Figure 5From: Engineered artificial antigen presenting cells facilitate direct and efficient expansion of tumor infiltrating lymphocytesYoung TILs with favorable cell subset composition can be expanded directly from fresh tumor digests using aAPCs. (a) Fresh ovarian cancer digests (PRE-EXP) are comprised by a heterogenous mix of EpCAM+ tumor cells and CD45+ leukocytes, containing CD14+ monocytes and CD3+ T cells; aAPC expanded digests (POST-EXP) contain only CD45+ CD3+ T cells. Lower dot plots are CD45+ gated. (b) 106 total tumor digest cells were stimulated with 106 aAPC loaded with anti-CD3 and anti-CD28 agonist antibody in CM containing 100 IU/mL IL-2, or cultured in 600 IU/mL IL-2 alone. Mean viable cell counts ± SEM are shown (n = 7). (c) Fold expansion of CD3+ TILs. Calculated viable absolute T cell numbers are shown (Total T cell number times % viable CD3+). (d) Ratio of CD4 + TILs to CD8+ TILs pre- and post-expansion with either aAPC or IL-2 alone; (e) percentage of CD3+ TILs expressing CD27; (f) or CD28; (g) percentage of CD4+ CD3+ TILs expressing FOXP3. Values in (d-g) represent the mean expression of the indicated molecule by 4 independently expanded TILs. (h) TILs expanded directly from enzyme-digested tumor specimens using KT64/BBL aAPC demonstrated autologous tumor reactivity. 105 aAPC-expanded TILs or 105 TILs outgrown in 600 IU/mL of IL-2 were co-cultured overnight with 105 autologous tumor cells or not stimulated (none). Anti-CD3/28 bead stimulation was applied as positive control. Mean concentration of IFN-g (pg/mL ± SEM) detected in supernatants from paired aAPC- and IL-2-expanded TIL cultures from 4 independent ovarian cancer specimens with anti-tumor reactivity is shown.Back to article page