Abstract
Background. The use of CD19 chimeric antigen receptor (CAR) T cells to treat B-cell malignancies has proven beneficial. Several groups use serum to produce CD19 CART cells. Today, ready-to-use serum-free media that require no addition of serum are commercially available. Therefore, it becomes important to evaluate the production of CD19 CART cells with and without the addition of serum. Methods. T cells from buffy coats were cultured in AIM-V and TexMACS (TM) supplemented with 5% human serum (A5% and TM5%, respectively), and in TM without serum. Cells were activated with OKT3 and expanded in interleukin (IL)-2. Viral transduction was performed in RetroNectin-coated plates using the spinoculation method. CD19 CAR T cells were tested for their viability, expansion, transduction efficacy, phenotype and cytotoxicity. Results. CD19 CART cells expanded in A5% and TM5% showed significantly better viability and higher fold expansion than cells expanded in TM. TM promoted the expansion of CD8(+)T cells and effector phenotype of CD19 CART cells. The transduction efficacy and the cytotoxic function were comparable between the different media. Higher CD107a(+) cells were detected in TM and TM5%, whereas higher IL-2(+) and IL-17(+) cells were detected in A5%. CD19 CAR exhibited co-expression of inhibitory receptors such as TIM-3(+)LAG-3(+) and/orTIM-3(+)PD-1(+). Conclusion. Our results indicate that serum supplementation promotes better CD19 CAR T-cell expansion and viability in vitro. CD19 CART cells produced in TM medium showed lower CD4/CD8 ratio, which warrants further evaluation in clinical settings. Overall, the choice of culture medium impacts CD19 CART-cell end product.