Deadly Fungus That Causes Meningitis Can 'Shapeshift' To Enter Your Brain

Scientists have found a deadly fungus that can 'shapeshift' to fit its way into your brain.

According to a study, the pathogenic fungus Cryptococcus neoformans (C. neoformans) can change its shape to pass through the blood-brain barrier, a barrier that is used to block pathogens out of the brain.

Jessica Brown, a pathologist from the University of Utah, said that Her team is still working to understand the remarkable changes it goes through when it first enters the body. Brown is a co-author of the paper.

Cryptococcus Neoformans

C. neoformans are naturally occurring organisms that live on decaying wood and in bird droppings. The CDC states that if the fungus is inhaled, it can cause cryptococcal meningitis by infecting the lungs, as well as other organs like the brain.

The researchers discovered that the tiniest C. neoformans cells entered the brains of the mice they were studying and that this caused changes to the surfaces of these cells.

According to Brown, the Cryptococcus cells in the lungs are extremely diverse, coming in a variety of shapes and sizes. She was therefore shocked when her grad student showed her images of the uniformity of brain cells.

Seed Cells

According to research by Brown's team, extrapulmonary organ entry depends on the development of a small C. neoformans morphotype, also known as "seed" cells because of their propensity for colonization. In their study, they outlined how changes in cell size of the fungus and surface expression in seed cells lead to improved macrophage uptake.

According to Brown, the altered cell surface of these seed cells makes them more readily absorbable by macrophages or immune cells.

She said that macrophages take up invaders and try to sequester and eliminate them because they are in charge of containing them in some tissues.

The research team hypothesizes that seed cells take advantage of this propensity, and are transported into the organ by the macrophage more easily. If the conditions are perfect, as they are in the brain, the seed cells then escape and grow in the new organ environment.

Titan Cells

According to Brown, the first type of cells to form after a seed cell enters the brain are known as titan cells because they are enormous and have at least four times as much DNA as a "normal" C. neoformans cell.

Brown said that the seed cells that cause the infection give rise to these titan cells. They believe that the tiny cells that enter the brain, known as seed cells, do not develop when a larger cell shrinks.

The group instead proposes that seed cells develop over multiple generations: after receiving a signal, a normal or titan cell divides to create a new cell, but this time, instead of creating a cell exactly like it, it creates a seed cell. When the seed cells divide, they probably produce additional seed cells, Newsweek reports.