TNF and infection: The addition of neutrophils to the model, creating a neutrophil-epithelial co-culture in the absence of any infection, resulted in a significant secretion of interferon gamma (IFNγ) (p<0.01) and IL-10 (p<0.01) at the apical surface with notable, but not statistically significant, increases in tumor necrosis factor alpha (TNFα) (Figure 1B).