CXCL8 and infection: Interestingly, the profile of IL-8 secretion detected in THP-1 macrophage-like cells was very similar to those secreted by HT-29 epithelial cells; i.e., EPEC and EHEC pathotypes induced the lower levels of IL-8 secretion (12.3 and 18 ng/ml at 4 h post-infection vs. 19 and 24.6 ng/ml in HT-29 cells).