Influenzavirus A.

Researchers want to detect dangerous influenza viruses

Biotechnology and biochemistry Viruses Genes and genomes Enzymes and proteins
An international research team aim at finding biological markers for when the flu virus has the potential to jump from animals to humans.

What characteristics of viruses allow them to jump from animals to humans, and what types of viruses have the potential to trigger a worldwide pandemic, as happens with the coronavirus COVID-19. These are the questions a team of researchers led by the University of Copenhagen and researchers from DTU are trying to answer in a new research project Fluzoomark - “Viral and host factors of zoonotic and pandemic influenza A viruses”.

At the end of 2019, the project received a grant of almost DKK 60 million DKK from the Novo Nordisk Foundation, and the researchers are now preparing experimental models in the project. At DTU Bioengineering, senior scientist Kerstin Skovgaard is responsible for looking at which biological factors allow pigs to become infected with influenza viruses from humans, and what biological conditions in the individual species are important when pigs infect humans.

“We are particularly interested in pigs because their airways are similar to human airways. Today we already know that influenza virus in both pigs and humans penetrates the cells of the upper respiratory tract via the same receptors on the cell surface,” says Kerstin Skovgaard.

"By identifying and characterizing markers that are relevant to animal and human infection, we are significantly better prepared to curb upcoming influenza outbreaks in animals and humans."
Kerstin Skovgaard, Senior Researcher.

She points out that Danish pig production with an annual output of 30 million pigs is an industry where thousands of people are in daily contact with the animals. This makes Denmark an interesting place to study the development of new swine flu viruses.

Infection spread between animals and humans

At DTU, researchers will investigate biological material from pigs that are infected with human influenza and swine flu respectively. The goal is to map how the pigs' immune system responds to viruses and try to identify biological conditions necessary for viruses from pigs to infect humans and vice versa. The researchers will then identify the properties of the human immune system, which are also crucial for the spread of infection.

Professor Lars Erik Larsen from the Department of Veterinary and Animal Sciences at the University of Copenhagen, who has received the Novo Nordisk Foundation's grant, explains that the pilot project aims at providing new knowledge that makes it possible to apply a risk score to all viruses based on their potential for infection.

“Influenza A (H1N1) pdm09 virus has mutated extensively since 2009, and by looking at differences in infection patterns between ferrets, pigs and humans, we hope to identify the underlying causes of both virus and immune systems. The goal is to find out if some properties in pigs - unlike humans and ferrets - are prerequisites for successful infection,” says Lars Erik Larsen.

Increasing number of influenza subtypes in pigs

Once the researchers have identified markers of the potential for infection, they will try to make changes to the virus to remove the ability to infect humans.

Over the past 20 years, the number of influenza subtypes found when tested in Danish pig herds has increased significantly, including several subtypes with gene segments derived from human influenza. This indicates that there is a continuous infection from humans to animals.

"These human influenza viruses can exchange gene segments with swine flu subtypes and give rise to brand new strains with varying degrees of disease and the potential to create a pandemic. By identifying and characterizing markers that are relevant to animal and human infection, we are significantly better prepared to curb upcoming influenza outbreaks in animals and humans,” says Kerstin Skovgaard.