FCGR3A | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Aliases | FCGR3A , CD16, CD16A, FCG3, FCGR3, FCGRIII, FCR-10, FCRIII, FCRIIIA, IGFR3, IMD20, Fc fragment of IgG receptor IIIa, Fc gamma receptor IIIa, FcGRIIIA, CD16-II | ||||||||||||||||||||||||||||||||||||||||||||||||||
External IDs | OMIM: 146740 MGI: 2179523 HomoloGene: 477 GeneCards: FCGR3A | ||||||||||||||||||||||||||||||||||||||||||||||||||
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Low affinity immunoglobulin gamma Fc region receptor III-A is a protein that in humans is encoded by the FCGR3A gene. [5] [6] It is also known as CD16a as it is part of the cluster of differentiation cell surface molecules.
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 known 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 antigen presented on major histocompatibility complex (MHC) 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 I. 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.
CD32, also known as FcγRII or FCGR2, is a surface receptor glycoprotein belonging to the Ig gene superfamily. CD32 can be found on the surface of a variety of immune cells. CD32 has a low-affinity for the Fc region of IgG antibodies in monomeric form, but high affinity for IgG immune complexes. CD32 has two major functions: cellular response regulation, and the uptake of immune complexes. Cellular responses regulated by CD32 include phagocytosis, cytokine stimulation, and endocytic transport. Dysregulated CD32 is associated with different forms of autoimmunity, including systemic lupus erythematosus. In humans, there are three major CD32 subtypes: CD32A, CD32B, and CD32C. While CD32A and CD32C are involved in activating cellular responses, CD32B is inhibitory.
CD23, also known as Fc epsilon RII, or FcεRII, is the "low-affinity" receptor for IgE, an antibody isotype involved in allergy and resistance to parasites, and is important in regulation of IgE levels. Unlike many of the antibody receptors, CD23 is a C-type lectin. It is found on mature B cells, activated macrophages, eosinophils, follicular dendritic cells, and platelets.
In immunology, a Fc receptor is a protein found on the surface of certain cells – including, among others, B lymphocytes, follicular dendritic cells, natural killer cells, macrophages, neutrophils, eosinophils, basophils, human platelets, and mast cells – that contribute to the protective functions of the immune system. Its name is derived from its binding specificity for a part of an antibody known as the Fc region. Fc receptors bind to antibodies that are attached to infected cells or invading pathogens. Their activity stimulates phagocytic or cytotoxic cells to destroy microbes, or infected cells by antibody-mediated phagocytosis or antibody-dependent cell-mediated cytotoxicity. Some viruses such as flaviviruses use Fc receptors to help them infect cells, by a mechanism known as antibody-dependent enhancement of infection.
CD16, also known as FcγRIII, is a cluster of differentiation molecule found on the surface of natural killer cells, neutrophils, monocytes, macrophages, and certain T cells. CD16 has been identified as Fc receptors FcγRIIIa (CD16a) and FcγRIIIb (CD16b), which participate in signal transduction. The most well-researched membrane receptor implicated in triggering lysis by NK cells, CD16 is a molecule of the immunoglobulin superfamily (IgSF) involved in antibody-dependent cellular cytotoxicity (ADCC). It can be used to isolate populations of specific immune cells through fluorescent-activated cell sorting (FACS) or magnetic-activated cell sorting, using antibodies directed towards CD16.
Polymeric immunoglobulin receptor (pIgR) is a transmembrane protein that in humans is encoded by the PIGR gene. It is an Fc receptor which facilitates the transcytosis of the soluble polymeric isoforms of immunoglobulin A and immunoglobulin M (pIg) and immune complexes. pIgRs are mainly located on the epithelial lining of mucosal surfaces of the gastrointestinal tract. The composition of the receptor is complex, including 6 immunoglobulin-like domains, a transmembrane region, and an intracellular domain. pIgR expression is under the strong regulation of cytokines, hormones, and pathogenic stimuli.
Fc fragment of IgE, high affinity I, receptor for; alpha polypeptide, also known as FCER1A, is a protein which in humans is encoded by the FCER1A gene.
Low affinity immunoglobulin gamma Fc region receptor II-a is a protein that in humans is encoded by the FCGR2A gene.
CD3e molecule, epsilon also known as CD3E is a polypeptide which in humans is encoded by the CD3E gene which resides on chromosome 11.
CD244 also known as 2B4 or SLAMF4 is a protein that in humans is encoded by the CD244 gene.
Immunoglobulin lambda-like polypeptide 1 is a protein that in humans is encoded by the IGLL1 gene. IGLL1 has also recently been designated CD179B.
Immunoglobulin iota chain is a protein that in humans is encoded by the VPREB1 gene. VPREB1 has also recently been designated CD179A.
Fc fragment of IgG receptor IIb is a low affinity inhibitory receptor for the Fc region of immunoglobulin gamma (IgG). FCGR2B participates in the phagocytosis of immune complexes and in the regulation of antibody production by B lymphocytes.
Cluster of differentiation CD79A also known as B-cell antigen receptor complex-associated protein alpha chain and MB-1 membrane glycoprotein, is a protein that in humans is encoded by the CD79A gene.
High affinity immunoglobulin gamma Fc receptor I is a protein that in humans is encoded by the FCGR1A gene.
Fc fragment of IgA receptor (FCAR) is a human gene that codes for the transmembrane receptor FcαRI, also known as CD89. FcαRI binds the heavy-chain constant region of Immunoglobulin A (IgA) antibodies. FcαRI is present on the cell surface of myeloid lineage cells, including neutrophils, monocytes, macrophages, and eosinophils, though it is notably absent from intestinal macrophages and does not appear on mast cells. FcαRI plays a role in both pro- and anti-inflammatory responses depending on the state of IgA bound. Inside-out signaling primes FcαRI in order for it to bind its ligand, while outside-in signaling caused by ligand binding depends on FcαRI association with the Fc receptor gamma chain.
FCGR3B, also known as CD16b, is a human gene.
High affinity immunoglobulin epsilon receptor subunit beta is a protein that in humans is encoded by the MS4A2 gene.
CD96 or Tactile is a protein that in humans is encoded by the CD96 gene. CD96 is a receptor protein which is expressed on T cells and NK cells and shares sequence similarity with CD226. The protein encoded by this gene belongs to the immunoglobulin superfamily. It is a type I membrane protein. The protein may play a role in the adhesion of activated T and NK cells to their target cells during the late phase of the immune response. It may also function in antigen presentation. Alternative splicing occurs at this locus and two transcript variants encoding distinct isoforms have been identified. CD96 is a transmembrane glycoprotein that has three extracellular immunoglobulin-like domains and is expressed by all resting human and mouse NK cells. CD96 main ligand is CD155. CD 96 has approximately 20% homology with CD226 and competed for binding to CD155 with CD226.
Fc fragment of IgE, high affinity I, receptor for; gamma polypeptide is a protein that in humans is encoded by the FCER1G gene.