4X6D

CD1a ternary complex with endogenous lipids and BK6 TCR

Summary for 4X6D

• Entry DOI: 10.2210/pdb4x6d/pdb
• Related: 4X6B 4X6C 4X6E 4X6F
• Descriptor: T-cell surface glycoprotein CD1a, Beta-2-microglobulin, TCR alpha, ... (8 entities in total)
• Functional Keywords: cd1a, tcr, immune complex, lipid antigen, immune system
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 8
• Total formula weight: 189501.71

Authors

Birkinshaw, R.W.,Rossjohn, J. (deposition date: 2014-12-08, release date: 2015-01-28, Last modification date: 2024-10-23)

Primary citation

Birkinshaw, R.W.,Pellicci, D.G.,Cheng, T.Y.,Keller, A.N.,Sandoval-Romero, M.,Gras, S.,de Jong, A.,Uldrich, A.P.,Moody, D.B.,Godfrey, D.I.,Rossjohn, J.
alpha beta T cell antigen receptor recognition of CD1a presenting self lipid ligands.
Nat.Immunol., 16:258-266, 2015

PubMed Abstract: A central paradigm in αβ T cell-mediated immunity is the simultaneous co-recognition of antigens and antigen-presenting molecules by the αβ T cell antigen receptor (TCR). CD1a presents a broad repertoire of lipid-based antigens. We found that a prototypical autoreactive TCR bound CD1a when it was presenting a series of permissive endogenous ligands, while other lipid ligands were nonpermissive to TCR binding. The structures of two TCR-CD1a-lipid complexes showed that the TCR docked over the A' roof of CD1a in a manner that precluded direct contact with permissive ligands. Nonpermissive ligands indirectly inhibited TCR binding by disrupting the TCR-CD1a contact zone. The exclusive recognition of CD1a by the TCR represents a previously unknown mechanism whereby αβ T cells indirectly sense self antigens that are bound to an antigen-presenting molecule.

PubMed: 25642819
DOI: 10.1038/ni.3098

Experimental method

X-RAY DIFFRACTION (2.98 Å)