CXCL8 and infection: The concentrations of IL-1β and IL-8 were significantly (P = 0.045 for IL-1β at day 16; P = 0.0257 and P = 0.010 for IL-8 at day 12 and 20 respectively) higher in wild type-infected compared with ∆Vpr-infected culture at infection phase (Figure 2A).