CpG ODN2216刺激慢性乙型肝炎患者浆样树突状细胞表型和功能的变化

目的观察慢性乙型肝炎患者外周血浆样树突状细胞(pDCs)的特点,并探讨pDCs在乙型肝炎病毒(HBV)感染发病机制中的作用。方法收集20例慢性乙型肝炎患者和15名健康人外周抗凝血,应用流式细胞仪分析pDCs的频率；同时检测CpG ODN2216刺激后pDCs表型及分泌干扰素(IFN)α功能的变化；并分析HBV慢性感染患者外周血pDCs频率、数量和功能的变化及其与临床病情的关系。结果应用免疫磁珠分选技术可得到纯度大于95%的pDCs。经CpG ODN2216刺激后纯化的pDCs能高表达共刺激分子CD80、CD86、CD40和CD83,并分泌大量的IFNα。与健康人比较,HBV感染患者外周血中pDCs频率明显下降,分别为0．287%±0．142%和0．192%±0．110%；经CpG ODN2216刺激后,其表面共刺激分子CD80和CD40表达明显下降,产生IFNα的能力也显著降低,分别为(3142．9±1292．3) pg/ml和(972．6±705．5)pg/ml。相关性分析表明,患者pDCs产生的IFNα水平与丙氨酸氨基转移酶水平呈明显负相关,但与血清病毒载量无明显相关性。结论CpG ODN2216可以刺激pDCs成熟并分泌大量IFNα。慢性乙型肝炎患者外周血pDCs频率、表型和功能明显下降,这可能是HBV持续感染的重要致病机制。

Identification of circulating plasmacytoid dendritic cells in chronic HBV-infected patients

OBJECTIVE: To investigate the features of circulating plasmacytoid dendritic cells (pDCs) in patients with chronic hepatitis B for a better understanding of the immunopathogenesis of HBV infection. METHODS: Fresh blood samples were collected from 20 patients with chronic hepatitis B (CHB) and from 15 healthy individuals who served as controls. pDCs were isolated from peripheral blood mononuclear cells (PBMCs) using immunomagnetic assay and detected by flow cytometry. Fresh PBMCs and isolated pDCs were stimulated in vitro using CpG ODN2216. The supernatants were measured for IFNa production using ELISA. RESULTS: The peripheral pDCs frequency in CHB patients (0.192%+/-0.110%) was markedly lower than that in the healthy controls (0.287%+/-0.142%). After being pulsed with CpG ODN2216, the isolated pDCs produced lower levels of IFNa and expressed lower levels of CD80 and CD40 in the CHB patients when compared to those of the healthy controls. The level of IFNa was (972.6+/-705.5) pg/ml in the patients and (3 142.9+/-1 292.2) pg/ml in the controls. Moreover, the pDCs frequency was reversely correlated with serum ALT levels in these HBV infected patients. CONCLUSION: The reduced number and impaired function of circulating pDCs in patients with CHB may be related to their disease progression.