Figure 1.

Bacterial lysate promotes inflammatory cytokine production and activates TLR2 and TLR4. (A) THP-1 cells (10⁶ cells/well) were stimulated with various doses of LPS (for comparison) or bacterial lysate, and TNF-α production (in ng/mL) was subsequently measured in the supernatants 24hs post stimulation. Panel represents fold-increase in cytokine production. (B, C, D) Human PBMC (10⁶ cells/well) were stimulated with different concentrations of bacterial lysate, and subsequently assayed for IL-6, IL-1β and TNF-α production 24 hs after stimulation. (E & F) Murine and human TLR activation by bacterial lysate in HEK293 cells expressing individual TLRs (see Materials and Methods). Ultrapure LPS from E. coli and peptidoglycan from E. coli K12 were used as positive controls for TLR4 and TLR2, respectively (data not shown). Two independent experiments were performed for each experimental paradigm; panels show one representative experiment of each pair.