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Chromatin state dynamics during NK cell activation
1Department of Cell Biology, 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, Laboratory of Epigenetics in Development and Tumorigenesis, Tianjin Research Center of Basic Medical Sciences, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Medical University, Tianjin, China.
Abstract:
Studies of Natural Killer (NK) cell cytotoxicity have mainly focused on the balance of activating and inhibitory receptors, signaling transduction, calcium influx, formation of immune synapse, and cytolytic degranulation. However, little is known about the chromatin state of NK cells and the impact of its changes during target recognition. In this study, we investigate the contribution of chromatin state dynamics during NK cell activation by comprehensively analyzing a set of microarray data and two sets of Chromatin Immunoprecipitation-Sequencing (ChIP-seq) data. We find that the expression of several histone demethylases and methyltransferases was influenced upon stimulation. Furthermore, we notice that a series of genes, including PI3KCA, NFATC1and TNFSF9, which play important roles during NK cell activation, were at 'poised' state prior to activation, and that modifications of H3K4me3 and H3K27me3 on these promotors were sensitive to stimulation with Phorbol Myristate Acetate (PMA) and Ionomycin (Iono) in the NK92MI cell line. Finally, we demonstrate that a series of small molecule inhibitors, which are specific to H3K4 and H3K27 modification, enhance degranulation or the expression levels of IFN-γ and TNF-α. Our results suggest that the histone modification state has a profound impact on NK cell activation, and provide novel insights into the regulation of NK cellular cytotoxicity and immunoregulatory function by chromatin state dynamics.
Insights
Chromatin modifications significantly impact Natural Killer (NK) cell activation and function. Targeting histone modifications enhances NK cell cytotoxicity and cytokine production, offering new therapeutic strategies.
Area of Science:
- Immunology
- Epigenetics
- Cell Biology
Background:
- Natural Killer (NK) cell cytotoxicity research primarily focuses on receptor balance and signaling pathways.
- The role of chromatin state dynamics in NK cell activation remains largely unexplored.
Purpose of the Study:
- To investigate the contribution of chromatin state dynamics to NK cell activation.
- To analyze how changes in chromatin state affect NK cell function during target recognition.
Main Methods:
- Comprehensive analysis of microarray and Chromatin Immunoprecipitation-Sequencing (ChIP-seq) data.
- Investigated histone modification changes (H3K4me3, H3K27me3) on key genes (PI3KCA, NFATC1, TNFSF9) during NK cell activation.
- Utilized small molecule inhibitors targeting H3K4 and H3K27 modifications.
Main Results:
- Stimulation influenced the expression of histone-modifying enzymes (demethylases and methyltransferases).
- Key activation genes were in a 'poised' chromatin state, sensitive to stimulation.
- Inhibitors of H3K4 and H3K27 modifications enhanced NK cell degranulation and cytokine (IFN-γ, TNF-α) expression.
Conclusions:
- Histone modification state profoundly impacts NK cell activation.
- Chromatin state dynamics offer novel regulatory mechanisms for NK cell cytotoxicity and immunoregulatory functions.