Related Experiment Video

Updated: Jun 21, 2026

Isolation Protocol of Mouse Monocyte-derived Dendritic Cells and Their Subsequent In Vitro Activation with Tumor Immune Complexes
11:48

Isolation Protocol of Mouse Monocyte-derived Dendritic Cells and Their Subsequent In Vitro Activation with Tumor Immune Complexes

Published on: May 31, 2018

Lipopolysaccharide-driven Th2 cytokine production in macrophages is regulated by both MyD88 and TRAM

Sumanta Mukherjee1, Ling-Yu Chen, Thomas J Papadimos

  • 1Department of Medicine, University of Toledo Medical Center, Toledo, Ohio 43614, USA.

The Journal of Biological Chemistry
|July 30, 2009
PubMed

Insights

Lipopolysaccharide (LPS) from Gram-negative bacteria stimulates macrophages to produce both Th1 and Th2 cytokines. LPS-induced IL-4 production requires both MyD88 and TRAM signaling pathways, unlike TNFalpha.

Area of Science:

  • Immunology
  • Cellular Biology
  • Molecular Signaling

Background:

  • Gram-negative bacterial lipopolysaccharide (LPS) is a potent activator of macrophages via Toll-like receptor 4 (TLR4).
  • LPS primarily induces pro-inflammatory Th1-type cytokines, but its role in Th2-type cytokine production by macrophages is less understood.
  • Investigating the intracellular mechanisms of LPS-induced Th2 cytokine expression is crucial for understanding macrophage polarization.

Purpose of the Study:

  • To elucidate the molecular mechanisms underlying lipopolysaccharide (LPS)-induced type 2 cytokine gene expression in macrophages.
  • To investigate the roles of MyD88 and TRAM signaling pathways in LPS-mediated production of IL-4 and TNFalpha.

Main Methods:

  • Macrophages were stimulated with LPS, and the expression of IL-4 and IL-5 genes was analyzed.
  • Small interfering RNA (siRNA) was used to silence myeloid differentiation factor 88 (MyD88) and TRIF-related adaptor molecule (TRAM).
  • Protein levels of TNFalpha and IL-4 were measured following LPS stimulation and gene silencing.

Main Results:

  • LPS stimulation induced both Th1 (e.g., TNFalpha) and Th2 (e.g., IL-4) cytokine production in macrophages.
  • TNFalpha was rapidly released within 4 hours, while IL-4 release was observed after 48 hours of LPS stimulation.
  • Silencing of MyD88 and TRAM abolished LPS-induced IL-4 production, whereas TNFalpha induction was MyD88-dependent but TRAM-independent.

Conclusions:

  • LPS, acting through TLR4, can induce both type 1 and type 2 cytokine production in macrophages.
  • LPS-induced IL-4 gene expression requires the coordinated action of both MyD88 and TRAM signaling pathways.
  • These findings reveal a novel role for LPS and distinct signaling pathways in regulating IL-4 production.

More Related Videos

Legionella pneumophila Outer Membrane Vesicles: Isolation and Analysis of Their Pro-inflammatory Potential on Macrophages08:34

Legionella pneumophila Outer Membrane Vesicles: Isolation and Analysis of Their Pro-inflammatory Potential on Macrophages

Published on: February 22, 2017

A Macrophage Reporter Cell Assay to Examine Toll-Like Receptor-Mediated NF-kB/AP-1 Signaling on Adsorbed Protein Layers on Polymeric Surfaces07:55

A Macrophage Reporter Cell Assay to Examine Toll-Like Receptor-Mediated NF-kB/AP-1 Signaling on Adsorbed Protein Layers on Polymeric Surfaces

Published on: January 7, 2020

Related Concept Videos

Formation of Lipopolysaccharides01:19

Formation of Lipopolysaccharides

Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin, triggering...
T Cell Types and Functions01:24

T Cell Types and Functions

When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...