Fig. 1: CD1c-TCR ligand trapping.
From: Sideways lipid presentation by the antigen-presenting molecule CD1c
a Size-exclusion profiles of CD1c plus TCR show that complexes comigrating with CD1c monomers (fractions 37-39), and a biphasic curve with weakly (fractions 33-35) and strongly (fractions 26-31) excluded complexes. b, c Targeted MS analysis of lipids strongly and weakly excluded identified small monoacyl ligands, and a dual chain weak TCR ligator, sphingomyelin, respectively. d–f Whereas the single chain headless lipid, monoacylglycerol (MAG), binds inside CD1c to allow a tight CD1c-TCR interface that surrounds the F′ antigen exit portal (olive), lipidomics analysis of weak ligators of CD1c-TCR identified 26 dual chain lipids with large headgroups (red), whose mechanism of CD1c binding was unknown. g Unsupervised clustering analysis of ligands shows strongly excluded fractions are headless single chain lipids, weakly excluded fractions are dual chain lipids with large headgroups. Elutional lipidomics was performed twice with similar results.
