The aim of the studies was to analyze the influence of Gram-negative and -positive wound infection relevant bacteria and their cell wall components LPS and LTA on cellular processes (e.g. proliferation, osteogenic and adipogenic differentiation, NF-kappaB signaling, migration and chemotaxis) of adMCS. We could show that, the LPS-induced increase in proliferation and osteogenic differentiation of adMSC could be abolished by competitive inhibition of TLR4. The data strengthen the evidence for a role of TLR4 in the regulation of proliferation and differentiation of adMSC.