Immunomodulation and RNA interference alter hepatitis B virus–specific CD8 T‐cell recognition of infected HepG2‐NTCP

BACKGROUND & AIMS CD8 T cells are essential in controlling Hepatitis B virus (HBV) infection. Viral control is dependent on efficient recognition of HBV-infected hepatocytes by CD8 T cells, which can induce direct lysis of infected hepatocytes. In addition, CD8 T cells produce IFN-γ, which mediates non-cytopathic viral clearance. Innate immunomodulators and HBV-targeted RNA interference (RNAi) are being developed to treat chronic hepatitis B, but may modify HBV antigen presentation and impact CD8 T cell recognition, in addition to their primary mechanisms of action. APPROACH & RESULTS HBV infected HepG2-NTCP were treated with tenofovir disoproxil fumarate (TDF), Toll-like receptor (TLR) 7/8 agonists, TLR7/8 conditioned media (CM) collected from immune cells, or RNAi using short-interfering RNAs (siRNAs). The effect of these treatments on antigen presentation was measured through co-culture with CD8 T cells recognizing HLA-A0201 restricted epitopes, HBc18-27 or HBs183-191. Cytokine profiles of TLR7/8 CM was measured using cytometric bead array. TDF reduced viral replication, but not CD8 T cell recognition of infected cells. Direct exposure of infected HepG2-NTCP to TLR7/8 agonists had no impact on T cell recognition. Exposure of infected HepG2-NTCP to TLR7/8 CM enhanced HBV-specific CD8 T cell recognition through type 1 interferon (IFN) and IFN-γ dependent mechanisms. RNAi rapidly suppressed HBV DNA, HBV Core antigen (HBcAg), and HBV S antigen (HBsAg) expression, impairing recognition by HBV-specific CD8 T cells. CONCLUSIONS Immunomodulation, and RNAi, but not nucleos(t)ide analogues, alter recognition of infected HepG2-NTCP by HBV-specific CD8 T cells. Understanding these changes will inform combination treatments for CHB.