Wilson C A, Wong S, VanBrocklin M, Federspiel M J
Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20892, USA.
J Virol. 2000 Jan;74(1):49-56. doi: 10.1128/jvi.74.1.49-56.2000.
We previously reported that mitogenic activation of porcine peripheral blood mononuclear cells resulted in production of porcine endogenous retrovirus(es) (PERV[s]) capable of productively infecting human cells (C. Wilson et al., J. Virol. 72:3082-3087, 1998). We now extend that analysis to show that additional passage of isolated virus, named here PERV-NIH, through a human cell line yielded a viral population with a higher titer of infectious virus on human cells than the initial isolate. We show that in a single additional passage on a human cell line, the increase in infectivity for human cells is accounted for by selection against variants carrying pig-tropic envelope sequences (PERV-C) as well as by enrichment for replication-competent genomes. Sequence analysis of the envelope cDNA present in virions demonstrated that the envelope sequence of PERV-NIH is related to but distinct from previously reported PERV envelopes. The in vitro host range of PERV was studied in human primary cells and cell lines, as well as in cell lines from nonhuman primate and other species. This analysis reveals three patterns of susceptibility to infection among these host cells: (i) cells are resistant to infection in our assay; (ii) cells are infected by virus, as viral RNA is detected in the supernatant by reverse transcription-PCR, but the cells are not permissive to productive replication and spread; and (iii) cells are permissive to low-level productive replication. Certain cell lines were permissive for efficient productive infection and spread. These results may prove useful in designing appropriate animal models to assess the in vivo infectivity properties of PERV.
我们先前报道,猪外周血单个核细胞的有丝分裂原激活导致产生能够有效感染人类细胞的猪内源性逆转录病毒(PERV)(C. 威尔逊等人,《病毒学杂志》72:3082 - 3087,1998年)。我们现在扩展该分析,以表明命名为PERV - NIH的分离病毒在人细胞系中进一步传代后,产生了一个病毒群体,其在人细胞上的感染性病毒滴度高于初始分离株。我们表明,在人细胞系上再进行一次传代时,人细胞感染性的增加是由于对携带猪嗜性包膜序列(PERV - C)的变体进行选择以及对具有复制能力的基因组进行富集所致。对病毒粒子中存在的包膜cDNA进行序列分析表明,PERV - NIH的包膜序列与先前报道的PERV包膜相关但不同。在人原代细胞和细胞系以及非人灵长类和其他物种的细胞系中研究了PERV的体外宿主范围。该分析揭示了这些宿主细胞中三种感染易感性模式:(i)在我们的检测中细胞对感染具有抗性;(ii)细胞被病毒感染,因为通过逆转录 - PCR在上清液中检测到病毒RNA,但细胞不允许有效复制和传播;(iii)细胞允许低水平的有效复制。某些细胞系允许高效的有效感染和传播。这些结果可能有助于设计合适的动物模型来评估PERV的体内感染性特性。