MAV-2-O replicates at a reduced rate in cells from the osteopetrosis resistant G-B1 chicken.
The replication of the avian osteopetrosis virus MAV-2-O was compared in chick embryo fibroblasts from two strains of chicken. These were G-B1 which is relatively resistant to MAV-2-O and CB which is susceptible. The production of MAV-2-O was delayed in G-B1 cells (compared with CB cells). The same result was observed after infection with Rous sarcoma viruses of subgroups B, C, and D. In addition, the transforming viruses induced foci on G-B1 fibroblasts 24 to 48 hours later than on CB fibroblasts. In G-B1 cells there was also a delayed kinetics of intracellular viral RNA production. Integrated and linear unintegrated MAV-2-O DNA species were also present in lower amounts in G-B1 than in CB fibroblasts at 3 days postinfection. In vivo studies confirmed the in vitro situation. There was a marked difference in the amount of virus present in the osteoid bone matrix and the osteocytic lacunae of osteopetrotic bones from susceptible and G-B1 chickens. In contrast to the bone lesions from susceptible animals, budding virus particles were not detectable in lesions from G-B1 chickens. There was no difference in the amount of virus in osteopetrotic and non-osteopetrotic bone of susceptible chickens suggesting that virus replication alone is not sufficient for induction of osteopetrosis and that an additional specific virus-cell interaction is required. The relative resistance of strain G-B1 may therefore, be a consequence of a reduced frequency of this interaction. Its basis may be the lower amount of integrated, as well as unintegrated, viral DNA.
D000818:Animals; D001842:Bone and Bones / Q000382:microbiology; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens / Q000382:microbiology*; D004279:DNA, Viral / Q000378:metabolism; D007113:Immunity, Innate; D008854:Microscopy, Electron; D010022:Osteopetrosis / Q000382:microbiology / Q000662:veterinary*; D011201:Poultry Diseases / Q000382:microbiology*; D012367:RNA, Viral / Q000096:biosynthesis; D012190:Retroviridae / Q000254:growth & development*; D013997:Time Factors; D014779:Virus Replication
D004279:DNA, Viral; D012367:RNA, Viral