CCNA1-specific T cells show cytotoxicity against HLA-matched, CCNA1⁺tumor cell lines. (A) Donor 2’s cell line showed high specific lysis toward U266 (HLA-B7⁺ and CCNA1+) in a 4-hour Cr⁵¹-release assay, compared with targets that express either HLA-B7 or CCNA1 alone. (B) Similarly, donor 2’s cell line produced IFN-γ and granzyme B, as assessed by ELISpot, following incubation with the U266 cell line, but not when U266 was cultured alone. (C) Further examples of CCNA1-specifc T cells from donors with characterized HLA-restricted CCNA1 reactivity, showing specific lysis toward CCNA1-expressing leukemic cell lines matched at the relevant HLA allele, with minimal activity against targets that were HLA mismatched and/or CCNA1 negative. (D) CCNA1 expression of 2 primary AML cell lines (left; CCNA1, shaded curve; no primary control, unshaded curve) with HLA-A2 status of patients, and specific lysis of patient 1’s AML blasts (right).