Human resting natural killer (NK) cells, activated NK cells and their secreted small EVs have a specific miRNA repertoire with a distinct pattern of non-templated post-transcriptional modifications

NGS-based assesement of miRNA expression and post-transcriptional modification kinetics in human primary resting and activated natural killer (NK) cells and their released small EVs Overall design: miRNA samples were obtained from either resting NK cells, isolated from five different healthy donors, or activated NK cells. Isolated activated NK cells were cultured for 72 hours in RPMI supplemented with 10% EV-depleted FBS (by ultracentrifugation at 100,000 g for 16 h) for EV accumulation and small EVs were isolated by culture supernatant differential ultracentrifugation for analysis. Libraries were produced and subject to NGS with the Illumina HiSeq 2500 system, and sequencing reads processed to obtain expression estimates of known miRNA molecules described in miRBase (release 21).