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Fc Receptor-like Molecule
Fc receptor-like molecules (FCRLs) are a class of proteins that resemble Fc receptors. They have been characterized in a number of species, including humans and mice. They are preferentially expressed by B lymphocytes. Unlike the classical Fc receptors, there is no strong evidence that suggests that FCRLs bind to the Fc portion of antibodies. Their function is unknown. It has been indicated that FCRLs may be a unique marker for immune cells in the brain called microglia, compared to other CNS cells and peripheral immune cells. Members * FCRL1 * FCRL2 * FCRL3 * FCRL4 * FCRL5 * FCRL6 * FCRLA. FCRLA associates with IgM, IgG Immunoglobulin G (Ig G) is a type of antibody. Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in blood circulation. IgG molecules are created and released by plasma B cells. Each IgG ... and IgA. * FCRLB See also * Fc receptor References Further reading * * * * * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B Lymphocytes
B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or inserted into the plasma membrane where they serve as a part of B-cell receptors. When a naïve or memory B cell is activated by an antigen, it proliferates and differentiates into an antibody-secreting effector cell, known as a plasmablast or plasma cell. Additionally, B cells present antigens (they are also classified as professional antigen-presenting cells (APCs)) and secrete cytokines. In mammals, B cells mature in the bone marrow, which is at the core of most bones. In birds, B cells mature in the bursa of Fabricius, a lymphoid organ where they were first discovered by Chang and Glick, which is why the 'B' stands for bursa and not bone marrow as commonly believed. B cells, unlike the other two classes of lymphocytes, T cells and na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibodies
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can ''tag'' a microbe or an infected cell for attack by other parts of the immune system, or can neutralize it directly (for example, by blocking a part of a virus that is essential for its invasion). To allow the immune system to recognize millions of different antigens, the antigen-binding sites at both tips of the antibody come in an equally wide variety. In contrast, the remainder of the antibody is relatively constant. It only occurs in a few vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microglia
Microglia are a type of neuroglia (glial cell) located throughout the brain and spinal cord. Microglia account for about 7% of cells found within the brain. As the resident macrophage cells, they act as the first and main form of active immune defense in the central nervous system (CNS). Microglia (and other neuroglia including astrocytes) are distributed in large non-overlapping regions throughout the CNS. Microglia are key cells in overall brain maintenance—they are constantly scavenging the CNS for plaques, damaged or unnecessary neurons and synapses, and infectious agents. Since these processes must be efficient to prevent potentially fatal damage, microglia are extremely sensitive to even small pathological changes in the CNS. This sensitivity is achieved in part by the presence of unique potassium channels that respond to even small changes in extracellular potassium. Recent evidence shows that microglia are also key players in the sustainment of normal brain functions und ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FCRL1
Fc receptor-like protein 1 is a protein that in humans is encoded by the ''FCRL1'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b .... References Further reading * * * * * Fc receptors {{gene-1-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FCRL2
Fc receptor-like protein 2 is a protein that in humans is encoded by the ''FCRL2'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b .... References Further reading * * * * * * * * * Fc receptors {{gene-1-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FCRL3
Fc receptor-like protein 3 is a protein that in humans is encoded by the ''FCRL3'' gene. This gene encodes a member of the immunoglobulin receptor superfamily and is one of several Fc receptor-like glycoproteins clustered on the long arm of chromosome 1. The encoded protein contains immunoreceptor-tyrosine activation motif ( ITAM) and immunoreceptor-tyrosine inhibitory motif ( ITIM) in its cytoplasmic domain and may play a role in regulation of the immune system. Mutations in this gene have been associated with rheumatoid arthritis, autoimmune thyroid disease, and systemic lupus erythematosus. Structure Fc receptor-like protein 3 is a type I transmembrane glycoprotein, which consists of an extracellular region, a transmembrane domain and a cytoplasmatic tail. The extracellular region consists of five immunoglobulin-like domains, which share varying degree of homology to extracellular domains of other Fc receptor-like protein family members, as well as extracellular domains of Fc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FCRL4
Fc receptor-like protein 4 is a protein that in humans is encoded by the ''FCRL4'' gene. FCRL4 is an inhibitory receptor expressed on human memory B cells which resides in epithelial Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ... tissues. References Further reading * * * * * * Fc receptors {{gene-1-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FCRL5
Fc receptor-like protein 5 is a protein that in humans is encoded by the ''FCRL5'' gene. FCRL5 has also been designated as CD307 (cluster of differentiation The cluster of differentiation (also known as cluster of designation or classification determinant and often abbreviated as CD) is a protocol used for the identification and investigation of cell surface molecules providing targets for immunophen ... 307). References Further reading * * * * * * * * * * * External links * Clusters of differentiation Fc receptors {{membrane-protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FCRLA
Fc receptor-like A is a protein that in humans is encoded by the ''FCRLA'' gene. Receptors for the Fc fragment of IgG, or FCGRs (see MIM 146790), are cell surface glycoproteins of the Ig superfamily ( IgSF). These receptors mediate phagocytosis of IgG-coated pathogens and promote activation of effector cells, leading to inflammatory responses and antibody-mediated cellular cytotoxicity. All FCGR genes map to human chromosome 1. Additional genes in this region, including FREB, encode FCGR homologs that are selectively expressed in B cells B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or ... and may be implicated in B-cell development and lymphomagenesis. upplied by OMIMref name="entrez" /> References Further reading * * * * * * * * * * Fc receptors {{gene-1-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunoglobulin G
Immunoglobulin G (Ig G) is a type of antibody. Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in blood circulation. IgG molecules are created and released by plasma B cells. Each IgG antibody has two paratopes. Function Antibodies are major components of humoral immunity. IgG is the main type of antibody found in blood and extracellular fluid, allowing it to control infection of body tissues. By binding many kinds of pathogens such as viruses, bacteria, and fungi, IgG protects the body from infection. It does this through several mechanisms: * IgG-mediated binding of pathogens causes their immobilization and binding together via agglutination; IgG coating of pathogen surfaces (known as opsonization) allows their recognition and ingestion by phagocytic immune cells leading to the elimination of the pathogen itself; * IgG activates all the classical pathway of the complement system, a cascade of immune protein pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
