Table 1.
Gram-negative bacteria that express divergent lipid A structures.
| Bacterial strain | Acylation/phosphorylation | Toll-like receptor 4 activation | Outcomes | Reference |
|---|---|---|---|---|
| Helicobacter pylori | Mono-phosphorylated, tetra-acylated | Weak agonist | Bacterial survival | (119, 127) |
| Pseudomonas aeruginosa | Hepta-acylated | Strong agonist | Severe cystic fibrosis (CF), neutrophil survival | (120) |
| Penta-acylated | Weak agonist | Decreased IL-8, CF | ||
| Bacteroides thetaiotaomicron | Under-phosphorylated, penta-acylated | Weak agonist | Bacterial survival | (121, 128) |
| Porphyromonas gingivalis | Di-phosphorylated, penta-acylated | Agonist | Modest inflammation, decreased atherosclerosis | (108, 122) |
| Mono-phosphorylated, tetra-acetylated | Antagonist | Systemic inflammation, increased atherosclerosis | ||
| S. flexneri | Tri- or tetra-acylated | Weak agonist | Low cytokine production, inflammasome inhibition | (123) |
| Neisseria meningitidis | Penta-acylated | Non-activating | Low NFkB activation | (124) |
| Yersinia pestis | Hexa-acylated | Strong agonist | Bacterial clearance, no systemic disease | (125, 129, 130) |
| Tetra-acylated (37°C) | Weak agonist | Systemic disease | ||
| Francisella tularensis | Mono-phosphorylated, tetra-acetylated | Weak agonist | Decreased TNFα, bacterial survival | (126, 131, 132) |