丙戊酸钠对人外周血T淋巴细胞细胞因子表达的影响

目的: 研究丙戊酸钠(VPA)对人外周血T淋巴细胞的活化、凋亡及细胞因子表达的影响。方法: 双色荧光抗体染色结合流式细胞术分析VPA对多克隆刺激剂二丁酸佛波酯(PDB)和离子霉素(Ion)刺激下的人外周血T细胞CD69表达的影响,DiOC₆(3)染色检测VPA对T细胞凋亡的影响。 利用胞内细胞因子染色检测T细胞IL-2、IL-4、IFN-γ和TNF-α的表达,以探讨VPA的保护机制。 结果: VPA (1和5 mmol/L)对PDB和Ion诱导的人外周血T细胞CD69的表达具有明显的促进作用 (P<0.01)。DiOC₆(3)染色结果表明VPA(1和5 mmol/L)可以增强线粒体膜电势,抑制T细胞活化诱导的凋亡,高浓度则作用相反。胞内细胞因子染色分析显示,VPA在低浓度时能明显促进IL-2表达而高浓度时则抑制。同时,VPA能显著促进IFN-γ和TNF-α的表达(P<0.05),并呈剂量依赖性,而对IL-4表达的影响较小。结论: VPA对多克隆刺激剂诱导的人外周血T细胞的活化和凋亡具有双向调节作用,诱导IL-2、IFN-γ和TNF-α的表达。

Valproic acid exerts differential effects on cytokine synthesis in human peripheral lymphocytes

AIM: Valproic acid (VPA) is a histone deacetylase inhibitor and is believed to have anti-tumor activity. The present study aims to investigate the effect of VPA on the, apoptosis and cytokine synthesis of human peripheral lymphocytes. METHODS: The activation and cytokine synthesis in lymphocytes in whole blood stimulated with phorbol dibutyrate (PDB) and ionomycin were evaluated with flow cytometry after fluorescent staining. The mitochondrial membrane potential was examined using 3, 3-dihexyloxacarbocyanine iodide DiOC6(3)]staining. RESULTS: VPA at low doses (1 and 5 mmol/L) promoted CD69 expression in activated lymphocytes, whereas it turned to inhibit the expression of CD69 at a high dose (25 mmol/L). Meanwhile, VPA at low doses increased the mitochondrial membrane potential, while a high dose of VPA decreased it in activated lymphocytes. Furthermore, interleukin-2 (IL-2) synthesis was enhanced by low doses of VPA but inhibited by a high dose. However, interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) synthesis were dose-dependently enhanced by VPA as compared with those of PDB plus ionomycin-treated cells. CONCLUSION: VPA exerts biphasic effect on the further activation and apoptosis of human peripheral lymphocytes stimulated with mitogens and exhibits differential activity on the synthesis of several important cytokines in human lymphocytes.