cloning and expression of gumboro vp2 antigen in aspergillus niger

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.