You searched for: Proteins and Peptides

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Neurotrophin-3 (NT-3) is a neurotrophic factor and a member of the nerve growth factor (NGF) family of proteins that includes neuron growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-4/5. NT-3 signals a number of trophic effects through its transducing receptor tyrosine kinase TrkC. NT-3 is known to promote survival, development, and differentiation of neurons, and modulates transmitter release at several types of synapses in the peripheral and central nervous systems (Chalazonitis 1996). NT-3 has been shown to have an important role in the overall development of enteric neurons, which are crucial for gut peristalsis (Chalazonitis 2004). Studies in rats have shown the potential of NT-3 in dorsal column axonal regeneration (Bradbury et al.). NT-3 was shown to protect neurons against amyloid-β toxicity (Lesne et al.). NT-3 has applications in neuronal differentiation protocols to generate β-tubulin III+ peripheral neurons from neural crest stem cells (Menendez et al.) and oligodendrocyte precursor cells from human embryonic stem (ES) and induced pluripotent stem (iPS) cells (Douvaras et al.).

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Oncostatin M (OSM) is a member of interleukin 6 (IL-6) family of cytokines and bears close resemblance to leukemia inhibitory factor (LIF) and granulocyte colony-stimulating factor (G-CSF) in amino acid sequence and its modulation of differentiation in a variety of cell types (Rose and Bruce). OSM signals through type I receptor (consisting of gp130 and LIF receptor [LIFR]) and type II receptor (consisting of gp130 and OSM receptor [OSMR]), which eventually activate the JAK/STAT pathway (Auguste et al.; Gómez-Lechón). OSM is primarily produced by activated T cells and monocytes, and also by activated macrophages, neutrophils, mast cells, and dendritic cells. OSM is also produced within the bone microenvironment by cells of both hematopoietic and mesenchymal origin, including osteocytes and osteoblasts. OSM is involved in differentiation, cell proliferation, hematopoiesis, and inflammation, and also has been shown to have implications in liver development and bone formation and resorption (Sims and Quinn; Tanaka and Miyajima). This product is animal component-free.

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Bone morphogenetic protein 2 (BMP-2) is a member of the transforming growth factor beta (TGF-β) superfamily. BMP-2 is a disulfide-linked homodimer, acts as a ligand for complexes of type I and II BMP receptors, and primarily activates SMAD1/5/8 signaling (Nohe et al.). BMP-2 is a potent differentiation factor and directs human pluripotent stem cells (hPSCs) towards various cell types including extra-embryonic endoderm, mesenchymal cells, and chondrocytes (Pera et al.). Although BMP-2 expression is low in healthy cartilage, its expression is upregulated at the site of cartilage damage (Blaney Davidson et al.). BMP-2 induces bone and cartilage formation in vitro and is able to induce chondrogenesis in human mesenchymal stem cells (Schmitt et al.).

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Macrophage inflammatory protein-1 beta (MIP-1 beta), also known as CCL4, is a member of the CC family of chemokines and is most closely related to CCL3 (MIP-1 alpha). Cellular sources of MIP-1 beta include activated leukocytes (monocytes and T and B cells), brain endothelial cells, and smooth muscle cells (Lukacs et al.; Menten et al.). MIP-1 beta, MIP-1 alpha, and RANTES have been shown to be major HIV-suppressive factors, possibly through the interactions of these chemokines with the receptor CCR5 on CD4+ T cells, which is also a major receptor for HIV entry into CD4+ T cells (Cocchi et al.; Menten et al.). MIP-1 beta attracts a variety of immune cells to sites of microbial infection. In addition to its chemotactic functions, MIP-1 beta induces the release of proinflammatory cytokines, mast cell degranulation, and NK cell activation (Schall et al.). In mice, recruitment of regulatory T cells to B cells and antigen-presenting cells by MIP-1 beta plays a central role in the initiation of T cell and humoral responses, and the depletion of regulatory T cells or MIP-1 beta results in deregulated humoral responses and production of autoantibodies (Bystry et al.).

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R-Spondin-3 is a member of thrombospondin type 1 repeat (TSR-1) superfamily that is involved in the canonical Wnt/β-catenin signaling pathway (de Lau et al.). R-spondin proteins are characterized by two furin-like repeats at the amino terminus and thrombospondin domain located near the carboxyl terminus (de Lau et al.). R-spondin-3 expression is associated with ovarian cancer (Gu et al.), prostate cancer (Mesci et al.), and differentiation of intestinal epithelial cells in diabetes mellitus (Shan et al.). In a transgenic mice model, the expression of R-Spondin-3 induces the expansion of Lgr5+ stem cells, Paneth cells, and Lgr4+ cells, promoting the intestinal stem cell compartment (Hilkens et al.). This protein contains a His-residue tag at the carboxyl end of the polypeptide chain.

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Interleukin 2 (IL-2) is a monomeric cytokine that was originally identified as a T cell growth factor (Gaffen and Liu). It binds to heterotrimeric receptors consisting of CD25, CD122, and CD132. Upon binding, it activates JAK3-, STAT5-, and AKT-dependent signaling pathways, which results in cellular proliferation and survival (Ma et al.). The majority of IL-2 is secreted by activated CD4+ and CD8+ T cells, although B cells and dendritic cells were found to produce IL-2 in small amounts. IL-2 downregulates immune responses to prevent autoimmunity during thymic development, influences the development of CD4+CD25+ regulatory T cells, and affects development of follicular helper T cells. IL-2 also controls inflammation by inhibiting Th17 differentiation (Banchereau et al.). High IL-2 levels in serum are associated with progression of scleroderma, rheumatoid arthritis, and gastric and non-small cell lung cancer, though no known disease can be directly attributed to the lack or excess of IL-2 (Gaffen and Liu).

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Use Interferon beta (IFN-β) to modulate the activity of genes that control dendritic cell activation, T cell survival, NK cell activation, chemokine expression, lymph node retention, and antiproliferative and antiviral effects (Dunn et al. Nat Rev Immunol, 2006). IFN-β binds to a receptor complex composed of IFNAR1 and IFNAR2, and initiates signal transduction via the JAK/STAT pathway. It is predominantly produced by fibroblasts, with smaller amounts from plasmocytoid dendritic cells. Macrophages and endothelial cells secrete IFN-β in response to viral infection (Reder and Feng. Front Immunol, 2013). IFN-β suppresses Th17 cells by affecting expression of IL-4, IL-10, and IL-27, and is a first-line treatment for multiple sclerosis. IFN-β was also shown to expand regulatory T cells and limit T cell trafficking to the central nervous system (Inoue and Shinohara. Immunology, 2013). Of the two IFN-β variants (IFN-β1 and IFN-β3), this product is the IFN-β1 form.

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Interleukin 6 (IL-6) is a pleiotropic growth factor with the wide range of biological activities in immune regulation, hematopoiesis, and oncogenesis. IL-6 is produced by a variety of cell types including T cells, B cells, monocytes and macrophages, fibroblasts, hepatocytes, vascular endothelial cells, and various tumor cell lines. On its own or in combination with other factors such as IL-2 and interferon-γ, IL-6 stimulates the proliferation of B cells, T cells, and hybridoma cells (Hirano et al.; Mihara et al.; Tanaka et al). In combination with cytokines such as IL-3, GM-CSF and SCF, IL-6 has been shown to promote hematopoietic progenitor cell proliferation and differentiation in vitro. IL-6 signals through a cell surface type I cytokine receptor complex consisting of the ligand-binding IL-6α (CD126) and the signal-transducing gp130 subunits. The binding of IL-6 to its receptor system includes activation of JAK/STAT signaling pathway (Mihara et al.; Peters et al.; Tanaka et al.).

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Use autotaxin (ENPP2) to catalyse the production of lysophosphatidic acid (LPA), a potent mitogen that can evoke growth factor-like responses (Moolenaar and Corven), from lysophospholipids in extracellular fluids. Autotaxin is a secreted glycoprotein that belongs to the ectonucleotide pyrophosphatase/phosphodiesterase (ENPP) family, containing two N-terminal somatomedin B (SMB)-like domains, a central phosphodiesterase (PDE) domain with an active catalytic site, and a C-terminal nuclease-like (NUC) domain (Nishimasu et al.). Dysregulation of autotaxin and LPA receptors is implicated in cancer (Tigyi et al.), fibrosis (Ninou et al.), neurological disorders (Roy et al.), and other inflammation-associated conditions. Both Autotaxin and LPA are overexpressed in many cancers and can promote cell proliferation, migration, and resistance to apoptotic death (Tigyi et al.). Autotaxin was also found to catalyse the production of cyclic phosphatidic acid (CPA), an analog of LPA, which has anti-mitogenic and inhibitory effects on tumor cell invasion and metastasis (Fujiwara). This protein contains a His-residue tag at the amino end of the polypeptide chain. For consistency and reproducibility across your applications, Autotaxin from STEMCELL comes lyophilised with ≥85% purity, and endotoxin levels are verified to be ≤1,0 EU/μg protein.

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Interleukin 15 (IL-15) is a four-alpha helix bundle cytokine with many similar properties to IL-2, with which it shares components of its receptor. The IL-15 receptor is a heterotrimeric receptor composed of IL-15Ra, the high-affinity receptor for IL-15, as well as IL-2/15Rb (CD122) and common gamma chain (CD132). IL-15 binds to IL-15Rα receptor and can then be presented in trans to IL-2/15Rb and common gamma chain on other cells. Trans-presentation is thought to be the major mechanism by which IL-15-mediated responses occur in mice, although may not be necessary in humans (Castillo et al.). The cytoplasmic domains of IL-2/15Rb and common gamma chain mediate signaling to activate JAK/STAT and PI3K pathways. IL-15 supports the survival and proliferation of naive CD4+ and CD8+ T cells, and promotes homeostasis of memory T cells. IL-15 also promotes the survival and differentiation of NK cells and regulates their cytolytic activity (Ma et al.).

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Fibroblast growth factor 8A (FGF-8A) is a member of the fibroblast growth factor (FGF) family and is an isoform of FGF-8. FGF-8A binds the FGF receptor (FGFR) and activates Ras/MAPK signaling (Hulstrand and Houston). The FGF family possesses broad mitogenic and cell survival activities (Folkman and Klagsbrun; Kimelman and Kirschner) and is involved in a variety of biological processes, including cell proliferation, differentiation, survival, and apoptosis (Folkman and Klagsbrun; Klagsbrun; Rifkin and Moscatelli). FGF-8 RNA is spliced to produce 4 protein isoforms in humans: FGF-8A, FGF-8B, FGF-8E, and FGF-8F. The functional differences are not fully understood; however, studies in zebrafish and Xenopus show that FGF-8A is required for endoderm morphogenesis and neurogenesis (Choe and Crump; Hulstrand and Houston).

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Activin A is a member of the transforming growth factor beta (TGF-β) family of proteins produced by many cell types throughout development (Gurdon et al.). It is a disulfide-linked homodimer (two beta-A chains) that binds to heteromeric complexes of a type I (Act RI-A and Act RI-B) and a type II (Act RII-A and Act RII-B) serine-threonine kinase receptor (Attisano et al.). Activins primarily signal through SMAD2/3 proteins to regulate a variety of functions, including cell proliferation, differentiation, wound healing, apoptosis, and metabolism (McDowell et al.). Activin A maintains the undifferentiated state of human embryonic stem cells (James et al.; Xiao et al.) and also facilitates differentiation of human embryonic stem cells into definitive endoderm (D’Amour et al.). This product is animal component-free.

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Growth differentiation factor 11 (GDF-11) is a member of transforming growth factor beta (TGF-β) family. It binds to the TGF-β receptors ALK4, ALK5, and ALK7 and activates the SMAD signaling pathway (Ho et al.). GDF-11 regulates the development of the olfactory system, retina, and pancreas, as well as anterior/posterior patterning of the axial skeleton (Lee and Lee). GDF-11 is an endocrine factor expressed in skeletal muscle, brain, and dental pulp (Kondás et al.). Studies in mice showed that GDF-11 regulates muscle and cardiac aging, and stimulates neurogenesis by remodeling blood vessels (Katsimpardi et al.; Loffredo et al.; Sinha et al.). This product is animal component-free.

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Fibroblast growth factor 10 (FGF-10) is a member of the fibroblast growth factor (FGF) family which is predominantly expressed by mesenchymal fibroblasts during embryonic development (Emoto et al.; Igarashi et al.). It binds with high affinity to fibroblast growth factor receptor 2-IIIb (FGFR2-IIIb), and also has a weaker affinity for FGFR1-IIIb (Beer et al.). FGF-10 and FGF-7 have similar receptor binding properties and target cell specificities but are differentially regulated by components of the extracellular matrix (Emoto et al.; Igarashi et al.). FGF-10 has been shown to mediate epithelial-mesenchymal interactions, which are essential to lung development (Sekine et al.; Ware and Matthay). FGF-10 also has a role in mobilisation and proliferation of lung-resident mesenchymal stem cells (MSCs) and protection and repair against acute lung injury (Tong et al.; Ware and Matthay) and endodermal differentiation of human pluripotent stem cells to insulin-producing pancreatic-like cells (Takeuchi et al.). This product is animal component-free.

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Interferon-gamma (IFN-γ), also known as type II interferon, is produced by T and NK cells, and in smaller amounts by dendritic cells and macrophages. IFN-γ is controlled by cytokines such as IL-12 and IL-18 secreted in response to infection (Schroder et al.). IFN-γ binds to a receptor complex and initiates signal transduction via the JAK/STAT pathway; this culminates in the transcription and activation of many genes that control a diverse array of immunological functions (De Weerd and Nguyen; Krause et al.). IFN-γ stimulates the antimicrobial and anti-tumor activity of macrophages, NK cells, and neutrophils (Billiau and Matthys) by promoting the activation of microbial effector functions such as production of reactive oxygen species, NO intermediates, complement, etc. (Schroder et al.). IFN-γ enhances MHC class I and II expression in dendritic cells and mononuclear phagocytes, as well as the production of IL-12 by dendritic cells. In B cells, IFN-γ stimulates survival and growth in both mouse and human cells, and redirects B cells from proliferation towards differentiation. IFN-γ favors the development of Th1 vs Th2 cells and stimulates monocyte differentiation and function (Schroder et al.).

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Macrophage inflammatory protein-4 (MIP-4) plays a role in adaptive and innate immune responses, acting as a chemoattractant for T and B lymphocytes, and natural killer cells (Krohn et al.). MIP-4 can also induce immune tolerance through its effects on dendritic cells and macrophages (Azzaoui et al., Schraufstatter et al.). In breast cancer, MIP-4 has been shown to promote the invasiveness and metastasis of cancer cells in vivo by binding PITPNM3 (Chen et al.).This small cytokine belongs to the chemokine family found only in primates. Based on amino acid sequence, MIP-4 is closely related to MIP-1 alpha (CCL3) and MIP-1 beta (CCL4) (Liang et al.). MIP-4 is produced by antigen-presenting immune cells including dendritic cells, macrophages, and monocytes (Lieshout et al.). For consistency and reproducibility across your applications, macrophage inflammatory protein-4 from STEMCELL comes lyophilised with ≥95% purity, and is verified by LAL analysis to ensure endotoxin levels are ≤1,0 EU/μg protein.

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Interferon-alpha (IFN-α) is a type I interferon, produced by virus-infected cells, and is released as a soluble factor to initiate antiviral responses (Isaacs and Lindenmann). IFN-α2 is the most potent IFN-α used in fundamental research and in most clinical applications. The best-known IFN-α2 subvariants, 2A and 2B, differ by only one or two amino acids at positions 23 and/or 34 of the mature protein (von Gabain et al.). Type I IFNs exert potent antitumor activity by increasing the cytotoxic activity of NK and T cells, as well as by inhibiting the proliferation of cancer cells (Paul et al.). Additionally, it has been shown that proinflammatory IFN-α modulates the function of B cells in patients with systemic lupus erythematosus (Chang et al.), and pegylated forms of IFN-alpha 2A and 2B have implications in the treatment of hepatitis C (Foster et al.).

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Basic fibroblast growth factor (bFGF) is a prototypic member of the fibroblast growth factor family. Cytokines in the FGF family possess broad mitogenic and cell survival activities (Folkman and Klagsbrun; Kimelman and Kirschner) and are involved in a variety of biological processes including cell proliferation, differentiation, survival, and apoptosis (Folkman and Klagsbrun; Klagsbrun; Rifkin and Moscatelli). bFGF has the β-trefoil structure (Ponting and Russell), binds to the four FGF receptor (FGFR) family members, and activates JAK/STAT, PI3K, ERK1/2, and other receptor tyrosine kinase (RTK) signaling pathways. It supports the maintenance of undifferentiated human pluripotent stem cells (Xu et al.; Kang et al.), stimulates human pluripotent stem cells to form neural rosettes (Zhang et al.), and improves proliferation of human mesenchymal stem cells and enhances chondrogenic differentiation (Solchaga et al.). This version of bFGF is the full-length bFGF protein encoded by the human FGF2 gene consisting of 154 amino acid residues. This product is animal component-free.

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Use omentin for the maintenance of insulin sensitivity and metabolism, decreasing levels of this adipokine have been associated with obesity, insulin resistance, and diabetes (Tan et al.). Studies have suggested that omentin may have protective effects against atherosclerosis, arterial calcification, and myocardial injury through AMP-activated protein kinase (AMPK) and Akt-dependent mechanisms (Xu et al., Kataoka et al.). Through regulation of Sirt1-dependent p53 deacetylation, omentin can inhibit proliferation and induce apoptosis in hepatocellular carcinoma cells (Zhang and Zhou). Omentin is mainly produced by visceral adipose tissue, but is also expressed in the small intestine, colon, mesothelial cells, vascular cells, and plasma (Watanabe et al). Protein sequence analysis has shown that omentin comprises 313 amino acids, with a secretory signal sequence and fibrinogen-related domain (Yang et al.). For consistency and reproducibility across your applications, Omentin from STEMCELL comes lyophilised with ≥90% purity, and is verified by LAL analysis to ensure endotoxin levels are ≤5,0 EU/μg protein.

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Receptor activator of nuclear factor kappa-B ligand (RANKL) is a member of the tumor necrosis factor (TNF) superfamily (Anderson et al.). Cytokines in the TNF superfamily are involved in a variety of long-term cellular activities such as differentiation, proliferation, and cell death (MacEwan). RANKL is a type II homotrimeric transmembrane protein expressed in both a membrane-bound and secreted form (Ikeda et al.). RANKL binds to the receptor activator of nuclear factor kappa-B (RANK). Upon binding to its receptor, RANKL activates the AKT signaling pathway (Moon et al.). Osteoprotegerin (OPG) may also bind RANKL, and this binding competes with RANKL-RANK binding (Lacey et al.). RANKL is involved in osteoclastogenesis (Lacey et al.; Yasuda et al.) and T cell activation (Wong et al.). This product is animal component-free.

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Interleukin 7 (IL-7) is a member of the type I cytokine family that is critical for T and B cell development and survival. It is produced by non-hematopoietic cells in the thymus, lymphoid organs, and by bone marrow stromal cells (Lundström et al.). IL-7 binds to a receptor (IL-7R) composed of common gamma chain and IL-7Ra (CD127) and signals through the JAK/STAT and PI3K pathways. IL-7 regulates the survival of naïve and memory CD4+ and CD8+ T cells, γδ T cells, NK T cells, innate lymphoid cells, and regulatory T cells (Carrette and Surh). Although a deficiency in IL-7R still permits the generation of normal numbers of peripheral B cells in humans, stimulation of human B cell precursors with IL-7 could promote STAT5-dependent proliferation and survival in vitro (Clark et al.; Corfe and Paige). This product is animal component-free.

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Interleukin 12 (IL-12p70) is a heterodimeric cytokine composed of p35 and p40 subunits. IL-12 is produced by monocytes, macrophages, dendritic cells, neutrophils, and B cells in response to bacterial products and cytokines such as IFN-γ. The IL-12 receptor is expressed on T, NK, and dendritic cells. Upon binding, IL-12 initiates signaling via the JAK/STAT signaling pathway and stimulates NK, B, and T cells to produce IFN-γ (Watford et al.). It also regulates cytokine synthesis, proliferation of T and NK cells, and stimulates differentiation of CD4+ and CD8+ T cells (Germann and Rüde). Mice that are deficient in IL-12 are susceptible to many intracellular pathogens and have impaired IFN-γ secretion, Th1 differentiation, and NK cytolytic activity; however, Th2 development and IL-4 production are enhanced (Watford et al.).

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Granulocyte-macrophage colony-stimulating factor (GM-CSF) promotes the proliferation and differentiation of hematopoietic progenitor cells and the generation of neutrophils, eosinophils, and macrophages. In synergy with other cytokines such as stem cell factor, IL-3, erythropoietin, and thrombopoietin, it also stimulates erythroid and megakaryocyte progenitor cells (Barreda et al.). GM-CSF is produced by multiple cell types, including stromal cells, Paneth cells, macrophages, dendritic cells (DCs), endothelial cells, smooth muscle cells, fibroblasts, chondrocytes, and Th1 and Th17 T cells (Francisco-Cruz et al.). The receptor for GM-CSF (GM-CSFR) is composed of two subunits: the cytokine-specific α subunit (GMRα; CD116) and the common subunit βc (CD131) shared with IL-3 and IL-5 receptors (Broughton et al.). GM-CSFR is expressed on hematopoietic cells, including progenitor cells and immune cells, as well as non-hematopoietic cells. Recombinant human GM-CSF (rhGM-CSF) promotes the production of myeloid cells of the granulocytic (neutrophils, eosinophils and basophils) and monocytic lineages in vivo. It has been tested for mobilization of hematopoietic progenitor cells and for treating chemotherapy-induced neutropenia in patients. GM-CSF is able to stimulate the development of DCs that ingest, process, and present antigens to the immune system (Francisco-Cruz et al.).

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Interleukin 2 (IL-2) is a monomeric cytokine that was originally identified as a T cell growth factor (Gaffen and Liu). It binds to a heterotrimeric receptor consisting of CD25, CD122, and CD132. Upon binding, it activates JAK3-, STAT5-, and AKT-dependent signaling pathways, which results in cellular proliferation and survival (Ma et al.). The majority of IL-2 is secreted by activated CD4+ and CD8+ T cells, although B cells and dendritic cells were found to produce IL-2 in small amounts. IL-2 downregulates immune responses to prevent autoimmunity during thymic development, influences the development of CD4+CD25+ regulatory T cells, and affects development of follicular helper T cells. IL-2 also controls inflammation by inhibiting Th17 differentiation (Banchereau et al.). Targeted deletions of the IL-2 gene in mice resulted in development of autoimmune hemolytic anemia, followed by ulcerative colitis. Similar effects were observed in mice that were deficient in IL-2 receptor α (Gaffen and Liu).

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Fibroblast growth factor 21 (FGF-21) is a member of the FGF family. Using β-Klotho as a cofactor, FGF-21 signals through FGF receptor 1c and 4 to activate PI3K and MAPK pathways (Mattila and Härkönen; Kharitonenkov et al.). FGF-21 expression is regulated by tissue-specific peroxisome proliferator-activated receptors (PPARs). Upon PPAR-α stimulation FGF-21 is produced in the liver, and activation of PPAR-γ leads to FGF-21 production in adipose tissue. FGF-21 promotes insulin-independent glucose uptake and lipid accumulation in primary human adipocytes and in mouse 3T3-L1 cells. In pancreatic islets and INS-1 cells it inhibits glucose-mediated glucagon release and stimulates insulin production. FGF-21 does not induce proliferation in immortalized cell lines, unlike other FGFs (Kharitonenkov and Shanafelt). FGF-21 regulates thermogenesis in white and brown adipose tissue, and metabolic processes in cells of pancreatic origin (Kharitonenkov et al.).

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Interleukin 2 (IL-2) is a monomeric cytokine that was originally identified as a T cell growth factor (Gaffen and Liu). It binds to heterotrimeric receptors consisting of CD25, CD122, and CD132. Upon binding, it activates JAK3-, STAT5-, and AKT-dependent signaling pathways, which results in cellular proliferation and survival (Ma et al.). The majority of IL-2 is secreted by activated CD4+ and CD8+ T cells, although B cells and dendritic cells were found to produce IL-2 in small amounts. IL-2 downregulates immune responses to prevent autoimmunity during thymic development, influences the development of CD4+CD25+ regulatory T cells, and affects development of follicular helper T cells. IL-2 also controls inflammation by inhibiting Th17 differentiation (Banchereau et al.). High IL-2 levels in serum are associated with progression of scleroderma, rheumatoid arthritis, and gastric and non-small cell lung cancer, though no known disease can be directly attributed to the lack or excess of IL-2 (Gaffen and Liu).

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Thymus-expressed chemokine (TECK), or CCL25, is a member of the CC family of chemokines that regulates the movement of lymphocytes in the thymus and in the small intestine. TECK induces chemoattraction by binding the chemokine receptor CCR9, which is expressed on immature pre-T cells and thymocytes (Youn et al.; Uehara et al.). In the thymus, TECK is produced by stromal cells, whereas in the small intestine TECK is primarily produced by epithelial cells (Vicari et al.; Bowman et al.; Kunkel et al.). CCR9 is a G protein-coupled receptor and is expressed on most thymocytes, but not on natural killer cells, monocytes, eosinophils, basophils, and neutrophils (Wu et al). In Jurkat cells, binding of TECK to CCL9 has been shown to increase levels of intracellular calcium (Cheng-Rong et al). TECK/CCR9 signaling has also been linked to many cancers, as these molecules have been shown to mediate anti-apoptotic processes by activating the PI3K/AKT signaling pathway, weakening the effect of cytotoxic T cells by regulating STAT signaling. Additionally, TECK induces metastasis by increasing the expression of MMP2 and MMP9 (Tu et al.).

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A type 1 membrane glycoprotein belonging to the immunoglobulin superfamily, cluster of differentiation 200 (CD200) binds the CD200 receptor (CD200R) that is expressed on the surface of myeloid cells and T cells (Wright et al.), and has been shown to inhibit myeloid cell activity and macrophage cytokine production (Jenmalm et al.). Homologues of CD200 have been identified in viruses and can interact with CD200R to reduce macrophage pro-inflammatory cytokine production (Foster-Cuevas et al.). Studies have shown that the immunosuppressive effects of CD200 can promote acceptance of allogeneic tissue grafts in hosts (Gorczynski et al.), whereas dysregulation of CD200/CD200R can contribute to the development of autoimmune conditions, such as rheumatoid arthritis (Ren et al.). CD200 contains two immunoglobulin-like domains, a V-type domain and a smaller C2-type domain (Hatherley et al.). This protein contains a His-residue tag at the carboxyl end of the polypeptide chain. For consistency and reproducibility across your applications, cluster of differentiation 200 from STEMCELL comes lyophilised with ≥95% purity, and is verified by LAL analysis to ensure endotoxin levels are ≤1,0 EU/μg protein. Human recombinant CD200 at 2 μg/ml can bind human CD200R (His and hFc tag) with a linear range of 5 to 28 ng/ml, as determined by functional ELISA.

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Midkine is a member of a unique family of heparin-binding growth factors that are structurally different from other fibroblast growth factors (Muramatsu; Takada et al.). Midkine is a proinflammatory cytokine, promoting the migration of leukocytes, fibrinolysis, and acting as a chemotactic agent towards neutrophils (Muramatsu; Said et al.; Takada et al.). It also regulates growth, differentiation, and development during the midgestion stage of embryogenesis, and promotes angiogenesis (Muramatsu; Said et al.; Takada et al.). The protein structure consists of three antiparallel β-sheets and is highly conserved between species (Muramatsu; Takada et al.). While the exact signal pathway is not known, proposed pathways include promoting LRP, inhibiting Src kinase, activating paxillin and STAT1α, activating PI2 and MAP kinases, suppressing caspases, binding to α6β1-integrin and tetraspanin, activating FAK, phosphorylating STAT3, suppressing STAT5 phosphorylation, activating ALK, activating PI3 kinase and transcription of NFkB, binding to neuroglycan C or nucleolin, and binding to eIF3 (Muramatsu). In cultured cells, midkine influences growth and survival of neural precursor cells, synthesis of cytokines from endothelial and renal epithelial cells, and promotes synthesis of extracellular matrices from fibroblasts (Muramatsu; Takada et al.).

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Interleukin 6 (IL-6) is a pleiotropic growth factor with a wide range of biological activities in immune regulation, hematopoiesis, and oncogenesis. IL-6 is produced by a variety of cell types including T cells, B cells, monocytes and macrophages, fibroblasts, hepatocytes, vascular endothelial cells, and various tumor cell lines. On its own or in combination with other factors such as IL-2 and interferon-γ, IL-6 stimulates the proliferation of B cells, T cells, and hybridoma cells (Nordan et al.; Van Snick et al.; Gauldie et al.; Mihara et al.; Tanaka et al). In combination with cytokines such as IL-3, GM-CSF, and SCF, IL-6 has been shown to promote hematopoietic progenitor cell proliferation and differentiation in vitro. IL-6 signals through a cell surface type I cytokine receptor complex consisting of the ligand-binding IL-6α (CD126) and the signal-transducing gp130 subunits. The binding of IL-6 to its receptor system includes activation of the JAK/STAT signaling pathway (Mihara et al.; Peters et al; Tanaka et al.).