心理应激对正常人外周血T淋巴细胞体外活化表面分子表达的作用

目的:探讨心理应激增加对感染的易感性的细胞和分子免疫学机理。方法:采用双荧光染色流式细胞分析法对20名健康大学生志愿者(男女各半)在应激前后进行外周血淋巴细胞免疫表型及T细胞体外丝裂原刺激早期活化抗原表达分析。连续一周期末考试被设定为心理应激。结果:免疫表型分析显示,应激前后CD2、CD3、CD4、CD8、CD19、CD20、CD16、CD56等淋巴细胞的表面分子阳性的细胞的百分比的差异无统计学显著性;与应激前的结果相比,应激后的T细胞在体外培养条件下多克隆刺激剂活化后CD69的表达明显降低,植物血凝素(phytohemagglutinin,PHA)组CD69⁺CD3⁺/CD3⁺的百分率由应激前的28.1±4.1降低到应激后的17.6±3.8,佛波醇酯(phorbol 12,13-dibutyrate,PDB)组CD69⁺CD3+/CD3⁺的百分率由应激前的80.7±6.8降至应激后的65.8±7.9,而在没有刺激剂作用的条件下,T细胞CD69表达率应激前后的差别无显著。结论:应激对免疫系统的影响并不在于改变外周血淋巴细胞各亚群的比例的层面上;心理应激能降低健康人T细胞体外活化的反应性,这可能与心理应激个体对感染的易感性增加有关。

Effects of psychological stress on in vitro expression of activated surface molecules on T cells of peripheral blood from healthy persons

AIM: To study cellular and molecular mechanism involved in increasing susceptibility of infection in psychological stress persons. METHODS: Comparative studies were performed with double staining and flow cytometry analysis on immunophenotyping and in vitro expression of early activating surface molecule CD69 in response to mitogens on T cells from peripheral blood of 20 healthy college student volunteers before and after psychological stress. A series of term final examinations was defined as psychological stress. RESULTS: Immunophenotyping analysis showed no statistically significant difference in the percentage of CD2, CD3, CD4, CD8, CD19, CD20, CD16 and CD56 positive lymphocyte populations before and after psychological stress. There was a statistically significant decrease in the in vitro expression of CD69 in response to polyclonal stimulators on the T cells from persons after psychological stress than those before psychological stress. The percentage of CD69 expression (CD69⁺CD3⁺/CD3⁺%) in response to PHA and PDB in the whole blood culture for 72 hours decreased respectively from 28.1±4.1 and 80.7±6.8 on the T cells obtained before psychological stress to 17.6±3.8 and 65.8±7.9 on those obtained after psychological stress, while there was no statistically significant difference between the CD69 expression rates without stimulators on the T cells obtained before and after psychological stress. CONCLUSIONS: The effects of psychological stress to immune system is not on the level of changing proportions of the sub-populations within peripheral blood lymphocytes. Psychological stress can decrease the activating response of T cells in healthy persons, which may be responsible for the increase of susceptibility to infection in the psychological stress persons.