牙龈卟啉单胞菌脂多糖对CD4^+CD25^+调节性T细胞免疫抑制功能的影响  

Effects of Porphyromonas gingivalis lipopolysaccharide on immuno-suppressive function of CD4^+CD25^+ regulatory T cells

作　　者：赵川江[1] 徐琛蓉[2] 俞少杰[1] 章锦才[2] 

机构地区：[1]中山大学光华口腔医学院牙周科,广东广州510055 [2]广东省口腔医院牙周科,广东广州510280

出　　处：《中国微生态学杂志》2009年第2期149-151,155,共4页Chinese Journal of Microecology

基　　金：国家自然科学基金青年科学基金项目(30801296);广东省医学科学研究基金(A2007105);中山大学医科青年教师科研启动基金(2007028)

摘　　要：目的探讨牙龈卟啉单胞菌(Porphyromonas gingivalis,Pg)对CD4+CD25+调节性T细胞(regulatory Tcells,Tregs)免疫抑制功能的影响。方法采用酚水法提取Pg ATCC 33277株脂多糖(lipopolysaccharide,LPS)。免疫磁珠法分离BALB/c小鼠脾脏CD4+CD25+Tregs并进行体外培养,同时给予不同剂量(0～500 ng/ml)Pg-LPS干预,培养48 h后收集细胞及上清液。Real-Time PCR法测定培养细胞Foxp3 mRNA的表达,ELISA法分别测定细胞上清液中IL-10、TGF-β水平;采用体外淋巴细胞混合培养法对Pg-LPS干预后的CD4+CD25+Tregs进行功能抑制试验。结果Pg-LPS干预不影响CD4+CD25+Tregs分泌IL-10和TGF-β,但是能够显著上调CD4+CD25+Tregs Foxp3 mRNA的表达,增强其免疫抑制作用;当Pg-LPS浓度低于300 ng/ml时,CD4+CD25+Tregs Foxp3 mRNA表达以及免疫抑制作用的增强与Pg-LPS浓度之间呈剂量-效应关系。结论Pg-LPS能够增强CD4+CD25+Tregs的免疫抑制作用,这种免疫抑制增强效应可能与CD4+CD25+Tregs Foxp3基因表达的上调有关,并且不具有抑制性细胞因子依赖性。Objective To investigate the effects of P. gingivalis lipopolysaccharide （Pg-LPS） on immuno-supressire function of CD4^＋CD25^＋ regulatory T cells （Tregs）. Method Pg-LPS （ Pg strain, ATCC 33277） was prepared using phenol-water method. Tregs were separated from the BALB/c mice splenic cells in two steps by magnetic cell sorting （MACS） system.CD4^＋CD25^＋ Tregs were treated with different doses of Pg-LPS （0 =500 ng/ml） and cultured for 48 hours. The expression of Foxp3 mRNA in treated CD4^＋CD25^＋ Tregs is determined by real-time quantitative PCR. And the secretion of IL-10 and TGF-β were detected using ELISA method. Furthermore ,the direct suppressive effect of Pg-LPS treated CD4^＋CD25^＋ Tregs on CD4^＋CD25^＋ T lymphocytes proliferation was tested by the mixed lymphocytes reaction and measured by^3 H-Thymidine radioactive assay. Result The secretion of IL-10 and TGF-β by CD4^＋CD25^＋ Tregs were not influenced by Pg-LPS. However, Pg-LPS could significantly up-regulate the expression of Foxp3 mRNA and immuno-suppressive effect of CD4^＋CD25^＋ Tregs. When Pg-LPS was less than 300 ng/ml, there was a dose-effect manner existing between Pg- LPS and the expression of Foxp3 mRNA as wen as the immuno-suppressive effect of the treated CD4^＋CD25^＋ Tregs. Conclusion Pg-LPS could enhance the immm,o-suppressive effect of CD4^＋CD25^＋ ~ Tregs,which may correspond to the up-regulation of Foxp3 but not inhibitory cytokines.

关 键 词：牙龈卟啉单胞菌 脂多糖 CD4^+CD25^+调节性T细胞 FOXP3 

分 类 号：R78[医药卫生—口腔医学]