乳鼠角朊细胞分离表达共刺激分子CD80/CD86

Neonatal Murine Keratinocytes Split Express CD80/CD86 upon Culture

以往研究认为角朊细胞不表达共刺激分子CD80 / CD86 ,无法提供淋巴细胞增殖过程中关键的共刺激信号,但培养的角朊细胞膜片移植后,最终供者细胞被完全排斥,具体机理不明。本实验使用近交系小鼠,有和无血清两种体系培养角朊细胞1、4、7d,采用流式细胞技术、激光共聚焦技术,RT- PCR方法检测角朊细胞在培养过程中MHC I类、II类抗原,及CD80、CD86的表达。证实培养的细胞中不含郎格罕氏细胞,首次发现乳鼠角朊细胞在培养过程中表达CD80 ,但不表达CD86 ,可刺激异基因淋巴细胞增殖,执行抗原递呈细胞功能。本研究结果为角朊细胞膜片移植排斥提出另一种可能的解释:MHC I/ II类分子和CD80的表达,使培养的异体角朊细胞兼具外来抗原和抗原递呈细胞的功能,刺激受体淋巴细胞增殖,参与排斥反应。

It was previously thought that keratinocytes did not express the CD80 and CD86 which provide the most important costimulatory signals for the antigen-specific T-cell activation. The cultured keratinocytes allografts were initially accepted, but eventually, all grafted donor ceils were gradually replaced by recipient ceils. The precise mechanisms are not very clear. In this study, neonatal murine keratinocytes were cultured for 7 days, the results of flow cytometry and confocal microscopy showed that CD80 could be detected on keratinocytes, while CD86 could not be detected all the time. RT-PCR analysis confirmed this result. The expression level of the CD80 mRNA amplified significantly from day 1 to day 7,as expression of the control β-actin, but CD86 was not detected, Mixed Lymphocyte Reaction （MLR） showed that keratinocytes cultured with 10% serum for 7 d stimulated effectively allogeneic rather than syngeneic T ceil proliferation. This study demonstrated for the first time that costimulatory molecule CD80 can be expressed on keratinocytes in vitro. These data provided an alternative explanation for the ultimate rejection of allogeneic keratinocytes in which keratinocytes act as antigen-presenting ceils.