WikiJournal Preprints/Inflammasomes: Role in health and disease

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Article information

Abstract

Inflammasomes are protein complexes that contribute to immunity and inflammation in the body. The inflammasome protein complex consists of a sensor protein, inflammatory caspases, and an adaptor protein. Various endogenous and exogenous stimuli can activate inflammasomes, resulting in the enzymatic activation of mostly caspase-1 and the release of IL-1β and IL-18, as well as pyroptosis, a form of cell death. Some inflammasomes have been described, including NLRP3, NLRP1, AIM2, NLRC4, and pyrin. The assembly of NLRP3, AIM2, and pyrin inflammasomes highly depends on the ASC protein adaptor. As for NLRP1 and NLRC4, since both have a CARD domain, they can induce inflammasome assembly and pyroptosis independently of ASC. Some bacterial and viral products reside within the host cell cytoplasm, which will be recognized by the molecules sensor NLR, AIM2, and pyrin. The sensors further recruit ASC to form a multimeric complex, which then recruits procaspase-1 into the complex. Subsequently, procaspase-1 is converted into active caspase-1. The active caspase-1 subunit cleaves pro-IL-1β and pro-IL-18 to produce IL-1β and IL-18 cytokines and activates gasdermin D, a pore-forming molecule. That is the common and accepted (canonical) pathway. However, a non-canonical pathway also occurs downstream of caspase-11 cleavage. Proper activation of inflammasomes is crucial for the host as immunity against pathogens or tissue damage. However, aberrant activation of inflammasomes can lead to uncontrolled tissue responses that contribute to various diseases, such as autoinflammatory disorders, gout, CAPS syndrome, and neurodegenerative diseases. Efforts to find inflammasome-targeted drugs are still ongoing; one that has entered clinical trials is dapansutril for the treatment of gout.


Discovery

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The term "inflammasome" was introduced by Martinon et al. in 2002 that described the assembly of large complex structures in the cytoplasm of activated immune cells, leading to proteolytic activation of proinflammatory caspases, which drive immune response and inflammation.[1]

Inflammasome assembly

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Inflammasome structure (attribution: Aiyaya, CC BY-SA 3.0)

Inflammation occurs when the immune system sends signaling molecules and white blood cells to the site of injury to fight bacteria, viruses, and other pathogens and help repair damaged tissue. During infection, the innate immune response employs a form of first defense through a cluster of pattern recognition receptors (PRRs) to recognize pathogen-associated molecules, pathogen-associated molecular patterns (PAMPs), and damage-associated molecular patterns (DAMPs) generated by the host. PRRs can be membrane-expressed receptors, such as a Toll-like receptor (TLR), or cytoplasmic NOD-like receptors (NLR). The inflammasome complex is activated by a subset of cytosolic PRRs that recognize various PAMPs and DAMPs.[2]

PAMP and DAMP sensors in the cytoplasm are NLR, AIM2, and pyrin. Inflammasomes typically consist of sensors, adaptor molecule ASC, and procaspase-1. Upon detecting certain stimuli, the sensor recruits ASC to form a multimeric complex, which then recruits procaspase-1 into the complex. Subsequently, procaspase-1 is converted into active caspase-1 through proximity-induced cleavage. Following this, the active caspase-1 subunits, p20 and p10, cleave pro-IL-1β and pro-IL-18 to produce the cytokines IL-1β and IL-18, and activate gasdermin D, a pore-forming molecule, to induce a form of cell death called "pyroptosis."[3]

All members of the NLR family contain a nucleotide-binding domain (NBD) and a C-terminal LRR domain. Based on the presence of N-terminal, pyrin (PYD) or CARD domains, NLRs can be further divided into NLRP and NLRC receptors. The human and mouse genomes encode 22 and 34 NLRs, respectively.[4] Of these proteins, NLRP1, NLRP3 and NLRC4 are known to induce inflammasome formation to activate caspase-1. Other NLR members, namely NLRP12, NLRP6, and NLRP9b can also form inflammasomes,[5] but research in their function as inflammasome sensors is ongoing.

Inflammasome assembly requires homotypic (binding of other proteins of the same type) CARD-CARD or PYD-PYD interactions between the constituent components. Furthermore, either CARD or PYD can induce oligomerization which is the basis of inflammasome assembly. When a ligand is detected, the sensor is released from the inhibitory state and oligomerizes ASC by inducing homotypic interactions between the PYD domain. Subsequently, ASC recruits pro-caspase-1 through interactions between its CARD domains.

The assembly of NLRP3, AIM2, and pyrin inflammasomes highly depend on the adaptor protein ASC. Since NLRP1 and NLRC4 have a CARD domain, they can directly recruit caspase-1.[6] In other words, NLRP1 and NLRC4 can induce inflammasome assembly and pyroptosis independently of ASC.[7]

Inflammasome family

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Some inflammasomes have been described, including NLRP3, NLRP1, AIM2, NAIP-NLRC4, and pyrin.[8] The NLRP3 inflammasome consists of the NLRP3 molecule sensor, the ASC protein adaptor, and pro-caspase-1. The AIM2 inflammasomes sense cytosolic DNA through its C-terminal HIN200 domain and can recruit pro-caspase-1 through ASC to form the AIM2-ASC-pro-caspase-1 complex.[9] Unlike NLRP3 and AIM2, NLRP1 protein contains PYD and CARD domains, which interact directly with pro-caspase-1 without the adaptor protein ASC, but the presence of ASC can enhance NLRP1-mediated caspase-1 activation.[10] NLRC4 has only a CARD domain, which recruits pro-caspase-1 directly in the absence of ASC to form NLRC4 inflammasomes.[11]

Inflammasome NLRP3

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By far the most studied NLR is NLRP3. NLRP3, also known as cryopyrin and NALP3, is upregulated in response to macrophage stimulation by PAMPs (e.g., lipopolysaccharide, LPS) or inflammatory cytokines (e.g., TNF-α).[12]

The NLRP3 gene encodes the protein cryopyrin. NLRP3 lacks a caspase recruitment domain (CARD) and thus cannot recruit procaspase-1 except in the presence of the adaptor molecule ASC. Cryopyrin is a member of a family of proteins called intracellular "NOD-like" receptor (NLR) proteins. Cryopyrin is found mainly in white blood cells and cartilage-forming cells (chondrocytes). Cryopyrin recognizes bacteria; chemicals such as asbestos, silica, and uric acid crystals; and compounds released by injured cells.

NLRP3 inflammasomes can be activated by the pore-forming activity of a broad spectrum of Gram-positive and Gram-negative bacteria, especially by triggering potassium (K+) secretion.

Inflammasome NLRP1

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NLRP1 is expressed in adaptive immune cells and tissues as well as in non-hematopoietic tissues.[13] Unlike other NLRs, the NLRP1 sensor contains function-to-find (FIIND) and CARD domains, in addition to PYD, NBD, and LRR domains.[14] Oligomerized NLRP1 can directly recruit caspase-1 through its CARD domain and can be further enhanced by binding to ASC through its pyrin domain (PYD).[10] The mouse genome encodes three NLRP1 paralogs (NLRP1a, NLRP1b, NLRP1c), all of which lack the PYD. NLRP1b is activated by cleavage at the N terminus and FIIND domain by lethal factor (LF), a component of anthrax lethal toxin (LeTx) produced by Bacillus anthracis.[15] This activation of NLRP1b by LeTx has been shown to protect mice from Bacillus anthracis infection.[16]

Inflammasome AIM2

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AIM2 also known as PYHIN4, is a member of the PYHIN family (containing a Pyrin domain and a HIN200 domain). AIM2 is an interferon-inducible gene. AIM2 (absent in melanoma 2) was initially identified during functional screening for tumor suppressor genes in melanoma.[17] AIM2 does not belong to the NLR proteins, but several research groups identified AIM2 as a component of the inflammasomes.[18]

AIM2 can form inflammasomes whose assembly is stimulated by cytosolic DNA recognition from bacteria or viruses or DNA from apoptotic cells. The binding of DNA to the HIN domain results in a conformational change and oligomerization of AIM2 around the DNA molecule, which further enables recruitment of ASC and caspase-1 to form stable inflammasomes.[19] Similar to NLR inflammasomes, AIM2 inflammasomes result in IL-1β and IL-18 secretion, as well as cell death.

Inflammasome NAIP-NLRC4

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NLRC4 is expressed mainly in hematopoietic tissues and cells. NLRC4 has a CARD domain so that it can interact directly with procaspase-1 through homotypic CARD-CARD binding leading to caspase-1 processing, and this process can be independent of ASC.[20] NLRC4 is activated in response to many pathogenic bacteria, including Salmonella typhimurium and Pseudomonas aeruginosa. NLRC4 acts as a sensor for bacterial flagellin or structural components of type III bacterial secretion system (T3SS).[21] However, NLRC4 is not a direct sensor of these ligands. The system uses NAIP (NLR-family apoptosis-inhibiting protein) in the cytosol as a sensor of NLRC4 ligands, so NAIP is essential for NLRC4 inflammasome activation. In humans, one NAIP has been identified.[22]

Inflammasome Pyrin

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In humans, pyrin consists of an N-terminal PYD, a central B-box, a coiled-coil domain, and a C-terminal B30.2/SPRY domain. Study shows that pyrin inflammasomes are assembled on modified cytoskeletal proteins. Toxins produced by various bacterial species, such as Clostridium difficile (TcdB), Clostridium botulinum (C3), Vibrio parahemolyticus (VopS), Burkholderia cenocepacia, and Bordetella pertussis (PT), induce covalent modifications of Rho family members. These modifications include glycosylation, adenylation, and ribosylation of ADP, and lead to the assembly of pyrin inflammasomes.[23]

Inflammasome activation

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Some pathways for inflammasome activation have been identified.[24]

NLRP3 inflammation activation

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NLRP3 inflammasomes are activated by diverse endogenous and exogenous agonists, including PAMPs and toxins from bacterial, fungal, and protozoan pathogens, as well as DAMPs such as ATP, uric acid crystals, and β-amyloid fibrils.[25] For NLRP3 inflammasome activation, a two-signal model has been proposed; the first signal is referred to as priming, while the second is aimed at inflammasome assembly. In the model, the first signal is provided by microbial components or endogenous cytokines, while the second signal is from extracellular ATP, pore-forming toxins, or particulate matter.[26]

Signal 1 involves activation of the MyD88 activating pathway or other transcription factors (e.g., NF-κB), which upregulates the expression of Nlrp3 and other inflammasome components. Signal 2 involves multiple molecular signaling events induced by NLRP3 stimuli, including potassium ion efflux, mitochondrial dysfunction, and reactive oxygen species (ROS) production.[26][27] Cytosolic potassium ion efflux is a common trigger in NLRP3 inflammasome activation. NEK7 (NIMA-related kinase 7), a mitosis-associated serine-threonine kinase, acts as an NLRP3-binding protein through interactions between their respective LRR domains. NEK7 acts downstream of potassium ion release to regulate oligomerization and activation of NLRP3 inflammasomes.[28] Mitochondrial dysfunction is another trigger in NLRP3 activation through mitochondrial DNA (mtDNA) shedding, mitophagy, and apoptosis.[29] Meanwhile, ROS induces the binding of thioredoxin-interacting proteins to NLRP3, which is important for NLRP3 inflammasome activation.[30]

Non-canonical activation

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A common and accepted (canonical) pathway in inflammasome activation is the recruitment of caspase-1 in response to PAMPs or DAMPs. However, there is also a non-canonical pathway where NLRP3 inflammasomes activation occurs downstream of the cleavage of caspase-11 (or caspase-4 and caspase-5 in humans) and gasdermin D. In non-canonical inflammasomes signaling, caspase-11 acts as an LPS sensor in the cytosol.[31] Upon recognizing LPS, caspase-11 initiates IL-1β proteolytic maturation and gasdermin D-dependent pyroptotic cell death. Caspase-11 directly binds to LPS via the CARD domain. Caspase-11 signaling engages the NLRP3 inflammasomes, thereby cross-recruiting caspase-1 signaling and inducing the maturation of IL-1β and IL-18.[32]

Regulator of inflammation activation

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Activation of NLRP3 inflammasomes is mostly beneficial for host immunity, but excessive production of IL-1β and IL-18 can result in sterile inflammation that may increase the risk of metabolic diseases and autoinflammation. Therefore, activation of the NLRP3 inflammasome must be appropriately controlled through binding proteins and post-translational modifications.

Members of the POP (pyrin-only protein) family, including POP116 and POP216, block inflammasome assembly by binding to ASCs and inhibiting ASC recruitment to NLRP3.[33][34] Negative regulatory molecules that target ion depletion, mitochondrial function, and ROS signaling can also block NLRP3 inflammasome activation. For example, the ketone body compound β-hydroxybutyrate can inhibit NLRP3 inflammasome-mediated inflammation by preventing the release of potassium ions.[35]

Post-translational modifications of NLRP3, including ubiquitination and deubiquitination, can also suppress or activate inflammasome activation.[36] During the activation step, phosphorylation of NLRP3 by Golgi-mediated protein kinase D (PKD) at Ser293 (or human Ser295) can trigger inflammasome assembly.[37] In contrast, phosphorylation of NLRP3 by PKA at Ser 291 of mice mediates the negative regulation of bile acids-induced NLRP3 inflammasomes.[38] In addition to phosphorylating enzymes, deubiquitinating enzymes are also involved in inflammasome regulation. For example, BRCC3 promotes inflammasome activation by deubiquitinating NLRP3 at the LRR domain.[39] ABRO1, a component of the BRCC3 complex, can enhance NLRP3 inflammasome activation by regulating NLRP3 deubiquitination after LPS induction.[40]

Role in health

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Antimicrobial immunity

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The main effects of inflammasome activation are pyroptosis and/or secretion of IL-1β and IL-18, which protect against microorganisms invading the body. Inflammasome proteins are expressed mainly by macrophages and dendritic cells. The intestines and lungs are the main tissues and cells involved in inflammasome-mediated immunity against microbial infection.[25] Epithelial cells are essential lining cells on these body surfaces, and inflammasomes are known to be involved in defense there.[41] In the case of antiviral defense, NLRP3 inflammasomes have been known to be involved in inhibiting viral replication.[42]

Comensal microbial

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Inflammasomes may also play a role in shaping gut microbiota composition. NLRP6-deficient mice have altered gut microbiota composition characterized by the presence of Prevotellaceae species and become more susceptible to colitis. These changes in microbial composition and susceptibility to colitis can be transmitted to normal mice, indicating that changes in the gut microbiota mediate this phenotype. NLRP6 inflammasome assembly and IL-18 secretion are required to maintain gut hemostasis through the regulation of microbiota composition, and the absence of NLRP6 inflammasomes leads to the expansion of potentially pathogenic microbiota members.[43][44]

Pyroptosis cell death

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Pyroptosis is a form of cell death induced by inflammasome activation, characterized by cell swelling followed by lysis and release of intracellular contents. Gasdermin D has been identified as a link between cell death and activation of caspase-1 and/or caspase-11.[45] Pyroptotic caspases 1 and 11 (caspase-4 and caspase-5 in humans) cleave Gasdermin D at D276 in the binding region, thereby eliminating the intramolecular inhibitory effect of the C-terminus domain. Upon binding to membrane lipids, the N end region of Gasdermin D (GSDMD-N) oligomerizes to form pores with an inner diameter of 10 to 18 nm.[46] The formation of these pores disrupts the osmotic potential of the cell, thereby causing swelling and lysis. Expression of the N end fragment is also sufficient to kill bacterial cells.[47]

Role in disease

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CAPS disease

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Mutations in NLRP3 cause cryopyrin-associated periodic syndromes (CAPS), a disease mediated mainly by cytokines from the innate immune system, especially IL-1β.[48] The signs and symptoms of CAPS affect several body systems. CAPS is commonly characterized by episodes of skin rash, fever, and joint pain.[49] These episodes may be triggered by exposure to cold temperatures, fatigue, other stressors, or may arise spontaneously. Episodes may last from a few hours to several days. These episodes usually begin in infancy or early childhood and persist throughout life. CAPS patients respond positively when treated with IL-1 blockers, suggesting that inappropriate IL-1β production by the NLRP3 inflammasome is a driver of CAPS development.[50]

Gout

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Gout, also called uric acid disease, is when crystals of monosodium urate (MSU) accumulate in the joints and cause painful inflammation. Studies show that the mechanism of the MSU-induced inflammatory response depends on the proinflammatory cytokine IL-1β. This IL-1-dependent inflammatory phenotype is now understood to depend on the formation of NLRP3 inflammasomes in response to the 'danger signal' of uric acid crystals.[51] In the absence of NLRP3 inflammasome components, macrophages cannot secrete active IL-1β following stimulation with MSU and calcium pyrophosphate crystal dihydrate.[52]

During the initiation phase, MSU crystals are deposited within the joint stimulate extracellular TLRs expressed by the monocytes resident, leading to the transcription of pro-IL-1β.[51] MSU crystals are also phagocytosed by resident monocytes, which is positively regulated by TLR activation,[53] resulting in oligomerization of the NLRP3 inflammasome, activation of caspase-1, and cleavage of pro-IL-1β into active IL-1β.

NLRP3 inflammasome inhibitor

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The involvement of NLRP3 inflammasomes in various diseases encourages researchers to find NLRP3-targeted drugs. Clinical treatment of NLRP3-related diseases has only used IL-1β antibodies or recombinant IL-1β receptor antagonists, such as canakinumab and anakinra. However, these inhibitors have the disadvantage that inflammatory diseases do not only involve IL-1β as a cause. In addition, IL-1β can be produced by an inflammasome-independent pathway,[54][55] and this cytokine can also be produced from other types of inflammasomes. Therefore, inhibitors targeting IL-1β may cause unwanted immunosuppressive effects.[27]

Several small molecule compounds have shown anti-inflammatory effects on NLRP3 inflammasome activation in vitro, including MCC95090, β-hydroxybutyrate, Bay 11-7082, dimethyl sulfoxide (DMSO), and type I interferon.[56]

Dapansutril (OLT1177), an orally active β-sulfonyl nitrile compound, is a newly developed drug that inhibits the NLRP3 inflammasome. Nanomolar concentrations of OLT1177 reduced the release of IL-1β and IL-18 after activation of canonical and non-canonical NLRP3 inflammasomes. The molecule showed no effect on NLRC4 and AIM2 inflammasomes, suggesting specificity for NLRP3.[57] In phase 2a clinical trials, dapansutril demonstrated a good safety profile and efficacy in reducing target joint pain.[58]

Additional information

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Acknowledgements

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The author acknowledge the support of Dicky Rizky Febrian during preparing this manuscript.

Competing interests

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None.

Ethics statement

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No animal or human was involved as research subject.

References

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  1. Martinon, Fabio; Burns, Kimberly; Tschopp, Jürg (2002-08-01). "The Inflammasome: A Molecular Platform Triggering Activation of Inflammatory Caspases and Processing of proIL-β". Molecular Cell 10 (2): 417–426. doi:10.1016/S1097-2765(02)00599-3. ISSN 1097-2765. PMID 12191486. https://www.cell.com/molecular-cell/abstract/S1097-2765(02)00599-3. 
  2. Bianchi, Marco E. (2007-01). "DAMPs, PAMPs and alarmins: all we need to know about danger". Journal of Leukocyte Biology 81 (1): 1–5. doi:10.1189/jlb.0306164. http://doi.wiley.com/10.1189/jlb.0306164. 
  3. Malik, Ankit; Kanneganti, Thirumala-Devi (2017-12-01). "Inflammasome activation and assembly at a glance". Journal of Cell Science 130 (23): 3955–3963. doi:10.1242/jcs.207365. ISSN 1477-9137. PMID 29196474. PMC PMC5769591. https://doi.org/10.1242/jcs.207365. 
  4. Harton, Jonathan A.; Linhoff, Michael W.; Zhang, Jinghua; Ting, Jenny P.-Y. (2002-10-15). "Cutting Edge: CATERPILLER: A Large Family of Mammalian Genes Containing CARD, Pyrin, Nucleotide-Binding, and Leucine-Rich Repeat Domains". The Journal of Immunology 169 (8): 4088–4093. doi:10.4049/jimmunol.169.8.4088. ISSN 0022-1767. PMID 12370334. https://www.jimmunol.org/content/169/8/4088. 
  5. Vladimer, Gregory I.; Weng, Dan; Paquette, Sara W. Montminy; Vanaja, Sivapriya Kailasan; Rathinam, Vijay A. K.; Aune, Marie Hjelmseth; Conlon, Joseph E.; Burbage, Joseph J. et al. (2012-07-27). "The NLRP12 Inflammasome Recognizes Yersinia pestis". Immunity 37 (1): 96–107. doi:10.1016/j.immuni.2012.07.006. ISSN 1074-7613. PMID 22840842. PMC PMC3753114. https://www.cell.com/immunity/abstract/S1074-7613(12)00286-5. 
  6. Nour, Adel M.; Yeung, Yee-Guide; Santambrogio, Laura; Boyden, Eric D.; Stanley, E. Richard; Brojatsch, Jürgen (2009-03). "Anthrax Lethal Toxin Triggers the Formation of a Membrane-Associated Inflammasome Complex in Murine Macrophages". Infection and Immunity 77 (3): 1262–1271. doi:10.1128/IAI.01032-08. ISSN 0019-9567. PMID 19124602. PMC PMC2643637. https://journals.asm.org/doi/10.1128/IAI.01032-08. 
  7. Van Opdenbosch, Nina; Gurung, Prajwal; Vande Walle, Lieselotte; Fossoul, Amelie; Kanneganti, Thirumala-Devi; Lamkanfi, Mohamed (2014-02-04). "Activation of the NLRP1b inflammasome independently of ASC-mediated caspase-1 autoproteolysis and speck formation". Nature Communications 5 (1): 3209. doi:10.1038/ncomms4209. ISSN 2041-1723. PMID 24492532. PMC PMC3926011. https://www.nature.com/articles/ncomms4209. 
  8. Hayward, Jenni A.; Mathur, Anukriti; Ngo, Chinh; Man, Si Ming (2018-12). "Cytosolic Recognition of Microbes and Pathogens: Inflammasomes in Action". Microbiology and Molecular Biology Reviews 82 (4): e00015–18. doi:10.1128/MMBR.00015-18. ISSN 1092-2172. PMID 30209070. PMC PMC6298609. https://journals.asm.org/doi/10.1128/MMBR.00015-18. 
  9. Rathinam, Vijay A. K.; Jiang, Zhaozhao; Waggoner, Stephen N.; Sharma, Shruti; Cole, Leah E.; Waggoner, Lisa; Vanaja, Sivapriya Kailasan; Monks, Brian G. et al. (2010-05). "The AIM2 inflammasome is essential for host defense against cytosolic bacteria and DNA viruses". Nature Immunology 11 (5): 395–402. doi:10.1038/ni.1864. ISSN 1529-2916. PMID 20351692. PMC PMC2887480. https://www.nature.com/articles/ni.1864. 
  10. 10.0 10.1 Faustin, Benjamin; Lartigue, Lydia; Bruey, Jean-Marie; Luciano, Frederic; Sergienko, Eduard; Bailly-Maitre, Beatrice; Volkmann, Niels; Hanein, Dorit et al. (2007-03-09). "Reconstituted NALP1 Inflammasome Reveals Two-Step Mechanism of Caspase-1 Activation". Molecular Cell 25 (5): 713–724. doi:10.1016/j.molcel.2007.01.032. ISSN 1097-2765. PMID 17349957. https://www.cell.com/molecular-cell/abstract/S1097-2765(07)00078-0. 
  11. Kesavardhana, Sannula; Kanneganti, Thirumala-Devi (2017-05-01). "Mechanisms governing inflammasome activation, assembly and pyroptosis induction". International Immunology 29 (5): 201–210. doi:10.1093/intimm/dxx018. ISSN 0953-8178. PMID 28531279. PMC PMC5890894. https://doi.org/10.1093/intimm/dxx018. 
  12. Bauernfeind, Franz G.; Horvath, Gabor; Stutz, Andrea; Alnemri, Emad S.; MacDonald, Kelly; Speert, David; Fernandes-Alnemri, Teresa; Wu, Jianghong et al. (2009-07-15). "Cutting Edge: NF-κB Activating Pattern Recognition and Cytokine Receptors License NLRP3 Inflammasome Activation by Regulating NLRP3 Expression". The Journal of Immunology 183 (2): 787–791. doi:10.4049/jimmunol.0901363. ISSN 0022-1767. PMID 19570822. PMC PMC2824855. https://www.jimmunol.org/content/183/2/787. 
  13. Kummer, J. Alain; Broekhuizen, Roel; Everett, Helen; Agostini, Laetitia; Kuijk, Loes; Martinon, Fabio; Bruggen, Robin van; Tschopp, Jürg (2007-05). "Inflammasome Components NALP 1 and 3 Show Distinct but Separate Expression Profiles in Human Tissues Suggesting a Site-specific Role in the Inflammatory Response". Journal of Histochemistry & Cytochemistry 55 (5): 443–452. doi:10.1369/jhc.6A7101.2006. ISSN 0022-1554. http://journals.sagepub.com/doi/10.1369/jhc.6A7101.2006. 
  14. Finger, Joshua N.; Lich, John D.; Dare, Lauren C.; Cook, Michael N.; Brown, Kristin K.; Duraiswami, Chaya; Bertin, John J.; Gough, Peter J. (2012-07-20). "Autolytic Proteolysis within the Function to Find Domain (FIIND) Is Required for NLRP1 Inflammasome Activity *". Journal of Biological Chemistry 287 (30): 25030–25037. doi:10.1074/jbc.M112.378323. ISSN 0021-9258. PMID 22665479. PMC PMC3408201. https://www.jbc.org/article/S0021-9258(20)73673-2/abstract. 
  15. Chavarría-Smith, Joseph; Vance, Russell E. (2013-06-20). "Direct Proteolytic Cleavage of NLRP1B Is Necessary and Sufficient for Inflammasome Activation by Anthrax Lethal Factor". PLOS Pathogens 9 (6): e1003452. doi:10.1371/journal.ppat.1003452. ISSN 1553-7374. PMID 23818853. PMC PMC3688554. https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1003452. 
  16. Terra, Jill K.; Cote, Christopher K.; France, Bryan; Jenkins, Amy L.; Bozue, Joel A.; Welkos, Susan L.; LeVine, Steven M.; Bradley, Kenneth A. (2010-01-01). "Cutting Edge: Resistance to Bacillus anthracis Infection Mediated by a Lethal Toxin Sensitive Allele of Nalp1b/Nlrp1b". The Journal of Immunology 184 (1): 17–20. doi:10.4049/jimmunol.0903114. ISSN 0022-1767. PMID 19949100. PMC PMC2811128. https://www.jimmunol.org/content/184/1/17. 
  17. DeYoung, Katherine L.; Ray, Michael E.; Su, Yan A.; Anzick, Sarah L.; Johnstone, Ricky W.; Trapani, Joseph A.; Meltzer, Paul S.; Trent, Jeffrey M. (1997-07). "Cloning a novel member of the human interferon-inducible gene family associated with control of tumorigenicity in a model of human melanoma". Oncogene 15 (4): 453–457. doi:10.1038/sj.onc.1201206. ISSN 1476-5594. https://www.nature.com/articles/1201206. 
  18. Lugrin, Jérôme; Martinon, Fabio (2018-01). "The AIM2 inflammasome: Sensor of pathogens and cellular perturbations". Immunological Reviews 281 (1): 99–114. doi:10.1111/imr.12618. https://onlinelibrary.wiley.com/doi/10.1111/imr.12618. 
  19. Jin, Tengchuan; Perry, Andrew; Smith, Patrick; Jiang, Jiansheng; Xiao, T. Sam (2013-05-10). "Structure of the Absent in Melanoma 2 (AIM2) Pyrin Domain Provides Insights into the Mechanisms of AIM2 Autoinhibition and Inflammasome Assembly *". Journal of Biological Chemistry 288 (19): 13225–13235. doi:10.1074/jbc.M113.468033. ISSN 0021-9258. PMID 23530044. PMC PMC3650362. https://www.jbc.org/article/S0021-9258(19)54554-9/abstract. 
  20. Poyet, Jean-Luc; Srinivasula, Srinivasa M.; Tnani, Mehdi; Razmara, Marjaneh; Fernandes-Alnemri, Teresa; Alnemri, Emad S. (2001-07-27). "Identification of Ipaf, a Human Caspase-1-activating Protein Related to Apaf-1 *". Journal of Biological Chemistry 276 (30): 28309–28313. doi:10.1074/jbc.C100250200. ISSN 0021-9258. PMID 11390368. https://www.jbc.org/article/S0021-9258(19)31640-0/abstract. 
  21. Miao, Edward A.; Mao, Dat P.; Yudkovsky, Natalya; Bonneau, Richard; Lorang, Cynthia G.; Warren, Sarah E.; Leaf, Irina A.; Aderem, Alan (2010-02-16). "Innate immune detection of the type III secretion apparatus through the NLRC4 inflammasome". Proceedings of the National Academy of Sciences 107 (7): 3076–3080. doi:10.1073/pnas.0913087107. ISSN 0027-8424. PMID 20133635. PMC PMC2840275. https://pnas.org/doi/full/10.1073/pnas.0913087107. 
  22. Endrizzi, Matthew G.; Hadinoto, Vey; Growney, Joseph D.; Miller, Webb; Dietrich, William F. (2000-08-01). "Genomic Sequence Analysis of the Mouse Naip Gene Array". Genome Research 10 (8): 1095–1102. doi:10.1101/gr.10.8.1095. ISSN 1088-9051. PMID 10958627. PMC PMC310933. https://genome.cshlp.org/content/10/8/1095. 
  23. Xu, Hao; Yang, Jieling; Gao, Wenqing; Li, Lin; Li, Peng; Zhang, Li; Gong, Yi-Nan; Peng, Xiaolan et al. (2014-09). "Innate immune sensing of bacterial modifications of Rho GTPases by the Pyrin inflammasome". Nature 513 (7517): 237–241. doi:10.1038/nature13449. ISSN 1476-4687. https://www.nature.com/articles/nature13449. 
  24. Man, Si Ming; Kanneganti, Thirumala-Devi (2015-05). "Regulation of inflammasome activation". Immunological Reviews 265 (1): 6–21. doi:10.1111/imr.12296. PMID 25879280. PMC PMC4400844. https://onlinelibrary.wiley.com/doi/10.1111/imr.12296. 
  25. 25.0 25.1 Zoete, Marcel R. de; Palm, Noah W.; Zhu, Shu; Flavell, Richard A. (2014-12-01). "Inflammasomes". Cold Spring Harbor Perspectives in Biology 6 (12): a016287. doi:10.1101/cshperspect.a016287. ISSN 1943-0264. PMID 25324215. PMC PMC4292152. http://cshperspectives.cshlp.org/content/6/12/a016287. 
  26. 26.0 26.1 Kelley, Nathan; Jeltema, Devon; Duan, Yanhui; He, Yuan (2019-01). "The NLRP3 Inflammasome: An Overview of Mechanisms of Activation and Regulation". International Journal of Molecular Sciences 20 (13): 3328. doi:10.3390/ijms20133328. ISSN 1422-0067. PMID 31284572. PMC PMC6651423. https://www.mdpi.com/1422-0067/20/13/3328. 
  27. 27.0 27.1 Yang, Yang; Wang, Huanan; Kouadir, Mohammed; Song, Houhui; Shi, Fushan (2019-02-12). "Recent advances in the mechanisms of NLRP3 inflammasome activation and its inhibitors". Cell Death & Disease 10 (2): 1–11. doi:10.1038/s41419-019-1413-8. ISSN 2041-4889. PMID 30755589. PMC PMC6372664. https://www.nature.com/articles/s41419-019-1413-8. 
  28. He, Yuan; Zeng, Melody Y.; Yang, Dahai; Motro, Benny; Núñez, Gabriel (2016-02). "NEK7 is an essential mediator of NLRP3 activation downstream of potassium efflux". Nature 530 (7590): 354–357. doi:10.1038/nature16959. ISSN 1476-4687. PMID 26814970. PMC PMC4810788. https://www.nature.com/articles/nature16959. 
  29. Zhong, Zhenyu; Liang, Shuang; Sanchez-Lopez, Elsa; He, Feng; Shalapour, Shabnam; Lin, Xue-jia; Wong, Jerry; Ding, Siyuan et al. (2018-08). "New mitochondrial DNA synthesis enables NLRP3 inflammasome activation". Nature 560 (7717): 198–203. doi:10.1038/s41586-018-0372-z. ISSN 1476-4687. PMID 30046112. PMC PMC6329306. https://www.nature.com/articles/s41586-018-0372-z. 
  30. Xiao, Ye Da; Huang, Ya Yi; Wang, Hua Xin; Wu, Yang; Leng, Yan; Liu, Min; Sun, Qian; Xia, Zhong-Yuan (2016-10-27). "Thioredoxin-Interacting Protein Mediates NLRP3 Inflammasome Activation Involved in the Susceptibility to Ischemic Acute Kidney Injury in Diabetes". Oxidative Medicine and Cellular Longevity 2016: e2386068. doi:10.1155/2016/2386068. ISSN 1942-0900. PMID 27867451. PMC PMC5102753. https://www.hindawi.com/journals/omcl/2016/2386068/. 
  31. Kayagaki, Nobuhiko; Warming, Søren; Lamkanfi, Mohamed; Walle, Lieselotte Vande; Louie, Salina; Dong, Jennifer; Newton, Kim; Qu, Yan et al. (2011-11). "Non-canonical inflammasome activation targets caspase-11". Nature 479 (7371): 117–121. doi:10.1038/nature10558. ISSN 1476-4687. https://www.nature.com/articles/nature10558. 
  32. Kayagaki, Nobuhiko; Stowe, Irma B.; Lee, Bettina L.; O’Rourke, Karen; Anderson, Keith; Warming, Søren; Cuellar, Trinna; Haley, Benjamin et al. (2015-10). "Caspase-11 cleaves gasdermin D for non-canonical inflammasome signalling". Nature 526 (7575): 666–671. doi:10.1038/nature15541. ISSN 1476-4687. https://www.nature.com/articles/nature15541. 
  33. de Almeida, Lucia; Khare, Sonal; Misharin, Alexander V.; Patel, Rajul; Ratsimandresy, Rojo A.; Wallin, Melissa C.; Perlman, Harris; Greaves, David R. et al. (2015-08-18). "The PYRIN Domain-only Protein POP1 Inhibits Inflammasome Assembly and Ameliorates Inflammatory Disease". Immunity 43 (2): 264–276. doi:10.1016/j.immuni.2015.07.018. ISSN 1074-7613. PMID 26275995. PMC PMC4666005. https://www.cell.com/immunity/abstract/S1074-7613(15)00307-6. 
  34. Ratsimandresy, Rojo A.; Chu, Lan H.; Khare, Sonal; de Almeida, Lucia; Gangopadhyay, Anu; Indramohan, Mohanalaxmi; Misharin, Alexander V.; Greaves, David R. et al. (2017-06-05). "The PYRIN domain-only protein POP2 inhibits inflammasome priming and activation". Nature Communications 8 (1): 15556. doi:10.1038/ncomms15556. ISSN 2041-1723. PMID 28580931. PMC PMC5465353. https://www.nature.com/articles/ncomms15556. 
  35. Youm, Yun-Hee; Nguyen, Kim Y.; Grant, Ryan W.; Goldberg, Emily L.; Bodogai, Monica; Kim, Dongin; D'Agostino, Dominic; Planavsky, Noah et al. (2015-03). "The ketone metabolite β-hydroxybutyrate blocks NLRP3 inflammasome–mediated inflammatory disease". Nature Medicine 21 (3): 263–269. doi:10.1038/nm.3804. ISSN 1546-170X. PMID 25686106. PMC PMC4352123. https://www.nature.com/articles/nm.3804. 
  36. Shim, Do-Wan; Lee, Kwang-Ho (2018). "Posttranslational Regulation of the NLR Family Pyrin Domain-Containing 3 Inflammasome". Frontiers in Immunology 9. doi:10.3389/fimmu.2018.01054. ISSN 1664-3224. PMID 29868015. PMC PMC5968104. https://www.frontiersin.org/articles/10.3389/fimmu.2018.01054. 
  37. Zhang, Zhirong; Meszaros, Gergö; He, Wan-ting; Xu, Yanfang; de Fatima Magliarelli, Helena; Mailly, Laurent; Mihlan, Michael; Liu, Yansheng et al. (2017-07-17). "Protein kinase D at the Golgi controls NLRP3 inflammasome activation". Journal of Experimental Medicine 214 (9): 2671–2693. doi:10.1084/jem.20162040. ISSN 0022-1007. PMID 28716882. PMC PMC5584123. https://doi.org/10.1084/jem.20162040. 
  38. Guo, Chuansheng; Xie, Shujun; Chi, Zhexu; Zhang, Jinhua; Liu, Yangyang; Zhang, Li; Zheng, Mingzhu; Zhang, Xue et al. (2016-10-18). "Bile Acids Control Inflammation and Metabolic Disorder through Inhibition of NLRP3 Inflammasome". Immunity 45 (4): 802–816. doi:10.1016/j.immuni.2016.09.008. ISSN 1074-7613. PMID 27692610. https://www.cell.com/immunity/abstract/S1074-7613(16)30352-1. 
  39. Py, Bénédicte F.; Kim, Mi-Sung; Vakifahmetoglu-Norberg, Helin; Yuan, Junying (2013-01-24). "Deubiquitination of NLRP3 by BRCC3 Critically Regulates Inflammasome Activity". Molecular Cell 49 (2): 331–338. doi:10.1016/j.molcel.2012.11.009. ISSN 1097-2765. PMID 23246432. https://www.cell.com/molecular-cell/abstract/S1097-2765(12)00940-9. 
  40. Ren, Guangming; Zhang, Xuanyi; Xiao, Yang; Zhang, Wen; Wang, Yu; Ma, Wenbing; Wang, Xiaohan; Song, Pan et al. (2019-03-15). "ABRO1 promotes NLRP3 inflammasome activation through regulation of NLRP3 deubiquitination". The EMBO Journal 38 (6). doi:10.15252/embj.2018100376. ISSN 0261-4189. PMID 30787184. PMC PMC6418445. https://onlinelibrary.wiley.com/doi/10.15252/embj.2018100376. 
  41. Lei-Leston, Andrea C.; Murphy, Alison G.; Maloy, Kevin J. (2017). "Epithelial Cell Inflammasomes in Intestinal Immunity and Inflammation". Frontiers in Immunology 8. doi:10.3389/fimmu.2017.01168. ISSN 1664-3224. PMID 28979266. PMC PMC5611393. https://www.frontiersin.org/articles/10.3389/fimmu.2017.01168. 
  42. Zhao, Chunyuan; Zhao, Wei (2020). "NLRP3 Inflammasome—A Key Player in Antiviral Responses". Frontiers in Immunology 11. doi:10.3389/fimmu.2020.00211. ISSN 1664-3224. PMID 32133002. PMC PMC7040071. https://www.frontiersin.org/articles/10.3389/fimmu.2020.00211. 
  43. Elinav, Eran; Strowig, Till; Kau, Andrew L.; Henao-Mejia, Jorge; Thaiss, Christoph A.; Booth, Carmen J.; Peaper, David R.; Bertin, John et al. (2011-05-27). "NLRP6 Inflammasome Regulates Colonic Microbial Ecology and Risk for Colitis". Cell 145 (5): 745–757. doi:10.1016/j.cell.2011.04.022. ISSN 0092-8674. PMID 21565393. PMC PMC3140910. https://www.cell.com/cell/abstract/S0092-8674(11)00480-6. 
  44. Mamantopoulos, Michail; Ronchi, Francesca; Hauwermeiren, Filip Van; Vieira-Silva, Sara; Yilmaz, Bahtiyar; Martens, Liesbet; Saeys, Yvan; Drexler, Stefan K. et al. (2017-08-15). "Nlrp6- and ASC-Dependent Inflammasomes Do Not Shape the Commensal Gut Microbiota Composition". Immunity 47 (2): 339–348.e4. doi:10.1016/j.immuni.2017.07.011. ISSN 1074-7613. PMID 28801232. https://www.cell.com/immunity/abstract/S1074-7613(17)30318-7. 
  45. He, Wan-ting; Wan, Haoqiang; Hu, Lichen; Chen, Pengda; Wang, Xin; Huang, Zhe; Yang, Zhang-Hua; Zhong, Chuan-Qi et al. (2015-12). "Gasdermin D is an executor of pyroptosis and required for interleukin-1β secretion". Cell Research 25 (12): 1285–1298. doi:10.1038/cr.2015.139. ISSN 1748-7838. PMID 26611636. PMC PMC4670995. https://www.nature.com/articles/cr2015139. 
  46. Karmakar, Mausita; Minns, Martin; Greenberg, Elyse N.; Diaz-Aponte, Jose; Pestonjamasp, Kersi; Johnson, Jennifer L.; Rathkey, Joseph K.; Abbott, Derek W. et al. (2020-05-05). "N-GSDMD trafficking to neutrophil organelles facilitates IL-1β release independently of plasma membrane pores and pyroptosis". Nature Communications 11 (1): 2212. doi:10.1038/s41467-020-16043-9. ISSN 2041-1723. PMID 32371889. PMC PMC7200749. https://www.nature.com/articles/s41467-020-16043-9. 
  47. Shi, Jianjin; Zhao, Yue; Wang, Kun; Shi, Xuyan; Wang, Yue; Huang, Huanwei; Zhuang, Yinghua; Cai, Tao et al. (2015-10). "Cleavage of GSDMD by inflammatory caspases determines pyroptotic cell death". Nature 526 (7575): 660–665. doi:10.1038/nature15514. ISSN 1476-4687. https://www.nature.com/articles/nature15514. 
  48. Kastner, Daniel L.; Aksentijevich, Ivona; Goldbach-Mansky, Raphaela (2010-03-19). "Autoinflammatory Disease Reloaded: A Clinical Perspective". Cell 140 (6): 784–790. doi:10.1016/j.cell.2010.03.002. ISSN 0092-8674. PMID 20303869. PMC PMC3541025. https://www.cell.com/cell/abstract/S0092-8674(10)00238-2. 
  49. Feldmann, Jérôme; Prieur, Anne-Marie; Quartier, Pierre; Berquin, Patrick; Certain, Stéphanie; Cortis, Elisabetta; Teillac-Hamel, Dominique; Fischer, Alain et al. (2002-07-01). "Chronic Infantile Neurological Cutaneous and Articular Syndrome Is Caused by Mutations in CIAS1, a Gene Highly Expressed in Polymorphonuclear Cells and Chondrocytes". The American Journal of Human Genetics 71 (1): 198–203. doi:10.1086/341357. ISSN 0002-9297. PMID 12032915. PMC PMC384980. https://www.cell.com/ajhg/abstract/S0002-9297(07)60051-2. 
  50. Jesus, Adriana A.; Goldbach-Mansky, Raphaela (2014-01-14). "IL-1 Blockade in Autoinflammatory Syndromes". Annual Review of Medicine 65 (1): 223–244. doi:10.1146/annurev-med-061512-150641. ISSN 0066-4219. PMID 24422572. PMC PMC4178953. https://www.annualreviews.org/doi/10.1146/annurev-med-061512-150641. 
  51. 51.0 51.1 Kingsbury, Sarah R.; Conaghan, Philip G.; McDermott, Michael F. (2011-03-13). "The role of the NLRP3 inflammasome in gout". Journal of Inflammation Research 4: 39–49. doi:10.2147/JIR.S11330. PMID 22096368. PMC PMC3218743. https://www.dovepress.com/the-role-of-the-nlrp3-inflammasome-in-gout-peer-reviewed-fulltext-article-JIR. 
  52. Martinon, Fabio; Pétrilli, Virginie; Mayor, Annick; Tardivel, Aubry; Tschopp, Jürg (2006-03). "Gout-associated uric acid crystals activate the NALP3 inflammasome". Nature 440 (7081): 237–241. doi:10.1038/nature04516. ISSN 1476-4687. https://www.nature.com/articles/nature04516. 
  53. Liu-Bryan, Ru; Scott, Peter; Sydlaske, Anya; Rose, David M.; Terkeltaub, Robert (2005-09). "Innate immunity conferred by toll-like receptors 2 and 4 and myeloid differentiation factor 88 expression is pivotal to monosodium urate monohydrate crystal-induced inflammation". Arthritis & Rheumatism 52 (9): 2936–2946. doi:10.1002/art.21238. ISSN 0004-3591. https://onlinelibrary.wiley.com/doi/10.1002/art.21238. 
  54. Guma, Monica; Ronacher, Lisa; Liu-Bryan, Ru; Takai, Shinji; Karin, Michael; Corr, Maripat (2009-12). "Caspase 1–independent activation of interleukin-1β in neutrophil-predominant inflammation". Arthritis & Rheumatism 60 (12): 3642–3650. doi:10.1002/art.24959. PMID 19950258. PMC PMC2847793. https://onlinelibrary.wiley.com/doi/10.1002/art.24959. 
  55. Joosten, Leo A. B.; Netea, Mihai G.; Fantuzzi, Giamila; Koenders, Marije I.; Helsen, Monique M. A.; Sparrer, Helmut; Pham, Christine T.; van der Meer, Jos W. M. et al. (2009-12). "Inflammatory arthritis in caspase 1 gene–deficient mice: Contribution of proteinase 3 to caspase 1–independent production of bioactive interleukin-1β". Arthritis & Rheumatism 60 (12): 3651–3662. doi:10.1002/art.25006. PMID 19950280. PMC PMC2993325. https://onlinelibrary.wiley.com/doi/10.1002/art.25006. 
  56. Zahid, Ayesha; Li, Bofeng; Kombe, Arnaud John Kombe; Jin, Tengchuan; Tao, Jinhui (2019). "Pharmacological Inhibitors of the NLRP3 Inflammasome". Frontiers in Immunology 10. doi:10.3389/fimmu.2019.02538. ISSN 1664-3224. PMID 31749805. PMC PMC6842943. https://www.frontiersin.org/articles/10.3389/fimmu.2019.02538. 
  57. Marchetti, Carlo; Swartzwelter, Benjamin; Gamboni, Fabia; Neff, Charles P.; Richter, Katrin; Azam, Tania; Carta, Sonia; Tengesdal, Isak et al. (2018-02-13). "OLT1177, a β-sulfonyl nitrile compound, safe in humans, inhibits the NLRP3 inflammasome and reverses the metabolic cost of inflammation". Proceedings of the National Academy of Sciences 115 (7). doi:10.1073/pnas.1716095115. ISSN 0027-8424. PMID 29378952. PMC PMC5816172. https://pnas.org/doi/full/10.1073/pnas.1716095115. 
  58. Klück, Viola; Jansen, Tim L. Th A.; Janssen, Matthijs; Comarniceanu, Antoaneta; Efdé, Monique; Tengesdal, Isak W.; Schraa, Kiki; Cleophas, Maartje C. P. et al. (2020-05-01). "Dapansutrile, an oral selective NLRP3 inflammasome inhibitor, for treatment of gout flares: an open-label, dose-adaptive, proof-of-concept, phase 2a trial". The Lancet Rheumatology 2 (5): e270–e280. doi:10.1016/S2665-9913(20)30065-5. ISSN 2665-9913. PMID 33005902. PMC PMC7523621. https://www.thelancet.com/journals/lanrhe/article/PIIS2665-9913(20)30065-5/abstract.