6D64

Crystal Structure of Human CD1b in Complex with POPC

Summary for 6D64

• Entry DOI: 10.2210/pdb6d64/pdb
• Descriptor: T-cell surface glycoprotein CD1b, SODIUM ION, IODIDE ION, ... (12 entities in total)
• Functional Keywords: bc8b, cd1, cd1b, pc, popc, phosphatidylcholine, immune system
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 2
• Total formula weight: 50428.12

Authors

Shahine, A.E.,Rossjohn, J. (deposition date: 2018-04-20, release date: 2019-01-16, Last modification date: 2024-11-06)

Primary citation

Shahine, A.,Reinink, P.,Reijneveld, J.F.,Gras, S.,Holzheimer, M.,Cheng, T.Y.,Minnaard, A.J.,Altman, J.D.,Lenz, S.,Prandi, J.,Kubler-Kielb, J.,Moody, D.B.,Rossjohn, J.,Van Rhijn, I.
A T-cell receptor escape channel allows broad T-cell response to CD1b and membrane phospholipids.
Nat Commun, 10:56-56, 2019

PubMed Abstract: CD1 proteins are expressed on dendritic cells, where they display lipid antigens to T-cell receptors (TCRs). Here we describe T-cell autoreactivity towards ubiquitous human membrane phospholipids presented by CD1b. These T-cells discriminate between two major types of lipids, sphingolipids and phospholipids, but were broadly cross-reactive towards diverse phospholipids including phosphatidylcholine, phosphatidylinositol and phosphatidylethanolamine. The crystal structure of a representative TCR bound to CD1b-phosphatidylcholine provides a molecular mechanism for this promiscuous recognition. We observe a lateral escape channel in the TCR, which shunted phospholipid head groups sideways along the CD1b-TCR interface, without contacting the TCR. Instead the TCR recognition site involved the neck region phosphate that is common to all major self-phospholipids but absent in sphingolipids. Whereas prior studies have focused on foreign lipids or rare self-lipids, we define a new molecular mechanism of promiscuous recognition of common self-phospholipids including those that are known targets in human autoimmune disease.

PubMed: 30610190
DOI: 10.1038/s41467-018-07898-0

Experimental method

X-RAY DIFFRACTION (1.7 Å)