Binding of Escherichia coli adhesin AfaE to CD55 triggers cell-surface expression of the MHC class I-related molecule MICA.

ABSTRACT: MICA are distant homologs of MHC class I molecules expressed in the normal intestinal epithelium. They are ligands of the NKG2D activating receptor expressed on most gammadelta T cells, CD8+ alphabeta T cells, and natural killer cells and therefore play a critical role in innate immune responses. We investigated MICA cell-surface expression on infection of epithelial cell lines by enteric bacteria and show here that MICA expression can be markedly increased by bacteria of the diffusely adherent Escherichia coli diarrheagenic group. This effect is mediated by the specific interaction between bacterial adhesin AfaE and its cellular receptor, CD55, or decay-accelerating factor. It is extremely rapid after AfaE binding, consistent with a stress-induced signal. MICA induction on epithelial cell

SUBMITTER: Tieng V 

PROVIDER: S-EPMC122458 | biostudies-literature | 2002 Mar

REPOSITORIES: biostudies-literature