According to a study first published in July of 2020 at The University of Virginia School of Medicine, more than 2 billion people have a brain parasite contracted from cats and contaminated meat. Yet, for most it goes undetected. The findings of the study could have a major impact on how we explain the body’s response to neurodegenerative disease, autoimmunity disorders and brain infections.
The research team at UVA discovered that it was due to the involvement of microglia that the parasite, Toxoplasma gondii, was controlled. As it turns out, the disease (toxoplasmosis), was kept in check so well because these microglia release a special molecule (IL-1a). This molecule supports immunity by recruiting cells outside the brain from the blood to be transported to the brain. So in healthy people, most never even realize they have a parasite.
Microglia are the brain’s primary defenders from foreign invaders. Microglia are the only immune cells inside the brain. What this study revealed was that the microglia could send for help when needed. This kind of response in theory could apply to all types of conditions that could include an immunological component such as neurodegenerative disease, MS, stroke and TBI (brain injury).
Tajie Harris, PhD, at UVA’s Department of Neuroscience and the interim director of the Center for Brain Immunology and Glia (BIG) said, “Microglia must die to save the brain from this infection. Otherwise the IL-1a remains stuck inside the microglia and wouldn’t alert the immune system that something is wrong.”
For decades the scientific community has thought differently about the relationship of the brain with the immune system of the body. The Department of Neuroscience and BIG Center has recently rewritten the book of this old understanding of this relationship. The information gained has shocked the scientific world and has sent into motion for research to move in another direction.
In one of the major areas of concern, was the role microglia play in defending the brain. In past years, research of microglia were always included with other immune cells throughout the body because of their close relationship to each other. This made it difficult to distinguish between the two types of defenders. Now that has changed.
What they found was that microglia burst to produce macrophages to help control any infections such as Toxoplasma gondii. This could explain why most people have no issues in controlling the parasite while others who may be immunocompromised become sick.
Samantha J. Batista a UVA researcher said, “ Understanding pathways like this could be beneficial for other diseases involving neuroinflammation. We can ask whether promoting this pathway is helpful in situations where you need more of an immune presence in the brain, such as infections or cancers, and also whether inhibiting this molecule could be helpful in diseases driven by too much neuroinflammation, like multiple sclerosis. Targeting one specific pathway like this could have less off-target effects than targeting inflammation more broadly.”
In the future, the research team is interested in learning more about how microglia detect parasites in the brain. For instance, from the remaining damaged brain tissue left as a result of many neuro-related disease. Or from directly searching for parasites within the brain.
UVS’s researcher, Harris, said, “The immune system must enter the brain to fight dangerous infections. We now understand how microglia sound the alarm to protect the brain. We suspect that similar signals are missed or misinterpreted in Alzheimer’s disease, opening up an exciting new research avenue in the lab.”
Our human body is marvelous in its ability to provide all the answers to any health crisis. The scientific struggle continues to be centered in unlocking new information by decoding what our biology is revealing from its symptoms. I’m always amazed at the wealth of knowledge scientists gain from looking deeper hidden within its structures, to piece together how different pathways interact that broaden their understanding of the body’s processes.
-A Balanced Brain is a Better Brain For a Happier Life-