Screening And Identification Of A CD19 Monoclonal Antibody For CAR-Bascd Cell Therapy

Objective This study was performed to screen the CD19 monoclonal antibody by hybridoma technology and investigate whether the pCD19-CAR based on the screened antibody can improve the killing efficacy of NK-92 MI cells to CD19+ B-cell lymphoma cell lines. Methods Mice which immunized with peptide-KLH were used to prepare the CD19 monoclonal antibody and then sequenced the mAb. The sequence of the mAb was analyzed and the pCD19 fragment was cloned into the lentiviral vector, which already contained the CAR fragment and it would then be used to transfect NK-92 MI cells. Finally, cytotoxicity assay was performed to examine pCD19-CAR-NK-92 MI cells against B-cell lymphoma cells. Results We successfully obtained a CD19 monoclonal antibody with high specificity and constructed the pCD19-CAR based on the scFv of the CD19 mAb. The result of the cytotoxicity assay illustrated that the killing efficacy of pCD19-CAR modified NK-92 MI cells is higher than the killing efficacy of non-genetically modified NK-92 MI cells. It proves that pCD19-CAR-NK-92 MI cells could recognize CD19 antigen and significantly kill the CD19+ B-cell lymphoma cells, suggesting the potential value of pCD19-CAR in CD19+ B-cell lymphoma immunotherapy.