A white blood cell that normally removes bacteria from the bloodstream helps Escherichia coli (E. coli) accumulate in the blood and enter the brain resulting in the deadly infection known as meningitis.
Prasadarao V. Nemani, PhD, a scientist at The Saban Research Institute at Children Hospital Los Angeles plans to find out how this happens with a grant of $1.65 million from the National Institutes of Health – National Institute of Neurological Disorders and Strokes.
Meningitis is the inflammation of the covering of the brain and spinal cord. Bacterial meningitis can be serious, leaving about one third of those who survive with permanent neurological problems. Escherichia coli K1 meningitis is the most common infection of the central nervous system in newborns.
The disease occurs when bacteria replicate and eventually break through the protective “blood-brain barrier.” A single layer of endothelial cells, the blood-brain barrier normally prevents bacteria from entering the brain. The molecular mechanisms allowing this build-up of E. coli and its eventual invasion of the brain are not well understood. Nemani’s research implicates a type of white blood cell called a “macrophage.” Macrophages normally remove invading organisms from the blood.
“It is as if the macrophage turns traitor,” said Nemani, who also serves as an associate professor of infectious disease at Childrens Hospital Los Angeles. “Instead of protecting the body, it helps the bacteria survive in the blood and enter the brain. What causes the macrophage to change? When we figure that out, we have the basis for preventing the build-up of bacteria and preventing meningitis.”