Figure 6.

Analyses of simultaneous mutagenesis of the identified two residues for PRRSV-2 infection. A TCID₅₀ analyses of the effect of mutated CD163 on PRRSV-2 viral titers. PK-15 cells were transfected with WT or mutated pCD163 constructs. After 24 h, the transfected PK-15 cells were inoculated with PRRSV strain BJ-4 or HN07-1 at a MOI of 1 for 48 h. The viral yields were measured by TCID₅₀ assay in MARC-145 cells. Data represent means ± SEM of three independent experiments. **p < 0.01, ***p < 0.001 for mutant CD163 compared to the WT one. ^#p < 0.05 for simultaneous mutagenesis at position 534 and 561 of CD163 compared to the single-site mutagenesis. B Analyses of PRRSV N protein expression in WT or mutant pCD163-expressed cells. PRRSV N protein expression was tested by IB as described in Figure 5B. C PRRSV infectivity in WT or mutant pCD163-expressed cells. The infectivity was measured by IFA as described in Figure 5C. Data represent means ± SEM of three independent experiments. *p < 0.05.