摘要目的:观察CD5 +CD19 +B细胞在体外是否具有分泌IL-10的功能，并探讨其在HBV感染过程中对CD8 +细胞的作用和机制。 方法:纳入2017年7月至2018年6月在南京医科大学附属无锡第二医院确诊的慢性乙型肝炎(乙肝组)23例、肝硬化(肝硬化组)18例患者，以及同期健康对照(健康对照组)19名。通过外周血单个核细胞(PBMC)分离、细胞培养、流式细胞术分析、CD5 +CD19 +B细胞分离等操作，比较3组CD5 +CD19 +B细胞含量较多(占淋巴细胞百分比>6%)的患者比例、CD5 +CD19 +B细胞分泌IL-10的情况和IL-10 +细胞含量较多(占淋巴细胞百分比>4%)的患者比例，分析CD5 +CD19 +B细胞对CD8 +细胞分泌γ干扰素的影响和可能机制。通过对慢性乙型肝炎13例和肝硬化5例患者行肝活组织和免疫组织化学检查，分析CD5 +CD19 +B细胞在人体肝组织中表达情况。统计学分析采用卡方检验和Fisher确切概率法。 结果:肝硬化组中CD5 +CD19 +B细胞含量较多的患者比例高于健康对照组(8/18比2/19)，差异有统计学意义(Fisher确切概率法， P＝0.029)。健康对照组(10名)、乙肝组(23例)、肝硬化组(18例)的CD5 +CD19 +B细胞分别占IL-10 +细胞的81.6%、82.3%、70.1%，IL-10 +细胞含量较多的患者分别为2、7和2例，3组比较差异均无统计学意义( P均>0.05)。在脂多糖刺激培养48 h后，健康对照组(10名)CD8 +γ干扰素 +细胞占淋巴细胞百分比与乙肝组(10例)、肝硬化组(10例)比较(10.73%比7.05%和9.52%)差异均无统计学意义( P均>0.05)；剔除CD5 +CD19 +B细胞后，健康对照组(10名)、乙肝组(10例)和肝硬化组(10例)中分别有5、4、4例患者CD8 +γ干扰素 +细胞占淋巴细胞百分比升高。添加IL-10受体阻滞剂后，PBMC中CD8 +γ干扰素 +占淋巴细胞百分比较添加IL-10受体阻滞剂前升高(7.23%比6.87%)。肝活组织标本免疫组织化学分析结果显示，CD4 +和CD8 +细胞在患者肝小叶汇管区强表达，CD5 +和CD19 +细胞较少表达。 结论:CD5 +CD19 +B细胞在HBV慢性感染的进展过程中并未体现出明显数量和功能上的差异，但对CD8 +细胞分泌γ干扰素的能力具有抑制作用，并且可能是通过分泌IL-10而不是通过细胞间的直接接触实现。

abstractsObjective:To explore whether CD5 + CD19 + B cells has the function of secreteing interleukin-10 (IL-10) in vitro, and to further investigate its possible effects and mechanisms on CD8 + cells in the process of hepatitis B virus (HBV) infection. Methods:From July 2017 to June 2018, at Wuxi Second People′s Hospital Affiliated to Nanjing Medical University, 23 patients with chronic hepatitis B (chronic hepatitis B group), 18 patients with liver cirrhosis (liver cirrhosis group) and 19 healthy individuals in the same period as healthy controls (healthy control group) were enrolled. Peripheral blood mononuclear cell (PBMC) were isolated and cultured. CD5 + CD19 + B cells were isolated. The cells were analyzed by flow cytometry. The ratio of high CD5 + CD19 + B cells content (>6 % of lymphocytes), the secretion of IL-10 by CD5 + CD19 + B and the ratio of high IL-10 + cells content (>4 % of lymphocytes) of three groups were compared. The effects and possible mechanisms of CD5 + CD19 + B cells on the secreting of interferon-γ (IFN-γ) by CD8 + cells were analyzed. Liver biopsy and immunohistochemistry examination were conducted in 18 patients (13 patients with chronic hepatitis B and 5 patients with liver cirrhosis) and the expression of CD5 + CD19 + B cells in human liver tissues was analyzed. Chi square test and Fisher exact probability test were used for statistical analysis. Results:The ratio of high CD5 + CD19 + B cells content of liver cirrhosis group was higher than that of healthy control group (8/18 vs. 2/19) and the difference was statistically significant (Fisher exact probability test, P=0.029). The precentage of CD5 + CD19 + B cells in healthy control group ( n=10), chronic hepatitis B group ( n=23) and liver cirrhosis group ( n=18) accounted for 81.6%, 82.3% and 70.1%of IL-10 + cells, respectively, and the number of patients with high IL-10 + cells precentage was 2, 7 and 2, respectively. There were no statistically significant differences among three groups (all P>0.05). After stimulated with lipopolysaccharide and cultured for 48 hours, the precentage of CD8 + IFN-γ + cells in lymphocytes of healthy control group ( n=10), chronic hepatitis B group ( n=10) and liver cirrhosis group ( n=10) were compared, and the differences were not statistically significant (all P>0.05). After CD5 + CD19 + B cells were eliminated, the precentage of CD8 + IFN-γ + cells in lymphocytes increased in 5, 4 and 4 patients of healthy control group ( n=10), chronic hepatitis B group ( n=10) and liver cirrhosis group ( n=10). After adding IL-10 receptor blocker, the precentage of CD8 + IFN-γ + cells in lymphocytes in PBMC increased compared with that before the addition of IL-10 receptor blocker (7.23% vs. 6.87%). The results of immunohistochemistry examination of liver biopsy indicated that CD4 + and CD8 + cells were strong expressed in portal area of liver tissue of patients, while CD5 + and CD19 + were less expressed. Conclusions:CD5 + CD19 + B cells do not show obvious quantitative and functional differences in the process of chronic HBV infection, however the ability of CD8 + cells to secrete IFN-γ, which may be achieved by secreting IL-10 rather than by direct contact between cells.