CD4 and Salmonella Infections: Early after Salmonella infection, IL-17A+IFN-γ- and IL-17A+IFN-γ+ but not IL-17A-IFN-γ+ CD4+ T cells were significantly increased in the cecum of eSPF+SFB compared to eSPF mice (Figures 5A, B) suggesting that colonization with SFB results in the expansion of Th17-related subpopulations of CD4+ T cells but not classical Th1 cells.