Effects of tenofovir disoproxil fumarate on intrahepatic viral burden and liver immune microenvironment in patients with chronic hepatitis B

Abstract

Background The impact of nucleos(t)ide analogues on intrahepatic viral burden and immune microenvironment in patients with chronic hepatitis B (CHB) is not clear. Objective We aimed to characterise the effects of tenofovir disoproxil fumarate (TDF) on intrahepatic viral burden and the liver immune microenvironment in patients with CHB. Design Core liver biopsies were collected at baseline and year 3 from patients with CHB with minimally raised serum alanine aminotransferase in a double-blind placebo-controlled trial ([NCT01522625][1]). Paired biopsies were analysed by RNA-sequencing (n=119 pairs), a custom multiplex immunofluorescence assay (n=30 pairs), and HBV-targeted long-read DNA sequencing (n=49 pairs). Results Both non-integrated and integrated HBV DNA were present in all patients at baseline, with >65% having interchromosomal translocations. Treatment significantly reduced the frequency of HBV core+ hepatocytes and intrahepatic (integrated and non-integrated) HBV DNA, but had no effect on HBsAg+ hepatocytes. Clonally expanded integrations were enriched for HBsAg coding regions and showed dysregulation of nearby genes. At baseline, there was significant enrichment of intrahepatic CD8+ T cell proximity to HBV core+ hepatocytes, but not to HBsAg+ cells. The densities of T cells and B cells were significantly reduced by TDF. Transcriptomic analyses found TDF induced widespread downregulation of immune-related genes including inhibitory and regulatory genes. Conclusion TDF significantly reduced intrahepatic integrated and non-integrated HBV DNA, exerting disparate effects on HBV core+ and HBsAg+ cells and on different immune cell subsets. Our data suggest there may be differential cytotoxic T cell-mediated killing of HBV core+ versus HBsAg+ hepatocytes, providing insights for HBV cure strategies. Data are available upon reasonable request. Data collected for this study, including deidentified individual participant data and data dictionaries defining fields in the datasets, will be made available on request to with qualified external researchers based on submitted curriculum vitae and reflecting non conflict of interest as well as laws and regulations regarding patient privacy. Approval of such requests is dependent on the nature of the request, the merit of the research proposed, the availability of the data and the intended use of the data. Data requests should be sent to the corresponding author at holdenhsu@gmail.com. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01522625&atom=%2Fgutjnl%2Fearly%2F2024%2F10%2F08%2Fgutjnl-2024-332526.atom