TNF and infection: We examined whether soluble factors secreted from C. jejuni-infected HT-29 cells (human colorectal adenocarcinoma cells that express characteristics of mature intestinal cells) at 10 and 50 multiplicities of infection (MOI) influence RAW 264.7 macrophage activity, including nitric oxide (NO) production, migration, phagocytosis, bacterial killing, and the expression of cytokines (IL-6, IL-1β, TNF-α) and the chemokine CCL2.