Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Breakthrough in understanding how deadly pneumococcus avoids immune defenses

13.11.2018

Scientists at the University of Liverpool have discovered a new and important function of a toxin produced by disease-causing bacteria that could have significant implications for future vaccine design.

Streptococcus pneumoniae (the pneumococcus) is a major cause of life-threatening invasive diseases such as pneumonia, septicaemia and meningitis, and is responsible for more than one million deaths every year.


Image shows the structure of the pneumolysin toxin made up of its four domains in different colors.

Credit: UoL

Key to its disease-causing success is the action of a potent toxin called pneumolysin, which works by creating 'holes' in the membranes of human cells, and either killing them directly or causing significant tissue damage.

Until now, scientists believed that the effects of pneumolysin resulted purely from the binding of the toxin to cholesterol in host cell membranes.

A new study published in Nature Microbiology, however, shows that pneumolysin can also bind directly to a host cell receptor on specialised immune cells to suppress the immune response.

The study was a collaboration between the Bacterial Pathogenesis and Immunity Group at the University's Institute of Infection and Global Health and the Department of Microbiology, Tumour and Cell Biology at the Karolinska Institute in Stockholm.

Using specialised in vitro experiments in human cells and in vivo studies in mice, the team has shown that pneumolysin can bind directly to a host cell receptor called Mannose Receptor C type-1 (MRC-1) on immune cells, including macrophages and dendritic cells, causing them to reduce their production of molecules that promote inflammation and protective immunity. The bacteria can then survive more easily in the airways, as inflammation and immune cell activity is suppressed.

Professor Aras Kadioglu, who led the study in Liverpool said: "This is really a key moment in our understanding of how the pneumococcus causes disease.

First of all, because it breaks a long-standing dogma that pneumolysin can only bind to cholesterol, indeed the identification of a host receptor for pneumolysin has been the holy grail in the field for many decades, and secondly, because it changes our understanding of how the pneumococcus uses its toxin to manipulate and alter our immune response to its advantage. I am very excited by the potential of these new findings."

Dr Daniel Neill who is a joint first author, added: "Understanding how bacteria are able to promote infection via toxin production will help scientists to develop new ways of combatting serious infectious diseases. Several vaccines in development contain detoxified pneumolysin and it is important that we further explore how the newly-described receptor-binding activity might influence the immune responses induced by such vaccination."

Nicola Frost | EurekAlert!
Further information:
https://news.liverpool.ac.uk/2018/11/12/breakthrough-in-understanding-how-deadly-pneumococcus-avoids-immune-defences/
http://dx.doi.org/10.1038/s41564-018-0280-x

More articles from Health and Medicine:

nachricht Researchers find trigger that turns strep infections into flesh-eating disease
19.02.2019 | Houston Methodist

nachricht Loss of identity in immune cells explained
18.02.2019 | Technische Universität München

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Light from a roll – hybrid OLED creates innovative and functional luminous surfaces

Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.

The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...

Im Focus: Regensburg physicists watch electron transfer in a single molecule

For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.

The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...

Im Focus: University of Konstanz gains new insights into the recent development of the human immune system

Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens

Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...

Im Focus: Transformation through Light

Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light

When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...

Im Focus: Famous “sandpile model” shown to move like a traveling sand dune

Researchers at IST Austria find new property of important physical model. Results published in PNAS

The so-called Abelian sandpile model has been studied by scientists for more than 30 years to better understand a physical phenomenon called self-organized...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Global Legal Hackathon at HAW Hamburg

11.02.2019 | Event News

The world of quantum chemistry meets in Heidelberg

30.01.2019 | Event News

Our digital society in 2040

16.01.2019 | Event News

 
Latest News

New therapeutic approach to combat African sleeping sickness

20.02.2019 | Life Sciences

Powering a pacemaker with a patient's heartbeat

20.02.2019 | Medical Engineering

The holy grail of nanowire production

20.02.2019 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>