Natural cytotoxicity triggering receptor 2 is a protein that in humans is encoded by the NCR2 gene. [3] [4] NCR2 has also been designated as CD336 (cluster of differentiation 336), NKp44, NKP44; NK-p44, LY95, and dJ149M18.1. [5]
Natural cytotoxicity triggering receptor 2 is a protein that in humans is encoded by the NCR2 gene. [3] [4] NCR2 has also been designated as CD336 (cluster of differentiation 336), NKp44, NKP44; NK-p44, LY95, and dJ149M18.1. [5]
Natural killer cells, also known as NK cells or large granular lymphocytes (LGL), are a type of cytotoxic lymphocyte critical to the innate immune system that belong to the rapidly expanding family of innate lymphoid cells (ILC) and represent 5–20% of all circulating lymphocytes in humans. The role of NK cells is analogous to that of cytotoxic T cells in the vertebrate adaptive immune response. NK cells provide rapid responses to virus-infected cell and other intracellular pathogens acting at around 3 days after infection, and respond to tumor formation. Typically, immune cells detect the major histocompatibility complex (MHC) presented on infected cell surfaces, triggering cytokine release, causing the death of the infected cell by lysis or apoptosis. NK cells are unique, however, as they have the ability to recognize and kill stressed cells in the absence of antibodies and MHC, allowing for a much faster immune reaction. They were named "natural killers" because of the notion that they do not require activation to kill cells that are missing "self" markers of MHC class 1. This role is especially important because harmful cells that are missing MHC I markers cannot be detected and destroyed by other immune cells, such as T lymphocyte cells.
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. At least 15 genes and 2 pseudogenes encoding KIR map in a 150-kb region of the leukocyte receptor complex (LRC) on human chromosome 19q13.4 They regulate the killing function of these cells by interacting with major histocompatibility (MHC) class I molecules, which are expressed on all nucleated cell types. KIR receptors can distinguish between major histocompatibility (MHC) class I allelic variants, which allows them to detect virally infected cells or transformed cells. KIRs are paired receptors with both activating and inhibitory functions; most KIRs are inhibitory, meaning that their recognition of MHC molecules suppresses the cytotoxic activity of their NK cell. Only a limited number of KIRs are activating, meaning that their recognition of MHC molecules activates the cytotoxic activity of their cell. Initial expression of KIRs on NK cells is stochastic, but there is an educational process that NK cells undergo as they mature that alters the expression of KIRs to maximize the balance between effective defense and self-tolerance. As a result of KIR's role in killing unhealthy self-cells and not killing healthy self-cells, KIRs are involved in protection against and propensity to viral infection, autoimmune disease, and cancer. KIR molecules are highly polymorphic, meaning that their gene sequences differ greatly between individuals, and polygenic so that it is extremely rare for two unrelated individuals to possess the same KIR genotype.
TYRO protein tyrosine kinase-binding protein is an adapter protein that in humans is encoded by the TYROBP gene.
CD244 is a human protein encoded by the CD244 gene. It is also known as Natural Killer Cell Receptor 2B4
Killer cell immunoglobulin-like receptor 3DL1 is a protein that in humans is encoded by the KIR3DL1 gene.
Killer cell immunoglobulin-like receptor 2DL4 is a protein that in humans is encoded by the KIR2DL4 gene.
Natural cytotoxicity triggering receptor 3 is a protein that in humans is encoded by the NCR3 gene. NCR3 has also been designated as CD337 and as NKp30. NCR3 belongs to the family of NCR membrane receptors together with NCR1 (NKp46) and NCR2 (NKp44).
NKG2-F type II integral membrane protein is a protein that in humans is encoded by the KLRC4 gene.
Natural cytotoxicity triggering receptor 1 is a protein that in humans is encoded by the NCR1 gene. NCR1 has also been designated as CD335 (cluster of differentiation, NKP46, NKp46, NK-p46, and LY94.
Killer cell immunoglobulin-like receptor 3DL2 is a protein that in humans is encoded by the KIR3DL2 gene.
CD226, PTA1 or DNAM-1 is a protein that in humans is encoded by the CD226 gene which is located on chromosome 18q22.3.
Killer cell lectin-like receptor subfamily B, member 1, also known as KLRB1, NKR-P1A or CD161, is a human gene.
Leukocyte-specific transcript 1 protein is a protein that in humans is encoded by the LST1 gene.
SLAM family member 6 is a protein that in humans is encoded by the SLAMF6 gene.
Killer cell immunoglobulin-like receptor 2DS4 is a protein that in humans is encoded by the KIR2DS4 gene.
Interleukin 21 receptor is a type I cytokine receptor. IL21R is its human gene.
Hematopoietic cell signal transducer is a protein that in humans is encoded by the HCST gene.
CD160 antigen is a protein that in humans is encoded by the CD160 gene.
CD300A is a human gene.
Killer Activation Receptors (KARs) are receptors expressed on the plasmatic membrane of Natural Killer cells. KARs work together with inhibitory receptors, which inactivate them in order to regulate the NK cells functions on hosted or transformed cells. These two kinds of specific receptors have some morphological features in common, such as being transmembrane proteins. The similarities are specially found in the extracellular domains and, the differences tend to be in the intracellular domains. KARs and KIRs can have tyrosine containing activatory or inhibitory motifs in the intracellular part of the receptor molecule.
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