CD44在新生隐球菌体外感染血脑屏障中对单核细胞迁移的影响

发布时间：2018-01-21 06:15

本文关键词： 新生隐球菌 CD 单核细胞血脑屏障迁移　出处：《南方医科大学学报》2015年04期 　论文类型：期刊论文

【摘要】：目的新生隐球菌(Cryptococcus neoformans,Cn)荚膜主要毒力因子透明质酸由CPS1基因编码,能与宿主细胞受体CD44结合介导真菌侵袭。本文目的明确CD44分子在Cn体外感染血脑屏障模型中对单核细胞黏附人脑微血管内皮细胞(HBMEC)并迁移穿越血脑屏障的影响。方法用单层HBMEC铺趋化小槽构建体外血脑屏障模型,利用Cn野生株B4500FO2、CPS1基因缺失株TYCC645#32和CPS1基因回补株PCIP,分别感染模型中的HBMEC,然后在上槽液中加入人白血病单核细胞(THP-1),计数从上槽液中迁移到下槽液中的单核细胞数量,观察Cn感染与单核细胞迁移时间和剂量关系;用抗CD44单克隆抗体和CD44抑制剂Bikunin分别作用于模型中单层HBMEC,通过趋化实验检查抗CD44单克隆抗体和Bikunin对Cn感染模型中单核细胞迁移的抑制效应。结果黏附和趋化实验结果显示,Cn感染HBMEC后,相比PBS对照组,THP-1黏附率和趋化效应均明显增加(P0.01),且黏附率和迁移率随Cn感染量和感染时间的增加而显著上升(P0.05)。通过抗CD44单克隆抗体和CD44阻断剂Bikunin分别作用于Cn感染后的HBMEC,结果发现THP-1黏附率和迁移率均显著降低(P0.01),且在一定范围内分别随抗体(0~1μg)和抑制剂(0~20 nmol/L)剂量的增加而减低。不同Cn菌株荚膜透明质酸的表达差异对THP-1细胞黏附和迁移有一定影响:与野生株相比,TYCC645#32感染组的THP-1黏附率和迁移率均明显降低(P0.01,P0.05),而回补株PCIP的THP-1黏附率和迁移率有所增加。结论体外血脑屏障模型中人脑微血管细胞表达CD44分子可能对单核细胞黏附内皮细胞和迁移通过血脑屏障起重要作用;荚膜透明质酸能介导Cn诱导的单核细胞黏附和迁移。
[Abstract]:The purpose of Cryptococcus neoformans (Cryptococcus neoformans Cn) the main virulence factor of capsular hyaluronic acid mediated by CPS1 gene encoding, can bind with host cell receptor CD44 mediated fungal invasion. The purpose of this paper is clear CD44 molecules in Cn infection in vitro BBB model on monocyte adhesion of human brain microvascular endothelial cells (HBMEC) and the effect of migration cross the blood-brain barrier. Using the method of single shop HBMEC chemotaxis slot in vitro BBB model was constructed, using Cn B4500FO2 TYCC645#32 and wild-type CPS1 gene, CPS1 gene deletion strain complemented strain PCIP, were infected in the HBMEC model, then add the human monocytic leukemia cell in bath (THP-1). Count on migration from the bath to bath in the number of mononuclear cells, observe the relationship between Cn infection and monocyte migration time and dose; model for single separately with anti CD44 monoclonal antibody and CD44 inhibitor Bikunin HBMEC, through chemotaxis experiments to examine the anti CD44 monoclonal antibody and Bikunin inhibitory effect on Cn infection of monocyte migration in the model. The experimental results show that the adhesion and chemotaxis, Cn infection after HBMEC, compared with PBS control group, THP-1 adhesion and chemotaxis effect were significantly increased (P0.01), and the adhesion rate and the migration rate increases with the amount and duration of infection of Cn infection increased significantly (P0.05). The anti CD44 monoclonal antibody and CD44 inhibitor Bikunin were added to Cn infection after HBMEC, the results showed that THP-1 adhesion and migration rates were significantly decreased (P0.01), and in a certain range respectively with antibody (0~1 G (0~20 nmol/L)) and the inhibitor dose decreases. Different strains of Cn capsular hyaluronic acid expression has a certain effect on the adhesion and migration of THP-1 cells: compared with wild-type, TYCC645#32 infection group THP-1 adhesion and migration rate were significantly decreased (P 0.01, P0.05), while covering the line PCIP THP-1 adhesion rate and migration rate increased. Conclusion the in vitro blood-brain barrier model in human brain microvascular cells expressing CD44 molecules may on cells and monocytes adhesion to endothelial migration plays an important role through the blood-brain barrier; capsular hyaluronic acid can mediate Cn induced monocytes cell adhesion and migration.

【作者单位】：南方医科大学公共卫生与热带医学学院//广东省热带病研究重点实验室微生物学系;南方医科大学第一临床医学院;美国南加州大学洛杉矶儿童医院;
【基金】：国家自然科学基金(81171644) 2013年度广东省级大学生创新创业训练计划项目(1212113033)~~
【分类号】：R519
【正文快照】： 新生隐球菌(Cryptococcus neoformans,Cn)是一种具有多糖荚膜的嗜中枢神经系统的病原真菌,能引起隐球菌脑膜炎,死亡率极高。新生隐球菌CPS1基因编码真菌透明质酸合成酶,能合成荚膜成分透明质酸(hyaluronic,HA),后者与Cn黏附侵袭脑微血管内皮细胞(brain microvascular endothel

【参考文献】