About LAIR / Leukocyte-Associated Ig-Like Receptor:
Leukocyte associated immunoglobulin, or more commonly known as LAIR-1 is an immune inhibitory receptor. It is a glycoprotein of 287 amino acids containing a single extracellular C2-type. The genes encoding LAIR-1 are found on the leukocyte receptor on human chromosome 19.
LAIR Structure
Found within immune cells, it has a plethora of ligands found in circulation and tissue. It is an ITIM-bearing collagen receptor expressed by leukocytes hence why it is found on skin immune cells - most often on CD14+ cells. This receptor contains two vital immunoreceptor tyrosine-based motifs. These are better known as ITIMs. It is found within almost all immune cells and commonly found within T cells, B cells as well as monocytes and mast cells and more.
Leukocyte-Associated Ig-Like Receptor Function
When activated they are found within neutrophils. It is known that LAIR is activated during the inflammatory phase of an immune response; such as following a vaccine. With inflammatory conditions, such as sinusitis or asthma, LAIR-1 has an inhibitory function. This means that it inhibits immune cell activation in certain scenarios. LAIR-1 has been studied for many years and it was found in a test on mice, to exacerbate and accelerate an in vivo tumor when overexpressed. It may also be attributed to RCC progression, which is also known as renal cell carcinoma. In autoimmune diseases such as Rheumatoid Arthritis, there are studies that look at ways to suppress T-cell activation by using LAIR-1. It is known that LAIR-1 activation could be used in the control of certain inflammatory and autoimmune diseases. When it meets collagen or C1q, it inhibits TCR signaling.