Narrator: This is Science Today. In the first comprehensive analysis of the response of the blood-brain barrier to a bacterial pathogen, Dr. Victor Nizet of the University of California, San Diego, exposed an experimental blood-brain barrier to the pathogen Group B streptococcus, which is the leading cause of bacterial meningitis in newborn infants.
Nizet: We found that on exposure to Group B Strep , a very small subset, about 80 genes, were turned on in response to the bacterial pathogen. And this pattern of gene activation helped us to explain how the blood-brain barrier provides a first line of defense against bacterial infection, because when the blood-brain barrier recognizes the presence of the bacteria, it activates a coordinated set of genes, which all work together to recruit white blood cells to the site of infection and to stimulate the marrow to produce more white blood cells.
Narrator: For Science Today, I'm Larissa Branin.