FIG 5.

Overexpression of Trx2 inhibits the replication of CSFV N37D mutant more efficiently than that of wt CSFV. PK-15 cells were transduced with Lenti-EGFP-Trx2 or Lenti-EGFP for 48 h followed by infection with the CSFV Shimen strain or N37D mutant. (A) Ectopic expression of EGFP-Trx2 in PK-15 cells. Flow cytometry assay was used to detect the cellular expression of EGFP in PK-EGFP-Trx2, PK-EGFP, or PK-15 cells. (B) Expression of the CSFV N^pro protein in the stable cell line overexpressing Trx2. Western blotting of the N^pro expression in the cell lysate collected at the indicated time points after infection. β-Tubulin was used as a loading control. The experiment was carried out in three replicates. The quantification analysis of N^pro expression in the cell lysate was carried out using the Odyssey application software version 3.0. (C) Viral genome copies of Trx2-overexpressing cells infected with CSFV Shimen or N37D mutant. CSFV genome copy numbers in Trx2-overexpressing cells were assessed using a quantitative RT-PCR assay. (D) Infectious progeny virus titers in the supernatant of Trx2-overexpressing cells infected with CSFV Shimen or N37D mutant. Virus titers in the supernatant collected at 48 and 72 hpi were determined and expressed as 50% tissue culture infective doses (TCID₅₀)/ml. Error bars represent the standard deviations of the means from three independent experiments. P values are indicated above the bars.