Mature thymic NKT and T cells

Invariant Natural killer T (iNKT) cells are a separate lineage of T lymphocytes with innate effector functions. They express an invariant TCR specific for lipids presented by CD1d and their development and effector differentiation rely on a unique gene expression program. We asked whether this program includes microRNAs, small non-coding RNAs that regulate gene expression posttranscriptionally and play key role in the control of cellular differentiation programs. We identified a miRNA profile specific for iNKT cells, which exhibits features of activated/effector T lymphocytes. In this experiment we compared microRNAs of NKT cells versus those of conventional T lymphocytes, both extracted from wild type mouse thymus. To produce the populations we enriched mature thymocytes and then sorted NKT cells and conventional T cells (from one sorting we obtain one “NKT” sample and one “T” sample). We performed the experiment in triplicate; the sample NKT 1 was sorted the same day of the sample T 1, NKT 2 with T 2, NKT 3 with T 3. We used a common reference approach for the 6 samples; as a common reference we produced RNA from total thymocytes, without the enrichment for mature cells and without the sorting; we pooled thymocytes derived from all the thymi used in the study. The aim of the experiment was to demonstrate that NKT cells have a microRNA profile different from that of conventional T cells.