The polyubiquitin-binding domain of ABIN1 limits TLR-induced MyD88 signaling to prevent spontaneous autoimmunity in mice.

Significance Toll-like receptors recognize conserved molecules that are expressed by both harmless (commensal) and harmful (virulent) microbes. Another set of receptors, nucleotide-binding oligomerization domain-like receptors (NLRs), are expressed in the cytosol and recognize virulence factors and toxins from pathogenic microbes. Previous studies on TLRs and NLRs have suggested that TLR signaling primes the NLR inflammasome pathway. Here we discovered that TLRs, via the signaling molecule IL-1 receptor-associated kinase, directly regulate activation of a specific NLR, nucleotide binding and oligomerization, leucine-rich repeat, pyrin domain-containing 3 (NLRP3). This is important because when infection occurs, the virulent/pathogenic microorganisms activate both of these receptors. We also found that simultaneous activation of TLRs and NLRP3 is important for rapid innate immune response by the host.