polybrene 与 retronectin 作为转导增强剂对基于 VHH 的 CD19 重定向 CAR-T 细胞发育与表型特征的影响：一项比较研究

Chimeric antigen receptor T cells (CAR T cells) have improved the prognosis of patients with certain hematologic malignancies.

However, broader clinical application of this type of therapy is dependent on production protocols.

We characterized VHH-based CD19-redirected CAR T cells generated using the transduction enhancers (TEs) polybrene or retronectin. The proliferation rate of activated T cells transduced using polybrene concentrations > 6 mg/mL decreased compared with untreated group. There was a direct relationship between polybrene concentration and transduction efficacy.

Moreover, we demonstrated the proliferation of retronectin-transduced T cells increased in a dose-dependent manner (4-20 g/mL). Whereas, different retronectin concentrations did not mediate a significant increase in T cell transduction rate.

Moreover, lentiviral transduction rate was also dependent on the concentration of lentiviruses. At optimized TE concentrations, multiplicity of infection (MOI) of > 10 decreased living T cell transduction rate.

Additionally, we demonstrated that CAR T cell phenotype is highly affected by TE type. Na ve T cell differentiation to central memory T cell was observed in the beginning of the expansion process and effector memory T cells became the predominant subset in the second week of expansion.

Importantly, retronectin increased the proliferation of CAR T cells alongside medicating higher transduction rates, resulting in more na ve and central memory T cells.

We demonstrated that a higher percentage of CAR T cells were generated using retronectin (with a less differentiated phenotype) making retronectin a more effective TE than polybrene for long-term CAR T cell processing in preclinical or clinical studies.