Summary
Cytosolic complexes that activate caspase-1 to release IL-1 beta and trigger pyroptosis.
In depth
NLRP3 senses danger signals such as crystals and potassium efflux, activating caspase-1, which cleaves pro-IL-1β and gasdermin D to cause pyroptosis. Gain-of-function mutations cause periodic fever syndromes.
Inflammasome assembly uses ASC adaptor proteins forming specks. Overactivation causes autoinflammatory diseases. Inhibitors (such as for NLRP3) are being tested for gout and heart disease.
Key idea: they sense danger and convert it into inflammatory signalling.
Inflammasomes are protein complexes that assemble in the cytoplasm, with a sensor (NLRP3, NLRC4, AIM2 for DNA, pyrin), the adaptor ASC and caspase-1. Active caspase-1 cleaves pro-IL-1 beta and pro-IL-18, and gasdermin D forms pores that cause pyroptosis, an inflammatory cell death. NLRP3 responds to uric acid crystals, cholesterol crystals, asbestos, and ATP.
Overactivation leads to disease: gout, atherosclerosis, type 2 diabetes and Alzheimer disease have all been linked to NLRP3. Gain-of-function mutations cause cryopyrin-associated periodic syndromes, treated with IL-1 blockers (anakinra, canakinumab). Pathogens such as Yersinia inhibit inflammasomes.
Example: in gout, urate crystals in joints trigger NLRP3 and IL-1 beta, producing intense pain and swelling.
Frequently asked questions
What is Inflammasomes?
Cytosolic complexes that activate caspase-1 to release IL-1 beta and trigger pyroptosis.
Which area of biology covers Inflammasomes, and how advanced is it?
Inflammasomes is one of the 52 topics in Immunology & Disease. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Inflammation, Cytokines, Complement System.
Can you give an example of Inflammasomes?
Uric acid crystals activate NLRP3 in gout.
What should I learn before Inflammasomes?
Work through the Beginner topics in Immunology & Disease first, such as Immune System, Viruses, Innate Immunity, then return to Inflammasomes. Advanced topics assume the Intermediate vocabulary.
What topics are related to Inflammasomes?
The closest topics to Inflammasomes are Inflammation, Cytokines, Complement System, Immunosenescence. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Inflammasomes?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Inflammasomes. To practise the whole of Immunology & Disease, use the Immunology & Disease quiz.
How is Inflammasomes different from Inflammation?
Inflammasomes: Cytosolic complexes that activate caspase-1 to release IL-1 beta and trigger pyroptosis. Inflammation: A response with redness, heat, swelling and pain that brings immune cells to damaged tissue. Read both side by side and note what each one explains.
How should I study Inflammasomes step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Inflammation and explain the difference aloud. Finally, take the Immunology & Disease quiz and come back to this page for any question you miss.