Preparation Of Mouse Anti-human PD-1 Monoclonal Antibodies And Studies On Their Biological Activities

T and B lymphocytes need two signals during the immune response. The first signal is the binding of antigen with TCR on T cells. The second signal is the binding of co-stimulate on the APC with their receptors presenting on T and B lymphocytes. Then, T and B lymphocytes are activated, proliferated and displaying an immune response. PD-1 is the receptor presenting on the surface of T and B lymphocytes. It is a 50-55 kDa type I transmembrane receptor, belonging to member of IgG superfamily. PD-1 is expressed on T and B lymphocytes while activated, and it is also expressed on activated monocytes and myeloid cells. PD-1 can also be found on thymus and bone marrow during the development. PD-1 plays a negative regulatory role when combining with its ligands named PD-L1/PD-L2 during immune response. To further explore the function of PD-1 in immune response and their mechanism, we amplified human PD-1 gene, constructed recombinant retro virus vector, and obtained PD-1/L929 transfectant cell lines that could stably express human PD-1 molecules. Furthermore, preparation of mouse anti-human PD-1 mAbs, and its biological characteristics and the functions on T cells proliferation had been studied. This study has provided an effective way to further study the activities of PD-1 mAbs and PD-1/PD-L pathway in immune regulation.1, Amplifying of human PD-1 gene, construction of PD-1/L929 transfectant cells and study on its biological activitiesHuman PD-1 full length gene was amplified by PCR (polymerase chain reaction) through Pst I site mutation from pGEX-5X-3-PD-1 (constructed by our laboratory), and recombinant retro virus vector containing PD-1 gene was constructed and PD-1/L929 transfectant cell lines were established. The PD-1/L929 transfectant cell lines could stably express high level of PD-1 molecules. The effect of PD-1/L929 cells on maturation of dendritic cells was studied. The result showed that PD-1 transfectant cells could promote...