Brain-tethered T cells

On page 1805, Kawakami et al. show that antigen-specific CD4⁺ T cells that attack the brain become stationary within brain tissue, whereas nonspecific T cells cruise through without stopping. These intravital images—the first to capture T cells launching an autoimmune attack on the brain—suggest that antigen-specific T cells behave similarly in dense brain tissue as they do in lymph nodes.

Activated CD4⁺ T cells specific for the endogenous brain protein myelin basic protein (MBP) trigger fatal encephalomyelitis in a rat model of multiple sclerosis. These cells migrate into the central nervous system (CNS) where they become reactivated.

Previous studies by this group showed that both antigen-specific and nonspecific T cells gain access to the CNS, but only specific cells...