Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


More than just a mechanical barrier – epithelial cells actively combat the flu virus


HZI researchers examine the way in which epithelial cells react to the flu virus in the lungs

Every year, we see new flu epidemics all over the world, which vary greatly in terms of their magnitude. Once it has entered the body, the influenza virus multiplies in the epithelial cells on the surfaces of the airways. Nevertheless, this does not go unnoticed and the body combats it actively. Alveolar type 2 epithelial cells can be found in the lower airways.

Influenza A virus-infected mouse epithelial cells. The nuclei of all cells are stained blue while infected cells are specifically marked using an influenza A virus nucleoprotein-specific antibody.

Copyright: HZI

For the first time, scientists from the Helmholtz Centre for Infection Research (HZI) in Braunschweig and the Otto von Guericke University Magdeburg have investigated the role which these play in the immune response in the lungs directly in the tissue of mice infected with flu. In doing so, they observed an unexpectedly strong and varied reaction. The scientists published their results in the professional magazine, "mBio".

Even this winter, many people were given first-hand experience of how the real flu is much more than just a normal cold. Although the current flu season has not fully subsided yet and we are still waiting for the final reports, we know that there was a particularly high number of flu infections with severe outcomes this year.

The remarkable thing here is that a lot of young people were affected in relative terms. Alongside additional visits to the doctor and hospital stays, which put a strain on both the patients and the health system, the flu even proved to be fatal in a few cases.

If a virus is transmitted from one person to the next, then it must multiply successfully in its new host in order to cause an infection. With the flu virus, influenza A, this happens in the cells of the human airways and the lungs.

Their surface is a thin and permeable barrier between the inside of the body and the environment – we refer to this as the epithelium. In severe cases of the flu, the virus penetrates right into the lower airways and uses the alveolar type 2 epithelial cells available there to multiply.

In the past, the role of the epithelium was reduced to a purely mechanical barrier function. However, studies in recent years have shown that the epithelial cells in the airways and lungs possess a multitude of functions which are key from an immunological point of view. What's more, they create an important link to the specific, adaptive immune system.

"The way in which the alveolar type 2 epithelial cells react to the flu virus represents a special case as it is precisely these cells which this virus uses to multiply," states Dr Sabine Stegemann-Koniszewski, a scientist in the immune regulation working group at the HZI and lead author of the study.

However, it is not easy for the virus to multiply as the epithelial cells actively defend themselves against the intruder. "We have seen that, on the one hand, they inhibit the multiplication of the virus and on the other hand, they protect neighbouring cells from penetration," explains Prof Dunja Bruder, head of the working group at the HZI and professor of infections immunology at the university hospital of the Otto von Guericke University Magdeburg.

"What's more, they attract additional immune cells to the infection site, activate these and therefore initiate additional steps towards an effective immune response." On top of this, the scientists were able to show that the alveolar type 2 epithelial cells respond to neurotransmitters which are sent out in turn by other immune cells as a reaction to the virus.

Previously, the way these cells react to influenza viruses had only been examined in cell cultures. "That has a cruical disadvantage – you do not see the interaction with other cells in the lungs," Bruder points out. Bruder and her colleagues have now successfully examined the reaction of these very epithelial cells in vivo – in other words, in a living organism – for the first time.

To do this, they infected mice with the virus and isolated alveolar type 2 epithelial cells on three consecutive days after the infection. This meant that they were able to observe when the cells reacted to the virus, the strength of this reaction, and what they used for the reaction.

"We observed a surprisingly strong, quick and varied reaction," explains Dr Andreas Jeron, the second author of the study. The cells react to the virus on the very first day after infection by activating different genes which are key for an immune response and by actively communicating with their environment to combat the virus.

On the one hand, these results underline the fact the alveolar type 2 epithelial cells are very much more than a mechanical barrier, even when you are infected with the flu virus. On the other hand, they provide important insights with regard to the immunological contribution that these cells make to combatting viruses, which was underestimated up until now. "The more we understand about how the very early response to the virus in the body actually works, the better we will be able to intervene and therefore help the body to combat a flu virus quickly and effectively," concludes Bruder.

Stegemann-Koniszewski S, Jeron A, Gereke M, Geffers R, Kröger A, Gunzer M, Bruder D. 2016. Alveolar type II epithelial cells contribute to the anti-influenza A virus response in the lung by integrating pathogen- and microenvironment-derived signals. mBio 7(3):e00276-16. doi:10.1128/mBio.00276-16. Link

Weitere Informationen: - Press Release

Susanne Thiele | Helmholtz-Zentrum für Infektionsforschung

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>