Figure 4From: Construction of polycistronic baculovirus surface display vectors to express the PCV2 Cap(d41) protein and analysis of its immunogenicity in mice and swineOptimum conditions for production of the PCV2 Cap(d41) protein. Effects of different infection times, MOI, and cell numbers for expressing the Cap(d41) protein were tested. A, B Cell numbers (107) of Sf-9 cells were infected with MOI of 10 (A) or infected with different MOI (B) for 4 days. Cell numbers (107) of Sf-9 cells were infected with different recombinant baculoviruses as indicated. The Sf-9 cell alone and CE recombinant baculoviruses were used as the negative control. Signals in all western blots were quantified using Image J software. β-actin was used as an internal control for normalization. Relative abundance (%) are shown. The results were calculated from the data shown in the upper portion of each panel. All data shown represent the mean ± SD calculated from three independent experiments. A student t-test was conducted for analysis and a value of P < 0.05 was considered statistically significant. C Expression levels of the PCV2 Cap(d41) protein in different cell numbers infected with recombinant baculovirus at an MOI of 10 for 4 days was examined. Signals in all western blots were quantified using Image J software. β-actin was used as an internal control for normalization. Relative abundance (%) are shown. The results were calculated from the data shown in the left portion of each panel. All data shown represent the mean ± SD calculated from three independent experiments. A student t-test was conducted for analysis and a value of P < 0.05 was considered statistically significant. D The immune effect of different doses of Cap(d41) protein and evaluation of the effective dose. Different cell numbers (105, 106 and 107) of Sf-9 cells were infected with recombinant baculoviruses BacSC-Cap(d41) and BacDD-4Cap(d41), respectively, at an MOI of 10 for 3 days, respectively and cell lysates were collected to immunize mice. After two vaccinations, antibody titers were analyzed by ELISA. Data represent the mean ± SD. A p value less than 0.05 was considered significant.Back to article page