The Class II cytokine receptor (CRF2) family: overview and patterns of receptor–ligand interactions

Expression and function of interferon lambda receptor 1 variants

Lambda interferons (IFNLs) provide critical host defense against pathogens encountered at mucosal surfaces. In humans, IFNL signaling is regulated in part by low and cell-type restricted expression of the lambda interferon receptor 1 protein with expression restricted primarily to epithelial cells located at mucosal surfaces. This review will examine the evidence suggesting a role for IFNLR1 transcriptional variants in mediating cell responsiveness to IFNL ligand exposure and regulation of pathway activity.

The JAK-STAT pathway: from structural biology to cytokine engineering

The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway serves as a paradigm for signal transduction from the extracellular environment to the nucleus. It plays a pivotal role in physiological functions, such as hematopoiesis, immune balance, tissue homeostasis, and surveillance against tumors. Dysregulation of this pathway may lead to various disease conditions such as immune deficiencies, autoimmune diseases, hematologic disorders, and cancer. Due to its critical role in maintaining human health and involvement in disease, extensive studies have been conducted on this pathway, ranging from basic research to medical applications. Advances in the structural biology of this pathway have enabled us to gain insights into how the signaling cascade operates at the molecular level, laying the groundwork for therapeutic development targeting this pathway. Various strategies have been developed to restore its normal function, with promising therapeutic potential. Enhanced comprehension of these molecular mechanisms, combined with advances in protein engineering methodologies, has allowed us to engineer cytokines with tailored properties for targeted therapeutic applications, thereby enhancing their efficiency and safety. In this review, we outline the structural basis that governs key nodes in this pathway, offering a comprehensive overview of the signal transduction process. Furthermore, we explore recent advances in cytokine engineering for therapeutic development in this pathway.

Structural basis for the recognition of IFNAR1 by the humanized therapeutic monoclonal antibody QX006N for the treatment of systemic lupus erythematosus

Interferon (IFN) alpha/beta receptor 1 (IFNAR1) is indispensable for antiviral responses and the immune regulation. Dysregulation of the IFNAR1-mediaetd signaling pathways leads to deleterious autoimmune diseases such as systemic lupus erythematosus (SLE). QX006N, a humanized therapeutic monoclonal antibody, specifically targets human IFNAR1 and is in the clinical trial phase for treating SLE, but the molecular mechanism underlying the QX006N-mediated recognition of IFNAR1 remains unclear. Here, we report the high neutralization activities of QX006N against IFNAR1-mediated signal transduction. Meanwhile, we determine the structures of the fragment antigen-binding domain (Fab) of QX006N (QX006N-Fab) and QX006N-Fab in complex with the subdomains 1-3 of IFNAR1 (IFNAR1-SD123) at 2.87 Å and 2.68 Å resolutions, respectively. In the structure of the QX006N-Fab/IFNAR1-SD123 complex, QX006N-Fab only recognizes the SD3 subdomain of IFNAR1 by the hydrophobic, hydrogen-bonding and electrostatic interactions. Compared with the structure of the IFN/IFNAR1/IFNAR2 complex, the binding of QX006N-Fab to IFNAR1-SD3 blocks its association with IFN due to steric hindrance, which inhibits the IFN/IFNAR1/IFNAR2 complex formation for signal transduction. The results of this study provide the structural evidence for the specific targeting of IFNAR1 by the therapeutic antibody QX006N and pave the way for the rational design of antibody drugs to combat IFNAR1-related autoimmune diseases.

Identification, functional characterization and expression pattern of interferon-gamma (IFN-γ) and interferon-gamma receptor 1 (IFNGR1) in Nibea albiflora

Interferon-gamma (IFN-γ) is an inflammatory cytokine that plays a crucial role in regulating both innate and cell-mediated immune responses by binding to a receptor complex made up of IFNGR1 and IFNGR2. In this study, the complete cDNA of IFN-γ and IFNGR1 from Nibea albiflora were cloned and functionally characterized (named NaIFN-γ and NaIFNGR1), whose complete cDNA sequences were 1593 bp and 2792 bp, encoding 201 and 399 amino acids, respectively. Multiple sequence alignment and phylogenetic analysis showed that the concluded amino acids sequences of NaIFN-γ and NaIFNGR1 shared high identity with their teleost orthologues including the IFN-γ signature and nuclear localization signal (NLS) motif in NaIFN-γ and FN Ⅲ domain in NaIFNGR1. Real-time PCR showed that NaIFN-γ and NaIFNGR1 constitutively expressed in all tested tissues, such as the head-kidney, spleen, liver, kidney, gill, muscle, blood, and intestine with the highest expression of NaIFN-γ and NaIFNGR1 appearing in the liver and gill, respectively. After experiencing stimulation with Polyinosinic-polycytidylic acid (Poly (I:C)), Vibrio alginolyticus (V. alginolyticus) or Vibrio parahaemolyticus (V. parahaemolyticus), NaIFN-γ and NaIFNGR1 mRNA were up-regulated with the time-dependent model. Due to the presence of a nuclear localization signal (NLS), the subcellular localization revealed that NaIFN-γ dispersed throughout the cytoplasm and nucleus. NaIFNGR1, as a member of Cytokine receptor family B, was primarily expressed on the cell membrane. When NaIFN-γ and NaIFNGR1 were co-transfected, their fluorescence signals overlapped on the membrane of HEK 293T cells indicating the potential interaction between IFN-γ and IFNGR1. The GST-pull-down results further showed that NaIFN-γ could directly interact with the extracellular region of NaIFNGR1, further confirming the affinity between IFN-γ and IFNGR1. Taken together, the results firstly demonstrated that the NaIFN-γ ligand-receptor system existed in N.albiflora and played a pivotal part in N.albiflora's immune response against pathogenic bacterial infections, which contributed to the better understanding of the role of IFN-γ in the immunomodulatory mechanisms of teleost.

Exploring the JAK/STAT Signaling Pathway in Hepatocellular Carcinoma: Unraveling Signaling Complexity and Therapeutic Implications

Hepatocellular Carcinoma (HCC) continues to pose a substantial global health challenge due to its high incidence and limited therapeutic options. In recent years, the Janus Kinase (JAK) and Signal Transducer and Activator of Transcription (STAT) pathway has emerged as a critical signaling cascade in HCC pathogenesis. The review commences with an overview of the JAK/STAT pathway, delving into the dynamic interplay between the JAK/STAT pathway and its numerous upstream activators, such as cytokines and growth factors enriched in pathogenic livers afflicted with chronic inflammation and cirrhosis. This paper also elucidates how the persistent activation of JAK/STAT signaling leads to diverse oncogenic processes during hepatocarcinogenesis, including uncontrolled cell proliferation, evasion of apoptosis, and immune escape. In the context of therapeutic implications, this review summarizes recent advancements in targeting the JAK/STAT pathway for HCC treatment. Preclinical and clinical studies investigating inhibitors and modulators of JAK/STAT signaling are discussed, highlighting their potential in suppressing the deadly disease. The insights presented herein underscore the necessity for continued research into targeting the JAK/STAT signaling pathway as a promising avenue for HCC therapy.

Molecular characterization of nineteen cytokine receptor family B (CRFB) members, CRFB1, CRFB2, CRFB4-17, with three CRFB9 and two CRFB14 in a cyprinid fish, the blunt snout bream Megalobrama amblycephala

The class II cytokine receptor family members are receptors of class 2 helical cytokines in mammals, and are named cytokine receptor family B (CRFB) in fish. In zebrafish, sixteen members, including CRFB1, CRFB2 and CRFB4-17 were reported. With the availability of genome sequence, a total of nineteen CRFBs was identified in the blunt snout bream (Megalobrama amblycephala), including CRFB1, CRFB2, CRFB4-17 with the presence of three CRFB9 isoforms, and two CRFB14 isoforms. These CRFB molecules contain well conserved features, such as fibronectin type III (FNIII) domain, transmembrane and intracellular domains as other class II cytokine receptors, and are phylogenetically grouped into thirteen clades with their homologues from other species of fish. The CRFB genes were constitutively expressed in organs/tissues examined in the fish. The finding of more CRFB members in the bream may provide clues to understand possible receptor-ligand interaction and their diversity from an evolutionary point of view.

CC16 as an Inflammatory Biomarker in Induced Sputum Reflects Chronic Obstructive Pulmonary Disease (COPD) Severity

Purpose

The progression of an abnormal inflammatory response plays a crucial role in the lung function decline of chronic obstructive pulmonary disease (COPD) patients. Compared to serum biomarkers, inflammatory biomarkers in induced sputum would be a more reliable reflection of inflammatory processes in the airways.

Patients and Methods

A total of 102 COPD participants were divided into a mild-to-moderate group (FEV1%pred≥ 50%, n=57) and a severe-to-very-severe group (FEV1%pred<50%, n=45). We measured a series of inflammatory biomarkers in induced sputum and analyzed their association with lung function and SGRQ in COPD patients. To evaluate the relationship between inflammatory biomarkers and the inflammatory phenotype, we also analyzed the correlation between biomarkers and airway eosinophilic phenotype.

Results

We found increased mRNA levels of MMP9, LTB4R, and A1AR and decreased levels of CC16 mRNA in induced sputum in the severe-to-very-severe group. After adjustment for age, sex and other biomarkers, CC16 mRNA expression was positively associated with FEV1%pred (r=0.516, p=0.004) and negatively correlated with SGRQ scores (r=-0.3538, p=0.043). As previously known, decreased CC16 was related to the migration and aggregation of eosinophils in airway. It was also found that CC16 had a moderate negative correlation with the eosinophilic inflammation in airway (r=-0.363, p=0.045) in our COPD patients.

Conclusion

Low CC16 mRNA expression levels in induced sputum were associated with low FEV1%pred and a high SGRQ score in COPD patients. Sputum CC16 as a potential biomarker for predicting COPD severity in clinical practice might attribute to the involvement of CC16 in airway eosinophilic inflammation.

Identification and establishment of type IV interferon and the characterization of interferon-υ including its class II cytokine receptors IFN-υR1 and IL-10R2

Interferons (IFNs) are critical soluble factors in the immune system and are composed of three types, (I, II and III) that utilize different receptor complexes IFN-αR1/IFN-αR2, IFN-γR1/IFN-γR2, and IFN-λR1/IL-10R2, respectively. Here we identify IFN-υ from the genomic sequences of vertebrates. The members of class II cytokine receptors, IFN-υR1 and IL-10R2, are identified as the receptor complex of IFN-υ, and are associated with IFN-υ stimulated gene expression and antiviral activity in zebrafish (Danio rerio) and African clawed frog (Xenopus laevis). IFN-υ and IFN-υR1 are separately located at unique and highly conserved loci, being distinct from all other three-type IFNs. IFN-υ and IFN-υR1 are phylogenetically clustered with class II cytokines and class II cytokine receptors, respectively. Therefore, the finding of this IFN ligand-receptor system may be considered as a type IV IFN, in addition to the currently recognized three types of IFNs in vertebrates.

Interferons are critical soluble components of the inflammatory process and are composed of three types with associated receptor complexes. Here the authors identify and characterise the type IV interferon, IFN-υ, and identify its associated receptors, denote functionality during in vivo infection and ascertain its genomic localisation.

Bioconjugation strategies and clinical implications of Interferon-bioconjugates

Interferons (IFN) are immunomodulating, antiviral and antiproliferative cytokines for treatment of multiple indications, including cancer, hepatitis, and autoimmune disease. The first IFNs were discovered in 1957, first approved in 1986, and are nowadays listed in the WHO model list of essential Medicines. Three classes of IFNs are known; IFN-α2a and IFN-β belonging to type-I IFNs, IFN-γ a type-II IFN approved for some hereditary diseases and IFN-λs, which form the newest class of type-III IFNs. IFN-λs were discovered in the last decade with fascinating yet under discovered pharmaceutical potential. This article reviews available IFN drugs, their field and route of application, while also outlining available and future strategies for bioconjugation to further optimize pharmaceutical and clinical performances of all three available IFN classes.

Molecular Basis of Selective Cytokine Signaling Inhibition by Antibodies Targeting a Shared Receptor

Interleukin-1 (IL-1) family cytokines are potent mediators of inflammation, acting to coordinate local and systemic immune responses to a wide range of stimuli. Aberrant signaling by IL-1 family cytokine members, however, is linked to myriad inflammatory syndromes, autoimmune conditions and cancers. As such, blocking the inflammatory signals inherent to IL-1 family signaling is an established and expanding therapeutic strategy. While several FDA-approved IL-1 inhibitors exist, including an Fc fusion protein, a neutralizing antibody, and an antagonist cytokine, none specifically targets the co-receptor IL-1 receptor accessory protein (IL-1RAcP). Most IL-1 family cytokines form productive signaling complexes by binding first to their cognate receptors – IL-1RI for IL-1α and IL-1β; ST2 for IL-33; and IL-36R for IL-36α, IL-36β and IL-36γ – after which they recruit the shared secondary receptor IL-1RAcP to form a ternary cytokine/receptor/co-receptor complex. Recently, IL-1RAcP was identified as a biomarker for both AML and CML. IL-1RAcP has also been implicated in tumor progression in solid tumors and an anti-IL1RAP antibody (nadunolimab, CAN04) is in phase II clinical studies in pancreatic cancer and non-small cell lung cancer (NCT03267316). As IL-1RAcP is common to all of the abovementioned IL-1 family cytokines, targeting this co-receptor raises the possibility of selective signaling inhibition for different IL-1 family cytokines. Indeed, previous studies of IL-1β and IL-33 signaling complexes have revealed that these cytokines employ distinct mechanisms of IL-1RAcP recruitment even though their overall cytokine/receptor/co-receptor complexes are structurally similar. Here, using functional, biophysical, and structural analyses, we show that antibodies specific for IL-1RAcP can differentially block signaling by IL-1 family cytokines depending on the distinct IL-1RAcP epitopes that they engage. Our results indicate that targeting a shared cytokine receptor is a viable therapeutic strategy for selective cytokine signaling inhibition.

Phthalocyanine-based photoacoustic contrast agents for imaging and theranostics

Phthalocyanine, as an organic dye, has attracted much attention due to its high molar absorption coefficient in the near-infrared region (NIR). It is precisely because of this advantage that phthalocyanine is very beneficial to photoacoustic imaging (PAI). At present, many different strategies have been adopted to design phthalocyanine-based contrast agents with photoacoustic (PA) effect, including increasing water solubility, changing spectral properties, prolonging the circulation time, constructing activatable supramolecular nanoparticles, increasing targeting, etc. Based on this, this minireview highlighted the above ways to enhance the PA effect of phthalocyanine. What's more, the application of phthalocyanine-based PA contrast agents in biomedical imaging and image-guided phototherapy has been discussed. Finally, this minireview also provides the prospects and challenges of phthalocyanine-based PA contrast agents in order to provide some reference for the application of phthalocyanine-based PA contrast agents in biomedical imaging and guiding tumor treatment.

Interleukin-22 Deficiency Contributes to Dextran Sulfate Sodium-Induced Inflammation in Japanese Medaka, Oryzias latipes

Mucosal tissue forms the first line of defense against pathogenic microorganisms. Cellular damage in the mucosal epithelium may induce the interleukin (IL)-22-related activation of many immune cells, which are essential for maintaining the mucosal epithelial barrier. A previous study on mucosal immunity elucidated that mammalian IL-22 contributes to mucus and antimicrobial peptides (AMPs) production and anti-apoptotic function. IL-22 has been identified in several teleost species and is also induced in response to bacterial infections. However, the roles of IL-22 in teleost immunity and mucus homeostasis are poorly understood. In this study, Japanese medaka (Oryzias latipes) was used as a model fish. The medaka il22, il22 receptor A1 (il22ra1), and il22 binding protein (il22bp) were cloned and characterized. The expression of medaka il22, il22ra1, and il22bp in various tissues was measured using qPCR. These genes were expressed at high levels in the mucosal tissues of the intestines, gills, and skin. The localization of il22 and il22bp mRNA in the gills and intestines was confirmed by in situ hybridizations. Herein, we established IL-22-knockout (KO) medaka using the CRISPR/Cas9 system. In the IL-22-KO medaka, a 4-bp deletion caused a frameshift in il22. To investigate the genes subject to IL-22-dependent regulation, we compared the transcripts of larval medaka between wild-type (WT) and IL-22-KO medaka using RNA-seq and qPCR analyses. The comparison was performed not only in the naïve state but also in the dextran sulfate sodium (DSS)-exposed state. At the transcriptional level, 368 genes, including immune genes, such as those encoding AMPs and cytokines, were significantly downregulated in IL-22-KO medaka compared that in WT medaka in naïve states. Gene ontology analysis revealed that upon DSS stimulation, genes associated with cell death, acute inflammatory response, cell proliferation, and others were upregulated in WT medaka. Furthermore, in DSS-stimulated IL-22-KO medaka, wound healing was delayed, the number of apoptotic cells increased, and the number of goblet cells in the intestinal epithelium decreased. These results suggested that in medaka, IL-22 is important for maintaining intestinal homeostasis, and the disruption of the IL-22 pathway is associated with the exacerbation of inflammatory pathology, as observed for mammalian IL-22.

Interleukin-22: a potential therapeutic target in atherosclerosis

BACKGROUND

Atherosclerosis is recognized as a chronic immuno-inflammatory disease that is characterized by the accumulation of immune cells and lipids in the vascular wall. In this review, we focus on the latest advance regarding the regulation and signaling pathways of IL-22 and highlight its impacts on atherosclerosis.

MAIN BODY

IL-22, an important member of the IL-10 family of cytokines, is released by cells of the adaptive and innate immune system and plays a key role in the development of inflammatory diseases. The binding of IL-22 to its receptor complex can trigger a diverse array of downstream signaling pathways, in particular the JAK/STAT, to induce the expression of chemokines and proinflammatory cytokines. Recently, numerous studies suggest that IL-22 is involved in the pathogenesis of atherosclerosis by regulation of VSMC proliferation and migration, angiogenesis, inflammatory response, hypertension, and cholesterol metabolism.

CONCLUSION

IL-22 promotes the development of atherosclerosis by multiple mechanisms, which may be a promising therapeutic target in the pathogenesis of atherosclerosis.

Specific bioactivity of IL-22 in intestinal cells as revealed by the expression of IL-22RA1 in Mandarin fish, Siniperca chuatsi

IL-22, a multifunctional cytokine, acts as an important regulator in host immunity in mammals. IL-22 homologues have been characterized in several species of fish, with its expression found in multiple tissues/cells in fish, but its target cells have not been fully analyzed. In the present research, different organ/tissue isolated cells were examined for the expression of IL-22 and the induced IL-22 responses in mandarin fish. The mandarin fish IL-22 was found to be expressed in all these tested cells with high basal expression in intestinal cells. The HKLs showed low basal expression but significant increase in expression of IL-22 after LPS treatment or bacterial infection. Only intestinal cells showed response to IL-22 by enhanced expression of hepcidin, LEAP2 and IL-22BP, with unresponsiveness observed in other tested cells, which indicated the cell-specificity of IL-22 bioactivity in mandarin fish. One of the heterodimeric receptor components for IL-22, the IL-22RA1, was cloned in mandarin fish, with four tandem fibronectin type III (FNIII) domains identified in its extracellular part. IL-22RA1 exhibited an intestinal cell-specific expression pattern, although another receptor component of IL-22, IL-10R2, displayed constitutive expressions in all these tested cells. The present study reveals that the mandarin fish IL-22 exhibits its bioactivity in a cell-specific manner in intestinal cells, which is reflected in the restrictive expression of its receptor unit, IL-22RA1.

The roles of immune cells in atherosclerotic calcification

Atherosclerosis is the leading cause of acute cardiovascular events, and vascular calcification is an important pathological phenomenon in atherosclerosis. Recently, many studies have shown that immune cells are closely associated with the development of atherosclerosis and calcification, but there are many conflicting viewpoints because of immune system complications, such as the pro-atherosclerotic and atheroprotective effects of regulatory B cells (Bregs), T helper type 2 (Th2) cells and T helper type 17 (Th17) cells. In this review, we summarize the studies on the roles of immune cells, especially lymphocytes and macrophages, in atherosclerotic calcification. Furthermore, we prepared graphs showing the relationship between T cells, B cells and macrophages and atherosclerotic calcification. Finally, we highlight some potential issues that are closely associated with the function of immune cells in atherosclerotic calcification. Based on current research results, this review summarizes the relationship between immune cells and atherosclerotic calcification, and it will be beneficial to understand the relationship of immune cells and atherosclerotic calcification.

Integrated mRNA-seq and miRNA-seq analysis of goat fibroblasts response to Brucella Melitensis strain M5-90

Brucellosis is a globally zoonotic bacterial disease of humans and various animals including goats, sheep, and cattle. Brucella melitensis M5-90, a live attenuated vaccine strain, has been widely used to prevent brucellosis in goats and sheep. However, the molecular mechanisms governing protective immunity response in non-professional phagocytes infected with B. melitensis M5-90 have not been fully investigated, especially in goats. In our research, goat fibroblasts were used as in vitro models to determine these mechanisms by transcriptome analysis. After incubating with B. melitensis M5-90 3 h, the infected goat fibroblasts were collected at 0 h, 4 h, 24 h, 48 h and 72 h for RNA-seq. The results indicated that there were totally 11,819 differentially expressed genes (DEGs) and 777 differentially expressed (DE) miRNAs found in experiment groups compared with the control groups (|log2(Foldchange)|≥1, FDR<0.05). GO and KEGG enrichment analyses revealed that down-regulated genes were involved in the riboflavin metabolism and positive regulation of IL-8 secretion pathway. The up-regulated genes were mainly involved in adaptive immunity, including TNF signaling pathway, MAPK signaling pathway and JAK/STAT pathway. Additionally, cytokine-cytokine receptor interaction, natural killer cell mediated cytotoxicity and toll-like receptor signaling pathway, which associated with innate immunity pathways, were also induced. Based on the Pearson correlation coefficients and prediction results of TargetScan and miRanda, the miRNA-mRNA networks of NFKB1, IFNAR2 and IL10RB were constructed and verified in goat fibroblasts by qPCR, which demonstrated that goat fibroblasts displayed immunomodulatory properties. Our findings provide a deeper insight into the host miRNA-driven B. melitensis defense mechanism and reveal the transcriptome changes involved in the innate and adaptive immune response of the goats to B. melitensis infection.

Evolution of the IRF Family in Salmonids

Interferon regulatory factors (IRFs) as a family, are major regulators of the innate antiviral response in vertebrates principally involved in regulating the expression of interferons (IFNs) and interferon-stimulated genes (ISGs). To date, nine IRFs have been identified in mammals with a 10th member also found in several avian and fish species. Through genome mining and phylogenetic analysis, we identified and characterised 23 irf genes in 6 salmonid species. This larger repertoire of IRF in salmonids results from two additional whole-genome duplications which occurred in early teleosts and salmonids, respectively. Synteny analysis was then used to identify and confirm which paralogues belonged to each subgroup and a new nomenclature was assigned to the salmonid IRFs. Furthermore, we present a full set of Real-Time PCR primers for all rainbow trout IRFs, confirmed by sequencing to ensure paralogue specificity. RT PCR was then used to examine the response of all trout irf genes in vivo, following Vibrio anguillarum and poly I:C stimulation, indicating potential functional divergence between paralogues. Overall, this study presents a comprehensive overview of the IRF family in salmonids and highlights some novel roles for the salmonid-specific IRFs in immunity.

Differential Induction of Type I and III Interferons by Staphylococcus aureus

Staphylococcus aureus is a leading cause of bacterial pneumonia, and we have shown previously that type I interferon (IFN) contributes to the pathogenesis of this disease. In this study, we screened 75 S. aureus strains for their ability to induce type I and III IFN. Both cytokine pathways were differentially stimulated by various S. aureus strains independently of their isolation sites or methicillin resistance profiles. These induction patterns persisted over time, and type I and III IFN generation differentially correlated with tumor necrosis factor alpha production. Investigation of one isolate, strain 126, showed a significant defect in type I IFN induction that persisted over several time points. The lack of induction was not due to differential phagocytosis, subcellular location, or changes in endosomal acidification. A correlation between reduced type I IFN induction levels and decreased autolysis and lysostaphin sensitivity was found between strains. Strain 126 had a decreased rate of autolysis and increased resistance to lysostaphin degradation and host cell-mediated killing. This strain displayed decreased virulence in a murine model of acute pneumonia compared to USA300 (current epidemic strain and commonly used in research) and had reduced capacity to induce multiple cytokines. We observed this isolate to be a vancomycin-intermediate S. aureus (VISA) strain, and reduced Ifnb was observed with a defined mutation in walK that induces a VISA phenotype. Overall, this study demonstrates the heterogeneity of IFN induction by S. aureus and uncovered an interesting property of a VISA strain in its inability to induce type I IFN production.

A Double Edged Sword Role of Interleukin-22 in Wound Healing and Tissue Regeneration

Wound healing and tissue regeneration is an intricate biological process that involves repair of cellular damage and maintenance of tissue integrity. Cascades involved in wound healing and tissue regeneration highly overlap with cancer causing pathways. Usually, subsequent tissue damage events include release of a number of cytokines to accomplish post-trauma restoration. IL-22 is one of the cytokines that are immediately produced to initiate immune response against several tissue impairments. IL-22 is a fundamental mediator in inflammation, mucous production, protective role against pathogens, wound healing, and tissue regeneration. However, accumulating evidence suggests pivotal role of IL-22 in instigation of various cancers due to its pro-inflammatory and tissue repairing activity. In this review, we summarize how healing effects of IL-22, when executed in an uncontrollable fashion can lead to carcinogenesis.

Interleukin-22 and intestinal homeostasis: Protective or destructive?

Interleukin (IL)-22 is a member of IL-10 family cytokines with various immunologic functions. As its name implies, IL-22 is known to be secreted mainly by Th22 cells, a recently discovered lineage of CD4+ T cells. Also, Th17, Th1, natural killer cells, γδT cells, and innate immune cells along with some nonlymphoid cells have been confirmed as secondary cellular sources of IL-22. Different cell types such as bronchial and intestinal epithelial cells, keratinocytes, hepatocytes, dermal fibroblasts, and tubular epithelial cells are affected by IL-22. Both pathologic and protective roles have been attributed to IL-22 in maintaining gut homeostasis and inflammation. According to the latest fast-growing investigations, IL-22 is significantly involved in various pathologies including allergic diseases, infection, autoimmunity, and cancer development. Regulating gut immune responses, barrier integrity, and inflammation is dependent on a diverse complex of cytokines and mediators which are secreted by mucosal immune cells. Several investigations have been designed to recognize the role of IL-22 in gastrointestinal immunity. This article tries to discuss the latest knowledge on this issue and clarify the potential of IL-22 to be used in the future therapeutic approaches of intestinal disorders including inflammatory bowel diseases and colon cancer.

Cloning and characterisation of type I interferon receptor 1 in orange-spotted grouper (Epinephelus coioides) for response to nodavirus infection

Grouper is known as a highly economical teleost species in the Asian aquaculture industry; however, intensive culture activities easily cause disease outbreak, especially viral disease. For the prevention of viral outbreaks, interferon (IFN) is among the major defence systems being studied in different species. Fish type I IFNs are known to possess antiviral properties similar to mammalian type I IFNs. In order to stimulate antiviral function, IFN will bind to its cognate receptor, the type I interferon receptor (IFNAR), composed of heterodimeric receptor subunits known as IFNAR1 and IFNΑR2. The binding of type I interferon to receptors assists in the transduction of signals from the external to internal environments of cells to activate biological responses. In order to study the function of IFN, we first need to understand IFN receptors. In this study, we cloned and identified IFNAR1 in orange-spotted grouper (osgIFNAR1) and noted the up-regulated mRNA expression of the receptor and downstream effectors in the head kidney cells with cytokine treatment. The transcriptional expression of osgIFNAR1, which is characterised using polyinosinic-polycytidylic acid (poly[I:C]) and lipopolysaccharide (LPS) treatments, indicated the involvement of osgIFNAR1 in the immune response of grouper. The subcellular localisation of osgIFNAR1 demonstrated scattering across the grouper cell. Viral infection showed the negative feedback regulation of osgIFNAR1 in grouper larvae. Further loss of function of IFNAR1 showed a decreased expression of the virus. This study reported the identification of osgIFNAR1 and characterisation of receptor sensitivity towards immunostimulants, cytokine response, and viral challenge in the interferon pathway of orange-spotted grouper and possible different role of the receptor in viral production. Together, these results provide a frontline report of the potential function of osgIFNAR1 in the innate immunity of teleost.

Effects of IL-22 on cardiovascular diseases

Interleukin-22 (IL-22), which belongs to the IL-10 family, is an alpha helix cytokine specifically produced by many lymphocytes, such as Th1, Th17, Th22, ILCs, CD4+ and CD8+ T cells. In recent years, more and more studies have demonstrated that IL-22 has an interesting relationship with various cardiovascular diseases, including myocarditis, myocardial infarction, atherosclerosis, and other cardiovascular diseases, and IL-22 signal may play a dual role in cardiovascular diseases. Here, we summarize the recent progress on the source, function, regulation of IL-22 and the effects of IL-22 signal in cardiovascular diseases. The study of IL-22 will suggest more specific strategies to maneuver these functions for the effective treatment of cardiovascular diseases and future clinical treatment.

DNA-Based Photoacoustic Nanosensor for Interferon Gamma Detection

Tracking protein levels in the body is vital in both research and medicine, where understanding their physiological roles provides insight into their regulation in homeostasis and diseases. In medicine, protein levels are actively sampled since they continuously fluctuate, reflecting the status of biological systems and provide insight into patient health. One such protein is interferon gamma, a clinically relevant protein with immunoregulatory functions that play critical roles against infection. New tools for continuously monitoring protein levels in vivo are invaluable in monitoring real-time conditions of patients to allow better care. Here, we developed a DNA-based nanosensor for the photoacoustic detection of interferon gamma. This work demonstrates how we transformed a simple DNA motif, receptors, and a novel phthalocyanine dye into a proof-of-concept photoacoustic nanosensor for protein detection. Surface plasmon resonance kinetic analysis demonstrated that the nanosensor is responsive and reversible to interferon gamma with an affinity in the nanomolar range, K_D1 = 167 nM and K_D2 = 316 nM. As a reporter, our design includes a novel phthalocyanine-based photoacoustic dye that stacks in a J-aggregate, causing a 22.5% increase in signal. Upon receptor binding, the DNA structure bends to induce phthalocyanine dye stacking, resulting in a 55% increase in photoacoustic signal in the presence of 10 μM interferon gamma. This proof-of-concept nanosensor is a novel approach to the development of a photoacoustic sensor and may be adapted for other proteins of interest in the future for in vivo tracking.

Differential Regulation of Type I and Type III Interferon Signaling

Interferons (IFNs) are very powerful cytokines, which play a key role in combatting pathogen infections by controlling inflammation and immune response by directly inducing anti-pathogen molecular countermeasures. There are three classes of IFNs: type I, type II and type III. While type II IFN is specific for immune cells, type I and III IFNs are expressed by both immune and tissue specific cells. Unlike type I IFNs, type III IFNs have a unique tropism where their signaling and functions are mostly restricted to epithelial cells. As such, this class of IFN has recently emerged as a key player in mucosal immunity. Since the discovery of type III IFNs, the last 15 years of research in the IFN field has focused on understanding whether the induction, the signaling and the function of these powerful cytokines are regulated differently compared to type I IFN-mediated immune response. This review will cover the current state of the knowledge of the similarities and differences in the signaling pathways emanating from type I and type III IFN stimulation.

The generation and biological activity of a long-lasting recombinant human interferon-λ1

The previously generated recombinant human (rh) interferon (IFN)-λ1 protein has a short half-life, and this feature makes it challenging to conduct studies on potential clinical applications for rhIFN-λ1. In an attempt to overcome this difficulty, we constructed a 'long-life' version of rhIFN-λ1. This modified rhIFN-λ1, named rhIFN-λ1-CTPON, has a human chorionic gonadotropin β subunit carboxyl-terminal peptide (CTP) and an N-glycosylation sequence linked to its C-terminus. We confirmed the sequence of rhIFN-λ1-CTPON by mass spectrometry and then measured its biological activities. The results show that rhIFN-λ1-CTPON had antiviral activity and anti-proliferation activity in vitro that were similar to those of rhIFN-λ1 and that it similarly promoted natural killer cell cytotoxicity. Notably, the in vivo half-life of rhIFN-λ1-CTPON was determined to be 3-fold higher than that of rhIFN-λ1. We also assessed the anti-hepatitis B virus activity of rhIFN-λ1-CTPON; it was able to inhibit the production of the antigens HBs-Ag and HBe-Ag and induce antiviral gene expression. In conclusion, rhIFN-λ1-CTPON has a longer half-life than rhIFN-λ1 and has similar biological activities, so rhIFN-λ1-CTPON is an appropriate substitute for rhIFN-λ1 in the further study of potential clinical applications for rhIFN- λ1.

Molecular characterization and expression analysis of IL-22 and its two receptors genes in yellow catfish (Pelteobagrus filvidraco) in response to Edwardsiella ictaluri challenge

Interleukin (IL)-22, as a member of the interleukin (IL)-10 family, is an important mediator between the immune cells and epithelial tissues during infection and inflammation. This study reported the characterization and mRNA expression patterns of Pf_IL-22 gene and its cell surface-associated receptors Pf_IL-22RA1 and soluble Pf_IL-22RA2 genes in yellow catfish (Pelteobagrus filvidraco). The open reading frames (ORFs) of the Pf_IL-22, Pf_IL-22RA1 and Pf_IL-22RA2 genes were 546 bp, 1740 bp and 690 bp in length, encoding 181, 579 and 229 amino acids, respectively. Alignments of the deduced amino acid sequences present that the Pf_IL-22 has a conserved IL-10 family signature motif, and the Pf_IL-22RA1 and Pf_IL-22RA2 have two conserved fibronectin type-III domains. Quantitative real-time PCR (qPCR) analyses showed that the Pf_IL-22 and Pf_IL-22RA1 mRNAs were highly expressed in mucosal tissues such as the fin, gill, intestine, skin mucus and stomach, and were weakly expressed in the kidney, liver and head kidney of adult yellow catfish, indicating that the Pf_IL-22 transcripts may be mainly produced by mucosal immune cells/tissues in healthy yellow catfish. The mRNA expression levels of the Pf_IL-22RA2 gene were high in the muscle and liver, and were relatively low in the spleen and kidney. The mRNA expression levels of the Pf_IL-22 and its two receptor genes were significantly up-regulated in both mucosal tissues (gill, hindgut, and skin mucus) and systemic immune tissues (spleen, head kidney and blood) after Edwardsiella ictaluri challenge. These results indicated that the Pf_IL-22 and its two receptors genes might play an important role in the innate immune defense against bacterial invasion.

Interferons type II and their receptors R1 and R2 in fish species: Evolution, structure, and function

Interferon gamma (IFN-γ) is one of the key players in the immune system of vertebrates. The evolution and properties of IFN-γ and its receptors in fish species are of special interest as they point to the origin of innate immunity in vertebrates. We studied the phylogeny, biophysical and structural properties of IFN-γ and its receptors. Our phylogeny analysis suggests the existence of two groups of IFN-γ related proteins, one specific for Acanthomorpha, the other for Cypriniformes, Characiformes and Siluriformes. The analysis further shows an ancient duplication of the gene for IFN-γ receptor 1 (IFN- γR1) and the parallel existence of the duplicated genes in all current teleost fish species. In contrast, only one gene can be found for receptor 2, IFN- γR2. The specificity of the interaction between IFN- γ and both types of IFN- γR1 was determined by microscale thermophoresis measurements of the equilibrium dissociation constants for the proteins from three fish species. The measured preference of IFN- γ for one of the two forms of receptor 1agrees with the bioinformatic analysis of the coevolution between IFN- γ and receptor 1. To elucidate structural relationships between IFN-γ of fish and other vertebrate species, we determined the crystal structure of IFN-γ from olive flounder (Paralichthys olivaceus, PoliIFN-γ) at crystallographic resolution of 2.3 Å and the low-resolution structures of Takifugu rubripes, Oreochromis niloticus, and Larimichthys crocea IFN-γ by small angle X-ray diffraction. The overall PoliIFN-γ fold is the same as the fold of the other known IFN- γ structures but there are some significant structural differences, namely the additional C-terminal helix G and a different angle between helices C and D in PoliIFN-γ.

Impact of Interferon-α Receptor-1 Promoter Polymorphisms on the Transcriptome of the Hepatitis B Virus-Associated Hepatocellular Carcinoma

Background and aims

Genetic polymorphisms within the promoter of interferon-α receptor type-1 (IFNAR1) have been associated with the susceptibility to and the outcome of chronic hepatitis B virus (HBV) infection. However, the impact of these polymorphisms in the transcriptome of the HBV-associated hepatocellular carcinoma (HCC) remains largely unexplored.

Methods

Using whole-genome and exome sequencing data from The Cancer Genome Atlas project, we characterized three single-nucleotide polymorphisms (SNPs: −568G/C, −408C/T, −3C/T) and one variable number tandem repeat [VNTR: −77(GT)n] within the IFNAR1 promoter sequence in 49 HCC patients. RNAseq data from 10 genotyped HCC samples were grouped according to their −77VNTR or −3SNP genotype to evaluate the impact of these polymorphisms on the differential expression on the HCC transcriptome.

Results

There is a fourfold higher impact of the −77VNTR on the HCC transcriptome compared to the −3SNP (q < 0.1, p < 0.001). The expression of the primary IFNAR1 transcript is not affected by these polymorphisms but a secondary, HCC-specific transcript is expressed only in homozygous −77VNTR ≤8/≤8(GT)n samples (p < 0.05). At the same time, patients carrying at least one −77VNTR >8(GT) allele, presented a strong upregulation of the fibronectin-1 (FN-1) gene, which has been associated with the development of HCC. Gene Ontology and pathway enrichment analysis of the differentially expressed genes revealed a strong disruption of the PI3K–AKT signaling pathway, which can be partially triggered by the extracellular matrix FN-1.

Conclusion

The IFNAR-1 promoter polymorphisms are not involved in the expression levels of the main IFNAR-1 transcript. The −77VNTR has a regulatory role on the expression of a secondary, truncated, HCC-specific transcript, which in turn coincides with disruptions in cancer-associated pathways and in FN-1 expression modifications.

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.

IFN-λ1 in CHO cells: its expression and biological activity

BACKGROUND

Many studies have investigated the characteristics and biological activities of type III interferon (IFN), finding that it has similar features to type I IFN but also unique actions because it is recognized by a different receptor.

RESULTS

A full-length recombinant human IFN-λ1 (rhIFN-λ1) cDNA was cloned into the pDF expression vector and stably expressed in Flp-In-CHO cells. After four purification steps (ammonium sulfate precipitation, SP Sepharose chromatography, Blue Sepharose 6 fast flow affinity chromatography and molecular sieve chromatography), the rhIFN-λ1 had a purity of about 90% and was found to have the predicted biological activities. The anti-viral activity of rhIFN-λ1 was determined as 106 IU/mg using the vesicular stomatitis virus (WISH-VSV) assay system. The anti-proliferation activity of rhIFN-λ1 was measured using the MTS method and the growth inhibition ratio was 57% higher than that for recombinant human IFN-α2b (rhIFN-α2b) when the rhIFN-λ1 concentration was 1000 IU/ml. rhIFN-λ1 had lower natural killer cell cytotoxicity than rhIFN-α2b.

CONCLUSION

The Flp-In-CHO system is suitable for stably expressing rhIFN-λ1 that possesses the predicted anti-viral, anti-proliferation and natural killer cell cytotoxicity-promoting activities.

Interleukin-22 in human inflammatory diseases and viral infections

Interleukin-22 (IL22) is one of the members of IL10 family. Elevated levels of this cytokine can be seen in diseases caused by T lymphocytes, such as Psoriasis, Rheumatoid arthritis, interstitial lung diseases. IL22 is produced by different cells in both innate and acquired immunities. Different types of T cells are able to produce IL22, but the major IL22-producing T-cell is the TCD4. TH22 cell is a new line of TCD4 cells, which differentiated from naive T cells in the presence of TNFα and IL6; 50% of peripheral blood IL22 is produced by these cells. IL22 has important functions in host defense at mucosal surfaces as well as in tissue repair. In this review, we assess the current understanding of this cytokine and focus on the possible roles of IL-22 in autoimmune diseases.

Contribution of type III interferons to antiviral immunity: location, location, location

Type I interferons (IFN-α/β) and the more recently identified type III IFNs (IFN-λ) function as the first line of defense against virus infection and regulate the development of both innate and adaptive immune responses. Type III IFNs were originally identified as a novel ligand-receptor system acting in parallel with type I IFNs, but subsequent studies have provided increasing evidence for distinct roles for each IFN family. In addition to their compartmentalized antiviral actions, these two systems appear to have multiple levels of cross-regulation and act coordinately to achieve effective antimicrobial protection with minimal collateral damage to the host.

IL-22 capacitates dermal fibroblast responses to TNF in scleroderma

OBJECTIVES

Interleukin (IL) 22 mRNA in systemic sclerosis (SSc) skin and Th22 cells in SSc peripheral blood are increased, but the role of IL-22 in fibrosis development remains poorly understood.

METHODS

Biopsies were obtained from the involved skin of 15 SSc, 4 morphea and 8 healthy donors (HD). The presence of IL-22+ cells in the skin was determined by immunostaining. The in vitro response of HD and SSc fibroblasts to IL-22, IL-22 in conjunction with tumour necrosis factor (TNF) or keratinocyte conditioned medium was assessed by ELISA, radioimmunoassay (RIA), real-time PCR and western blot. The in vivo response in mice was assessed by histomorphometry.

RESULTS

IL-22+ cells were over-represented in the dermis and epidermis of morphea and in the epidermis of SSc compared with HD. The majority of dermal IL-22+ cells were T cells. Dermal fibroblasts expressed both IL-22 receptor subunits IL-10RB and IL-22RA, expression of which was enhanced by TNF and reduced by transforming growth factor (TGF)-β. IL-22 induced rapid phosphorylation of p38 and ERK1/2 in fibroblasts, but failed to induce the synthesis of chemokines and extracellular matrix components. However, IL-22 enhanced the production of monocyte chemotactic protein 1, IL-8 and matrix metalloproteinase 1 induced by TNF. Fibroblast responses were maximal in the presence of conditioned medium from keratinocytes activated by IL-22 in conjunction with TNF. Dermal thickness was maximal in mice injected simultaneously with IL-22 and TNF.

CONCLUSIONS

IL-22 capacitates fibroblast responses to TNF and promotes a proinflammatory fibroblast phenotype by favouring TNF-induced keratinocyte activation. These results define a novel role for keratinocyte-fibroblast interactions in the context of skin fibrosis.

Crystal structure of human interferon-γ receptor 2 reveals the structural basis for receptor specificity

Interferon-γ receptor 2 is a cell-surface receptor that is required for interferon-γ signalling and therefore plays a critical immunoregulatory role in innate and adaptive immunity against viral and also bacterial and protozoal infections. A crystal structure of the extracellular part of human interferon-γ receptor 2 (IFNγR2) was solved by molecular replacement at 1.8 Å resolution. Similar to other class 2 receptors, IFNγR2 has two fibronectin type III domains. The characteristic structural features of IFNγR2 are concentrated in its N-terminal domain: an extensive π-cation motif of stacked residues KWRWRH, a NAG-W-NAG sandwich (where NAG stands for N-acetyl-D-glucosamine) and finally a helix formed by residues 78-85, which is unique among class 2 receptors. Mass spectrometry and mutational analyses showed the importance of N-linked glycosylation to the stability of the protein and confirmed the presence of two disulfide bonds. Structure-based bioinformatic analysis revealed independent evolutionary behaviour of both receptor domains and, together with multiple sequence alignment, identified putative binding sites for interferon-γ and receptor 1, the ligands of IFNγR2.

Peginterferon lambda for the treatment of HBeAg-positive chronic hepatitis B: A randomized phase 2b study (LIRA-B)

BACKGROUND & AIMS

Peginterferon lambda-1a (lambda) is a Type-III interferon, which, like alfa interferons, has antiviral activity in vitro against hepatitis B virus (HBV) and hepatitis C virus (HCV); however, lambda has a more limited extra-hepatic receptor distribution. This phase 2b study (LIRA-B) evaluated lambda in patients with chronic HBV infection.

METHODS

Adult HBeAg+ interferon-naive patients were randomized (1:1) to weekly lambda (180 μg) or peginterferon alfa-2a (alfa) for 48 weeks. The primary efficacy endpoint was HBeAg seroconversion at week 24 post-treatment; lambda non-inferiority was demonstrated if the 80% confidence interval (80% CI) lower bound was >-15%.

RESULTS

Baseline characteristics were balanced across groups (lambda N=80; alfa N=83). Early on-treatment declines in HBV-DNA and qHBsAg through week 24 were greater with lambda. HBeAg seroconversion rates were comparable for lambda and alfa at week 48 (17.5% vs. 16.9%, respectively); however lambda non-inferiority was not met at week 24 post-treatment (13.8% vs. 30.1%, respectively; lambda vs. alfa 80% CI lower bound -24%). Results for other key secondary endpoints (virologic, serologic, biochemical) and post hoc combined endpoints (HBV-DNA <2000 IU/ml plus HBeAg seroconversion or ALT normalization) mostly favored alfa. Overall adverse events (AE), serious AE, and AE-discontinuation rates were comparable between arms but AE-spectra differed (more cytopenias, flu-like, and musculoskeletal symptoms observed with alfa, more ALT flares and bilirubin elevations seen with lambda). Most on-treatment flares occurred early (weeks 4-12), associated with HBV-DNA decline; all post-treatment flares were preceded by HBV-DNA rise.

CONCLUSIONS

On-treatment, lambda showed greater early effects on HBV-DNA and qHBsAg, and comparable serologic/virologic responses at end-of-treatment. However, post-treatment, alfa-associated HBeAg seroconversion rates were higher, and key secondary results mostly favored alfa. ClinicalTrials.gov number: NCT01204762.

Altered Expression of IFN-λ2 in Allergic Airway Disorders and Identification of Its Cell Origins

This study investigated the expression levels of interferon- (IFN-) λ2 in peripheral blood and tissues. The results showed that the levels of IFN-λ2 were elevated by 17.9% and 14.2% in the plasma of allergic rhinitis (AR) and combined rhinitis with asthma (AR + AS), which was positively correlated with the level of tryptase but negatively correlated with the level of IL-10. IFN-λ2 was predominately expressed in the CD16+ cells and CD14+ cells in healthy control subjects (HC) but upregulated only in CD8+ cells of AR and in eosinophils of asthma. It was observed that approximately 6.6% and 7.0% dispersed tonsil cells and 5.8% and 0.44% dispersed lung cells are IFN-λ2+ mast cells and macrophages. Moreover, tryptase and agonist peptides of PAR-2 induced enhanced IFN-λ2 mRNA expression in A549 cells. In conclusion, the elevated levels of IFN-λ2 in the plasma of AR and AR + AS indicate that IFN-λ2 is likely to contribute to the pathogenesis of allergic airway disorders. The potential origins of the elevated plasma IFN-λ2 include mast cells, macrophages, and epithelial cells in tissues, neutrophils, monocytes, CD8+ T cells, and eosinophils in peripheral blood. Development of IFN-λ2 related therapy may help to treat or prevent allergic airway disorders.

The interferon receptor-1 promoter polymorphisms affect the outcome of Caucasians with HBeAg-negative chronic HBV infection

BACKGROUND & AIMS

The outcome of HBeAg-negative chronic hepatitis B virus (HBV) patients who may remain in the inactive carrier state (IC) or progress to HBeAg-negative chronic hepatitis B may be affected by the host genetic profile. Genetic polymorphisms within not only the promoter but also the coding sequence of the interferon receptor 1 (INFAR1) gene have been associated with susceptibility to chronic HBV infection, but their role on the outcomes of HBeAg-negative patients has not been evaluated. We examined the association of INFAR1 promoter polymorphisms with the phase of chronic HBV infection in a demographically characterized Caucasian cohort of 183 consecutive HBeAg-negative chronic HBV patients.

METHODS

Using a combination of conventional and allele-specific polymerase chain reactions, bidirectional sequencing and DNA-fragment analysis, we performed typing of three Single Nucleotide Polymorphisms (SNPs -568G/C, -408C/T, -3C/T) and one Variable Number Tandem Repeat [VNTR -77(GT)n] within the INFR1 promoter sequence.

RESULTS

The genetic polymorphisms examined were found to be associated with the phase of HBeAg-negative chronic HBV patients. Using a multiple logistic regression model adjusting for age, gender and origin of the individuals, we found that patients with linked genotypes -408CT_-3CT were more likely to be ICs (OR = 2.42 vs. CC, P = 0.036). Also, given the partial linkage between SNP -568G/C and VNTR -77(GT)n, we found that linked genotypes -77(GT)n ≤ 8/≤8_-568GC and -77(GT)n ≤ 8/≤8_-568CC were detected more frequently among ICs (OR = 11.69, P = 0.005 and OR = 7.56, P = 0.001 vs. -77(GT)n >8/>8_-568GG respectively).

CONCLUSIONS

These findings suggest that these genetic variations represent important factors associated with the clinical phase of HBeAg-negative chronic HBV infection.

IFN-lambda therapy: current status and future perspectives

Interferon-lambda (IFN-λ), the most recently described type III IFN, plays a crucial part by acting on specific cell types, controlling viral infections and establishing robust innate immunity against cancer. In contrast to IFN-α or IFN-γ, IFN-λ has a restricted cell response pattern, which could make this new IFN a better choice for disease targeting and reducing adverse events. Although IFN-λ is considered to have pivotal roles in cancer, viral infections and autoimmune diseases, clinical trials have only been conducted for treatment of chronic hepatitis C virus infection. In this review, we discuss the current and the potential clinical applications of IFN-λ in the context of current IFN therapy.

Activation of transmembrane cell-surface receptors via a common mechanism? The "rotation model"

It has long been thought that transmembrane cell-surface receptors, such as receptor tyrosine kinases and cytokine receptors, among others, are activated by ligand binding through ligand-induced dimerization of the receptors. However, there is growing evidence that prior to ligand binding, various transmembrane receptors have a preformed, yet inactive, dimeric structure on the cell surface. Various studies also demonstrate that during transmembrane signaling, ligand binding to the extracellular domain of receptor dimers induces a rotation of transmembrane domains, followed by rearrangement and/or activation of intracellular domains. The paper here describes transmembrane cell-surface receptors that are known or proposed to exist in dimeric form prior to ligand binding, and discusses how these preformed dimers are activated by ligand binding.

Receptor tyrosine kinases: Characterisation, mechanism of action and therapeutic interests for bone cancers

Bone cancers are characterised by the development of tumour cells in bone sites, associated with a dysregulation of their environment. In the last two decades, numerous therapeutic strategies have been developed to target the cancer cells or tumour niche. As the crosstalk between these two entities is tightly controlled by the release of polypeptide mediators activating signalling pathways through several receptor tyrosine kinases (RTKs), RTK inhibitors have been designed. These inhibitors have shown exciting clinical impacts, such as imatinib mesylate, which has become a reference treatment for chronic myeloid leukaemia and gastrointestinal tumours. The present review gives an overview of the main molecular and functional characteristics of RTKs, and focuses on the clinical applications that are envisaged and already assessed for the treatment of bone sarcomas and bone metastases.

Role of Interferon-λ in Allergic Asthma

Type III interferons (IFNs), or IFN-λ, are known to have potent antiviral and antiproliferative activities. It inhibits viral replication and upregulates cytotoxic responses to virally infected cells. Besides these characteristics, IFN-λ also has additional activities in the immune system. In fact, it induces the proliferation of Foxp3-expressing regulatory T cells mediated in part by dendritic cells and inhibit the production of IL-5 and IL-13 in vitro. Regulatory T cells and the Th2 cytokines like IL-5 and IL-13 play important roles in the pathogenesis of allergic asthma. In humans, there seems to be an inverse link between IFN-λ and the severity of allergic asthma and allergic asthma exacerbations. Asthmatic patients, without a detectable viral infection show an inverse correlation between IL-28 and IL-29 mRNA levels and severity of allergic responses in the airways. These additional features of IFN-λ that affect the adaptive immune system make it a potential immunotherapeutic agent for the treatment of allergic asthma.

Molecular characterisation of four class 2 cytokine receptor family members in rainbow trout, Oncorhynchus mykiss

The interleukin (IL)-10 cytokine family includes IL-10, IL-19, IL-20, IL-22, IL-24, IL-26 and the lambda/type III interferons. They are highly pleiotropic and mediate a variety of activities, including immune suppression and antibacterial immunity. To exert their functions they signal through a heterodimeric receptor composed of a subunit with a long intracellular domain (R1 type receptors; IL-10R1, IL-20R1 or IL-22R1) and a subunit with a short intracellular domain (R2 type receptors; IL-10R2 or IL-20R2). In this study we report the identification of three R1 type receptors (named IL-10R1/CRFB7, IL-20R1a/CRFB8a and IL-20R1b/CRFB8b) and one R2 type receptor (named IL-10R2/CRFB4) in rainbow trout. The nomenclature of the receptors was supported by homology analysis, conserved motifs and phylogenetic tree analysis, confirming they belong to the piscine class 2 cytokine receptor family. For instance, they all displayed the presence of characteristic features, such as conserved fibronectin type-III domains. Expression analysis in tissues collected from healthy fish revealed different patterns of expression for each receptor, suggesting their potential involvement in different types of immune responses. When studying the modulation of the genes in cell lines and primary cultures, a greater effect was observed in the cell lines, where the expression of most receptors was affected by incubation with microbial mimics (LPS and PolyI:C) or the pro-inflammatory cytokine rIFN-γ. In addition, expression of the four receptors was modulated by viral infection, suggesting a potential involvement of such receptors and their ligands in antiviral defence.

Interferons and Their Receptors in Birds: A Comparison of Gene Structure, Phylogenetic Analysis, and Cross Modulation

Interferon may be thought of as a key, with the interferon receptor as the signal lock: Crosstalk between them maintains their balance during viral infection. In this review, the protein structure of avian interferon and the interferon receptor are discussed, indicating remarkable similarity between different species. However, the structures of the interferon receptors are more sophisticated than those of the interferons, suggesting that the interferon receptor is a more complicated signal lock system and has considerable diversity in subtypes or structures. Preliminary evolutionary analysis showed that the subunits of the interferon receptor formed a distinct clade, and the orthologs may be derived from the same ancestor. Furthermore, the development of interferons and interferon receptors in birds may be related to an animal’s age and the maintenance of a balanced state. In addition, the equilibrium between interferon and its receptor during pathological and physiological states revealed that the virus and the host influence this equilibrium. Birds could represent an important model for studies on interferon’s antiviral activities and may provide the basis for new antiviral strategies.

Standardization of human IL-29 (IFN-λ1): establishment of a World Health Organization international reference reagent for IL-29 (IFN-λ1)

Human interleukin-29 (IL-29), a helical cytokine with interferon-like activities, is currently being developed as a clinical biotherapeutic to treat chronic hepatitis C infection and some cancers. As such, the World Health Organization (WHO) has recognized a need for biological standardization of IL-29 and the establishment of an internationally available reference reagent of IL-29. In order to accomplish this, an international collaborative study that evaluates WHO candidate reference reagents of IL-29 was instigated by the National Institute for Biological Standards and Control (NIBSC) in 2010 and was carried out in the succeeding year. Two preparations of human sequence recombinant IL-29, one expressed in murine NS0 cells and the other in Escherichia coli, were formulated and lyophilized at NIBSC before evaluation in the collaborative study for their suitability to serve as a reference reagent. The preparations were tested by 6 laboratories from 4 countries using in vitro bioassays and also evaluated for thermal stability within the NIBSC laboratory. On the basis of the results of the collaborative study, both preparations, 07/212 (NS0-derived) and 10/176 (E. coli-derived) were judged sufficiently active and stable to serve as a reference reagent. However, since IL-29 produced in E. coli is in development for clinical applications, it was recommended that the preparation coded 10/176 be established as the WHO international reference reagent for human IL-29. This recommendation was accepted, and the IL-29 preparation coded 10/176 was formally established by the WHO ECBS at its meeting in October 2012 as the WHO international reference reagent for IL-29 with an assigned unitage of 5,000 reference units per ampoule.

Effect of human interferon-λ1 recombinant adenovirus on a gastric cancer orthotopic transplantation model

The aim of the present study was to investigate the effect of human interferon-λ1 recombinant adenovirus (r-Ad-hIFN-λ1) on gastric carcinoma. Human SGC-7901 cells were utilized to create an orthotopic implantation model of gastric cancer in nude mice through sterile surgery. The mice were randomly divided into three groups: Phosphate-buffered saline control (blank), adenovirus encoding bacterial β-galactosidase (Ad-Lac Z) empty vector and r-Ad-hIFN-λ1. Tumor size was measured every seven days. After three weeks of treatment, the tumors in the mice were detected by abdominal B ultrasound. The cDNA of IFN-λ1 expression in skeletal muscle was detected by a reverse transcription polymerase chain reaction and IFN-λ1 protein expression in the tumors was detected by western blot analysis and immunohistochemistry. Flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assays were conducted to analyze the proportion of natural killer (NK) cells in the spleen and the rate of cell apoptosis in tumor paraffin sections. Prior to sacrifice, the size of the tumors in the r-Ad-hIFN-λ1, Ad-Lac Z and blank groups was 184.29±10.84 mm³, 234.62±10.59 mm³ and 253.18±7.69 mm³, respectively (P<0.001). The lymph node metastasis in the abdominal cavity was 0% in the r-Ad-hIFN-λ1 group, 50% in the Ad-Lac Z group and 80% in the blank group (P<0.005). Furthermore, IFN-λ1 mRNA and protein were highly expressed in the r-Ad-hIFN-λ1 group, and the apoptosis rate in the r-Ad-hIFN-λ1 group was higher than that in the Ad-Lac Z and blank groups. The proportion of NK cells in the spleens of nude mice in the r-Ad-hIFN-λ1, Ad-Lac Z and blank groups was 26.53±1.54, 17.70±1.09 and 16.35±1.43%, respectively (P<0.001). The TUNEL results showed there was significantly more severe apoptosis in the r-Ad-hIFN-λ1 group than that in the two other groups. The apoptosis indices in the r-Ad-hIFN-λ1, Ad-Lac Z and blank groups were 0.772±0.075, 0.329±0.169 and 0.265±0.049, respectively. In conclusion, the r-Ad-hIFN-λ1 significantly inhibited human gastric cancer, possibly by promoting apoptosis of the tumors and stimulating immunological function.

Identification of grass carp IL-10 receptor subunits: functional evidence for IL-10 signaling in teleost immunity

Although the functions of teleost IL-10 have been preliminarily determined, functional evidence for its receptor signaling is lacking. Particularly, the identity of fish IL-10 receptor 2 (IL-10R2) is ambiguous. Cytokine receptor family member b4 (CRFB4) and CRFB5 are likely the ortholog of mammalian IL-10R2. In this study, grass carp CRFB4 (gcCRFB4) and gcCRFB5 cDNAs were isolated and characterized. The relatively high expression levels of grass carp IL10 receptor 1 (gcIL-10R1), gcCRFB4 and gcCRFB5 in immune tissues and cells implied their importance in fish immunity. Accordingly, gcIL-10R1, gcCRFB4 and gcCRFB5 were overexpressed in a grass carp kidney cell line to identify the IL-10 receptor subunits upon grass carp IL-10 (gcIL-10) treatment. Results showed that gcIL-10R1 was essential for gcIL-10 stimulation on STAT3 activation and grass carp suppressor of cytokine signaling 3 (gcSOCS3) promoter activity, and also indicated that gcCRFB4 but not gcCRFB5 might be the ortholog of mammalian IL-10R2. Furthermore, mutation of a putative STAT3-binding element in gcSOCS3 promoter attenuated the stimulation of gcIL-10 on gcSOCS3 promoter activity, indicating that gcIL-10 may modulate gcSOCS3 transcription at least partly via STAT3 activation. This notion was further supported by our observation that gcIL-10 was able to induce STAT3 phosphorylation and STAT3 inhibitor could abolish the upregulation of gcSOCS3 mRNA expression by gcIL-10 in grass carp head kidney leukocytes. Taken together, this study for the first time functionally characterized the teleost IL-10 receptor subunits and clarified the conservation of fish IL-10 signaling during evolution, thus laying the ground for further understanding the critical immune events led by IL-10 in teleost.

A new mechanism for growth hormone receptor activation of JAK2, and implications for related cytokine receptors

The growth hormone receptor was the first cytokine receptor to be cloned and crystallized, and provides a valuable exemplar for activation of its cognate kinase, JAK2. We review progress in understanding its activation mechanism, in particular the molecular movements made by this constitutively dimerized receptor in response to ligand binding, and how these lead to a separation of JAK-binding Box1 motifs. Such a separation leads to removal of the pseudokinase inhibitory domain from the kinase domain of a partner JAK2 bound to the receptor, and vice versa, leading to apposition of the kinase domains and transactivation. This may be a general mechanism for class I cytokine receptor action.