OBJECTIVETo explore the killing effect of CAR (CD138-CD28-CD3ζ)-NK cells on myeloma cells through construction of CAR(CD138-CD28-CD3)-NK cells.

METHODSThe antiCD138scFv-CD28-CD3 zeta plasmid pcDNA3.1 was constructed, which then together with 3 plasmid lentiviral packaging system were transfected into 293T cells, the virus was collected. Furthermore, in order to get the stably transfected cell line, the NK92MI cell line was infected by the virus, then the positive cells were screened by puromycin. The expression of the CARNK cells were verified by RT-PCR and Western blot. At last the ability of secreting cytokine CD107a was detected by flow cytometry, and the statistical analysis was carried out to verify the anti-myeloma effect of CAR-NK cells.

RESULTSGene fragment of the CAR(antiCD138scFv-CD28-CD3ζ) was constructed successfully by gene engineering technique in vitro, and the gene sequence was verified to be correct by sequencing. By virus packaging technology, the virus expressing the protein of the CAR was obtained. PCR and Western blot verified the expression of CAR fusion protein on the sufurce of NK cells. The cell killing experiment confirmed that the CAR-NK cells possessed the ability to secrete cytokine CD107a superior to control cells and showed the obvious killing effect on multiple myeloma cells.

CONCLUSIONThe CAR can be constructed in vitro, and express on NK92 cells. The CAR-NK cells can kill the multiple myeloma cells expressing CD138 antigen, thereby plays an antimyeloma effect.