Modeling host interactions with hepatitis B virus using primary and induced pluripotent stem cell-derived hepatocellular systems

Hepatitis B virus (HBV) chronically infects 400 million people worldwide and is a leading driver of end-stage liver disease and liver cancer. Research into the biology and treatment of HBV requires an in vitro cell-culture system that supports the infection of human hepatocytes, and accurately recapitulates virus–host interactions. Here, we report that micropatterned cocultures of primary human hepatocytes with stromal cells (MPCCs) reliably support productive HBV infection, and infection can be enhanced by blocking elements of the hepatocyte innate immune response associated with the induction of IFN-stimulated genes. MPCCs maintain prolonged, productive infection and represent a facile platform for studying virus–host interactions and for developing antiviral interventions. Hepatocytes obtained from different human donors vary dramatically in their permissiveness to HBV infection, suggesting that factors—such as divergence in genetic susceptibility to infection—may influence infection in vitro. To establish a complementary, renewable system on an isogenic background in which candidate genetics can be interrogated, we show that inducible pluripotent stem cells differentiated into hepatocyte-like cells (iHeps) support HBV infection that can also be enhanced by blocking interferon-stimulated gene induction. Notably, the emergence of the capacity to support HBV transcriptional activity and initial permissiveness for infection are marked by distinct stages of iHep differentiation, suggesting that infection of iHeps can be used both to study HBV, and conversely to assess the degree of iHep differentiation. Our work demonstrates the utility of these infectious systems for studying HBV biology and the virus’ interactions with host hepatocyte genetics and physiology.Skolkovo Institute of Science and Technology (Grant 022423-003)National Institutes of Health (U.S.) (Grant UH2 EB017103)National Institutes of Health (U.S.) (Grant DK085713)National Cancer Institute (U.S.) (Koch Institute Support. Grant P30-CA14051)American Gastroenterological Association (Research Scholar Award)National Institutes of Health (U.S.) (Grant 1K08DK101754)Hertz Foundation (Fellowship)National Science Foundation (U.S.). Graduate Research Fellowship Progra

Involvement of CCR6/CCL20/IL-17 Axis in NSCLC Disease Progression

OBJECTIVES: Autocrine and paracrine chemokine/chemokine receptor-based interactions promote non-small-cell-lung-cancer (NSCLC) carcinogenesis. CCL20/CCR6 interactions are involved in prostatic and colonic malignancy pathogenesis. The expression and function of CCL20/CCR6 and its related Th-17 type immune response in NSCLC is not yet defined. We sought to characterize the role of the CCL20/CCR6/IL-17 axis in NSCLC tumor growth. METHODS: A specialized histopathologist blindly assessed CCL20/CCR6 expression levels in 49 tissue samples of NSCLC patients operated in our department. Results were correlated to disease progression. Colony assays, ERK signaling and chemokine production were measured to assess cancer cell responsiveness to CCL20 and IL-17 stimulation. RESULTS: CCL20 was highly expressed in the majority (38/49, 77.5%) of tumor samples. Only a minority of samples (8/49, 16.5%) showed high CCR6 expression. High CCR6 expression was associated with a shorter disease-free survival (P = 0.008) and conferred a disease stage-independent 4.87-fold increased risk for disease recurrence (P = 0.0076, CI 95% 1.52-15.563). Cancerous cell colony-forming capacity was increased by CCL20 stimulation; this effect was dependent in part on ERK phosphorylation and signaling. IL-17 expression was detected in NSCLC; IL-17 potentiated the production of CCL20 by cancerous cells. CONCLUSION: Our findings suggest that the CCL20/CCR6 axis promotes NSCLC disease progression. CCR6 is identified as a potential new prognostic marker and the CCL20/CCR6/IL-17 axis as a potential new therapeutic target. Larger scale studies are required to consolidate these observations

CRISPR/Cas9 cleavage of viral DNA efficiently suppresses hepatitis B virus

Chronic hepatitis B virus (HBV) infection is prevalent, deadly, and seldom cured due to the persistence of viral episomal DNA (cccDNA) in infected cells. Newly developed genome engineering tools may offer the ability to directly cleave viral DNA, thereby promoting viral clearance. Here, we show that the CRISPR/Cas9 system can specifically target and cleave conserved regions in the HBV genome, resulting in robust suppression of viral gene expression and replication. Upon sustained expression of Cas9 and appropriately chosen guide RNAs, we demonstrate cleavage of cccDNA by Cas9 and a dramatic reduction in both cccDNA and other parameters of viral gene expression and replication. Thus, we show that directly targeting viral episomal DNA is a novel therapeutic approach to control the virus and possibly cure patients.United States. National Institutes of Health (DK085713)National Cancer Institute (U.S.) (P30-CA14051)National Institute of Environmental Health Sciences (P30-ES002109)United States. National Institutes of Health (1K08DK101754

In the Hunt for Therapeutic Targets: Mimicking the Growth, Metastasis, and Stromal Associations of Early-Stage Lung Cancer Using a Novel Orthotopic Animal Model

BackgroundThe existing shortage of animal models that properly mimic the progression of early-stage human lung cancer from a solitary confined tumor to an invasive metastatic disease hinders accurate characterization of key interactions between lung cancer cells and their stroma. We herein describe a novel orthotopic animal model that addresses these concerns and consequently serves as an attractive platform to study tumor–stromal cell interactions under conditions that reflect early-stage lung cancer.MethodsUnlike previous methodologies, we directly injected small numbers of human or murine lung cancer cells into murine's left lung and longitudinally monitored disease progression. Next, we used green fluorescent protein-tagged tumor cells and immuno-fluorescent staining to determine the tumor's microanatomic distribution and to look for tumor-infiltrating immune cells and stromal cells. Finally, we compared chemokine gene expression patterns in the tumor and lung microenvironment.ResultsWe successfully generated a solitary pulmonary nodule surrounded by normal lung parenchyma that grew locally and spread distally over time. Notably, we found that both fibroblasts and leukocytes are recruited to the tumor's margins and that distinct myeloid cell attracting and CCR2-binding chemokines are specifically induced in the tumor microenvironment.ConclusionOur orthotopic lung cancer model closely mimics the pathologic sequence of events that characterizes early-stage human lung cancer propagation. It further introduces new means to monitor tumor–stromal cell interactions and offers unique opportunities to test therapeutic targets under conditions that reflect early-stage lung cancer. We argue that for such purposes our model is superior to lung cancer models that are based either on genetic induction of epithelial transformation or on ectopic transplantation of malignant cells

Regorafenib treatment for patients with hepatocellular carcinoma who progressed on sorafenib-A cost-effectiveness analysis.

BACKGROUND AND AIMS:Hepatocellular carcinoma (HCC) is one of the leading causes of cancer related deaths. Patients with advanced HCC are treated with sorafenib. A recent randomized controlled trial demonstrated a survival benefit for regorafenib treatment in patients with advanced HCC who had progressed on sorafenib. We aimed to evaluate the cost-effectiveness of this approach. METHODS:To evaluate the cost effectiveness of regorafenib, we used a Markov model that incorporates health outcomes, measured by life-years and quality-adjusted life-years (QALYs). Drug costs were based on 2017 discounted prices. Model robustness was validated by probabilistic sensitivity analyses using Monte Carlo simulations. RESULTS:The use of regorafenib results in a gain of 19.76 weeks of life (0.38 Life Years) as compared to placebo. When adjusted for quality of life, using regorafenib produced a gain of 0.25 quality adjusted life years (QALYs). The incremental cost-effectiveness ratio for regorafenib compared with best supportive care was between $201,797 and$268,506 per QALY. CONCLUSION:The modest incremental benefit at a relatively high incremental cost of regorafenib treatment suggests that it is not cost-effective at commonly accepted willingness to pay thresholds

A decision-making model for prediction of a stable disease course in chronic hepatitis B patients

Abstract Patients with chronic hepatitis B (CHB) are regularly monitored for HBV DNA and liver enzymes in order to assess disease progression and the need for antiviral therapy. Identifying patients with a stable course of disease can potentially prolong the intervals between visits, withhold unnecessary tests and save money. Accordingly, we aimed to find predictors for a stable disease course in patients with CHB. 579 patients with CHB, who were followed in a tertiary referral center between January 2004–December 2018, were retrospectively analyzed. Patients with low and steady viral load titer (< 2000 IU/ml) and normal ALT levels (< 40 IU/ml) in 6 consecutive clinic encounters were considered to have a stable course of CHB. A stepwise multivariate logistic regression analysis and a decision tree model were used to identify predictors of a stable disease course. Following exclusion of ineligible patients, a total of 220 patients were included in the final analysis. 64/220 patients had a stable disease course. Patients with a stable disease were older (62.99 ± 12.36 Vs. 54.07 ± 13.64, p < 0.001) with a higher percentage of women (53% vs. 38%) and had lower baseline levels of AST, ALT and viral load (VL). In a multivariate analysis, age (OR 0.94, 95% CI 0.91–0.98), baseline ALT (OR 1.06, 95% CI 1.01–1.1) and VL (OR 1.05 95% CI 1.02–1.08), were significantly associated with a stable disease. In a decision tree model, patients 46–67 years old, with baseline VL < 149 IU/mL and ALT < 40 IU/mL had the best probability (91%) for a stable disease course over 4.4 ± 2.2 years. We conclude that integrating patients’ age with baseline VL and ALT can predict a stable disease course in patients with CHB off treatment

Advances and Challenges in Studying Hepatitis B Virus In Vitro

Hepatitis B virus (HBV) is a small DNA virus that infects the liver. Current anti-HBV drugs efficiently suppress viral replication but do not eradicate the virus due to the persistence of its episomal DNA. Efforts to develop reliable in vitro systems to model HBV infection, an imperative tool for studying HBV biology and its interactions with the host, have been hampered by major limitations at the level of the virus, the host and infection readouts. This review summarizes major milestones in the development of in vitro systems to study HBV. Recent advances in our understanding of HBV biology, such as the discovery of the bile-acid pump sodium-taurocholate cotransporting polypeptide (NTCP) as a receptor for HBV, enabled the establishment of NTCP expressing hepatoma cell lines permissive for HBV infection. Furthermore, advanced tissue engineering techniques facilitate now the establishment of HBV infection systems based on primary human hepatocytes that maintain their phenotype and permissiveness for infection over time. The ability to differentiate inducible pluripotent stem cells into hepatocyte-like cells opens the door for studying HBV in a more isogenic background, as well. Thus, the recent advances in in vitro models for HBV infection holds promise for a better understanding of virus-host interactions and for future development of more definitive anti-viral drugs

Inhibition of pMAPK14 Overcomes Resistance to Sorafenib in Hepatoma Cells with Hepatitis B Virus

Hepatitis B virus (HBV) targets the liver and is a major driver for liver cancer. Clinical data suggest that HBV infection is associated with reduced response to treatment with the multi-kinase inhibitor sorafenib, the first available molecularly targeted anti-hepatocellular carcinoma (HCC) drug. Given that Raf is one of the major targets of sorafenib, we investigated the activation state of the Raf-Mek-Erk pathway in the presence of HBV and in response to sorafenib. Here we show that hepatoma cells with replicating HBV are less susceptible to sorafenib inhibitory effect as compared to cells in which HBV expression is suppressed. However, although HBV replication is associated with increased level of pErk, its blockade only modestly augments sorafenib effect. In contrast, the phosphorylated form of the pro-oncogenic Mitogen-Activated Protein Kinase 14 (pMAPK14), a protein kinase that was recently linked to sorafenib resistance, is induced in sorafenib-treated hepatoma cells in association with HBV X protein expression. Knocking down pMAPK14 results in augmentation of the therapeutic efficacy of sorafenib and largely alleviates resistance to sorafenib in the presence of HBV. Thus, this study suggests that HBV promotes HCC resistance to sorafenib. Combining pMAPK14 inhibitors with sorafenib may be beneficial in patients with HBV-associated HCC