Single-cell RNA sequencing reveals the immunoregulatory roles of PegIFN- in patients with chronic hepatitis B

Background and Aims: Chronic hepatitis B (CHB) is caused by HBV infection and affects the lives of millions of people worldwide by causing liver inflammation, cirrhosis, and liver cancer. Interferon-alpha (IFN-alpha) therapy is a conventional immunotherapy that has been widely used in CHB treatment and achieved promising therapeutic outcomes by activating viral sensors and interferon-stimulated genes (ISGs) suppressed by HBV. However, the longitudinal landscape of immune cells of CHB patients and the effect of IFN-alpha on the immune system are not fully understood. Approach and Results: Here, we applied single-cell RNA sequencing (scRNA-seq) to delineate the transcriptomic landscape of peripheral immune cells in CHB patients before and after PegIFN-alpha therapy. Notably, we identified three CHB-specific cell subsets, pro-inflammatory (Pro-infla) CD14+ monocytes, Pro-infla CD16+ monocytes and IFNG+ CX3CR1(-) NK cells, which highly expressed proinflammatory genes and positively correlated with HBsAg. Furthermore, PegIFN-alpha treatment attenuated percentages of hyperactivated monocytes, increased ratios of long-lived naive/memory T cells and enhanced effector T cell cytotoxicity. Finally, PegIFN-alpha treatment switched the transcriptional profiles of entire immune cells from TNF-driven to IFN-alpha-driven pattern and enhanced innate antiviral response, including virus sensing and antigen presentation. Conclusions: Collectively, our study expands the understanding of the pathological characteristics of CHB and the immunoregulatory roles of PegIFN-alpha, which provides a new powerful reference for the clinical diagnosis and treatment of CHB.