FIG 5.

Human STING agonist diABZI can efficiently block HCoV-OC43 infection in human lung tissue slices. Human lung tissue slices were pretreated with DMSO or 1 μM human STING agonist diABZI for 3 h in 200 μl keratinocyte serum-free medium. The slices were treated with HCoV-OC43 virions diluted in 1 ml keratinocyte serum-free medium at 0.5 × 10e6 PFU/ml. The slices were incubated at 33°C in 5% CO₂. At 6 days postinfection, slices were immunostained using the antibody against the HCoV-OC43 N protein (OC43 N) and counterstained with DAPI. OC43 N⁺ bright red dots in the tissues are infected cells. Bar: 50 μm.