CD14 Mediates Binding of High Doses of LPS but Is Dispensable for TNF-α Production
Figure 2
Silencing of TLR4 gene expression significantly downregulates production of TNF-α and RANTES in cells stimulated with sLPS or rLPS. RAW264 cells were transfected with TLR4-specific siRNA or scrambled siRNA and, after 50 h, stimulated with 10–1000 ng/mL sLPS (a, b) or 10–1000 ng/mL rLPS (c, d). Production of TNF-α (a, c) and RANTES (b, d) by the cells was estimated by ELISA tests. Data shown are mean ± SEM from three experiments each run in triplicate. *Significantly different from cells treated with scrambled siRNA and stimulated with a corresponding LPS concentration. (e) Immunoblotting analysis of TLR4 protein level versus actin level in cells transfected with TLR4-specific or scrambled (sc) siRNA. nt: not transfected cells. On the left, a molecular weight marker (prestained phosphorylase b, 101 kDa) is indicated. Data from two independent experiments are shown.
