Synergistic Activation of Toll-Like and NOD Receptors by Complementary Antigens as Facilitators of Autoimmune Disease: Review, Model and Novel Predictions

Int J Mol Sci. 2020 Jun 30;21(13):4645. doi: 10.3390/ijms21134645.

Abstract

Persistent activation of toll-like receptors (TLR) and nucleotide-binding oligomerization domain-containing proteins (NOD) in the innate immune system is one necessary driver of autoimmune disease (AD), but its mechanism remains obscure. This study compares and contrasts TLR and NOD activation profiles for four AD (autoimmune myocarditis, myasthenia gravis, multiple sclerosis and rheumatoid arthritis) and their animal models. The failure of current AD theories to explain the disparate TLR/NOD profiles in AD is reviewed and a novel model is presented that explains innate immune support of persistent chronic inflammation in terms of unique combinations of complementary AD-specific antigens stimulating synergistic TLRs and/or NODs. The potential explanatory power of the model is explored through testable, novel predictions concerning TLR- and NOD-related AD animal models and therapies.

Keywords: NOD; TLR; Toll-like receptors; anti-idiotype; antigenic complementarity; autoimmunity; bystander activation; complementary antigens; innate immunity; molecular mimicry; nucleotide-binding oligomerization domain-containing proteins; synergy; theory.

Publication types

  • Review

MeSH terms

  • Animals
  • Antigens
  • Autoimmune Diseases / immunology*
  • Autoimmune Diseases / physiopathology
  • Disease Models, Animal
  • Humans
  • Immunity, Innate / immunology
  • Nod Signaling Adaptor Proteins / metabolism
  • Nod2 Signaling Adaptor Protein / immunology
  • Nod2 Signaling Adaptor Protein / metabolism*
  • Signal Transduction
  • Toll-Like Receptors / immunology
  • Toll-Like Receptors / metabolism*

Substances

  • Antigens
  • Nod Signaling Adaptor Proteins
  • Nod2 Signaling Adaptor Protein
  • Toll-Like Receptors