Analyze Diet
Journal of virology1997; 71(7); 4929-4937; doi: 10.1128/JVI.71.7.4929-4937.1997

Localized sequence heterogeneity in the long terminal repeats of in vivo isolates of equine infectious anemia virus.

Abstract: The role of in vivo long terminal repeat (LTR) sequence variation of the lentivirus equine infectious anemia virus (EIAV) has not been explored. In this study, we investigated the heterogeneity found in the LTR sequences from seven EIAV-seropositive horses: three horses with clinical disease and four horses without any detectable signs of disease. LTR sequences were targeted in this study because the LTR U3 enhancer region of tissue culture-derived isolates has been identified as one of the few hypervariable regions of the EIAV genome. Furthermore, LTR variation may regulate EIAV expression in vivo. Both intra- and interanimal sequence variations were investigated. The intra-animal variation was low in seropositive, healthy horses (on average 0.44%). Intra-animal variation was consistently higher in clinically ill horses (0.99%), suggesting that greater numbers of quasispecies of EIAV are present when active virus replication is ongoing. Interanimal comparisons of consensus sequences generated from each horse demonstrated that the enhancer region is a hotspot of sequence variation in vivo. Thirty-seven of the 83 nucleotides that compose the U3 enhancer region were variable between the different in vivo-derived LTRs. The remainder of the LTR that was analyzed was more conserved, 8 of 195 nucleotide positions being variable. Results of electrophoretic mobility shift assays demonstrated that some nucleotide substitutions that occurred in the enhancer region eliminated or altered transcription factor binding motifs that are known to be important for EIAV LTR expression. These data suggested that the selective pressures exerted on the EIAV LTR enhancer sequences are different from those exerted on the remainder of the LTR. Our findings are consistent with the possibility that enhancer sequence hypervariability can alter expression of the virus in tissue macrophages and therefore contribute to clinical disease in infected horses.
Publication Date: 1997-07-01 PubMed ID: 9188555PubMed Central: PMC191723DOI: 10.1128/JVI.71.7.4929-4937.1997Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
  • Journal Article
  • Research Support
  • U.S. Gov't
  • P.H.S.

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research explores how variations in the long terminal repeat (LTR) sequence of the equine infectious anemia virus (EIAV) vary across healthy and clinically ill horses.

Study Objective and Methodology

  • The main aim of the research was to investigate the role of in vivo (within the body) LTR sequence variation of the lentivirus EIAV, a specific kind of virus which has not been previously studied in detail.
  • For the study, the researchers analyzed LTR sequences from seven EIAV-seropositive horses, that is, horses that tested positive for the virus. Out of these, three had clinical disease while four showed no detectable signs of illness.
  • The LTR U3 enhancer region of tissue culture-derived isolates was specifically targeted because it had previously been identified as a highly variable region of the EIAV genome.

Findings

  • Both intra- and inter-animal variation was examined. The researchers discovered that the intra-animal variation (variation within the same animal) was significantly lower in seropositive, healthy horses, with an average of 0.44%.
  • On the other hand, the intra-animal variation was significantly higher in clinically ill horses, at an average of 0.99%. The researchers inferred from this result that greater numbers of ‘quasispecies’ of EIAV are present when active virus replication is taking place.
  • Inter-animal comparisons of consensus sequences produced from each horse demonstrated that the enhancer region is a hotspot of sequence variation in vivo.
  • Furthermore, electrophoretic mobility shift assays demonstrated that some nucleotide substitutions occurring in the enhancer region eliminated or altered transcription factor binding motifs. These are known to be crucial for EIAV LTR expression.

Conclusions

  • The results suggested that the selective pressures exerted on the EIAV LTR enhancer sequences are different from those applied to the remainder of the LTR.
  • The researchers’ findings are consistent with the possibility that enhancer sequence hyper-variability can alter the expression of the virus in tissue macrophages (immune cells that rid the body of damaged cells), and thus, contribute to clinical disease in infected horses.

Cite This Article

APA
Maury W, Perryman S, Oaks JL, Seid BK, Crawford T, McGuire T, Carpenter S. (1997). Localized sequence heterogeneity in the long terminal repeats of in vivo isolates of equine infectious anemia virus. J Virol, 71(7), 4929-4937. https://doi.org/10.1128/JVI.71.7.4929-4937.1997

Publication

ISSN: 0022-538X
NlmUniqueID: 0113724
Country: United States
Language: English
Volume: 71
Issue: 7
Pages: 4929-4937

Researcher Affiliations

Maury, W
  • Department of Microbiology, University of South Dakota, Vermillion 57069, USA. wmaury@charlie.usd.edu
Perryman, S
    Oaks, J L
      Seid, B K
        Crawford, T
          McGuire, T
            Carpenter, S

              MeSH Terms

              • Animals
              • Base Sequence
              • Binding Sites
              • DNA, Viral
              • Enhancer Elements, Genetic
              • Equine Infectious Anemia / virology
              • Genetic Heterogeneity
              • Genetic Variation
              • Horses
              • Molecular Sequence Data
              • Polymerase Chain Reaction
              • Repetitive Sequences, Nucleic Acid
              • Sequence Homology, Nucleic Acid
              • Transcription Factors / metabolism

              Grant Funding

              • AI24291 / NIAID NIH HHS
              • AI30025 / NIAID NIH HHS
              • CA72063 / NCI NIH HHS

              References

              This article includes 58 references
              1. Nature. 1992 Aug 6;358(6386):495-9
                pubmed: 1641038
              2. J Clin Microbiol. 1996 Jun;34(6):1481-7
                pubmed: 8735102
              3. Biochemistry. 1992 Oct 6;31(39):9393-8
                pubmed: 1382590
              4. PCR Methods Appl. 1991 Aug;1(1):17-24
                pubmed: 1842916
              5. Eur J Pharmacol. 1993 Jan 26;231(1):61-8
                pubmed: 8383063
              6. J Virol. 1993 Apr;67(4):2064-74
                pubmed: 8383228
              7. J Virol. 1993 May;67(5):2592-600
                pubmed: 8386267
              8. Biochemistry. 1993 Jul 27;32(29):7559-67
                pubmed: 7687876
              9. AIDS. 1993 Jun;7(6):769-80
                pubmed: 8363755
              10. J Virol. 1993 Nov;67(11):6522-34
                pubmed: 8411355
              11. J Virol. 1993 Nov;67(11):6586-95
                pubmed: 8411361
              12. AIDS Res Hum Retroviruses. 1993 Oct;9(10):997-1006
                pubmed: 8280481
              13. Proc Natl Acad Sci U S A. 1994 Jan 18;91(2):549-53
                pubmed: 7507249
              14. J Gen Virol. 1994 Feb;75 ( Pt 2):425-9
                pubmed: 8113766
              15. Virology. 1994 Mar;199(2):323-30
                pubmed: 7510083
              16. J Virol. 1994 Apr;68(4):2777-80
                pubmed: 8139056
              17. J Virol. 1994 May;68(5):3163-74
                pubmed: 7908701
              18. J Virol. 1994 Jul;68(7):4514-24
                pubmed: 8207826
              19. J Gen Virol. 1994 Jul;75 ( Pt 7):1615-21
                pubmed: 8021592
              20. Virus Genes. 1994 Mar;8(2):115-23
                pubmed: 8073632
              21. J Virol. 1994 Oct;68(10):6270-9
                pubmed: 8083967
              22. J Gen Virol. 1995 Feb;76 ( Pt 2):333-45
                pubmed: 7531216
              23. J Virol. 1995 Apr;69(4):2031-7
                pubmed: 7884848
              24. J Infect Dis. 1995 Apr;171(4):797-804
                pubmed: 7706805
              25. J Virol. 1995 May;69(5):2881-8
                pubmed: 7707512
              26. J Gen Virol. 1995 Jun;76 ( Pt 6):1533-7
                pubmed: 7782784
              27. AIDS. 1995 Apr;9(4):345-9
                pubmed: 7794539
              28. J Virol. 1995 Aug;69(8):5087-94
                pubmed: 7541846
              29. Virology. 1995 Jul 10;210(2):302-13
                pubmed: 7542416
              30. Proc Natl Acad Sci U S A. 1995 Aug 1;92(16):7480-4
                pubmed: 7638216
              31. Natl Inst Anim Health Q (Tokyo). 1969 Spring;9(1):1-9
                pubmed: 4306393
              32. J Am Vet Med Assoc. 1979 Apr 1;174(7):727-33
                pubmed: 218920
              33. Methods Enzymol. 1983;101:582-98
                pubmed: 6888276
              34. Rev Infect Dis. 1985 Jan-Feb;7(1):83-8
                pubmed: 2984759
              35. Cell. 1986 Jun 6;45(5):637-48
                pubmed: 2423250
              36. J Virol. 1987 Mar;61(3):693-700
                pubmed: 3468264
              37. J Virol. 1987 Apr;61(4):1067-72
                pubmed: 3029400
              38. J Gen Virol. 1988 Mar;69 ( Pt 3):667-74
                pubmed: 3351480
              39. J Virol. 1988 Aug;62(8):3073-6
                pubmed: 2839723
              40. J Virol. 1988 Sep;62(9):3522-6
                pubmed: 2841502
              41. J Virol. 1989 Jun;63(6):2492-6
                pubmed: 2470916
              42. J Acquir Immune Defic Syndr. 1989;2(4):344-52
                pubmed: 2754611
              43. J Virol. 1989 Nov;63(11):4925-31
                pubmed: 2552171
              44. J Virol. 1990 Aug;64(8):3716-25
                pubmed: 2164593
              45. Nature. 1990 Oct 11;347(6293):522
                pubmed: 2215679
              46. J Virol. 1990 Dec;64(12):6221-33
                pubmed: 2123011
              47. J Virol. 1991 Mar;65(3):1605-10
                pubmed: 1847479
              48. J Virol. 1991 Apr;65(4):1952-9
                pubmed: 1705993
              49. Nucleic Acids Res. 1991 Feb 11;19(3):533-7
                pubmed: 1707165
              50. J Gen Virol. 1991 Aug;72 ( Pt 8):1893-903
                pubmed: 1651983
              51. J Virol. 1991 Nov;65(11):6242-51
                pubmed: 1717720
              52. J Mol Biol. 1992 Feb 5;223(3):595-600
                pubmed: 1371812
              53. Curr Top Microbiol Immunol. 1992;176:1-20
                pubmed: 1600747
              54. J Virol. 1992 Jul;66(7):4085-97
                pubmed: 1318398
              55. Virology. 1992 Jul;189(1):103-10
                pubmed: 1376536
              56. Trends Biochem Sci. 1995 Aug;20(8):324-5
                pubmed: 7667892
              57. AIDS. 1995 Jul;9(7):675-83
                pubmed: 7546410
              58. J Virol. 1992 Oct;66(10):5906-13
                pubmed: 1382143

              Citations

              This article has been cited 11 times.
              1. Wang HN, Rao D, Fu XQ, Hu MM, Dong JG. Equine infectious anemia virus in China.. Oncotarget 2018 Jan 2;9(1):1356-1364.
                doi: 10.18632/oncotarget.20381pubmed: 29416700google scholar: lookup
              2. Wang XF, Liu Q, Wang YH, Wang S, Chen J, Lin YZ, Ma J, Zhou JH, Wang X. Characterization of Equine Infectious Anemia Virus Long Terminal Repeat Quasispecies In Vitro and In Vivo.. J Virol 2018 Apr 15;92(8).
                doi: 10.1128/JVI.02150-17pubmed: 29386282google scholar: lookup
              3. Qi X, Wang X, Wang S, Lin Y, Jiang C, Ma J, Zhao L, Lv X, Shen R, Wang F, Kong X, Su Z, Zhou J. Genomic analysis of an effective lentiviral vaccine-attenuated equine infectious anemia virus vaccine EIAV FDDV13.. Virus Genes 2010 Aug;41(1):86-98.
                doi: 10.1007/s11262-010-0491-6pubmed: 20526660google scholar: lookup
              4. Wei L, Fan X, Lu X, Zhao L, Xiang W, Zhang X, Xue F, Shao Y, Shen R, Wang X. Genetic variation in the long terminal repeat associated with the transition of Chinese equine infectious anemia virus from virulence to avirulence.. Virus Genes 2009 Apr;38(2):285-8.
                doi: 10.1007/s11262-008-0317-ypubmed: 19130201google scholar: lookup
              5. Goffin V, Demonté D, Vanhulle C, de Walque S, de Launoit Y, Burny A, Collette Y, Van Lint C. Transcription factor binding sites in the pol gene intragenic regulatory region of HIV-1 are important for virus infectivity.. Nucleic Acids Res 2005;33(13):4285-310.
                doi: 10.1093/nar/gki720pubmed: 16061936google scholar: lookup
              6. Vicient CM, Kalendar R, Schulman AH. Variability, recombination, and mosaic evolution of the barley BARE-1 retrotransposon.. J Mol Evol 2005 Sep;61(3):275-91.
                doi: 10.1007/s00239-004-0168-7pubmed: 16034651google scholar: lookup
              7. Maury W, Thompson RJ, Jones Q, Bradley S, Denke T, Baccam P, Smazik M, Oaks JL. Evolution of the equine infectious anemia virus long terminal repeat during the alteration of cell tropism.. J Virol 2005 May;79(9):5653-64.
              8. Hines R, Sorensen BR, Shea MA, Maury W. PU.1 binding to ets motifs within the equine infectious anemia virus long terminal repeat (LTR) enhancer: regulation of LTR activity and virus replication in macrophages.. J Virol 2004 Apr;78(7):3407-18.
              9. Payne SL, Pei XF, Jia B, Fagerness A, Fuller FJ. Influence of long terminal repeat and env on the virulence phenotype of equine infectious anemia virus.. J Virol 2004 Mar;78(5):2478-85.
              10. Oaks JL, McGuire TC, Ulibarri C, Crawford TB. Equine infectious anemia virus is found in tissue macrophages during subclinical infection.. J Virol 1998 Sep;72(9):7263-9.
              11. Belshan M, Harris ME, Shoemaker AE, Hope TJ, Carpenter S. Biological characterization of Rev variation in equine infectious anemia virus.. J Virol 1998 May;72(5):4421-6.