CD8 coreceptor enhances the function of class I–restricted, HA-1 TCR–transduced CD4⁺T cells. (A) Intracellular cytokine assay showing IL-2 and IFN-γ production by CD8⁺ T cells (left) and CD4⁺ T cells (right) transduced with HA-1 TCR2 LV (upper panels) or HA-1 TCR2-CD8 coreceptor LV (lower panels) in response to HLA-A2⁺/HA-1⁺ AML or HLA-A2⁺/HA-1^– AML; (B) carboxyfluorescein diacetate succinimidyl ester (CFSE) assay showing proliferation of CD8⁺ T cells (left) and CD4⁺ T cells (right) transduced with HA-1–specific TCR2 LV (upper panels) or HA-1 TCR2-CD8 coreceptor LV (lower panels) in response to HLA-A2⁺/HA-1⁺ primary AML (green and blue), HLA-A2⁺/HA-1^– AML (red), or media control (orange).