Monoclonal Antibody to mouse NALP3/NLRP3 (NOD Domain)

Background
NALP3/NLRP3 belongs to the NLR family of innate immune cytoplasmic receptors (reviewed in De Nardo and Latz, 2011; Kanneganti, 2010; Anand, 2011). NLR family members contain an N-terminus effector region consisting of either a pyrin (PYD), a CARD, or a BIR domain. NLRs also have an intermediate conserved NOD domain and a C-terminus LRR domain. NLRs, like TLRs, alert the immune system to the presence of PAMPs and DAMPs.  Like a number of other NLRs, NLRP3 functions in a multiprotein complex called the inflammasome. The inclusion of a particular NLR within an inflammasome depends upon the upstream trigger. The NLRP3 inflammasome is considered to be a global sensor and assembles in response to a broad spectrum of PAMPs and DAMPs. For example, helmith, bacteria, plasmodium and viruses have all been shown to activate NLRP3 (reviewed in Menu and Vince, 2011). The PYD of activated NLRP3 associates with the PYD of ASC, triggering the CARD of ASC to associate with the CARD of caspase-1 and completes the assembly of the NLRP3 inflammasome. This serves as a platform for caspase-1 activation.

Activation of NLRP3 can be inhibited by glybenclamide (also known as glyburide) (reviewed in Lamkanfi et al, 2009). Glybenclamide is an ATP-sensitive potassion channel inhibitor that has been shown to inhibit various biological processes including activation of the NRLP3 inflammasome. Glybenclamide is thought to act downstream of the P2X7 receptor but upsteam of NLRP3. Glybenclamide blocks activation of caspase-1 and IL-1beta K+ efflux inhibition. Glybenclamide has a number of additional functions besides blocking including enhancing insulin action and stimulating synthesis of glucose transporters. Researchers are encouraged to consult the published literature regarding additional information about how glybenclamide perturbs biological processes.

Antigen
A recombinant protein corresponding to the NOD domain* of murine NALP3/NLRP3 (amino acids 216-385) was used as the immunogen for this antibody. *Each region of NALP3 has a different function. Oligomerization of NOD is required for formation of the NLRP3 inflammasome. The epitope that IMG25N10E9 binds to in the NOD region has not been mapped.

Application Notes
The specificity of the antibody has been validated with a mouse NALP3 transfected cell lysate (lane A) and recombinant mouse NALP3 protein fragment (lane D) as shown in the western blot image. Additional NALP3/NLRP3 antibodies and products can be found here.

Reference
1. Lamkanfi M, AC Vitari, S Misaghi, A Fedorova, K Deshayes, WP Lee, HM Hoffman, VM Dixit . Glyburid inhibits the cryopyrin/Nalp3 inflammasome.  JCB 187:61-70 (2009).
2. Menu P; Vince JE. The NLRP3 inflamasome in health and disease: the good, the bad and the ugly. Clinical & Experimental Immunol DOI:10.1111/j.1365-2249.2011.04440.x
3. Anand PK, K S Malireddi, T-D Kanneganti. Role of the Nlrp3 inflammasome in microbial infection. Frontiers Microbiol doi: 10.3389/fmicb.2011.0012 (2011). 
4. Kanneganti T-D. Central roles of NLRs and inflammasomes in viral infection. Nature Rev Immunol 10:689-698 (2010).  
5. De Nardo D and E Latz. NLRP3 inflammasomes link inflammation and metabolic disease. Trends Immunol 32:373-379 (2011).