- Scientists have discovered cells in the nose that stop flu reaching our lungs
- These cells, called Trms, protect against many strains of the virus
- Flu’s chameleon-like nature forces scientists to constantly make new vaccines
- Yet the Trm cells in the nose could ‘outwit the virus’, Melbourne scientists say
- Paves way for new vaccine providing long-term protection against all flu viruses Flu-fighting cells in the nose could lead to a one-shot flu vaccine offering protection for a lifetime.
Scientists have discovered a special long-lived white blood cell in the nose that could stop influenza from ever reaching our lungs.
Australian researchers have managed to stop the virus in its tracks through what scientists are calling a ‘nasal border patrol’.
Previous research into a universal vaccine has focused on the flu-busting powers of white blood cells in lung tissue, but these cells die too quickly to be useful in developing immunity.
Before, little was known about how the nasal border patrol works – but now a team from the University of Melbourne hope their breakthrough could help eradicate the highly contagious virus.
The findings could lead to a vaccine that provides long-term protection against all flu viruses
‘We took a step back and thought, ‘What if we could stop the virus in the nose before it made it to the lung?’, says Dr Linda Wakim, who specialises in microbiology and immunology.
‘We moved our focus to investigating immune responses in nasal tissue, which is where the body first encounters flu viruses – a kind of nasal border patrol.’
Flu is a major public health concern – worldwide it makes around three to five million severely ill and kills 250,000 to 500,000 people.
As well the health risks, seasonal outbreaks have a huge economic impact and experts have warned pandemics could even trigger a recession.
How they carried out the research
The researchers already knew that a particular type of white blood cell in the lungs – the resident memory CD8 T cells or Trms – are excellent at protecting against different strains of flu.
But they also knew that these cells in the lungs do not live very long – which has always taken the research back to square one.
‘Because they decayed so rapidly we would still have to constantly vaccinate the population,’ said Dr Angela Pizzolla, a research fellow at the university.
Then the team discovered that a population of these Trms live in nasal tissue which, and unlike their counterparts in the lung, can live for a very long time.
They found that a population of Trms cells in the lung drops at rate of 100,000 cells down to just 1,000 cells over a period of 100 days, whereas the Trms cell population in nose remains stable.
It finding paves the way for a vaccine that stimulates these Trms in the nose, halting specific strains of virus before it even enters the respiratory system.
‘We basically stopped influenza at the gates,’ says Dr Wakim.
Flu: The chameleon virus
The flu vaccine most people get each year works by stimulating white blood cells to produce the antibodies to fight a specific infection.
However, flu presents major challenges for scientists, as the viruses are constantly changing.
As the Melbourne team describe it, the flu virus is a ‘master of disguise’. It is expert at altering what it looks like on the surface, confusing our body’s immune system and prevent it from recognising the virus and fighting it off.
‘This is a big problem for influenza vaccine development,’ says Dr Wakim. ‘Our current flu vaccines work by training the body to recognise a component on the surface on an influenza virus particle.’
Because of its chameleon-like nature, scientists have to try play catch-up, reviewing vaccine composition each year to tailor them based on which strains are making people sick.
This is why we need to be vaccinated against influenza every year.
But Trms could change that, according to Dr Wakim.
‘Instead of recognising external parts of the virus, which are constantly changing, these cells are trained to recognise internal parts of the virus,’ she said.
‘These parts of the virus are equivalent to our internal organs.’
A vaccine triggering the power of the Trms cells in the nose – at the first site of infection – could be administered just once.
It would and provide long-term protection against any flu viruses you may encounter in your entire life – including any pandemic strains.
‘We are now trying to work out the best way to lodge these flu-fighting cells in the nasal tissue, with the ultimate goal of developing a new vaccine that can provide long-term protection against all flu viruses,’ added Dr Wakim.