許多病毒基因是可以影響細(xì)胞周期的,目前常用的方法是使用SV40 T抗原來(lái)誘導(dǎo)永生化。SV40 T抗原已被大量細(xì)胞驗(yàn)證是細(xì)胞永生化最簡(jiǎn)單有效的試劑,其機(jī)制相對(duì)容易理解。SV40(simian virus 40)是猿猴腎細(xì)胞病毒,SV40編碼兩種腫瘤抗原 (tumor antigen,T抗原),分別為大T抗原和小T抗原。T抗原的作用是:①大T抗原為細(xì)胞轉(zhuǎn)化的啟動(dòng)所必需;②轉(zhuǎn)化細(xì)胞表型的維持必需要有大T抗原的連續(xù)表達(dá);③小T抗原對(duì)于細(xì)胞的轉(zhuǎn)化不是必需的,但可起加強(qiáng)作用。因此,SV40 Large T 能使細(xì)胞進(jìn)入永生化的增殖狀態(tài),缺點(diǎn)是存在潛在的致癌風(fēng)險(xiǎn),可能引起細(xì)胞惡性轉(zhuǎn)化。(如中喬新舟:貨號(hào):ZQ1099 名稱(chēng)是huvec-Immortalized人臍靜脈內(nèi)皮細(xì)胞-永生化的細(xì)胞等)。下圖是CV40基因組DNA的構(gòu)成元件和永生化的進(jìn)程:
Figure 1. (a) Structure of SV40 genomic DNA is composed of three elements: the early and late coding units and the regulatory region. (b) Several domains and motifs make up the SV40 T antigens. (c) A brief overview of the process of SV40 induced immortalized transformation. (Ahuja D,2005)