The leukocyte immunoglobulin-like receptors (LILR) are a
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
of
receptors
Receptor may refer to:
*Sensory receptor, in physiology, any neurite structure that, on receiving environmental stimuli, produces an informative nerve impulse
*Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds ...
possessing extracellular
immunoglobulin domains
The immunoglobulin domain, also known as the immunoglobulin fold, is a type of protein domain that consists of a 2-layer sandwich of 7-9 antiparallel β-strands arranged in two β-sheets with a Greek key topology, consisting of about 125 amino ...
.
They are also known as
CD85, ILTs and LIR, and can exert immunomodulatory effects on a wide range of immune cells.
[Damian Brown, Rachel L Allen, & John Trowsdale. The LILR family: modulators of innate and adaptive immune pathways in health and disease. Tissue Antigens (2004) 64:215 http://onlinelibrary.wiley.com/doi/10.1111/j.0001-2815.2004.00290.x/pdf] The human genes encoding these receptors are found in a
gene cluster
A gene cluster is a group of two or more genes found within an organism's DNA that encode similar peptide, polypeptides or proteins which collectively share a generalized function and are often located within a few thousand base pairs of each othe ...
at chromosomal region 19q13.4.
They include
*
LILRA1
*
LILRA2
*
LILRA3
*
LILRA4
*
LILRA5
*
LILRA6
*
LILRB1
*
LILRB2
Leukocyte immunoglobulin-like receptor subfamily B member 2 is a protein that in humans is encoded by the ''LILRB2'' gene.
This gene is a member of the leukocyte immunoglobulin-like receptor (LIR) family, which is found in a gene cluster at ch ...
*
LILRB3
*
LILRB4
Leukocyte immunoglobulin-like receptor subfamily B member 4 is a protein that in humans is encoded by the ''LILRB4'' gene.
This gene is a member of the leukocyte immunoglobulin-like receptor (LIR) family, which is found in a gene cluster at ch ...
*
LILRB5
* LILRB6 or
LILRA6
* LILRB7 or
LILRA5
A subset of LILR recognise
MHC class I
MHC class I molecules are one of two primary classes of major histocompatibility complex (MHC) molecules (the other being MHC class II) and are found on the cell surface of all nucleated cells in the bodies of vertebrates. They also occur on ...
(also known as
HLA class I in humans). The LILR family is a cluster of
paired receptors with both activating and inhibitory functions.
Of these, the inhibitory receptors
LILRB1 and
LILRB2
Leukocyte immunoglobulin-like receptor subfamily B member 2 is a protein that in humans is encoded by the ''LILRB2'' gene.
This gene is a member of the leukocyte immunoglobulin-like receptor (LIR) family, which is found in a gene cluster at ch ...
show a broad specificity for classical and non-classical MHC alleles with preferential binding to
b2m-associated complexes. In contrast, the activating receptors LILRA1 and
LILRA3 prefer b2m-independent free heavy chains of MHC class I, and in particular
HLA-C
HLA-C (Human Leukocyte Antigen-C) belongs to the MHC class I heavy chain receptors. The C receptor is a heterodimer consisting of a HLA-C mature gene product and β2-microglobulin. The mature C chain is anchored in the membrane. MHC Class I mole ...
alleles.
See also
*
LAIR1
Leukocyte-associated immunoglobulin-like receptor 1 is a protein that in humans is encoded by the ''LAIR1'' gene. LAIR1 has also been designated as CD305 (cluster of differentiation 305).
Function
The protein encoded by this gene is an inhibi ...
*
Killer-cell immunoglobulin-like receptor
Killer-cell immunoglobulin-like receptors (KIRs), are a family of type I transmembrane glycoproteins expressed on the plasma membrane of natural killer (NK) cells and a minority of T cells. In humans, they are encoded in the leukocyte receptor c ...
References
Immunoglobulin superfamily
{{immunology-stub