GO:0140634 CARD8 inflammasome complex: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0140634 CARD8 inflammasome complex is a cellular component defined as an inflammasome complex that consists of CARD8 and CASP1.
• CARD8 acts as a sensor for danger signals and pathogen-derived activities, including HIV-1 protease and SFTSV non-structural protein, leading to CASP1 activation and pyroptosis.
• The CARD8 inflammasome is structurally distinct from NLRP1, with a unique CARD8-CASP1 assembly mechanism.
• CARD8 has anti-inflammatory and anti-apoptotic roles in addition to its inflammasome function.
• Dysregulation of CARD8 inflammasome is implicated in infectious diseases, inflammatory disorders, and cancer.
• CRISPR-based models (knockout, point mutation, knock-in, overexpression) are essential for dissecting CARD8 inflammasome biology and therapeutic targeting.
Description
The CARD8 inflammasome complex (GO:0140634) is a recently defined cellular component that consists of the sensor protein CARD8 and the effector caspase CASP1. It belongs to the growing family of inflammasome complexes that mediate innate immune responses to pathogens and danger signals. Unlike the well-studied NLRP3 inflammasome, CARD8 functions as a sensor for specific pathogen-derived activities, such as the HIV-1 protease, which cleaves CARD8 to trigger inflammasome assembly. This complex is critical for inducing pyroptosis, a lytic form of cell death that releases inflammatory cytokines and alerts the immune system. Researchers study the CARD8 inflammasome to understand host-pathogen interactions, inflammatory diseases, and potential therapeutic targets.
CARD8 inflammasome complex At A Glance
| GO ID | GO:0140634 |
|---|---|
| GO term | CARD8 inflammasome complex |
| Ontology | cellular_component |
| Synonym | None |
| Major function | Sensing pathogen-derived activities and danger signals to activate CASP1 and induce pyroptosis |
| Components | CARD8 and CASP1 |
| Assembly trigger | Proteolytic cleavage of CARD8 by pathogen proteases such as HIV-1 protease |
| Associated diseases | HIV-1 infection, inflammatory disorders, cancer |
What Is GO:0140634?
The CARD8 inflammasome complex is a multi-protein cellular component composed of CARD8 and CASP1, as defined by the Gene Ontology (GO:0140634). It is an inflammasome complex that assembles in response to specific danger signals, leading to CASP1 activation and downstream inflammatory signaling.
Why Is CARD8 inflammasome complex Important in Cell Biology?
The CARD8 inflammasome complex is important because it represents a distinct innate immune sensing mechanism that detects specific pathogen-encoded proteases, such as HIV-1 protease, and triggers pyroptosis to limit infection. Its unique structural assembly, differing from NLRP1, provides insights into inflammasome diversity and regulation. Dysregulation of CARD8 inflammasome activity is linked to inflammatory diseases and cancer, making it a potential therapeutic target.
• Mediates host defense against HIV-1 by detecting viral protease activity.
• Acts as a sensor for SFTSV non-structural protein, activating NLRP1 and CARD8 inflammasomes.
• Plays a role in pyroptosis and inflammatory cytokine release.
• Exhibits anti-inflammatory and anti-apoptotic activities in certain contexts.
• Structurally distinct from NLRP1 inflammasome, offering unique mechanistic insights.
• Implicated in cancer biology and potential immunotherapy targets.
• Provides a model for studying pathogen-driven inflammasome activation.
• Enables CRISPR-based functional genomics of inflammasome components.
Structure and Composition of CARD8 inflammasome complex
CARD8 sensor protein
In simple terms: CARD8 is the sensor that detects danger signals.
CARD8 is a member of the CARD-containing protein family and functions as the sensor component of the CARD8 inflammasome complex. It contains a caspase activation and recruitment domain (CARD) that mediates interactions with CASP1. CARD8 is activated by proteolytic cleavage, particularly by pathogen-derived proteases such as HIV-1 protease, which removes an inhibitory N-terminal fragment.
CASP1 effector protein
In simple terms: CASP1 is the enzyme that executes inflammatory cell death.
CASP1 (caspase-1) is the effector component of the CARD8 inflammasome complex. Upon recruitment by CARD8, CASP1 undergoes autoproteolytic activation and cleaves downstream substrates such as gasdermin D to induce pyroptosis and release IL-1beta and IL-18.
Assembly and activation
In simple terms: The complex assembles when CARD8 is cleaved, allowing CASP1 to activate.
Assembly of the CARD8 inflammasome complex is triggered by proteolytic cleavage of CARD8, which relieves autoinhibition and allows CARD8 to oligomerize and recruit CASP1. This process is distinct from NLRP1 inflammasome assembly, which involves a different domain architecture and activation mechanism. The resulting complex serves as a platform for CASP1 activation and downstream inflammatory signaling.
Regulation by DPP9
In simple terms: DPP9 acts as a brake on the CARD8 inflammasome.
DPP9 forms a ternary complex with CARD8 and regulates its activity, preventing premature inflammasome assembly. Disruption of the DPP9-mediated ternary complex by pathogen proteins, such as SFTSV non-structural protein, leads to CARD8 inflammasome activation. This regulatory mechanism highlights the tight control of CARD8 inflammasome under physiological conditions.
Key Genes Involved in GO:0140634 CARD8 inflammasome complex
The following genes and proteins are key components or regulators of the CARD8 inflammasome complex.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CARD8 | Sensor protein of the inflammasome complex | Central to activation and assembly |
| CASP1 | Effector caspase that induces pyroptosis | Mediates inflammatory cell death |
| DPP9 | Regulatory protease that inhibits CARD8 | Controls inflammasome activation |
| NLRP1 | Related inflammasome sensor | Comparative studies of inflammasome assembly |
| GSDMD | Gasdermin D, substrate of CASP1 | Executes pyroptosis |
| IL1B | Interleukin-1 beta, cytokine released upon inflammasome activation | Inflammatory mediator |
| IL18 | Interleukin-18, cytokine released upon inflammasome activation | Inflammatory mediator |
| HIV-1 protease | Viral protease that cleaves CARD8 | Triggers inflammasome activation |
| SFTSV NSP | Viral protein that disrupts DPP9-CARD8 complex | Activates CARD8 inflammasome |
| MEFV | Pyrin, related inflammasome sensor | Context for inflammasome diversity |
| NLRP3 | Well-studied inflammasome sensor | Comparative inflammasome biology |
| AIM2 | Cytosolic DNA sensor inflammasome | Comparative inflammasome biology |
| NLRC4 | Bacterial flagellin sensor inflammasome | Comparative inflammasome biology |
| PYCARD | ASC adaptor protein | Inflammasome signaling |
| CASP8 | Apoptotic caspase with inflammasome crosstalk | Cell death regulation |
| BIRC2/3 | Inhibitor of apoptosis proteins | CARD8 anti-apoptotic activity |
| NFKB1 | Transcription factor in inflammation | Inflammatory gene expression |
How Is CARD8 inflammasome complex Regulated?
The CARD8 inflammasome complex is tightly regulated by DPP9, which forms a ternary complex with CARD8 to prevent spontaneous activation. Disruption of this complex by pathogen-derived proteins, such as SFTSV non-structural protein, triggers inflammasome assembly. Additionally, CARD8 activity is controlled by proteolytic cleavage, particularly by HIV-1 protease, which removes an inhibitory domain. These regulatory mechanisms ensure that inflammasome activation is specific to pathogenic threats.
CARD8 inflammasome complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CARD8 | HIV-1 infection | Knockout cell lines, point mutation of cleavage site |
| CARD8 | Inflammatory disorders | Overexpression and knockout models |
| CASP1 | Pyroptosis-related diseases | Knockout and point mutation |
| DPP9 | Inflammasome regulation | Knockout and knock-in |
| GSDMD | Pyroptosis | Knockout and overexpression |
HIV-1 infection
CARD8 inflammasome is activated by HIV-1 protease, leading to pyroptosis of infected cells and limiting viral replication. This human-specific motif in CARD8 facilitates inflammasome activation after HIV-1 infection.
Inflammatory disorders
Dysregulated CARD8 inflammasome activity contributes to excessive inflammation and tissue damage in various inflammatory conditions. CARD8 has anti-inflammatory and anti-apoptotic activities, and its imbalance can lead to pathology.
Cancer
CARD8 inflammasome components are implicated in cancer biology, with potential roles in tumor suppression and immune surveillance. Modulation of inflammasome activity may affect tumor progression and response to immunotherapy.
Viral infections beyond HIV
SFTSV non-structural protein activates CARD8 inflammasome by disrupting DPP9-mediated ternary complex, highlighting its role in antiviral defense.
From CARD8 inflammasome complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does CARD8 cleavage trigger inflammasome assembly? | Point mutation of cleavage site |
| What is the role of DPP9 in CARD8 regulation? | Knockout of DPP9 |
| Can CARD8 inflammasome be activated by viral proteases? | Overexpression of viral protease |
| What is the structural basis of CARD8-CASP1 assembly? | Knock-in of tagged CARD8 |
| How does CARD8 affect pyroptosis? | Knockout of CARD8 in macrophages |
| Is CARD8 involved in cancer immunity? | Overexpression in tumor models |
How to Study the CARD8 inflammasome complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout screening | Gene essentiality for inflammasome activation | Identify regulators |
| Co-immunoprecipitation | Protein-protein interactions | Detect CARD8-CASP1 assembly |
| Western blot | Protein cleavage and activation | Monitor CARD8 processing |
| ELISA | Cytokine release | Measure IL-1beta and IL-18 |
| Flow cytometry | Pyroptosis and cell death | Quantify inflammasome activity |
| Fluorescence microscopy | Inflammasome speck formation | Visualize assembly |
| RNA-seq | Transcriptional changes | Inflammatory gene expression |
| Mass spectrometry | Proteomic composition | Identify complex components |
CRISPR screening
Genome-wide CRISPR knockout screens can identify genes that regulate CARD8 inflammasome activation, such as DPP9 and CASP1.
Proteomics
Affinity purification mass spectrometry can reveal components of the CARD8 inflammasome complex and its interactors.
Imaging
Fluorescence microscopy can visualize inflammasome assembly and pyroptosis in real time.
Functional assays
Cytokine release assays (IL-1beta, IL-18) and pyroptosis measurements are used to assess CARD8 inflammasome activity.
How CRISPR Can Be Used to Study GO:0140634 CARD8 inflammasome complex
Knockout
CRISPR knockout of CARD8 or CASP1 abolishes inflammasome function, providing a clean background to study activation mechanisms.
Point Mutation
Point mutations at the CARD8 cleavage site prevent HIV-1 protease-mediated activation, helping map the activation mechanism.
Knock-in
Knock-in of tagged CARD8 allows tracking of inflammasome assembly and localization in live cells.
Overexpression
Overexpression of CARD8 or viral proteases can induce constitutive inflammasome activation, useful for gain-of-function studies.
How EDITGENE Supports CARD8 inflammasome complex Research
Researchers studying CARD8 inflammasome complex-related genes often need to determine whether a candidate gene is causally involved in inflammasome activation, pyroptosis, or inflammatory signaling. EDITGENE provides a comprehensive suite of CRISPR services to enable such functional studies.
Contact EDITGENE today to design your custom CRISPR model for CARD8 inflammasome complex research.
Frequently Asked Questions About CARD8 inflammasome complex
What is the CARD8 inflammasome complex?
It is a cellular component (GO:0140634) consisting of CARD8 and CASP1 that activates inflammatory responses.
What genes are involved in the CARD8 inflammasome complex?
Key genes include CARD8, CASP1, DPP9, GSDMD, IL1B, and IL18.
How is the CARD8 inflammasome activated?
It is activated by proteolytic cleavage of CARD8, often by pathogen proteases like HIV-1 protease.
What diseases are associated with CARD8 inflammasome?
HIV-1 infection, inflammatory disorders, and cancer.
What is the role of DPP9 in CARD8 inflammasome?
DPP9 inhibits CARD8 by forming a ternary complex, preventing premature activation.
How can I study CARD8 inflammasome using CRISPR?
Use knockout, point mutation, knock-in, or overexpression models to dissect its function.
What are the symptoms of CARD8 inflammasome dysregulation?
Excessive inflammation, pyroptosis, and tissue damage.
Is CARD8 inflammasome a therapeutic target?
Yes, it is being explored for inflammatory diseases and cancer.
What cell types express CARD8 inflammasome?
It is expressed in immune cells such as macrophages and monocytes.
How does CARD8 differ from NLRP1?
CARD8 and NLRP1 have distinct structural domains and assembly mechanisms.
Conclusion
The CARD8 inflammasome complex (GO:0140634) is a critical innate immune sensor that detects pathogen-derived proteases and triggers pyroptosis. Its unique composition and regulation by DPP9 offer insights into inflammasome diversity. CRISPR-based models are indispensable for advancing our understanding of CARD8 biology and its role in disease.
References
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- 2. Liu PP et al.. 2025. The non-structural protein of SFTSV activates NLRP1 and CARD8 inflammasome through disrupting the DPP9-mediated ternary complex.. PLoS Pathog 21(7):e1013258 PMID: 40608794
- 3. Karakaya T et al.. 2024. CARD8: A Novel Inflammasome Sensor with Well-Known Anti-Inflammatory and Anti-Apoptotic Activity.. Cells 13(12) PMID: 38920661
- 4. Gong Q et al.. 2021. Structural basis for distinct inflammasome complex assembly by human NLRP1 and CARD8.. Nat Commun 12(1):188 PMID: 33420028
- 5. Pandey A et al.. 2025. Molecular mechanisms of emerging inflammasome complexes and their activation and signaling in inflammation and pyroptosis.. Immunol Rev 329(1):e13406 PMID: 39351983
- 6. Taabazuing CY et al.. 2020. The NLRP1 and CARD8 inflammasomes.. Immunol Rev 297(1):13-25 PMID: 32558991
- 7. Dubey SR et al.. 2025. Molecular mechanisms and regulation of inflammasome activation and signaling: sensing of pathogens and damage molecular patterns.. Cell Mol Immunol 22(11):1313-1344 PMID: 41062723
- 8. Kulsuptrakul J et al.. 2023. A human-specific motif facilitates CARD8 inflammasome activation after HIV-1 infection.. Elife 12 PMID: 37417868
