Figure 3.

Indirect effect of lactoferrin by means of host modulation. (A) Lactoferrin can interfere with the ability of lipopolysaccharide-binding protein (LBP) found in serum and emanating from the liver to bind to soluble lipopolysaccharide (LPS). Lactoferrin can also interfere with the transfer of LPS to soluble CD14. (B) Lactoferrin can also interfere with LPS transfer from LBP to membrane bound mCD14. CD14 receptors are found on the surface of monocytes, polymorphonuclear neutrophils, dendritic cells. (C) Transfer of LBP bound LPS from CD14 to myeloid differentiating protein 2 (MD-2) occurs. LPS transfer to MD-2 allows for association of LPS with Toll-like 4 receptors for dimerization. (D) This dimerization of Toll-like receptors causes membrane perturbation and cell signaling resulting in cytokine production. Lf, lactoferrin; TLR4, Toll-like receptor 4.