Polymorphisms in EGFR and IL28B are associated with spontaneous clearance in an HCV-infected Iranian population

Genetic and pharmacological perturbation of hepatitis-C virus entry

Hepatitis-C virus (HCV) chronically infects 58 million individuals worldwide with variable disease outcome. While a subfraction of individuals exposed to the virus clear the infection, the majority develop chronic infection if untreated. Another subfraction of chronically ill proceeds to severe liver disease. The underlying causes of this interindividual variability include genetic polymorphisms in interferon genes. Here, we review available data on the influence of genetic or pharmacological perturbation of HCV host dependency factors on the clinically observed interindividual differences in disease outcome. We focus on host factors mediating virus entry into human liver cells. We assess available data on genetic variants of the major entry factors scavenger receptor class-B type I, CD81, claudin-1, and occludin as well as pharmacological perturbation of these entry factors. We review cell culture experimental and clinical cohort study data and conclude that entry factor perturbation may contribute to disease outcome of hepatitis C.

Correlation between IL-28 polymorphism and spontaneous clearance in HCV patients: systematic review and meta-analysis

Hepatitis C virus (HCV) is a serious global health issue. Nearly 20% of HCV patients spontaneously clear the virus. While some studies have shown an association of spontaneous clearance (SC) of the virus with interleukin (IL) 28B single-nucleotide polymorphisms (SNPs), others did not show such a relationship. Thus, the purpose of the present study was to investigate the association of IL28B polymorphisms (12979860 SNP) with SC of HCV infection. Upon initial screening of the databases, a total of 545 articles were retrieved, of which 22 studies that met predefined eligibility criteria were entered into the meta-analysis. Odds ratios (ORs) with confidence intervals (95% CI), heterogeneity, publication bias, and sensitivity analysis were assessed. According to the meta-analysis results, a significant association was observed between the rs12979860 SNP and SC of HCV infection. The results indicated that the ORs of SC from hepatitis C virus infection were 2.75 times higher in those with cytokine gene polymorphisms (95% CI, 2.23 to 3.38). Moreover, it was found that the prevalence of rs12979860 CC was 0.33 with 95 CI 0.28-0.38 in genotype 1 and was 0.40 with 95 CI 0.34-0.47 in other genotypes. Our meta-analysis results suggest that IL28B rs12979860 CC is a strong predictor for SC of hepatitis C infection in PEG IFN-a/RBV-treated patients.

Immunometabolic Effect of Cholesterol in Hepatitis C Infection: Implications in Clinical Management and Antiviral Therapy

Hepatitis C virus (HCV) is a lipid-enveloped virion particle that causes infection to the liver, and as part of its life cycle, it disrupts the host lipid metabolic machinery, particularly the cholesterol synthesis pathway. The innate immune response generated by liver resident immune cells is responsible for successful viral eradication. Unfortunately, most patients fail to eliminate HCV and progress to chronic infection. Chronic infection is associated with hepatic fat accumulation and inflammation that triggers fibrosis, cirrhosis, and eventually hepatocellular carcinoma. Despite that the current direct-acting antiviral agents have increased the cure rate of HCV infection, viral genotype and the host genetic background influence both the immune response and lipid metabolism. In this context, recent evidence has shown that cholesterol and its derivatives such as oxysterols might modulate and potentialize the hepatic innate immune response generated against HCV. The impairment of the HCV life cycle modulated by serum cholesterol could be relevant for the clinical management of HCV-infected patients before and after treatment. Alongside, cholesterol levels are modulated either by genetic variations in IL28B, ApoE, and LDLR or by dietary components. Indeed, some nutrients such as unsaturated fatty acids have demonstrated to be effective against HCV replication. Thus, cholesterol modifications may be considered as a new adjuvant strategy for HCV infection therapy by providing a biochemical tool that guides treatment decisions, an improved treatment response and favoring viral clearance. Herein, the mechanisms by which cholesterol contributes to the immune response against HCV infection and how genetic and environmental factors may affect this role are reviewed.

IL-15 and IFN-γ signal through the ERK pathway to inhibit HCV replication, independent of type I IFN signaling

Despite effective new treatments for Hepatitis C virus (HCV) infection, development of drug resistance, safety concerns and cost are remaining challenges. More importantly, there is no vaccine available against hepatitis C infection. Recent data suggest that there is a strong correlation between spontaneous HCV clearance and human NK cell function, particularly IFN-γ production. Further, IL-15 has innate antiviral activity and is also one of the main factors that activates NK cells to produce IFN-γ. To examine whether IL-15 and IFN-γ have direct antiviral activity against HCV, Huh7.5 cells were treated with either IFN-γ or IL-15 prior to HCV infection. Our data demonstrate that IFN-γ and IL-15 block HCV replication in vitro. Additionally, we show that IL-15 and IFN-γ do not induce anti-HCV effects through the type I interferon signaling pathway or nitric oxide (NO) production. Instead, IL-15 and IFN-γ provide protection against HCV via the ERK pathway. Treatment of Huh7.5 cells with a MEK/ERK inhibitor abrogated the anti-HCV effects of IL-15 and IFN-γ and overexpression of ERK1 prevented HCV replication compared to control transfection. Our in vitro data support the hypothesis that early production of IL-15 and activation of NK cells in the liver lead to control of HCV replication.

Germline genetic variants with implications for disease risk and therapeutic outcomes

Genetic testing has multiple clinical applications including disease risk assessment, diagnosis, and pharmacogenomics. Pharmacogenomics can be utilized to predict whether a pharmacologic therapy will be effective or to identify patients at risk for treatment-related toxicity. Although genetic tests are typically ordered for a distinct clinical purpose, the genetic variants that are found may have additional implications for either disease or pharmacology. This review will address multiple examples of germline genetic variants that are informative for both disease and pharmacogenomics. The discussed relationships are diverse. Some of the agents are targeted for the disease-causing genetic variant, while others, although not targeted therapies, have implications for the disease they are used to treat. It is also possible that the disease implications of a genetic variant are unrelated to the pharmacogenomic implications. Some of these examples are considered clinically actionable pharmacogenes, with evidence-based, pharmacologic treatment recommendations, while others are still investigative as areas for additional research. It is important that clinicians are aware of both the disease and pharmacogenomic associations of these germline genetic variants to ensure patients are receiving comprehensive personalized care.

Spontaneous Viral Load Decline and Subsequent Clearance of Chronic Hepatitis C Virus in Postpartum Women Correlates With Favorable Interleukin-28B Gene Allele

BACKGROUND

Postpartum hepatitis C viral (HCV) load decline followed by spontaneous clearance has been previously described. Herein we identify predictors for viral decline in a cohort of HCV-infected postpartum women.

METHODS

Pregnant women at Cairo University were screened for anti-HCV antibodies and HCV RNA, and viremic women were tested for quantitative HCV RNA at 3, 6, 9, and 12 months postpartum. Spontaneous clearance was defined as undetectable viremia twice at least 6-months apart. Associations between viral load and demographic, obstetrical, HCV risk factors, and interleukin-28B gene (IL28B) polymorphism (rs12979860) were assessed.

RESULTS

Of 2514 women, 97 (3.9%) had anti-HCV antibodies, 54 (2.1%) were viremic and of those, 52 (2.1%) agreed to IL28B testing. From pregnancy until 12 months postpartum, IL28B-CC allele women had a significant viral decline (P = .009). After adjusting, the IL28B-CC allele had a near significant difference compared to the CT allele (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.75,1.00; P = .05), but not the TT allele (OR, 0.91; 95% CI, 0.61,1.38; P = .64). All 14/52 (26.9%) women who subsequently cleared were among the 15 with undetectable viremia at 12 months, making that time point a strong predictor of subsequent clearance (sensitivity = 100%, specificity = 97.4%, positive predictive value = 93.3%, negative predictive value = 100%).

CONCLUSIONS

IL28B-CC genotype and 12-month postpartum undetectable viremia were the best predictors for viral decline and subsequent clearance. These 2 predictors should influence clinical decision making.

EGFR rs11506105 and IFNL3 SNPs but not rs8099917 are strongly associated with treatment responses in Iranian patients with chronic hepatitis C

Interferon lambda 3 (IFNL3) and epidermal growth factor receptor (EGFR) single nucleotide polymorphisms (SNPs) may play a key role in the spontaneous clearance of hepatitis C virus (HCV) and treatment responses. The aim of this study was to evaluate the effect of IFNL3 SNPs and EGFR rs11506105 on treatment outcomes in patients with chronic HCV (CHC). IFNL3 SNPs and EGFR rs11506105 were genotyped by PCR-restriction fragment length polymorphism and PCR-sequencing, respectively, in 235 naïve patients with CHC infection. The frequency of rapid virologic response (RVR), complete early virologic response (cEVR) and sustained virologic response (SVR) were 52.3%, 76.2% and 64.7% respectively. The results of this study showed that RVR was associated with ALT (P=0.015), AST (P=0.020), IFNL3 rs12979860 (CC) (P=0.043), rs12980275 (AA) (P=1 × 10-4), and EGFR rs11506105 (AA) (P=0.010), and IFNL3 rs12979860 (CC) (P=0.048), rs12980275 (AA) (P=0.022), and EGFR rs11506105 (AA) (P=0.006) were correlated with cEVR. HCV genotype (P=0.007), IFNL3 rs12979860 (CC) (P=0.023), IFNL3 rs12980275 (AA) (P=1 × 10-4), EGFR rs11506105 (AA) (P=0.005), RVR (P=1 × 10-4), and cEVR (P=0.003) were significant predictors for SVR. These results, for the first time, revealed that beside IFNL3 SNPs, EGFR rs11506105 is strongly associated with RVR, cEVR and SVR. EGFR rs11506105 besides IFNL3 SNPs could predict treatment responses in CHC patients.

The Role of ErbB Receptors in Infection

Members of the epidermal growth factor receptor family (ErbB family) possess a wide distribution and diverse functions ranging from cellular growth to migration and apoptosis. Though highly implicated in a variety of cancers, their involvement in infectious disease is less recognised. A growing body of evidence now highlights the importance of the ErbB family in a variety of infections. Their role as growth factor receptors, along with other characteristics, such as surface expression and continuous intracellular trafficking, make this receptor family ideally placed for exploitation by pathogens. Herein, we review our current understanding of the role of the ErbB family in the context of infectious disease, exploring the mechanisms that govern pathogen exploitation of this system.

A wide and diverse variety of microbes have each evolved distinct mechanisms to exploit ErbB receptors, highlighting this receptor kinase family as a critical factor in initiation and maintenance of pathogen infections.

ErbB family members are utilised by pathogens attempting to gain cellular entry, subvert immune responses, and manipulate the cell cycle of infected host cells. These events support and are necessary for pathogen persistence.

Pathogen-mediated ErbB-exploitation may contribute to cellular transformation and oncogenesis in a variety of cancers.

The use of existing FDA-approved drugs that target ErbB receptors and associated signalling components may offer potential future therapies against infection.