背景:泡沫病毒(FVs)是独特的非致病性逆转录病毒,它们在宿主中潜伏了很长时间。因此,他们可能是安全的,有效的基因转移载体。在这项研究中,评估了FV与宿主细胞的相互作用以及FV潜伏感染的分子机制。
方法:我们使用原型FV(PFV)感染HT1080细胞,并使用PFV指示细胞系(PFVL)测量病毒滴度。感染48小时后,培养上清液(即,无细胞PFV颗粒)和转染的细胞(即,收集细胞相关的PFV颗粒)并与PFVL孵育。又过了48小时,荧光素酶活性用于测量病毒滴度。
结果:通过转录组学测序,我们发现PREBmRNA表达显著上调.此外,PREB过表达减少PFV复制,而内源性PREB敲低增加PFV复制。PREB与TasDNA结合和转录激活域相互作用,并干扰其与PFV长末端重复序列和内部启动子的结合,防止转录因子的募集,从而抑制Tas的反式激活功能。PREBC端329-418aa在抑制PFV复制中起主要作用;PREB也抑制牛FV复制。因此,PREB对FV复制具有广谱抑制作用。
结论:我们的结果表明PREB通过阻碍PFV的转录来抑制其复制。
Foamy viruses (FVs) are unique nonpathogenic retroviruses, which remain latent in the host for a long time. Therefore, they may be safe, effective gene transfer vectors. In this study, were assessed FV-host cell interactions and the molecular mechanisms underlying FV latent infection.
We used the prototype FV (PFV) to infect HT1080 cells and a PFV indicator cell line (PFVL) to measure virus titers. After 48 h of infection, the culture supernatant (i.e., cell-free PFV particles) and transfected cells (i.e., cell-associated PFV particles) were harvested and incubated with PFVL. After another 48 h, the luciferase activity was used to measure virus titers.
Through transcriptomics sequencing, we found that PREB mRNA expression was significantly upregulated. Moreover, PREB overexpression reduced PFV replication, whereas endogenous PREB knockdown increased PFV replication. PREB interacted with the Tas DNA-binding and transcriptional activation domains and interfered with its binding to the PFV long terminal repeat and internal promoter, preventing the recruitment of transcription factors and thereby inhibiting the transactivation function of Tas. PREB C-terminal 329-418 aa played a major role in inhibiting PFV replication; PREB also inhibited bovine FV replication. Therefore, PREB has a broad-spectrum inhibitory effect on FV replication.
Our results demonstrated that PREB inhibits PFV replication by impeding its transcription.