The cell wall of Gram-positive bacteria conain large amounts of lipoteichoic acid (LTA). We have found that LTA is endowed with immunostimulatory properties, the expression of which depends on its bacterial source.
It has been demonstrated LTA shows positive response in Limulus amoebocyte assay (LAL), mimicking thus lipopolysaccharide (LPS) of Gram-negative bacteria. Similar to LPS, LTA binds to the antibiotics polymyxinB.