实验性矽肺大鼠外周血NK及NKT细胞动态变化及意义

Changes and Significance of NK and NKT Cells in Peripheral Blood at Different Stages in Silicotic Rat Model

[目的]研究实验性矽肺模型大鼠在染尘后的不同时间点外周血中自然杀伤细胞(NK)及自然杀伤T细胞(NKT)数量的变化,并探讨NK及NKT细胞与矽肺的相关性及临床意义。[方法]将48只健康雄性SD大鼠随机分成模型组和对照组,每组24只。模型组采用非暴露方式气管内一次性染尘(注入40mg/mL二氧化硅悬液1mL)建立大鼠矽肺模型,对照组采用相同方式气管内注入等量灭菌生理盐水。分别于染尘后第1、8、15、23、30、37天时处死模型组和对照组大鼠各4只,采集外周血,用流式细胞术检测大鼠外周血中NK(CD3-/CD161+)及NKT(CD3+/CD161+)细胞的百分率。[结果]模型组外周血NK细胞的水平在试验早期(第1天)开始上升,高于对照组(P<0.05),第23天达到高峰(P<0.01);之后有所下降,但依然高于对照组(P<0.05)。NKT细胞百分率在早期明显下降,后期慢慢回升,但仍低于对照组(P<0.05)。[结论]石英诱发了机体的固有性免疫应答,NK及NKT细胞参与了矽肺变化发展过程。

[ Objective ] To investigate the changes and significance of natural killer（ NK ）cells and natural killer T（ NKT ） cells in peripheral blood at different stages in silicotic rat model. [ Methods ] Forty-eight healthy male SD rats were randomly divided into silica exposed group and control group. One miniliter silica suspension（ 40mg/mL ）was administrated via intratracheal instillation at one time while equal amount of saline was instilled to the rats of control group. Animals were sacrificed at the day 1, 8, 15, 23, 30 and 37 after instillation, and the peripheral blood samples were collected. The levels of NK（ CD3-/CD161＋ ）and NKT （CD3＋/CD161＋） cells in peripheral blood were detected by flow cytometry. [ Results ]NK ceils in peripheral blood of silicotic rats started to increase on the first day after silica instillation （ P 〈 0.05 ）. The peak number of NK cells appeared at week 3, then began to decrease, but was still higher than that in the control group. NKT cells decreased（ P 〈 0.05 ）in the early stage obviously. The number of NKT cells increased later on, but was still lower than that in the control group. [ Conclusion ] Silica induces rat innate immune responses. NK and NKT cells play roles in the development of silicosis.