TLR4 signaling of LPS chemotypes in HEK Blue hTLR4 reporter cells.

The discovery of Toll-like receptors (TLRs) represented a significant breakthrough that paved the way for the study of host-pathogen interactions in innate immunity. However, there are still major gaps in understanding TLR function, especially the early dynamics of downstream TLR pathways remains less clear. We characterize a label-free optical biosensor-based assay as a powerful method to detect TLR activation in a native and label-free environment and to delineate the dynamics of TLR pathway activation. To gain a deeper insight into the biological processes underlying the ligand-specific signal traces of different LPS chemotypes in various cell types, RNA-seq analysis of transcriptional changes in HEK Blue hTLR4 reporter cells was performed. After 3 hours of stimulation with LPS E. coli or LPS S. minnesota, HEK Blue hTLR4 reporter cells showed significant changes in RNA expression compared to the unstimulated control. HEK Blue hTLR4 reporter cells were stimulated with LPS E. coli or LPS S. minnesota for 3 hours. Unstimulated cells served as control. Gene expression profiling analysis was performed using data obtained from RNA-seq of two independent experiments.