SOCS3^−/ΔLck T cells are hyperresponsive to T-cell receptor ligation after G-CSF mobilization. (A) Size and cell subset composition of spleens from G-CSF–treated WT or SOCS3^−/ΔLck mice. Data are representative of 3 similar experiments (n = 3 animals/group). DN indicates double negative. (B) Splenocytes from G-CSF–treated WT or SOCS3^−/ΔLck mice were cultured in the presence of soluble CD3, and proliferative responses were assessed by [³H] thymidine incorporation. (C) Supernatants from CD3 cultures were harvested at 72 hours and assayed for cytokines by cytometric bead array or enzyme-linked immunoabsorbent assay (IL-17A, IL-17F, and TGFβ). Data are pooled from 2 independent experiments, n = 4-6 animals/group. *P < .05; ** P < .01. (D) IFNγ secretion by purified CFSE-labeled T cells at the times indicated after stimulation with plate-bound CD3 and CD28. Data are representative of 2 experiments.