Measuring T-cell-Mediated Cytotoxicity on Hepatitis B and D Virus-Infected Cells

An xCELLigence RTCA system (ACEA Biosciences, San Diego, CA, USA) was used to determine the impact of HDV innate immune recognition on cell viability. HepG2-NTCP cells were co-cultured with genetically modified HBV-specific T-cells [25 (link),26 (link)] and T-cell induced antigen-specific killing rates were measured. Therefore, HepG2-NTCP and HepG2-NTCP MDA5 ko cells were differentiated for 14 days. Differentiated cells were co-infected with either HBV and HDV or only HBV and infection was established for seven days. Afterwards, infected cells were seeded at a density of 5 × 10⁴ cells/well on collagenized xCELLigence 96-well plates and rested for two more days prior to start of co-culture. T-cells were added to seeded cells in different effector (T-cell) to target (HepG2-NTCP cell) ratios (1:1, 1:3, 1:9). Cell viability was determined as cell index and normalized to the start of co-culture.