title: Long terminal repeat sequences from virulent and attenuated equine infectious anemia virus demonstrate distinct promoter activities.
abstract: In the early 1970s, the Chinese Equine Infectious Anemia Virus (EIAV) vaccine, EIAV(DLA), was developed through successive passages of a wild-type virulent virus (EIAV(L)) in donkeys in vivo and then in donkey macrophages in vitro. EIAV attenuation and cell tropism adaptation are associated with changes in both envelope and long terminal repeat (LTR). However, specific LTR changes during Chinese EIAV attenuation have not been demonstrated. In this study, we compared LTR sequences from both virulent and attenuated EIAV strains and documented the diversities of LTR sequence from in vivo and in vitro infections. We found that EIAV LTRs of virulent strains were homologous, while EIAV vaccine have variable LTRs. Interestingly, experimental inoculation of EIAV(DLA) into a horse resulted in a restriction of the LTR variation. Furthermore, LTRs from EIAV(DLA) showed higher Tat transactivated activity than LTRs from virulent strains. By using chimeric clones of wild-type LTR and vaccine LTR, the main difference of activity was mapped to the changes of R region, rather than U3 region.
authors.affiliation: Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou
authors.forename: Xiu-Fang
authors.initials: XF
authors.lastname: Yuan
authors.forename: Shao-Hua
authors.initials: SH
authors.lastname: Hou
authors.forename: Ya-Bin
authors.initials: YB
authors.lastname: Tu
authors.forename: Jin-Mei
authors.initials: JM
authors.lastname: Peng
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Wen
authors.forename: Hua-Ji
authors.initials: HJ
authors.lastname: Qiu
authors.forename: Dong-Lai
authors.initials: DL
authors.lastname: Wu
authors.forename: Huan-Chun
authors.initials: HC
authors.lastname: Chen
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Wang
authors.forename: Guang-Zhi
authors.initials: GZ
authors.lastname: Tong
mesh_terms: D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D018397:Equidae; D004859:Equine Infectious Anemia / Q000503:physiopathology / Q000821:virology; D015967:Gene Expression Regulation, Viral; D015756:Genes, tat; D014644:Genetic Variation; D006734:Horse Diseases / Q000503:physiopathology / Q000821:virology; D006736:Horses / Q000821:virology*; D004860:Infectious Anemia Virus, Equine / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D008264:Macrophages / Q000821:virology*; D008969:Molecular Sequence Data; D009000:Monocytes / Q000821:virology*; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D020079:Terminal Repeat Sequences / Q000235:genetics* / Q000502:physiology; D015533:Transcriptional Activation; D014765:Viral Vaccines
chemical_list: D014765:Viral Vaccines