Examining host–microbial interactions through the lens of NOD: From plants to mammals

Nod-like receptors (NLRs) for detecting microbial invaders are features of many plant and animal families. Although broadly similar in form and function, intimate co-evolutionary events with environmental microbes have shaped specific classes of NLRs in different types of hosts. Details of the roles of different NLRs in signaling cellular immune responses to invading microbes are only beginning to emerge. This review will discuss the current understanding of NLRs in plants, invertebrates, and mammals, with emphasis on their role in regulating NF-κB and inflammasome activity in mammals.

► Intracellular receptors (NLRs) detect microbial invaders in plant and animal cells.
► Plant R proteins detect pathogen effectors indirectly by monitoring “modified self”.
► NLRs are found in deuterostomes and more ancient invertebrate families.
► Mammalian NLRs, Nod1 and Nod2, directly activate the NF-κB signaling pathway.
► Mammalian NLRs detect flagellin and type III secretion to activate the inflammasome.