Figure 2.

Aldesleukin increases primary human CD8⁺ T and NK cell cytotoxicity and adhesion marker expression. (A) Gating strategy for surface marker analysis and determination of fractions of viable, early apoptotic and late apoptotic cells. Representative plots from one CD8⁺ T cell monoculture experiment are shown. (B-G) Primary human CD8⁺ T cells were stimulated for 5 d with aldesleukin or activation controls (act I, CD3/CD28 + rhIL-2 activation; act II, PHA-L + rhIL-2 activation). (H-M) Primary human NK cells were stimulated for 2 d with aldesleukin or activation controls (act I, CD2/CD335 + rhIL-2 activation; act II, CD2/CD335 + rhIL-15/21 activation). Per stimulation point, 0.1 x 10⁶ cells were stimulated. To quantify surface marker expression, cells were analysed by flow cytometry and the mean fluorescence intensity was related to the vehicle control. The fractions of viable (Zombie Violet^-/Annexin V^-), early apoptotic (Zombie Violet^-/Annexin V⁺), and late apoptotic (Zombie Violet⁺/Annexin V⁺) cells were determined as described in the methods section. Number of biological replicates: N = 3 (G); N = 4 (D, M); N = 5 (E, J); N = 6 (B, C, F). N = 7 (H, I, K); N = 9 (L). In some cases, there are fewer biological replicates for the activation controls. One technical replicate was performed except for CFSE dilution assays. Data are shown as mean ± SEM. For statistical analysis, one-way ANOVA with Dunnett´s correction (D, E, F, I, K, L), Kruskal Wallis test with Dunn´s multiple comparison test (B, C, H, J) or two-way ANOVA with Dunnett´s correction (G, M), was used. * p < 0.05, ** p < 0.01, *** p < 0.001 and **** p < 0.0001 indicate significant differences between aldesleukin-treated or activated and vehicle-treated samples. CFSE, Carboxyfluorescein succinimidyl ester; ICAM-1, intercellular adhesion molecule 1; TRAIL, Tumor Necrosis Factor Related Apoptosis Inducing Ligand.