CXCL8 and infection: To determine whether the observed increased in IL-8 production in response to rhMPV-ΔG infection was due to enhanced IL-8 gene transcription, A549 cells were transfected with a construct containing the human IL-8 promoter linked to the luciferase reporter gene [30] and infected with either rhMPV-WT or rhMPV-ΔG.