HBV therapeutic vaccines and cccDNA inhibitors - emergence of a cure

An Overview of the Current Hepatitis B Treatment Strategies after Liver Transplantation

Currently, liver transplantation (LT) is considered as the only option for the treatment of patients with various causes of liver failure, including patients with chronic hepatitis B virus (HBV) infections. Overall, patients with HBV who undergo LT are at increased risk of hepatitis B infection recurrence. Although the current knowledge regarding the pathophysiology of this infection has been dramatically increased over the past few decades, it is still considered a complex disease process with varying degrees of clinical characteristics and changing patterns over time. There are various treatment strategies for preventing HBV recurrence in the LT setting. Generally, these regimens include oral nucleoside/ nucleotide analogues (NAs), hepatitis B immune globulin (HBIG), and vaccines or the combination of these drugs. The treatment strategy of choice should be based on cost-effectiveness, along with other patients underlying conditions. In this case, studies indicate that potent NAs are more cost-effective than HBIG in most case scenarios. In this article, we aimed to review the general medications used in the prophylaxis of the recurrence of HBV infection after LT.

Enhanced antiviral benefit of combination therapy with anti-HBV and anti-PD1 gRNA/cas9 produces a synergistic antiviral effect in HBV infection

Targeted therapy for patients with hepatitis B virus (HBV) infection can lead to objective responses, although response times may be short. At the same time, the response rate to programmed cell death-1 (PD-1) treatment was more durable. It is speculated that HBV targeted therapy can synergistically enhance the antitumor activity with PD-1 blockade. To test this hypothesis, we evaluated the effect of crispr-cas9 on HBV and PD-1 in vitro and in vivo. We found that HBV targeting gRNA/cas9 induced a decrease in the expression of HBsAg, while the PD-1 gene could be knocked out by electroporation targeting gRNA / cas9 by polymerase chain reaction. In HBV transgenic mice, the immunophenotype and cytokine expression of human dendritic cells (DCS) were detected by crispr-cas9 system stimulation, flow cytometry and polymerase chain reaction. These results indicate that gRNA/cas9 treatment upregulates the expression of CD80, CD83 and CD86, and significantly increases the mRNA levels of IL-6, IL-12, IL-23 and tumor necrosis factor alpha. The combination of anti HBV and anti PD-1 therapy can inhibit HBV expression and significantly improve the survival of HBV transgenic mice. In addition, the combination therapy increased the production of interferon by T cells, and then enhanced the expression of Th1 related immunostimulatory genes, thereby reducing the transcription of regulatory / inhibitory immune genes. In general, this response can reshape the tumor microenvironment from immunosuppression to immune stimulation. Finally, anti HBV therapy can induce the expression of interferon dependent programmed cell death ligand-1 in HBV transgenic mice in vivo. To sum up, these results demonstrate that the combination of HBV targeted therapy and PD-1 immune checkpoint block has a strong synergistic effect, thus supporting the transformation potential of this combined therapy strategy in clinical treatment of HBV infection.

Detection of HBV Covalently Closed Circular DNA

Chronic hepatitis B virus (HBV) infection affects approximately 240 million people worldwide and remains a serious public health concern because its complete cure is impossible with current treatments. Covalently closed circular DNA (cccDNA) in the nucleus of infected cells cannot be eliminated by present therapeutics and may result in persistence and relapse. Drug development targeting cccDNA formation and maintenance is hindered by the lack of efficient cccDNA models and reliable cccDNA detection methods. Southern blotting is regarded as the gold standard for quantitative cccDNA detection, but it is complicated and not suitable for high-throughput drug screening, so more sensitive and simple methods, including polymerase chain reaction (PCR)-based methods, Invader assays, in situ hybridization and surrogates, have been developed for cccDNA detection. However, most methods are not reliable enough, and there are no unified standards for these approaches. This review will summarize available methods for cccDNA detection. It is hoped that more robust methods for cccDNA monitoring will be developed and that standard operation procedures for routine cccDNA detection in scientific research and clinical monitoring will be established.