title: Temporal regulation of HTLV-2 expression in infected cell lines and patients: evidence for distinct expression kinetics with nuclear accumulation of APH-2 mRNA.
abstract: BACKGROUND
  Human T-cell leukemia virus types 1 and 2 (HTLV-1 and HTLV-2) are delta retroviruses with similar genetic organization. Although both viruses immortalize T-cells in vitro, they exhibit distinct pathogenic potential in vivo. To search for possible differences in its expression strategy with respect to HTLV-1, we investigated the pattern of HTLV-2 expression in infected cell lines and peripheral blood mononuclear cells (PBMCs) from infected patients using splice site-specific quantitative RT-PCR.
  
  
  RESULTS
  A novel alternative splice acceptor site for exon 2 was identified; its usage in env transcripts was found to be subtype-specific. Time-course analysis revealed a two-phase expression kinetics in an infected cell line and in PBMCs of two of the three patients examined; this pattern was reminiscent of HTLV-1. In addition, the minus-strand APH2 transcript was mainly detected in the nucleus, a feature that was similar to its HTLV-1 orthologue HBZ. In contrast to HTLV-1, expression of the mRNA encoding the main regulatory proteins Tax and Rex and that of the mRNAs encoding the p28 and truncated Rex inhibitors is skewed towards p28/truncated Rex inhibitors in HTLV-2.
  
  
  CONCLUSIONS
  Our data suggest a general converging pattern of expression of HTLV-2 and HTLV-1 and highlight peculiar differences in the expression of regulatory proteins that might influence the pathobiology of these viruses.
authors.affiliation: Department of Life and Reproduction Sciences, Section of Biology and Genetics, University of Verona, Verona, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Bender
authors.forename: Francesca
authors.initials: F
authors.lastname: Rende
authors.forename: Alessia
authors.initials: A
authors.lastname: Cotena
authors.forename: Paola
authors.initials: P
authors.lastname: Righi
authors.forename: Paola
authors.initials: P
authors.lastname: Ronzi
authors.forename: Ilaria
authors.initials: I
authors.lastname: Cavallari
authors.forename: Claudio
authors.initials: C
authors.lastname: Casoli
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Ciminale
authors.forename: Umberto
authors.initials: U
authors.lastname: Bertazzoni
mesh_terms: D002478:Cells, Cultured; D005260:Female; D015967:Gene Expression Regulation, Viral; D015368:Human T-lymphotropic virus 1 / Q000235:genetics* / Q000472:pathogenicity; D015367:Human T-lymphotropic virus 2 / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology; D008297:Male; D008875:Middle Aged; D012326:RNA Splicing; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism*
chemical_list: D012367:RNA, Viral