Gut-grabbing T cells trigger GVHD

Effector CD8⁺ T cells that cling to the intestine trigger graft-versus-host disease (GVHD), according to El-Asady and colleagues on page 1647. By contrast, effector T cells that pass through the intestine but do not linger—due to a lack of the integrin CD103—fail to induce disease.

GVHD is a serious complication of bone marrow transplantation in which donor-derived T cells infiltrate and attack host epithelial tissues such as skin and intestine. Intestinal injury results from attack on host epithelial cells by donor CD8⁺ effector T cells. Previous studies by this group showed that CD8⁺ T cell–mediated rejection of pancreatic islet allografts required T cell expression of the integrin CD103 whose ligand, E-selectin, is preferentially expressed on epithelial cells.

El-Asady and colleagues now show that...