Fig. 5

Secretions of cytotoxic factors by migrating T cells cocultured with differentially treated RPMECs. RPMECs were divided into three groups: The RPMECs were infected with the live H9N2 virus at 5 MOI(Virus), the RPMECs were inoculated with the inactivated H9N2 virus at 5 MOI ( Particle) and the RPMECs were infected with the live H9N2 virus at 5 MOI and then treated with a PD-L1 specific antibody (Antibody). Then, the activated RPMECs were added to T cells for 8 h. Transmigrated T cells in the bottom chamber were collected and cultured. The levels of IL-2, IFN-γ and granzyme B in T cell supernatants were determined by ELISA kits. Flow cytometry was used to detect the expression of perforin in T cells. The levels of secreted IL-2 (a), IFN-γ (b) and granzyme B (c) and the expression of perforin (d) were determined in T cells cocultured with RPMECs. * Statistical analysis post treatment with the H9N2 virus, the inactivated H9N2 virus particles or the PD-L1 antibody (**P < 0.01, t-test)