Development and immunological evaluation of a ferritin nanoparticle vaccine displaying chicken infectious anemia virus VP1-VP2 proteins

BACKGROUND: Chicken infectious anemia virus (CIAV) causes immunosuppression, aplastic anemia, and lymphoid atrophy in young chicks, causing major economic losses to the poultry industry. Vaccination is the primary strategy for disease control. This study aimed to develop a ferritin-based nanoparticle vaccine displaying CIAV VP1-VP2 proteins and evaluate its protective efficacy in chicks. RESULTS: Using the SpyTag003/SpyCatcher003 system, we expressed ferritin-SpyCatcher003 (SC-FN) in insect cells and SpyTag003-VP2-VP1Nd129 in E. coli, achieving in vitro assembly of FN-VP2-VP1Nd129 nanoparticles, which were confirmed by SDS-PAGE, Western blotting, and transmission electron microscopy. Two-week-old chicks immunized with the nanoparticle vaccine developed significantly higher CIAV-specific antibody levels compared to the control group. Following lethal challenge with CIAV Cux-1 strain, the vaccine group showed significantly higher hematocrit values and thymus indices (p < 0.001), and importantly, no viral nucleic acid was detected in their thymus tissues. CONCLUSIONS: We successfully constructed a ferritin nanoparticle-based antigen display system for CIAV. The vaccine induced robust humoral immunity, effectively protected against viral replication and clinical disease, and offers a promising new strategy for developing safe and effective subunit vaccines against CIAV.