Related Experiment Video

Updated: Aug 8, 2026

Development and Functional Characterization of Murine Tolerogenic Dendritic Cells
09:51

Development and Functional Characterization of Murine Tolerogenic Dendritic Cells

Published on: May 18, 2018

Colitogenic and non-colitogenic commensal bacteria differentially trigger DC maturation and Th cell polarization: an

Julia S Frick1, Naima Zahir, Martina Müller

  • 1Institute of Medical Microbiology and Hygiene, University of Tübingen, Germany. julia-stefanie.frick@med.uni-tuebingen.de

European Journal of Immunology
|May 19, 2006
PubMed

Insights

Commensal bacteria, Bacteroides vulgatus, prevent colitis by inducing semi-mature dendritic cells (DCs) via IL-6. These semi-mature DCs are unresponsive to pro-inflammatory E. coli, protecting against colitis.

Area of Science:

  • Immunology
  • Microbiology
  • Gastroenterology

Background:

  • Commensal bacteria play a crucial role in host immune homeostasis.
  • Dendritic cells (DCs) are key antigen-presenting cells that bridge innate and adaptive immunity.
  • Dysbiosis and inflammation contribute to inflammatory bowel diseases like colitis.

Purpose of the Study:

  • To investigate how commensal bacteria modulate dendritic cell (DC) activation and maturation.
  • To determine the impact of DC modulation on CD4(+) T cell priming.
  • To elucidate the mechanism by which Bacteroides vulgatus prevents E. coli-induced colitis.

Main Methods:

  • Utilized gnotobiotic IL-2-deficient mice challenged with Escherichia coli and Bacteroides vulgatus.
  • Stimulated bone marrow-derived DCs with E. coli and B. vulgatus.
  • Assessed DC activation markers, cytokine secretion (TNF-alpha, IL-12, IL-6), and T cell priming (Th1 polarization).
  • Investigated the role of IL-6 in DC hyporesponsiveness using anti-IL-6 mAb and recombinant IL-6 (rIL-6).

Main Results:

  • E. coli stimulation induced DC maturation, pro-inflammatory cytokine secretion (TNF-alpha, IL-12, IL-6), and Th1 polarization.
  • B. vulgatus stimulation led to IL-6 secretion, driving DCs into a semi-mature state with low activation markers.
  • Semi-mature DCs induced by B. vulgatus were hyporesponsive to E. coli activation, except for IL-6 production.
  • IL-6 was identified as the key mediator of B. vulgatus-induced DC hyporesponsiveness.
  • High IL-6 mRNA expression correlated with the absence of colitis in B. vulgatus-colonized mice.

Conclusions:

  • Bacteroides vulgatus induces a semi-mature dendritic cell phenotype through IL-6 secretion.
  • This IL-6-mediated semi-maturation renders DCs hyporesponsive to pro-inflammatory stimuli like E. coli.
  • This mechanism likely contributes to the protective effect of B. vulgatus against E. coli-induced colitis in vivo.

More Related Videos

Generation of Immature, Mature and Tolerogenic Dendritic Cells with Differing Metabolic Phenotypes06:09

Generation of Immature, Mature and Tolerogenic Dendritic Cells with Differing Metabolic Phenotypes

Published on: June 22, 2016

Induction of Intestinal Inflammation by Adoptive Transfer of CBir1 TCR Transgenic CD4+ T Cells to Immunodeficient Mice07:34

Induction of Intestinal Inflammation by Adoptive Transfer of CBir1 TCR Transgenic CD4+ T Cells to Immunodeficient Mice

Published on: December 16, 2021

Related Concept Videos

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...
Inflammatory Bowel Disease III: Crohn's Disease01:25

Inflammatory Bowel Disease III: Crohn's Disease

Crohn’s disease is a chronic, relapsing form of inflammatory bowel disease characterized by segmental, transmural inflammation that can affect any part of the gastrointestinal tract. Its pathogenesis arises from a combination of genetic susceptibility, environmental exposures, epithelial barrier dysfunction, and immune dysregulation. Together, these factors lead to an exaggerated immune response against components of the gut microbiome.Genetic and Environmental InfluencesMultiple genetic...
Differentiation of Common Myeloid Progenitor Cells01:15

Differentiation of Common Myeloid Progenitor Cells

Common myeloid progenitors (CMPs) are oligopotent cells that can differentiate into granulocytes and macrophages. Granulocytes and macrophages are essential for protecting the body against bacterial, viral, or fungal infections. They migrate from the bone marrow into the circulating blood to reach specific tissue sites where they differentiate and help in immune surveillance. However, they survive only for a few days and must be continuously made available to the organism to maintain a robust...
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...
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...
Renewal of Intestinal Stem Cells01:23

Renewal of Intestinal Stem Cells

The intestinal epithelial lining rapidly renews every 4 to 5 days. The renewal is facilitated by intestinal stem cells (ISCs) located at the base of the crypt– a gland located at the bottom of each villus. ISCs divide asymmetrically to form new stem cells and progenitor daughter cells. The daughter cells are called transit-amplifying (TA) cells which move upwards along the crypt and either differentiate into absorptive cells– the enterocytes or secretory cells– including the goblet,...