Fig. 2

Immunogen design and verification. a Cell lines expressing various antigens were established as the immunogens. mPD-1- and mLAG-3-expressing U-2 OS cells were established by lentivirus transduction and were verified by flow cytometry with the indicated antibodies. b Cell-based ELISA was established to verify the mPD-1-, mLAG-3- and mAFP-expressing U-2 OS cells. The mPD-1-, mLAG-3- and mAFP-expressing U-2 OS cells were fixed and stained with the indicated antibody and thereafter visualized by Immunospot Analyser