Collagen and noncollagen protein synthesis in chick limb bud cells infected with a virus that causes osteoblastoma

Infection of cultured stage 24 (day 4.5) chick limb cells (spot cultures) with myeloblastosis-associated virus 2-(osteo) (MAV-2(0)) produces cell density-dependent alterations of collagen and noncollagen protein synthesis over the course of 8 days in culture. Collagen synthesis in infected, low density cultures (100 k cells/spot) was maximal on day 4 and increased 12 fold compared with maximal values on days 5-6 for uninfected counterparts. The patterns of collagen synthesis were similar in uninfected or MAV-2(0)-infected cultures seeded at 200 (medium density) or 400 k cells (high density) per spot with peaks on days 5-6. Noncollagen protein synthesis (NCP) in infected, low density cultures was maximal on day 4 and increased 15.7 fold compared with maximal values on days 5-6 for uninfected counterparts. The patterns for NCP synthesis were similar for uninfected and MAV-2(0)-infected cultures seeded at medium density (peak on day 5). However, in MAV-2(0)-infected , high density cultures, NCP synthesis was maximal on day 4 and increased 2.9 fold compared with maximal values on days 5-6 for uninfected counterparts. Although kinetics of cell division and DNA synthesis were similar in uninfected and MAV-2(0)-infected limb bud cells, the virus may have diverse affects on different cell populations at the three cell densities employed in these experiments.