You searched for: Proteins and Peptides

Supplier: Adipogen

Interleukin-21 (IL-21) is a key factor in the transition between innate and adaptive immune responses secreted by activated T cells. The IL-21 receptor (IL-21R) is expressed in lymphoid tissue, in particular by NK, B, T and dendritic cells, macrophages and endothelial cells. Recent evidence suggests that IL-21 plays a supportive role in the proliferation of T and B cells and influences the cytolytic activity of natural killer cells. IL-21 has been shown to up-regulate genes associated with innate immunity and to inhibit the differentiation of naïve T helper cells. IL-21 specifically inhibits IFN-gamma production from developing TH1 cells and is preferentially expressed by TH2 cells. Furthermore IL-21 has been identified as a growth and survival factor for human myeloma cells. IL-21/IL-21R interactions have a unique role in sequentially activating both innate and adaptive immune responses against poorly immunogenic tumors, leading to tumor rejection that is perforin dependent but IFN-gamma independent.

Supplier: Adipogen

Interleukin-15 (IL-15) has a broad spectrum of biological activities. It is crucial for the development, proliferation, survival and differentiation of multiple cells from both innate and adaptive immune systems. IL-15 up-regulation has a central role in the development of several autoimmune or chronic inflammatory disorders. Targeting IL-15 or its receptor may have a valuable impact on the treatment of immune-mediated diseases. IL-15 participates in the development of important immune antitumor mechanisms. It activates CD8(+) T cells, natural killer (NK) cells, NK T cells, and can promote the formation of antitumor antibodies. IL-15 can also protect T effector cells from the action of T regulatory cells and reverse tolerance to tumor-associated antigens. In pre-clinical studies IL-15 has been found to demonstrate potentiated antitumor effects following pre-association with IL-15Ralpha, or when used in combination with chemotherapy, adoptive therapy, monoclonal antibodies, and tumor vaccines.

Supplier: STEMCELL Technologies

Persephin is a neurotrophic factor that belongs to the glial cell line-derived neurotrophic factor (GDNF) family. Persephin shares a large degree of structural similarity to GDNF, artemin, and neurturin, and has overall neuroprotective activity. Persephin signals through GRFα4 (glycosylphosphatidylinositol (GPI)-linked GDNF receptor family member) which signals through the receptor tyrosine kinase RET. Unlike GDNF and neurturin, persephin only promotes the growth and survival of central dopaminergic and motor neurons, but not peripheral neurons (Milbrandt et al.). in vitro, persephin only promotes survival of neurons that co-express GPI-linked GRFα4 and RET (Enokido et al.; Lindahl et al.). Mice lacking persephin showed increased cell death after cerebral ischemia, however administration of persephin before ischemia dramatically reduced neuronal cell death (Tomac et al.).

Supplier: STEMCELL Technologies

Fibroblast growth factor 7 (FGF-7) is a member of the FGF family, and acts exclusively through a subset of FGF receptor isoforms expressed predominantly by epithelial cells (Finch and Rubin). FGF-7 seems to act specifically on epithelial cells and stimulates proliferation, migration, and differentiation of these cells, and also participates in epithelial protection and repair both in vitro and in vivo (Finch and Rubin; Werner). In contrast, FGF-7 is produced solely by cells of mesenchymal origin, and functions as a paracrine mediator of mesenchymal-epithelial communication (Rubin et al.). FGF-7 has also been shown to supplement several wound-healing properties of bioengineered skin (Erdag et al.) and to induce autophagy in human keratinocytes (Belleudi et al.). Additionally, FGF-7 has a role in pluripotent stem cell differentiation to endodermal pancreatic-like insulin-producing cells and thymic epithelial cells (Inami et al.; Niu et al.).

Supplier: STEMCELL Technologies

Platelet-derived growth factor (PDGF) is a dimeric glycoprotein consisting of two disulfide bridge stabilized polypeptide chains, A and B, which are assembled as heterodimers (PDGF-AB) or homodimers (PDGF-AA and PDGF-BB) (Fretto et al.; Westermark and Heldin). PDGF signals through the receptor tyrosine kinases PDGFRalpha and PDGFRbeta. It has been shown that PDGF-induced migration involves signaling pathways involving MEK/ERK, EGFR, Src and PI3K/AKT (Kim et al.). PDGF is a potent mitogen for cells of mesenchymal origin- like fibroblasts, glial cells, and vascular smooth muscle cells. PDGF has been implicated in pathogenesis of atherosclerosis, glomerulonephritis, cancer, and in the contraction of vascular smooth muscle cells of rat aortic tissues (Fretto et al.; Sachinidis et al.). PDGF-BB is secreted by osteoblasts to induce mesenchymal stem cell migration and angiogenesis. It has also been shown that PDGF-BB is secreted by preosteoclasts during bone modeling and remodeling to induce angiogenesis and thus proper osteogenesis (Xie et al.).

Supplier: STEMCELL Technologies

RANTES (regulated upon activation, normal T cell expressed and secreted), also known as CCL5, is a member of the CC family of chemokines and is able to recruit leukocytes to sites of inflammation (Schall et al.). RANTES is secreted by T lymphocytes, macrophages, platelets, synovial fibroblasts, tubular epithelium, and certain types of tumor cells (Aldinucci and Colombatti; Soria and Ben-Baruch). This chemokine exerts its effect by interacting with the chemokine receptors CCR1, CCR3, CCR4, and CCR5. RANTES plays an active role in recruiting a variety of leukocytes into inflammatory sites, including T cells, macrophages, eosinophils, and basophils. In collaboration with certain cytokines that are released by T cells such as IL-2 and IFN-γ, RANTES also induces the activation and proliferation of NK cells to generate CC chemokine-activated killer cells, which are highly cytolytic (Lv et al.; Maghazachi et al.). It has been shown that RANTES produced by CD8+ T cells inhibits HIV infection of primary human peripheral blood mononuclear cells (Appay and Rowland-Jones; Cocchi et al.).

Supplier: ADVANCED BIOMATRIX, INC. MS

RatCol® Type I Acid Soluble Rat Tail Collagen contains 100 mg at a concentration of approximately 4 mg/mL in a 0.02M acetic acid solution (pH 2 to 3). RatCol® collagen is soluble telo-collagen. Each product includes a bottle containing 100 mg of collagen solution accompanied with a bottle of pre-formulated neutralizing solution for the formation of a collagen gel. This collagen product is provided in user-friendly packaging for use and storage. This product is sterile filtered and is supplied as a ready to use solution. The concentration for each specific lot is provided on the product label and on a Certificate of Analysis that is available with the purchase of each product.

This product is ideal for coating of surfaces, providing preparation of thin layers for culturing cells, or use as a solid gel. RatCol® collagen is suitable for applications using a variety of cell lines including hepatocytes, fibroblasts and epithelial cells.

Supplier: STEMCELL Technologies

Use resistin to modulate various cellular responses, such as promoting neutrophil extracellular trap (NET) formation (Jiang et al.) and regulating anti-inflammatory signaling pathways through toll-like receptor 4 (TLR4) (Jang et al., 2017). A member of the resistin-like molecule (RELM) family, resistin is produced by adipocytes in mice, and has been implicated in insulin resistance, reducing glucose tolerance, and insulin sensitivity in vivo (Li et al.). In humans, resistin is expressed predominantly in leukocytes, modulating inflammation in numerous diseases (Jamaluddin et al.; Jang et al., 2015; Mantula et al.). Studies also show that resistin facilitates vascular endothelial growth factor (VEGF)-A-dependent angiogenesis in human chondrosarcoma cells, highlighting it as a promising target for chondrosarcoma angiogenesis (Chen et al.). For consistency and reproducibility across your applications, resistin from STEMCELL comes lyophilized with ≥ 95% purity, and endotoxin levels are verified to be ≤1.0 EU/μg protein.

Supplier: STEMCELL Technologies

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.).

Supplier: STEMCELL Technologies

R-Spondin-1 (RSPO1) is the prototype member of the R-Spondin (RSPO) protein subfamily of a superfamily of thrombospondin type 1 repeat (TSR-1)-containing proteins (Chen et al.; Kamata et al.; Kazanskaya et al.; Kim et al.). Although unable to initialize signaling, RSPO family members are potent enhancers of WNT signaling (Cruciat and Niehrs; de Lau et al.; Kamata et al.; Kazanskaya et al.). They are characterized by a TSR-1 domain, a carboxy-terminal region with positively charged amino acids, and two N-terminal furin-like cysteine-rich repeats (Glinka et al.; Kazanskaya et al.). R­-Spondin-1 activates β­-catenin signaling via the WNT signaling cascade and by indirectly increasing low-density lipoprotein receptor-related protein 6 (LRP6) on the cell surface. It does this by binding leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), and competing with WNT antagonist DKK­1 for binding to the WNT co­receptors, Kremen and LRP­6, which reduces DKK­1-­mediated internalization of LRP6 (Binnerts et al.). RSPO1 is involved in a wide range of pleiotropic roles during embryogenesis, it is required for the specification of hematopoietic stem cells, and it has been shown to be important in the growth, survival, and migration of ovarian cancer cells (Cruciat and Niehrs; de Lau et al.; Genthe and Clements; Liu et al.).

Supplier: STEMCELL Technologies

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.). This product is animal component-free.

Supplier: STEMCELL Technologies

Interleukin 21 (IL-21) is a pleiotropic cytokine that is composed of four α-helical bundles and primarily produced by natural killer T (NKT) cells, T follicular helper (Tfh) cells, and Th17 cells (Spolski and Leonard 2008). IL-21 signals via heterodimers of the IL-21 receptor (IL-21R) and the IL2RG encoded common cytokine receptor γ-chain (Parrish-Novak et al.; Ozaki K et al. 2000), and utilizes the JAK/STAT, MAPK, and PI3K pathways (Spolski and Leonard 2014). IL-21 has been shown to have a critical role in regulating immunoglobulin production and differentiation of the pro-inflammatory Th17 population of cells (Ozaki et al. 2002; Nurieva et al.). Additionally, IL-21 specifically sustains CD8+ T cell effector activity and provides a mechanism of CD4+ T cell help during chronic viral infection (Elsaesser et al.). IL-21 signaling was also found critical for the development of type 1 diabetes in NOD mice (Sutherland et al.) and control of T cell autoimmunity by regulatory B cells (Yoshizaki et al.).

Supplier: STEMCELL Technologies

Fibroblast growth factor acidic (FGF-acidic), also known as FGF-1, is a potent activator of DNA synthesis, cell proliferation, and chemotaxis and is known to play numerous roles in development, regeneration, and angiogenesis (Galzie et al.; Jaye et al.; Presta et al.). FGF-acidic is produced by multiple cell types and is capable of activating all cells of mesodermal origin and many cells of neuroectodermal, ectodermal, and endodermal origin. It is found in large quantities in the brain, but is also expressed in hepatocytes, vascular smooth muscle cells, neurons of the central nervous system, skeletal muscle cells, fibroblasts, keratinocytes, endothelial cells, intestinal columnar epithelial cells, and pituitary basophils and acidophils. FGF-acidic is secreted as a disulfide-linked homodimer and is stored in complex with heparan sulfate, a requirement for its interaction with FGF receptors (Guerrini et al.; Mohammadi et al.). Internalized FGF-acidic signals via protein kinase C and promotes cell survival by inhibiting p53 and proapoptotic signaling (Bouleau et al.). This product is animal component-free.

Supplier: STEMCELL Technologies

Fibroblast growth factor 7 (FGF-7) is a member of the FGF family, and acts exclusively through a subset of FGF receptor isoforms expressed predominantly by epithelial cells (Finch and Rubin). FGF-7 seems to act specifically on epithelial cells and stimulates proliferation, migration, and differentiation of these cells, and also participates in epithelial protection and repair both in vitro and in vivo (Finch and Rubin; Werner). In contrast, FGF-7 is produced solely by cells of mesenchymal origin, and functions as a paracrine mediator of mesenchymal-epithelial communication (Rubin et al.). FGF-7 has also been shown to supplement several wound-healing properties of bioengineered skin (Erdag et al.) and to induce autophagy in human keratinocytes (Belleudi et al.). Additionally, FGF-7 has a role in the differentiation of pluripotent stem cell to endodermal pancreatic-like insulin-producing cells and thymic epithelial cells (Inami et al.; Niu et al.). This product is animal component-free.

Supplier: Adipogen

CD276 (B7-H3) is a member of the B7/CD28 superfamily of costimulatory molecules serving as an accessory modulator of T cell response. B7 family molecules, which are expressed on antigen-presenting cells and display extracellular regions containing immunoglobulin (Ig) variable (V)- and constant (C)-like domains, are known to modulate T cell receptor (TCR)-mediated T cell activation by providing co-signals that are either stimulatory or inhibitory. B7-H3 provides a stimulatory signal to T cells. However, recent studies suggest a negative regulatory role for B7-H3 in T cell responses. B7-H3 inhibited T cell proliferation mediated by antibody to T cell receptor or allogeneic antigen-presenting cells. B7-H3 is a negative regulator that preferentially affects T(H)1 responses. B7-H3 may play an important role in muscle-immune interactions, providing further evidence of the active role of muscle cells in local immunoregulatory processes. Recently, B7-H3 expression has also been found in a variety of different human cancers, including prostate cancer, clear cell renal cell carcinoma (ccRCC), non-small-cell lung cancer (NSCLC), pancreatic cancer, gastric cancer, ovarian cancer, colorectal cancer (CRC) and urothelial cell carcinoma. B7-H3 was expressed in some human cancers and correlated with poor outcome of cancer patients.

Supplier: STEMCELL Technologies

Complement factor D is a component of the alternative pathway of the complement system and part of the innate immune system, playing a vital role in the initiation and amplification of complement activation, in order to defend against infection (Barratt and Weitz). A serine protease belonging to the S1 peptidase family, complement factor D is secreted by adipocytes into circulating blood, and is also expressed by macrophages and monocytes (White et al.). In the initiation phase of the complement pathway, complement factor D cleaves complement factor B (bound to component C3) to produce a complex known as C3 convertase. During the amplification phase, complement factor D cleaves complement factor B (bound to component C3b) to produce the C3bBb convertase, and is involved in the propagation of complement activation. In addition to its immunological role, complement factor D is involved in other physiological processes, such as the efficient clearing of damaged cell debris by phagocytes following acute liver injury (Cresci et al.). Complement factor D deficiency is associated with an increased susceptibility to pathogens like Neisseria meningitidis (Biesma et al.). This protein contains a His-residue tag at the carboxyl end of the polypeptide chain. For consistency and reproducibility across your applications, complement factor D from STEMCELL comes lyophilized with ≥94% purity, and is verified by LAL analysis to ensure endotoxin levels are ≤1.0 EU/μg protein.

Supplier: ADVANCED BIOMATRIX, INC. MS

Poly-L-Lysine is a synthetic amino acid chain that is positively charged having one hydrobromide per unit of Lysine. Poly-L-Lysine is widely used as a coating to enhance cell attachment and adhesion to both plasticware and glass surfaces. This molecule has been used to culture a wide variety of cell types. Certain cell types secrete proteases, which can digest Poly-L-Lysine. For those cell types, Poly-D-Lysine 000 Da) being less viscous and higher molecular weight (>300,000 Da) having more binding sites per molecule. This product’s molecular weight ranges from 70,000 to 150,000 Da yielding a solution viscosity for easy handling while providing sufficient binding sites for cell attachment.

Poly-L-Lysine surface coatings are designed to improve cell attachment, growth and differentiation of many cell types. Coated surfaces will often improve cell attachment in reduced or serum-free conditions. This product is supplied in a sterile 50 ml package size at a concentration of 0.1 mg/ml.

Supplier: STEMCELL Technologies

Interleukin 17A (IL-17A) is the founding member of the family of cytokines that includes IL-17B through IL-17F. It is a potent pro-inflammatory cytokine that plays a key role in defense against pathogens. IL-17A and IL-17F signal as homodimers or heterodimers through the same receptor, and activate NF-κB, MAPK, and C/EBP pathways (Gaffen). IL-17A is produced by Th17 cells, CD8+ T cells, γ/δ T cells, natural killer (NK) T cells, B cells, innate lymphoid cells, and mesenchymal stromal cells (MSCs) (Cua and Tato; Gaffen; Mojsilović et al.). IL-17A mediates protection against extracellular pathogens, and together with IL-22 stimulates production of antimicrobial peptides. It induces granulopoiesis factors and neutrophil-specific chemokines. Together with tumor necrosis factor alpha (TNF-α), IL-17A induces a sustained neutrophil recruitment during inflammation (Cua and Tato). IL-17A receptor is expressed at particularly high levels on stromal cells, including MSCs. IL-17A increases the frequency and the average size of fibroblast colony-forming units (CFU-F), as well as the proliferation of marrow-derived MSCs. It enhances osteogenic differentiation, and inhibits adipocyte differentiation and chondrogenesis (Mojsilović et al.).

Supplier: STEMCELL Technologies

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 lyophilized 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.

Supplier: ADVANCED BIOMATRIX, INC. MS

Poly-L-Ornithine is a synthetic amino acid chain that is positively charged having one hydrobromide per unit of ornithine. Poly-L-Ornithine is widely used as a coating to enhance cell attachment and adhesion to both plasticware and glass surfaces.

The molecular weight of Poly-L-Ornithine can vary significantly with lower molecular weight (30,000 Da) being less viscous and higher molecular weight (>300,000 Da) having more binding sites per molecule. This product’s molecular weight ranges from 70,000 to 150,000 Da yielding a solution viscosity for easy handling while providing sufficient binding sites for cell attachment.

Poly-L-Ornithine surface coatings are designed to improve cell attachment, growth and differentiation of many cell types. Coated surfaces will often improve cell attachment in reduced or serum-free conditions. This product is supplied in a sterile 50 ml package size at a concentration of 0.1 mg/ml.

Supplier: STEMCELL Technologies

Stromal cell-derived factor 1 alpha (SDF-1α) is a member of the CXC group of chemokines that binds to the G-protein coupled receptor, CXCR4, to regulate migration, proliferation, differentiation, and survival of many cell types including hematopoietic stem cells, B cells, and T cells. It is produced by bone marrow stromal cells, osteoblasts, endothelial cells, and neuronal cells. SDF-1α was first identified as the pre-B-cell growth-stimulating factor (PBSF) in the mouse bone marrow-derived stromal cell line, PA6, in the growth of B cell precursors (Hayashi et al.). SDF-1α primarily regulates cell motility during development and adulthood, including the homing of hematopoietic stem cells and neutrophils to fetal bone marrow during ontogeny (Ara et al. 2003a) and the recruitment of endothelial progenitor cells from bone marrow during angiogenesis in adulthood (Zheng et al.). In addition to its role in hematopoiesis, the SDF-1α/CXCR4 signaling pathway is also essential for the homing of primordial germ cells to gonads (Ara et al. 2003b), the migration of granule cells in the cerebellum during neurogenesis (Zou et al.), and the migration of breast cancer cells to sites of metastasis (Muller et al.).

Supplier: Adipogen

Interleukin-33 (IL-33; HF-NEV; IL-1F11), a member of the IL-1 family of cytokines, is expressed by many cell types following pro-inflammatory stimulation and is thought to be released upon cell lysis. IL-33 binds to and signals through ST2 (IL-1R1) and its stimulation recruits MYD88, IRAK, IRAK4 and TRAF6, followed by phosphorylation of ERK1 (MAPK3) / ERK2 (MAPK1), p38 (MAPK14) and JNK. The ability of IL-33 to target numerous immune cell types, like Th2-like cells, mast cells and B1 cells, and to induce cytokine and chemokine production underlines its potential in influencing the outcome of a wide range of diseases, such as arthritis, asthma, atopic allergy & anaphylaxis, cardiovascular disease/atherosclerosis, nervous system diseases and sepsis. IL-33 facilitates Treg expansion in vitro and in vivo. Recently, IL-33 has been involved in adipocyte differentiation. The biological activity of IL-33 at its receptor ST2 is rapidly terminated in the extracellular environment by its oxidation (formation of two disulfide bridges), resulting in an extensive conformational change that disrupts the ST2 binding site. Mutations at amino acids C208S/C232S protect IL-33 from oxidation and increase its activity.

Supplier: STEMCELL Technologies

Leukemia inhibitory factor (LIF) is an interleukin 6 class cytokine that regulates a broad variety of developmental functions. After LIF binds to LIF receptor (LIFR), LIFR associates with gp130 and activates JAK/STAT and MAPK signaling (Auernhammer and Melmed; Suman et al.). LIFR activation of STAT3 is essential for maintaining the mouse embryonic stem cell phenotype (Niwa et al.). Produced by the endometrium, LIF plays an important autocrine and paracrine role in implantation by regulating proliferation, invasion, and differentiation of trophoblasts following blastocyst attachment (Auernhammer and Melmed; Suman et al.). Human LIF can be used for the maintenance of mouse embryonic stem cells, however mouse LIF cannot bind to the human receptor, thus rendering mouse LIF inactive (Dahéron et al.). LIF is produced by CD4+ and activated regulatory T cells, and promotes Foxp3 expression, while repressing Th17 lineage-specific genes (Metcalfe). LIF is also secreted by mesenchymal stromal cells, where it supports hematopoiesis and immune modulation (Nasef et al.).

Supplier: STEMCELL Technologies

CD40 ligand is a type II transmembrane glycoprotein that belongs to the tumor necrosis factor (TNF) superfamily (Quezada et al.). CD40 ligand forms a bioactive homotrimer that exists as both soluble and membrane-bound forms (Khandekar et al.). CD40 ligand is expressed on T cells, monocytes, basophils, eosinophils, platelets, dendritic cells, and endothelial cells. Its receptor, CD40, is expressed on B cells, dendritic cells, macrophages, monocytes, platelets, endothelial cells, and epithelial cells (van Kooten and Banchereau). Binding of CD40 ligand to CD40 stimulates B cell proliferation, immunoglobulin class switching, antibody secretion, and T cell-dependent humoral responses. Dysregulation of CD40 ligand contributes to immune deficiency in HIV and AIDS (Rickert et al.). CD40 ligand has also been linked to the pathology of atherosclerosis, atherothrombosis, and restenosis (Hassan et al.).

Supplier: STEMCELL Technologies

Fractalkine (CX3CL1) is a unique chemokine belonging to the CX3C family, and is characterized by a C-X3-C cysteine motif within the chemokine domain, near the amino terminus of the protein (Bazan et al.). The chemokine domain is connected to an extended mucin-like stalk, followed by a transmembrane region, and a C-terminal intracellular domain (Imai et al.; Jones et al.). The protein signals through interaction with a single receptor, CX3CR1, expressed on monocytes, natural killer cells, T cells, microglia, and smooth muscle cells. Fractalkine is upregulated in endothelial cells by inflammatory signals and is synthesized as a membrane-bound molecule that mediates cell migration and adhesion (White and Greaves). Cleavage at the base of the stalk by metalloproteinases generates a soluble chemokine, which functions as a potent chemoattractant of target cells (Garton et al.; Apostolakis and Spandidos). Fractalkine has been implicated in pathology of inflammatory diseases, such as atherosclerosis and other vascular diseases, and has anti-apoptotic functions (White and Greaves).

Supplier: BioVendor

Alpha 1-microglobulin (A1M) is a lipocalin superfamily member (kernal lipocalins). A1M is a low molecular weight protein component of plasma. A1M is distributed in plasma and extravascular compartments of all organs. Alpha-1 Microglobulin is found in mammals, birds, amphibians and fish. The primary sites of A1M synthesis are the liver and the kidney. Around the opening of the lipocalin pocket three lysyl residues are situated; those residues carry yellow-brown modification derived from the binding and degradation of heme and kynurenin (a tryptophan metabolite). A1-Microglobulin’s reductase and dehydrogenase have broad biological substrate specificity properties due to its’ free cysteine side-chain which is located in a flexible loop. Alpha-1-microglobulin is glycosylated by three separate carbohydrate chains: two complex carbohydrates which are N-linked to asparagines at residues 17 and 96, and the other simple carbohydrate which is O-linked to threonine at position 5. The carbohydrates comprise 22% of the total molecular mass of the protein. The glycosylation varies between species. A1M exists in two forms- a free form and complexed to other macromolecules: in humans- complexed to immunoglobulin A (IgA), in rat- complexed to alpha-1-inhibitor-3. Free A1M is exceptionally heterogeneous in charge (therefore also known as protein HC), and is found tightly linked to a chromophore. The free Alpha-1-microglobulin is a monomeric protein composed of one 188 residue polypeptide and contains three cysteines, two of which (residues 75 and 173) form a conserved intra-molecular disulphide link. The chromophoric group is covalently bound to the free cysteine residue at position 34. A1M binds retinol as a major ligand, but this is probably distinct from its covalent chromophore.

Supplier: STEMCELL Technologies

Interleukin 1 receptor antagonist (IL-1RA) is a member of the IL-1 family that binds to IL-1 receptors but does not induce any intracellular signaling (Arend et al.). IL-1RA is a natural regulator of IL-1’s biological activity. It binds to the IL-1 receptors with similar affinity as IL-1, thereby inhibiting the proinflammatory activities of IL-1ɑ and IL-1ꞵ (Kinne et al.). In particular, mesenchymal stem cells have been shown to enhance tissue repair in an IL-1RA-dependent manner through the suppression of IL-1ꞵ production in dermal macrophages and enhanced expansion of immunosuppressive regulatory T cells in the skin (Harrell et al.). IL-1RA has also been shown to help in the treatment of rheumatoid arthritis (Cutolo), sepsis, asthma (Mao et al.), and inflammatory bowel diseases (Dosh et al.). This product is animal component-free.

Supplier: Adipogen

Interleukin-27 (IL-27) is a heterodimeric group 2 receptor ligand molecule that belongs to the IL-6/IL-12 family of long type I cytokines. It is composed of EBI3 (EBV-induced gene 3), a 34 kDa glycoprotein that is related to the p40 subunit of IL-12 and IL-23, and p28, the cloned 28 kDa glycoprotein that is related to the p35 chain of IL-12. IL-27 is expressed by monocytes, endothelial cells and dendritic cells. IL-27 binds to and signals through a heterodimeric receptor complex composed of WSX1 (TCCR) and gp130. Evidence suggests IL-27 interacts only with WSX-1. IL-27 has both anti- and proinflammatory properties. As an antiinflammatory, IL-27 seems to induce a general negative feedback program that limits T and NK-T cell activity. At the onset of infection, IL-27 induces an IL-12 receptor on naïe CD4+ T cells, making them susceptible to subsequent IL-12 activity (and possible Th1 development). Notably, IL-12 family cytokines are both induced and inhibited by bacterial products. Microbes promote IL-27 secretion through TLR4, and also block IL-27 production via C5a induction.

Supplier: STEMCELL Technologies

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, bone formation and resorption (Sims and Quinn; Tanaka and Miyajima).

Supplier: STEMCELL Technologies

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.).