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Leukocyte Receptor Complex
The leukocyte immunoglobulin-like receptors (LILR) are a family of receptors possessing extracellular immunoglobulin domains. 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 at chromosomal region 19q13.4. They include * LILRA1 * LILRA2 * LILRA3 * LILRA4 * LILRA5 * LILRA6 * LILRB1 * LILRB2 * LILRB3 * LILRB4 * LILRB5 * LILRB6 or LILRA6 * LILRB7 or LILRA5 A subset of LILR recognise MHC class I (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 show a broad specificity f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Family
A protein family is a group of evolutionarily related proteins. In many cases, a protein family has a corresponding gene family, in which each gene encodes a corresponding protein with a 1:1 relationship. The term "protein family" should not be confused with family as it is used in taxonomy. Proteins in a family descend from a common ancestor and typically have similar three-dimensional structures, functions, and significant sequence similarity. The most important of these is sequence similarity (usually amino-acid sequence), since it is the strictest indicator of homology and therefore the clearest indicator of common ancestry. A fairly well developed framework exists for evaluating the significance of similarity between a group of sequences using sequence alignment methods. Proteins that do not share a common ancestor are very unlikely to show statistically significant sequence similarity, making sequence alignment a powerful tool for identifying the members of protein famil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 chromosomal region 19q13.4. The encoded protein belongs to the subfamily B class of LIR receptors which contain two or four extracellular immunoglobulin domains, a transmembrane domain, and two to four cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs). The receptor is expressed on immune cells where it binds to MHC class I molecules on antigen-presenting cells and transduces a negative signal that inhibits stimulation of an immune response. It is thought to control inflammatory responses and cytotoxicity to help focus the immune response and limit autoreactivity. Multiple transcript variants encoding different isoforms have been found for this gene. LILBR2 plays a critical role in the inhibition of axonal regeneration and fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 inhibitory receptor found on peripheral mononuclear cells, including NK cells, T cells, and B cells. Inhibitory receptors regulate the immune response to prevent lysis of cells recognized as self. The gene is a member of both the immunoglobulin superfamily and the leukocyte-associated inhibitory receptor family. The gene maps to a region of 19q13.4 called the leukocyte receptor cluster, which contains at least 29 genes encoding leukocyte-expressed receptors of the immunoglobulin superfamily. Interactions LAIR1 has been shown to interact with PTPN11 and PTPN6 Tyrosine-protein phosphatase non-receptor type 6, also known as Src homology region 2 domain-containing phosphatase-1 (SHP-1), is an enzyme that in humans is encoded by the ''PTPN6'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HLA-C
HLA-C belongs to the MHC (human = HLA) 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 molecules, like HLA-C, are expressed in nearly all cells, and present small peptides to the immune system which surveys for non-self peptides. HLA-C is a locus on chromosome 6, which encodes for many HLA-C alleles that are Class-I MHC receptors. HLA-C, localized proximal to the HLA-B locus, is located on the distal end of the HLA region. Most HLA-C:B haplotypes are in strong linkage disequilibrium and many are as ancient as the human species itself. Disease associations By serotype Cw1: multinodular goiters By allele C*16: B-cell chronic lymphocytic leukemia Nomenclature C*01 *Cw1 serotype: C*01:02 and C*01:09 *Cw11 *C*01:04 to *01:08 C*02 *Cw2 serotype: C*02:02 and *02:08 *C*02:03 to *02:07, and 02:09 C*03 *Cw9 serotype: C*03:03 *Cw10 ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta-2 Microglobulin
β2 microglobulin (B2M) is a component of MHC class I molecules. MHC class I molecules have α1, α2, and α3 proteins which are present on all nucleated cells (excluding red blood cells). In humans, the β2 microglobulin protein is encoded by the ''B2M'' gene. Structure and function β2 microglobulin lies beside the α3 chain on the cell surface. Unlike α3, β2 has no transmembrane region. Directly above β2 (that is, further away from the cell) lies the α1 chain, which itself is next to the α2. β2 microglobulin associates not only with the alpha chain of MHC class I molecules, but also with class I-like molecules such as CD1 (5 genes in humans), MR1, the neonatal Fc receptor (FcRn), and Qa-1 (a form of alloantigen). Nevertheless, the β2 microglobulin gene is outside of the MHC (HLA) locus, on a different chromosome. An additional function is association with the HFE protein, together regulating the expression of hepcidin in the liver which targets the iron transporte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paired Receptors
Paired receptors are pairs or clusters of receptor proteins that bind to extracellular ligands but have opposing activating and inhibitory signaling effects. Traditionally, paired receptors are defined as homologous pairs with similar extracellular domains and different cytoplasmic regions, whose genes are located together in the genome as part of the same gene cluster and which evolved through gene duplication. Homologous paired receptors often, but not always, have a shared ligand in common. More broadly, pairs of receptors have been identified that exhibit paired functional behavior - responding to a shared ligand with opposing intracellular signals - but are not closely homologous or co-located in the genome. Paired receptors are highly expressed in the cells of the immune system, especially natural killer (NK) and myeloid cells, and are involved in immune regulation. Structure Paired receptors are membrane proteins with extracellular domains that interact with extracell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Leukocyte Antigen
The human leukocyte antigen (HLA) system or complex is a complex of genes on chromosome 6 in humans which encode cell-surface proteins responsible for the regulation of the immune system. The HLA system is also known as the human version of the major histocompatibility complex (MHC) found in many animals. Mutations in HLA genes may be linked to autoimmune disease such as type I diabetes, and celiac disease. The HLA gene complex resides on a 3 Mbp stretch within chromosome 6, p-arm at 21.3. HLA genes are highly polymorphic, which means that they have many different alleles, allowing them to fine-tune the adaptive immune system. The proteins encoded by certain genes are also known as ''antigens'', as a result of their historic discovery as factors in organ transplants. HLAs corresponding to MHC class I ( A, B, and C), all of which are the HLA Class1 group, present peptides from inside the cell. For example, if the cell is infected by a virus, the HLA system brings fra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 platelets, but not on red blood cells. Their function is to display peptide fragments of proteins from within the cell to cytotoxic T cells; this will trigger an immediate response from the immune system against a particular non-self antigen displayed with the help of an MHC class I protein. Because MHC class I molecules present peptides derived from cytosolic proteins, the pathway of MHC class I presentation is often called ''cytosolic'' or ''endogenous pathway''. In humans, the HLAs corresponding to MHC class I are HLA-A, HLA-B, and HLA-C. Function Class I MHC molecules bind peptides generated mainly from degradation of cytosolic proteins by the proteasome. The MHC I:peptide complex is then inserted via endoplasmic reticulum into t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LILRB5
Leukocyte immunoglobulin-like receptor subfamily B member 5 is a protein that in humans is encoded by the ''LILRB5'' gene. This gene is a member of the leukocyte immunoglobulin-like receptor The leukocyte immunoglobulin-like receptors (LILR) are a family of receptors possessing extracellular immunoglobulin domains. They are also known as CD85, ILTs and LIR, and can exert immunomodulatory effects on a wide range of immune cells.Damia ... (LIR) family, which is found in a gene cluster at chromosomal region 19q13.4. The encoded protein belongs to the subfamily B class of LIR receptors which contain two or four extracellular immunoglobulin domains, a transmembrane domain, and two to four cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs). Several other LIR subfamily B receptors are expressed on immune cells where they bind to MHC class I molecules on antigen-presenting cells and inhibit stimulation of an immune response. Multiple transcript variants encoding differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LILRB3
Leukocyte immunoglobulin-like receptor subfamily B member 3 is a protein that in humans is encoded by the ''LILRB3'' gene. This gene is a member of the leukocyte immunoglobulin-like receptor (LIR) family, which is found in a gene cluster at chromosomal region 19q13.4. The encoded protein belongs to the subfamily B class of LIR receptors which contain two or four extracellular immunoglobulin domains, a transmembrane domain, and two to four cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs). The receptor is expressed on immune cells and is believed to be a myeloid checkpoint. It is thought to control inflammatory responses and cytotoxicity to help focus the immune response and limit autoreactivity. Multiple transcript variants encoding different isoforms have been found for this gene. See also * Cluster of differentiation The cluster of differentiation (also known as cluster of designation or classification determinant and often abbreviated as CD) is a protocol us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LILRB1
Leukocyte immunoglobulin-like receptor subfamily B member 1 is a protein that in humans is encoded by the ''LILRB1'' gene. Function This gene is a member of the leukocyte immunoglobulin-like receptor (LIR) family, which is found in a gene cluster at chromosomal region 19q13.4. The encoded protein belongs to the subfamily B class of LIR receptors which contain two or four extracellular immunoglobulin domains, a transmembrane domain, and two to four cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs). The receptor is expressed on immune cells where it binds to MHC class I molecules on antigen-presenting cells and transduces a negative signal that inhibits stimulation of an immune response. It is thought to control inflammatory responses and cytotoxicity to help focus the immune response and limit autoreactivity. Multiple transcript variants encoding different isoforms have been found for this gene. See also * Cluster of differentiation The cluster of differen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
