A graduate student at the Virginia-Maryland College of Veterinary Medicine at Virginia Tech is investigating how a virus responsible for significant economic losses in the swine industry causes disease and suppresses the immune system.
Nicholas Catanzaro, of Lewiston, New York, a Ph.D. student in the Department of Biomedical Sciences and Pathobiology, hopes that his research on porcine reproductive and respiratory syndrome virus (PRRSV) will eventually help scientists develop safer, better vaccines. He was recently awarded a two-year, $95,000 fellowship from the U.S. Department of Agriculture’s National Institute of Food and Agriculture for his research.
“This is one of the most economically devastating global swine pathogens and causes more than $600 million in economic losses in the United States alone each year,” Catanzaro said. “My fellowship looks at how the virus causes disease in pigs. That’s important because scientists are trying to make safer, more-effective vaccines for pigs against the virus.”
First discovered in 1987, PRRSV causes reproductive failures in pregnant sows and respiratory disease in young piglets. Although it has similarities to the Coronaviridae family of viruses, which include the deadly severe acute respiratory syndrome (SARS), it cannot spread from animals to humans and poses no food safety threat.
In recent years, a highly pathogenic strain of PRRSV has emerged in pig farms of southeast Asia, leading to high mortality rates and significant economic losses.
“Although there are several commercial vaccines available, they are generally effective against homologous strains but not very effective against heterologous strains — those strains that are genetically quite different from the vaccine strain,” said X.J. Meng, University Distinguished Professor of Molecular Virology and Catanzaro’s advisor. “If you look at the virus strains currently circulating in the field worldwide, many are genetically different from the one used to create the vaccine.”
According to Catanzaro, the high genetic diversity of the virus makes it difficult to develop a vaccine that will protect against genetically different strains that frequently emerge in the field.
His USDA fellowship research aims to better understand the molecular mechanism that causes the virus to suppress the immune system in order to lay the foundation for future vaccine development.
“Viruses are interesting because they are so small and yet very powerful,” he said. “We want to better understand how some of the proteins that the virus genome encodes can suppress the pig’s immune system and cause disease.”
Meng added that this work may prove invaluable to vaccine researchers.
“If Nick can better understand how the virus causes immunosuppression, then we may be able to create a better vaccine that allows the pig to fight the virus more effectively with its own immune system,” Meng said. “It’s much easier to devise a better vaccine once we know the basic biology of the virus.”
Catanzaro is the fifth researcher in the Meng laboratory to receive a federal grant to study viral diseases in recent years. The others are Adam Rogers, Christopher Overend, Shannon Matzinger, and Scott Kenney.
Before joining Meng’s research team, Catanzaro completed a bachelor’s degree in molecular genetics from the State University of New York at Fredonia in 2013. He first visited Virginia Tech during the summer of 2012 to participate in Research Experiences for Undergraduates, a 10-week summer program that introduced him to microbiology research at the university.
Meng’s lab studies the molecular mechanisms of viral replication and pathogenesis and develops vaccines against emerging, reemerging, and zoonotic viral diseases. In 2006, the lab invented the first USDA fully licensed vaccine against porcine circovirus-associated disease in pigs, which is now commercially available worldwide.