The Stability and Efficency of CPB Cells Were Acclimated for Virus Proliferation.

Background: Vaccinations are still the most effective means of preventing and controlling fish viral diseases, and cells are an important substrate for the production of a viral vaccine. Therefore, the rapid-stable growth and virus sensitivity of cells are urgently needed.

Methods: Chinese perch brain 100th passage (CPB p100) were acclimated in a low serum with 5% FBS L-15 for 50 passages, then transferred to 8% FBS L-15 for 150 passages. Additionally, the morphology and cell type of CPB 300th passage (CPB p300) cells were identified. We analyzed the transfection efficiency and virus sensitivity of CPB p300 cells, and then optimized the conditions of ISKNV, SCRV, and LMBV multiplication in CPB cells.

Results: CPB p300 cells were more homogeneous, and the spread diameter (20-30) µm in CPB p300 cells became the dominant population. The doubling time of CPB p300 was 1.5 times shorter than that of CPB p100.However, multiplication rate of CPB p300 was 1.37 times higher than CPB p100. CPB p300 cells were susceptible to ISKNV, SCRV, and LMBV, and the optimal conditions of ISKNV, SCRV, and LMBV multiplication were simultaneous incubation, 0.6 × 10 cells/cm and MOI = 0.1; infection at 48 h, 0.8 × 10 cells/cm and MOI = 0.01; simultaneous incubation, 0.7 × 10 cells/cm and MOI = 0.05, respectively. The time and economic costs of ISKNV, SCRV, and LMBV multiplication in CPB p300 cells were significantly reduced.

Conclusions: The acquisition of CPB p300 cells laid a good material foundation for the production of ISKNV, SCRV, and LMBV vaccines.