Cyclophilin A Interacts with Viral VP4 and Inhibits the Replication of Infectious Bursal Disease Virus

Figure 3

Overexpression of CypA inhibits IBDV replication. (a) The expression of the VP2 and pVP2 proteins was reduced in CypA-overexpressing cells. PCAF-CypA (+) or empty vector (−) was transfected into DF-1 cells for 24 h, and the cells were then infected with the IBDV Gt strain at an MOI of 0.01. At 48 h after infection, the cells were lysed to analyze the effect of the overexpression of CypA on IBDV growth by western blot and to evaluate the expression of IBDV VP2. VP2 (or pVP2) and CypA-Flag were detected with anti-VP2 mAb and anti-Flag mAb, respectively. GAPDH was detected as a loading control. (b) The viral RNA copies were detected through real-time RT-PCR. (c) The virus titers in the culture supernatants of IBDV-infected DF-1 cells were detected as TCID₅₀ per milliliter by the Reed-Muench method. (d) The cell viability and proliferation of DF-1 cells were evaluated using CCK-8 kit. The error bars represent the standard errors of the mean from three independent experiments. The values are shown above the bars. and indicate significant differences.

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