双歧杆菌脂磷壁酸对B16荷瘤小鼠NK细胞受体NKG2D及其配体的影响

目的探讨双歧杆菌脂磷壁酸（LTA）对黑色素瘤B16荷瘤小鼠NK细胞受体NKG2D及其配体的影响。方法将黑色素瘤B16细胞接种于C57BL／6小鼠皮下，待触及肿块后于荷瘤小鼠皮下注射双歧杆菌LTA。采用MTT、流式细胞术（FCM）、RT-PCR方法分别检测经双歧杆菌LTA处理后B16荷瘤小鼠NK细胞杀伤活性、NK细胞NKG2D受体蛋白表达以及肿瘤组织内Rae-1、H60 mRNA表达的变化。结果与对照组相比，经双歧杆菌LTA处理后，B16荷瘤小鼠的NK细胞杀伤活性增强（P〈0．05），NK细胞受体NKG2D表达明显增加（P〈0．05），肿瘤组织Rae-1、H60 mRNA表达上升（P〈0．05），并具有浓度依赖性。结论双歧杆菌LTA能够增强B16荷瘤小鼠NK细胞的杀伤活性，其机制可能与上调NK细胞受体NKG2D的蛋白表达和肿瘤组织Rae-1、H60 mRNA的表达有关。

Effect of lipoteichoic acid of Bifutobacterium on NKG2D receptor and its ligands of NK ceil in mouse bearing B16 cancer

Objective To explore the effect of lipoteichoic acid （LTA） of Bifutobacterium on NKG2D receptor and its ligands of NK cell in mice bearing melanoma B16 cancer. Methods Melanoma B16 cells were subcutaneously injected into C57BL/6 mice;LTA of Bifidobacterium was injected subcutaneously into the mice when the tumor was palpable. The changes of the killing activity of NK cells were detected by MTT assay;the expression of NKG2D protein in splenic NK cell and the mRNA expression of Rae-1 and H60 in tumor tissue were detected by flow cytometry （ FCM ） and RT-PCR respectively. Results Compared with the control group,the killing activity of NK cell,the expression of NKG2D protein in NK cells and Rae-1 , H60 mRNA expression in the tumour tissue were enhanced （ P 〈 0.05 ） in dose-dependent manner after treatment with different dose of LTA of Bifidobacterium. Conclusions LTA of Bifidobacterium can enhance the killing activity of NK cells in mice bearing melanoma B16 cancer. The mechanism is possibly correlated to the up-regulated expression of NKG2P protein in NK cells and the mRNA expressions of Rae-1 and H60 in tumor tissue.