AntimicroRNA-31 (anti-miR-31) inhibits the previously observed miR-31 effects in purified T cells of healthy donors. (A) Purified CD4⁺ T cells of healthy donors (n = 4) were incubated with Accell anti-miR-31-5p (open bars) or a DY-547-labeled scrambled control for 72 h with (+) and without (−) stimulation with anti-CD3/CD28 Dynabeads. Successful transfection was confirmed by quantitative polymerase chain reaction (left panel) as well as by flow cytometry (right panel). Data are means ± SD. **P < 0.0001 in paired Student’s t test. Histogram is representative of n = 3 individual experiments performed in duplicates. (B, C) Relative mRNA levels of the miR-31 target genes nuclear factor-kappa B–inducing kinase (NIK), factor-inhibiting hypoxia-inducible factor-1α (FIH), and SH2D1A (B) as well as of the T_H1/T_H2 cytokines interferon (IFN)-γ, interleukin (IL)-2, and IL-4 (C) were quantified in CD4⁺ T cells of healthy donors after 72 h of incubation with Accell anti-miR-31-5 (open bars) or scrambled control in the absence (in case of target genes) or presence (in case of cytokines) of anti-CD3/CD28 Dynabeads. Data are means ± SD of n = 3 to 4 independent experiments. NIK: *P = 0.0061; FIH: *P = 0.0465; SH2D1A: *P = 0.0024; IFN-γ: not significant (ns) P = 0.1136; IL-2: *P < 0.0001; IL-4: *P = 0.0113 in paired Student’s t test.