The innate immune system relies on a vast array of non-clonally expressed pattern recognition receptors for the detection of pathogens
- These are a class of proteins that play a key role in the innate immune system which is the primary response and consists of opsonization, activation of complement and coagulation cascades, phagocytosis, activation of pro-inflammatory signalling cascades, and apoptosis.
- They are single, membrane-spanning, non-catalytic receptors usually expressed on sentinel cells such as macrophages and dendritic cells, that recognize structurally conserved molecules derived from microbes. Pattern recognition receptors bind conserved molecular structures found in large groups of pathogens, termed pathogen-associated molecular patterns
- NOD-like receptors are intracellular pattern recognition receptors that activate downstream signalling cascades leading to activation of components of the inflammasome
- Toll-like receptors (TLRs) are being implicated in the pathology of rheumatoid arthritis, ankylosing spondylitis, Lyme arthritis and osteoarthritis. At least 10 forms of TLRs exist.
- C-type lectin receptors (CLR)