“Meningitis”, a Big Threat to Brain Tissue – Institute
Meningitis is an inflammation of the membranes (meninges) surrounding your brain and spinal cord.
The swelling from meningitis typically triggers symptoms such as headache, fever and stiff neck.
According to the NINDS investigator, meningeal macrophages (shown in white, red, and blue) are on constant alert and infects the lining of the brain.
He said that the disease could leave its mark and would also affect the body’s ability to fight infections in the future.
He added that “the new study published in Nature Immunology reveals that infections can have long-lasting effects on a population of meningeal immune cells, replacing them with cells from outside the meninges that then change and become less likely to recognise and ward off future attacks.
“The research was supported by NINDS, part of the National Institute of Health (NIH).”
He explained that after infection, the immune cell landscape in the brain lining changes and brain lining immune cells that normally protect the brain from foreign invaders die and are replaced by cells from elsewhere in the body.
“These new cells are altered in a way that affects how they respond to subsequent challenges and new infections.”
According to him, one group of these macrophages is found along with blood vessels in the dura mater (the outermost layer of the meninges) and helps to catch pathogens from the blood before they reach brain tissue.
The blood vessels in the dura mater, McGavern said, were relatively open compared to the tightly sealed vessels found in other brain regions and macrophages in the dura mater, often served as the first line of defence against harmful blood-borne agents.
McGavern and his colleagues, using real-time imaging, took a detailed look at mouse meningeal macrophages, which are immune cells that live in the meninges, the protective layers covering the brain and spinal cord.
Consequently, the new macrophages are less responsive to this signal and have trouble quieting an infection-induced inflammatory response.
The result indicates that infections in the brain can have lasting effects, long after the virus leaves the system.
The findings suggest that in addition to identifying the type of infection, it may also be important to know if it is coming on the heels of an earlier bug because that may affect how the system responds.
Further studies are needed to learn about additional functions of meningeal macrophages and how these cells respond to other types of viruses and bacteria.