Expression of Feline Leukaemia Virus Antigens on Cat Lymphoma Cells: Kinetics of Biosynthesis
Journal of General Virology
Cultured feline lymphoma cells (FL-74), productively infected with a feline leukaemia virus (FeLV) were quantitatively examined with a radioimmune assay for cell membrane associated FeLV-p27 and total FeLV associated cell surface antigens (FeLV-CSA) using a monospecific antiserum and a broadly reactive antiserum respectively. The infected cells bound 5.6 × 105 anti-FeLV-p27 IgG molecules/cell, representing 40% of the total FeLV-CSA detected. The kinetics of synthesis of surface associated p27 and total FeLV-CSA was determined following their removal by treatment of intact cells with trypsin. Both p27 and the total FeLV-CSA population reappeared on the cell surface within 6 to 8 h following trypsin digestion. Antigen re-expression was blocked by cycloheximide but not by actinomycin D or cordycepin. The time course of antigen decay with these same antimetabolites indicated that the average turnover rate of cell surface p27 and FeLV-CSA was 6 to 8 h while the mRNAs which specify these antigens have a lifetime of at least 10 h. Virus production was blocked in less than 2 h by cycloheximide, and within 2 to 4 h by actinomycin D. Virus production continued at a reduced rate for at least 6 h in the presence of cordycepin. The difference in sensitivity to inhibitors of RNA synthesis of p27 and FeLV-CSA production (blocked in 9 to 10 h) and of virus production (blocked in 2 to 4 h) supports the proposition of two non-equilibrating pools of intracellular virus RNA molecules with different half-lives: one associated with polyribosomes, and another which becomes encapsulated in the completed virion.
O'Brien, Stephen J. and Charles W. Boone. 1977. "Expression of Feline Leukaemia Virus Antigens on Cat Lymphoma Cells: Kinetics of Biosynthesis." Journal of General Virology 35, (3): 511-523. doi:10.1099/0022-1317-35-3-511.