Park Sung-Han, Bae Eun Hye, Park Sang Min, Park Jin Woo, Lim Mi Suk, Jung Yong-Tae
Department of Microbiology and Institute of Basic Science, Dankook University, Cheonan 330-714, Korea.
J Microbiol Biotechnol. 2008 Oct;18(10):1735-40.
Clone PERV-C (A3) env was isolated from the genomic DNA of domestic pig (Sus scrofa domesticus) in Korea to investigate the molecular properties of PERV-C. The nucleic acid homologies between the PERV-MSL (type C) reference and the PERV-C(A3) clone was 99% for env, but a single base pair deletion was found in the transmembrane (TM) region of the env open reading frame. To examine the functional characteristics of truncated PERV-C env, we constructed a replication-incompetent retroviral vector by replacing the env gene of the pCL-Eco retrovirus vector with PERV-C env. A retroviral vector bearing PERV-C/A chimeric envelopes was also created to complement the TM defect. Our results indicated that truncated PERV-C env was not infectious in human cells as expected. Interestingly, however, the vector with the PERV-C/A envelope was able to infect 293 cells. This observation suggests that recombination within PERV-C TM could render PERV-C infectious in humans. To further characterize PERV-C/A envelopes, we constructed an infectious molecular clone by using a PCR-based technique. This infectious molecular clone will be useful to examine more specific regions that are critical for human cell tropism.
为了研究猪内源性逆转录病毒C型（PERV-C）的分子特性，从韩国家猪（Sus scrofa domesticus）的基因组DNA中分离出克隆的PERV-C（A3）env。PERV-MSL（C型）参考序列与PERV-C（A3）克隆的env核酸同源性为99%，但在env开放阅读框的跨膜（TM）区域发现了一个单碱基对缺失。为了检测截短的PERV-C env的功能特性，我们通过用PERV-C env替换pCL-Eco逆转录病毒载体的env基因构建了一个无复制能力的逆转录病毒载体。还构建了一个携带PERV-C/A嵌合包膜的逆转录病毒载体来弥补TM缺陷。我们的结果表明，截短的PERV-C env正如预期的那样在人类细胞中没有感染性。然而，有趣的是，带有PERV-C/A包膜的载体能够感染293细胞。这一观察结果表明，PERV-C TM内的重组可能使PERV-C在人类中具有感染性。为了进一步表征PERV-C/A包膜，我们使用基于PCR的技术构建了一个感染性分子克隆。这个感染性分子克隆将有助于检测对人类细胞嗜性至关重要的更特定区域。
