|
OX40
Tumor necrosis factor receptor superfamily, member 4 (TNFRSF4), also known as CD134 and OX40 receptor, is a member of the TNFR-superfamily of receptors which is not constitutively expressed on resting naïve T cells, unlike CD28. OX40 is a secondary co-stimulatory immune checkpoint molecule, expressed after 24 to 72 hours following activation; its ligand, OX40L, is also not expressed on resting antigen presenting cells, but is following their activation. Expression of OX40 is dependent on full activation of the T cell; without CD28, expression of OX40 is delayed and of fourfold lower levels. Function OX40 has no effect on the proliferative abilities of CD4+ cells for the first three days, however after this time proliferation begins to slow and cells die at a greater rate, due to an inability to maintain a high level of PKB activity and expression of Bcl-2, Bcl-XL and survivin. OX40L binds to OX40 receptors on T-cells, preventing them from dying and subsequently increasing cyto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OX40L
OX40L is the ligand for OX40 (also known as CD134 or TNFRSF4) and is stably expressed on many antigen-presenting cells such as DC2s (a subtype of dendritic cells), macrophages, and activated B lymphocytes. The OX40 molecule, conversely, is present on the surface of activated T lymphocytes (mainly CD4+ T cells), but also on NK cells, NKT cells, and neutrophils. The ligation of OX40-OX40L is a source of survival signal for T cells and enables the development of memory T cells. Signaling through these two molecules also leads to polarization towards Th2 immune response even in an environment with low levels of IL-4 cytokine. OX40L is also present on the surface of many non-immune cells, for example, endothelial cells and smooth muscle cells. The surface expression of OX40L is induced by many pro-inflammatory mediators, such as TNF-α, e.g. produced by mast cells, IFN-γ and PGE2 (prostaglandin E2). OX40L has also been designated CD252 (cluster of differentiation 252). Var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune Checkpoint
Immune checkpoints are regulators of the immune system. These pathways are crucial for self-tolerance, which prevents the immune system from attacking cells indiscriminately. However, some cancers can protect themselves from attack by stimulating immune checkpoint targets. Inhibitory checkpoint molecules are targets for cancer immunotherapy due to their potential for use in multiple types of cancers. Currently approved checkpoint inhibitors block CTLA4, PD-1 and PD-L1. For the related basic science discoveries, James P. Allison and Tasuku Honjo won the Tang Prize, Tang Prize in Biopharmaceutical Science and the Nobel Prize in Physiology or Medicine in 2018. Stimulatory checkpoint molecules Four stimulatory checkpoint molecules are members of the TNF receptor superfamily, tumor necrosis factor (TNF) receptor superfamily—CD27, CD40, OX40, GITR and CD137. Another two stimulatory checkpoint molecules belong to the B7-CD28 superfamily—CD28 itself and ICOS. * CD27: This molec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TNFR
The tumor necrosis factor receptor superfamily (TNFRSF) is a protein superfamily of cytokine receptors characterized by the ability to bind tumor necrosis factors (TNFs) via an extracellular cysteine-rich domain. With the exception of nerve growth factor (NGF), all TNFs are homologous to the archetypal TNF-alpha. In their active form, the majority of TNF receptors form trimeric complexes in the plasma membrane. Accordingly, most TNF receptors contain transmembrane domains (TMDs), although some can be cleaved into soluble forms (e.g. TNFR1), and some lack a TMD entirely (e.g. DcR3). In addition, most TNF receptors require specific adaptor protein such as TRADD, TRAF, RIP and FADD for downstream signalling. TNF receptors are primarily involved in apoptosis and inflammation, but they can also take part in other signal transduction pathways, such as proliferation, survival, and differentiation. TNF receptors are expressed in a wide variety of tissues in mammals, especially in leukoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRAF5
TNF receptor-associated factor 5 is a protein that in humans is encoded by the ''TRAF5'' gene. Function The scaffold protein encoded by this gene is a member of the tumor necrosis factor receptor-associated factor (TRAF) protein family and contains a meprin and TRAF homology (MATH) domain, a RING-type zinc finger, and two TRAF-type zinc fingers. TRAF proteins are associated with, and mediate signal transduction from members of the TNF receptor superfamily. This protein is one of the components of a multiple protein complex which binds to tumor necrosis factor (TNF) receptor cytoplasmic domains and mediates TNF-induced activation. Alternate transcriptional splice variants have been characterized. Interactions TRAF5 has been shown to interact with: * ASK1, * CD134, * CD30, * CD40 Cluster of differentiation 40, CD40 is a type I transmembrane protein found on antigen-presenting cells and is required for their activation. The binding of CD154 (CD40L) on T helper cell, T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunoglobulin
An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as pathogenic bacteria, bacteria and viruses, including those that cause disease. Each individual antibody recognizes one or more specific antigens, and antigens of virtually any size and chemical composition can be recognized. Antigen literally means "antibody generator", as it is the presence of an antigen that drives the formation of an antigen-specific antibody. Each of the branching chains comprising the "Y" of an antibody contains a paratope that specifically binds to one particular epitope on an antigen, allowing the two molecules to bind together with precision. Using this mechanism, antibodies can effectively "tag" the antigen (or a microbe or an infected cell bearing such an antigen) for attack by cells of the immune system, or can neutralize it directly (for example, by blocking a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Cells
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. 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: CD8+ "killer" (cytotoxic) and CD4+ "helper" T cells. (These are named for the presence of the cell surface proteins CD8 or CD4.) CD8+ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CTLA-4
Cytotoxic T-lymphocyte associated protein 4, (CTLA-4) also known as CD152 ( cluster of differentiation 152), is a protein receptor that functions as an immune checkpoint and downregulates immune responses. CTLA-4 is constitutively expressed in regulatory T cells but only upregulated in conventional T cells after activation – a phenomenon which is particularly notable in cancers. It acts as an "off" switch when bound to CD80 or CD86 on the surface of antigen-presenting cells. It is encoded by the gene ''CTLA4'' in humans. The CTLA-4 protein is encoded by the ''Ctla-4'' gene in mice. History CTLA-4 was first identified in 1991 as a second receptor for the T cell costimulation ligand B7. In November 1995, the labs of Tak Wah Mak and Arlene Sharpe independently published their findings on the discovery of the function of CTLA-4 as a negative regulator of T-cell activation, by knocking out the gene in mice. Previous studies from several labs had used methods which could ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TLR9
Toll-like receptor 9 is a protein that in humans is encoded by the ''TLR9'' gene. TLR9 has also been designated as CD289 (cluster of differentiation 289). It is a member of the toll-like receptor (TLR) family. TLR9 is an important receptor expressed in immune system cells including dendritic cells, macrophages, natural killer cells, and other antigen presenting cells. TLR9 is expressed on endosomes internalized from the plasma membrane, binds DNA (preferentially DNA containing unmethylated CpGs of bacterial or viral origin), and triggers signaling cascades that lead to a pro-inflammatory cytokine response. Cancer, infection, and tissue damage can all modulate TLR9 expression and activation. TLR9 is also an important factor in autoimmune diseases, and there is active research into synthetic TLR9 agonists and antagonists that help regulate autoimmune inflammation. Function The TLR family plays a fundamental role in pathogen recognition and activation of innate immunity. TLRs a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agonistic
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology The word originates from the Greek word (''agōnistēs''), "contestant; champion; rival" < (''agōn''), "contest, combat; exertion, struggle" < (''agō''), "I lead, lead towards, conduct; drive." Types of agonists can be activated by either ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusion Protein
Fusion proteins or chimeric (kī-ˈmir-ik) proteins (literally, made of parts from different sources) are proteins created through the joining of two or more genes that originally coded for separate proteins. Translation of this '' fusion gene'' results in a single or multiple polypeptides with functional properties derived from each of the original proteins. ''Recombinant fusion proteins'' are created artificially by recombinant DNA technology for use in biological research or therapeutics. '' Chimeric'' or ''chimera'' usually designate hybrid proteins made of polypeptides having different functions or physico-chemical patterns. ''Chimeric mutant proteins'' occur naturally when a complex mutation, such as a chromosomal translocation, tandem duplication, or retrotransposition creates a novel coding sequence containing parts of the coding sequences from two different genes. Naturally occurring fusion proteins are commonly found in cancer cells, where they may function as oncop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avian Influenza
Avian influenza, also known as avian flu or bird flu, is a disease caused by the influenza A virus, which primarily affects birds but can sometimes affect mammals including humans. Wild aquatic birds are the primary host of the influenza A virus, which is enzootic (continually present) in many bird populations. Symptoms of avian influenza vary according to both the strain of virus underlying the infection, and on the species of bird or mammal affected. Classification of a virus strain as either low pathogenic avian influenza (LPAI) or high pathogenic avian influenza (HPAI) is based on the severity of symptoms in domestic chickens and does not predict severity of symptoms in other species. Chickens infected with LPAI display mild symptoms or are asymptomatic, whereas HPAI causes serious breathing difficulties, significant drop in egg production, and sudden death. Domestic poultry may potentially be protected from specific strains of the virus by vaccination. Humans and other ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
