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Memory T Cells
Memory T cells are a subset of T lymphocytes that might have some of the same functions as memory B cells. Their lineage is unclear. Function Antigen-specific memory T cells specific to viruses or other microbial molecules can be found in both central memory T cells (TCM) and effector memory T cells (TEM) subsets. Although most information is currently based on observations in the cytotoxic T cells (CD8-positive) subset, similar populations appear to exist for both the helper T cells (CD4-positive) and the cytotoxic T cells. Primary function of memory cells is augmented immune response after reactivation of those cells by reintroduction of relevant pathogen into the body. It is important to note that this field is intensively studied and some information may not be available as of yet. * Central memory T cells (TCM): TCM lymphocytes have several attributes in common with stem cells, the most important being the ability of self-renewal, mainly because of high level of phosphory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Lymphocyte
T cells (also known as T lymphocytes) are an important part of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface receptor, cell surface. T cells are born from hematopoietic stem cells, found in the bone marrow. Developing T cells then migrate to the thymus gland to develop (or mature). T cells derive their name from the thymus. After migration to the thymus, the precursor cells mature into several distinct types of T cells. T cell differentiation also continues after they have left the thymus. Groups of specific, differentiated T cell subtypes have a variety of important functions in controlling and shaping the immune response. One of these functions is immune-mediated cell death, and it is carried out by two major subtypes: Cytotoxic T cell, CD8+ "killer" (cytotoxic) and T helper cell, CD4+ "helper" T cells. (These are named for the presen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antigen
In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. Antigens can be proteins, peptides (amino acid chains), polysaccharides (chains of simple sugars), lipids, or nucleic acids. Antigens exist on normal cells, cancer cells, parasites, viruses, fungus, fungi, and bacteria. Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. In most cases, antibodies are ''antigen-specific'', meaning that an antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymph Node
A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that include B and T cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles including cancer cells, but have no detoxification function. In the lymphatic system, a lymph node is a secondary lymphoid organ. A lymph node is enclosed in a fibrous capsule and is made up of an outer cortex and an inner medulla. Lymph nodes become inflamed or enlarged in various diseases, which may range from trivial throat infections to life-threatening cancers. The condition of lymph nodes is very important in cancer staging, which decides the treatment to be used and determines the prognosis. Lymphadenopathy refers to glands that are enlarged or swollen. When inflamed or enlarged, lymph nodes can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD44
The CD44 antigen is a cell-surface glycoprotein involved in cell–cell interactions, cell adhesion and migration. In humans, the CD44 antigen is encoded by the ''CD44'' gene on chromosome 11. CD44 has been referred to as HCAM (homing cell adhesion molecule), Pgp-1 (phagocytic glycoprotein-1), Hermes antigen, lymphocyte homing receptor, ECM-III, and HUTCH-1. Tissue distribution and isoforms CD44 is expressed in a large number of mammalian cell types. The standard isoform, designated CD44s, comprising exons 1–5 and 16–20 is expressed in most cell types. CD44 splice variants containing variable exons are designated CD44v. Some epithelial cells also express a larger isoform (CD44E), which includes exons v8–10. Function CD44 participates in a wide variety of cellular functions including lymphocyte activation, recirculation and homing, hematopoiesis, and tumor metastasis. CD44 is a receptor for hyaluronic acid and internalizes metals bound to hyaluronic acid and can a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L-selectin
L-selectin, also known as CD62L, is a cell adhesion molecule found on the cell surface of leukocytes, and the blastocyst. It is coded for in the human by the ''SELL'' gene. L-selectin belongs to the selectin family of proteins, which recognize sialylated carbohydrate groups containing a Sialyl LewisX (sLeX) determinant. L-selectin plays an important role in both the innate and adaptive immune responses by facilitating leukocyte-endothelial cell adhesion events. These tethering interactions are essential for the trafficking of monocytes and neutrophils into inflamed tissue as well as the homing of lymphocytes to secondary lymphoid organs. L-selectin is also expressed by lymphoid primed hematopoietic stem cells and may participate in the migration of these stem cells to the primary lymphoid organs. In addition to its function in the immune response, L-selectin is expressed on embryonic cells and facilitates the attachment of the blastocyst to the endometrial endothelium during human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-C Chemokine Receptor Type 7
C-C chemokine receptor type 7 is a protein that in humans is encoded by the ''CCR7'' gene. Two ligands have been identified for this receptor: the chemokines (C-C motif) ligand 19 ( CCL19/ELC) and (C-C motif) ligand 21 (CCL21). The ligands have similar affinity for the receptor, though CCL19 has been shown to induce internalisation of CCR7 and desensitisation of the cell to CCL19/CCL21 signals. CCR7 is a transmembrane protein with 7 transmembrane domains, which is coupled with heterotrimeric G proteins, which transduce the signal downstream through various signalling cascades. The main function of the receptor is to guide immune cells to immune organs (lymph nodes, thymus, spleen) by detecting specific chemokines, which these tissues secrete. CCR7 has also recently been designated CD197 (cluster of differentiation 197). Function The protein encoded by this gene is a member of the G protein-coupled receptor family. This receptor was identified as a gene induced by the Epstein– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD45
Protein tyrosine phosphatase, receptor type, C also known as PTPRC is an enzyme that, in humans, is encoded by the ''PTPRC'' gene. PTPRC is also known as CD45 antigen (CD stands for cluster of differentiation), which was originally called leukocyte common antigen (LCA). PTPRC is a critical enzyme involved in regulating immune cell function. PTPRC is a transmembrane protein tyrosine phosphatase expressed on the surface of all nucleated hematopoietic cells, particularly lymphocytes. It plays a key role in the activation and differentiation of T cells, B cells, and other immune cells by modulating signaling pathways. It functions by dephosphorylating specific tyrosine residues on target proteins, thereby controlling various signaling processes essential for immune response and homeostasis. Function The protein product of this gene, best known as CD45, is a member of the protein tyrosine phosphatase (PTP) family. PTPs are signaling molecules that regulate a variety of cellular pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virtual Memory T Cell
Virtual memory T cells (TVM) are a subtype of T lymphocytes. These are cells that have a memory phenotype but have not been exposed to a foreign antigen. They are classified as memory cells but do not have an obvious memory function. They were first observed and described in 2009. The name comes from a computerized "virtual memory" that describes a working memory based on an alternative use of an existing space. Origin TVM arise from autoreactive T cells during the thymus section. Autoreactive lymphocytes are commonly removed in the thymus because they recognize the body's own structure and could induce autoimmune disease. However, some autoreactive CD8+ T cells are intended for development into TVM. This process is controlled by CD8- Lck. The generation and maintenance of the TVM population depends on the transcription factors Eomes and IRF4, type I interfering signaling. The presence of the IL-15 cytokine is then essential. Function The existence of memory T cells is also kno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IL17A
Interleukin-17A is a protein that in humans is encoded by the ''IL17A'' gene. In rodents, IL-17A used to be referred to as CTLA8, after the similarity with a viral gene (). Function The protein encoded by this gene is a proinflammatory cytokine produced by activated T cells. This cytokine regulates the activities of NF-kappaB and mitogen-activated protein kinases. This cytokine can stimulate the expression of IL6 and cyclooxygenase-2 ( PTGS2/COX-2), as well as enhance the production of nitric oxide (NO). Discovery IL-17A, often referred to as IL-17, was originally discovered at transcriptional level by Rouvier et al. in 1993 from a rodent T-cell hybridoma, derived from the fusion of a mouse cytotoxic T cell clone and a rat T cell lymphoma. Human and mouse IL-17A were cloned a few years later by Yao and Kennedy. Lymphocytes including CD4+, CD8+, gamma-delta T (γδ-T), invariant NKT and innate lymphoid cells (ILCs) are primary sources of IL-17A. Non-T cells, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 4
The interleukin 4 (IL4, IL-4) is a cytokine that induces differentiation of naive helper T cells ( Th0 cells) to Th2 cells. Upon activation by IL-4, Th2 cells subsequently produce additional IL-4 in a positive feedback loop. IL-4 is produced primarily by mast cells, Th2 cells, eosinophils and basophils. It is closely related and has functions similar to IL-13. Function Interleukin 4 has many biological roles, including the stimulation of activated B cell and T cell proliferation, and the differentiation of B cells into plasma cells. It is a key regulator in humoral and adaptive immunity. IL-4 induces B cell class switching to IgE, and up-regulates MHC class II production. IL-4 decreases the production of Th1 cells, macrophages, IFNγ, and dendritic cells IL-12. Overproduction of IL-4 is associated with allergies. * Inflammation and wound repair Tissue macrophages play an important role in chronic inflammation and wound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interferon Gamma
Interferon gamma (IFNG or IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. Wheelock as a product of human leukocytes stimulated with phytohemagglutinin, and by others as a product of antigen-stimulated lymphocytes. It was also shown to be produced in human lymphocytes. or tuberculin-sensitized mouse peritoneal lymphocytes challenged with Mantoux test (PPD); the resulting supernatants were shown to inhibit growth of vesicular stomatitis virus. Those reports also contained the basic observation underlying the now widely employed interferon gamma release assay used to test for tuberculosis. In humans, the IFNG protein is encoded by the ''IFNG'' gene. Through cell signaling, interferon gamma plays a role in regulating the immune response of its target cell. A key signaling pathway that is activated by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigenetics
In biology, epigenetics is the study of changes in gene expression that happen without changes to the DNA sequence. The Greek prefix ''epi-'' (ἐπι- "over, outside of, around") in ''epigenetics'' implies features that are "on top of" or "in addition to" the traditional (DNA sequence based) genetic mechanism of inheritance. Epigenetics usually involves a change that is not erased by cell division, and affects the regulation of gene expression. Such effects on cellular and physiological traits may result from environmental factors, or be part of normal development. The term also refers to the mechanism of changes: functionally relevant alterations to the genome that do not involve mutation of the nucleotide sequence. Examples of mechanisms that produce such changes are DNA methylation and histone modification, each of which alters how genes are expressed without altering the underlying DNA sequence. Further, non-coding RNA sequences have been shown to play a key role in the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
