The full length of GP5 was required for IL-10 induction. (a) Schematic representation of truncated GP5 (numbers indicate the amino acids positions). The black squares represent the translation termination. (b) PAMs were transfected with the truncated GP5 expression plasmids (2 μg) or empty vector. Cells were harvested at 24 h post transfection. Total RNA isolated from cells was reverse transcribed and real-time PCR was performed to detect porcine IL-10 mRNA. Results are shown as means ± SD of three independent transfections. *Significant difference (P < 0.05) from wild-type GP5 using Student’s t-test.