[Study on the Regulation of Chidamide on CD8+T Cells in T-cell Acute Lymphoblastic Leukemia].

OBJECTIVE: To explore the regulatory effect of chidamide on CD8+ T cells in T-cell acute lymphoblastic leukemia. METHODS: The expression levels of CXCL9 and CXCL3 mRNA in Jurkat cells, lymphocytes treated with chidamide and lymphocytes co-cultured with chidamide-treated Jurkat cells were detected by fluorescence quantitative PCR. The proportion of CD8+ T cells in lymphocytes treated with chidamide and lymphocytes co-cultured with chidamide-treated Jurkat cells was determined by flow cytometry. RESULTS: Chidamide upregulated CXCL9 mRNA expression in Jurkat cell line in a dose-dependent manner (r=0.950). The mRNA expression of CXCL9 in chidamide 5 µmol/L group was 164 times higher than that in control group. Chidamide upregulated CXCL9 mRNA expression in lymphocytes, but the up-regulated level was significantly lower than that in Jurkat cell line treated with the same concentration of chidamide. Co-culture with chidamide treated Jurkat cells upregulated the proportion of CD8+ T cells in lymphocytes. CONCLUSION: In T-cell acute lymphoblastic leukemia, chidamide may increase the concentration of CXCL9 in the tumor microenvironment by up-regulating the expression of CXCL9 in tumor cells, leading to an increase in the number of CD8+ T cells.

[Effect of HDAC Inhibitor Chidamide on PD-L1 Expression in Peripheral T-Cell Lymphoma].

OBJECTIVE: To explore the role of chidamide in the regulatory mechanism of PD-1/PD-L1 immune escape signaling pathway in peripheral T-cell lymphoma. METHODS: Jurkat cell line was treated with different concentrations of chidamide. The changes of PD-L1 and JAK/STAT pathway gene mRNA expression and PD-L1 protein expression on cell surface were detected by fluorescence quantitative PCR and flow cytometry after treatment. RESULTS: Chidamide upregulated PD-L1 mRNA expression in Jurkat cell line in a dose-dependent manner (r=0.989). The mRNA expression of PD-L1 in 5.0 µmol/L group was 15.4 times higher than that in the control group. The proportion of PD-L1 positive cells in Jurkat cell line was less than 0.5%. Chidamide upregulated PD-L1 protein expression on Jurkat cell surface. Chidamide upregulated the mRNA expression of JAK2, STAT1 and STAT3 in Jurkat cell line. The level of up-regulation was obvious in high concentration group (5.0 µmol/L group). Meanwhile, the mRNA expression of SOCS1 and SOCS3, the negative regulatory genes upstream of the JAK/STA T pathway, were up-regulated. CONCLUSION: In peripheral T-cell lymphoma, chidamide may up-regulate the expression of cell surface PD-L1 and induce T-cell chemokines by upregulation of STAT1 expression, thus improving the reaction rate of PD-1 monoclonal antibody and T-cell toxicity.