Even attenuated bovine leukemia virus proviruses can be pathogenic in sheep.

A.-F. Florins, N. Gillet, Mathieu Boxus, P. Kerkhofs, R Kettmann, L. Willems

Research output: Contribution to journalArticlepeer-review


[en] Based on a reverse genetics approach, we previously reported that bovine leukemia virus (BLV) mutants harboring deletions in the accessory R3 and G4 genes persist at very low proviral loads and are unable to induce leukemia or lymphoma in sheep, indicating that these R3 and G4 gene sequences are required for pathogenesis. We now show that lymphoma can occur, albeit infrequently (1 case of 20) and after extended periods of latency (7 years). Direct sequencing and reinfection experiments demonstrated that lymphomagenesis was not due to the reversion of the mutant to the wild type. Similar observations with another type of attenuated mutant impaired in the transmembrane protein (TM) YXXL signaling motifs were made. We conclude that the R3 and G4 genes and the TM YXXL motifs are not strictly required for pathogenesis but that their integrity contributes to disease frequency and latency.
Original languageEnglish
JournalJournal of Virology
Issue number18
Publication statusPublished - 2007
Externally publishedYes


  • Sciences du vivant => Médecine vétérinaire santé animale
  • Sciences de la santé humaine => Oncologie
  • Amino Acid Motifs/genetics
  • Animals
  • Cattle
  • Cell Transformation, Viral/genetics
  • DNA Mutational Analysis
  • Enzootic Bovine Leukosis/genetics/virology
  • Leukemia Virus, Bovine/genetics/pathogenicity
  • Lymphoma/genetics/veterinary/virology
  • Membrane Proteins/genetics
  • Sequence Deletion
  • Sheep/virology
  • Sheep Diseases/genetics/virology
  • Time Factors
  • Viral Proteins/genetics
  • Virus Latency/genetics

Fingerprint Dive into the research topics of 'Even attenuated bovine leukemia virus proviruses can be pathogenic in sheep.'. Together they form a unique fingerprint.

Cite this