Immunophenotypic characteristics of CD19 chimeric antigen receptor( CAR)-transfected Nalm-6 cells / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the immunophenotypic characteristics of potential leukemia cells transfected with CD19 antigen receptor( CAR) during CAR-T cell preparation. Methods Morphological chan-ges in CD19 CAR-transfected cells were observed under inverted microscope. The transfection rate and immuno-phenotype of transfected Nalm-6 cells were analyzed by flow cytometry. Secretion of cytokines in the culture sys-tem was detected by chemiluminescence. Results The transfection rate of Nalm-6 cells by CD19 CAR was (46. 50±3. 78) ％ and that of KG1a cells was (15. 70±1. 22) ％. CD19 CAR-transfected Nalm-6 cells prolifer-ated more rapidly than Nalm-6 cells ( P values on 0 d, 4 d, 7 d and 12 d were 6. 339, 3. 447, 0. 012 and 0. 009). In the culture of CD19 CAR-transfected Nalm-6 cells, cell aggregation and adhesion were observed and they gradually gathered into a group. The rate of CD19 expression was only 1. 19％ in the CD19 CAR-transfect-ed Nalm-6 cell culture system with the transfection rate of (46. 50±3. 78) ％. After increasing the proportion of Nalm-6 cells in the culture system, CD19 expression was gradually increased, while the expression of CD22 re-mained stable. CD19 expressed by Nalm-6 cells cultured in the supernatant of CD19 CAR-transfected Nalm-6 cell culture system was decreased gradually. The levels of IL-10 and TNF-αsecreted by CD19 CAR-transfected Nalm-6 cells were higher than those by Nalm-6 cells. Conclusions Results of the immunophenotypic analysis of CD19 CAR-transfected leukemia cells suggested that CD22 CAR-T cell therapy could be used as a rescue or combination therapy for CD19 CAR transfection into leukemia cells.