Abstract
The effects of Fusobacterium nucleatum lipopolysaccharide (LPS) and Escherichia coli LPS on DNA synthesis, protein synthesis, alkaline phosphatase activity, acid phosphatase activity, and morphological changes in human epithelial HeLa cells in the absence of fetal bovine serum were studied. F. nucleatum LPS inhibited ^3H-thymidine incorporation in cells up to 1 μg/ml, but inhibition by E. coli LPS was caused by adding over 50 μg/ml. Inhibition of protein synthesis by F. nucleatum LPS and E. coli LPS was observed at concentrations of 0.01μg/ml and 10μg/ml, respectively. We also examined whether LPS affects the alkaline phosphatase in HeLa cells. F. nucleatum LPS at concentrations of 0.01 to 25μg/ml inhibited alkaline phosphatase activity in a dose dependent fashion, but E. coli LPS did not inhibit it at a concentration of 25μg/ml. Acid phophatase activity also was inhibited at a concentration of 10 μg/ml of F. nucleatum LPS, but not by E. coli LPS at the same concentration. The morphological changes in HeLa cells caused by F. nucleatum LPS treatment were greater than those caused by E. coli LPS. The results suggest that the cytotoxic effect of F. nucleatum LPS may be greater than that of E. coli LPS.
