CD4⁺ RTEs are biased to Th2 effector responses in vivo. Purified OT-II TCR Tg CD4⁺CD45.1⁺ RTEs and MN T cells were transferred into B6 hosts and immunized subcutaneously 1 day later with OVA and papain. Cells from draining inguinal LNs were analyzed for cytokine production on day 4. (A) Representative flow cytometry plots show accumulation of CD4⁺ RTEs (left) and MN T cells (right) in unimmunized and immunized hosts. Gated cells are > 99% Vα2⁺Vβ5⁺. (B) Representative plot showing IL-4 production by transferred Vα2⁺Vβ5⁺ OT-II RTE (left) and MN (right) T cells after a 5-hour restimulation in the presence (+OVAp) or absence (-OVAp) of OVA_323-339 peptide. Numbers represent percentage of cells in that gate. (C) Percentage of IL-4⁺ OT-II CD4⁺ T cells and MFI of IL-4⁺ cells. Compiled data are presented as mean ± SEM for 4 individually analyzed mice per group. *P < .05. (D) Transferred OT-II CD4⁺ RTEs and MN T cells were sort purified and restimulated with plate-bound anti-CD3 plus anti-CD28. Supernatants were harvested after 72 hours and assayed for IL-5 and IL-13 by ELISA. Data are presented as mean ± SD of triplicate wells. *P < .05, **P < .005.