Cytokine proteins

What are cytokines ?

Cytokines are proteins involved in cell communication and interaction. These proteins are not able to cross the lipid bilayer and enter the cytoplasm but are transported via cell vesicle before going to the corresponding organelle. Cytokines can act on the same cell that secreted them (autocrine), they can act on the cell in close proximity to the one that secreted them (paracrine) or they can act as hormones (endocrine). They may act as immunomodulating agents. These proteins are produced by many cell types, but the predominant producer cells are macrophages and helper T cells. More precisely, T help 2 cells which produces various cytokines that provide phagocyte-independent protective response. There are many types of cytokines based on the cell that secretes them. Monokine (cytokines made by monocytes), lymphokine (cytokines made by lymphocytes, chemokine (cytokines with chemotactic activities), and interleukin (cytokines made by one leukocyte and acting on other leukocytes) all belong to cytokine group of proteins. Different cell type may secrete the same cytokine and a single cytokine may influence different cells. These proteins are produced in a cascade. They can be both pro-inflammatory and anti-inflammatory. For instance, TNF and interleukin 1 (IL-1) are proinflammatory cytokines. Cytokines activity is not limited to modulating immune response. In the peripheral nerve tissues, Schwan cells, endothelial cells and immune cells may secrete these proteins along with growth factors and other molecules to help with nerve regeneration. Cytokines can have profound effects on neuronal activity and are believed to be involved in various pathological pain states.

Common features of cytokine proteins

Cytokines are secreted from the cell following an external stimulus. The messenger RNA that encoded is unstable and causes a transient synthesis. As a result, these proteins are secreted once synthetized. As a result, the production of cytokines may be a self-limited process. Once secreted they are involved in up or down regulation of regulatory mechanisms. For instance, cytokines stimulate switching of antibody isotypes in B cells, differentiation of helper T cells into Th-1 and Th-2 subsets, and activation of microbicidal mechanisms in phagocytes. Cytokine production may stimulate or inhibit the production of other cytokines. One cytokine can have many functions and several cytokines may have same or similar functions. The combined effect of two cytokines on cellular activity is greater than the additive effects of individual cytokines. As a result of these properties, cytokines can regulate cellular activity in a coordinated interactive way. Cytokines have a high affinity for their receptor. As a result, only small quantities of a cytokine proteins are needed to occupy receptors and elicit biologic effects.

Clinical applications of cytokines

Cytokines are proteins, peptides or glycoproteins secreted by lymphocytes and monocytes that regulate immune responses, haematopoiesis and lymphocyte development. As such they are involved in numerous biological processes. Antibody-based techniques have developed to measure cytokine levels in circulation in health and disease. Such techniques include enzyme-linked immunosorbent assays and multianalyte bead systems. Cytokines represent messages between immune systems and cells. As such they can provide valuable insight in immune-related disease diagnosis, prognosis, and potential therapeutic avenues. Cytokines include chemokins, interleukins and other signaling molecules. ProteoGenix provides a wide range of high quality cytokine protein subtypes as well as:

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