Umeå researchers have mapped how the TBE virus infects the brain, causing encephalitis. The researchers developed a method to three-dimensionally determine the location of viruses in the brains of mice and determine which specific parts of the brain have been infected with the TBE virus. The method is based on data obtained from image analyses, which were combined with studies of gene expression in different cell types. The result can be seen as a “road map” of the virus in the brain.
It turned out that there was a big difference between the spread of the virus in the brains of mice with and without an innate immune response. The virus infects different areas of the brain depending on the mouse’s innate immune system. When the researchers zoomed in on the cells in the infected brain areas, they could see that the immune system not only affected the spread of the virus, but also changed which cell types were infected in the affected brain areas.
When the researchers zoomed in, they could see that in cases where the brain’s immune system could not be activated, the brain’s immune cells, called microglia, became infected. By the way, their job is to help prevent and eliminate infection. However, in mice that were able to activate the immune system in the brain, it was mainly the neurons that became infected.
It is already known that the innate immune system plays an important role in preventing the TBE virus from damaging the brain, but it has been unclear where and which cells they infect.
“This is an important piece of the puzzle that is now being put into place. The results highlight the importance of the immune system for those infected with TBE. We have also opened up new opportunities to study viruses that infect the brain with new imaging. Using the methods we have developed and combining them with gene expression analysis of individual cells,” says Anna Overby.
The tick-borne encephalitis virus, TBEV, is not only a big problem in Sweden, especially in tick-prone areas such as the Stockholm archipelago and the Malardalen region, but also a big problem in Central and Eastern Europe. The virus can cause severe brain infections that can cause long-term injuries. There is currently no curative treatment for TBE, but the most important measures are prevention of infection by avoiding tick bites and vaccination.
HT
Source: ANI