IFNalpha and IFNlambda differ in their antiproliferative effects and duration of JAK/STAT signaling activity

Antitumor activity of type III interferon alone or in combination with type I interferon against human non-small cell lung cancer

The antitumor activities of type III interferon (IFN) (interleukin [IL]-28 and IL-29) and the combination of type III IFN and type I IFN (IFN-α) were evaluated using human non-small cell lung cancer (NSCLC). The expression of type III and type I receptor complexes was detected in NSCLC lines. IL-29 significantly inhibited the in vitro growth of a wide range of NSCLC lines in a dose-dependent fashion. To a lesser degree, IL-28A also displayed growth inhibitory activity. Antitumor activity of type III IFN is associated with cell cycle arrest at the G1 phase and apoptosis. IL-29 upregulated cyclin-dependent kinase inhibitor p21Waf1/Cip1 in cells sensitive, but not insensitive, to antiproliferative activity, and knockdown of p21 with small interfering RNA largely attenuated the antiproliferative effect. Intratumoral and systemic administration of IL-29 inhibited OBA-LK1 and LK-1, but not A549, tumor growth in severe combined immunodeficiency mice. Immunohistochemical analyses demonstrated marked upregulated p21 and downregulated Ki-67 expression in tumors treated with IL-29. The interferon combination of IL-29 and IFN-α displayed a more effective antiproliferative effect and a more intense p21 expression than each reagent alone in vitro. Furthermore, interferon combination therapy suppressed in vivo NSCLC growth more effectively than interferon monotherapy. These findings demonstrate that type III IFN can mediate direct antitumor activities via increased p21 expression and induction of apoptosis and cooperate with type I IFN to elicit more efficient direct antitumor activities, and suggest the possibility that type III IFN might improve the efficacy and reduce the side-effects of type I IFN cancer therapy.

A possible anticancer agent, type III interferon, activates cell death pathways and produces antitumor effects

Recently identified interleukin-28 and -29 belong to a novel type III interferon (IFN) family, which could have distinct biological properties from type I and II IFNs. Type I IFNs, IFN-α/β, have been clinically applied for treating a certain kind of malignancies for over 30 years, but a wide range of the adverse effects hampered the further clinical applications. Type III IFNs, IFN-λs, have similar signaling pathways as IFN-α/β and inhibits proliferation of tumor cells through cell cycle arrest or apoptosis. Restricted patterns of type III IFN receptor expression in contrast to ubiquitously expressed IFN-α/β receptors suggest that type III IFNs have limited cytotoxicity to normal cells and can be a possible anticancer agent. In this paper, we summarize the current knowledge on the IFN-λs-mediated tumor cell death and discuss the functional difference between type I and III IFNs.

IL28B genotype effects during early treatment with peginterferon and ribavirin in difficult-to-treat hepatitis C virus infection

BACKGROUND

Mathematical models of hepatitis C virus (HCV) during therapy may elucidate mechanisms of action for antiviral therapy. In genome-wide association studies, IL28B gene polymorphisms are highly predictive of therapeutic clearance of HCV.

METHODS

We collected sera from 20 chronically infected HCV participants at 13 points during the first 28 days of therapy. We assessed the presence of the C allele at single-nucleotide polymorphism rs12979860 using the ABI TaqMan allelic discrimination kit. We estimated dynamic parameters from the entire population using the Neumann model for HCV infection. Statistical methods for repeated nonlinear measures compared model parameters by established predictors of response.

RESULTS

The frequencies of IL28B genotypes were 6 (C/C), 11 (C/T), and 3 (T/T). The mean log decline in HCV RNA from 0 to 48 hours was more rapid among C/C genotype participants compared with C/T or T/T genotype participants (1.4 vs 0.7; P = .07), and from 2 days to 14 days (1.6 vs 0.7; P = .04). In the multivariate model, the C/C genotype predicted a steeper second-phase decline when adjusted for race (P = .01).

CONCLUSIONS

The presence of the C/C genotype at IL28B rs12979860 exerts its antiviral effect by increasing the infected hepatocyte death rate. This suggests that an immune-mediated mechanism is responsible.

Antiviral activity of type I and type III interferons against porcine reproductive and respiratory syndrome virus (PRRSV)

The newly identified type III interferons (IFNs), also known as IFN-λ1/IL-29, IFN-λ2/IL-28A and IFN-λ3/IL-28B, like type I IFNs, have antiviral activity against a broad spectrum of viruses. We therefore examined whether type III IFNs, as well as type I IFNs, has the ability to inhibit porcine reproductive and respiratory syndrome virus (PRRSV) replication in MARC-145 cells. We found that replication of PRRSV in MARC-145 cells was significantly reduced following treatment with IFN-λ1, IFN-λ2 and IFN-λ3, respectively, and such inhibition was dose-dependent. However, type III IFNs (IFN-λ1, IFN-λ2 and IFN-λ3) was less effective than type I IFNs (IFN-α and IFN-β) in antiviral activity against PRRSV. Mixture of two types of IFNs could not improve the antiviral activity of each type alone. In addition, all types of IFNs in our study were able to induce the expression of ISG56, 2',5'-OAS and MxA in MARC-145 cells. These data demonstrate that type III IFNs had antiviral activity against PRRSV and may serve as useful antiviral agents against infectious swine diseases.

Antitumor activities of recombinant human interferon (IFN)-λ1 in vitro and in xenograft models in vivo for colon cancer

Interferon (IFN)-λ1, as a newly identified IFN, interacts with the structurally unique IFN-λ1 receptor complex and exhibits antiviral and antiproliferation effects. The major focus of our work was to study the antitumor activities of recombinant human IFN-λ1 (rhIFN-λ1) in vivo and in vitro. The MTT analysis showed that rhIFN-λ1 inhibited the proliferation of HCT116 cells in a dose-dependent manner, but with a less efficacy in HT29 cells than HCT116 cells. IFN-λ1 also activated the STATs and induced apoptosis in both types of cells. In the in vivo study, we found that rhIFN-λ1 suppressed tumor growth in a dose-dependent fashion, with an inhibition rate of 52% of HCT116 (P<0.01) and 56% of HT29 (P<0.01). These results indicate that rhIFN-λ1 could be a new potential IFN reagent for cancer therapy.

Interferon-lambda1 induces peripheral blood mononuclear cell-derived chemokines secretion in patients with systemic lupus erythematosus: its correlation with disease activity

INTRODUCTION

Systemic lupus erythematosus (SLE) is an autoimmune disease involving multiple organ systems. Previous studies have suggested that interferon-lambda 1 (IFN-λ1), a type III interferon, plays an immunomodulatory role. In this study we investigated its role in SLE, including its correlation with disease activity, organ disorder and production of chemokines.

METHODS

We determined levels of IFN-λ1 mRNA in peripheral blood mononuclear cells (PBMC) and serum protein levels in patients with SLE using real-time polymerase chain reaction (real-time PCR) and enzyme-linked immunoassay (ELISA). Further, we detected the concentration of IFN-inducible protein-10 (IP-10), monokine induced by IFN-γ (MIG) and interleukin-8 (IL-8) secreted by PBMC under the stimulation of IFN-λ1 using ELISA.

RESULTS

IFN-λ1 mRNA and serum protein levels were higher in patients with SLE compared with healthy controls. Patients with active disease showed higher IFN-λ1 mRNA and serum protein levels compared with those with inactive disease as well. Serum IFN-λ1 levels were positively correlated with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), anti-dsDNA antibody, C-reactive protein (CRP) and negatively correlated with complement 3. Serum IFN-λ1 levels were higher in SLE patients with renal involvement and arthritis compared with patients without the above-mentioned manifestations. IFN-λ1 with different concentrations displayed different effects on the secretion of the chemokines IP-10, MIG and IL-8.

CONCLUSIONS

These findings indicate that IFN-λ1 is probably involved in the renal disorder and arthritis progression of SLE and associated with disease activity. Moreover, it probably plays an important role in the pathogenesis of SLE by stimulating secretion of the chemokines IP-10, MIG and IL-8. Thus, IFN-λ1 may provide a novel research target for the pathogenesis and therapy of SLE.

IL-28B predicts response to chronic hepatitis C therapy--fine-mapping and replication study in Asian populations

Type I interferon (IFN) is used for the treatment of chronic hepatitis C virus (HCV) infection. Despite advances in antiviral therapy, a large proportion of patients remain infected following current therapies. Through a genome-wide scan, we found two variants (rs8099917 and rs12979860) in the IL-28B locus that affect the outcome of PEG-IFN and ribavirin combination therapy, consistent with recent studies (P = 6.52×10(-8); odds ratio 2.46 and P = 8.63×10(-8), odds ratio 2.40, respectively). Significant associations were also observed in the case of IFN monotherapy for HCV genotypes 1b and 2a. With rs8099917, HCV genotype 1b patients had a significantly lower frequency of the favourable genotype (86.6 %) compared with healthy controls (91.7 %), and HCV genotype 2a patients had an intermediate frequency (89.9 %). Similar results were found for rs12979860. Fine-mapping analysis revealed that rs8099917 had the strongest association with treatment outcome and 14 others, including four novel single nucleotide polymorphisms, had comparable associations. Haplotype analysis revealed that none of the haplotypes showed stronger association than any single marker. Early non-responders who could not achieve 2 log viral decline during the first 12 weeks of treatment had higher odds ratios for these two variants. The favourable allele of rs8099917 is also associated with initial viral decline at 2 and 4 weeks following the start of therapy. Multivariate analysis of PEG-IFN and ribavirin-treated patients showed that rs8099917 genotype, viral load, fibrosis and age were significant predictors of response to therapy. Common variation at the IL-28B locus is predictive of various IFN-based therapies for HCV independent of regimen or HCV genotype.

IL-28B rs12979860 C/T allele distribution in patients with liver cirrhosis: role in the course of chronic viral hepatitis and the development of HCC

BACKGROUND & AIMS

A single nucleotide polymorphism (rs12979860 C/T) 3kb upstream of the interleukin 28B (IL-28B) gene was shown to be associated with hepatitis C clearance. We verified whether this association also translates into a different genotype distribution at the end of the disease trajectory.

METHODS

A RFLP-PCR technique was used to genotype 412 patients with cirrhosis due to hepatitis C (n=199), hepatitis B (n=75), alcohol (n=110), and other causes (n=28), of whom 256 underwent liver transplantation (OLT). Hepatocellular carcinoma (HCC) was demonstrated in the native liver of 85 OLT patients, 52 with viral cirrhosis, and 33 with non-viral cirrhosis respectively. A group of 292 patients (235 HCV and 57 HBV positive) with mild chronic hepatitis and 344 healthy subjects served as controls.

RESULTS

A significant difference (p=0.0005) was observed in IL-28B rs12979860 genotype frequencies between patients with viral cirrhosis (C/C=99, C/T=137, T/T=38) and those with non-viral cirrhosis (C/C=72, C/T=58, T/T=8). Patients with HCV related cirrhosis carried more frequently the T/T genotype in comparison to mild hepatitis C or HBV-related cirrhosis. IL-28B rs12979860 genotype frequencies were C/C=23, C/T=50, T/T=12 among OLT patients with cirrhosis complicated by HCC, and C/C=79, C/T=78, T/T=14 among patients with cirrhosis not complicated by HCC (p<0.005).

CONCLUSIONS

IL-28B rs12979860 C/T polymorphism T allele is more prevalent in patients with viral cirrhosis due to HCV in comparison to other aetiologies and to patients with mild chronic hepatitis C. Among OLT patients, carriage of this allele seems to augment the risk of developing HCC.

Efficient co-expression of bicistronic proteins in mesenchymal stem cells by development and optimization of a multifunctional plasmid

INTRODUCTION

Local synthesis of interferon within B16 tumors mediates anti-tumor effects. Based on reports that stem cells are recruited to tumors, and because systemic administration of interferon causes dose-limiting undesirable side effects, we wanted to improve the anti-tumor effects of interferon while simultaneously minimizing its systemic side effects by employing mesenchymal stem cells (MSCs) as tumor-localized ectopic producers of interferon. Many vectors exist to fulfill this purpose, but their transfection efficiency and resulting expression levels vary considerably.

METHODS

To follow both the recruitment to tumors and the synthesis of interferon by MSCs, we designed a bicistronic vector system that permits fluorescent visualization of vector-transfected and interferon-producing MSCs. We used Mu-IFNαA cDNA as the first cistron and the cherry fluorescent protein cDNA as the second cistron, whose translation requires the internal ribosome entry sequence (IRES) from the encephalomyocarditis virus 5' untranslated region. Observing inconsistent expression of these cistrons in various vectors and cell lines, especially compared with a control plasmid pmaxGFP, we optimized the expression of this bicistronic message by mutating pcDNA3 to facilitate exchange of the promoter and polyadenylation segments controlling both the gene of interest and the eukaryotic antibiotic resistance gene as well as the eukaryotic antibiotic resistance gene itself, and effectively compare the effects of these exchanges, creating plasmid pc3.5.

RESULTS

Murine MSCs stably and ectopically expressing Mu-IFNαA inhibited the establishment of tumors in homogeneic C57/BL6 mice. Mu-IFNαA expressed from the bicistronic message is fully biologically active, but is expressed at only two-thirds of the level observed from a monocistronic message. Cap-dependent translation is threefold more efficient than IRES-driven translation in 293T, B16, and MSC cell lines. Both efficient expression and good transfection efficiency require strong expression of the gene of interest and a chimeric intron. High doses of Mu-IFNαA within tumors inhibited tumor establishment but may not inhibit tumor growth.

CONCLUSIONS

Our modified vector and its derived plasmids will find use in stem cell therapeutics, gene expression, mRNA regulation, and transcription regulation. Local release of Mu-IFNαA within tumors may differently affect tumor establishment and tumor growth.

Interferon-lambda: a new addition to an old family

The discovery and initial description of the interferon-lambda (IFN-lambda) family in early 2003 opened an exciting new chapter in the field of IFN research. There are 3 IFN-lambda genes that encode 3 distinct but highly related proteins denoted IFN-lambda1, -lambda2, and -lambda3. These proteins are also known as interleukin-29 (IL-29), IL-28A, and IL-28B, respectively. Collectively, these 3 cytokines comprise the type III subset of IFNs. They are distinct from both type I and type II IFNs for a number of reasons, including the fact that they signal through a heterodimeric receptor complex that is different from the receptors used by type I or type II IFNs. Although type I IFNs (IFN-alpha/beta) and type III IFNs (IFN-lambda) signal via distinct receptor complexes, they activate the same intracellular signaling pathway and many of the same biological activities, including antiviral activity, in a wide variety of target cells. Consistent with their antiviral activity, expression of the IFN-lambda genes and their corresponding proteins is inducible by infection with many types of viruses. Therefore, expression of the type III IFNs (IFN-lambdas) and their primary biological activity are very similar to the type I IFNs. However, unlike IFN-alpha receptors which are broadly expressed on most cell types, including leukocytes, IFN-lambda receptors are largely restricted to cells of epithelial origin. The potential clinical importance of IFN-lambda as a novel antiviral therapeutic agent is already apparent. In addition, preclinical studies by several groups indicate that IFN-lambda may also be useful as a potential therapeutic agent for other clinical indications, including certain types of cancer.

Interferon-lambda in the immune response to hepatitis B virus and hepatitis C virus

Approximately 500 million people worldwide are chronically infected with the hepatitis B virus (HBV) or hepatitis C virus (HCV), and are therefore at an increased risk for developing fatal liver diseases such as cirrhosis and hepatocellular carcinoma. The intracellular antiviral responses induced by interferon (IFN)-alpha/-beta and/or IFN-gamma play critical roles in the pathogenesis of HBV and HCV infection, and the function of IFN-lambda in the host immune response to these viruses is beginning to be revealed. A better understanding of how IFN-lambda influences HBV or HCV persistence is not only important for understanding the mechanisms of chronic virus infection, but also may lead to new approaches for improved antiviral therapies.

Association of IL28B gene variations with mathematical modeling of viral kinetics in chronic hepatitis C patients with IFN plus ribavirin therapy

Asian patients with chronic hepatitis C (CHC) are known to have better virological responses to pegylated (Peg) IFN-based therapy than Western patients. Although IL28B gene polymorphisms may contribute to this difference, whether favorable hepatitis C virus (HCV) kinetics during treatment plays a role remains unclear. We enrolled 145 consecutive Taiwanese patients with CHC receiving Peg-IFN α-2a plus ribavirin for the study. Blood samples were taken more frequently at defined intervals in the first 3 d. Peg-IFN was administered at week 1. It was then administered weekly in combination with daily ribavirin for 24 or 48 wk. A mathematical model fitted to the observed HCV kinetics was constructed, which could interpret the transient HCV titer elevation after Peg-IFN treatment. The results demonstrated a comparable viral clearance rate (c = 3.45 ± 3.73) (day(-1), mean ± SD) but lower daily viral production rate (P = 10(6)-10(12)) in our patients than those reported previously in Western patients. Of 110 patients with a sustained virological response (SVR), 47 (43%) had a transient elevation of viral titer within 12 h (proportion of 12 h/3 d: 44% in non-SVR vs. 70% in SVR; P = 0.029). Among 91 patients with available rs8099917 data, patients with the TT genotype had an early surge of viral titer after therapy and a higher SVR and viral clearance rate than those with the GT genotype. In conclusion, Taiwanese patients with CHC receiving Peg-IFN plus ribavirin therapy have a lower daily viral production rate than Western patients, and the rs8099917 TT genotype may contribute to the increased viral clearance rate and better virological responses in these patients.

IL28B genomic-based treatment paradigms for patients with chronic hepatitis C infection: the future of personalized HCV therapies

Genome-wide association studies (GWAS) have recently identified host genetic variation to be critical for predicting treatment response and spontaneous clearance in patients infected with hepatitis C virus (HCV). These important new studies are reviewed and their future clinical implications discussed. Single-nucleotide polymorphisms in the region of the IL28B gene on chromosome 19, coding for the interferon (IFN)-λ-3 or IL28B gene, are strongly associated with treatment response to pegylated IFN and ribavirin in patients infected with genotype 1 HCV. The good response variant is associated with a twofold increase in the rate of cure. Allele frequencies differ between ethnic groups, largely explaining the observed differences in response rates between Caucasians, African Americans and Asians. IL28B polymorphism is also strongly associated with spontaneous clearance of HCV. The biological mechanisms responsible for these genetic associations remain unknown and are the focus of ongoing research. Knowledge of a patient's IL28B genotype is likely to aid in clinical decision making with standard of care regimens. Future studies will investigate the possibility of individualizing treatment duration and novel regimens according to IL28B type.

Comparative analysis of the lambda-interferons IL-28A and IL-29 regarding their transcriptome and their antiviral properties against hepatitis C virus

BACKGROUND

Specific differences in signaling and antiviral properties between the different Lambda-interferons, a novel group of interferons composed of IL-28A, IL-28B and IL-29, are currently unknown. This is the first study comparatively investigating the transcriptome and the antiviral properties of the Lambda-interferons IL-28A and IL-29.

METHODOLOGY/PRINCIPAL FINDINGS

Expression studies were performed by microarray analysis, quantitative PCR (qPCR), reporter gene assays and immunoluminometric assays. Signaling was analyzed by Western blot. HCV replication was measured in Huh-7 cells expressing subgenomic HCV replicon. All hepatic cell lines investigated as well as primary hepatocytes expressed both IFN-λ receptor subunits IL-10R2 and IFN-λR1. Both, IL-28A and IL-29 activated STAT1 signaling. As revealed by microarray analysis, similar genes were induced by both cytokines in Huh-7 cells (IL-28A: 117 genes; IL-29: 111 genes), many of them playing a role in antiviral immunity. However, only IL-28A was able to significantly down-regulate gene expression (n = 272 down-regulated genes). Both cytokines significantly decreased HCV replication in Huh-7 cells. In comparison to liver biopsies of patients with non-viral liver disease, liver biopsies of patients with HCV showed significantly increased mRNA expression of IL-28A and IL-29. Moreover, IL-28A serum protein levels were elevated in HCV patients. In a murine model of viral hepatitis, IL-28 expression was significantly increased.

CONCLUSIONS/SIGNIFICANCE

IL-28A and IL-29 are up-regulated in HCV patients and are similarly effective in inducing antiviral genes and inhibiting HCV replication. In contrast to IL-29, IL-28A is a potent gene repressor. Both IFN-λs may have therapeutic potential in the treatment of chronic HCV.

Genetic variation in IL28B: impact on drug development for chronic hepatitis C infection

As more pharmacogenomic insights into diseases and their treatments and toxicities are published each year, the challenge arises to incorporate such insights into clinical practice and drug development. For instance, recent genomic discoveries related to hepatitis C offer a challenge to clinicians, researchers,and health administrators to translate this information into knowledge in order to develop safer and more effective therapeutic strategies for all patients.

IL28B in hepatitis C virus infection: translating pharmacogenomics into clinical practice

Three landmark genome-wide association studies (GWAS) published in 2009 identified the interleukin (IL) 28B gene locus as pivotal to the pathogenesis of hepatitis C virus (HCV) infection. Polymorphisms near the IL28B gene not only predicted treatment-induced and spontaneous recovery from HCV infection, but they also explained, to some extent, the difference in response rates between Caucasians and African Americans to standard therapy with pegylated interferon and ribavirin. The revelation that IL28B, an innate cytokine, plays an essential role in the pathogenesis, outcomes, and treatment responses to HCV infection has triggered a gold rush and an ever increasing number of reports on the subject are being presented at international conferences and in scientific journals. This review will summarize currently available data on the clinical impact of IL28B polymorphisms on HCV infection and the potential mechanisms for its effects. It will conclude with a discussion on how the research observations may translate into clinical practice and drug development.

Structure and function of interleukin-22 and other members of the interleukin-10 family

The IL-10 family of cytokines is comprised of IL-10, IL-19, IL-20, IL-22, IL-24, IL-26, and IFN-lambdas (IL-28A, IL-28B, and IL-29). The IL-10 family members bind to shared class II cytokine receptor chains that associate in various combinations in heterodimeric complexes. Upon interleukin/receptor complex formation, these proteins switch on the Jak/STAT pathway and elicit pleiotropic biological responses whose variety sharply contrasts with their structural similarities. IL-10 family members are involved in several human diseases and health conditions and hence their structural analyses may provide valuable information to design specific therapeutic strategies. In this review, we describe the human interleukin-10 family of cytokines, focusing on their structures and functions, with particular attention given to IL-22 and IL-10. We report on the recently published structures of IL-10 cytokine family members and their complexes with cognate transmembrane and soluble receptors as well as on interleukin physiology and physiopathology.

Interferon-λ in HCV Infection and Therapy

Chronic infection with hepatitis C virus (HCV) is associated with significant liver disease and is therefore an important public health problem. The current standard-of-care therapy for chronic HCV infection consists of a combination of pegylated (PEG) interferon (IFN)-α and ribavirin. Although this therapy effectively generates a sustained viral response in approximately half of treated individuals, it is associated with significant hematological and neurological side effects. A new family of IFN-related proteins (IFN-λ1, 2, and 3; or alternately, IL-29, 28A, 28B, respectively) possesses properties that may make these cytokines superior to PEG-IFN-α for HCV therapy. Genetic studies have also implicated these proteins in both the natural and therapy-induced resolution of HCV infection. This review summarizes the basic aspects of IFN-λ biology, the potential role of these cytokines in HCV infection, and the outlook for their therapeutic application.

Interferon-lambda as a potential therapeutic agent in cancer treatment

The discovery that type I interferon (IFN-alpha/beta) inhibited tumor cell growth was welcomed initially with great excitement as it rapidly became a U.S. Food and Drug Administration-approved drug to treat several forms of cancer. In time, this enthusiasm diminished as severe toxicity associated with IFN-alpha administration, resistance to the therapy, or less than optimal responses became evident in cancer patients, thus restricting its clinical use and reducing its potential as an anticancer drug. The recent discovery of a third type of IFN [IFN-lambda/interleukin (IL)-29/IL-28], which shares the same biological properties of type I IFNs, opens the door for evaluating the therapeutic potential of IFN-lambda as it uses a distinct receptor complex whose expression, unlike type I IFN receptors, is restricted to cells of specific lineage. It is unclear whether the mechanism by which type III IFNs restrict tumor cell proliferation is different or the same from the one utilized by type I IFN. Nevertheless, accumulating evidence as described in this review suggests that, in contrast to IFN-alpha therapy, IFN-lambda therapy could be less toxic and suitable for certain types of malignancies as not all cells are responsive to this cytokine.

Interleukin-28 and interleukin-29: novel regulators of skin biology

The skin forms an essential barrier between the inside of an organism and the environment. In addition to its function in insulation, temperature regulation, and sensation, it protects the body against physical trauma, pathogens, UV radiation, and excessive water loss. Many processes necessary for maintaining the skin integrity, including antimicrobial/antiviral defense, wound healing, and removal of tumors, are regulated by cytokines. Accumulating results lead us to assume that interleukin (IL)-28 and IL-29, 2 novel members of the IL-10-interferon cytokine family, are important regulators of some of these processes. In the skin, IL-28 and IL-29 can be produced by virus-infected cells, maturing dendritic cells (DCs), and regulatory T-cells, and they mainly influence keratinocytes and melanocytes. In keratinocytes, IL-28 and IL-29 induce growth inhibition. Simultaneously, these cytokines increase the cellular synthesis of proteins that directly hinder virus replication and enhance the readiness to present viral antigens to immune cells. Further, IL-28 and IL-29 upregulate expression of viral and microbial sensing cellular receptors, including toll-like receptor (TLR)3, TLR2, and melanoma differentiation associated gene 5, and strengthen the cellular response to these receptors' ligands. Thereby, in the noninfected skin IL-28 and IL-29 enhance the capacity of keratinocytes to react to viral and microbial products and at least indirectly upregulate their inflammatory potential and innate immunity. IL-28 and IL-29 can act synergistically with other mediators secreted during DC maturation (eg, IL-20). In summary, IL-28/IL-29 may play an important role in the skin in the clearance of viral and microbial infections and in the removal of tumors.

Amino acid substitution in hepatitis C virus core region and genetic variation near the interleukin 28B gene predict viral response to telaprevir with peginterferon and ribavirin

Genetic variation near the IL28B gene and substitution of amino acid (aa) 70 and 91 in the core region of hepatitis C virus (HCV) genotype 1b can predict the response to pegylated interferon (PEG-IFN)/ribavirin combination therapy, but its impact on triple therapy of telaprevir/PEG-IFN/ribavirin is not clear. The aims of this study were to investigate the predictive factors of sustained virological response to a 12-week or 24-week regimen of triple therapy in 72 of 81 Japanese adults infected with HCV genotype 1. Overall, sustained virological response and end-of-treatment response were achieved by 61% and 89%, respectively. Especially, the sustained virological response was achieved by 45% and 67% in the 12- and 24-week regimens, respectively. Multivariate analysis identified rs8099917 near the IL28B gene (genotype TT) and substitution at aa 70 (Arg70) as significant determinants of sustained virological response. Prediction of response to therapy based on a combination of these factors had high sensitivity, specificity, and positive and negative predictive values. The efficacy of triple therapy was high in the patients with genotype TT, who accomplished sustained virological response (84%), irrespective of substitution of core aa 70. In the patients having genotype non-TT, those of Arg70 gained high sustained virological response (50%), and sustained virological response (12%) was the worst in patients who possessed both genotype non-TT and Gln70(His70).

CONCLUSION

This study identified genetic variation near the IL28B gene and aa substitution of the core region as predictors of sustained virological response to a triple therapy of telaprevir/PEG-IFN/ribavirin in Japanese patients infected with HCV genotype 1b.

IL-28B/IFN-lambda 3 drives granzyme B loading and significantly increases CTL killing activity in macaques

Type III/lambda interferons (IFNs) were discovered less than a decade ago and are still in the process of being characterized. Although previous studies have focused on the function of IFN-lambda 3 (also known as interleukin (IL)-28B) in a small animal model, it is unknown whether these functions would translate to a larger, more relevant model. Thus in the present study, we have used DNA vaccination as a method of studying the influence of IFN-lambda 3 on adaptive immune responses in rhesus macaques. Results of our study show for the first time that IFN-lambda 3 has significant influence on antigen-specific CD8(+) T-cell function, especially in regards to cytotoxicity. Peripheral CD8(+) T cells from animals that were administered IFN-lambda 3 showed substantially increased cytotoxic responses as gauged by CD107a and granzyme B coexpression as well as perforin release. Moreover, CD8(+) T cells isolated from the mesenteric lymph nodes (MLN) of animals receiving IFN-lambda 3 loaded significant amounts of granzyme B upon extended antigenic stimulation and induced significantly more granzyme B-mediated cell death of peptide pulsed targets. These data suggest that IFN-lambda 3 is a potent effector of the immune system with special emphasis on CD8(+) T-cell killing functions which warrants further study as a possible immunoadjuvant.

Lambda Interferons: New Cytokines with Old Functions

Interferon lambda (IFN-λ) is a member of the class II cytokine family, and like the other members of this family, they are small helical proteins. Since their discovery significant efforts have been made to determine their role in innate and adaptive immunity. Their strong antiviral activity, both in vitro and in vivo, has firmly established their interferon status. However, in contrast to type I interferon, only a very limited subset of cells/tissues responds to interferon lambda. In addition to inducing an antiviral state in responsive cells, recent data suggest that IFN-l plays a role in shaping the adaptive immune response. However, the data is not in complete agreement regarding the effect of IFN-λ on the adaptive immune system. Recently IFN-l has entered clinical trials against hepatitis C Virus and IFN-l is a promising future therapeutic, against different viruses replicating in responsive tissues, like that of the airway epithelia. In this review we describe the knowledge acquired during the past six years about the structure and function of interferon lambda.

Antitumor activity of type I and type III interferons in BNL hepatoma model

Hepatocellular carcinoma (HCC) occurs most commonly secondary to cirrhosis due to chronic hepatitis C or B virus (HCV/HBV) infections. Type I interferon (IFN-alpha) treatment of chronic HCV/HBV infections reduces the incidence of HCC in cirrhotic patients. However, IFN-alpha toxicity limits its tolerability and efficacy highlighting a need for better therapeutic treatments. A recently discovered type III IFN (IFN-lambda) has been shown to possess antiviral properties against HCV and HBV in vitro. In phase I clinical trials, IFN-lambda treatment did not cause significant adverse reactions. Using a gene therapy approach, we compared the antitumor properties of IFN-alpha and IFN-lambda in a transplantable hepatoma model of HCC. BALB/c mice were inoculated with syngeneic BNL hepatoma cells, or BNL cells expressing IFN-lambda (BNL.IFN-lambda cells) or IFN-alpha (BNL.IFN-alpha cells). Despite the lack of antiproliferative activity of IFNs on BNL cells, both BNL.IFN-lambda and BNL.IFN-alpha cells displayed retarded growth kinetics in vivo. Depletion of NK cells from splenocytes inhibited splenocyte-mediated cytotoxicity, demonstrating that NK cells play a role in IFN-induced antitumor responses. However, isolated NK cells did not respond directly to IFN-lambda. There was also a marked NK cell infiltration in IFN-lambda producing tumors. In addition, IFN-lambda and, to a lesser extent, IFN-alpha enhanced immunocytotoxicity of splenocytes primed with irradiated BNL cells. Splenocyte cytotoxicity against BNL cells was dependent on IL-12 and IFN-gamma, and mediated by dendritic cells. In contrast to NK cells, isolated from spleen CD11c+ and mPDCA+ dendritic cells responded directly to IFN-lambda. The antitumor activities of IFN-lambda against hepatoma, in combination with HCV and HBV antiviral activities warrant further investigation into the clinical use of IFN-lambda to prevent HCC in HCV/HBV-infected cirrhotic patients, as well as to treat liver cancer.

Interleukin-29 binds to melanoma cells inducing Jak-STAT signal transduction and apoptosis

Interleukin-29 (IL-29) is a member of the type III IFN family that has been shown to have antiviral activity and to inhibit cell growth. Melanoma cell lines were tested for expression of the IL-29 receptor (IL-29R) and their response to IL-29. Expression of IL-28R1 and IL-10R2, components of IL-29R, was evaluated using reverse transcription-PCR. A combination of immunoblot analysis and flow cytometry was used to evaluate IL-29-induced signal transduction. U133 Plus 2.0 Arrays and real-time PCR were used to evaluate gene expression. Apoptosis was measured using Annexin V/propridium iodide staining. In situ PCR for IL-29R was done on paraffin-embedded melanoma tumors. Both IL-28R1 and IL-10R2 were expressed on the A375, 1106 MEL, Hs294T, 18105 MEL, MEL 39, SK MEL 5, and F01 cell lines. Incubation of melanoma cell lines with IL-29 (10-1,000 ng/mL) led to phosphorylation of signal transducer and activator of transcription 1 (STAT1) and STAT2. Microarray analysis and quantitative reverse transcription-PCR showed a marked increase in transcripts of IFN-regulated genes after treatment with IL-29. In the F01 cell line, bortezomib-induced and temozolomide-induced apoptosis was synergistically enhanced following the addition of IL-29. In situ PCR revealed that IL-10R2 and IL-28R1 were present in six of eight primary human melanoma tumors but not in benign nevi specimens. In conclusion, IL-29 receptors are expressed on the surface of human melanoma cell lines and patient samples, and treatment of these cell lines with IL-29 leads to signaling via the Jak-STAT pathway, the transcription of a unique set of genes, and apoptosis.

Interferon-lambda induces G1 phase arrest or apoptosis in oesophageal carcinoma cells and produces anti-tumour effects in combination with anti-cancer agents

Signal pathways of novel type III interferons (IFN-lambdas) are similar to those of type I IFNs (IFN-alpha/beta) but their distinct functions have not been well characterised. We examined the growth suppressive activity of IFN-lambda1 with nine human oesophageal carcinoma cell lines expressing the IFN-lambda receptor complexes. Among them, three lines but not others showed IFN-lambda1-mediated growth suppression by inducing G1 phase arrest or apoptosis. The G1 phase arrest was accompanied by the up-regulation of p21 and dephosphorylation of retinoblastoma (Rb), and the apoptosis was evidenced by cleavage of caspase-3 and poly (ADP-ribose) polymerase (PARP). Similar but not identical susceptibility was found in IFN-alpha-treated oesophageal carcinoma cells. Despite the differential suppressive responses among the cells, all the cells increased the expression of the myxovirus resistance A (MxA) and 2',5'-oligoadenylate synthetase (2',5'-OAS) genes and class I antigens of the major histocompatibility complexes (MHC) with IFN-lambda1 treatment. Fibroblasts and mesenchymal stem cells, positive for IFN-alpha receptor (IFNAR), lacked one of the IFN-lambda receptor complexes and Het-1A, immortalised oesophageal epithelium cells, were insensible to the IFN-lambda1-induced growth suppression. IFN-lambda1 produced combinatory anti-tumour effects with chemotherapeutic agents, cisplatin (CDDP) and 5-fluorouracil (5-FU), in IFN-lambda1-sensitive oesophageal carcinoma cells but not in normal or Het-1A cells, while IFN-alpha achieved the combinatory suppressive effects to normal cells. These data collectively show that IFN-lambda1 responsiveness is tissue-specific due to the restricted receptors expression and is diversified even among cells of the same lineage, and suggest that IFN-lambda1 is a potential therapeutic agent for oesophageal carcinoma without damaging surrounding tissues.

Low molecular weight polyethylenimine cross-linked by 2-hydroxypropyl-gamma-cyclodextrin coupled to peptide targeting HER2 as a gene delivery vector

Gene delivery is one of the critical steps for gene therapy. Non-viral vectors have many advantages but suffered from low gene transfection efficiency. Here, in order to develop new polymeric gene vectors with low cytotoxicity and high gene transfection efficiency, we synthesized a cationic polymer composed of low molecular weight polyethylenimine (PEI) of molecular weight of 600 Da cross-linked by 2-hydroxypropyl-gamma-cyclodextrin (HP gamma-CD) and then coupled to MC-10 oligopeptide containing a sequence of Met-Ala-Arg-Ala-Lys-Glu. The oligopeptide can target to HER2, the human epidermal growth factor receptor 2, which is often over expressed in many breast and ovary cancers. The new gene vector was expected to be able to target delivery of genes to HER2 positive cancer cells for gene therapy. The new gene vector was composed of chemically bonded HP gamma-CD, PEI (600 Da), and MC-10 peptide at a molar ratio of 1:3.3:1.2. The gene vector could condense plasmid DNA at an N/P ratio of 6 or above. The particle size of HP gamma-CD-PEI-P/DNA complexes at N/P ratios 40 was around 170-200 nm, with zeta potential of about 20 mV. The gene vector showed very low cytotoxicity, strong targeting specificity to HER2 receptor, and high efficiency of delivering DNA to target cells in vitro and in vivo with the reporter genes. The delivery of therapeutic IFN-alpha gene mediated by the new gene vector and the therapeutic efficiency were also studied in mice animal model. The animal study results showed that the new gene vector HP gamma-CD-PEI-P significantly enhanced the anti-tumor effect on tumor-bearing nude mice as compared to PEI (25 kDa), HP gamma-CD-PEI, and other controls, indicating that this new polymeric gene vector is a potential candidate for cancer gene therapy.

Innate immune signaling pathways in animals: beyond reductionism

The immune system plays a crucial role in the maintenance of the stability and equilibrium of the internal environment in living organisms. The field of animal innate immunity has been the global focus of immunological research for decades. It is now known that the functions of innate immunity inevitably rely on the action of the molecular machines of the cascades or network of immune signaling pathways. Up to date, many researches on the immune signaling pathways in animals were focused on identifying the component functions or cascade molecules in details, which essentially followed a reductionist paradigm without paying high attention to the integrated features. The main purpose of this article was dedicated to accentuating the shift of this field from a reductionist to a systemic view. First, the former part of this article made efforts to summarize the main aspects of the signaling pathways of animal innate immunity including the web resources, the recapitulation of highlighted pathways, the cross-talks, and the evolutionary considerations, which heavily emphasized the integrated characteristics of the immune signaling pathways. Subsequently, the later part of this article was based on the holistic feature of the immune signaling pathways, mainly dedicated to propose a novel hypothesis. From a whole perspective, the oscillating balance hypothesis was deliberately formulated to characterize the holistic pattern of the signaling transduction network of animal innate immune system, which might help to understand some immunological phenomena through the integral principle of the immune network.

Despite IFN-lambda receptor expression, blood immune cells, but not keratinocytes or melanocytes, have an impaired response to type III interferons: implications for therapeutic applications of these cytokines

Interferon (IFN)-lambda1, -2 and -3 (also designated as interleukin (IL)-29, IL-28alpha and IL-28beta) represent a new subfamily within the class II cytokine family. They show type I IFN-like antiviral and cytostatic activities in affected cells forming the basis for IFN-lambda1 therapy currently under development for hepatitis C infection. However, many aspects of IFN-lambdas are still unknown. This study aimed at identifying the target cells of IFN-lambdas within the immune system and the skin. Among skin cell populations, keratinocytes and melanocytes, but not fibroblasts, endothelial cells or subcutaneous adipocytes turned out to be targets. In contrast to these target cells, blood immune cell populations did not clearly respond to even high concentrations of these cytokines, despite an IFN-lambda receptor expression. Interestingly, immune cells expressed high levels of a short IFN-lambda receptor splice variant (sIFN-lambdaR1/sIL-28R1). Its characterization revealed a secreted, glycosylated protein that binds IFN-lambda1 with a moderate affinity (K(D) 73 nM) and was able to inhibit IFN-lambda1 effects. Our study suggests that IFN-lambda therapy should be suited for patients with verrucae, melanomas and non-melanoma skin cancers, apart from patients with viral hepatitis, and would not be accompanied by immune-mediated complications known from type I IFN application.

Interferon-lambdas: the modulators of antivirus, antitumor, and immune responses

IFN-lambdas, including IFN-lambda1, IFN-lambda2, and IFN-lambda3, also known as IL-29, IL-28A, or IL-28B, are a newly described group of cytokines distantly related to the type I IFNs and IL-10 family members. The IFN-lambdaR complex consists of a unique ligand-binding chain, IFN-lambdaR1 (also designated IL-28Ralpha), and an accessory chain, IL-10R2, which is shared with receptors for IL-10-related cytokines. IFN-lambdas signal through the IFN-lambdaR and activate pathways of JAK-STATs and MAPKs to induce antiviral, antiproliferative, antitumor, and immune responses. In this review, we summarize recent findings about the biology of IFN-lambdas and their pathophysiological roles in viral infection, cancer, and immune responses of the innate and adaptive arms.