Table 1.
Primers used for the amplification and sequencing in this study.
Figure 1.
Schematic diagram and the intracellular distribution patterns of the fusion protein in Sf21 cells.
(A) The polyhedrin fragments were genetically fused to the enhanced green fluorescent protein (EGFP) under the control of the polyhedrin promoter. Black shadowing corresponds to the basic residue cluster KRKK, and yellow shadowing corresponds to the mutative residue cluster NGNN. Subscript numbers refer to the polyhedrin amino acids fused to EGFP. (B) The fluorescence by EGFP was examined in Sf21 cells infected with viruses at 3 days post-infection. Cells were also stained to reveal the location of the nuclei (PI). Combining EGFP and PI staining revealed the intracellular location of EGFP (Merge). Protein localization was visualized using a confocal laser scanning microscope.
Figure 2.
Comparative analysis of fusion protein production.
Sf21 cells were infected at an MOI of 5 with each virus and harvested 4 days post-infection. Protein samples from the cells were analyzed by SDS-PAGE (A) and Western blot analysis with EGFP (B) and polyhedrin (C) antibodies.
Figure 3.
Fluorescence intensity of EGFP.
Sf21 cells were infected at an MOI of 5 with each virus and harvested 3 days post-infection. The fluorescence intensity of the cell extracts was measured using a fluorescence spectrometer (B). The bars indicate the mean ± SE (n = 3).
Figure 4.
Expression of CSFV E2 protein fused with partial polyhedrin.
Sf21 cells were infected at an MOI of 5 with each virus and harvested at 4 days post-infection. Protein samples were analyzed by SDS-PAGE (A) and Western blot analysis with E2 monoclonal antibody (B).
Figure 5.
Blocking rate of E2 antibodies induced in the sera of guinea pigs immunized with rAc-19-110-E2- ΔTMR.
Four guinea pigs were immunized with total cell extracts infected with rAc19-110-E2-ΔTMR and wild type AcMNPV for 4 weeks. The levels of E2-specific antibodies in the sera were measured using the IDEXX CSFV Ab Test Kit. The optical densities of the samples were measured at 450 nm using an ELISA microplate reader. The test samples were considered serologically positive when the blocking percentage was ≥40% (dotted line). The blocking percentages are expressed as the mean ± SE (n = 4).