NLRP8

NLRPs (acronym for "NIGHT, LRR and PYD domains-containing protein) are, together with the NOD1 and NOD2 proteins, members of the NLR (Nod-like Receptor) protein family and play a major role in innate immunity as pathogen recognition receptors (PPRs). Like the NOD proteins, NLRPs are expressed exclusively cytoplasmically. All NLRPs (they all contain a pyrin domain) are encoded by a common gene family in humans. NLRPs are characterised by their ability to activate different inflammatory complexes.

NLRP8 is a cytosolic protein encoded in humans by the NLRP8 gene located on chromosome 19: q13.43 within a cluster of other NLRP genes.

Inflammasomes are differently composed cytosolic protein complexes, whereby the different NLRPs are of great importance for their functionality. Inflammasomes are predominantly found in immune cells such as dendritic cells and macrophages.

The activation of an inflammasome complex leads to the expression of different caspases, which convert inactive interleukin-1beta and interleukin-18 into their active form.

Little is known about the mode of action of NLRP8. NLRP8 and NLRP9 are expressed in tests and ovaries. Monocytes are also capable of expressing NLRP8. Thus, functions in certain infections are known. Toxoplasma gondii infected macrophages react to this pathogen by upregulating pathogen recognition receptors such as NLRP8, NLRP1, NLRP3, NLRC4, NLRP6, NLRP13, AIM2 and NAIP. This leads to an activation of inflammasomes.

1. Chu JQ et al (2016) Production of IL-1β and Inflammasome with Up-Regulated Expressions of NOD-Like Receptor Related Genes in Toxoplasma gondii-Infected THP-1 Macrophages. Korean J Parasitol 54(:711-717.

2. Ponsuksili S et al (2006) Bovine NALP5, NALP8, and NALP9 genes: assignment to a QTL region and the expression in adult tissues, oocytes, and preimplantation embryos. Biol Reprod 74:577-584.