Figure 4. LPS determination.

Shed LPS was determined in the culture supernatant from both directly and indirectly infected THP-1 cells with P12 and 26695 strains at the indicated time intervals. LPS was detected by Limulus amebocyte lysate assay (LAL) kit (Pierce Themo Scientific) as per the manufacture’s instruction and E. coli LPS served as a positive control. Data represent the mean and SD values of three replicates. UI indicates uninduced cells and * indicates significant difference where P < 0.05.