Figure 4. Role of Trm in the control of orthotopic tumours.

(a) Mice were i.n. immunized or not with STxB-E7 and αGalCer at D0 followed by a boost at D14 with STxB-E7. TC1 cells were grafted at D21. One day before the tumour challenge, the mice were started to be treated or not daily with FTY720 and monitored for survival. (b) Mice were i.n. immunized or not with STxB-E7 and αGalCer at D0 followed by a boost at D14 with STxB-E7. One month later, mice were grafted with TC1 cells in the tongue. Survival was monitored and represented by a Kaplan–Meier curve. Experiments were repeated at least three times. ****P<0,0001. (c,d) Mice were immunized as in a. Trm (c) and effector CD8⁺T cells (d) were then measured in the whole tongue 30 days after the boost without TC1 challenge (D44 after priming) for Trm or 30 days after a TC1 submucosae graft at D21 (day 51 after priming) or 30 days after the third TC1 challenge at day 111 (D141 after priming) for both Trm and effector CD8⁺T cells. One of two representative experiments is shown. (e) Mice were not immunized and grafted with TC1 cells at day 21 or day 51 or day 111 (red filled square). Another (green filled triangle) group of mice were (black filled nabla) immunized with STxB-E7 at D0 and D14 and grafted with TC1 at D21, D51 and D111. FTY720 was injected i.p. from (blue filled circle) D110 (one day before the third tumour challenge) until the end of the experiment. Survival was monitored. Experiments were reproduced three times. Statistical analysis for (a,b,e) used Log-rank test and for (c,d) non-parametric Mann–Whitney test. *****P<0.00001, ****P<0.0001, **P<0.01. Error bars indicates s.e.m. NS, not significant.