正常人外周血TCRVα24^+NKT细胞体外活化特性观察

The characteristics of TCRVα24^+NKT cells in response to in vitro stimulation

目的 :探讨正常人外周血自然杀伤T (NKT)细胞的数量以及体外活化后表达CD6 9、IFN -γ和IL - 4的规律并与CD3+ T细胞进行比较。方法 :取正常成人外周血 ,直接三色荧光标记后溶血获取有核细胞 ,或以佛波醇酯 (PDB) +离子霉素 (Ion)刺激并培养 6h ,经三色荧光标记后溶血并获取有核细胞 ,以流式细胞术分析NKT细胞和T细胞的数量以及表达CD6 9和IL - 4、IFN -γ的情况。结果 :NKT细胞约占外周血T淋巴细胞总数的 (1 34± 0 4 2 ) %( x±s) ;PDB +Ion活化 6h后NKT细胞CD6 9表达率为 (96 71± 1 33) % ,明显高于对照组 (11 4 7± 2 86 ) % (P <0 0 5 ) ;同样条件下CD3+ T细胞CD6 9表达率分别为 (98 6 0± 0 4 7) %和 (1 0 7± 0 4 5 ) % (P <0 0 5 ) ;当莫能菌素 (mon ensin)存在时以PDB +Ion刺激 6h后 ,IL - 4阳性NKT细胞的百分比为 4 8 6 2± 2 4 4 ,明显高于对照组 31 5 7± 3 31(P<0 0 5 ) ;IFN -γ阳性NKT细胞百分比为 4 6 6 5± 11 91,也高于对照组 13 4 5± 6 2 9(P <0 0 1)。CD3+ T细胞在刺激后表达IL - 4和IFN -γ均明显升高 ,但IL - 4表达率远远低于NKT细胞 ;而且对照组CD3+ T细胞两种细胞因子表达率都明显低于NKT细胞。结论 :正常成人外周血含有少量的NKT细胞 ,这些细胞IL - 4和IFN -γ?

AIM: To investigate the amount and patterns of expressing CD69 , IL-4 and IFN-γ on TCRVα24 +NKT cells, and compare with that of CD3 +T cells from human peripheral blood in response to in vitro stimulation. METHODS: The whole blood was stained with three-color immunofluorescence directly or after cultured with PDB+ionomycin(Ion) for 6 h, then the mononuclear cells were separated by lysing red blood cells. The expression rates of CD69, IL-4 and IFN-γ on TCRVα24 +NKT cells and CD3 +T cells were estimated by flow cytometer. RESULTS: As a proportion of mature T cells, the ratio of TCRVα24 + NKT cells to CD3 +T cells was about(1.34±0.42)%. The expression rates of CD69 on TCRVα24 + NKT cells and CD3 +T cells in response to PDB + Ion for 6 h were (96.71±1.33)% and (98.60±0.47)%, respectively, while the ratio were (11.47±2.86)% and (1.07±0.45)% in the unstimulated group, and there were significant difference between them. The expression rates of IL-4 and IFN-γ on TCRVα24 +NKT cells stimulated with PDB+Ion for 6 h were (48.62±2.44)% and (46.65±8.91)%, respectively ,which were significantly higher than that of unstimulated group [(31.57±3.31)%, (13.45±6.29)%] and that of stimulated CD3 +T cells, though the expression rates on stimulated CD3 +T cells were significantly higher than that of unstimulated CD3 +T cells. CONCLUSIONS: There is small amount of NKT cells in adult human peripheral blood. The expression rates of IFN-γ and IL-4 on these lymphocytes are higher than CD3 +T cells, suggesting that NKT cells are important immunomodulatory cells in special microvironments.