My laboratory is studying the molecular biology of economically important viruses of poultry and fish, and focuses on developing rational strategies for the diagnosis and control of viral infections.

Infectious Bursal Disease Virus (IBDV) and infectious pancreatic necrosis virus (IPNV) are pathogens of major economic importance to the poultry and fish industry. IBDV causes severe immunodeficiency in young chickens, whereas IPNV causes pancreatic necrosis in fish. To develop a safe, economical, and effective subunit vaccine for both IBDV and IPNV, we have cloned and expressed the structural proteins, encoded by the large genomic segment A, in a baculovirus insect-cell system.

Expression of these genes in insect cells resulted in the synthesis of IBDV or IPNV proteins that self-assembled to form "virus-like" particles. A single dose of this genetically engineered IBDV or IPNV vaccine supplied to susceptible host conferred active protection against challenge with respective viruses. We developed a system for generating infectious birnavirus by using synthetic transcripts derived from cloned cDNA. With this reverse genetics system, we are studying the function of IBDV and IPNV protein(s) in virulence, cell tropism, pathogenesis, and developing new generations of live attenuated, marked vaccines for IBDV and IPNV.

Another research project under way in my laboratory is the study of avian reovirus, which causes viral arthritis syndrome and malabsorption in chickens. To study the role of viral genes and proteins in the immune response and in pathogenesis, we have characterized the polypeptides of reovirus and have prepared a cDNA library of total genomic RNA. The complete nucleotide sequences of the major outer capsid protein genes have been determined. Work is in progress to characterize the other genomic segments of reovirus and to study the structure-function relationship of these genes.