Microglia are specialized macrophages, which function as an immune defense in the central nervous system. A recent scientific article reported microglia are the immune cells in the brain, which send signals to cells and receive signals from the periphery and from the gastrointestinal tract. The authors stated, “Microglial dysfunction has been implicated in the onset and progression of several neurodevelopmental and neurodegenerative diseases”. The New York Times reported an abnormal protein was found at the center of all gliomas (type of brain cancer), which caused brain tissue to stick together.

Immortal pathogens can infect immune cells, spread to the brain via infected macrophages or migration from the gastrointestinal tract, and generate abnormal proteins and a sticky environment. The two articles together suggest one or more immortal intracellular pathogens can infect the glial cells and other types of brain cells, which could explain the microglial dysfunction, the development of brain cancer, and the plaque and tangles of Alzheimer’s.

http://jem.rupress.org/content/216/1/41