The brain and spinal cord are highly protected treasures of the central nervous system, wrapped under three protective layers of meninges. The outermost layer, the dura mater, has leaky windows through ...

In mice, intestinal infections reshaped dural CD4+ T-cell populations and seeded the brain’s outer meningeal border with antigen-specific memory cells that persisted for months and mounted rapid recall responses to bloodborne antigens. Oral priming was associated with reduced Salmonella spread to the brain and modest cross-protection in an engineered shared-antigen Candida model, although the researchers could not definitively prove that dural CD4+ T cells alone caused the protection.