真菌不同接触方式对自然杀伤细胞表面受体表达的影响

The effect of different fungus stimuli on the expression of membrane receptors of natural killer cells

目的本研究通过Transwell隔离培养体系探讨烟曲霉菌、白色念珠菌的不同菌体形态及不同接触方式对脐血来源细胞因子诱导自然杀伤(NK)细胞表面受体表达的影响,揭示NK细胞抗真菌与抗肿瘤作用机制的异同。方法利用聚碳酯膜孔径0.4μm的Transwell隔离培养系统,将实验组分为直接混合培养组(即直接接触组)和隔离组(即间接接触组);将NK细胞与真菌(烟曲霉菌孢子或菌丝、白色念珠菌孢子或菌丝)、K562细胞按10∶1比例进行直接混合和隔离培养,每组3个重复孔;培养6 h后通过流式细胞仪检测各组NK细胞胞膜受体NKG2D、TLR2及CD94/NKG2A的表达。结果烟曲霉菌、白色念珠菌的孢子和菌丝的直接接触作用均可上调NK细胞表面受体TLR2的表达(P值均<0.05),但间接接触作用对TLR2的表达无影响(P值均>0.05),真菌的直接、间接接触作用对NKG2D、CD94/NKG2A的表达均无影响(P值均>0.05);与K562细胞的直接接触可上调NK细胞表面受体NKG2D的表达(P值<0.05),但对TLR2、CD94/NKG2A的表达无影响(P值均>0.05)。结论真菌可以直接接触作用的方式通过上调TLR2的表达激活NK细胞,这与肿瘤细胞激活NK细胞的方式不同;真菌及肿瘤细胞的刺激均对NK细胞胞膜受体CD94/NKG2A的表达无影响。

Objective To explore the effect of different stimuli and morphotypes of fungus （aspergillus fumigatus and candida albicans） on the expression of membrane receptors of natural killer （NK） cells derived from cord blood, and compare the differences of mechanism between anti-fungal and anti-tumor process induced by NK cells. Methods The experiments were divided into two groups： Transwell non-contact culture group （indirect-contact） and mixture culture group （direct-contact）. The ratio between NK cells and fungus/K562 ceils was 10： 1. The expression of NKG2D, TLR2 and CD94/ NKG2A were detected by flow cytometry after 6h of culture. Results The expression of TLR2 in fungus direct-contact group was significantly higher than that in control group （ P 〈 0.05 ）, while the fungus indirect-contact culture had no impact on TLR2 expression （P 〉 0.05）. However, the expression levels of NKG2D and CD94/NKG2A in both fungus direct-contact and indirect-contact groups had no change （P 〉 0.05）. The expression of NKG2D was significantly higher in K562 eells direct-contact group than that in control group （ P 〈 0.05 ）, while no differenees of TLR2 and CD94/NKG2A expressions were found （P 〉 0.05 ）. Conclusions Fungus could activate NK eells by up-regulating the expression of TLR2, which is different in tumor eells. Neither fungus nor tumor cells have effect on the expression of CD94/NKG2A.