New miRNA signatures herald human NK cell subsets at different stages of differentiation: involvement of miR-146a-5p in the regulation of KIR expression

ABSTRACT: Natural killer cells are cytotoxic innate lymphoid cells that play an important role for early host defenses against infectious pathogens and surveillance against tumor growth and metastasis. In humans, NK cells may be divided in various subsets on the basis of the relative expression of the CD56 molecule and of the low-affinity FcγRIIIA CD16. In particular, the two main NK cell subsets are represented by the CD56bright CD16-/dull and the CD56dull CD16bright NK cells. A number of experimental evidences indicate that CD56bright and CD56dull NK cells represent different maturative stages of the NK cell developmental pathway. In an effort to identify NK cell miRNA signatures that may contribute to the NK cell-specific maturation program, we determined the miRNA profile of human NK cell subpopulations derived from peripheral blood samples of healthy donors. We identified multiple miRNAs that are differentially expressed in CD56bright CD16- and CD56dull CD16bright NK cells. Among these, we found a few miRNAs with a consistent differential expression in the two NK cell subsets, and with an intermediate expression in the CD56brightCD16dull NK cell subset, representing a transitional step of maturation of NK cells. Our data have been confirmed by both quantitative real-time PCR and multivariate analysis. These analyses allowed us to establish the existence of a miRNA signature able to discriminate the two main NK cell subsets, regardless of their surface phenotype. In addition, by analyzing the putative targets of representative miRNAs we show that miR-146a-5p, that displays a significant up-regulation in CD56bright as compared to CD56dull NK cells, may be involved in the regulation of killer Ig-like receptor (KIR) expression. These findings may contribute to a better understanding of the physiologic significance of miRNAs in the regulation of NK cell development/function. In addition, our results suggest that miR-146a-5p targeting, resulting in KIR down-regulation, may be exploited as a tool to generate/increment the effect of NK KIR-mismatching against HLA class I+ tumor cells and thus to improve the NK-mediated anti-tumor activity.

ORGANISM(S): Homo sapiens

PROVIDER: GSE116743 | GEO | 2018/11/06

REPOSITORIES: GEO