Sub-genomic RNA in Moloney leukemia virus grown in Iymphoid-derived cell lines consists primarily of homologous viral RNA

Abstract

Moloney murine leukemia virus (MoMuLV) grown in 2 lymphoid-derived murine cell lines (JLS-V9 and TB) contained 2 size classes of RNA subunits: 2.8 +/- 0.4 x 10(6) (n = 30) and 1.6 +/- 0.1 x 10(6) (n = 15) daltons. Detectable levels of low molecular weight viral RNA (LMW vRNA) were not present in MoMuLV grown in mouse embryo fibroblasts, nor rat cells, nor was it produced by them when they were infected with MoMuLV containing both species of vRNA. DNA probes complementary to both subunits were synthesized separately using purified reverse transcriptase (R.T.) and calf thymus DNA as primer. Polyadenylated LMW vRNA was selected and, by molecular hybridization was found to be completely homologous with the large RNA subunit. This was confirmed using cDNA probes representing defined regions of the genome. The LMW vRNA therefore contains multiple subsets of the viral RNA, which could correspond to multiple deletion mutants possibly generated by an efficient RNA splicing mechanism. In addition, low levels of non-homologous virus-like RNA were detected in MoMuLV grown in TB (2%) AND NIH/3T3 cells (0.4%).

Analysis of human blood monocyte activation at the level of gene expression. Expression of alpha interferon genes during activation of human monocytes by poly IC/LC and muramyl dipeptide.

“…Total cellular RNA was extracted from these cells by the guanidinium isothiocyanate/cesium chloride extraction method of Ullrich et al (25). Poly(A)enriched RNA was obtained by passing total RNA over oligo(dT) columns as previously described (26).…”

Biological and Molecular Biological Characterization of the Virus Progeny from Transformed Clones MuSV-124 and MuSV-349: Evidence for MuLV-specific Nucleotide Sequences in the MoMuSV Size Class of RNA from MoMuSV-124

“…The vRNA species were separated using the method of Howk et al (I978) as previously described (Ball et al 1979…”

“…The virus cDNA probe corresponding to the MoMuLV isolate (TBMoMuLV) was synthesized using detergent-disrupted virions as described (Rothenberg & Baltimore, 1976) in the presence of added calf thymus primer DNA. All other virus specific probes were synthesized by using purified virus RNA and avian myeloblastosis virus reverse transcriptase (a gift from Life Science Inc., St. Petersburg, Fla., U.S.A.) according to the method of Taylor et al (I976) and processed as described (Ball et al 1979). The cDNA probes had a specific activity of 1 x io 7 to 4 x xo 7 ct/min/#g.…”

“…1.6 x lO 6. The cDNA probe represented primarily the nucleotide sequences corresponding to the virus-like 30 SRNA (Ball et al 1979) and could be used to assess the level of homologous sequences present in the RNA preparations used in this study.…”