阻断B7/CD28及CD40/CD154共刺激信号对致敏小鼠免疫功能的影响  

Influence of Blocking B7/CD28 and CD40/CD154 Co-stimulatory Signals on Immune Function of Sensitized Mice

作　　者：叶启翔[1] 许吕宏[1] 许威[1] 方建培[1] 

机构地区：[1]中山大学孙逸仙纪念医院儿科,广东广州510120

出　　处：《中国实验血液学杂志》2014年第3期801-806,共6页Journal of Experimental Hematology

基　　金：高等学校博士学科点专项科研基金(20090171110064);广东省科技计划社会发展项目(2012B031800074)

摘　　要：本研究旨在通过阻断致敏小鼠的B7/CD28及CD40/CD154共刺激信号途径,探讨其免疫功能的变化,为应用于异基因骨髓移植的免疫耐受提供实验依据。将致敏的BALB/c小鼠分成4组:①CTLA4Ig+anti-CD154鼠源性同型对照抗体;②anti-CD154单克隆抗体+CTLA4Ig鼠源性同型对照抗体;③CTLA4Ig+anti-CD154单克隆抗体;④CTLA4Ig及anti-CD154单克隆抗体的鼠源性同型对照抗体。正常BALB/c小鼠应用CTLA4Ig及antiCD154单克隆抗体的鼠源性同型对照抗体。给予每只小鼠CTLA4 Ig和anti-CD154单克隆抗体或相对应的同型对照抗体各500μg,于移植前7天尾静脉输注,每组小鼠各5只。移植当天处死各组小鼠,应用流式细胞仪检测脾细胞中CD19+CD69+B细胞数量、CD44high/CD62Lhigh及CD44high/CD62Llow/-T细胞数量。用流式细胞仪或ELISA法检测血清中抗体及细胞因子的变化。结果表明:小鼠致敏后CD19+CD69+B细胞数量与正常小鼠相比明显升高,差异有统计学意义(P<0.01),阻断B7/CD28或/和CD40/CD154共刺激信号通路后可见抑制效应(P<0.01),两者同时阻断具有协同作用(P<0.01)。小鼠致敏后记忆性T细胞CD44high/CD62Lhigh及效应性T细胞CD44high/CD62Llow/-与正常相比亦明显增多(P<0.01)。阻断共刺激信号通路后可使其明显抑制,CTLA4 Ig和anti-CD154单克隆抗体联合应用具有协同效应(P<0.01)。各组小鼠细胞因子及IgG、IgM抗体均无明显差异(P>0.05),但血清中致敏抗体检测显示致敏后特异性抗体升高,阻断共刺激信号通路后其明显被抑制(P<0.01)。结论:阻断B7/CD28或CD40/CD154共刺激信号途径均能抑制致敏小鼠的细胞免疫功能及体液免疫功能;同时阻断有协同作用。This study was aimed to explore the effects of blocking B7/CD28 and CD40/CD154 co-stimulatory signals on immune function of sensitized mice＇, and provide the evidences of acquired immune tolerance for ailogeneic bone marrow transplantation. The mice sensitized on 7 day before transplant were divided into 4 groups ： （ 1 ） CTLA4Ig ＋ anti-CD154 isotype control IgG; （ 2 ） anti-CD154 ＋ CTLA4Ig isotype control IgG; （ 3 ） CTLA4Ig and anti-CD154 ; （ 4 ） isotype control IgG of CTLA4Ig and anti-CD154. CTLA4Ig and anti-CD154 used in normal BALB/c mice as isotype control lgG. Each mouse in all groups received CTLA4Ig and anti-CD154 （or corresponding isotype control IgG） 500 μg respectively, and was injected via tail vein on 7 day before transplant. There were 5 mice in each group. The mice were sacrificed on day 0, then the number of CD19 ＋ CD69 ＋ B cells, CD44high/CD62Lhigh and CD44high/CD62LloW/- T cells were measured by flow cytometry. Changes of cytokines and sensitized antibody were tested by ELISA or flow cytometry. The results showed that the numbers of CD19 ＋ CD69 ＋ B cells were significantly increased in comparison with the normal group （ P 〈 0.01 ）, whereas the numbers of cells were significantly decreased when blocking B7/CD28 or / and CD40/CD154 co-stimulatory signals（ P 〈0.01 ）. Blocking these 2 signals together displayed a synergistic effect（ P 〈 0. 01 ）. The central memory and effector T cells were defined as CD44high/CD62Lhigh and CD441aigh/CD62Llow/- respectively, those increased significantly after sensitized in comparison with those in normal group, whereas their numbers decreased when blocking B7/CD28 or/and CD40/CD154 co-stimulatory signals. Blocking these two signalstogether, displayed a synergistic effect （P 〈 0. 01 ）. Cytokines, IgG and IgM in all groups were not significantly different. Sensitizing antibody test showed that the fluores-cence intensity of sensitized group significantly increased as compared with normal group, whereas fluores

关 键 词：共刺激信号 B7CD28 致敏 CTLA4 IGG anti—CD154 

分 类 号：R392.1[医药卫生—免疫学]