高温对小鼠胸腺和脾脏T细胞亚群的影响

Change of T Cells Subsets in Thymus and Spleen during Hyperthermia

目的 研究高温对小鼠胸腺和脾T细胞亚群变化的影响 ,探讨高温诱导小鼠免疫器官损伤及热耐受形成的机理。方法 BALB/c小鼠每天 41℃高温处理 1小时 ,连续应激 9天 ,每间隔 1天于高温处理后 4h取胸腺和脾脏 ,称重后制成单细胞悬液 ,用流式细胞术检测CD4CD8细胞亚群。结果 高温的第 3天开始小鼠胸腺重量明显减轻 ,脾脏重量在第 3、第 5天明显减轻。胸腺CD4+ CD8+ 亚群比例第 1、3天明显减少 ,第 5天后开始恢复 ,胸腺细胞CD4+ :CD8+ 比值第 1天明显增高 ,之后迅速下降 ,第 7天下降到最低 ,第 9天开始恢复。脾细胞CD4+ :CD8+ 比值第 1天也增高 ,第 3天下降到最低值 ,此后开始恢复。结论 高温使小鼠胸腺和脾细胞均受到损伤 ,未成熟的CD4+ CD8+ 胸腺细胞亚群减少是高温处理后小鼠胸腺萎缩的主要原因 ,高温处理后期小鼠胸腺和脾T细胞亚群比例恢复可能提示热耐受的形成。

Objective To study the relationship between the change of T cells subsets and the mechanism of thermotolerance formation during hyperthermia.Methods The mice were exposed to hyperthermia by hot air(41℃,relative humidity 70%) in a thermal chamber for 1h each day,and were killed after hyperthermia for 4h at every other day till the nineth day.After weighed,thymuses and spleens were collected as single cells.The T cell subsets were assayed by flow cytometry.Results During hyperthermia,the weight of thymus decreased from the third day,and the weight of spleen decreased at the third and fifth day.The CD4 +CD8 + thymocytes decreased at the first and third day,but increased from the fifth day.The CD4 +/CD8 + ratio in thymocytes increased in the first day,decreased from the third day, but increased again at the ninth day.The CD4 +/CD8 + ratio in splenic cells also increased at the first day,but decreased to the lowest at the third day.Conclusion Hyperthermia damaged thymocytes and spleen cells of mice.The weight of thymus decreased was mainly because of the decrease of CD4 +CD8 + thymocytes.The rates of thymocytes and splenic T cells recovering themselves during hyperthermia may suggests the formation of thermotolerance.