The Human Reactive Inflammasome Antibody Sampler Kit II provides an economical means of detecting multiple inflammasome components. The kit contains enough primary antibodies to perform at least two western blot experiments.
Specificity / Sensitivity
Each antibody in the Human Reactive Inflammasome Antibody Sampler Kit II detects endogenous levels of its target protein. AIM2 (D5X7K) Rabbit mAb detects a 22 kDa band of unknown origin in some cell lines. Caspase-1 (D7F10) Rabbit mAb detects endogenous levels of full-length human Caspase-1; the activated p20 subunit was detected by overexpression. ASC/TMS1 (E1E3I) Rabbit mAb can detect three known isoforms of ASC/TMS1. Cleaved Caspase-1 (Asp297) (D57A2) Rabbit mAb detects endogenous levels of the p20 subunit of human caspase-1 only upon cleavage at Asp297. Cleaved-IL-1β (Asp116) (D3A3Z) Rabbit mAb recognizes endogenous levels of mature IL-1β protein only when cleaved at Asp116. IL-1β (D3U3E) Rabbit mAb is not able to detect endogenous levels of mature IL-1β. It can detect up to 100 pg of recombinant mature IL-1β.
Source / Purification
Monoclonal antibodies are produced by immunizing animals with recombinant human IL-1β protein or with synthetic peptides corresponding to residues adjacent to Asp297 human caspase-1, residues adjacent to Asp116 of human IL-1β, residues surrounding Ala306 of mouse NLRP3, Lys93 of human AIM2, Leu942 of human NLRC4, and the carboxy terminus of human ASC/TMS1 isoform 1.
The innate immune system works as the first line of defense in protection from pathogenic microbes and host-derived signals of cellular distress. One way in which these “danger” signals trigger inflammation is through activation of inflammasomes, which are multiprotein complexes that assemble in the cytosol after exposure to pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs) and result in the activation of caspase-1 and subsequent cleavage of proinflammatory cytokines IL-1β and IL-18 (Reviewed in 1-6). Inflammasome complexes typically consist of a cytosolic pattern recognition receptor (PRR; a nucleotide-binding domain and leucine-rich-repeat [NLR] or AIM2-like receptor [ALR] family member), an adaptor protein (ASC/TMS1), and pro-caspase-1. A number of distinct inflammasome complexes have been identified, each with a unique PRR and activation triggers. The best characterized is the NLRP3 complex, which contains NLRP3, ASC/TMS1, and pro-caspase-1. The NLRP3 inflammasome is activated in a two-step process. First, NF-κB signaling is induced through PAMP- or DAMP-mediated activation of TLR4 or TNFR, resulting in increased expression of NLRP3, pro-IL-1β, and pro-IL-18 (priming step, signal 1). Next, indirect activation of NLRP3 occurs by a multitude of signals (whole pathogens, PAMPs/DAMPs, potassium efflux, lysosomal-damaging environmental factors [uric acid, silica, alum] and endogenous factors [amyloid-β, cholesterol crystals], and mitochondrial damage), leading to complex assembly and activation of caspase-1 (signal 2). The complex inflammasome structure is built via domain interactions among the protein components. Other inflammasomes are activated by more direct means: double-stranded DNA activates the AIM2 complex, anthrax toxin activates NLRP1, and bacterial flagellin activates NLRC4. Activated caspase-1 induces secretion of proinflammatory cytokines IL-1β and -18, but also regulates metabolic enzyme expression, phagosome maturation, vasodilation, and pyroptosis, an inflammatory programmed cell death. Inflammasome signaling contributes to the onset of a number of diseases, including atherosclerosis, type II diabetes, Alzheimer’s disease, and autoimmune disorders.