A structural basis for selection and cross-species reactivity of the semi-invariant NKT cell receptor in CD1d/glycolipid recognition.

ABSTRACT: Little is known regarding the basis for selection of the semi-invariant alphabeta T cell receptor (TCR) expressed by natural killer T (NKT) cells or how this mediates recognition of CD1d-glycolipid complexes. We have determined the structures of two human NKT TCRs that differ in their CDR3beta composition and length. Both TCRs contain a conserved, positively charged pocket at the ligand interface that is lined by residues from the invariant TCR alpha- and semi-invariant beta-chains. The cavity is centrally located and ideally suited to interact with the exposed glycosyl head group of glycolipid antigens. Sequences common to mouse and human invariant NKT TCRs reveal a contiguous conserved "hot spot" that provides a basis for the reactivity of NKT cells across species. Structural and functio

SUBMITTER: Kjer-Nielsen L 

PROVIDER: S-EPMC2118261 | biostudies-literature | 2006 Mar

REPOSITORIES: biostudies-literature