Real-time dependency of T-cell mediated cytotoxicity on T cell density.

IGR-Pub lung cancer cells were co-cultured on-chip with autologous T cells at indicated E:T ratios. A. Time-course quantifications of the apoptosis rate, calculated in 4 h-time-intervals (T_LAG = 4 h), for a total duration of 48 h. B. Survival curves of cancer cells within the ToC at 1-hr time resolution. For each t_i the % of surviving cells, calculated with respect to the initial number of living cells, is the average of 3 hours, centered on t_i, to smoothen the fluctuations. The graphs show the means of 3 measurements on 3 view fields from the same experiment (+/- SEM). For statistical analysis, the measurements for each of the 4 conditions were assembled regardless of the time variable (n = 36 per condition). The different E:T ratio conditions were compared to the control condition of cancer cells only. In panel A, the data passed the Shapiro-Wilk normality test, therefore the unpaired t test was applied. In panel B, the data did not pass the Shapiro-Wilk normality test, therefore the non-parametric Mann-Whitney test was applied. **** indicates p<0.0001, ** indicates p<0.001, * indicates p<0.05 and ns indicates not significant.