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Archive - Mar 12, 2012

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Epstein-Barr-Like Virus Infects and May Cause Cancer in Dogs

More than 90 percent of humans have antibodies to the Epstein-Barr virus (EBV). Best known for causing mononucleosis, or "the kissing disease," the virus has also been implicated in more serious conditions, including Hodgkin's, non-Hodgkin's, and Burkitt's lymphomas. Yet little is known about exactly how EBV triggers these diseases. Now a team of researchers from the University of Pennsylvania School of Veterinary Medicine and Penn's Perelman School of Medicine has the first evidence that an Epstein-Barr-like virus can infect and may also be responsible for causing lymphomas in man's best friend. The findings suggest that domestic dogs possess a similar biology to humans with respect to EBV infection. That could allow scientists to study dogs to help uncover the mechanisms by which EBV leads to cancer in certain people. "There are no large-animal spontaneous models of EBV infection and virus-associated disease, and most studies investigating viral disease are performed in non-human primates, which are very expensive," said Dr. Nicola Mason, senior author of the study and an assistant professor of medicine and pathobiology at Penn Vet. "Discovering that dogs can get infected with this virus like people do may provide us with a long-sought-after model for EBV-associated disease." Dr. Mason's team at Penn Vet included Drs. Shih-Hung Huang, Philip Kozak, Jessica Kim, George Habineza-Ndikuyeze, Charles Meade, Anita Gaurnier-Hausser, and Reema Patel. The team worked closely with Dr. Erle Robertson, professor of microbiology at the Perelman School of Medicine. Their work was published online on March 8, 2012 in the journal Virology. In humans, the Epstein-Barr virus infects B-cells. After an acute phase of infection, of which many people are not even aware, the virus goes into a latent phase.

New Results Could Lead to More Effective Drug Discovery for Cystic Fibrosis

A recent study led by Dr. Gergely Lukacs, a professor at McGill University's Faculty of Medicine, Department of Physiology, and published in the January 20, 2012 issue of Cell, has shown that restoring normal function to the mutant gene product responsible for cystic fibrosis (CF) requires correcting two distinct structural defects. This finding could point to more effective therapeutic strategies for CF in the future. CF, a fatal genetic disease that affects aqpproximately 60,000 people worldwide, is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), a membrane protein involved in ion and water transport across the cell surface. As such, CF is characterized by impaired chloride secretion, causing the accumulation of viscous mucus that may cause multiple organ dysfunctions, including recurrent lung infection. The most common mutation in CFTR, known as deltaF508, is caused by a single amino acid deletion and results in a misfolded version of CFTR that is retained within the cell and quickly degrades rather than being trafficked to the cell membrane where it would function as a chloride channel. In 2005, Dr. Lukacs and his lab suggested that the deltaF508 mutation effect is not restricted to the domain (the nucleotide binding domain 1, or NBD1, one of five building blocks of CFTR) where the deltaF508 is located. Specifically, his team found that the mutation destabilizes the NBD1 as well as the NBD2 architecture, suggesting that domain-domain interaction plays a critical role in both normal and pathological CFTR folding. Building on his team's previous work and using computer-generated models of CFTR, Dr. Lukacs and his team set out to determine whether it was possible to correct both NBD1 stability and the domain-domain interaction defect.