内耳免疫反应中的细胞凋亡活性及其与FasL表达的相关性

Correlation of apoptotic activity with expressing level in the immune reaction process of inner ear

目的观察内耳免疫反应过程中是否存在细胞凋亡以及细胞凋亡活性与FasL表达相关性。方法16只雌性白色豚鼠,随机分为实验组与对照组,每组各8只。所有动物均先以钥孔虫戚血蓝蛋白全身免疫。然后,实验组再以相同抗原进行单侧内耳局部免疫,对照组则于单侧内耳注射等量磷酸盐缓冲生理盐水。3天后处死动物,取内耳免疫侧(或对照注射侧)耳蜗制备石蜡切片,脱氧核糖核苷酸末端转移酶介导的缺口末端标记技术检测内耳细胞凋亡活性,免疫组化法检测内耳FasL表达水平。结果实验组动物内耳Corti器毛细胞、血管纹的缘细胞和螺旋神经节细胞中存在阳性着色的凋亡细胞,对照组豚鼠内耳则否。实验组动物内耳Corti器、蜗管侧壁、螺旋神经节细胞FasL表达阳性,对照组则为阴性。结论内耳免疫反应可诱导局部细胞凋亡活性增高,FasL在此过程中可能发挥重要作用。

Objctive To investigate the apoptotic activity present in the tissues of inner ear undergoing immune reaction and its correlation with the expressing level of Fasl here. Methods Sixteen white female guinea pigs were randomly divided into two groups, with 8 in each group. All the animals in both groups were sensitized systematically with keyhoie limpet hemocyanin（KLH）at first. Then, the guinea pigs in treating group（TG） were locally immunized again with the same antigen, KLH, injected into the inner ear through its basal turn in one side and those in controlling （CG） were treated with phosphate buffered saline（PBS）locally in the same way as that for TG. three days late following the local immunizing, all the animals in both groups were sacrficed and tissue samples of cochlea were taken from the treated side of ear to prepare paraffin sections. Followed were the determination of apoptotic actvity in these tissues of inner ear assayed by terminal - deoxynucleotidyl transferase mediated nick end labeling（TUNEL） procedured and the expressing level of FasL tested by immunohistochemistry. Results TUNEL-positive cells were found in the immunized inner ear of animals in TG, mainly being the hair cells of Corti＇ s organ, the marginal cells in the stria vascuiaris and the cells of spiral ganglion , and FasL-positively stained cells were also seen in these sample of the same group, mainly being those of Corti＇ s organ, the lateral wall of cochlear duct and spiral ganglion cells, In contrast, negatiwe staining was determined in the treated inner ear of animals in CG with PBS, either for TUNEL or for FasL. Conclusion It is suggested from this study that an increased local apoptotic activity can be induced in the inner ear undergoing immune reaction and FasL may play a very important role in this pathological process.