穿膜序列对MHC-Ⅰ类限制性CTL表位呈递影响的研究

Effect of cell-penetrating peptides on MHC class Ⅰ restricted CTL epitope presentation

目的 :从时间依赖性抗原呈递动力学的角度研究穿膜序列 (CPP)对 MHC- 类限制性 CTL 表位呈递的影响。 方法 :应用多肽固相合成技术 ,分别合成含 CPP与 H- 2 Kb限制性 CTL 表位 OVA2 57- 2 6 4的融合多肽 ,同时合成该表位 N、C端自然延伸的抗原肽和无关对照肽。采用流式细胞仪 (FACS)分析技术 ,检测抗原呈递细胞 (APC)在不同时相点对上述各抗原肽进行 MHC- 类呈递的情况。结果 :与不含 CPP的抗原肽相比 ,含 CPP的抗原肽中的 CTL 表位更易进入 APC内 MHC- 类呈递途径 ,表现为呈递所需时间明显缩短 (P<0 .0 5 ) ,且同一时相点的呈递强度显著增加 (P<0 .0 5 )。 结论 :在外源性抗原肽中引入穿膜序列可明显促进其 MHC- 类限制性 CTL 表位的呈递效率 。

Objective:To explain the effect of cell penetrating peptides (CPP) on enhancing the immunogenicity of exogenous antigenic peptides through kinetic analysis of time dependent MHC class Ⅰ antigen presentation.Methods:Peptides containing CPP and an H 2K b restricted CTL epitope OVA 257 264 were synthesized by standard solid phase Fmoc chemistry.An N and C terminal extended epitope and an irrelated peptide were used as control.Time dependent kinetics of MHC class Ⅰ antigen presentation was detected by APC fed with these peptides using flow cytometer analysis.Results:Antigenic peptides containing CPP were presented much more effectively by MHC class Ⅰmolecules than those without CPP.Conclusion:CPP can effectively enhance the immunogenicity of exogenous antigenic peptides by promoting MHC class Ⅰ antigen presentation.