with other proteins (e.g. the adaptor molecule ASC) is mediated via N-terminal pyrin (PYD) domain. There are 14 members of this protein subfamily in humans (called NLRP1 to NLRP14). NLRP3 and NLRP4 are responsible for the inflammasome activation. NLRP3 can be activated and give rise to NLRP3 inflammasome by ATP, bacterial pore-forming toxins, alum and crystals. Alongside the listed molecules, which lead to activation of NLRP3 inflammasome, the assembly and activation can also be induced by K+ efflux, Ca2+ influx, disruption of lysosomes and ROS originating from mitochondria. The NLRP3 inflammasome is essential for induction of effective immune response. The NLRP3 inflammasome can be induced by a wide range of stimuli in contrast to the NLRP4 inflammasome, which binds more limited number and variety of ligands and works in a complex with NAIP protein. Other NLRs such as IPAF and NAIP5/Birc1e have also been shown to activate caspase-1 in response to Salmonella and Legionella. NLR signaling Some of these proteins recognize endogenous or microbial molecules or stress responses and form oligomers that, in animals, activate inflammatory caspases (e.g. caspase 1) causing cleavage and activation of important inflammatory cytokines such as IL-1, and/or activate the NF-κB signaling pathway to induce production of inflammatory molecules. The NLR family is known under several different names, including the CATERPILLER (or CLR) or NOD-LRR family. The most significant members of the NLRs are NOD1 and NOD2. They sense the conserved microbial peptidoglycans in the cytoplasm of the cell and therefore represent another level of immune response after membrane-bound receptors such as TLRs and CLRs. This family of proteins is greatly expanded in plants, and constitutes a core component of plant immune systems. RIG-I-like receptors (RLR) Three RLR helicases have so far been described: RIG-I and MDA5 (recognizing 5'triphosphate-RNA and dsRNA, respectively), which activate antiviral signaling, and LGP2, which appears to act as a dominant-negative inhibitor. RLRs initiate the release of inflammatory cytokines and type I interferon (IFN I). RLR signaling RLRs are RNA helicases, which have been shown to participate in intracellular recognition of viral double-stranded (ds) and single stranded RNA which recruit factors via twin N-terminal CARD domains to activate antiviral gene programs, which may be exploited in therapy of viral infections. It has been suggested that the main antiviral program induced by RLR is based on ATPase activity. RLRs often interact and create cross-talk with the TLRs in the innate immune response and