Quantitative evaluation of the role of Epstein-Barr virus immediate-early protein BZLF1 in B-cell transformation
Quantitative evaluation of the role of Epstein-Barr virus immediate-early protein BZLF1 in B-cell transformation
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DOI：
10.1099/vir.0.012831-0
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发表时间：
2009-10-01
影响因子：
3.8
通讯作者：
Takada, Kenzo
中科院分区：
文献类型：
--
作者：
Katsumura, Koichi Ricardo;Maruo, Seiji;Takada, Kenzo
eb病毒（EBV）即刻早期反激活子BZLF1通过刺激裂解基因级联表达，在将EBV感染从潜伏型转化为裂解型的过程中起关键作用；它还调节几种细胞基因的表达。最近，我们报道了BZLF1在EBV感染后早期在人原代B细胞中表达。为了研究感染后早期BZLF1的表达是否在EBV诱导的原代B细胞的生长转化中起作用，我们产生了敲除BZLF1的EBV，并将其与野生型EBV的转化能力进行了定量评估。我们发现，BZLF1基因敲除EBV的50%转化剂量与野生型EBV非常相似。携带bzlf1敲除EBV的已建立淋巴母细胞样细胞系（LCLs）与携带野生型EBV的LCLs在其潜在基因表达模式和体外生长方面没有区别。此外，携带bzlf1敲除型EBV的lcl和携带野生型EBV的lcl中，EBV发作的拷贝数非常相似。这些数据表明，在EBV基因组背景下破坏BZLF1的表达，以及由此导致的无法进入裂解复制，对lcl的生长和已建立的lcl中EBV发作的稳态拷贝数几乎没有影响。
The Epstein-Barr virus (EBV) immediate-early transactivator BZLF1 plays a key role in switching EBV infection from the latent to the lytic form by stimulating the expression cascade of lytic genes; it also regulates the expression of several cellular genes. Recently, we reported that BZLF1 is expressed in primary human B cells early after EBV infection. To investigate whether this BZLF1 expression early after infection plays a role in the EBV-induced growth transformation of primary B cells, we generated BZLF1-knockout EBV and quantitatively evaluated its transforming ability compared with that of wild-type EBV. We found that the 50% transforming dose of BZLF1 knockout EBV was quite similar to that of wild-type EBV. Established lymphoblastoid cell lines (LCLs) harbouring BZLF1-knockout EBV were indistinguishable from LCLs harbouring wild-type EBV in their pattern of latent gene expression and in their growth in vitro. Furthermore, the copy numbers of EBV episomes were very similar in the LCLs harbouring BZLF1-knockout EBV and in those harbouring wild-type EBV. These data indicate that disrupting BZLF1 expression in the context of the EBV genome, and the resultant inability to enter lytic replication, have little impact on the growth of LCLs and the steady-state copy number of EBV episomes in established LCLs.