CXCL8 and infection: Twenty-four hours after infection, we assessed inflammatory responses of the macrophages by measuring the levels of cytokines, including granulocyte/macrophage colony-stimulating factor (GM-CSF), IFN-γ, interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10 and TNF-α, secreted in the culture supernatant.