral infections

IFN-α/β was first described as a potent inhibitor of viral replication, but it is now appreciated that IFN signaling plays a pleiotropic role in regulating peripheral T cell functions. Recently, IFN-α/β was shown to block human Th2 development by suppressing the transcription factor GATA3. This effect is consistent with the role for IFN-α/β in suppressing allergic inflammatory processes by blocking granulocyte activation and IL-4-mediated B cell isotype switching to IgE. With the consideration of recent studies demonstrating a defect in IFN-α/β secretion in DCs and epithelial cells from individuals with severe atopic diseases, there is an apparent reciprocal negative regulatory loop in atopic individuals, whereby the lack of IFN-α/β secretion by innate cells contributes to the development of allergic Th2 cells. Is it possible to overcome these events by treating with IFN-α/β or by inducing its secretion in vivo? In support of this approach, case studies have documented the therapeutic potential of IFN-α/β in treating steroid-resistant allergic asthma and other atopic diseases. Additionally, individuals with asthma who are infected with HCV and respond to IFN therapy showed a reduction in symptoms and severity of asthma attacks. These findings support a model, whereby allergic and antiviral responses are able to cross-regulate each other, as IgER cross-linking of pDCs prevents IFN-α/β production in response to viral infection. The clinical importance of upper-respiratory viruses in the context of allergic asthma supports the need to understand how these pathways intersect and to identify potential therapeutic targets.

Guarding the frontiers: the biology of type III interferons

Type III interferons (IFNs) or IFN-λs regulate a similar set of genes as type I IFNs, but whereas type I IFNs act globally, IFN-λs primarily target mucosal epithelial cells and protect them against the frequent viral attacks that are typical for barrier tissues. IFN-λs thereby help to maintain healthy mucosal surfaces through immune protection, without the significant immune-related pathogenic risk associated with type I IFN responses. Type III IFNs also target the human liver, with dual effects: they induce an antiviral state in hepatocytes, but specific IFN-λ4 action impairs the clearance of hepatitis C virus and could influence inflammatory responses. This constitutes a paradox that has yet to be resolved.

Interferon-λ: Immune Functions at Barrier Surfaces and Beyond

When type III interferon (IFN-λ; also known as interleukin-28 [IL-28] and IL-29) was discovered in 2003, its antiviral function was expected to be analogous to that of type I IFNs (IFN-α and IFN-β) via the induction of IFN-stimulated genes (ISGs). Although IFN-λ stimulates expression of antiviral ISGs preferentially in cells of epithelial origin, recent studies have defined additional antiviral mechanisms in other cell types and tissues. Viral infection models using mice lacking IFN-λ signaling and SNP associations with human disease have expanded our understanding of the contribution of IFN-λ to the antiviral response at anatomic barriers and the immune response beyond these barriers. In this review, we highlight recent insights into IFN-λ functions, including its ability to restrict virus spread into the brain and to clear chronic viral infections in the gastrointestinal tract. We also discuss how IFN-λ modulates innate and adaptive immunity, autoimmunity, and tumor progression and its possible therapeutic applications in human disease.

Interferons and systemic sclerosis: correlation between interferon gamma and interferon-lambda 1 (IL-29)

BACKGROUND

Interferon (IFN)-λ1 is a newly described cytokine, member of type III interferons family, which is known for its antiviral, anti-proliferative and antitumor activity. Recent studies indicated that this cytokine has also immune-regulatory function, but its role in the pathogenesis of autoimmune diseases is not established yet. We evaluated serum levels of IFN-λ1 in systemic sclerosis (SSc) patients and healthy controls and its association with IFN-γ and clinical manifestations.

METHODS

IFN-λ1 and IFN-γ serum levels were measured by ELISA from 52 patients with SSc and 53 healthy controls. Association of cytokines serum levels was sought with clinical parameters.

RESULTS

IFN-λ1 and IFN-γ levels in SSc patients were significantly higher than those in healthy individuals (24.82 ± 8.78 and 11.04 ± 3.04 pg/ml, p < 0.0001; 34.11 ± 8.11 and 10.73 ± 2.77 pg/ml, p < 0.0001, respectively). We found a positive correlation between IFN-λ1 and IFN-γ levels in SSc patients (p = 0.0103, r = 0.3526). IFN-γ levels were associated with muscle involvement (p = 0.0483).

CONCLUSION

We first showed raised IFN-λ1 levels in SSc patients. Furthermore, we found a correlation between IFN-λ1 and IFN-γ levels and an association between IFN-γ and myositis. Additional in vitro and in vivo studies are needed to understand IFN-λ1 role in SSc.

Investigations of interferon-lambda for the treatment of cancer

Interferon-lambda (IFN-λ), a recently discovered cytokine, overlaps broadly with type I IFN signaling, producing antiviral, antiproliferative, and proapoptotic responses. In comparison to type I IFNs, IFN-λ has a limited spectrum of responsive tissues due to variation in expression of the IFN-λ receptor IFNLR1. Type I IFNs have been investigated for their antitumor effects and used in the clinical setting for a number of different cancers. Given the overlap in signaling and function between IFN-λ and type I IFNs, IFN-λ has also drawn interest for the treatment of cancer. To date, a number of studies using both murine and human models of cancer have investigated the antitumor effects of IFN-λ. These studies have found that IFN-λ is capable of directly targeting cancer cells to reduce their tumorigenicity, induce cell cycle arrest, and cause apoptosis. In addition, IFN-λ has been shown to have indirect effects against cancer cells through immune system responses and immune modulatory effects. This review aims to detail the findings of studies investigating IFN-λ for the treatment of cancer as well as suggest areas of potential interest for future studies.