Figure 6. Induction of CTL differentiation by killer-specific secretory protein of 37Kd (Ksp37). Splenic T cell from C57BL/6 mice (H-2^b) were obtained as described in (PNAS Okada et al. 1981), and cultured with uv-treated BALB/c (H-2^d) spleen cells (Mitomycin C treated) in the presence of 100ng/ml rKsp37 and/or an anti-Ksp37 antibody for 5 d. CTL activity against P815 tumor cells (H-2^d) was assessed by using ⁵¹Cr assay.