Figure 2. Targeting SIY, OVA₂₅₇ or Tyr₃₆₉ eradicated large tumors while targeting mgp100₂₅, hgp100₂₅ or EGP caused initial tumor regression but was followed by relapse.

(A) Cancer cell lines formed progressively growing tumors within one week. TCR-transgenic mice with irrelevant specificity were challenged s.c. with 2×10⁶ cancer cells. MC57-SIY, -mgp100, -mgp100/SIY, -hgp100 and -EGP were injected into OT-I mice; MC57-OVA grew in 2C mice and MC57-TyrHHD grew in AOTA (Tyr-deficient, non-self) and OTA (Tyr-positive, self). Graphs represent single mice in 11 experiments, listed as non-treated controls in Tables 1, S1 and S3. (B) At least 2 weeks after cancer cell injection, when tumors reached about 500 mm³, each mouse was treated once with cognate T cells (treatment between days 13 and 26, depending on tumor size, as indicated by the horizontal bars (H)). Average size of tumors at day of treatment: 2C: 720 mm³, ranging from 448 to 995 mm³; OT-I: 608 mm³, ranging from 440 to 715 mm³; FH: 517 mm³, ranging from 250 to 848 mm³; pmel, targeting mgp100₂₅: 601 mm³, ranging from 325 to 980 mm³; targeting hgp100₂₅: 470 mm³, ranging from 264 to 936 mm³; targeting EGP: 337 mm³, ranging from 180 to 600 mm³. MC57-TyrHHD was grown in OTA (self) and treated with FH T cells (self). The number of rejected tumors per number of tumors treated is indicated. Data are derived from 15 independent experiments, compiled in Tables 1 and S1. See also Figure S2.

* Tumors were isolated and analyzed for antigen expression (see Figure 3).