Australian researchers have studied the link between severe respiratory infection and the development of asthma.

Severe viral respiratory infections in infants have been associated with a higher risk of developing asthma by the age of five.

Associate Professor Simon Phipps says that for the first time, scientists have been able to identify why that is.

“We have been able to show that young mice with a respiratory virus produce a cell messenger called prostaglandin 2 that actually makes it harder for their immune system to clear the viral infection,” he said.

“In our studies, the prostaglandin 2 messenger actually played a role in turning down the production of anti-viral proteins.

“We found that if we blocked the cell messenger prostaglandin 2 from reaching its target, the mice were able to clear the virus more quickly.”

Associate Professor Phipps said his group validated the findings by demonstrating that the levels of prostaglandin 2 were higher in the upper airways of babies hospitalised with the respiratory virus.

He said researchers then tested the cell messenger in the laboratory using human epithelial cells, which line the airway.

“When we infected the cells with the virus in the laboratory, it increased the enzyme that produces the cell messenger prostaglandin 2 and therefore increased the amount of prostaglandin 2 overall,” he said.

“When we blocked the ability of the cell messenger to reach its target, the virus was again able to be cleared more quickly.

“This particular type of cell messenger has been linked to driving allergic inflammation in asthma.

“Our research suggests that in addition to stopping the bad inflammation caused by the prostaglandin 2, blocking it also restores the immune system’s ability to fight a viral infection and reduces the risk of an asthma attack, which is often triggered by viral infection.”

Associate Professor Phipps said the findings could lead to new treatments that ward off the development of asthma.

“If we block this cell messenger from reaching its target, we now believe that infants will have a better chance of clearing the virus and rates of illness should reduce,” he said.

“We also believe that blocking it could help to reduce the risk of a child developing asthma later in life.”

The study was undertaken at QIMR Berghofer Medical Research Institute’s Respiratory Immunology laboratory in Brisbane.