SD大鼠老龄化过程中外周血及免疫细胞表型的性别差异研究

Gender differences in peripheral blood and immune cell phenotypes in aging Sprague-Dawley rats

目的比较分析不同月龄SD大鼠外周血和免疫器官的免疫细胞分型指标性别差异。方法选用12月龄SD大鼠和2月龄SD大鼠,雌雄各半,检测外周血细胞计数及分类、脏器指数、外周血和脾免疫细胞分型、脾T细胞P16表达量,并对结果进行性别差异比较。结果年轻大鼠的各项检测指标未见性别差异。外周血计数与分类结果显示,与青年大鼠比较,老年雌性大鼠白细胞下降;老年雄性大鼠和老年雌性大鼠红细胞上升,两项指标均具有性别差异;老年雄性大鼠和老年雌性大鼠均表现为中性粒百分比上升、淋巴细胞百分比下降、嗜酸性粒细胞百分比升高,未见性别差异;外周血其他指标未见明显改变。老年雌性大鼠胸腺指数低于老年雄性大鼠;老年雄性大鼠脾指数升高,并高于老年雌性大鼠。外周血免疫细胞流式分析结果显示,老年雌性大鼠辅助T细胞、调节T细胞和细胞毒性T细胞上升;老年雌性大鼠B细胞下降;老年雄性大鼠自然杀伤细胞升高;这几项指标均具有性别差异。脾淋巴细胞分型结果显示,老年雌性大鼠CD3+升高,CD45RA+下降。脾T细胞P16表达量老年大鼠P16均升高,未见性别差异。结论本研究各项指标在青年组大鼠未见性别差异,老年大鼠在外周血白细胞、红细胞计数,中性粒、单核细胞百分比;免疫脏器指数;免疫细胞分型分析中调节T细胞,细胞毒T细胞,自然杀伤细胞,B细胞,CD3阳性细胞等指标改变均存在性别差异。提示老年大鼠的免疫系统的内稳态(homeostasis)平衡失调,在老年性改变中的一些指标出现性别差异。本研究结果为研究老年疾病及衰老动物模型提供了性别对老龄化影响的基础数据。

Objective Gender differences in immune cell types in peripheral blood and spleen were compared between aged and young Sprague-Dawley rats.Methods Twelve-month and 2-month-old rats were used.Rats in each age group were half male and half female.Classification and counts of peripheral blood cells,organ index,peripheral blood and spleen immune cell typing,and P16 expression in spleen T cells were determined and the result compared with respect to age and gender differences.Results The peripheral blood leucocyte count was decreased in the aged female rats,and there was a gender difference.The erythrocyte count was increased in both aged male rats and aged female rats,but there was a difference between them.The neutrophil percentage was increased and the lymphocyte percentage was decreased in the aged male and female rats.The eosinophil percentage was increased in the aged male and female rats.The monocyte percentage in the aged female rats was lower than that in the aged male rats.No significant changes in other peripheral blood indices were found.The thymus index of the aged female rats was decreased and was lower than that of the aged male rats.The spleen index of the aged male rats was increased and was higher than that of the aged female rats.Peripheral blood immunophenotyping indicated that the percentages of T helper cells,regulatory T cells and cytotoxic T cells were increased in the aged female rats.The percentage of B cells was decreased in the aged female rats.The percentage of natural killer cells was increased in the aged male rats.Splenic lymphocyte typing showed that numbers of CD3+cells increased and CD45RA+cells decreased in aged female rats.P16 expression in splenic T cells increased in all aged rats,and no gender difference was observed.Conclusions No gender differences were found in the various indices among young rats.Some indices showed a gender difference in aged rats,including peripheral blood leucocyte count,erythrocyte count,neutrophil percentage,monocyte percentage,thymus index,spleen index,and immune cell typing for regulatory T cells,cytotoxic T cells,natural killer cells,B cells and CD3-positive cells.These result indicate altered immune system homeostasis in aged rats,leading to gender differences in some indices in aged rats.The present result provided basic data for studying the impact of gender on aging-related diseases and animal models of aging.