摘要
PD-1(Programmed cell death 1)是一种抑制性的受体,是免疫球蛋白超家族的成员.大量研究证明PD-1能被诱导而在活化的T淋巴细胞、B淋巴细胞、NKT细胞和单核细胞上表达,从而在慢性感染的病因学中起着重要作用.树鼩(Tupaiabelangeri)做为一个理想的模型可被应用于许多人类感染性疾病如乙型病毒性肝炎.为了充分利用树鼩对于感染性疾病的宿主免疫应答模型,我们分离出树鼩PD-1基因.利用迅速扩增cDNA末端PCR(RACE-PCR)技术,从树鼩脾组织中克隆了PD-1基因的全长cDNA序列.序列分析显示树鼩PD-1 cDNA的开放阅读框编码一个由242个氨基酸组成的跨膜蛋白,并且和人类、灵长类和啮齿类中的同源基因有高度相似性.组织分布分析表明在所检测的几种组织中PD-1基因只在脾中表达.此外,淋巴细胞刺激实验显示,利用PMA和ionomycin刺激新鲜分离的树鼩外周血单核细胞(PBMCs)能够诱导PD-1 mRNA水平上的表达.我们的结果为将来进一步探讨树鼩的免疫功能提供了良好的基础.
Programmed cell death 1 （PD-1） is an inhibitory receptor that belongs to the immunoglobulin （Ig） superfamily. Numerous studies have demonstrated that PD-1 expression can be induced in activated T tymphocytes, NKT cells, B lymphocytes and monocytes and play a critical role in the pathogenesis of chronic infections. Tupaia belangeri （tree shrew） represents an excellent model for some of the major human infectious diseases such as hepatitis B virus infection. To fully utilize tree shrew as a host immune response model to infectious diseases, tree shrew PD-1 was isolated. Full-length tree shrew PD-1 cDNA was cloned from spleen of tree shrew by rapid amplification of cDNA end-PCR （RACE-PCR）. Sequence analysis revealed that the open reading frame （ORF） of tree shrew PD-1 cDNA encoded a predicted transmembrane protein of 242 amino acids with high homology with humans, primates and rodents. Expression of PD-1 in tree shrew was detected in spleen but not in other organs by RT-PCR. Stimulation of freshly isolated tree shrew peripheral blood monouclear cells（PBMCs） with PMA and ionomycin increased the expression of PD-1 mRNA. Our results may provide a foundation for future exploration of tree shrew immune function.
基金
Supported by"100 Talents"Programand Overseas Teams of The Chinese Academy of Sciences and National Key BasicResearch(973)Program(2007CB512807).
