STAT3 is dispensable for the development of IL-17–producing γδ T cells. (A) γδ T-cell–specific disruption of the STAT3 gene in STAT3^flox/floxTie2-Cre mice. Genomic DNA was prepared from purified γδ T cells from the thymi and spleens of STAT3^flox/flox (Cre⁻) and STAT3^flox/floxTie2-Cre (Cre⁺) mice and used for allele-specific PCR analysis. Floxed allele (STAT3 floxed, 350 bp) and disrupted allele (STAT3 Δ, 150 bp) are shown. (B-D) IL-17–producing γδ T cells in STAT3^flox/flox (Cre⁻) and STAT3^flox/floxTie2-Cre (Cre⁺) mice. Single-cell suspensions of fetal (E16) and adult thymocytes (4 weeks old; B-C) or PEC, spleens, and LPLs (4 weeks old; D) from STAT3^flox/flox (flox/flox Cre⁻) and STAT3^flox/floxTie2-Cre (flox/flox Cre⁺) mice were stimulated with PMA and ionomycin and analyzed for intracellular staining for IL-17. (B) Representative dot plots of intracellular staining for IL-17 in fetal (top panels) and adult (bottom panels) thymi are shown after gating on CD3⁺ cells. The number in the top right quadrant indicates the percentage of IL-17⁺ cells in γδTCR⁺ cells. (C-D) Absolute numbers of IL-17⁺ γδ T cells in each organ are shown. Data shown are the means ± SD of 5 mice. N.S. indicates statistically not significant between groups. Data are representative of 3 independent experiments.