miR-146a expression correlates with a memory phenotype and exposure to IL-2 in naïve T cells. Naïve CD8+ T cells were stimulated with anti-CD3/28 magnetic beads and cultured in the presence of either 10 ng/ml IL-2 or IL-7. At 28 days post stimulation cells were harvested and either subjected to FACS analysis to assess expression levels of T cell memory markers CD45RO and CCR7 or assessed for miR-146a expression levels by RT-PCR. (A) Graph showing % positive cells for CCR7+ and (B) CCR7 + CD45RO- as assessed by FACS analysis. Each data point represents one donor, n = 4. Statistical significance was analysed using GraphPad Prism software using the Student’s t-test. (C) RT-PCR relative expression data for miR-146a at day 28 post stimulation for the cells phenotyped in panels A and B. Each data point represents the average of triplicates from an individual donor, n = 4. Statistical significance was analysed using GraphPad Prism software on non-normalised expression data using the Student’s t-test. Results with a p value <0.05 were considered to be statistically significant. * = p <0.05; ** = p <0.01. (D) Naïve T cells were stimulated as in panel C in the presence of 10 ng/ml IL-2. At various time points post-stimulation cells were harvested and miR-146a expression levels were assessed by RT-PCR. (E) As (D) but cells were grown in the presence of 10 ng/ml IL-7. Each data point represents the average of triplicates from an individual donor. The data in panels D and E represent collated data from 4 donors (5 donors for IL-7) each tested at between 1 – 4 time points.