en 23626875 Background: Infectious Bursal Disease Virus (IBDV) causes a highly immunosuppressive disease in chickens and is a pathogen of major economic importance to the poultry industry worldwide. The VP2 protein is the major host-protective immunogen of IBDV and has been considered as a potential subunit vaccine against the disease. VP2 coding sequence was cloned in an inducible fungal vector and the protein was expressed in Aspergillus niger (A. niger). Methods: Aiming at a high level of expression, a multicopy AMA1-pyrG-based episomal construct driven by a strong inducible promoter, glaA, was prepared and used in transformation of A. niger pyrG - protoplasts. SDS-PAGE and western blot analysis was carried out to confirm the expression of the protein. Results: A number of pyrG+ positive transformants were isolated and the presence of expression cassette was confirmed. Western blot analysis of one of these recombinant strains using monospecific anti-VP2 antibodies demonstrated the successful expression of the protein. The recombinant protein was also detected by serum obtained from immunized chicken. Conclusion: In the present study, we have generated a recombinant A. niger strain expressing VP2 protein intracellulary. This recombinant strain of A. niger may have potential applications in oral vaccination against IBDV in poultry industry. Aspergillus niger, Recombinant proteins, VP2 protein 35 41 https://www.ajmb.org/En/Article.aspx?id=107 https://www.ajmb.org/PDF/En/FullText/107.pdf MohammadAziziIndustrial and Environmental Biotechnology Department, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran456BagherYakhchaliIndustrial and Environmental Biotechnology Department, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran457AbdolrezaGhamarianMedical Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran459SomayehEnayatiMedical Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran460MahvashKhodabandehIndustrial and Environmental Biotechnology Department, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran461VahidKhalajMedical Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran135