IL4 and infection: Intracellular staining of CD4+ T lymphocytes revealed that mice reconstituted with CD4+Foxp3- T cells and CD4+Foxp3- T cells + Treg showed augmented production of IFN-γ, IL-17 and IL-4, at weeks 2 and 6 post-infection, when compared with mice receiving Treg cells only (Fig 8C–8E).