CXCL8 and infection: Quantitative RT-PCR revealed that, while Mabs stimulated il8 expression levels in WT larvae, its expression was severely decreased in the TNFR1-depleted larvae (Fig 8A) and was even further reduced in macrophage-depleted larvae following injection of lipoclodronate (Fig 8A), indicating that macrophages are part of the pathway that triggers IL8 release in response to Mabs infections.