Genomic structure of HTLV (human T-cell leukemia virus): detection of defective genome and its amplification in MT-2 cells.
We studied the genomic structure of human T-cell leukemia virus (HTLV) in the HTLV producer cell line MT-2. Southern blotting revealed that at least eight HTLV proviruses were integrated in the chromosomes of MT-2 cells. The genomic structure of these proviruses was analyzed using fragments of cloned HTLV that were specific to gag, pol, env, pXs and U3R genes as probes. We have identified a complete genome of HTLV in MT-2 (non-defective type). However, seven of the eight proviruses had defective genomes. Provirus T2-a contains only the U3R (LTR) of HTLV and T2-b corresponds to the non-defective genome. T2-c possesses only a portion of env, and pXs and U3R. T2-d consists of gag, pol, part of env and U3R. On the other hand, T2-e, f, g and h consist of gag, pXs and U3R. Northern blotting experiments with mRNA from MT-2 cells supported the evidence of amplification of the gag-pXs gene of HTLV. 26S mRNA is considered to be a subgenomic species of 35S RNA. 32S mRNA may represent the T2-d provirus which lacks a portion of env and pXs, while 20S mRNA was a subgenomic species. The gag-pXs gene may correspond to 24S mRNA, the amount which was amplified in MT-2 cells.
D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics; D017977:Deltaretrovirus / Q000235:genetics*; D005784:Gene Amplification; D005814:Genes, Viral; D006801:Humans; D007938:Leukemia / Q000382:microbiology; D009693:Nucleic Acid Hybridization; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics
D004279:DNA, Viral; D012333:RNA, Messenger