TLR4 and infection: Lipopolysaccharide (LPS) sensingby toll-like receptor 4 (TLR4) is crucial in early responses to infection,where an uncontrolled LPS response gives rise to excessive localizedinflammation, such as that found in infected wounds, but also in severesystemic responses to infection.2,3 LPS and lipoteichoicacid (LTA) are recognized as pathogen-associated molecular patterns(PAMPs) by pattern recognition receptors such as toll-like receptors(TLRs).4 These receptors are expressedon innate immune cells, mainly by mononuclear phagocytes (monocytesand macrophages).