Identification And Mechanism Of GMYL6 Functional Fragments

Objectives Differentiating and inducing highly active NK cells from human umbilical cord blood.An in vitro screening model was constructed to screen out in the g MYL6 series of small peptides that enhanced NK cell activity.After the intervention of active peptides,the effects of NK cells on the proliferation and apoptosis of K562 cells were investigated.The mode of action tumor cells,and the mechanism of tumor suppression were determined.Methods 1 Mononuclear cells were isolated from cord blood by Ficoll method to induce differentiation of NK cells.The maturation and activity of NK cells were verified by flow cytometry to ensure that more than 80% of mature NK cells were obtained.2 In vitro screening model was constructed using K562 cells as target cells.The concentration of small peptides was set at 25 ?M,50 ?M and 100 ?M.The CCK-8 method was used to screen out small peptides which could enhance NK cytotoxicity.One of the most powerful small peptides was studied in the follow experiments.3 To investigate the effects on proliferation and apoptosis,flow cytometry was used to assess cell cycle arrest.4 Apoptosis of target cells was observed by AO/EB fluorescence staining,and apoptosis was detected by flow cytometry with Annexin v/PI double staining.5 To explore the mechanism of small peptides on enhancing the killing activity of NK cells,the expression of some toxic proteins were detected by Western blotting,and real-time fluorescent nucleic acid quantitative PCR.Results 1 Highly active NK cells were successfully induced by Ficoll method.2 After screening small peptide D at 25 ?M enhanced NK cell killing activity is most significant,other concentrations of small peptides also have different degrees of effect.3 Small peptide D-assisted NK cells inhibit K562 cell proliferation,promote cell cycle arrest in G2/M phase,and promote target cell apoptosis.4 The possible mode of killing target cells is achieved by releasing the toxic protein perforin and the surface protein CD107 a of NK cells.Conclusions The research shows that small peptides have the effect on increasing the cytotoxic activity of NK cells.The possible mechanism is related to increase the secretion of perforin and CD107 a protein of NK cells.Ultimately NK cell can inhibit the growth of tumor cells and promote apoptosis of tumor cells.In this regard,small peptides can be used as an auxiliary drug for NK cells to enhance its anti-tumor effect,which can lay a foundation for subsequent research.Figure19;Table12;Reference 122...