Related Experiment Video
Updated: Mar 15, 2026
Activation and Measurement of NLRP3 Inflammasome Activity Using IL-1β in Human Monocyte-derived Dendritic Cells
Published on: May 22, 2014
Activation of nucleotide-binding domain-like receptor containing protein 3 inflammasome in dendritic cells and
Ayumi Saeki1, Toshihiko Suzuki2,3, Akira Hasebe1
1Division of Oral Molecular Microbiology, Department of Oral Pathobiological Science, Hokkaido University Graduate School of Dental Medicine, Sapporo, 060-8586, Japan.
Abstract:
Streptococcus sanguinis is frequently isolated from the blood of patients with infective endocarditis and contributes to the pathology of this disease through induction of interleukin (IL)-1β responsible for the development of the disease. However, the mechanism of IL-1β induction remains unknown. In this study, S. sanguinis activated a murine dendritic cell (DC) to induce IL-1β and this activity was attenuated by silencing the mRNAs of nucleotide-binding domain-like receptor containing protein 3 (NLRP3) and caspase-1. S. sanguinis induced IL-1β production in murine bone marrow-derived macrophage, but this activity was significantly reduced in bone marrow-derived macrophages from NLRP3-, apoptosis-associated speck-like protein containing a caspase-recruitment domain-, and caspase-1-deficient mice. DC phagocytosed S. sanguinis cells, followed by the release of adenosine triphosphate (ATP). The ATP-degradating enzyme attenuated the release of ATP and IL-1β. The inhibitors for ATP receptor reduced IL-1β release in DC. These results strongly suggest that S. sanguinis has the activity to induce IL-1β through the NLRP3 inflammasome in macrophage and DC and interaction of purinergic receptors with ATP released is involved in expression of the activity.
Insights
Streptococcus sanguinis induces interleukin-1β via the NLRP3 inflammasome in immune cells. This process involves adenosine triphosphate (ATP) and purinergic receptors, contributing to infective endocarditis pathology.
Area of Science:
- Immunology
- Microbiology
- Infectious Diseases
Background:
- Streptococcus sanguinis is a key pathogen in infective endocarditis.
- The mechanism by which S. sanguinis induces IL-1β, a critical inflammatory mediator in disease development, was previously unknown.
Purpose of the Study:
- To elucidate the mechanism of IL-1β induction by S. sanguinis.
- To investigate the role of the NLRP3 inflammasome and purinergic signaling in S. sanguinis-induced IL-1β production.
Main Methods:
- Murine dendritic cells (DCs) and bone marrow-derived macrophages (BMDMs) were used to study IL-1β induction.
- Gene silencing of NLRP3 and caspase-1, and use of knockout mice deficient in NLRP3, ASC, or caspase-1 were employed.
- The role of adenosine triphosphate (ATP) and purinergic receptors was assessed using ATP-degrading enzymes and receptor inhibitors.
Main Results:
- S. sanguinis activated DCs and macrophages to induce IL-1β production.
- IL-1β induction was significantly attenuated by silencing NLRP3 and caspase-1, and in knockout cells.
- Phagocytosis of S. sanguinis by DCs led to ATP release, which was linked to IL-1β production via purinergic receptors.
Conclusions:
- S. sanguinis induces IL-1β through the NLRP3 inflammasome pathway in macrophages and DCs.
- Purinergic signaling, involving released ATP and its receptors, is crucial for this IL-1β induction.
- Understanding this mechanism provides insights into the pathogenesis of infective endocarditis.
More Related Videos
06:52Detection of Inflammasome Activation and Pyroptotic Cell Death in Murine Bone Marrow-derived Macrophages
Published on: May 21, 2018
11:48Isolation Protocol of Mouse Monocyte-derived Dendritic Cells and Their Subsequent In Vitro Activation with Tumor Immune Complexes
Published on: May 31, 2018
Related Concept Videos
01:38Inflammation
02:26NF-κB-dependent Signaling Pathway
NF-κB-dependent Signaling Mechanism
The...