CD46 facilitates meningitis

Neisseria meningitidis is a human-specific bacterial pathogen that can cause bacterial dissemination from the nasopharyngeal mucosa to the blood and cerebrospinal fluid. Pili of N. meningitidis mediate binding of the bacteria to human host cells, but exactly how the bacterium crosses the epithelial barrier at the nasopharynx and the blood–brain barrier has been unclear. In the July 18 Science, Linda Johansson and colleagues at the Karolinska Institutet show that CD46 has a pivotal role in the interaction between meningococcal bacteria and the epithelial barrier of an infected organism (Science, 301:373-375, July 18, 2003).

Johansson et al. expressed human CD46 in transgenic mice and subsequently exposed them to N. meningitidis. They observed that human CD46 transgenic mice were susceptible to meningococcal disease because bacteria could cross the blood–brain barrier in these animals. In addition, they showed that development of disease was more efficient with piliated bacteria...