Insight

Spring 2008

Influenza studies may give clues

Avian influenza continues to raise concerns internationally for its potential to mutate, jump the species barrier, and cause an influenza pandemic in humans. While scientists are keeping a wary eye, a researcher at Colorado State University is investigating a similar species jump of influenza, but from horses to dogs rather than birds to people. Her work may give clues as to how influenza viruses are maintained in a new species, and help solve one of the many puzzles surrounding species specificity.

“In our laboratory, we are looking at the species specificity of the influenza virus,” said Dr. Gabriele Landolt, an Assistant Professor in the Department of Clinical Sciences. “Influenza viruses are occasionally able to cross species barriers to infect other species, but these infections are usually self-limiting and often result in only one person or animal getting infected. They rarely transmit this novel virus to others. In the case of canine influenza, we have a situation where an equine virus infected dogs and is now maintained in that species.”

Dr. Landolt has a grant from the Morris Animal Foundation (MAF) to study what allowed the equine virus to jump from horses to dogs, looking at the molecular factors that determine species specificity. Her Morris grant started in 2006.

“Since that time, we have been able to determine that the viruses isolated from horses and dogs are now two distinct lineages,” said Dr. Landolt. “Equine influenza successfully jumped the species barrier and we now have a new canine influenza sub-lineage that is maintained in the canine population of the United States.”Dr. Landolt said that the funding from MAF has helped her laboratory advance research, make connections with local shelters, and connect with other scientists conducting influenza work. The MAF grant has enabled her laboratory to develop a diagnostic test and offer it at no charge to area shelters to help diagnose and control respiratory disease outbreaks. In turn, she receives samples from the shelters to help in genetic characterization of canine influenza.

“The funds from Morris are allowing us to finish up this project and advance the field, and enabling us to apply to other funding agencies,” said Dr. Landolt. “The implications of our work are not only important for dogs, but also to understand which viral factors are important to allow influenza viruses to jump the species boundary, whether in dogs or in people. We feel that the canine model is an excellent opportunity to understand what appears to be a one-time, well-defined cross species event that led to the appearance of canine influenza, and apply that to human risk factors for influenza.”

Dr. Landolt, who is a large animal veterinarian at Colorado State University and virologist, looked at the receptors in the respiratory tract in dogs and found that they appear to be similar to those in the horse. She also is using reverse genetics to better understand the genetic characteristics of the canine virus. The work may one day help lead to greater understanding of how influenza viruses mutate and how such mutated viruses may be prevented from causing a global outbreak in the human population of a virulent strain of influenza.

The Morris Animal Foundation (MAF), is the nation’s largest non-profit funding organization of research benefiting companion animals and wildlife. This year, MAF is committed to spend $10 million to fund 120 health studies in 13 countries covering 35 species.