慢性乙型肝炎患者外周血树突状细胞诱导特异性T淋巴细胞应答

Dendritic cells originated from the peripheral blood in chronic hepatitis B patients can induce specific Tcell immune response

目的 探讨慢性乙型肝炎患者外周血树突状细胞(Dc)是否诱导特异性T细胞应答。方法(1)将研究对象分为慢性乙型肝炎患者组、急性乙型肝炎痊愈组、健康志愿者组,分离各组研究对象的外周血单个核细胞(PBMC),细胞内细胞因子染色方法检测其对细胞毒性T淋巴细胞(CTL)特异表位多肽乙型肝炎病毒核心抗原(HBcAg)18-27的记忆性免疫应答;(2)培养慢性乙型肝炎患者DC,将负载有乙型肝炎抗原表位多肽的DC诱导特异的T细胞应答。采用细胞内细胞因子染色方法检测诱导的T细胞分泌的细胞因子,乳酸脱氢酶释放法测定诱导的T细胞杀伤活性。结果(1)急性乙型肝炎患者PBMC对HBcAg 18-27 CTL特异表位多肽存在记忆的免疫应答,其分泌干扰素-γ的CD8+T细胞占CD8+T细胞总数的(4.3±2.5)％,分泌白细胞介素-2的占总细胞数的(4.8±2.2)％,分泌肿瘤坏死因子-α占总细胞数的(4.6±2.3)％。而慢性乙型肝炎患者和健康志愿者对其记忆应答很低,与急性乙型肝炎患者比较差异有显著性,t值为2.508-3.305,P<0.05。(2)用多肽共孵育过的慢性乙型肝炎患者DC多次诱导的T细胞慢性乙型肝炎患者组,加肽孵育的靶细胞比例为30:1、10:1、3:1时,其杀伤率分别为(57.0±20.3)％、(49.5±20.2)％、(21.8±12.9)％,均高于对照组,表明慢性乙型肝炎患者DC可以诱导特异的T?

Objective To study whether dendritic cells(DCs) derived from the peripheral blood in chronic hepatitis B patients can induce specific T cell immune response. Methods 1.The subjects were divided into 3 groups: chronic hepatitis B group(CHB), acute hepatitis B group (AHB), and normal donor group (ND). The peripheral blood mononuclear cells (PBMCs) isolated from those subjects were stimulated with HBcAg 18-27 CTL epitope peptide, and intracellular cytokine staining (ICCS) was used for detecting IFN- γ , IL-2 and TNF-α produced by CD8+ T cell. 2. DCs generated from PBMCs were pulsed with HBcAg 18-27 CTL epitope peptide, then were cocultured with autologous lymphocytes for 10 days to induce antigen-specific T cell, which was assessed by ICCS and cytotoxic assay. Results 1. The memory effect of the PBMCs from AHB group to HBcAg 18-27 CTL epitope peptide was stronger than that from CHB or ND group (r = 2.508-3.305, P < 0.05). 2. After lymphocytes were cocultured with DC treated with HBcAg 18-27 CTL epitope peptide, antigen-specific T cell effect was induced. And the killing rates were (57.0±23.0)%, (49.5 ±20.2)%, (21.8±12.9)% at the effector/target of 30:1, 10:1,3:1, which were higher than that in control group. Conclusions The memory T cells against HBV antigen lacks in CHB patients. DCs from CHB patients pulsed with HBcAg 18-27 epitope peptide can induce HBV antigen-specific T cell, which can kill specific target cells and produce cytokines involved in virus clearance.