[Preparation and characterization of three novel monoclonal antibodies against human PD-L1].

AIM:To prepare a functional mouse anti-human PD-L1 monoclonal antibody and to characterize its biological activities. METHODS:A stable human PD-L1 transfected cell line L929/PD-L1 was used as an antigen to immunize BALB/c mice. By means of the cell fusion technique, multiple cell subcloning, repeated screening with L929/ PD-L1 as target cells and the L929/mock cells used as the negative control, the hybridomas specifically secreting mouse anti-PD-L1 monoclonal antibodies were generated. Then its biological characterization was investigated by rapid murine Ig-subclass typing, Western blotting, indirect immune of luorescene assay, mutual competitive inhibition test. By means of MTT incorporation assay, detected the infection of mAb to T cell proliferation. Three mouse anti-human PD-L1 monoclonal antibodies were generated, named as 11G8, 2G5 and 5C3. RESULTS:The results of characterization study showed that the monoclonal antibodies could recognize the PD-L1 on the activated T cells. The mAbs could promote T cells proliferation. CONCLUSION:It is evident that the functional monoclonal antibodies for human PD-L1 have been generated, and it would provide the initial material for further study on the role of PD-1/PD-L1 signaling pathways.