[肝脏中自然杀伤细胞功能和数量的年龄相关变化：小鼠实验]

[Age-related changes of the function and amount of natural killer cells in the liver: experiment with mice].

作者信息

Zhao Peng, Bai Xue-feng, Yue Xin, Chi Qiang, Liu Jian-zhong, Hao Xi-shan

机构信息

Cancer Hospital affiliated to Tianjin Medical University, Tianjin 300060, China.

出版信息

Zhonghua Yi Xue Za Zhi. 2006 Jun 27;86(24):1710-3.

PMID:16854328

Abstract

OBJECTIVE

To investigate the age-related changes of the function and amount of natural killer (NK) cells in the liver.

METHODS

C57BL/6 mice aged 2 weeks and 8 weeks were killed and their livers and spleens were taken out. The percentages and absolute values of the NK cells in the livers and spleens were examined by flow cytometry. Using YAG-1 cells as the target cells, the cytotoxicity of the NK cells was detected. Using thymocytes of the homologous mice as the target cells, the cytotoxicity of the NK T cells was detected. The cytotoxicity of the cytotoxic T lymphocytes (CTLs) was detected with the EL-4 cells as the target cells. RT-PCR was used to detect the mRNA expression of perforin.

RESULTS

The NK cell percentage in the liver of the 2-week-old mice was 11.9% +/- 1.7%, not significantly different from that of the 8-week-old mice (9.9% +/- 1.6%, P > 0.05). The NK cell amount of per weight liver tissue of the 2-week-old mice was (11.6 +/- 2.5) x 10(5)/g, significantly higher than that of the 8-week-old mice, (3.4 +/- 0.8) x 10(5)/g, (P < 0.05). The cytotoxicity of the liver NK cells of the 2-week-old mice was 71.0% +/- 5.5%, significantly higher than that of 8-week-old mice (23.8% +/- 4.4%, P < 0.05). The cytotoxicity levels of the NK T cells and CTLs were not significantly different between the mice of different age. The cytotoxicity level of the spleen NK cells was not significantly different between the 2-week-old and 8-week-old mice as well. Phenotypic characterization showed that the NK cells in the liver of the 2-week-old mice were CD69(high) MAC-1(low) LY49C/1(low), whereas those in the liver of the 8-week-old mice were inverse, i.e., CD69(low) MAC-1(high) LY49C/1(high). The level of perforin mRNA was remarkably higher in the lever of the 2-week-old mice than in the liver of the 8-week-old mice.

CONCLUSION

The liver NK cells of the young mice have a higher level of cytotoxicity and a unique phenotype. The liver of young mice has its unique microenvironment and their liver NK cells have a special development pathway.

摘要

目的

研究肝脏中自然杀伤（NK）细胞功能和数量随年龄的变化。

方法

处死2周龄和8周龄的C57BL/6小鼠，取出其肝脏和脾脏。通过流式细胞术检测肝脏和脾脏中NK细胞的百分比和绝对值。以YAG-1细胞为靶细胞，检测NK细胞的细胞毒性。以同源小鼠的胸腺细胞为靶细胞，检测NK T细胞的细胞毒性。以EL-4细胞为靶细胞，检测细胞毒性T淋巴细胞（CTL）的细胞毒性。采用RT-PCR检测穿孔素的mRNA表达。

结果

2周龄小鼠肝脏中NK细胞百分比为11.9%±1.7%，与8周龄小鼠（9.9%±1.6%，P>0.05）相比无显著差异。2周龄小鼠每克肝脏组织中NK细胞数量为（11.6±2.5）×10⁵/g，显著高于8周龄小鼠（3.4±0.8）×10⁵/g（P<0.05）。2周龄小鼠肝脏NK细胞的细胞毒性为71.0%±5.5%，显著高于8周龄小鼠（23.8%±4.4%，P<0.05）。不同年龄小鼠的NK T细胞和CTL的细胞毒性水平无显著差异。2周龄和8周龄小鼠脾脏NK细胞的细胞毒性水平也无显著差异。表型特征显示，2周龄小鼠肝脏中的NK细胞为CD69（高）MAC-1（低）LY49C/1（低），而8周龄小鼠肝脏中的NK细胞则相反，即CD69（低）MAC-1（高）LY49C/1（高）。2周龄小鼠肝脏中穿孔素mRNA水平显著高于8周龄小鼠肝脏。