Fig. 4.

Detection of TILs in the matched M202 tumor. (A) Total tumor cells were stained for CD45 and MART-1 tetramer and analyzed by flow cytometry to detect TILs. The data indicate percentage of CD45⁺ cells that are MART-1 TCR-positive by tetramer staining. The levels of CD45⁺ cells in these tumors ranged from 0.4–0.5% of total cells. Shown are individual mice from one representative experiment. (B) Mice were imaged using an sr39tk-specific probe 6 wk after tumor injection to detect infiltration of transgenic T cells into M202 and M207 tumors. Tumors from the same mouse are matched with the same symbol. Shown are six mice from one representative experiment. Statistical significance was determined by a paired Student‘s t test with significant values set at P < 0.05. %ID/g, injected dose per gram of body weight.