ABSTRACT
@#[摘 要] 目的：设计并制备一种分别靶向B细胞表面抗原CD19和CD22的CAR-T细胞，检测其对肿瘤细胞的体内外杀伤效果。方法：将含有人源化 CD19 ScFv的二代CAR分子和带有CD3ε链作为共刺激结构域的CD22 ScFv CAR分子以P2A自剪切肽连接，序列连接于慢病毒载体pLTR-CMV-MCS中，以HEK-293T细胞包装相应的慢病毒载体，感染健康志愿者提供的T细胞制备CAR-19-22-T细胞，同时以相同二代结构分别构建单靶向CAR-T细胞作为参照。构建表达荧光素酶、CD19和/或CD22的前列腺癌3M细胞（靶细胞）。将各种CAR-T细胞与靶细胞共同培养，采用荧光素酶化学发光法和ELISA法检测其对靶细胞的杀伤能力和细胞因子的分泌水平。通过尾静脉注射Raji-Luc细胞构建NOD-SCID免疫缺陷小鼠白血病模型，分别注射各组CAR-T细胞进行治疗并评估其疗效。结果：培养7 d的CAR-19-22-T细胞的CAR-19表达率为13.7%，CAR-22表达率为14.3%。CAR-19-22-T细胞在10∶1效靶比时，对3M-CD19-Luc、3M-CD22-Luc和3M-CD19-CD22-Luc细胞的杀伤率均显著高于T细胞[（78.1±14.4）% vs （11.1±4.3）%、（46.7±10.7）% vs （12.4±2.7）%、（90.5±4.3）% vs （14.3±3.7）%，均P<0.01]；与3M-CD19-Luc、3M-CD22-Luc、3M-CD19-CD22-Luc靶细胞共培养后，CAR-19-22-T细胞IFN-γ、TNF-α和IL-2水平均显著低于CAR-19-T和CAR-22-T细胞（P<0.05或P<0.01）。CAR-19-22-T细胞对移植Raji-Luc细胞模型小鼠治疗效果明显，其生存期显著长于T细胞组（P<0.01），与CAR-19-T组和CAR-22-T组荷瘤小鼠比较差异均无统计学意义（均P>0.05）。结论：成功设计并制备了一种双靶点CAR-19-22-T细胞，其能够有效杀伤表达CD19和/或CD22抗原的肿瘤细胞，对Raji-Luc细胞的白血病模型小鼠有显著的治疗效果。
ABSTRACT
Mesenchymal stem cells (MSC) are a popular candidate in cellular therapy for many diseases. MSCs are well known by their feature of self-renewal and their differentiation potential. NESTIN is a cytoskeletal protein expressed in MSC that functions directly in cell proliferation and differentiation. Here, we demonstrated that adding UltraGRO, a medium supplement, could maintain and partially recover the expression of NESTIN in human umbilical cord derived MSCs (UC-MSCs). Furthermore, the UC-MSCs cultured with UltraGRO showed a better immunomodulation ability in a colitis mouse model compared with those cultured in other types of media. This indicates that the use of novel culture medium benefits the maintenance of NESTIN expression and NESTIN may be one of the vital factors that regulates the performance of MSCs.
