深低温保存的角膜缘组织CD40的表达以及体外培养增生活性的研究

目的探讨深低温保存的角膜缘组织CD40的表达情况以及培养后增生活性的变化。方法取角膜移植术后角膜缘组织20例（20眼），其中10例新鲜组织直接进行体外培养，另10例经深低温冷冻保存后再进行体外培养，对比观察两组细胞生长情况，并用免疫组化方法检测CD40在二者的表达。结果新鲜角膜缘组织块接种后3d可见细胞贴壁生长，培养至6d时细胞基本形成单层；深低温保存角膜缘组织块接种后在7d可见细胞贴壁生长，培养至10d时细胞基本形成单层。CD40在两组角膜缘上皮基底细胞层均有着色，为棕褐色，在深低温保存角膜缘组织表达明显减弱。结论深低温保存的角膜缘组织具有良好的增生活性，利用深低温保存的角膜缘组织进行角膜缘干细胞移植可以降低移植排斥率。

Culture of cryopreserved human corneal limbal tissue and the expression of CD40 in vitro

Objective To investigate the change of proliferative characteristics of cultured stem cells caused by cryopreserved corneal limbus and fresh tissue and the expression of CD40 on them. Methods There were twenty pieces of corneal limbus tissue after the corneal transplantation. They were divided into eryopreserved group and h＇esh group and cultured respectively in vitro, observe the proliferating status of them and the expression of CD40 were evaluated by immunohistoehemieal staing. Results The corneal limbal epithelial cells began expanding within 7d after planted and formed monolayer at 10d in cryopreserved group. While in fresh group, the eorneal limbal epithelial cells began expanding within 3d after planted and formed monolayer at 6d. The expression of CD40 in cryopreserved group was weaker than that of fresh group （ P 〈 0. 01 ）. Conclusion Cryopreserved corneal limbus stem cells has proliferative characters. If we use it to perform corneal limhal stem cell transplantation,the rate of keratoplasty rejection will decrease.