Activation of naive intratumoral T calls occurs at multiple T cell precursor frequencies. C57BL/6 bearing established s.c. or i.p. B16-cOVA tumors received 104, 105, or 106 CFSE-labeled Thy1-mismatched OT-I cells. FTY720 treatment was initiated at the time of T cell transfer and continued for the duration of the experiment. 5 d after T cell transfer, tumors and lymphoid organs were harvested and lymphocytes were stained for flow cytometry. Tumor location is indicated to the right of dot plots. Dot plots in A are gated on total lymphocytes. Numbers in dot plots indicate the percentage of OT-I cells out of total lymphocytes in the tumor. Axes on plots are displayed in Logicle scale. Results represent 2 independent experiments, with n = 3–4 mice each for each tumor location and are summarized in B.
