English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Variegated expression of killer Ig-like receptors (KIR) in human NK cells is a stochastic process exclusive to subsets of mature NK cells and CD8 + T cells. Allele-specific KIR expression is maintained by DNA methylation within the proximal promoter regions. Because KIR genes are densely methylated in NK cell progenitors, there is an implied stage of human NK cell development in which DNA demethylation takes place to allow for active transcription. When and how this process occurs is unknown. In this study, we show that KIR proximal promoters are densely methylated in less mature CD56 bright NK cells and are progressively demethylated in CD56 dim NK cells as they mature and acquire KIR. We hypothesized that ten-eleven translocation (TET) enzymes, which oxidize 5mC on DNA could mediate KIR promoter demethylation. The catalytic efficiency of TET enzymes is known to be enhanced by ascorbic acid. We found that the addition of ascorbic acid to ex vivo culture of sorted CD56 bright NK cells increased the frequency of KIR expression in a dose-dependent manner and facilitated demethylation of proximal promoters. A marked enrichment of the transcription factor Runx3 as well as TET2 and TET3 was observed within proximal KIR promoters in CD56 bright NK cells cultured with ascorbic acid. Additionally, overexpression of TET3 and Runx3 promoted KIR expression in CD56 bright NK cells and NK-92 cells. Our results show that KIR promoter demethylation can be induced in CD56 bright , and this process is facilitated by ascorbic acid.

Ascorbic Acid Promotes KIR Demethylation during Early NK Cell Differentiation