IFN-λ Research Articles

Innate Immune Response to Influenza Virus at Single-Cell Resolution in Human Epithelial Cells Revealed Paracrine Induction of Interferon Lambda 1.

Early interactions of influenza A virus (IAV) with respiratory epithelium might determine the outcome of infection. The study of global cellular innate immune responses often masks multiple aspects of the mechanisms by which populations of cells work as organized and heterogeneous systems to defeat virus infection, and how the virus counteracts these systems. In this study, we experimentally dissected the dynamics of IAV and human epithelial respiratory cell interaction during early infection at the single-cell level. We found that the number of viruses infecting a cell (multiplicity of infection [MOI]) influences the magnitude of virus antagonism of the host innate antiviral response. Infections performed at high MOIs resulted in increased viral gene expression per cell and stronger antagonist effect than infections at low MOIs. In addition, single-cell patterns of expression of interferons (IFN) and IFN-stimulated genes (ISGs) provided important insights into the contributions of the infected and bystander cells to the innate immune responses during infection. Specifically, the expression of multiple ISGs was lower in infected than in bystander cells. In contrast with other IFNs, IFN lambda 1 (IFNL1) showed a widespread pattern of expression, suggesting a different cell-to-cell propagation mechanism more reliant on paracrine signaling. Finally, we measured the dynamics of the antiviral response in primary human epithelial cells, which highlighted the importance of early innate immune responses at inhibiting virus spread.IMPORTANCE Influenza A virus (IAV) is a respiratory pathogen of high importance to public health. Annual epidemics of seasonal IAV infections in humans are a significant public health and economic burden. IAV also causes sporadic pandemics, which can have devastating effects. The main target cells for IAV replication are epithelial cells in the respiratory epithelium. The cellular innate immune responses induced in these cells upon infection are critical for defense against the virus, and therefore, it is important to understand the complex interactions between the virus and the host cells. In this study, we investigated the innate immune response to IAV in the respiratory epithelium at the single-cell level, providing a better understanding on how a population of epithelial cells functions as a complex system to orchestrate the response to virus infection and how the virus counteracts this system.

Impact of IFNL4 Genetic Variants on Sustained Virologic Response and Viremia in Hepatitis C Virus Genotype 3 Patients

Hepatitis C virus (HCV) genotype 3 is very prevalent in Europe and Asia and is associated with worst outcomes than other genotypes. Genetic factors have been associated with HCV infection; however, no extensive genome-wide study has been performed among HCV genotype 3 patients. In this study, using a large cohort of 1,759 patients infected with HCV genotype 3, we explore the role of genetic variants on the response to interferon (IFN) and direct-acting antiviral (DAA) regimens and viremia in a combined candidate gene and genome-wide analysis. We show that genetic variants within the IFN lambda 4 (IFNL4) locus are the major factors associated with the studied traits, accordingly with observations in other HCV genotypes and with comparable effect sizes. In particular, the functional dinucleotide polymorphism rs368234815 was associated with IFN-based sustained virologic response (SVR) [odds ratio (OR) = 1.5, P = 2.3 × 10−7], viremia (beta = −0.23, P = 8.8 × 10−10), and also DAA-based SVR (OR = 1.7; P = 4.2 × 10−4). Our results provide evidence for a role of genetic variants on HCV viremia and SVR, notably DAA-based, in patients infected with HCV genotype 3.

Genetics of the Human Interferon Lambda Region.

Humans are polymorphic in their ability to produce type-III interferons. Most individuals of African ancestry are genetically capable of generating all 4 type-III interferons (IFN-λ1, 2, 3, and 4), whereas the majority of individuals of European and Asian ancestry lack IFN-λ4 and thus can generate only IFN-λ1, 2, and 3. All 4 type-III IFNs are encoded by genes located within a ∼55 kb genomic region on human chromosome 19. Although IFN-λ4 appears to be important in animals, genetic alterations acquired in the Hominidae lineage, and particularly in humans, resulted in the elimination of IFN-λ4 or restriction of its activity, suggesting that IFN-λ4 function might be detrimental to human health. Genetic variants within the IFNL region, including those controlling production and activity of IFN-λ4, have been strongly associated with clearance of hepatitis C virus (HCV) infection. There is growing evidence for association of the same genetic variants with a multitude of other disease conditions. This article reviews the genetic landscape of the human IFNL genetic locus, with an emphasis on the genetic control of IFN-λ4 production and activity, and its association with viral clearance.

Interferon lambda 4 impacts the genetic diversity of hepatitis C virus.

Hepatitis C virus (HCV) is a highly variable pathogen that frequently establishes chronic infection. This genetic variability is affected by the adaptive immune response but the contribution of other host factors is unclear. Here, we examined the role played by interferon lambda-4 (IFN-λ4) on HCV diversity; IFN-λ4 plays a crucial role in spontaneous clearance or establishment of chronicity following acute infection. We performed viral genome-wide association studies using human and viral data from 485 patients of white ancestry infected with HCV genotype 3a. We demonstrate that combinations of host genetic variants, which determine IFN-λ4 protein production and activity, influence amino acid variation across the viral polyprotein - not restricted to specific viral proteins or HLA restricted epitopes - and modulate viral load. We also observed an association with viral di-nucleotide proportions. These results support a direct role for IFN-λ4 in exerting selective pressure across the viral genome, possibly by a novel mechanism.

Adaptation of hepatitis C virus to interferon lambda polymorphism across multiple viral genotypes.

Genetic polymorphism in the interferon lambda (IFN-λ) region is associated with spontaneous clearance of hepatitis C virus (HCV) infection and response to interferon-based treatment. Here, we evaluate associations between IFN-λ polymorphism and HCV variation in 8729 patients (Europeans 77%, Asians 13%, Africans 8%) infected with various viral genotypes, predominantly 1a (41%), 1b (22%) and 3a (21%). We searched for associations between rs12979860 genotype and variants in the NS3, NS4A, NS5A and NS5B HCV proteins. We report multiple associations in all tested proteins, including in the interferon-sensitivity determining region of NS5A. We also assessed the combined impact of human and HCV variation on pretreatment viral load and report amino acids associated with both IFN-λ polymorphism and HCV load across multiple viral genotypes. By demonstrating that IFN-λ variation leaves a large footprint on the viral proteome, we provide evidence of pervasive viral adaptation to innate immune pressure during chronic HCV infection.

What makes the hepatitis C virus evolve?

Polymorphisms in the IFNL4 gene that affect both the presence and the form of the coded protein are associated with changes in the hepatitis C virus.

The influence of interleukin 28B polymorphisms on the risk of hepatocellular carcinoma among patients with HBV or HCV infection: An updated meta-analysis.

Single nucleotide polymorphisms (SNPs) of the interleukin 28B (IL28B) gene has proven to be associated with the clinical outcome of patients with chronic hepatitis virus B or C (HBV or HCV) infections. However, whether IL28B SNPs have an influence on the risk of hepatocellular carcinoma (HCC) among patients with HBV or HCV infection remains controversial. Therefore, this study aims to determine the association between IL28B polymorphisms and the risk of HCC in individuals with HBV or HCV infection.PubMed, EMBASE, and Chinese National Knowledge Infrastructure (CNKI) databases were used to identify studies meeting the selection requirements using the terms “interleukin 28B”, “IFN-lambda-3”, “IFNL3”, “single nucleotide polymorphisms”, “SNPs”, “hepatocellular carcinoma”, “HCC”, “liver cancer”.A total of 24 eligible original studies (1 cohort study and 23 case-control studies) involved 20238 individuals (HCC group = 8725 vs control group = 11,513) were included. Both IL28B rs12979860 CC and rs8099917 TT genotypes were significantly associated with a decreased risk of HCC among patients with HBV or HCV infection (OR = 0.71, 95% CI = 0.57–0.88; OR = 0.82, 95% CI = 0.72–0.94, respectively). Egger test and Begg test revealed no‘ publication bias (P > .05). Sensitivity analyses suggested the robustness of the results in this meta-analysis.Both IL28B rs12979860 CC and rs8099917 TT genotypes are protective factors for the development of HCC among patients with HBV or HCV infection. Future prospective studies examining the impact of IL28B polymorphisms on the risk of HCC and investigating the underlying mechanism for the protective role of IL28B polymorphisms in HCC development are warranted.

Structure-based glycoengineering of interferon lambda 4 enhances its productivity and anti-viral potency

Interferon lambda 4 (IFNλ4) has been recently known and studied for its role in hepatitis C virus (HCV) infection, but its clinical potential is significantly hampered due to its poor expression in vitro. Our study reports the successful production of IFNλ4 from a mammalian cell line through a glycoengineering and structure-based approach. We introduced de novo N-glycosylation of IFNλ4, guided by structural analysis, and produced IFNλ4 variants in Expi293F that displayed improved expression and potency. To preserve the structure and functionality of IFNλ4, the model structure of the IFNλ4 signaling complex was analyzed and the N-glycosylation candidate sites were selected. The receptor binding activity of engineered IFNλ4 variants and their receptor-mediated signaling pathway were similar to the E. coli version of IFNλ4 (eIFNλ4), while the antiviral activity and induction levels of interferon-stimulated gene (ISG) were all more robust in our variants. Our engineered IFNλ4 variants may be further developed for clinical applications and utilized in basic research to decipher the immunological roles of IFNλ4.

Inosine triphosphate pyrophosphatase polymorphisms are predictors of anemia in Chinese patients with chronic hepatitis C during therapy with ribavirin and interferon.

Polymorphisms of inosine triphosphate pyrophosphatase (rs1127354 and rs6051702) and interferon lambda 4 (IFLN4) (rs12979860) are indicators of anemia and/or sustained virological response (SVR) in patients with chronic hepatitis C on ribavirin/interferon. The study aims to investigate the associations of rs1127354, rs6051702, and rs12979860 with hemoglobin levels and SVR in patients on ribavirin/interferon. Polymorphisms were detected by pyrosequencing. Levels of hemoglobin and hepatitis C virus (HCV) RNA were measured at weeks 2, 4, 12, 24, 36, 48, and 72 of treatment. A total of 351 patients (median age, 50years; male, 71.2%) were recruited and had HCV genotypes 1b (55.8%) or 2a (37.0%). Vedian baseline hemoglobin and HCV RNA were 155g/dL and 6.07 log10 IU/mL. Major allele homozygosity was observed in 76.3% for rs1127354 (CC), 70.9% for rs6051702 (AA), and 89.7% for rs12979860 (CC). At 4weeks of ribavirin/interferon treatment, a more significant reduction in hemoglobin was observed with rs112754 CC than with AC/AA (P<0.05). A decline ≥3g/dL was more common in patients with the rs112754 CC than with the other two polymorphisms. No significant change was observed regarding rs6051702 and rs12979860 variants. In the multivariable analysis, rs1127354 AA/AC (vs CC) were independently associated with lower odds of hemoglobin decline of >3g/dL at 4weeks (odds ratio, 0.21; 95% CI, 0.09-0.46; P<0.0001). In 258 patients with 72-week outcome data available, rs1127354, rs6051702, and rs12979860 were not associated with SVR (all P>0.05). rs1127354 polymorphisms are associated with hemoglobin levels in Chinese patients with chronic hepatitis C treated with ribavirin/interferon.

Germinal Immunogenetics predict treatment outcome for PD-1/PD-L1 checkpoint inhibitors

Background Checkpoint inhibitors bring marked benefits but only in a minority of patients and may also be associated with severe adverse events. Treatment outcome still cannot be faithfully predicted. The following study hypothesized that host genetics could be applied as predictive biomarkers for checkpoint inhibitor response and immune-related adverse events. We conducted a study based on germinal polymorphisms from genes coding for proteins involved in immune regulation. Methods Germinal DNA was obtained from advanced cancer patients treated with anti-PD-1/PD-L1 checkpoint inhibitors. DNA was genotyped using a custom panel of 166 single nucleotide polymorphisms covering 86 preselected immunogenetic-related genes. Computational analysis using a GTEX portal was made to determine potential expression Quantitative Trait Loci in tissues. Results Ninety-four consecutive patients were included. Objective response rate (complete or partial response) was significantly correlated to tumor microenvironment-related SNPs concerning CCL2, NOS3, IL1RN, IL12B, CXCR3 and IL6R genes. Toxicity were linked to target-related gene SNPs including UNG, IFNW1, CTLA4, PD-L1 and IFNL4 genes. The Area Under the ROC curve (AUC) was 0.81 (95% CI: 0.72-0.9) for response and 0.89 (95% CI: 0.76-1.00) for toxicity. In silico functionality exploring pointed rs4845618 (IL6R), rs10964859 (IFNW1) and rs3087243 (CTLA4) as potentially impacting gene expression. Conclusion These results strongly support a role for distinct immunogenetic-related gene SNPs able to predict efficacy and safety of anti-PD1/PD-L1 therapies. The results highlight the existence of patient-specific, germinal biomarkers able predict response to checkpoint inhibitor efficacy and, possibly, to predict treatment-related adverse events.

Interferon Lambda Promotes Paneth Cell Death Via STAT1 Signaling in Mice and Is Increased in Inflamed Ileal Tissues of Patients With Crohn’s Disease

Interferon lambda (IFNL) is expressed at high levels by intestinal epithelial cells (IECs) and mucosal immune cells in response to infection and inflammation. We investigated whether IFNL might contribute to pathogenesis of Crohn's disease (CD). We obtained serum samples and terminal ileum biopsies from 47 patients with CD and 16 healthy individuals (controls). We measured levels of IFNL by enzyme-linked immunosorbent assay and immunohistochemistry and location of expression by confocal microscopy. Activation of IFNL signaling via STAT1 was measured in areas of no, mild, moderate, and severe inflammation and correlated with Paneth cell homeostasis and inflammation. IFNL expression and function were studied in wild-type mice and mice with intestinal epithelial cell-specific (ΔIEC) disruption or full-body disruption of specific genes (Mlkl-/-, Stat1ΔIEC, Casp8ΔIEC, Casp8ΔIECRipk3-/-, Casp8ΔIECTnfr-/-, Casp8ΔIECMlkl-/-, and Nod2-/- mice). Some mice were given tail vein injections of a vector encoding a secreted form of IFNL. Intestinal tissues were collected from mice and analyzed by immunohistochemistry and immunoblots. We generated 3-dimensional small intestinal organoids from mice and studied the effects of IFNL and inhibitors of STAT-signaling pathway. Patients with CD had significant increases in serum and ileal levels of IFNL compared with controls. Levels of IFNL were highest in ileum tissues with severe inflammation. High levels of IFNL associated with a reduced number of Paneth cells and increased cell death at the crypt bottom in inflamed ileum samples. Intestinal tissues from the ileum of wild-type mice injected with a vector expressing IFNL had reduced numbers of Paneth cells. IFNL-induced death of Paneth cells in mice did not occur via apoptosis, but required Mixed Lineage Kinase Domain Like (MLKL) and activation of Signal transducer and activator of transcription 1 (STAT1). In organoids, inhibitors of Janus kinase (JAK) signaling via STAT1 (glucocorticoids, tofacitinib, or filgotinib) reduced expression of proteins that mediate cell death and prevented Paneth cell death. Levels of IFNL are increased in serum and inflamed ileal tissues from patients with CD and associated with a loss of Paneth cells. Expression of a secreted form of IFNL in mice results in loss of Paneth cells from intestinal tissues, via STAT1 and MLKL, controlled by caspase 8. Strategies to reduce IFNL or block its effects might be developed for treatment of patients with CD affecting the terminal ileum.

IFNL4 haplotype, linkage disequilibrium and their influence on virological response to hepatitis C virus infection in Indian population.

Type III interferon (IFNs) encoded by IFN lambda (IFNL) genes induce antiviral activity. The IFNL clusters include IFNL1/IL29, IFNL2/IL28A, IFNL3/IL28B and IFNL4 genes. The single nucleotide polymorphisms (SNPs, rs12979860 and rs8099917) associated with virological responses against hepatitis C virus (HCV) infections are recently mapped to IFNL4 gene. The IFNL gene polymorphisms also plays role in immune clearance, inflammation and risk of developing hepatocellular carcinoma. There is significant genetic heterogeneity of IFNL4 polymorphisms among ethnic populations that need to be regionally studied for viral infection, treatment response and relapse. The IFNL4 risk allele, genotype and haplotype frequencies across north Indian cohort were determined among chronic hepatitis C (CHC) cases (n = 141) and healthy controls (n = 111) by allele specific real-time PCR. Odds ratio was calculated for HCV exposure and treatment response using dominant and minor allele/genotype as reference. Non-random associations of these two SNP loci were evaluated by linkage disequilibrium plot. The minor allele (T) frequency of rs12979860C/T is 0.241 and 0.229; and minor allele (G) frequency for SNP rs8099917T/G is 0.174 and 0.171 among CHC cases and healthy control respectively. Coefficient of linkage disequilibrium (D') of these two SNPs is very high (D' = 0.98, r2 > 0.6) in CHC group than in healthy control (D' = 0.76, r2 = 0.39) which indicate that both SNPs are strongly linked in CHC population than healthy control. Favorable association of IFNL4 haplotype (C-T), genotype (CC for rs12979860 and TT for rs8099917) with anti HCV therapy were found significant (p = 0.009, 0.021 and 0.001) for SVR. Favorable genotypes are also found to be predominant across the Indian study population.

Host Genetics of Cytomegalovirus Pathogenesis.

Human cytomegalovirus (HCMV) is a ubiquitous herpes virus (human herpes virus 5) with the highest morbidity and mortality rates compared to other herpes viruses. Risk groups include very young, elderly, transplant recipient, and immunocompromised individuals. HCMV may cause retinitis, encephalitis, hepatitis, esophagitis, colitis, pneumonia, neonatal infection sequelae, inflammatory, and age-related diseases. With an arsenal of genes in its large genome dedicated to host immune evasion, HCMV can block intrinsic cellular defenses and interfere with cellular immune responses. HCMV also encodes chemokines, chemokine receptors, and cytokines. Therefore, genes involved in human viral defense mechanisms and those encoding proteins targeted by the CMV proteins are candidates for host control of CMV infection and reactivation. Although still few in number, host genetic studies are producing valuable insights into biological processes involved in HCMV pathogenesis and HCMV-related diseases. For example, genetic variants in the immunoglobulin GM light chain can influence the antibody responsiveness to CMV glycoprotein B and modify risk of HCMV-related diseases. Moreover, CMV infection following organ transplantation has been associated with variants in genes encoding toll-like receptors (TLRs), programmed death-1 (PD-1), and interleukin-12p40 (IL-12B). A KIR haplotype (2DS4+) is proposed to be protective for CMV activation among hematopoietic stem cell transplant patients. Polymorphisms in the interferon lambda 3/4 (IFNL3/4) region are shown to influence susceptibility to CMV replication among solid organ transplant patients. Interestingly, the IFNL3/4 region is also associated with AIDS-related CMV retinitis susceptibility in HIV-infected patients. Likewise, interleukin-10 receptor 1 (IL-10R1) variants are shown to influence CMV retinitis development in patients with AIDS. Results from genome-wide association studies suggest a possible role for microtubule network and retinol metabolism in anti-CMV antibody response. Nevertheless, further genetic epidemiological studies with large cohorts, functional studies on the numerous HCMV genes, and immune response to chronic and latent states of infection that contribute to HCMV persistence are clearly necessary to elucidate the genetic mechanisms of CMV infection, reactivation, and pathogenesis.

Abstract 3738: A STING independent type-1 interferon response induced by fractionated radiotherapy coincides with altered tumor growth and clonogenicity

Abstract Introduction To improve radiotherapy efficacy, insight in the dynamic biological responses that occur during clinical radiation schedules is vital. In the current study we explored gene expression changes during the course of fractionated radiotherapy (FrRT) that might be targeted with combination treatment strategies. Methods Human cell lines HT29, SW480, HCT116, COLO320, RKO (colorectal carcinoma), D384 (glioblastoma) and OE19 (esophageal adenocarcinoma) as well as HT29 xenograft tumors in nude mice were irradiated up to 3 to 5 weeks with daily fractions of 2 Gy for 5 days per week. In vivo tumor growth was monitored daily and in vitro clonogenic survival was determined every other day. At the end of each treatment week tumors and cells were harvested for RNA isolation. Subsequently, gene expression analysis was performed by RNA sequencing and micro-array analysis. Altered gene expression levels were validated by qPCR. Protein expression was determined by ELISA and Western blot. Results Tumor growth of the HT29 xenografts declined after 2 weeks of FrRT compared to non-irradiated tumors. In irradiated cell lines, clonogenic survival analyses revealed a log-linear decline in survival in the first 2 weeks, after which a steady-state-like phase was reached up to 5 treatment weeks. Gene expression analysis of both xenograft tumors as well as irradiated cell lines at this 2 week time point identified a type-1 interferon (IFN) mediated signaling pathway as the most significantly enriched biological process. The induction of a selection of IFN-stimulated genes (ISGs) was confirmed by qPCR. Comparable responses were observed in both STING positive (HT29, SW480, HCT116, D384) and negative (COLO320, RKO, OE19) cell lines. To get more insight in the dynamics of the IFN response we analyzed ISGs expression at the end of each treatment week. This revealed a peak in ISGs expression after 10 to 15 fractions, both in vivo and in vitro. The ISGs expression levels decreased with continuation of treatment but always remained above the basal level of non-irradiated cells. Single dose irradiation up to 10 Gy also induced dose-dependent ISGs expression, albeit typically 5 to 10 fold lower as compared to FrRT. Subsequent protein and mRNA expression analyses consistently revealed induction of IFN beta expression, with peak levels measured after 10 to 15 fractions. In addition, occasional induction of IFN lambda 2/3 protein and mRNA expression was observed. Conclusion FrRT induces an intrinsic type-1 IFN response which occurs independent of STING. This response is associated with induction of IFN beta expression, which peaks after 2 to 3 weeks of treatment and coincides with a shift in in vivo tumor growth and in vitro clonogenic survival. Targeting this response during FrRT might be exploited as a novel combination treatment. Citation Format: Ruben S. Goedegebuure, Esther A. Kleibeuker, Kitty C. Castricum, Jaap van den Berg, Sarah Derks, Henk M. Verheul, Ben J. Slotman, Adrian Harris, Victor L. Thijssen. A STING independent type-1 interferon response induced by fractionated radiotherapy coincides with altered tumor growth and clonogenicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3738.

The IFN-λ4 Conundrum: When a Good Interferon Goes Bad.

Since its discovery in 2013, interferon lambda 4 (IFN-λ4) has received a reputation as a paradoxical type III IFN. Difficulties in detecting IFN-λ4, especially in secreted form even led to questions about its existence. However, the genetic ability to generate IFN-λ4, determined by the presence of the rs368234815-ΔG allele, is the strongest predictor of impaired clearance of hepatitis C virus (HCV) infection in humans. Significant modulation of IFN-λ4 activity by a genetic variant (P70S) supports IFN-λ4, and not other type III IFNs encoded in the same genomic locus, as the primary functional cause of the association with HCV clearance. Although the ability to produce IFN-λ4 is associated with decreased HCV clearance, the recombinant IFN-λ4 is active against HCV and other viruses. These observations present an apparent conundrum-when and how does a presumably good IFN, with anti-HCV activity, interfere with the ability to clear HCV? In this review, we discuss findings that suggest potential mechanisms for explaining this conundrum.

Molecular characterization, constitutive expression and GTP binding mechanism of Cirrhinus mrigala (Hamilton, 1822) Myxovirus resistance (Mx) protein

Myxovirus resistance (Mx) proteins represents the subclass of the dynamin superfamily of large Guanosine triphosphates (GTPases), play esential role in intracellular vesicle trafficking, endocytosis, organelle homeostasis and mitochondria distribution. These proteins are key players of the vertebrate immune system, induced by type-I and type-III interferons (IFN) of infected host and inhibit viral replication by sequestering its nucleoprotein. In the present study, we report the sequencing and characterization of Cirrhinus mrigala Mx protein (CmMx) for the first time and observed its constitutive expression in different tissues for a period of fourteen days. The synthetic peptide, LSGVALPRGTGI, was dissolved in PBS and injected into a rabbit and the antibody raised against CmMx was used to study the level of its expression. The full length of the CmMx cDNA is 2244 bp with a molecular mass of 70.9 kDa and a predicted isoelectric point of 8.25. The 627 amino acids polypeptide formed of three main functional domains: N-terminal GTPase domain (GD), a middle domain (MD) and GTPase effector domain (GED) with carboxy terminal leucine zipper motif. The 3D models of CmMx protein was modeled based on available close structural homologs and further validated through molecular dynamics (MD) simulations. MD study revealed the importance of G-domain responsible for recognition of GTP, which perfectly corroborate with earlier studies. MM/PBSA binding free energy analysis displayed that van der Waals and electrostatic energy were the key driving force behind molecular recognition of GTP by CmMx protein. The results from this study will illuminate more lights into the ongoing research on myxovirus resistance protein and its role in inhibition of viral replication in other eukaryotic system as well.

Comparative Study of Interleukin 28B Gene in Genotype 3 Chronic Hepatitis C Patients Before and After Treated With Interferon/Pegylated in Sindh

Chronic hepatitis C (HCV) caused by hepatitis C (HCV) virus, approximately estimated 170-200 million individuals in the world including Pakistan having 10 million HCV infected . The effective available treatment option is a combination of Pegylated interferon (PegIFN) and Ribavirin (RBV) . Recently Genome wide association studies (GAWAS)supporting two single nucleotide polymorphism SNPs adjacent interleukin 28B gene associated with spontaneous and treatment induced clearance of HCV patients. The aim of the present study was to analysis the impact of response associated interleukin 28B(IL28B) single nucleotide polymorphism (SNPs) rs12979860, rs8099917 in different treatment interval with one month (RVR) and after end of treatment (SVR) with Pegylated Interferon(PEG IFN) and Ribavirin in Hepatitis C genotype 3 patients. The present study enrolled 200 HCV RNA positive genotype 3 patients having both SNPs (rs12979860, rs8099917) were analyzed by Real Time Polymerase Chain Reaction (RT-PCR). The frequency distribution of IL28B genotypes were investigated by SNIPs (rs12979860 and rs8099917) in HCV RNA positive genotype 3 patients in Pakistani population

The impact of IFNL3 genotype on interferon treatment outcome in patients chronically infected with hepatitis B virus: A meta-analysis

BackgroundPolymorphisms near the interferon lambda 3 (IFNL3, also known as IL28B) have been proposed to be associated with interferon (IFN)–induced hepatitis C virus (HCV) clearance, but the impact of IFNL3 variations on the result of IFN-based therapy in chronic hepatitis B (CHB) infection is still poor understood. MethodsThe purpose of this study was to evaluate the relationship between the IFNL3 polymorphisms and the effectiveness of IFN therapy in patients infected with CHB by means of meta-analysis. PubMed and Embase were utilized to identify relevant studies. Odds ratio (OR) and 95% confidence interval (CI) were analysed together to assess the strength of the association. Subgroup analysis was mainly performed according to HBeAg. ResultsTwelve studies of 1645 CHB patients met the inclusion criteria and were selected in our meta-analysis. One polymorphism, rs12979860, near to the IFNL3 gene had significant association with the response of CHB patients to IFN-based therapy (OR = 2.35, 95% CI: 1.61–3.42 in allelic model). Another polymorphism, rs8099917, had a similar result (OR = 1.57, 95% CI: 1.03–2.40 in dominant model; and OR = 1.88, 95% CI: 1.21–2.90 in allelic model). When stratified by HBeAg, the antiviral outcome was markedly influenced by both two SNPs in HBeAg positive group (for rs12979860, OR = 1.90, 95% CI: 1.31–2.76 and OR = 2.07, 95% CI: 1.26–3.41 in dominant and allelic models respectively; for rs8099917, OR = 1.67, 95% CI: 1.04–2.67 in dominant model and OR = 1.77, 95% CI: 1.10–2.85 in allelic model). ConclusionWe concluded that two polymorphisms (rs12979860 and rs8099917) of IFNL3 may play a crucial role in the IFN-based treatment of CHB, especially in HBeAg positive group.

What Have We Learned from Studies of IFN-λ Variants and Hepatitis C Virus Infection?

Chronic infection with the hepatitis C virus (HCV) is a major cause of cirrhosis and hepatocellular carcinoma. In 2009, genome-wide association studies (GWAS) strongly linked genetic variants in the interferon lambda (IFN-λ) chromosomal region to HCV clearance. In 2013, discovery of the IFNL4 gene provided a functional explanation for those GWAS findings. The IFNL4-ΔG/TT (rs368234815) variant controls generation of the IFN-λ4 protein. Paradoxically, the IFNL4-TT allele, which abrogates IFN-λ4, associates with higher rates of spontaneous HCV clearance and better response to treatments for HCV infection. The finding that a "knock-out" allele for IFN-λ4 enhances HCV clearance challenges the paradigm of IFNs as antiviral cytokines. Genetic variants in the IFN-λ region have also been associated with hepatic inflammation and fibrosis from various etiologies, however, alleles that are linked with improved HCV clearance associates with worse inflammation and fibrosis. These studies demonstrate that GWAS of infectious diseases may yield important and unexpected biological insights.

Elevated serum levels of adiponectin and interlukin-28B after IFN/RIB therapy in hepatitis C virus-infected patients.

The interleukin 28B (IL28B) genotype is associated with changes of lipid metabolism in patients infected with hepatitis C virus (HCV). The association of steatosis with serum levels of adiponectin in chronic hepatitis C (CHC) patients has also been documented. This study aimed for the evaluation of serum levels of IL28B and adiponectin as well as the association of IL28B SNPs with different clinicopathological parameters in HCV-infected patients. All 142 HCV-infected patients received peg-interferon plus ribavirin. Detection of rs8099917 and rs12979860 IL-28B genotypes was done with specific primers. Serum IL28 and adiponectin levels were measured using commercial ELISA kits. Higher levels of both IL28 and adiponectin were found in patients. In Genotype 3a (G3a) -infected patients, IL28 and adiponectin serum levels were significantly higher than those infected with G1a. A correlation was found between increasing levels of AST and ALT in G3a-infected patients and the decrease in IL28 and adiponectin serum levels, respectively, in contrast to G1a-infected patients. Higher levels of both IL28 and adiponectin were associated with both CT allele of rs12979860 and TT allele of rs8099917 in patients in comparison with corresponding alleles in controls. In contrast to other studies, this study showed higher serum adiponectin levels in HCV-infected patients compared to that in healthy controls. This finding is possibly due to adiponectin resistance caused by down-regulation of adiponectin receptors or tumorigenic effects of adiponectin. Our genotype-based analyses revealed, at least in part, the involvement of the viral factors in the outcome of HCV infection.