LPS and its lipid A moiety stimulate cells of the innate immune system by the Toll-like receptor 4 (TLR4), a member of the Toll-like receptor protein family, which recognizes common pathogen-associated molecular patterns (PAMPs).
Additionally, it was demonstrated that the mechanisms by which LPS from E. coli and P. gingivalis modulate cluster of differentiation 14 (CD14), toll-like receptor 2 (TLR2), and toll-like receptor 4 (TLR4) surface expression, primary and secondary cytokine responses are different.
Porphyromonas gingivalis is a Gram-negative bacterium that is known to be involved in adult periodontitis. Periodontitis is a chronic inflammatory disease characterized by the recession of the supportive tissue surrounding teeth. Studies have shown that the LPS from P. gingivalis plays an important role in this disease.
A recent study demonstrated that LPS from P. gingivalis stimulates insulin secretion by the pancreatic β cell line, MIN6. In the presence of 5 mM glucose and 50-500 ng/mL LPS from P. gingivalis, a significant induction of insulin secretion was observed.