IL17A and infection: In order to model the effects of Th1- and Th17-dominated responses on the capacity of these phagocyte stepwise cocultures to control bacterial infection, macrophages that were untreated or pretreated with IFN-γ or IL-17A for 24 h were infected with P. aeruginosa (multiplicity of infection [MOI] = 0.5) for 2 h, at which time half of the cultures were collected for analysis and neutrophils were added as described above.