Cloning of human PD-1 molecule and its expression on COS-7 cells

Objective: To clone full-length human PD-1 encoding sequence and express functional PD-1 molecule on the COS-7 cells. Methods: PCR technique was used to clone the full-length DNA encoding PD-1 molecule from human activated T cell cDNA library .The PCR product was digested and inserted into pcDNA3.1(+) vector and sequenced. The right recombinant was transfected into COS-7 cell by lipofectamine reagent. The expressions of PD-1 molecule on the membrance of COS-7 cells were detected with FACS. Results: A fragment about 880 bp was cloned from human T cell cDNA library, and was subsequently digested and cloned into pcDNA3.1(+) vector. Sequence analysis demonstrated that the fragment was common with published PD-1 encoding sequence. Twenty one point one percent cells were detected for expressing human PD-1 molecules. Conclusion: This study makes it possible to further investigate the role of PD-1 molecules in immune tolerance and autoimmune disease.