脐血与外周血NKT细胞的体外扩增及其表型比较

为了建立体外有效扩增脐血与外周血天然杀伤T细胞(NKT细胞)的方法并研究其表型的差异,分别采用单加IL-2及同时加IL-2和α-半乳糖神经酰胺(α-Galcer)的方法,从人脐血单个核细胞(UCB-MNC)和人外周血单个核细胞(PB-MNC)中扩增NKT细胞;用流式细胞检测技术测定NKT细胞(TCR Vα24+TCR Vβ11+)的比例及其它表型特征。结果显示:UCB-MNC在第7天时,其TCR Vαβ+NKT细胞的扩增量占淋巴细胞的(24.48±4·19)%,是原来的(8.74±4.37)×102倍(P<0.01),而且大多不表达NK1.1(CD161);TCR Vβ11+较TCRVα24+高表达;第14天时,PB-MNC中的TCR Vαβ+NKT细胞扩增量占淋巴细胞的(11.1±3.61)%,是原来的(3·72±2·01)×102倍(P<0.01),且NK1.1高表达,TCR Vβ11+与TCR Vα24+表达率基本一致。结论:α-Galcer对NKT细胞有特异的扩增功能,且脐血NKT的扩增效率较外周血高。以表型划分,脐血中的NKT细胞多为NK1.1-,而外周血多为NK1.1+,是一种新的NKT细胞亚型。

Proliferation of Natural Killer T Cel1s in Umbilical Cord Blood and Periperal Blood and Their Different Phenotypes

Purpose of this study was to establish an effective method in vitro to proliferate natural killer T (NKT) cells from umbilical cord blood (UCB) and peripheral blood (PB), and to study their different phenotype. Mononuclear cells (MNC) from UCB and PB were cultured in the presence of IL-2 (100 U/ml), with or without alpha-Galcer. TCR Valpha24 Vbeta11 double positive natural killer T-cells (NKT cells) and their other phenotypes were determined by flow cytometry. The results showed that after expansion for 7 days, TCRValphabeta(+) NKT cells from UCB-MNCs increased by (8.74 +/- 4.37) x 10(2) times as much, but most of them did not express NK1.1 and its TCR Vbeta11(+) was higher than TCR Valpha24(+). After expansion for 14 days, TCR Valphabeta(+) NKT cells from PB-MNCs increased by (3.72 +/- 2.01) x 10(2) times, the expression of NK1.1 was high and its TCR Vbeta11(+) was almost equal to TCR Valpha24(+). It is concluded that human TCR Valpha24 Vbeta11 double positive NKT cells can expand by addition of alpha-Galcer. The proliferation efficiency in UCB-MNCs is greater than that in PB-MNCs. Most of the UCB-NKT is NK1.1(-), while the PB-NKT is NK1.1(+), a new subset of NKT cells.