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LPS induction of gene expression in human monocytes
1Departments of Immunology, C-204, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Cellular Signalling
|March 21, 2001
Summary
Lipopolysaccharide (LPS) from Gram-negative bacteria triggers innate immune cells like monocytes. This interaction activates key inflammatory signaling pathways, leading to the production of inflammatory mediators.
Area of Science:
- Immunology
- Microbiology
Background:
- Lipopolysaccharide (LPS), an endotoxin, is a major component of Gram-negative bacterial outer membranes.
- Monocytes and macrophages are key cells of the innate immune system that recognize LPS.
Purpose of the Study:
- To elucidate the molecular mechanisms by which human monocytes recognize LPS.
- To identify the intracellular signaling pathways activated by LPS in human monocytes.
Main Methods:
- LPS binding to LPS-binding protein (LBP) and CD14.
- LPS transfer to Toll-like receptor 4 (TLR4) and MD2 complex.
- Analysis of intracellular signaling pathways including IKK-NF-kappaB and MAPK pathways (ERK, JNK, p38).
Main Results:
- Human monocytes are highly sensitive to LPS, inducing inflammatory cytokine expression.
- LPS recognition involves LBP, CD14, TLR4, and MD2.
- LPS activates IKK-NF-kappaB and MAPK signaling cascades.
Conclusions:
- LPS stimulation of human monocytes leads to the activation of transcription factors NF-kappaB and AP-1.
- Activated transcription factors coordinate the induction of genes encoding inflammatory mediators, contributing to the inflammatory response.