摘要
探讨小鼠髓系DC (CD8α )中PD L1和PD L2的表达及其在T淋巴细胞活化中的作用。采用mCD4 0L CHO和TNF α分别刺激凋亡肿瘤细胞负载DC 4 8h ;免疫荧光标记检测DC表型 ;RT PCR和realtime PCR检测PD L1和PD L2mRNA转录水平 ;ELISA测定IL 2的分泌水平 ;3 H TdR掺入试验和51Cr释放试验测定DC体外激发T细胞的增殖和细胞毒杀伤率。结果显示 :PD L1和PD L2随着DC的成熟呈上调表达 ,CD4 0配基化DC的PD L1和PD L2均为中度表达 ,TNF α激发的DC为高度表达 ,二者呈现差异性表达 (P <0 0 5 ) ;CD4 0配基化髓系DC分泌IL 2的量明显高于TNF α组 (P <0 0 5 ) ,体外刺激T增殖和激活CTL能力在CD4 0配基化DC组最高 (P <0 0 5 )。提示CD4 0配基化的小鼠髓系DC呈现PD L1和PD L2的中度表达 ,IL 2大量分泌 。
This study was designed to investigate the expression of PD-L1 and PD-L2 in mouse myeloid dendritic cells (CD8α) and its effects on the activation of T lymphocytes. Apoptotic tumor cells pulsed dendritic cells (DC) were induced for further maturation by mCD40L-CHO cells and TNF-α for 48 hrs. 3 H-thymidine incorporation assay and standard 4 hrs 51Cr release assay were used to detect the proliferation and activation of CTL stimulated by DC. Expressions of PD-L1 and PD-L2 were analyzed by FCM and the mRNA of these molecules was detected by RT-PCR and real-time PCR. The concentration of IL-2 in the supernatants of DC cultures was determined by ELISA assay. Results demonstrated that PD-L1 and PD-L2 were up-regulated during the process of DC maturation and the differential expressions of these two molecules were obvious on DC stimulated by mCD40L-CHO cells or TNF-α. The proliferation and activation of CTL in vitro induced by CD40 ligation DCs were more powerful than those in other groups. Moreover,CD40 ligation was a potent signal for DC to induce IL-2 secretion. With moderate expressions of PD-L1 and PD-L2 and high levels of IL-2 secretion,the CD40 ligation DC could sustain a longer period of activation and may be more potent to activate T lymphocytes.
出处
《现代免疫学》
CAS
CSCD
北大核心
2004年第1期13-17,共5页
Current Immunology
基金
国家重点基础研究发展规划 ( 973计划 )资助项目( 2 0 0 1CB5 10 0 3 )
