The dense low-density lipoprotein (LDL) subfractions are more potent than buoyant LDL for binding and neutralization of lipopolysaccharide

Abstract

Lipoproteins are able to bind the lipopolysaccharide (LPS) component of Gram-negative bacteria, leading to formation of lipoprotein-LPS complexes and inhibition of endotoxin-stimulated cytokines. The differential capacity of the low-density lipoprotein (LDL) and high-density lipoprotein (HDL) subfractions to bind and neutralize LPS has been studied in 11 healthy volunteers. The dense LDL2 and LDL3 subfractions were 20-25% more potent for the inhibition of endotoxin-induced production of tumor necrosis factor (TNF) than the buoyant LDL1 subfraction (P < 0.01). This may have important consequences for the LPS-responsiveness of patients with different LDL subfraction phenotypes, and for the formation of atherogenic LDL-LPS complexes in vivo. No differences in the capacity to neutralize LPS has been detected between the various HDL subfractions.