Figure 1. Expression and recognition of K^d/LLO_91–99 SCTs by CD8⁺ T cells.

(A) Cell surface expression of K^d/LLO_91–99 SCTs. 293T cells were transfected with K^d/LLO_91–99 SCT DNA and stained with anti-K^d mAb (SF1-1.1.1, solid line). A shaded histogram shows staining of untransfected cells. (B) Activation of hybridomas specific for LLO 91–99/K^d by K^d/LLO_91–99 SCT-expressing cells. Transfected 293T cells were incubated with T hybridomas at the ratios of 1:1 for 24 hours and the amounts of IL-2 in the culture supernatant were measured by ELISA. For controls, P815 cells that express endogenous K^d were incubated with hybridomas with or without 1µg/mL of LLO 91–99 peptide.