Serum vitamin D deficiency is associated with increased risk of γδ T cell exhaustion in HBV‐infected patients

Abstract

Previous studies have demonstrated that T cell exhaustion is associated with poor clearance of Hepatitis B virus (HBV). However, whether the expression of exhaustion markers on innate‐like circulating γδ T cells derived from patients with HBV infection correlates with the serum level of vitamin D is not completely understood. In this study, we found that the frequency of circulating Vδ2+ T cell and serum levels of vitamin 25(OH)D3 were significantly decreased in patients with HBV. And serum 25(OH)D3 levels in HBV‐infected patients were negatively correlated with HBV DNA load and PD‐1 expression on γδ T cells. Interestingly, 1α,25(OH)2D3 alleviated the exhaustion phenotype of Vδ2 T cells in HBV‐infected patients and promoted IFN‐β expression in human cytotoxic Vδ2 T cells in vitro. Collectively, these findings demonstrate that vitamin D plays a pivotal role in reversing γδ T‐cell exhaustion and is highly promising target for ameliorating HBV infection.