Related Experiment Video

Updated: Aug 12, 2026

Activation and Measurement of NLRP3 Inflammasome Activity Using IL-1β in Human Monocyte-derived Dendritic Cells
09:04

Activation and Measurement of NLRP3 Inflammasome Activity Using IL-1β in Human Monocyte-derived Dendritic Cells

Published on: May 22, 2014

Leptospiral lipopolysaccharide activates cells through a TLR2-dependent mechanism

C Werts1, R I Tapping, J C Mathison

  • 1Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA.

Nature Immunology
|March 29, 2001
PubMed

Insights

Leptospira interrogans outer membrane components, lipopolysaccharide (LPS) and lipoproteins, activate macrophages via Toll-like receptor 2 (TLR2). LPS is the primary signaling molecule, not TLR4, in this innate immune response.

Area of Science:

  • Microbiology
  • Immunology
  • Infectious Diseases

Background:

  • Leptospira interrogans are zoonotic pathogens causing increased illness and death in tropical urban areas.
  • These spirochetes possess unique outer membrane components: lipopolysaccharide (LPS) and lipoproteins.

Purpose of the Study:

  • To investigate how L. interrogans outer membrane components activate macrophages.
  • To determine the roles of Toll-like receptor 2 (TLR2) and TLR4 in the cellular response to L. interrogans.

Main Methods:

  • Macrophage activation assays using L. interrogans outer membrane constituents.
  • Analysis of cellular signaling pathways involving CD14, TLR2, and TLR4.

Main Results:

  • Both LPS and lipoproteins from L. interrogans activate macrophages through CD14 and TLR2.
  • Toll-like receptor 4 (TLR4) is not involved in the cellular response to L. interrogans.
  • For intact L. interrogans, LPS is the predominant signaling component activating macrophages via TLR2.

Conclusions:

  • Leptospiral LPS and lipoproteins are key activators of the innate immune response through TLR2.
  • This study reveals a novel ligand specificity for TLR2 in the context of leptospirosis.
  • Findings provide a foundation for understanding leptospirosis pathogenesis and immune evasion.

More Related Videos

Screening Bioactive Nanoparticles in Phagocytic Immune Cells for Inhibitors of Toll-like Receptor Signaling09:51

Screening Bioactive Nanoparticles in Phagocytic Immune Cells for Inhibitors of Toll-like Receptor Signaling

Published on: July 26, 2017

Injections of Lipopolysaccharide into Mice to Mimic Entrance of Microbial-derived Products After Intestinal Barrier Breach08:24

Injections of Lipopolysaccharide into Mice to Mimic Entrance of Microbial-derived Products After Intestinal Barrier Breach

Published on: May 2, 2018

Related Concept Videos

T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...
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...
B Cell Activation and Differentiation01:24

B Cell Activation and Differentiation

The adaptive immune response, a sophisticated defense mechanism, relies on the activation and differentiation of B lymphocytes, or B cells. These processes enable our bodies to mount a tailored response against specific pathogens such as bacteria, free virus particles, toxins, and parasites.
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
Defense Against Bacterial Pathogens01:31

Defense Against Bacterial Pathogens

The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
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...
Bacterial Phylum Spirochaetes01:30

Bacterial Phylum Spirochaetes

Spirochetes, unique bacteria in the phylum Spirochaetes, are gram-negative, motile, tightly coiled, slender, and flexible. They inhabit aquatic sediments and animals, with some causing diseases like syphilis. Spirochetes are classified into eight genera based on habitat, pathogenicity, phylogeny, and characteristics.Their distinctive motility arises from endoflagella, located within the cell’s periplasm. These endoflagella anchor at the cell poles and extend along the cell length, encased by a...