Motility from self-antigens

Tcells get moving with a little self-stimulation, say Ursula Fischer, Elizabeth Ingulli (University of Minnesota, Minneapolis, MN), and colleagues. Interactions with self-ligands activate motility pathways in helper T cells, the new findings reveal.

Helper T cells hunt in the lymph nodes for just the right combination of antigen and its presenting MHC class II molecule (MHCII). But most of the time, they instead find self antigen-MHCII pairs that do not elicit T cell activation.

Fischer et al. investigated the role of these persistent self-interactions by studying mice that lack MHCII. They injected these mice with T cells carrying a receptor specific for an ovalbumin peptide. When the mice were then given normal dendritic cells presenting the ovalbumin antigen, the T cells were apathetic–they did not mount their normal immune...