SLC7A8 intrinsically regulates the effector functions of Th2 cells in vivo. (A) Schematic of the competitive BM chimera experiment: lethally irradiated WT recipients with a 1:1 mixture of Tcrb^−/− and R5^CreSlc7a8^fl/fl (or R5^CreSlc7a8^+/+) BM. 8 wk after reconstitution, the chimeric mice were subjected to HDM-induced airway inflammation. (B) Representative FACS plots showing IL-5⁺CD4⁺ T cells from the lungs of reconstituted mice. (C and D) Frequency of IL-5⁺CD4⁺ T cells and GATA3⁺CD4⁺ T cells from the lungs of Tcrb^−/−+R5^CreSlc7a8^+/+ and Tcrb^−/−+R5^CreSlc7a8^fl/fl constituted mice. (E) Experimental schematic: purified splenic CD4⁺ T cells from R5^CreSlc7a8^fl/fl or R5^CreSlc7a8^+/+ mice were transferred into Rag2^−/− recipients. 8 wk later, mice were challenged intranasally with HDM, and Th2 responses were analyzed. (F) Representative FACS plots showing IL-5⁺ CD4⁺ T cells in the lungs of reconstituted mice. (G and H) Quantification of IL-5⁺ CD4⁺ T cells and GATA3⁺ CD4⁺ T cells in the lungs of mice receiving R5^CreSlc7a8^fl/fl versus R5^CreSlc7a8^+/+ donor cells. (I and J) Frequency of ILC2s in Rag2^−/− mice reconstituted with R5^CreSlc7a8^+/+ and R5^CreSlc7a8^fl/fl CD4⁺ T cells and subjected to HDM challenge. Data are pooled from two individual experiments with n = 3–5 mice per group. Each dot represents an individual mouse. Data are plotted as means ± SEM. Statistics were calculated by unpaired two-tailed Student’s t test. *P < 0.05 and **P < 0.01.