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Zap-70
ZAP-70 (Zeta-chain-associated protein kinase 70) is a protein normally expressed near the surface membrane of Lymphocyte, lymphocytes (T cells, natural killer cells, and a subset of B cell, B cells). It is most prominently known to be recruited upon antigen binding to the T cell receptor (TCR), and it plays a critical role in T cell signaling. ZAP-70 was initially discovered in TCR-stimulated Jurkat cells, an immortal line of human T lymphocytes, in 1991. Its molecular weight is 70 kDa, and it is a member of the protein-tyrosine kinase family and is a paralog, close homolog of Tyrosine-protein kinase SYK, SYK. SYK and ZAP70 share a common evolution, evolutionary origin and split from a Most recent common ancestor, common ancestor in the jawed vertebrates. The importance of ZAP-70 in T cell activation was determined when comparing ZAP-70 expression in patients with SCID (severe combined immunodeficiency). ZAP-70 deficient individuals were found to have no functioning T cells in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ZAP70 Deficiency
ZAP70 deficiency, or ZAP70 deficient SCID, is a rare autosome, autosomal dominance (genetics), recessive form of severe combined immunodeficiency (SCID) resulting in a lack of CD8+ T cells. People with this disease lack the capability to fight infections, and it is fatal if untreated. It is cause by a mutation in the ZAP70 gene. Presentation Children with this condition typically present with infections and skin rashes. Unlike many forms of SCID, absolute lymphocyte count is normal and thymus is present. Cause ZAP70 deficiency SCID is caused by a mutation is the ZAP70 gene, which is involved in the development of T cells. Diagnosis It is characterized by a lack of CD8+ T cells and the presence of circulating CD4+ T cells which are unresponsive to T-cell receptor (TCR)-mediated stimuli. Diagnosis is usually made within the first six months of life. Genetic testing is required. Treatment Hematopoietic stem cell transplantation is the only known cure for ZAP70 deficient SCID. Ep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymphocyte
A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include T cells (for cell-mediated and cytotoxic adaptive immunity), B cells (for humoral, antibody-driven adaptive immunity), and innate lymphoid cells (ILCs; "innate T cell-like" cells involved in mucosal immunity and homeostasis), of which natural killer cells are an important subtype (which functions in cell-mediated, cytotoxic innate immunity). They are the main type of cell found in lymph, which prompted the name "lymphocyte" (with ''cyte'' meaning cell). Lymphocytes make up between 18% and 42% of circulating white blood cells. Types The three major types of lymphocyte are T cells, B cells and natural killer (NK) cells. They can also be classified as small lymphocytes and large lymphocytes based on their size and appearance. Lymphocytes can be identified by their large nucleus. T cells and B cells T cells (thymus cells) and B cells ( bone marrow- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Major Histocompatibility Complex
The major histocompatibility complex (MHC) is a large Locus (genetics), locus on vertebrate DNA containing a set of closely linked polymorphic genes that code for Cell (biology), cell surface proteins essential for the adaptive immune system. These cell surface proteins are called MHC molecules. Its name comes from its discovery during the study of transplanted tissue compatibility. Later studies revealed that tissue rejection due to incompatibility is only a facet of the full function of MHC molecules, which is to bind an antigen derived from self-proteins, or from pathogens, and bring the antigen presentation to the cell surface for recognition by the appropriate T cell, T-cells. MHC molecules mediate the interactions of leukocytes, also called white blood cells (WBCs), with other leukocytes or with body cells. The MHC determines donor compatibility for organ transplant, as well as one's susceptibility to autoimmune diseases. In a cell, protein molecules of the host's own pheno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combined Immunodeficiencies
Combined immune deficiencies (CIDs) are a diverse group of inherited immune disorders characterized by impaired T lymphocyte development, function, or both, with variable B cell defects. The primary clinical manifestation of CID is infection susceptibility. Clinical manifestations of combined immunodeficiencies vary greatly, ranging from diarrhea and sinus infections to opportunistic infections caused by mycobacteria, fungi, and vaccination reactions resulting in localized to systemic symptoms. Antibiotics and immunoglobulin replacement therapy are typically administered to patients as needed. Without hematopoietic cell or other transplantation aimed at correcting the underlying pathophysiological defect, prognosis is frequently poor due to T cell dysfunction. Signs and symptoms Patients with combined immune deficiencies typically exhibit recurrent gastrointestinal and respiratory tract infections, which can be attributed to a wide variety of bacteria. However, because of T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune Deficiency
Immunodeficiency, also known as immunocompromise, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that affect the patient's immune system. Examples of these extrinsic factors include HIV infection and environmental factors, such as nutrition. Immunocompromisation may also be due to genetic diseases/flaws such as SCID. In clinical settings, immunosuppression by some drugs, such as steroids, can either be an adverse effect or the intended purpose of the treatment. Examples of such use is in organ transplant surgery as an anti- rejection measure and in patients with an overactive immune system, as in autoimmune diseases. Some people are born with intrinsic defects in their immune system, or primary immunodeficiency. A person who has an immunodeficiency of any kind is said to be immunocompromised. An immunocompromised individual may particular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systemic Lupus Erythematosus
Lupus, formally called systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common symptoms include painful and swollen joints, fever, chest pain, hair loss, mouth ulcers, swollen lymph nodes, feeling tired, and a red rash which is most commonly on the face. Often there are periods of illness, called flares, and periods of remission during which there are few symptoms. Children up to 18 years old develop a more severe form of SLE termed childhood-onset systemic lupus erythematosus. The cause of SLE is not clear. It is thought to involve a combination of genetics and environmental factors. Among identical twins, if one is affected there is a 24% chance the other one will also develop the disease. Female sex hormones, sunlight, smoking, vitamin D deficiency, and certain infections are also believed to increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytokine
Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes and mast cells, as well as Endothelium, endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell. Due to their size, cytokines cannot cross the lipid bilayer of cells to enter the cytoplasm and therefore typically exert their functions by interacting with specific cytokine receptor, cytokine receptors on the target cell surface. Cytokines are especially important in the immune system; cytokines modulate the balance between humoral immunity, humoral and cell-mediated immunity, cell-based immune responses, and they regulate the maturation, growth, and responsiveness of particular cell populations. Some cytokines enhance or inhibit the action of other cytokines in complex way ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Src Family Kinase
Src kinase family is a family of non-receptor tyrosine kinases that includes nine members: Src (gene), Src, YES1, Yes, FYN, Fyn, and FGR (gene), Fgr, forming the SrcA subfamily, Lck, HCK, Hck, Tyrosine-protein kinase BLK, Blk, and Lyn (Src family Kinase), Lyn in the SrcB subfamily, and FRK (gene), Frk in its own subfamily. Frk has homologs in invertebrates such as flies and worms, and Src homologs exist in organisms as diverse as unicellular choanoflagellates, but the SrcA and SrcB subfamilies are specific to vertebrates. Src family kinases contain six conserved domains: a N-terminal Myristoylation, myristoylated segment, a SH2 domain, a SH3 domain, a linker region, a tyrosine kinase domain, and C-terminal tail. Src family kinases interact with many cellular cytosolic, nuclear and membrane proteins, modifying these proteins by phosphorylation of tyrosine residues. A number of substrates have been discovered for these enzymes. Deregulation, including constitutive activation or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymphocyte Cytosolic Protein 2
Lymphocyte cytosolic protein 2 (SH2 domain containing leukocyte protein of 76kDa), also known as LCP2 or SLP-76, is a signal-transducing adaptor protein expressed in T cells and myeloid cells and is important in the signaling of T-cell receptors (TCRs). As an adaptor protein, SLP-76 does not have catalytic functions, primarily binding other signaling proteins to form larger signaling complexes. It is a key component of the signaling pathways of receptors with immunoreceptor tyrosine-based activation motifs (ITAMs) such as T-cell receptors, its precursors, and receptors for the Fc regions of certain antibodies. SLP-76 is expressed in T-cells and related lymphocytes like natural killer cells. Structure and function The amino acid sequence of the protein has a central domain with a high concentration of prolines, as well as domains at the amino-terminal and carboxy-terminal of the amino acid sequence. The PDB file 1H3H depicts the SH3 domain of GRAP2 in complex with an RSTK- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linker For Activation Of T Cells
The Linker for activation of T cells, also known as linker of activated T cells or LAT, is a protein involved in the T-cell receptor, T-cell antigen receptor signal transduction pathway which in humans is encoded by the ''LAT'' gene. Alternative splicing results in multiple transcript variants encoding different isoforms. Function The LAT protein encoded by the gene of the same name, plays a key role in the diversification of T cell signaling pathways following activation of the T-cell antigen receptor (T-cell receptor, TCR) signal transduction pathway, which is first catalyzed by TCR binding to MHC class II. LAT is a transmembrane protein localizes to lipid rafts (also known as glycosphingolipid-enriched microdomains or GEMs) and acts as a docking site for SH2 domain-containing proteins. Upon phosphorylation, this protein recruits multiple Signal transducing adaptor protein, adaptor proteins and downstream signaling molecules into multimolecular signaling complexes located nea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SH2-domains
The SH2 (Src Homology 2) domain is a structurally conserved protein domain contained within the Src oncoprotein and in many other intracellular signal-transducing proteins. SH2 domains bind to phosphorylated tyrosine residues on other proteins, modifying the function or activity of the SH2-containing protein. The SH2 domain may be considered the prototypical modular protein-protein interaction domain, allowing the transmission of signals controlling a variety of cellular functions. SH2 domains are especially common in adaptor proteins that aid in the signal transduction of receptor tyrosine kinase pathways. Structure and interactions SH2 domains contain about 100 amino acid residues and exhibit a central antiparallel β-sheet centered between two α-helices. Binding to phosphotyrosine-containing peptides involves a strictly-conserved Arg residue that pairs with the negatively-charged phosphate on the phosphotyrosine, and a surrounding pocket that recognizes flanking seque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD3-zeta
T-cell surface glycoprotein CD3 zeta chain also known as T-cell receptor T3 zeta chain or CD247 (Cluster of Differentiation 247) is a protein that in humans is encoded by the ''CD247'' gene. Some older literature mention a similar protein called "CD3 eta" in mice. It is now understood to be an isoform differing in the last exon. Genomics The gene is located on the long arm of chromosome 1 at location 1q22-q25 on the Crick (negative) strand. The encoded protein is 164 amino acids long with a predicted weight of 18.696 kilo Daltons. Function T-cell receptor zeta (ζ), together with T-cell receptor alpha/beta and gamma/delta heterodimers and CD3-gamma, -delta, and -epsilon, forms the T-cell receptor-CD3 complex. The zeta chain plays an important role in coupling antigen recognition to several intracellular signal-transduction pathways. Low expression of the antigen results in impaired immune response. Two alternatively spliced transcript variants encoding distinct isoforms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
