Plasma cytokine and chemokine levels in PRV-infected and control mice. (A) Relative levels of 12 proinflammatory cytokines measured in the plasma of mock-infected (black), PRV-Becker-infected (red), and PRV-Bartha-infected (blue) mice at 82 hpi as determined by ELISA. (B) Concentrations of six proinflammatory chemokines measured in the plasma of these three groups. The concentration is expressed in pg per ml (n = 10 per group). ****, P < 0.0001; ns, not significant. (C) Kinetics of IL-6, G-CSF, Gro-1, and MCP-1 expression in the plasma of mock-infected, PRV-Becker-infected, and PRV-Bartha-infected mice. The concentration is expressed in pg per ml (n = 5 per group). *, P < 0.05; **, P < 0.01; ****, P < 0.0001; ns, not significant.