Table 1.
Synthetic, microbial, and self NKT cell agonists—structures and properties.
| Lipid (class) | Chain Lengtha | Structure | Agonistb | Reference |
|---|---|---|---|---|
| αGalCer (GSL) | C18; C24:1 |  |
IFN-γ, IL-4 self | (19) |
| Agel 9b (GSL) | C17 (C16-Me); phyto C24 |  |
Anti-tumor; Agelas mauritianus | (20, 21) |
| KRN7000 αGalCer (GSL) | C18-phyto; C26 |  |
Very strong; robust IFN-γ IL-4 and other cytokines; synthetic analog of Agel 9b | (22) |
| αCGal-Cer (GSL) | C18-phyto; C26 |  |
Weak (mo)-to-none (hu); IFN-γ; synthetic | (23) |
| OCH (GSL) | C9-phyto; C24 |  |
Weak (mo)-to-none (hu); IL-4 (low-to-no IFN-γ); synthetic | (24) |
| C20-diene (GSL) | C18-phyto; C20:2 |  |
Strong; IL-4 (low-to-no IFN-γ); synthetic | (25) |
| αGalCer (GSL) | C17-C3OH; C17 |  |
Stimulatory and inhibitory Bacteroides fragilis | (26, 27) |
| αGalU Cer (GSL) | C18-phyto; C14 |  |
Weak; Sphingomonas spp. | (28–30) |
| Asp B (GSL) | C20:2-C9 Me; C16-C2 OH |  |
Weak; Aspergillus fumigatus | (31) |
| αGlc-6-acyl-Chol | C14 |  |
Strong; binds a small NKT cell subset (mo); Helicobacter pylori | (32) |
| βGalCer (GSL) | C18; C24:1 |  |
Weak; self | (33, 34) |
| iGb3 (GSL) | C18; C24 |  |
Weak (mo)-to-none (hu); self | (35) |
| αGal-DAG (GGL) | sn1-C18:1; sn2-C16 |  |
Weak (mo)-to-none (hu); Borrelia burgdorferi | (36) |
| αGlc-DAG (GGL) | sn1-C18:1; sn2-C16 |  |
Weak; Streptococcus pneumoniae | (37) |
| PtdIno (GPL) | sn1-C18:1; sn2-C18:1 |  |
Week (mo)-to-no (hu); self | (38, 39) |
| Plasma-logen (GPL) | sn1-C16 vinyl-ether; sn2-lyso |  |
Positive selection (mo); self | (40) |
| Lyso-PtdCho (GPL) | sn1-C16; sn2-lyso |  |
Weak (hu)-to-none (mo); GM-CSF (no IL-4, IFN-γ); self | (41) |
This table is adapted from Ref. (8, 42).
Agel, agelasphin; Asp B, asparamide B; Chol, cholesterol; DAG, diacylglycerol; GalCer, galactosylceramide; GalUCer, galacturonosylceramide; GlcCer, glucosylceramide; PtdCho, phosphatidylcholine; PtdIno, phosphatidylinositol; sn, stereo nomenclature for glycerolipids; GGL, glycoglycerolipid; GPL, glycerophospholipid; GSL, glycosphingolipid; mo, mouse; hu, human.
aSphingosine/phytosphingosine chain length indicated first and N-acyl chain length second.
bAgonist strength based on Ref. (43).