A joint venture from researchers from the Helmholtz-Centre for Infection Research (HZI) in Braunschweig, the Otto-von-Guericke-University in Magdeburg, and the Karolinska institute in Sweden have taken an in-depth look at the connection between flu infection and pneumonia. Their results, recently released in the scientific journal "PLoS One", have disproven a common theory about flu-like pneumonia.
Some viral infections trigger a decrease of immune cells in the blood – a so-called "lymphopenia". The reasons behind it and whether this is the case with influenza are unknown. To investigate the latter, HZI researchers infected mice with flu viruses and measured the amount of immune cells in the animal's blood every day. Some days later, flu-infected mice received a dosage of pneumonia bacteria usually harmless for healthy mice. While the flu-infected mice did develop a superinfection & subsequently died, surprisingly, they were not suffering from lymphopenia. The healthy, non-flu-infected mice defeated the bacteria successfully and recovered.
To discover whether a lack of immune cells encourages an infection with pneumonia bacteria in general, an artificial drug-induced lymphopenia was established in the mice. Without infecting these lymphopenic mice with flu viruses, they received pneumonia bacteria. Despite a severe lack of immune cells, the mice recovered completely.
With these results, the researchers could show that influenza facilitates and intensifies an infection from pneumonia bacteria, while disproving the common idea that this is caused by a lack of immune cells. "This result was an enormous surprise for us because it directly contradicts widespread assumptions", says Sabine Stegemann, researcher in the groups "Immune regulation" at the HZI and "Molecular Immunology" at the Otto-von-Guericke-University in Magdeburg.
"Now we want to understand the reasons for the increased susceptibility", says Matthias Gunzer, head of the group in Magdeburg. "It could be interplay of weakened mucous membranes and scavenger cells that induce ideal conditions for pneumonia bacteria to create a deadly lung infection. Another reason may be a reaction of the host immune system: It disables hyperactive flu-fighting immune cells to inhibit destruction of healthy lung tissue. "The immune system keeps itself under control and that makes it easy for pneumonia bacteria to infect the lung", says Gunzer.
Article: Stegemann S, Dahlberg S, Kröger A, Gereke M, Bruder D, et al. 2009 Increased Susceptibility for Superinfection with Streptococcus pneumoniae during Influenza Virus Infection Is Not Caused by TLR7-Mediated Lymphopenia. PLoS ONE 4(3): e4840. doi:10.1371/journal.pone.0004840
Dr. Bastian Dornbach | Helmholtz Association
Further reports about: > HZI > Infection > PLoS One > flu infection > flu virus > flu-infected mice > hyperactive flu-fighting > immune cell > immune system > lymphopenia > lymphopenic mice > non-flu-infected mice > pneumonia > pneumonia bacteria > superinfection > viral infection > viral infections trigger
How to construct a protein factory
19.09.2019 | Universität Bern
Quality Control in Cells
19.09.2019 | Universität Heidelberg
To process information, photons must interact. However, these tiny packets of light want nothing to do with each other, each passing by without altering the...
Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Hamburg and the European Molecular Biology Laboratory (EMBL) outstation in the city have developed a new method to watch biomolecules at work. This method dramatically simplifies starting enzymatic reactions by mixing a cocktail of small amounts of liquids with protein crystals. Determination of the protein structures at different times after mixing can be assembled into a time-lapse sequence that shows the molecular foundations of biology.
The functions of biomolecules are determined by their motions and structural changes. Yet it is a formidable challenge to understand these dynamic motions.
At the International Symposium on Automotive Lighting 2019 (ISAL) in Darmstadt from September 23 to 25, 2019, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of research and development services in the field of organic electronics, will present OLED light strips of any length with additional functionalities for the first time at booth no. 37.
Almost everyone is familiar with light strips for interior design. LED strips are available by the metre in DIY stores around the corner and are just as often...
Later during this century, around 2060, a paradigm shift in global energy consumption is expected: we will spend more energy for cooling than for heating....
Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Potsdam (both in Germany) and the University of Toronto (Canada) have pieced together a detailed time-lapse movie revealing all the major steps during the catalytic cycle of an enzyme. Surprisingly, the communication between the protein units is accomplished via a water-network akin to a string telephone. This communication is aligned with a ‘breathing’ motion, that is the expansion and contraction of the protein.
This time-lapse sequence of structures reveals dynamic motions as a fundamental element in the molecular foundations of biology.
19.09.2019 | Event News
10.09.2019 | Event News
04.09.2019 | Event News
19.09.2019 | Power and Electrical Engineering
19.09.2019 | Physics and Astronomy
19.09.2019 | Event News