Macrophage stimulation with Murabutide, an HIV‐suppressive muramyl peptide derivative, selectively activates extracellular signal‐regulated kinases 1 and 2, C / EBPβ and STAT1: role of CD14 and Toll‐like receptors 2 and 4

These findings present major differences in the early cell activation process between LPS and muramyl peptides, and strongly argue for the implication of co‐receptors other than TLR2 and TLR4 in mediating the signaling events induced by defined subunits of bacterial peptidoglycans.