IFN-γ production by K^b-CD28-ζ and K^b-CD28[L→G]-ζ RMTCs. GFP-sorted CD8⁺ RMTCs were stimulated 7 days after transduction in the presence of splenocyte feeders on plates coated with 5 μg/mL AF6-88.5 anti-K^b, with conA, or cultured in the absence of stimulation. Stimulation-induced IFN-γ production was measured by Bioplex assay using anti-IFN-γ-coated beads. Data points are means of triplicate samples. Error bars show ± 1 SD; ^*, less than 1 ng/mL.