干燥综合征中白细胞介素-17与B细胞活化因子对B细胞功能异常的协同作用

Interleukin-17 acts in synergy with B cell-activating factor to influence B cell biology of primarySjogren＇ s syndrome

目的检测原发性干燥综合征（pss）患者血清和唇腺中B淋巴细胞活化因子（BAFF）的表达，通过BAFF、白细胞介素（IL）．17干扰扩增的Th17细胞与B细胞混合培养，探讨它们对B细胞功能的影响。方法选择确诊的pSS患者40例，酶联免疫吸附试验法检测pSS患者和健康对照血清中BAFF的表达；22例Dss做了唇腺活检和免疫组织化学染色；5例pSS采用流式细胞仪、免疫印迹法检测与BAFF和IL-17干扰扩增的Thl7细胞共培养的B细胞凋亡、增殖及抗体产生。采用t检验进行统计学处理。结果BAFF表达于Dss患者唇腺组织浸润的淋巴细胞及导管上皮细胞，腺泡与对照组几乎无表达。灶性浸润组BAFF阳性细胞数[（888±372）个]高于非灶性浸润组[（164±161）个]（t=5．94，P〈0．05）；BAFF阳性的淋巴细胞数占总淋巴细胞的比率[（0．18±0．08）％]高于非灶性浸润组[（0．09±0．07）％]（t=3．03，P〈0．05）；血清中pSS患者BAFF水平[（6．0±2．8）mg/ml]显著高于健康对照组[（3．8±1．7）ng/ml]（t=3．26，P〈0．05）；BAFF、IL-17转染组B细胞凋亡率分别为[（24±5）％、（23±5）％]显著高于未转染组[（7±4）％]（t值分别为4．6，4．4；P〈0．05），与单独培养的B细胞组相比差异无统计学意义（P〉0．05）。与对照组比较，部分培养的上清液中未检测出抗体。结论BAFF可能参与pSS局部炎症的损伤过程，其与IL-17对B细胞功能异常可能有协同作用。

Objective To identify interleukin 17 （IL-17） and B cell activating factor （BAFF） that could influence B cell biology by detecting the expression of BAFF in the serum and labial salivary glands from primary Sjtigren＇s syndrome （pSS） patients and to test the apoptosis rates of B cells cultured with Thl7 cells which were transfected with IL-17-siRNA, BAFF-siRNA. Methods A total of 40 patients with pSS who were referred to the Department of Rheumatology and Immunology at Anhui Provincial Hospital from June 2011 to June 2012 were enrolled into this study. The expression of BAFF on ~alivary gland and serum from pSS patients and healthy controls were detected by ELISA and immunohistoehemical examination （22 patients with pSS）. Flow cytometry was used to detect B cell＇s apoptosis, BAFF and IL-17 interfered with amplified Thl7 cells, and co-cultured with B ceils. Immunoblot was used to detect superuatant antibody in 5 patients with pSS. Independent samples t test was used for statistical analysis. Results In all pSS specimens, infiltrating inflammatory cells expressed BAFF, so did some duetual cells, but acinar cells did not express these markers. There was no expression of BAFF in the controls. BAFF-positive cell numbers in the labial salivary glands of pSS patients with focal infiltrating lymphocytes were more than that with non-focal infiltrating lymphocytes （888±372 vs 164＋161, t=5.94, P〈0.05）, and the percentage of BAFF-positive lymphocytes over the total infiltrating lymphocytes in the salivary glands of pSS patients with focal infiltrating lymphocytes[ （0.18±0.08）% ] was higher than those with non-focal infiltrating lymphocytes [ （0.09±0.07）%] （t=3.03, P〈 0.05）. The level of soluble BAFF in patients with pSS [（6.0±2.8） ng/ml] was significantly higher than the controls [（3.8±1.7） ng/ml, t=3.26, P〈O.05]. BAFF or IL-17 transfected group, B cell apoptosis rate [（24± 5）%, （23±5）%] were significantly higher than the non-transfected group [（7±4）%], t=4.6, 4.4; P〈0.05]. And there was no significant difference when compared with cultured B cells （P〉0.05）. Compared with the controls, no antibody could be detected in the supematants. Conclusion BAFF may be involved in the process of local inflammatory damage of the pSS, it may have a synergistic effect with IL-17 on abnormal B cell function.