Herpes simplex virus-1 (HSV-1) is a major pathogen that causes various central nervous system (CNS) diseases,including herpes simplex encephalitis and meningitis.According to recent studies,PNKP significantly affects the proliferation of HSV-1 in astrocytes.Here,we used viral proliferation curves to confirm the significant inhibitory effects of PNKP on HSV-1 proliferation.PNKP downregulation was also confirmed by analyzing the transcription of viral genes.We found that PNKP downregulation affects the viral DNA copy number.This study preliminarily confirms that PNKP affects viral proliferation by affecting HSV-1 genome cyclization.These results also suggest that astrocytes play a specific role in preventing HSV-1 infection.
Lei YueSujie GuoXia CaoYing ZhangLe SunLongding LiuMin YanQihan Li
We previously constructed a herpes simplex virus 1(HSV-1) UL7 mutant virus(M1) and showed that a partial deletion mutation of the UL7 gene led to a lower proliferative rate and an attenuated phenotype. Using the M1 mutant, we further modified the UL41 gene, which encodes another tegument protein, and the latency-associated transcript(LAT) gene. Observations of the resulting mutants with modified UL7 and UL41(M2) or UL7, UL41 and LAT(M3) genes indicated attenuated phenotypes, with lower proliferative ratios in various cells, non-lethal infections in mice and lower viral loads in nervous tissues compared with the wild-type strain. Furthermore, no LAT stable intron could be detected in the trigeminal ganglion of M3-infected animals. The results obtained with the three HSV-1 mutants indicate that the M3 mutant is an attenuated strain with low pathogenicity during both acute and latent infections. Together, the results support the use of the M3 mutant as a candidate for the development of an HSV-1 vaccine.
目的利用酵母双杂交技术筛选与人巨细胞病毒US28蛋白相互作用的宿主蛋白,可为研究US28蛋白的作用机制提供依据。方法构建p GBKT7-US28诱饵重组载体,检测其在酵母细胞中的表达和自激活作用,然后利用酵母双杂交系统筛选人脑文库中与US28相互作用的蛋白质。对获得的阳性克隆进行PCR鉴定、测序及序列比对分析,并通过酵母共转化实验再次确认蛋白的相互作用。结果 p GBKT7-US28在酵母中成功表达US28融合蛋白;酵母双杂交筛选并验证,获得了5个与US28蛋白相互作用的宿主蛋白。结论初步鉴定得到5个与US28相互作用的细胞蛋白,为探索US28蛋白的新功能以及揭示巨细胞病毒的致病机理和疾病治疗奠定基础。
Studies of herpes simplex virus type 1 （HSV-1） infection have shown that many known and unknown cellular molecules in- volved in viral proliferation are up-regulated following HSV-1 infection. In this study, using two-dimensional polyacrylamide gel electrophoresis, we found that the expression of the HSV-1 infection response repressive protein （HIRRP, GI 16552881） was up-regulated in human L02 cells infected with HSV-1. HIRRP, an unknown protein, was initially localized in the cytoplasm and then translocated into the nucleus of HSV-l-infected cells. Further analysis showed that HIRRP represses HSV-1 proliferation by inhibiting transcription of the viral genome by interacting with the cellular transcription factor, ATFS, via its N-terminal domain. ATF5 represses the transcription of many host genes but can also act as an activator of genes containing a specific motif. We found that ATF5 promotes the proliferation of HSV-1 via a potential mechanism by which ATF5 enhances the transcription of viral genes during the course of an HSV-1 infection; HIRRP then induces feedback repression of this tran- scription by interacting with ATFS.
Viral microRNAs are one component of the RNA interference phenomenon generated during viral infection. They were first identified in the Herpesviridae family, where they were found to regulate viral mRNA translation. In addition, prior work has suggested that Kaposi＇s sarcoma-associated herpesvirus （KSHV） is capable of regulating cellular gene transcription by miRNA. We demonstrate that a miRNA, hsvl-mir-H27, encoded within the genome of herpes simplex virus 1 （HSV-1）, targets the mRNA of the cellular transcriptional repressor Kelch-like 24 （KLHL24） that inhibits transcriptional efficiency of viral imme- diate-early and early genes. The viral miRNA is able to block the expression of KLHL24 in cells infected by HSV-1. Our dis- covery reveals an effective viral strategy for evading host cell defenses and supporting the efficient replication and prolifera- tion of HSV- 1.
