ABSTRACT
@# Objective： ：To explore a novel chimeric antigen receptor (CAR)-T cell treatment to treat Multiple Myeloma (MM) via target B cell maturation antigen (BCMA). Methods： ：A CAR-BCMA molecular was constructed based on mouse originated BCMA scFv, and was packaged into lentiviral vector and transfected into T cells from healthy donors to construct CAR-BCMA-T cells. The BCMApositive cell lines A549-BCMA, A549-BCMAOFP and K562-BCMA were constructed as target cells. Then, the CAR-BCMA-T cells were co-incubated with the constructed target cells and human myeloma U266 cells, and the cytotoxic effects of CAR-BCMA-T cells were evaluated via CCK-8 and FACS. Finally, the CAR-BCMA-T cells originated from MM patients were constructed, and its cytotoxicity against A549-BCMA were examined; in addition, the IFN-γ release level in CAR-BCMA-T cells was evaluated by ELISA and FACS. Results: After 11 days’incubation, the CAR-BCMA-T cells originated from healthy donors amplified 300 times with a positive rate of 43%. The BCMApositive target cell lines were constructed successfully. Under an effector : target ratio of 5:1, the killing rates of CARBCMA-T cells against A549-BCMA, K562-BCMA and U266 were about 80%, 60%, and 80%, respectively, which were significantly higher than those against BCMA negative cells; and the cytotoxicity was related to the BCMA expression level in target cells. What’ s more, at the effector : target ratio of 20:1, the CAR-BCMA-T cells originated from MM patients were demonstrated to exhibit a killing rate of more than 95% againstA549-BCMApositive cells, and produced large amount of IFN-γ. Conclusion: CAR-BCMA-T cells originated from both healthy and MM donors were successfully constructed, and they can effectively and specifically kill BCMA positive tumor cells.
ABSTRACT
B cell maturation antigen (BCMA) is a receptor of B lymphocyte stimulator (BLyS). Human IgG1Fc fusion proteins with the extracellular domain of BCMA(eBCMA), also called decoy receptors, have beenused as a potential BLyS antagonists to block BLyS activities. In order to design novel BLyS antagonistpeptides, computer-aided homologue modeling was used to construct an eBCMA-Fc fusion protein based on thecrystal structures of BCMA and Fc fragmant. To ensure the activity of eBCMA not to be interfered by Fcfusion, the root mean square distance (RMSD) for eBCMA and Fc were calculated to be 0.036 nm and 0.064nm, respectively, based on molecular docking modeling. An eBCMA-Fc fusion gene was constructed andintroduced into E. coli for expression. As expected, the purified 36 kD eBCMA-Fc fusion protein was able tobind BLyS in vitro at a dosage-dependent manner and demonstrated an anti-proliferative activity induced byBLyS in Daudi cells. The results have provided useful information on the evaluation of computer modeling andthe in vitro biological activity for the design of potential BLyS antagonist peptides.