Histone Methyltransferase G9a Regulates Function Of NK Cells

Objective:As a natural immune cell,NK cells play an important role in the immune system.At present,the study of NK Cells mainly focuses on the effects of NK cell surface receptors and related signaling pathways on its development and function,and our latest research shows that NK cells are associated with changes in chromatin and its histone modification status when they function.The histone methylation transfer enzyme(G9a)plays an important role in histone modification,and histone methylation transfer enzyme G9 a has an important effect on hematopoietic stem cells and T cell development,and whether the histone methylation transfer enzyme G9 a affects NK cell development and its function has not been reported.Therefore,it is important to study the role of histone methylation-transferase G9 a in NK cells,and this study mainly discusses how G9 a affects NK cell function and its mechanism from the G9 a of epigenetic.Method:Part I: From GEO database analysis of relevant data,the study of NK cells in the activation of the immune signal pathway,to find the most relevant to the NK cell function of histone methylation enzymes and the expression of the change,and the qPCR experiment to verify the histone methylation enzyme G9 a changes.The primary NK cells were selected from peripheral blood,and small molecule inhibitors were added to inhibit the activity of G9 a methylation transferase,and the expression of H3K9me2 in NK cells was changed after Western blot was added to small-molecule inhibitor.And the expression of IFN-γ in NK cells inhibited by g9 a activity was analyzed by flow cytometry.Part II: RT-PCR Analysis The expression of IFN-γ in gene level was observed in the case of NK cell line activated by different conditions stimulation,and the expression of IFN-γ protein level was detected by flow cytometry and ELISA.The modified level of H3K9me2 of IFN-γ in the NK cell line was detected in the NK cell line before and after the inhibition of the methylase activity of G9 a.Results:The first part: The high-throughput analysis showed that the expression of G9 a was reduced when NK cells were activated,and the ability of NK cells to secrete IFN-γcould be enhanced by inhibiting the activity of G9 a transferase in NK cells.The second part: in the two levels of gene and protein detection in NK cells,inhibit the activity of G9 a transferase,NK cells secrete IFN-γ ability to enhance;ChIP-qPCR experimental results showed that IFN-γ gene H3K9me2 was significantly decreased after inhibiting the activity of G9 a enzyme.Conclusion:1.G9 a can regulate the immune activation of NK cells.The activity of NK cells can be enhanced obviously after inhibiting the activity of G9 a enzyme.2.G9 a regulates the expression of IFN-γ gene H3K9me2 by regulating its level of modification,thus enhancing the ability of NK cells to secrete IFN-γ.