LPS-PG is a lipopolysaccharide from Porphyromonas gingivalis (P. gingivalis). It functions as a crucial virulence factor in the pathogenesis of periodontal disease by activating immune cells through Toll-like receptor 2 (TLR2), rather than the Escherichia coli (E. coli) receptor, Toll-like receptor 4 (TLR4). A lipoprotein from LPS-PG has been identified as the primary component responsible for TLR2-mediated cell activation.