Construction and immune evaluation of the recombinant duck adenovirus type 3 delivering capsid protein VP1 of the type 1 duck hepatitis virus

Figure 1. The strategy of recombinant virus construction and the characterization of rDAdV3-mNeonGreen-162/188/641. (A) The design of recombinant virus construction. (B) CPE and fluorescence were observed in infected cells. (C) The PCR was used to detect the replication ability of the recombinant virus. (D) The growth kinetic curve of rDAdV3-mNeonGreen-188 and DAdV3 CH-GD-12-2014 strain.

Figure 2. Characterization of rDAdV3-VP1-188. (A) CPE was observed in infected cells. (B) PCR was employed to assess the replication ability of the recombinant virus. (C) The expression of VP1 protein was detected by WB. (D) The growth kinetic curve of rDAdV3-VP1-188 and DAdV3 CH-GD-12-2014 strain. (E) Electron microscope image of virus particles of rDAdV3-VP1-188.

Figure 3. The animal experiment of vaccine efficacy. (A) Schematic diagram of animal experiments and animal operations for assessing vaccine efficacy: this figure provides an overview of the experimental setup, including the timeline and procedures involved in assessing the efficacy of the vaccine. (B) Antibody responses against DAdV3: this graph depicts the antibody responses against duck adenovirus type 3 (DAdV3) in the rDAdV3-VP1-188, DAdV3, and PBS (control) groups. (C) Antibody responses against DHAV1: similar to the previous graph, this one illustrates the antibody responses, but specifically against duck hepatitis A virus type 1 (DHAV1). It compares the antibody levels in the rDAdV3-VP1-188, DAdV3, and PBS groups.

Figure 4. The animal experiment on protective efficacy. (A) Schematic diagram of animal experiment and animal operations for protective efficacy. (B) Macroscopic appearance and histological images of liver and kidney in DAdV3 challenge groups (group 1–3). It presents macroscopic and histological images of the liver and kidneys in the DAdV3 challenge groups. (C) Macroscopic appearance and histological images of Liver and kidneys in DHAV1 challenge groups (group 4–6), and the control group (group 7). The grouping information is shown in Table 3.