CD4 and infection: To test whether Th2 cells could produce IFNγ during P. chabaudi infection, we FACS-purified CD4+TCRβ+Il4gfp+Ifngyfp–Il17aFP365– Th2 cells from 2-week in vitro cultures (S1 Fig), adoptively transferred them into Rag1–/–mice and infected the recipient mice with P. chabaudi. Cytokine expression in the transferred cells was analyzed in the spleen at day 8 post-infection (Fig 2A).