实验室条件下人角质形成细胞的培养技术

背景:随着角质形成细胞体外培养技术的建立和发展,皮肤不再被认为是单纯的生理屏障,其在机体免疫和内分泌等方面尤为重要。目的:探讨实验室条件下人体角质形成细胞的培养技术,为角质形成细胞的多方面应用提供可靠的细胞来源。设计:开放性实验。单位:解放军第四军医大学西京医院临床免疫科和皮肤科。材料:实验于2003-03/2005-03在解放军第四军医大学西京医院临床免疫科实验室完成。选取同年4月西京医院泌尿外科门诊收治的1例6岁正常男性术后的包皮为角质形成细胞的来源。方法:①对表皮细胞分离过程采取两步消化法:首先运用离散酶对全层皮肤进行低温消化,将包皮皮片浸入质量浓度为2.5g/L的Dispase酶中,4℃过夜,次日分离表皮;第二步采用胰蛋白酶和乙二氨基四乙酸的混合液进行消化。②采用改良的无血清培养技术进行人体角质形成细胞的培养,培养基为人角质形成细胞无血清培养基 2.5mg/L牛垂体浸出液 5μg/L表皮生长因子 438mg/L谷氨酰胺,其中谷氨酰胺能促进角质形成细胞的生长。③将处于对数生长期的细胞进行人角质形成细胞的冻存和复苏,加入无血清培养基制成细胞悬液,调整细胞密度为5×105/mL接种入75cm培养瓶中传代培养。置于显微镜和透射电2镜下进行细胞形态观察。主要观察指标:①原代和传代细胞的生长情况。②不同代的角质形成细胞冻存和复苏情况。③角质形成细胞形态学观察结果。结果:①原代和传代细胞的生长情况:初期细胞悬于培养液中,逐渐细胞贴附于培养皿底部。一般在6～24h内开始贴壁,细胞以圆形为主,随着时间的延长伸展成椭圆型。3d左右可见数个角质形成细胞形成的小集落或小集簇,四周可见卫星样表皮细胞增殖,多数细胞为多角形,细胞的均质性和透明度加强。5d左右细胞融合范围可达70%,9d左右细胞融合达90%,11d左右细胞完全融合形成细胞膜片。角质形成细胞可在体外稳定培养2～3个月,细胞形态和生长速度无明显改变。②不同代的角质形成细胞冻存和复苏情况:将不同代的角质形成细胞分别冻存于液氮罐中,3个月后进行复苏,发现角质形成细胞的形态和生长速度无明显改变。③角质形成细胞形态学观察结果:显微镜下细胞呈典型上皮样特征,高核浆比例,细胞紧密排列,轮廓清楚折光性好。透射电镜下培养的表皮角质形成细胞胞浆内有大量束状张力丝和张力原纤维,可见线粒体和粗面内质网,胞质周边有短的突起,细胞间有桥粒相连等角化细胞所具有的特点。结论:培养的角质形成细胞在多次传代后仍能够保持正常的形态特征,提示改良的培养角质形成细胞的技术可为实验和临床提供可靠丰富的角质形成细胞来源。

Cultivating technique for human keratinocyte under laboratory condition

BACKGROUND: Along with the establishment and development of in vitro culture technique for human keratinocyte, skin would no longer be considered only as the physiological barrier, it's of important significance in immunity and endocrinology and so on.OBJECTIVE: To explore the experimental cultivating technique for human keratinocytes to provide reliable cell resource forthe appliance of keratinocytes in many ways.DESIGN: An opening study with keratinocytes as the subjects of the experiment.SETTING: Department of Immunology and Department of Dermatology,Xijing Hospital, Fourth Military Medical University of Chinese PLA MATERIALS: This experiment was carried out in the clinical laboratory of Department of Immunology of Xijing Hospital of the Fourth Military Medical University of Chinese PLA between March 2003 and March 2005.Prepuce sample was postoperatively obtained from a 6-year-old boy who was admitted to the department of urology surgery of Xijing hospital in April 2003, prepuce was used as the source for keratinocytes.METHODS: ①Two step digestion technique was used for the isolation of epidermal cells: Firstly the skin flap was digested with dispase of mass concentration of 2.5 g/L at 4 ℃ for overnight, followed by separating epidermis the next day; Secondly it was dipped in trypsin and EDTA mixture for subsequent digestion. ② Improved serum-free cultivating technology was applied to the culture of human keratinocytes. The culture medium is composed of human keratinocyte serum free culture medium +2.5 mg/L bovine pituitary lixivium +5 μg/L epidermal growth factor+438 mg/L glutamine, glutamine can promote the growth of the keratinocyte. ③Human keratinocyte in exponential phase were cryopreserved and rewarmed, then made into cell suspension with additional serum free medium, cells were incubated in culture bottle of 75 cm2 by density of 5×105/mL for subculture. Cell morphological changes were observed under microscope and transmission electron microscope.MAIN OUTCOME MEASURES: ① The growth of primary cells and passage cells. ② The cryopreservation and resuscitation of human keratinocyte from different passages. ③ Morphological observation of Keratinocytes RESULTS: ①The growing state of the primary cells and passage cells:cells suspended primarily and gradually adhered to bottom of the culture dish at about 6-24 hours, most of cells were round and gradually stretched to ellipse shape, at about day 3, some keratinocyte clones and clusters can be observed with satellite-like proliferating epidermal cells scattered around, most of them were polygon and cell homogeneity and transparency became strengthened. Cell fusion amount to 70% at around 5 days, reaching to 90% at day 9 and even completely fused into cell diaphragm at day 1 1. Keratinocyte cultured in vitro can survive 2-3 months without obvious changes in cell morphology and growth speed. ② The cryopreservation and resuscitation of human keratinocyte in different passages: Different passage keratinocytes were separately cryopreserved in liquid nitrogen pot and resuscitated 3 months later, the morphology and growth speed of keratinocytes did not change obviously. ③Morphological observation on Keratinocytes: Cells possess typical epidermal cell characteristics under microscope, displaying higher nucleus/plasma ratio, cells arranged closely with clear boundary and good refraction. Transmission electron microscope revealed that cultured epidermal keratinocyte possessed multiple keratinocyte characteristics, such as massive bundles of tonofibrilla in the plasma, clearly observed mitochondria and rough endoplasmic reticule, cytoplasm sticking out short prominence and cells were found connected by desmosome.CONCLUSION: Keratinocyte can keep its normal morphological characeristics during in vitro culture process by using improved cultivating technique, which can be taken as reliable and abundant cell resource for the experimental and clinical study of human keratinocytes.