Novel interferon-lambdas induce antiproliferative effects in neuroendocrine tumor cells

New treatment alternatives for primary and metastatic colorectal cancer by an integrated transcriptome and network analyses

Metastatic colorectal cancer (CRC) is still in need of effective treatments. This study applies a holistic approach to propose new targets for treatment of primary and liver metastatic CRC and investigates their therapeutic potential in-vitro. An integrative analysis of primary and metastatic CRC samples was implemented for alternative target and treatment proposals. Integrated microarray samples were grouped based on a co-expression network analysis. Significant gene modules correlated with primary CRC and metastatic phenotypes were identified. Network clustering and pathway enrichments were applied to gene modules to prioritize potential targets, which were shortlisted by independent validation. Finally, drug-target interaction search led to three agents for primary and liver metastatic CRC phenotypes. Hesperadin and BAY-1217389 suppress colony formation over a 14-day period, with Hesperadin showing additional efficacy in reducing cell viability within 48 h. As both candidates target the G2/M phase proteins NEK2 or TTK, we confirmed their anti-proliferative properties by Ki-67 staining. Hesperadinin particular arrested the cell cycle at the G2/M phase. IL-29A treatment reduced migration and invasion capacities of TGF-β induced metastatic cell lines. In addition, this anti-metastatic treatment attenuated TGF-β dependent mesenchymal transition. Network analysis suggests IL-29A induces the JAK/STAT pathway in a preventive manner.

Interleukin 28A aggravates Con A-induced acute liver injury by promoting the recruitment of M1 macrophages

Immune-mediated acute hepatic injury is characterized by the destruction of a large number of hepatocytes and severe liver function damage. Interleukin-28A (IL-28A), a member of the IL-10 family, is notable for its antiviral properties. However, despite advances in our understanding of IL-28A, its role in immune-mediated acute injury remains unclear. The present study investigated the role of IL-28A in concanavalin A (Con A)-induced acute immune liver injury. After Con A injection in mice, IL-28A level significantly increased. IL-28A deficiency was found to protect mice from acute liver injury, prolong survival time, and reduce serum aspartate aminotransferase and alanine aminotransferase levels. In contrast, recombinant IL-28A aggravated liver injury in mice. The proportion of activated M1 macrophages was significantly lower in the IL-28A-deficiency group than in the wild-type mouse group. In adoptive transfer experiments, M1 macrophages from WT could exacerbate mice acute liver injury symptoms in the IL-28A deficiency group. Furthermore, the expression of proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), IL-12, IL-6, and IL-1β, by M1 macrophages decreased significantly in the IL-28A-deficiency group. Western blotting demonstrated that IL-28A deficiency could limit M1 macrophage polarization by modulating the nuclear factor (NF)-κB, mitogen-activated protein kinase (MAPK), and interferon regulatory factor (IRF) signaling pathways. In summary, IL-28A deletion plays an important protective role in the Con A-induced acute liver injury model and IL-28A deficiency inhibits the activation of M1 macrophages by inhibiting the NF-κB, MAPK, and IRF signaling pathways. These results provide a potential new target for the treatment of immune-related hepatic injury.

In HIV-Infected Immunological Non-Responders, Hepatitis C Virus Eradication Contributes to Incomplete Normalization of Systemic Inflammation Indexes, but Does Not Lead to Rapid CD4+ T-Cell Count Recovery

In HIV-positive individuals taking antiretroviral therapy, coinfection with hepatitis C virus (HCV) increases systemic inflammation, which interferes with the CD4+ T-cells regeneration. This study evaluated the effect of HCV eradication on systemic inflammation and CD4+ T-cell regeneration in patients who gave poor response to antiretroviral therapy, the so-called "immunological non-responders" (INRs). HIV-infected patients who received a course of direct-acting antivirals for treating hepatitis C were examined. The control groups included HIV/HCV-coinfected INRs and relatively healthy volunteers. It was established for the first time that HCV eradication is not accompanied by a complete suppression of systemic inflammation, but improves the T-cell pool composition: in INRs, the blood CD4+/CD8+ T-lymphocyte ratio increases and approaches those of healthy individuals. Apparently, in INRs treated for hepatitis C, the immune system recovery takes time and may be incomplete.

Enhanced soluble expression of active recombinant human interleukin-29 using champion pET SUMO system

Current research focuses on the soluble and high-level expression of biologically active recombinant human IL-29 protein in Escherichia coli. The codon-optimized IL-29 gene was cloned into the Champion™ pET SUMO expression system downstream of the SUMO tag under the influence of the T7 lac promoter. The expression of SUMO-fused IL-29 protein was compared in E. coli Rosetta 2(DE3), Rosetta 2(DE3) pLysS, and Rosetta-gami 2(DE3). The release of the SUMO fusion partner resulted in approximately 98 mg of native rhIL-29 protein with a purity of 99% from 1 l of fermentation culture. Purified rhIL-29 was found to be biologically active, as evaluated by its anti-proliferation assay. It was found that Champion™ pET SUMO expression system can be used to obtained high yield of biologically active soluble recombinant human protein compared to other expression vector.

Interleukin-28A induces epithelial barrier dysfunction in CD patient-derived intestinal organoids

Intestinal barrier dysfunction is a pathogenic hallmark in Crohn's disease (CD). Identifying key players that regulate intestinal barrier may provide novel leads for therapeutic intervention. Interleukin-28A (IL-28A) is a newly identified IL-10/interferon cytokine family member, with its most implicated function being antiviral and anti-proliferative properties. However, the role and underlying mechanisms of IL-28A in the regulation of epithelial barrier in CD remain so far unexplored. IL-28A levels were measured in the plasma and biopsies of CD patients and healthy subjects. CD patient-derived intestinal organoids were characterized by differentiation gene markers and then exposed to TNF-α, IFN-γ, IL-1β or LPS, or IL-28A with or without GLPG0634 (filgotinib). Epithelial permeability was assessed by FITC-D4 flux. Expression of junctional components was analyzed by qRT-PCR, immunofluorescence staining, or Western blotting. JAK-STAT activity was analyzed by Western blotting. IL-28A levels were significantly increased in the plasma and biopsies from active patients with CD as compared with healthy subjects. IL-28A and its receptor complex IL-28AR/IL-10R2 were detected in CD patient-derived intestinal organoids and showed a selective response to IFN-γ exposure. IL-28A triggered epithelial barrier disruption and accompanied by reduced ZO-1 and E-cadherin expression. This effect was mediated by JAK-STAT1 pathway. Pre-incubation with the JAK1 inhibitor filgotinib ameliorated the barrier dysfunction induced by IL-28A. These results identified IL-28A as a novel regulator of epithelial barrier function and could be a putative target for CD treatment. We provide novel basic evidence that restoring intestinal barrier is a potential mechanism that contributes to the clinical benefits of JAK1 inhibitor in patients with CD.NEW & NOTEWORTHY IL-28A levels were significantly increased in the plasma and biopsies from active patients with CD as compared with healthy subjects. IFN-γ exposure stimulated IL-28A expression in intestinal organoids. Partially mimicking the effect of IFN-γ, IL-28A impaired epithelial barrier function and disrupted junctional components through the activation of JAK-STAT1 signaling, whereas JAK1 inhibitor ameliorated the above-mentioned effects of IL-28A. These findings highlight the newly identified cytokine IL-28A as a novel contributor to CD pathogenesis and could be a putative target for CD treatment. We also provide new evidence for potential applications of JAK inhibition in CD therapy.

Association of TNFRSF1A and IFNLR1 Gene Polymorphisms with the Risk of Developing Breast Cancer and Clinical Pathologic Features

Several genes have been associated with breast cancer (BC) susceptibility. The tumor necrosis factor receptor superfamily, member 1A (TNFRSF1A), and interferon lambda receptor 1 (IFNLR1) genes encode receptors that mediate the action of inflammatory cytokines. Previous studies have demonstrated the association of the variants rs1800693 (TNFRSF1A) and rs4649203 (IFNLR1) with some inflammatory diseases. The present study aimed to verify a possible association of these variants with BC, its clinical pathologic features, as well as epidemiological data in a Brazilian population. A total of 243 patients and 294 individuals without history of BC were genotyped for these polymorphisms through TaqMan® SNP genotyping assays by qPCR. For the TNFRSF1A gene, no significant results were found. For IFNLR1, the AA genotype (p = 0.008) and the A allele (p = 0.02) were significantly associated with a lower risk of developing BC. When analyzing the age, it was observed that each increase of one year contributes to the development of BC (p < 0.001). Also, the smoking habit (p < 0.001) and body mass index (p = 0.018) increase the risk of disease development. Analyzing progesterone receptor factor an association was found with the AA genotype of the IFNLR1 (p = 0.02). The findings suggest that polymorphism in the immune-related IFNLR1 gene contribute to BC susceptibility in a Brazilian population. These findings can contribute to the further understanding of the role this gene and pathways in BC development.

Interferon-Lambda 1 Inhibits Staphylococcus aureus Colonization in Human Primary Keratinocytes

Atopic dermatitis (AD) is a common inflammatory skin disease. Staphylococcus aureus (S. aureus) colonization in skin lesions occurs in approximately 70% of AD patients. It has been found that IFN-λ1 can inhibit the colonization of S. aureus in normal human nasal mucosa. IFN-λ1 can increase IL-28RA in infected human keratinocytes. In this study, we found that IFN-λ1 can increase mRNA expression of FLG and antimicrobial peptides (AMPs) and inhibit TSLP mRNA expression in infected human keratinocytes. IFN-λ1 can increase intracellular ROS level, decrease STAT1 phosphorylation, and inhibit the colonization of S. aureus in human primary keratinocytes. These effects were attenuated by knocking-down IL-28R and NADPH oxidase inhibitor, suggesting that this function was mediated by JAK-STAT1 signaling pathway. These results suggest that IFN-λ1 might have an inhibitory effect on S. aureus colonization in AD lesions. Our findings might have potential value in the treatment for AD.

The pros and cons of interferons for oncolytic virotherapy

Interferons (IFN) are potent immune stimulators that play key roles in both innate and adaptive immune responses. They are considered the first line of defense against viral pathogens and can even be used as treatments to boost the immune system. While viruses are usually seen as a threat to the host, an emerging class of cancer therapeutics exploits the natural capacity of some viruses to directly infect and kill cancer cells. The cancer-specificity of these bio-therapeutics, called oncolytic viruses (OVs), often relies on defective IFN responses that are frequently observed in cancer cells, therefore increasing their vulnerability to viruses compared to healthy cells. To ensure the safety of the therapy, many OVs have been engineered to further activate the IFN response. As a consequence of this IFN over-stimulation, the virus is cleared faster by the immune system, which limits direct oncolysis. Importantly, the therapeutic activity of OVs also relies on their capacity to trigger anti-tumor immunity and IFNs are key players in this aspect. Here, we review the complex cancer-virus-anti-tumor immunity interplay and discuss the diverse functions of IFNs for each of these processes.

Interferons: role in cancer therapy

Interferons (IFNs) are a group of signaling cytokines, secreted by host cells to induce protection against various disorders. IFNs can directly impact on tumor cells or indirectly induce the immune system to protect host cells. The expression levels of IFNs and its functions of are excellently modulated in a way to protect host cells from probable toxicities caused by extreme responses. The efficacy of anticancer therapies is correlated to IFNs signaling. Although IFN signaling is involved in induction of antitumor responses, chronic stimulation of the IFN signaling pathway can induce resistance to various antineoplasm therapies. Hence, IFNs are expressed by both cancer and immune cells, and modulate their biological function. Understanding this mechanism of action might be a key target of combination therapies.

Association between IL28B Polymorphisms and Outcomes of Hepatitis B Virus Infection: A meta-analysis

BACKGROUND

Interleukin (IL) 28B polymorphisms encoding pro-inflammatory and anti-inflammatory cytokines trigger diverse clinical outcome of hepatitis virus infection. However, there is controversy concerning the association of IL28B polymorphisms with the outcome of hepatitis B virus (HBV) infection, with several studies obtaining inconsistent results. We performed a meta-analysis to evaluate the role of 3 single nucleotide polymorphisms (SNPs) rs12979860, rs12980275 and rs8099917 in the progression of HBV infection, overall and by ethnicity.

METHODS

Searched PubMed, Embase and Wiley Online Library electronic databases using 'interleukin 28B', 'IL 28B', 'IL 28B polymorphism', 'hepatitis B virus', 'HBV', and performed meta- analysis for rs12979860, rs12980275 and rs8099917 in Asian and Caucasian populations under the dominant recessive and allele model.

RESULTS

Eighteen studies were found in total and used for this meta-analysis, including 5587 cases and 4295 controls. The IL28B polymorphism rs12979860 had no association with HBV persistence (CC vs CT + TT: OR = 0.86, 95% CI = 0.76-1.00; TT vs CT + CC: OR = 1.14, 95% CI = 0.76-1.70; T vs C: OR = 1.03, 95% CI = 0.94-1.13). Similarly, neither rs12980275 nor rs8099917 had associations with HBV persistence (rs12980275 in AA vs AG + AA: OR = 1.15, 95% CI = 0.96-1.38; rs8099917 in TT vs GT + GG: OR = 1.15, 95% CI = 0.96-1.39). There was also no significant association of IL28B polymorphisms with persistent HBV infection in Asians or Chinese. There was no evidence of an association of rs12979860 with the HBV-related hepatocellular carcinoma susceptibility (T vs C: OR = 1.53, 95% CI = 0.96-2.43).

CONCLUSION

IL28B polymorphisms had no association with the outcome of HBV infection overall, nor in the Asians and the Chinese. These 3 SNPs might not be relevant to the development of HBV infection.

The tumor immune microenvironment in gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are a group of rare tumors that are increasing in prevalence. The complex tumor immune microenvironment (TIME) plays an important role in tumor development and the response to immunotherapy but is poorly understood. In this review, the components of the TIME are described in detail, including discussion about infiltrating immune cells, the immune checkpoint system, the cytokine and chemokine milieu, and immunomodulatory factors. Moreover, a comparison between TIMEs among different types of GEP-NENs and the interplay among the TIME, tumor cells, and the stromal microenvironment is described. Novel treatment options for GEP-NENs and potential biomarkers for the immune response are also characterized. We provide a comprehensive generalized review of the TIME that can inform GEP-NEN treatment strategies.

IL28RA inhibits human epidermal keratinocyte proliferation by inhibiting cell cycle progression

Interleukin (IL) 28 receptor α (IL28RA) is a well-known candidate for psoriasis susceptibility based on previous genome-wide association study (GWAS) analysis. However, the function of IL28RA in psoriasis has not been elucidated. In the present study, the expression of IL28RA was significantly decreased in lesional tissues from patients with plaque psoriasis when compared with the expression observed in adjacent non-lesional tissues. In vitro studies further demonstrated that in the presence of IL-29, HaCaT keratinocytes with IL28RA knockdown exhibited a faster rate of proliferation than control cells, and an enhanced ratio of cells in the S and G2/M phase. By contrast, IL28RA overexpression inhibited the proliferation of HaCaT keratinocytes and caused cell cycle arrest at the G0/G1 phases. Western blot analysis revealed that knockdown of IL28RA upregulated cyclinB1 expression and downregulated cyclinE expression; the opposite results were observed in the IL28RA-overexpressing HaCaT cells. Finally, a mechanistic study revealed that IL28RA functions through the activation of the Janus kinase-signal transducer and activator of transcription signaling pathway to exert its anti-proliferative effect. These results suggested that weak expression of IL28RA may contribute to the pathogenesis of psoriasis and that IL28RA may be an effective drug target for the treatment of psoriasis. However, further in vivo studies are required.

Targeting IL-10 Family Cytokines for the Treatment of Human Diseases

Members of the interleukin (IL)-10 family of cytokines play important roles in regulating immune responses during host defense but also in autoimmune disorders, inflammatory diseases, and cancer. Although IL-10 itself primarily acts on leukocytes and has potent immunosuppressive functions, other family members preferentially target nonimmune compartments, such as tissue epithelial cells, where they elicit innate defense mechanisms to control viral, bacterial, and fungal infections, protect tissue integrity, and promote tissue repair and regeneration. As cytokines are prime drug targets, IL-10 family cytokines provide great opportunities for the treatment of autoimmune diseases, tissue damage, and cancer. Yet no therapy in this space has been approved to date. Here, we summarize the diverse biology of the IL-10 family as it relates to human disease and review past and current strategies and challenges to target IL-10 family cytokines for clinical use.

Interferon lambda 3/4 polymorphisms are associated with AIDS-related Kaposi's sarcoma

BACKGROUND

Kaposi's sarcoma, the most common AIDS-related cancer, represents a major public concern in resource-limited countries. Single nucleotide polymorphisms within the Interferon lambda 3/4 region (IFNL3/4) determine the expression, function of IFNL4, and influence the clinical course of an increasing number of viral infections.

OBJECTIVES

To analyze whether IFNL3/4 variants are associated with susceptibility to AIDS-related Kaposi's sarcoma among MSM enrolled in the Swiss HIV Cohort Study (SHCS).

METHODS

The risk of developing Kaposi's sarcoma according to the carriage of IFNL3/4 SNPs rs8099917 and rs12980275 and their haplotypic combinations was assessed by using cumulative incidence curves and Cox regression models, accounting for relevant covariables.

RESULTS

Kaposi's sarcoma was diagnosed in 221 of 2558 MSM Caucasian SHCS participants. Both rs12980275 and rs8099917 were associated with an increased risk of Kaposi's sarcoma (cumulative incidence 15 versus 10%, P = 0.01 and 16 versus 10%, P = 0.009, respectively). Diplotypes predicted to produce the active P70 form (cumulative incidence 16 versus 10%, P = 0.01) but not the less active S70 (cumulative incidence 11 versus 10%, P = 0.7) form of IFNL4 were associated with an increased risk of Kaposi's sarcoma, compared with those predicted not to produce IFNL4. The associations remained significant in a multivariate Cox regression model after adjustment for age at infection, combination antiretroviral therapy, median CD4+ T-cell count nadir and CD4+ slopes (hazard ratio 1.42, 95% confidence interval 1.06-1.89, P = 0.02 for IFLN P70 versus no IFNL4).

CONCLUSION

This study reports for the first time an association between IFNL3/4 polymorphisms and susceptibility to AIDS-related Kaposi's sarcoma.

IL-28B rs12979860 polymorphism affect the course of chronic hepatitis and the development of HCC in Egyptian patients with hepatitis C type 4

BACKGROUND

A single nucleotide polymorphism (SNP) in the interleukin 28B (IL28B) gene may alter the trajectory of hepatitis C virus (HCV) chronic infection. Several studies have sought to determine a link between IL28B rs12979860 SNP and the development of HCV-related hepatocellular carcinoma (HCC), but with variable results, and consensus is awaited. We hypothesised that IL28B rs12979860 SNP is linked to HCC in patients with HCV type 4.

METHODS

IL28B genotyping of 300 patients with HCV-related fibrosis (n = 100), cirrhosis (n = 100) and HCC (n = 100) was carried out and the results were analysed to determine the association between the IL28B genotype and clinical outcome.

RESULTS

In IL28B TT genotype carriers, the proportions of moderate/severe fibrosis, advanced cirrhosis (Child B-C) and HCC (50%, 84% and 60.2%, respectively) were higher (p < 0.05) than in CC/CT (4.3%, 46% and 23%, respectively). IL-28B SNP was linked significantly (p < 0.05) with cirrhosis progression and HCC advanced stages. Moreover, HCC advanced Child, Okuda and CLIP stages were associated with T allele carriage (73.9%, 82.6% and 78.3% vs. 44.2%, 50.6% and 46.8% in CC/CT). The percentage of large tumour size (> 3cm) increased (p = 0.028) in TT genotype carriers (81.8% vs.52.6% in CC/CT).

CONCLUSION

IL-28B rs12979860 TT genotype is more prevalent in patients with advanced fibrosis, cirrhosis and HCC stages. Thus, it seems to be associated with poor outcomes in chronic HCV patients and to augment the risk of developing HCC.

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.

Synergy with interferon-lambda 3 and sorafenib suppresses hepatocellular carcinoma proliferation

Hepatocellular carcinoma (HCC) is a common and fatal malignancy of the liver. Sorafenib is a small molecule multikinase inhibitor that acts against different cancer cell lines and is used for the treatment of HCC. However, some advanced HCC patients fail to respond to sorafenib, and those who do lack a meaningful clinical benefit. Interferon-lambda 3 (IFN-λ3) is a type III interferon with antiviral, antiproliferative, and immunomodulatory functions. Here, we evaluated the use of IFN-λ3 as an adjuvant treatment with sorafenib in HCC. In the present study, CCK-8 and colony formation assay results showed that treatment with a combination of IFN-λ3 and sorafenib suppresses the viability of HepG2 and SMMC7721 liver cancer cell lines more than treatment with either alone. In addition, flow cytometry results confirmed that treatment with a combination of IFN-λ3 and sorafenib promotes the loss of mitochondrial membrane potential and induces the production of ROS more than treatment with either alone. Furthermore, using a subcutaneous SMMC7721 tumor model, treatment with a combination of IFN-λ3 and sorafenib significantly reduced the tumor growth/volume and induced apoptosis compared to treatment with sorafenib alone. These results show that combined treatment with IFN-λ3 and sorafenib facilitates a synergistic effect on suppressing HCC cancer growth and promoting cell apoptosis in vitro and in vivo. Thus, IFN-λ3 in combination with sorafenib might prove to be a useful adjunctive strategy for the clinical treatment of HCC.

Targeting IFN-λ: therapeutic implications

INTRODUCTION

Type-III interferons (IFN-λ), the most recently discovered family of IFNs, shares common features with other family members, but also has many distinctive activities. IFN-λ uniquely has a different receptor complex, and a more focused pattern of tissue expression and signaling effects, from other classes of IFNs. Multiple genome-wide association studies (GWAS) and subsequent validation reports suggest a pivotal role for polymorphisms near the IFNL3 gene in hepatitis C clearance and control, as also for several other epithelial cell tropic viruses. Apart from its antiviral activity, IFN-λ possesses anti-tumor, immune-inflammatory and homeostatic functions. The overlapping effects of IFN-λ with type I IFN, with a restricted tissue expression pattern renders IFN-λ an attractive therapeutic target for viral infection, cancer and autoimmune diseases, with limited side effects. Areas covered: This review will summarize the current and future therapeutic opportunities offered by this most recently discovered family of interferons. Expert opinion: Our knowledge on IFN-λ is rapidly expanding. Though there are many remaining questions and challenges that require elucidation, the unique characteristics of IFN-λ increases enthusiasm that multiple therapeutic options will emerge.

Crystal Structure of a Complex of the Intracellular Domain of Interferon λ Receptor 1 (IFNLR1) and the FERM/SH2 Domains of Human JAK1

The crystal structure of a construct consisting of the FERM and SH2-like domains of the human Janus kinase 1 (JAK1) bound to a fragment of the intracellular domain of the interferon-λ receptor 1 (IFNLR1) has been determined at the nominal resolution of 2.1Å. In this structure, the receptor peptide forms an 85-Å-long extended chain, in which both the previously identified box1 and box2 regions bind simultaneously to the FERM and SH2-like domains of JAK1. Both domains of JAK1 are generally well ordered, with regions not seen in the crystal structure limited to loops located away from the receptor-binding regions. The structure provides a much more complete and accurate picture of the interactions between JAK1 and IFNLR1 than those given in earlier reports, illuminating the molecular basis of the JAK-cytokine receptor association. A glutamate residue adjacent to the box2 region in IFNLR1 mimics the mode of binding of a phosphotyrosine in classical SH2 domains. It was shown here that a deletion of residues within the box1 region of the receptor abolishes stable interactions with JAK1, although it was previously shown that box2 alone is sufficient to stabilize a similar complex of the interferon-α receptor and TYK2.

The role of IL-29 in immunity and cancer

Interleukin-29 (IL-29) is a new member of the recently discovered interferon λ (IFNλ) family. It is produced predominantly by maturing dendritic cells and macrophages. It has been implicated in numerous immunological responses and has shown antiviral activity similar to the Type I interferons, although its target cell population is more limited than the Type I interferons. In recent years, the role of IL-29 in the pathogenesis of various cancers has also been extensively studied. In this review, we will discuss the recent advances of IL-29 in immunological processes and the pathogenesis of various cancer.

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.

IFN-λ cancer immunotherapy: new kid on the block

Interferon-lambda (IFN-λ) is a new IFN type, related to IFN-α, that is commonly used in the clinic. However, significant side effects accompanying IFN-α treatment limit enthusiasm for IFN-α. In this review, we discuss the current landscape of IFN-α use in oncology and describe the biologic characteristics of IFN-λ. IFN-λ offers unique advantages, including a more tumor cell selective targeting, lower off-target binding and an ability to generate both innate and adaptive immune responses. IFN-λ has also demonstrated therapeutic benefit in murine cancer models. IFN-λ may be used in clinic as a single agent or in combination with other immunotherapy agents, such as immune checkpoint inhibitors. Further clinical trials will be needed to fully elucidate the potential of this novel agent in oncology.

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.

Clinical significance of serum interleukin-29, interleukin-32, and tumor necrosis factor alpha levels in patients with gastric cancer

Many studies suggested that cytokines interleukin (IL)-29, IL-32, and tumor necrosis factor alpha (TNF-α) are implicated in the pathogenesis of malignancies. The purpose of this study was to determine the clinical significance of the serum levels of IL-29, IL-32, and TNF-α in gastric cancer (GC) patients. Fifty-eight GC patients and 20 age- and sex-matched healthy controls were enrolled into this study. The median age at diagnosis was 59.5 years (range 32-82 years). Tumor localization of the majority of the patients was antrum (n = 42, 72.4 %), and tumor histopathology of the majority of the patients was diffuse (n = 43, 74.1 %). The majority of the patients had stage IV disease (n = 41, 70.7 %). Thirty-six (62.1 %) patients had lymph node involvement. The median follow-up time was 66 months (range 1 to 97.2 months). The baseline serum IL-29 concentrations were not different between patients and controls (p = 0.627). The baseline serum IL-32 and TNF-α concentrations of the GC patients were significantly higher (for IL-32, p = 0.014; for TNF-α, p = 0.001). Gender, localization, histopathology, tumor, and lymph node involvement were not found to be correlated with serum IL-29, IL-32, and TNF-α concentrations (p > 0.05). Patients without metastasis (p = 0.01) and patients who responded to chemotherapy (p = 0.04) had higher serum IL-29 concentrations. Patients older than 60 years had higher serum IL-32 (p = 0.002). Serum IL-29, IL-32, and TNF-α levels were not associated with outcome (p = 0.30, p = 0.51, and p = 0.41, respectively). In conclusion, serum levels of IL-32 and TNF-α may be diagnostic markers, and serum IL-29 levels may be associated with good prognosis in patients with GC.

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.

IFN-λ resolves inflammation via suppression of neutrophil infiltration and IL-1β production

Blazek et al. demonstrate that treatment with IL-28A reduces inflammation in collagen-induced arthritis by restricting the recruitment of IL-1β⁺ neutrophils.

The most studied biological role of type III interferons (IFNs) has so far been their antiviral activity, but their role in autoimmune and inflammatory diseases remains largely unexplored. Here, we show that treatment with IFN-λ2/IL-28A completely halts and reverses the development of collagen-induced arthritis (CIA) and discover cellular and molecular mechanisms of IL-28A antiinflammatory function. We demonstrate that treatment with IL-28A dramatically reduces numbers of proinflammatory IL-17–producing Th17 and γδ T cells in the joints and inguinal lymph nodes, without affecting T cell proliferative responses or levels of anticollagen antibodies. IL-28A exerts its antiinflammatory effect by restricting recruitment of IL-1b–expressing neutrophils, which are important for amplification of inflammation. We identify neutrophils as cells expressing high levels of IFN-λ receptor 1 (IFNLR1)–IL-28 receptor α (IL28RA) and targeted by IL-28A. Our data highlight neutrophils as contributors to the pathogenesis of autoimmune arthritis and present IFN-λs or agonists of IFNLR1–IL28RA as putative new therapeutics for neutrophil-driven inflammation.

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.

GEP-NETs update: Biotherapy for neuroendocrine tumours

Neuroendocrine tumours (NETs) represent a less frequent and heterogeneous group of tumours, which has experienced, in recent years, a significant increase in effective therapeutic possibilities overcoming the disappointing results from chemotherapy. Initial improvements in treatment strategies came from somatostatin analogues (SSAs) that have widely demonstrated a significant improvement in symptomatic relief and tumour control growth by a complex mechanism of action over cell survival, angiogenesis and immunomodulation. Recent investigations have pointed out novel SSAs with a wider binding profile (pasireotide), chimeric molecules against somatostatin receptors and dopamine receptors and the combination with targeted agents, such as mTOR inhibitors or antiangiogenic agents. Immunotherapy is the second cornerstone in NET treatment and has been represented with interferon alpha for a long time, with a demonstrated activity on tumour and clinical response. Its less manageable adverse events have limited its usage. However, different checkpoints in immune system regulation have been effectively targeted in different solid tumours, and novel approaches are currently arising in NETs. In conclusion, biotherapy remains an active treatment strategy for initial approach in patients with NETs. Further investigation on patients' selection, molecular profiles, treatment sequence or combination and optimisation of current and novel biotherapy agents is required.

Type III interferons (IFNs): Emerging Master Regulators of Immunity

Lambda interferons (IFN-λs), type III interferons or interleukins 28 and 29 are the latest addition to the class II cytokine family. They share low homology with the interferon (IFN) and IL-10 cytokine families, yet they exhibit common and unique activities, the full spectrum of which still remains incompletely understood. Although initially described for their antiviral functions, it is now appreciated that IFN-λs also mediate diverse antitumor and immune-modulatory effects, and are key determinants of innate immunity at mucosal sites such as the gastrointestinal and respiratory tracks. Here, we are reviewing the biological functions of IFN-λs, the mechanisms controlling their expression, their downstream effects and their role in the maintenance of homeostasis and disease. We are also exploring the potential application of IFN-λs as novel therapeutics.

Suppression of hepatocellular carcinoma proliferation and hepatitis B surface antigen secretion with interferon-λ1 or PEG-interferon-λ1

Hepatocellular carcinoma (HCC) is a common cancer associated with chronic hepatitis B virus (HBV) infection. Conventional interferon-α (IFN-α) and pegylated IFNs (PEG-IFNs) approved for chronic HBV infection treatment can reduce the risk of HCC but are not suitable for the majority of patients and cause significant side effects. IFN-λ1 is a type III IFN with antiviral, antiproliferative, and immunomodulatory functions similar to type I IFNs but with fewer side effects. However, the tolerability and antitumor activity of PEG-IFN-λ1 in HCC xenograft mice are unknown. In vitro IFN-λ1 treatment of Hep3B and Huh7 human hepatoma cell lines increased MHC class I expression, activated JAK-STAT signaling pathways, induced IFN-stimulated gene expression, and inhibited hepatitis B surface antigen (HBsAg) expression. IFN-λ1 treatment also caused 23.2 and 19.9% growth inhibition of Hep3B and Huh7 cells, respectively, and promoted cellular apoptosis. PEG-IFN-λ1, but not IFN-λ1 treatment, significantly suppressed tumor growth (P=0.002) and induced tumor cell apoptosis in a Hep3B cell xenograft mouse model without significant weight loss or toxicity. PEG-IFN-λ1 also significantly inhibited (P=0.000) serum HBsAg secretion from Hep3B xenograft tumors in vivo. Thus, PEG-IFN-λ1 can suppress Hep3B xenograft tumor growth and inhibit HBsAg production and may be a potential treatment for HBV-related HCC.

Interleukin-28A promotes IFN-γ production by peripheral blood mononuclear cells from patients with Behçet's disease

Behçet's disease (BD) is an autoimmune disease of unknown etiology. Interleukin-28A (IL-28A) promotes immune responses and may participate in the pathogenesis of autoimmune diseases. To examine the role of IL-28A in the pathogenesis of BD, we measured the expression of IFN-γ and IL-17 by IL-28A-stimulated peripheral blood mononuclear cells (PBMCs) from 19 patients with BD and 16 healthy individuals. We found that IFN-γ and IL-17 were undetectable in the sera from BD patients and control subjects. The mRNA expression and protein production of IFN-γ by IL-28A-stimulated PBMCs from BD patients were significantly increased compared to healthy individuals. No significant difference was observed in the mRNA expression and protein production of IL-17 by IL-28A-stimulated PBMCs between BD patients and normal individuals.

Functional characterization of canine interferon-lambda

In this study, we provide the first comprehensive annotation of canine interferon-λ (CaIFN-λ, type III IFN). Phylogenetic analysis based on genomic sequences indicated that CaIFN-λ is located in the same branch with Swine IFN-λ1 (SwIFN-λ), Bat IFN-λ1 (BaIFN-λ), and human IFN-λ1 (HuIFN-λ1). CaIFN-λ was cloned, expressed in Escherichia coli, and purified to further investigate the biological activity in vitro. The recombinant CaIFN-λ (rCaIFN-λ) displayed potent antiviral activity on both homologous and heterologous animal cells in terms of inhibiting the replication of the New Jersey serotype of vesicular stomatitis virus (VSV), canine parvovirus, and influenza virus A/WSN/33 (H1N1), respectively. In addition, we also found that rCaIFN-λ exhibits a significant antiproliferative response against A72 canine tumor cells and MDCK cells in a dose-dependent manner. Furthermore, CaIFN-λ activated the JAK-STAT signaling pathway. To evaluate the expression of CaIFN-λ induced by virus and the expression of IFN-stimulated genes (ISGs) induced by rCaIFN-λ in the MDCK cells, we measured the relative mRNA level of CaIFN-λ and ISGs (ISG15, Mx1, and 2'5'-OAS) by quantitative real-time PCR and found that the mRNA level of CaIFN-λ and the ISGs significantly increased after treating the MDCK cells with viruses and rCaIFN-λ protein, respectively. Finally, to evaluate the binding activity of rCaIFN-λ to its receptor, we expressed the extracellular domain of the canine IFN-λ receptor 1 (CaIFN-λR1-EC) and determined the binding activity via ELISA. Our results demonstrated that rCaIFN-λ bound tightly to recombinant CaIFN-λR1-EC (rCaIFN-λR1-EC).

IL28B minor allele is associated with a younger age of onset of hepatocellular carcinoma in patients with chronic hepatitis C virus infection

BACKGROUND

IL28B polymorphisms were shown to be associated with a response to peg-interferon-based treatment in chronic hepatitis C (CHC) and spontaneous clearance. However, little is known about how this polymorphism affects the course of CHC, including the development of hepatocellular carcinoma (HCC). We evaluated the influence of IL28B polymorphisms on hepatocarcinogenesis in CHC patients.

METHODS

We genotyped the rs8099917 single-nucleotide polymorphism in 351 hepatitis C-associated HCC patients without history of IFN-based treatment, and correlated the age at onset of HCC in patients with each genotype.

RESULTS

Frequencies of TT, TG, and GG genotypes were 74.3 % (261/351), 24.8 % (87/351), and 0.9 % (3/351), respectively. The mean ages at onset of HCC for TT, TG, and GG genotypes were 69.9, 67.5 and 66.8, respectively. In multivariate analysis, IL28B minor allele (TG and GG genotypes) was an independent risk factor for younger age at onset of HCC (P = 0.02) in males (P < 0.001) with higher body mass index (BMI; P = 0.009). The IL28B minor allele was also associated with a lower probability of having aspartate aminotransferase-to-platelet ratio index (APRI) >1.5 (minor vs. major, 46.7 vs. 58.6 %; P = 0.01), lower AST (69.1 vs. 77.7 IU/L, P = 0.02), lower ALT (67.8 vs. 80.9 IU/L, P = 0.002), higher platelet count (12.8 vs. 11.2 × 10(4)/μL, P = 0.002), and higher prothrombin time (79.3 vs. 75.4 %, P = 0.002).

CONCLUSIONS

The IL28B minor allele was associated with lower inflammatory activity and less progressed fibrosis of the liver; however, it constituted a risk factor for younger-age onset of HCC in CHC patients.

Interferon-λ1 linked to a stabilized dimer of Fab potently enhances both antitumor and antiviral activities in targeted cells

The type III interferons (IFNs), comprising IFN-λ1, IFN-λ2, and IFN-λ3, behave similarly to IFN-α in eliciting antiviral, antitumor, and immune-modulating activities. Due to their more restricted cellular targets, IFN-λs are attractive as potential alternatives to existing therapeutic regimens based on IFN-αs. We have applied the DOCK-AND-LOCK™ method to improve the anti-proliferative potency of IFN-λ1 up to 1,000-fold in targeted cancer cell lines by tethering stabilized Fab dimers, derived from hRS7 (humanized anti-Trop-2), hMN-15 (humanized anti-CEACAM6), hL243 (humanized anti-HLA-DR), and c225 (chimeric anti-EGFR), to IFN-λ1 site-specifically, resulting in novel immunocytokines designated (E1)-λ1, (15)-λ1, (C2)-λ1, and (c225)-λ1, respectively. Targeted delivery of IFN-λ1 via (15)-λ1 or (c225)-λ1 to respective antigen-expressing cells also significantly increased antiviral activity when compared with non-targeting (C2)-λ1, as demonstrated in human lung adenocarcinoma cell line A549 by (15)-λ1 against encephalomyocarditis virus (EC₅₀ = 22.2 pM versus 223 pM), and in human hepatocarcinoma cell line Huh-7 by (c225)-λ1 against hepatitis C virus (EC₅₀ = 0.56 pM versus 91.2 pM). These promising results, which are attributed to better localization and stronger binding of IFN-λ1 to antibody-targeted cells, together with the favorable pharmacokinetic profile of (E1)-λ1 in mice (T_1/2 = 8.6 h), support further investigation of selective prototypes as potential antiviral and antitumor therapeutic agents.

Modulation of PAR expression and tryptic enzyme induced IL-4 production in mast cells by IL-29

Interleukin (IL)-29 is a relatively newly discovered cytokine, which has been shown to be actively involved in the pathogenesis of allergic inflammation. However, little is known of the effects of IL-29 on protease activated receptor (PAR) expression and potential mechanisms of cytokine production in mast cells. In the present study, we examined potential influence of IL-29 on PAR expression and cytokine production in P815 and bone marrow derived mast cells (BMMCs) by using flow cytometry analysis, quantitative real time PCR, and ELISA techniques. The results showed that IL-29 downregulated the expression of PAR-1 by up to 56.2%, but had little influence on the expression of PAR-2, PAR-3 and PAR-4. IL-29 also induced downregulation of expression of PAR-1 mRNA. However, when mast cells were pre-incubated with IL-29, thrombin-, trypsin- and tryptase-induced expression of PAR-2, PAR-3 and PAR-4 was upregulated, respectively. IL-29 provoked approximately up to 1.9-fold increase in IL-4 release when mast cells was challenged with IL-29. Administration of IL-29 blocking antibody, AG490 or LY294002 abolished IL-29-induced IL-4 release from P815 cells. It was found that IL-29 diminished trypsin- and tryptase-induced IL-4 release from P815 cells following 16 h incubation. In conclusion, IL-29 can regulate expression of PARs and tryptase- and trypsin-induced IL-4 production in mast cells, through which participates in the mast cell related inflammation.

The novel somatostatin receptor 2/dopamine type 2 receptor chimeric compound BIM-23A758 decreases the viability of human GOT1 midgut carcinoid cells

The majority of neuroendocrine tumors (NETs) of the gastroenteropancreatic system coexpress somatostatin receptors (SSTRs) and dopamine type 2 receptors (D2R), thus providing a rationale for the use of novel SSTR2/D2R chimeric compounds in NET disease. Here we investigate the antitumor potential of the SSTR2/D2R chimeric compounds BIM-23A760 and BIM-23A758 in comparison to the selective SSTR2 agonist BIM-23023 and the selective D2R agonist BIM-53097 on human NET cell lines of heterogeneous origin. While having only minor effects on human pancreatic and bronchus carcinoid cells (BON1 and NCI-H727), BIM-23A758 induced significant antitumor effects in human midgut carcinoid cells (GOT1). These effects involved apoptosis induction as well as inhibition of mitogen-activated protein kinase and Akt signaling. Consistent with their antitumor response to BIM-23A758, GOT1 cells showed relatively high expression levels of SSTR2 and D2R mRNA. In particular, GOT1 cells highly express the short transcript variant of D2R. In contrast to BIM-23A758, the SSTR2/D2R chimeric compound BIM-23A760 as well as the individual SSTR2 and D2R agonistic compounds BIM-23023 and BIM-53097 induced no or only minor antitumor responses in the examined NET cell lines. Taken together, our findings suggest that the novel SSTR2/D2R chimeric compound BIM-23A758 might be a promising substance for the treatment of NETs highly expressing SSTR2 and D2R. In particular, a sufficient expression of the short transcript variant of DR2 might play a pivotal role for effective treatment.

Potential anti-tumor effect of IFN-λ2 (IL-28A) against human lung cancer cells

Interferon (IFN)-λs (IL-28A/IL-28B/IL-29) classified as type III IFNs, are the latest members identified of the interferon family. As with type I IFNs such as IFN-α, type III IFNs share antiviral and antitumor activity and may have fewer side effects due to a more selective receptor distribution. Therefore, type III IFNs may be clinically useful for human viral and malignant diseases. Here we demonstrate the potential anti-tumor effect of IFN-λ2 (IL-28A) against human lung cancer cells. All lung cancer cell lines that we examined expressed both IFN-λ receptors (IL-28R1 and IL-10R2). Lung cancer cells with epidermal growth factor receptor (EGFR) mutations were more sensitive to IFN-λ2 treatment compared with cells with KRAS mutations. HCC827 cells with an EGFR mutation treated with IFN-λ2 underwent growth suppression and apoptotic cell death by STAT1 phosphorylation. Administration of neutralizing antibodies to IFN-λ inhibited caspase-3/7 activity induced by IFN-λ2. Finally, in vivo luminescent imaging also demonstrated the anti-tumor effect of IFN-λ2 in a cancer cell transplant animal model. Taken together, IFN-λ2 would be a new therapeutic agent for clinical lung cancers with EGFR mutations.

Interferon-λs: special immunomodulatory agents and potential therapeutic targets

Interferon (IFN)-λs are a new addition to the old IFN family and share many similarities, such as antiviral and antiproliferative characteristics, with type I IFNs. IFN-λs also exhibit unique characteristics in immunomodulation. Accumulating studies have indicated the interactions between IFN-λs and immune cells, which lead to the regulation of the latter. IFN-λs can influence dendritic cells (DCs) and their product, IFN-λs-DCs, can then regulate the function of T cells. On the other hand, IFN-λs can also directly affect T cells through inhibition of the T helper 2 cell (Th2) responses. IFN-λs have varying immunomodulatory functions under different physiological conditions or in different organs and can inhibit tumor growth via regulation of the immune system. Diseases associated with IFN-λs include asthma, allergy, and systemic lupus erythematosus. In this review, we summarize the current knowledge of the biology of IFN-λs and their immunomodulatory function in relevant human diseases.

Interaction of IFNλR1 with TRAF6 regulates NF-κB activation and IFNλR1 stability

IFNλR1 is a member of the class II cytokine receptor family, and it associates with IL-10R2 to form a functional receptor complex, IFNλR. This receptor complex transduces signals from IFNλs (IFNλ1, IFNλ2, and IFNλ3), promoting antiviral and antiproliferative activities similar to those of type I IFNs. In an effort to further understand signal transduction through IFNλR1, we used bioinformatics analysis and identified a tumor necrosis factor receptor-associated factor 6 (TRAF6)-binding motif in the intracellular domain of IFNλR1. In subsequent immunoprecipitation and GST pull-down assays, IFNλR1 was shown to immunoprecipitate with TRAF6 and was pulled down by GST-TRAF6. Endogenous IFNλR1 and TRAF-6 interaction implies that these proteins really interact in the cells. This interaction was abrogated upon mutation of the TRAF6-binding motif in IFNλR1. Furthermore, the interaction between IFNλR1 and TRAF6 inhibited TRAF6-induced NF-κB activation, likely due to a reduction in TRAF6 autoubiquitination. Moreover, co-expression of IFNλR1 with TRAF6 significantly increased the stability of IFNλR1, thereby prolonging its half-life and enhancing its steady-state level in cultured cells.

Analysis of genetic variants of class II cytokine and their receptor genes in psoriasis patients of two ethnic groups from the Volga-Ural region of Russia

BACKGROUND

The molecular basis of pathogenesis of psoriasis remains unclear, but one unifying hypothesis of disease aetiology is the cytokine network model. The class II cytokines (CF2) and their receptors (CRF2) are all involved in the inflammatory processes and single nucleotide polymorphisms (SNPs) in respective genes have been associated with psoriasis in a previous study of the Estonian population.

OBJECTIVE

We performed a replication study of 47 SNPs in CF2 and CRF2 genes in independent cohorts of psoriasis patients of two ethnic groups (Russians and Bashkirs) from the Volga-Ural region of Russia.

METHODS

DNA was obtained from 395 psoriasis patients of two ethnic groups from the Volga-Ural region of Russia and 476 ethnically matched controls. 47 SNPs in the loci of the genes encoding Class II cytokines and their receptors were selected by SNPbrowser version 3.5. Genotyping was performed using the SNPlex™ (Applied Biosystems) platform.

RESULTS

The genetic variant rs30461 previously associated in original case-control study in Estonians, was also associated in Russians (corrected P-value (Pc=0.008, OR=0.44), but did not reach statistical significance in the Bashkir population. Additionally, the haplotype analysis provided that CC haplotype formed by the SNPs rs30461 and rs955155 had a protective effect in Russians (Pc=0.0024, OR=0.44), supporting the involvement of this locus in the protection against psoriasis. Combined meta-analysis of three populations, including 943 psoriasis patients and 812 healthy controls, showed that the IL29 rs30461 C-allele was not associated with decreased risk of psoriasis (P=0.165, OR=0.68). Moreover, stratification of studies by ethnicity revealed a significant association in the European cohort (P=9.506E-006, OR=0.53).

CONCLUSION

Therefore, there is no overall evidence of association between psoriasis and SNP rs30461 of the IL29 gene, but there is some evidence to suggest that an association exists in Europeans. However, this current concept should be considered as preliminary and the results need to be confirmed in future independent studies.

Type III IFNs are produced by and stimulate human plasmacytoid dendritic cells

Plasmacytoid dendritic cells (pDC) are rare cells found in peripheral blood and lymphoid tissues. pDC are considered to be "professional" type I IFN-producing cells and produce 10- to 100-fold more IFN-α than other cell types in response to enveloped viruses or synthetic TLR7 and TLR9 agonists. In this study, purified pDC were found to express high levels of IFN-λ receptor mRNA, as well as cell-surface IFN-λ receptor. We have developed intracellular flow cytometry assays using Abs to IFN-λ1/3 or -λ2 to assess the expression of IFN-λ proteins by pDC. We observed that a subset of human pDC expresses only intracellular IFN-α, whereas another subset produces both IFN-α and IFN-λ after stimulation with virus or the TLR9 agonist, CpG A; the cells that coexpressed IFN-α and IFN-λ were the cells with the highest levels of IFN-α expression. Ab cross-linking of CD4 or CD303 molecules on pDC inhibited both HSV-induced IFN-λ and IFN-α production. Like the production of IFN-α, the HSV-induced IFN-λ production in pDC was mediated through TLR9 and independent of virus replication. Exogenous IFN-λ treatment of pDC resulted in increased virus-induced expression of both IFN-α and IFN-λ. In addition, both exogenous IFN-λ and -α inhibited dexamethasone-induced apoptosis of pDC. We conclude that pDC are major producers of IFN-λ1 and -λ2 in response to viral stimulation and also express functional receptors for this cytokine. Thus, IFN-λ can serve as an autocrine signal to strengthen the antiviral response of pDC by increasing IFN-α and IFN-λ production, resulting in prolonged pDC survival.

Identification of pro-inflammatory cytokines associated with muscle invasive bladder cancer; the roles of IL-5, IL-20, and IL-28A

We used gene expression profiling to identify inflammatory cytokines that correlate with bladder cancer development. Gene expression profiles of the tissue samples were investigated using cDNA microarrays that contained 103 non-muscle invasive bladder cancers (NMIBC), 62 muscle invasive bladder cancers (MIBC), 58 samples of histologically normal-looking surrounding tissues, and 10 normal, healthy subjects who served as the control cohort for comparison. We grouped the data-sets according to biological characterizations and focused on immune response genes with at least 2-fold differential expression in MIBC vs. controls. The experimental data-set identified 36 immune-related genes that were significantly altered in MIBC samples. In addition, 10 genes were up-regulated and 26 genes were down-regulated in MIBC samples compared with the normal tissues. Among the 10 up-regulated molecules examined, the capacity for both wound-healing migration and invasion was enhanced in response to IL-5, IL-20, and IL-28A in bladder cancer cell lines (253J and EJ cells), compared with untreated cells. The expression levels of IL-5, IL-20, and IL-28A were increased in patients with MIBC. All 3 cytokines and their receptors were produced in bladder cancer cell lines, as determined by real-time PCR, immunoblot analysis and confocal immunofluorescence. Up-regulation of MMP-2 and MMP-9 was found after IL-5, IL-20, and IL-28A stimulation in both cell types. Moreover, an EMSA assay showed that treatment with IL-5, IL-20, and IL-28A induced activation of the transcription factors NF-κB and AP-1 that regulate the MMP-9 promoter. Finally, activation of MAPK and Jak-Stat signaling was observed after the addition of IL-5, IL-20, and IL-28A to bladder cancer cells. This study suggests the presence of specific inflammatory cytokine (IL-5, IL-20, and IL-28A)-mediated association in bladder cancer development. All 3 cytokines may be important new molecular targets for the modulation of migration and invasion in bladder cancer.