Classical Interferon Research Articles

The history of interferon-stimulated genes in pregnant cattle, sheep, and pigs.

The trophectoderm of the elongating conceptuses of cattle, sheep, and pigs secrete high amounts of interferons that increase or induce the expression of interferon-stimulated genes (ISGs) in the endometrium. Research concerning ISGs, performed from 1995 through 2023, is reviewed in this manuscript. Expression of the classical interferon (IFN) stimulated genes (ISGs) increases in the endometrial stroma and glandular epithelium (GE) through activation of signal transducer and activator of transcription (STAT) signaling in response to the secretion of IFN tau (IFNT) and IFN gamma (IFNG) by the conceptuses of ruminants, including cattle and sheep, and pigs, respectively. The first of the classical ISGs to be characterized was ISG15 in cattle. Classical ISGs are not expressed by the endometrial luminal epithelium (LE) due to the expression of interferon regulatory factor 2 (IRF2) in the LE that prevents the expression of ISGs in the LE. Classical ISG expression in the endometrium serves as a reliable indicator of conceptus health and elongation in cattle. There are also nonclassical ISGs that are upregulated in endometrial LE in response to progesterone (P4) that are further stimulated by IFNT in sheep, the intracellular signaling pathway responsible for IFN effects on expression is unknown. ISGs are also upregulated in extrauterine tissues including CL and peripheral blood mononuclear cells (PBMCs). The expression of ISGs by the PBMCs of cattle serves as an early prognosticator of pregnancy. The physiological roles of ISGs remain obscure, but evidence suggests that they are at least in part involved in modifying the immune system to support endometrial remodeling necessary for the successful implantation of the conceptus. Our understanding of these ISGs is primarily the result of work from the laboratories of Drs Fuller Bazer, Thomas (Tod) Hansen, Gregory Johnson, Hakhyun Ka, Patrick Lonergan, Troy Ott, and Thomas Spencer.

Transcriptomic Changes in Response to Form of Selenium on the Interferon-Tau Signaling Mechanism in the Caruncular Tissue of Beef Heifers at Maternal Recognition of Pregnancy.

We have reported that selenium (Se) provided to grazing beef cattle in an inorganic (ISe) form versus a 1:1 mixture (MIX) of inorganic and organic (OSe) forms affects cholesterol biosynthesis in the corpus luteum (CL), the abundance of interferon tau (IFNτ) and progesterone (P4)-induced mRNAs in the caruncular (CAR) tissue of the endometrium, and conceptus length at maternal recognition of pregnancy (MRP). In this study, beef heifers were supplemented with a vitamin-mineral mix containing 35 ppm Se as ISe or MIX to achieve a Se-adequate status. Inseminated heifers were killed at MRP (d 17, n = 6 per treatment) for tissue collection. In CAR samples from MIX versus ISe heifers, qPCR revealed that mRNA encoding the thyroid regulating DIO2 and DIO3 was decreased (p < 0.05) and a complete transcriptomic analysis revealed effects on the interferon JAK-STAT1/2 pathway, including decreased expression of mRNAs encoding the classical interferon stimulated genes IFIT1, IFIT2, IFIT3, IRF1, IRF9, ISG15, OAS2, and RSAD2 (p < 0.05). Treatment also affected the abundance of mRNAs contributing to the immunotolerant environment (p < 0.05). In combination, these findings suggest more advanced preparation of the CAR and developing conceptus for implantation and to evade immune rejection by the maternal system in MIX- vs. ISe-treated heifers.

Induction of antiviral gene expression by cyclosporine A, but not inhibition of cyclophilin A or B, contributes to its restriction of human coronavirus 229E infection in a lung epithelial cell line

The development of antivirals with an extended spectrum of activity is an attractive possibility to protect against future emerging coronaviruses (CoVs). Cyclosporine A (CsA), a clinically approved immunosuppressive drug, has established antiviral activity against diverse unrelated viruses, including several CoVs. However, its antiviral mechanisms of action against CoV infection have remained elusive, precluding the rational design of non-immunosuppressive derivatives with improved antiviral activities. In this study, we evaluated the mechanisms of CsA against HCoV-229E infection in a human lung epithelial cell line. We demonstrate that the antiviral activity of CsA against HCoV-229E is independent of classical CsA target proteins, cyclophilin A or B, which are not required host factors for HCoV-229E in A549 cells. Instead, CsA treatment induces expression of antiviral genes in a manner dependent on interferon regulatory factor 1, but independent of classical interferon responses, which contributes to its inhibitory effect against HCoV-229E infection. Our results also point to a role for the HCoV-229E nucleoprotein in antagonizing activation of type I interferon, but we show that CsA treatment does not affect evasion of innate immune signalling pathways by HCoV-229E. Overall, our findings further the understanding of the antiviral mechanisms of CsA against CoV infection and highlight a novel immunomodulatory strategy to inhibit CoV infection that may inform future drug development efforts.

Insights from two independent transcriptomic studies of the bovine corpus luteum during pregnancy.

Several recent studies have used transcriptomics to investigate luteal changes during the maternal recognition of the pregnancy period in ruminants. Although these studies have contributed to our understanding of luteal function during early pregnancy, few attempts have been made to integrate information across these studies and distinguish key luteal transcripts or functions that are repeatably identified across multiple studies. Therefore, in this study, two independent studies of the luteal transcriptome during early pregnancy were combined and compared. In the first study, corpora lutea (CL) from day 20 of pregnancy were compared with CL collected on day 14 of pregnancy, prior to embryonic signaling. The cattle were nonlactating. In the second study, CL from day 20 of pregnancy were compared with CL collected from day 20 cyclic cattle that had been confirmed as not yet undergoing luteal regression. These were lactating cattle. Three methods were used to compare these two datasets, to identify key luteal regulators. In the first method, all transcripts with Benjamini-Hochberg-adjusted P-value (Q value) < 0.05 in both datasets were considered. This yielded 22 transcripts, including several classical interferon-stimulated genes, as well as regulators of transforming growth factor-beta (TGFB) and latent TGFB-binding proteins (LTBP)1 and 2. In the second, less conservative method, all transcripts with P < 0.01 and changed in the same direction in both datasets were considered. This yielded an additional 20 transcripts that were not identified in the first analysis, for a total of 42 common transcripts. These transcripts were regulators of functions such as inflammatory balance and matrix remodeling. In the third method, transcripts with Q < 0.10 were subject to pathway analysis, and common pathways were identified. Retinoic acid signaling and classical interferon signaling pathways were identified with this method. Finally, regulation by interferon tau (IFNT) was investigated. Among the 42 transcripts identified, 32 were regulated by IFNT in cultured luteal cells (Q < 0.05). Among those not regulated by IFNT were LTBP1 and 2, which are TGFB-binding proteins. In summary, common transcripts from two studies of the luteal transcriptome during early pregnancy were combined and shared changes were identified. This not only generated a list of potential key luteal regulators, which were mostly IFNT regulated, but also included transcripts not regulated by IFNT, including LTBP1 and 2.

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.

PSXVI-12 Revolutionizing in vitro endometrial cell studies: A novel methodology to obtain bovine endometrial cells

Abstract Cultured primary endometrial cells are used extensively to study uterine function in cattle. However, most protocols harvest endometrial cells from slaughtered animals at estimated stages of the estrous cycle. The goal of this study was to establish and validate an in vivo, minimally invasive, and estrous cycle stage-specific method to obtain endometrial cells for culture. In Experiment 1, the uterine body of Bos indicus-influenced cows was sampled using a cytology brush (cytobrush) 4 days post estrus (D4; n = 13). Brushes were transported in medium (DMEM/F12, 3% Penicillin/Streptomycin and 2% of Fungizone) to the laboratory at ambient temperature. Cells were cultured in medium containing 10% FBS at 5% of CO2 (38°C). Confluent cells (~7 days of culture) were sub-cultured for two subsequent passages. Pools (n = 4) of cells from 2–3 animals, were frozen, thawed, and re-plated (passage 3). The relative transcript abundance of PPIA, ACTB, KRT18, VIM, OXTR, PGR, ESR1 and IFNAR1 were analyzed by qPCR and compared among fresh cells and cells from each passage. Abundance of KRT18 and VIM transcripts was similar across passages, while PGR, ESR1, OXTR and IFNAR1 transcripts decreased by 90, 96, 84, and 82 %; respectively in cultured compared to fresh cells (P &amp;lt; 0.05). In Experiment 2, passage 3 cells were cultured for 24 hours with 0 or 1ng/mL of recombinant bovine interferon-tau (rbIFNT; n = 3 replicates/treatment). The relative expression of a classical interferon stimulated gene, ISG15, was evaluated by qPCR. Expression of ISG15 was 6-fold greater (P &amp;lt; 0.05) in the rbIFNT treated cells compared to controls. In conclusion, the culture of endometrial cells collected by cytobrush is feasible, generates a monolayer enriched in epithelial cells and may be used as a model for physiological studies involving IFNT signaling. Further experiments to ascertain the physiological relevance of this model are underway.

Myxovirus resistance protein A activates type I IFN signaling pathway to inhibit Zika virus replication

Myxovirus resistance protein A(MxA), one of the dynamin superfamily of large guanosine triphosphatase and a classical interferon stimulated gene (ISG) induced by type I interferons (IFNs), plays antiviral role in various virus infections. However, the effect of MxA on Zika virus (ZIKV) infection and its underlying mechanism remain elusive. In this study, we aimed to explore the role of MxA in ZIKV infection and its potential mechanisms. MxA overexpression was achieved by transfection with plasmid. The levels of MxA expression and ZIKV replication were assayed by both qRT-PCR and western blot. The activation status of Jak/STAT signaling pathway was evaluated at three levels: phosphorylation of STAT1 and STAT2(p-STAT1, p-STAT2) (western blot), activity of interferon sensitive response element (ISRE) (dual luciferase reporter gene assay), and the expression levels of ISGs (qRT-PCR). Our results showed that MxA overexpression inhibited ZIKV replication with no effect on virus entry. The expression levels of retinoic acid inducible gene I (RIG-I), melanoma differentiation-associated gene-5(MDA5), Toll-like receptor3(TLR3) and interferon regulatory Factor 3(IRF3), as well as IFNα and IFNβ, were increased in parallel with MxA upregulation. Interestingly, the inhibitory effect of MxA on ZIKV replication was abolished in type I IFN receptor (IFNAR) deficient cells (U5A). These data collectively supported that MxA inhibits ZIKV replication through activation of the type I IFN signaling pathway.

Competitive binding of STATs to receptor phospho-Tyr motifs accounts for altered cytokine responses.

Cytokines elicit pleiotropic and non-redundant activities despite strong overlap in their usage of receptors, JAKs and STATs molecules. We use IL-6 and IL-27 to ask how two cytokines activating the same signaling pathway have different biological roles. We found that IL-27 induces more sustained STAT1 phosphorylation than IL-6, with the two cytokines inducing comparable levels of STAT3 phosphorylation. Mathematical and statistical modeling of IL-6 and IL-27 signaling identified STAT3 binding to GP130, and STAT1 binding to IL-27Rα, as the main dynamical processes contributing to sustained pSTAT1 levels by IL-27. Mutation of Tyr613 on IL-27Rα decreased IL-27-induced STAT1 phosphorylation by 80% but had limited effect on STAT3 phosphorgylation. Strong receptor/STAT coupling by IL-27 initiated a unique gene expression program, which required sustained STAT1 phosphorylation and IRF1 expression and was enriched in classical Interferon Stimulated Genes. Interestingly, the STAT/receptor coupling exhibited by IL-6/IL-27 was altered in patients with systemic lupus erythematosus (SLE). IL-6/IL-27 induced a more potent STAT1 activation in SLE patients than in healthy controls, which correlated with higher STAT1 expression in these patients. Partial inhibition of JAK activation by sub-saturating doses of Tofacitinib specifically lowered the levels of STAT1 activation by IL-6. Our data show that receptor and STATs concentrations critically contribute to shape cytokine responses and generate functional pleiotropy in health and disease.

Hot-Melt Extrusion: An Emerging Technique for Solubility Enhancement of Poorly Water-Soluble Drugs.

The solubility of the drug is a significant aspect to be considered during manufacturing of pharmaceutical products. Poor aqueous solubility of drugs imparts depleted bioavailability. In this regard, several techniques are available for enhancing drug solubility or dissolution. However, only few of them are scalable and industrially applicable. Hot-melt extrusion (HME) is one such technique that has been widely used in the industry. It is a single-step, continuous manufacturing, and scalable method that has proved successful in improving the solubility of poorly soluble drugs. This review highlights the numerous pharmaceutical applications of HME, such as formulations of sterile implants, taste masking of unpleasant drugs, cocrystallization, salt formation, sustained and controlled release formulations, etc. It also describes various hydrophilic and hydrophobic carriers utilized in HME. This review also briefly discusses the recent advances in HME and gives an update on the currently available marketed products. The opportunities and challenges in future development of pharmaceutical products by HME technique are also discussed.

The presence of an embryo affects day 14 uterine transcriptome depending on the nutritional status in sheep. b. Immune system and uterine remodeling

Transcriptomics and bioinformatics were used to investigate the potential interactions of undernutrition and the presence of the conceptus at the time of maternal recognition of pregnancy on uterine immune system and remodeling. Adult Rasa Aragonesa ewes were allocated to one of two planes of nutrition for 28 days: maintenance energy intake (control; 5 cyclic, 6 pregnant ewes) providing 7.8 MJ of metabolisable energy and 0.5 maintenance intake (undernourished; 6 cyclic, 7 pregnant ewes) providing 3.9 MJ of metabolisable energy per ewe. Uterine gene expression was measured using Agilent 15 K Sheep Microarray chip on day 14 of estrus or pregnancy. Functional bioinformatics analyses were performed using PANTHER (Protein ANalysis THrough Evolutionary Relationships) Classification System. Pregnancy affected the expression of 18 genes in both control and undernourished ewes, underscoring the relevance for embryo-maternal interactions. Immune system evidenced by classical interferon stimulated genes were activated in control and -in a lesser extent-in undernourished pregnant vs cyclic ewes. Genes involved in uterine remodeling such as protein metabolism were also upregulated with the presence of an embryo in control and undernourished ewes. However, relevant genes for the adaptation of the uterus to the embryo were differentially expressed between pregnant vs cyclic ewes both in control and undernourished groups. Undernutrition alone led to an overall weak activation of immune system pathways both in cyclic and pregnant ewes. Data revealed that cellular and immune adaptations of the uterus to pregnancy are dependent on the nutritional status.

Drug screening identified gemcitabine inhibiting hepatitis E virus by inducing interferon-like response via activation of STAT1 phosphorylation

Exposure to hepatitis E virus (HEV) bears a high risk of developing chronic infection in immunocompromised patients, including organ transplant recipients and cancer patients. We aim to identify effective anti-HEV therapies through screening and repurposing safe-in-human broad-spectrum antiviral agents. In this study, a safe-in-human broad-spectrum antiviral drug library comprising of 94 agents was used. Upon screening, we identified gemcitabine, a widely used anti-cancer drug, as a potent inhibitor of HEV replication. The antiviral effect was confirmed in a range of cell culture models with genotype 1 and 3 HEV strains. As a cytidine analog, exogenous supplementation of pyrimidine nucleosides effectively reversed the antiviral activity of gemcitabine, but the level of pyrimidine nucleosides per se does not affect HEV replication. Surprisingly, similar to interferon-alpha (IFNα) treatment, gemcitabine activates STAT1 phosphorylation. This subsequently triggers activation of interferon-sensitive response element (ISRE) and transcription of interferon-stimulated genes (ISGs). Cytidine or uridine effectively inhibits gemcitabine-induced activation of ISRE and ISGs. As expected, JAK inhibitor 1 blocked IFNα, but not gemcitabine-induced STAT1 phosphorylation, ISRE/ISG activation, and anti-HEV activity. These effects of gemcitabine were completely lost in STAT1 knockout cells. In summary, gemcitabine potently inhibits HEV replication by triggering interferon-like response through STAT1 phosphorylation but independent of Janus kinases. This represents a non-canonical antiviral mechanism, which utilizes the innate defense machinery that is distinct from the classical interferon response. These results support repurposing gemcitabine for treating hepatitis E, especially for HEV-infected cancer patients, leading to dual anti-cancer and antiviral effects.

Understanding Fibrosis in Systemic Sclerosis: Novel and Emerging Treatment Approaches.

Over the years, our perceptions of fibrogenesis in systemic sclerosis (SSc) have advanced a lot. Herein, we review potential targets for SSc discovered in the past 3years. In recent years, metabolites have come into the limelight of SSc research. Anti-oxidants, promotor of adipogenesis, modulator of fatty acid metabolism, regulator of glucose homeostasis, and adenosine deaminase open a new door for SSc treatment. A mosaic of biolipids, especially cannabinoid receptor 2 agonist, represents a rational therapeutic approach in fibrosis. In terms of immune aspects, targeting chemokines or integrins for cell adhesion may become new approach to inhibiting fibrotic pathways. Epigenetic modulation of immune pathways has been uncovered much recently. Targeting histone modifications and lncRNAs has demonstrated therapeutic potential in SSc animal models. The classical JAK-STAT and interferon pathway drive great attention these years because of the promising potential for the drug repurposing of targeted therapies from arthritis to SSc. In fibrosis-associated developmental pathways, BMP, Hedgehog, and PU.1 are expected to offer new targets to restrain fibrosis. New targets involved in metabolic reprogramming, immunity, epigenetics together with developmental and apoptotic pathways open new avenues for therapeutic modulation in SSc.

Lipopolysaccharide restricts murine norovirus infection in macrophages mainly through NF-kB and JAK-STAT signaling pathway

The inflammasome machinery has recently been recognized as an emerging pillar of innate immunity. However, little is known regarding the interaction between the classical interferon (IFN) response and inflammasome activation in response to norovirus infection. We found that murine norovirus (MNV-1) infection induces the transcription of IL-1β, a hallmark of inflammasome activation, which is further increased by inhibition of IFN response, but fails to trigger the release of mature IL-1β. Interestingly, pharmacological inflammasome inhibitors do not affect viral replication, but slightly reverse the inflammasome activator lipopolysaccharide (LPS)-mediated inhibition of MNV replication. LPS efficiently stimulates the transcription of IFN-β through NF-ĸB, which requires the transcription factors IRF3 and IRF7. This activates downstream antiviral IFN-stimulated genes (ISGs) via the JAK-STAT pathway. Moreover, inhibition of NF-ĸB and JAK-STAT signaling partially reverse LPS-mediated anti-MNV activity, suggesting additional antiviral mechanisms activated by NF-ĸB. This study reveals additional insight in host defense against MNV infection.

Abstract PR7: Epigenetic deregulation in LSD1-deficient luminal mammary tumor cells leads to their increased metastasis via reprogramming of the immune microenvironment

Abstract It has become increasingly recognized that epigenetic deregulation makes significant contributions to metastasis. Mutations or deregulated expression of epigenetic regulators can alter expression of key cancer-related genes in tumor cells and may contribute to metastatic progression by affecting interaction of tumor cells with their immune microenvironment. LSD1 (KDM1A) is a histone demethylase that mainly serves as a transcriptional repressor by removing methyl groups from mono- and di-methylated lysine 4 on histone H3. In human breast cancer, LSD1 homozygous deletions and mutations are found in ~1-2% metastatic cases, suggesting that it may function as a metastasis suppressor. Consistent with this, in a mouse model of luminal breast cancer, MMTV-PyMT, we found that induced loss or inhibition of LSD1 led to a significant increase in lung metastasis. Characterization of the affected tumor cells showed a profound upregulation of many immune-related genes in LSD1-deficient cells, including genes for most MHC class I (MHC-I) (classical and non-classical) molecules, interferon and immune checkpoint pathways. FACS analysis revealed significant upregulation of the CD4+ T cell and monocytic myeloid-derived suppressor cell (MDSC) populations, and downregulation of CD8+ T-cell and NK-cell populations, in tumors with LSD1 deletion/inhibition. MHC-Is are ligands for inhibitory receptors on NK cells, and their interaction (e.g., interaction between a non-classical MHC-I, HLA-E [Qa-1 in mice] and CD94/NKG2A [on NK cells]) is a self-guarding mechanism to avoid killing of healthy “self” cells by NK cells. Upregulation of MHC-Is in Lsd1-null PyMT tumor cells may lead to suppression of NK cells. In fact, in a coculture system, NK cells exhibited reduced cytotoxicity toward Lsd1-null tumor cells. Under the in vivo setting, intraductal injection of PyMT tumor organoid cells to mammary glands of immunodeficient mice led to development of both primary tumors and lung metastasis; importantly, in NSG recipients (lack NK cells), both Lsd1-null and Lsd1-wild-type (wt) tumor cells formed lung metastatic lesions with similar sizes, whereas in SCID recipients (have NK cells), the sizes of metastatic lesions formed from Lsd1-wt tumor cells were significantly smaller than Lsd1-null cells. Collectively, these data suggest that epigenetic deregulation in LSD1-deficient luminal mammary tumor cells reprograms the tumor immune microenvironment, leading to reduced clearance of Lsd1-null PyMT tumor cells by NK cells, which may contribute to their increased metastasis. This study is not only important for understanding the immune mechanism underlying the metastasis-suppressive role of LSD1 in breast cancer, but also has important implications for immunotherapy: currently a strategy of combining checkpoint inhibitors with epigenetic drugs (e.g., LSD1 inhibitor) is being tested for improving immunotherapy; our study may help minimize the risk of (increased) metastasis potentially associated with this strategy. This abstract is also being presented as Poster B6. Citation Format: Dongxi Xiang, Zhe Li. Epigenetic deregulation in LSD1-deficient luminal mammary tumor cells leads to their increased metastasis via reprogramming of the immune microenvironment [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr PR7.

The gamma‐aminobutyric acid (GABA)A receptor modulates the cytokine response to rhinovirus exposure in human monocytic cells

Rhinoviral infections are a major cause of asthma exacerbations. Though productive rhinovirus infections occur predominantly in the bronchial epithelial cells of the upper airway, monocytic‐lineage cells, the most prominent immune cell in the lung, are important in establishing the inflammatory microenvironment observed during rhinoviral asthma exacerbations. Emerging evidence indicates that the gamma‐aminobutyric acid type A receptor (GABAAR) signaling system on leukocytes, airway epithelial cells and airway smooth muscle cells modulates the inflammation in the lung. We sought to determine if GABAAR signaling alters the release of inflammatory mediators from human monocyte‐derived macrophages (MDM) exposed to human rhinovirus (HRV). Results demonstrate that GABAARs on human MDMs are functional and stimulation with GABA or HRV caused GABAARs on the cell surface undergo protein kinase C (PKC)‐mediated endocytic removal and recycling, similar to that found in neurons. GABA treatment of MDMs during HRV exposure attenuated the production of HRV stimulated CCL2 and CXCL10 production by inhibiting the stress kinase June N‐terminal kinase (JNK) and increasing phosphorylation of extracellular regulated kinase (ERK). Interestingly, GABA stimulated the production of interferon‐b through the classical innate immune signaling molecules TANK binding kinase (TBK) and interferon regulated factor 3 (IRF3). Phosphorylation TBK occurred via the lysine deficient kinase (WNK) pathway after the influx of chloride ions when GABAARs are stimulated. Our findings suggest that GABA treatment of MDMs lead to a novel activation of the WNK‐TBK‐IRF3 axis implying the potential for GABA‐mediated treatment of HRV‐induced asthma exacerbations.Support or Funding InformationLawrence University, NIH grant R15 AI065505‐01A1 and NSF grant 0521112.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

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.

Running interference: Interplay between Zika virus and the host interferon response

The interferon (IFN) family of cytokines is a crucial part of the host’s ability to mount an effective immune response against viral infections. In addition to establishing an antiviral state within cells, IFNs also support the optimal activation of other key immune cell types. The ability of members of the Flaviviridae family to suppress type I IFN responses has been well-described. Of these viruses, Zika virus (ZIKV) has recently attracted international attention due to a series of major outbreaks that featured the novel association of neurological symptoms with infection. Researchers have begun to investigate the strategies ZIKV uses to evade type I IFNs, and the impact this has on the host. However, a unique feature of ZIKV infection compared to other flaviviruses is its capacity to be transmitted sexually, as well as its ability to infect and persist within reproductive tissues. As such, this raises the question of a potential role for type III IFN during ZIKV infection. In this review, we will discuss the interplay between these two classes of IFN with ZIKV, models that have been used to interrogate these interactions, and the effect this interplay has on infection and infection outcomes. We will also consider the intriguing possibility of whether ZIKV has evolved improved evasion mechanisms to suppress the IFN response in recent outbreaks.

Interferon Lambda: Toward a Dual Role in Cancer.

Interferon (IFN)-λ, a type III interferon (IFN), is a member of a new family of pleotropic cytokines that share high similarity with classical IFNs α and β (IFN-α/β), type I IFNs. IFN-λ acts as an antiviral agent and displays distinct biological functions, including tumor suppression. Although it activates the common Janus kinase (JAK) and signal transducer and activator of transcription (STAT) pathways, similar to IFN-α/β, IFN-λ differentially induces the expression of IFN-stimulated genes (ISGs). Novel evidence indicates that IFN-λ acts quite differently from IFN-α/β under both homeostasis and pathological situations. In contrast to IFN-α/β, IFN-λ is not involved in over-stimulation of the immune response or exacerbation of inflammation. However, the emergence of unexpected characteristics of IFN-λ, in the control of inflammation and promotion of immune suppression and cancer, reveals novel challenges and offers more strategic opportunities in the context of cancer and beyond. In this article, we discuss new evidence and potential consequences associated with the biology of IFN-λ and provide a different vision for building novel therapeutic strategies in oncology.

Treatment of Hepatitis C with Pegylated Interferon Alpha-2a and Ribavirin: Experience from Benin

Background: Viral hepatitis C (HCV) is common in Benin. Untreated, it can be complicated by cirrhosis and hepatocarcinoma, which are sources of death. The objectives of this work were twofold: 1) to evaluate the effectiveness and safety of treatment with classic dual interferon pegylated alpha-2a (IFN) and ribavirin therapy in Benin, and 2) to present problems related to financial accessibility to this treatment. Methods: This was a cross-sectional, descriptive and analytical study, with a retrospective collection of data from November 1, 2010 to December 31, 2015 and prospective collection from January 1, 2016 to July 31, 2016 (7 months). We included all patients treated with IFN + ribavirin for hepatitis C at CNHU/HKM. Sustained virological response (SVR) was defined as undetectable viral load C 6 months after stopping treatment. Safety was appreciated by the search for clinical and hematological adverse effects. Results: One hundred and six patients were followed for HCV, of whom 58 (54.7%) undergoing treatment (26 under standard dual therapy and 32 under direct-acting antivirals). Of the 26 patients under-conventional dual therapy, 12 (46.1%) were genotype 1, 13 (50%) genotype 2 and one (3.9%) genotype 4. In conventional dual therapy, SVR was achieved in 15 (57.7%) patients, including the genotype 4 patient, 4 out of 12 (33.3%) genotype 1 patients, and 10 out of 13 (76.9%) for genotype 2 patients. The most common side effects with this treatment were severe asthenia (23 cases), flu-like symptoms (22 cases), weight loss (21 cases) and neutropenia (22 cases), anemia and thrombocytopenia (20 of 26 cases). The overall cost of treatment per patient was 11,800,624 FCFA for genotypes 1 and 4; and 7,835,048 FCFA for genotype 2. Conclusion: The treatment of HCV with IFN + ribavirin in Benin is effective for genotype 2. But its adverse effects are manifold and its cost is high. The switch to direct-acting antivirals (more effective, better tolerated and less expensive) was therefore necessary.

Interferon α2 and interferon γ induce the degranulation independent production of VEGF-A and IL-1 receptor antagonist and other mediators from human mast cells.

BackgroundMast cells are resident immune effector cells, often studied in the context of allergic disease. Found in substantial numbers at sites of potential infection they are increased at sites of angiogenesis and can be pivotal for the sensing and clearance of a variety of pathogens. Interferons (IFNs) are cytokines that are critical for host defence against intracellular pathogens. Increased levels of IFNs are observed during viral infection and in autoimmune diseases. IFNs are also widely used therapeutically and have been examined in the therapy of severe asthma.ObjectiveTo define the selective human mast cell cytokine and chemokine response following activation with type I or type II IFN's.MethodsThe ability of both IFNα2 and IFNγ to induce cytokine production by human cord blood‐derived mast cells was examined in vitro. Cytokine and chemokine production at 6 and 24 h was assessed by multiplex protein analysis. Degranulation was assessed by β‐hexosaminidase release. Mast cells were also treated with reovirus or respiratory syncytial virus and their production of CXCL10, IL‐1 receptor antagonist (IL‐1Ra), and vascular endothelial growth factor (VEGF) examined after 24 h.ResultsIn addition to increased expression of classical IFN response genes, such as CXCL10, small but significant increases in CCL5 and IL‐17 production were observed following IFN activation. Notably, human mast cells produced both VEGF and IL‐1Ra in a dose dependent manner. These responses occurred in the absence of mast cell degranulation by a mechanism consistent with classical IFN signaling. Both reovirus and respiratory syncytial virus infection of mast cells, were also associated with IFN‐dependent IL‐1Ra expression.Conclusion and Clinical RelevanceOur findings demonstrate that IFNs have profound impact on cytokine and chemokine expression by human mast cells, alone or in the context of viral infection. Mast cell VEGF and IL‐1Ra responses to IFNs could impact the regulation of local inflammatory responses and subsequent tissue remodeling.