36745 Results for: "Stream Tables Earth Science Models&amp"

BAFF is mainly produced by innate immune cells such as neutrophils, monocytes, macrophages, dendritic cells, follicular dendritic cells. T cells, activated B cells, some malignant B cells and also non-lymphoid cells like astrocytes, synoviocytes and epithelial cells can also produce BAFF. BAFF binds three distinct receptors (BAFF-R, TACI and BCMA) expressed predominantly on B cells, although activated T cells also express BAFF-R. BAFF is a master regulator of peripheral B cell survival, and together with IL-6, promotes Ig class-switching and plasma cell differentiation. Besides its major role in B cell biology, BAFF co-stimulates activated T cells. Deregulated expression of BAFF leads to autoimmune disorders in mice. In humans, elevated levels of soluble BAFF have been detected in the serum of patients with various autoimmune diseases such as Sjoegren syndrome, Rheumatoid arthritis (RA), Multiple sclerosis (MS) and Systemic Lupus Erythematosus (SLE). BAFF has also increased levels in some lymphoid cancers. Processed human BAFF can either remain as a trimer, which is usual for TNF family ligands or assemble into 60-mer composed of 20 trimers. Mouse BAFF 60-mer has been identified in the serum of BAFF transgenic mice. Oligomerization of BAFF 3-mer into 60-mer in human BAFF is prevented by mutation of His218, a residue critical for 3-mer-to-3-mer interactions, but not for receptor binding. Despite the predominant functional role of processed BAFF in vivo, membrane-bound BAFF might also play a role. Indeed, soluble BAFF (3-mer) can trigger BAFF-R but not TACI or BCMA, whereas oligomeric forms of BAFF (BAFF 60-mer), which mimic membrane-bound BAFF, activate all BAFF receptors.

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Human IL-2 (from HEK293 cells)

Supplier: Adipogen

Interleukin-2 (IL-2) is a 133 amino acid glycoprotein with one intramolecular disulfide bond and variable glycosylation. It is secreted by activated T cells and induces proliferation and maturation of activated T cells, natural killer cells and lymphokine activated killer cells. IL-2 also stimulates proliferation of antibody-producing B cells, activates neutrophils and induces mononuclear cells to secrete IFN-gamma and TNF-alpha and -beta. Moreover, studies have shown that IL-2 is required for activation-induced apoptosis, an important homeostatic mechanism in the immune system, which is involved in the maintenance of peripheral tolerance to self-antigens. IL-2 promotes T cell proliferation and particularly naive T cells. IL-2 signaling on activated T cells is effected through a quaternary high-affinity receptor complex consisting of IL-2, IL-2Ralpha (CD25), IL-2Rbeta and IL-2Rgamma. Naive T cells are relatively insensitive to IL-2 as they only express small amounts of IL-2Rbeta and IL-2Rgamma. They only acquire sensitivity after CD25 expression, which captures the cytokine and presents it to the IL-2Rbeta and IL-2Rgamma receptors. IL-2 Superkine (Fc) is an artificial variant of IL-2 containing mutations at positions L80F / R81D / L85V / I 86V / I92F. These mutations are located in the molecule's core that acts to stabilize the structure and to give it a receptor-binding conformation mimicking native IL-2 bound to CD25. These mutations effectively eliminate the functional requirement of IL-2 for CD25 expression and elicit proliferation of T cells. Compared to IL-2, the IL-2 superkine induces superior expansion of cytotoxic T cells, leading to improved antitumour responses in vivo, and elicits proportionally less toxicity by lowering the expansion of Tregulatory cells and reducing pulmonary oedema.