Boster Pathways-> Immunology and Inflammation

Cytokine Network

The cytokine network is a collection of signaling molecules that mediate and regulate immunity, inflammation, hematopoiesis, and a variety of other cellular processes.

Overview of Cytokine Signaling pathway

Cytokine refers to the proteins produced by cells in response to a variety of inducing stimuli; they are secreted by their produce cells and then influence the behavior of target cells.the nature of the target cell for a particular cytokine is determined by the presence of specific receptors. They may be present on the surface of the same cell as produces the cytokine, in which case autocrine effects are possible.cytokine may work only on other cell types which are not themselves producers.of this target cells lie close by the producer cells,the term 'paracrine regulation' is used to describe the process. Cytokines are a very diverse group of members with a variety of effects,but most share certain structural and functional features.

Other names are assigned to cytokines based on their hypothesized function, secretion cell, or target of action. For example, lymphokines are cytokines produced by lymphocytes, but interleukins are produced by one leukocyte and act on other leukocytes. Chemokines, on the other hand, are cytokines having chemotactic properties. Cytokines have the ability to act on the cells that release them (autocrine action), neighboring cells (paracrine action), and, in some cases, distant cells (paracrine action) (endocrine action).

History of Cytokine Signaling pathway

Soluble factors as lymphocyte function regulators were not explored until the mid-1970s, when Igal Gery and Byron Waksman first described "lymphocyte activating factor," which was later renamed "T cell growth factor." Before the emergence of receptors and signaling cascades, cytokines emerged from their primordial forms as intracellular molecules. Invertebrates such as starfish and Drosophilia have been shown to exhibit cytokine-like actions, and they play an important role in host defense and healing.

The Cytokine Network

Everything you need to know about the cytokine network

Cytokine families

Interleukins, chemokines, colony-stimulating factors (CSF), interferons, and the transforming growth factor (TNF) and tumor necrosis factor (TGF) families are all members of the cytokine superfamily, which includes interleukins, chemokines, colony-stimulating factors (CSF), interferons, and the transforming growth factor (TNF) and tumor necrosis factor (TGF) families. Cytokines are classified into large families that are structurally similar but have a wide range of cytokine activities.

In their reciprocal receptor networks, cytokine families share sequence similarity, homology, and some promiscuity. They don't have anything in common in terms of functionality. Important regulating cell membrane receptor-ligand combinations are also found in cytokine families, indicating evolutionary pressures that utilise shared structural motifs in various immunological activities in higher animals. Immune-regulatory cytokines, such as TNF-, lymphotoxins, and cellular ligands, such as CD40L, which facilitates B cell and T cell activation, and FasL (CD95), which promotes apoptosis, are all members of the TNF/TNF receptor superfamily.

Similarly, the IL-1/IL-1 receptor superfamily contains cytokines that mediate physiologic and host-defense function, such as IL-1, IL-1, IL-receptor antagonist, IL-18, and IL-33, but it also includes the Toll-like receptors, a group of mammalian pattern-recognition molecules that play a critical role in recognizing microbial species early in innate responses.

Cytokine Signaling

The human body's control relies heavily on cytokine signaling. The majority of cytokines are intracellular signaling proteins released by glial cells in the brain system. The majority of cytokines serve as local regulators, alerting and activating lymphocytes. Hormones like growth hormones and leptin, the fat-storage hormone, are involved in several cytokine-signaling pathways.

To keep the human body healthy, the immune system relies on cytokine signaling. Foreign particles are engulfed by macrophages and dendritic cells, which then deliver a cytokine signal to surrounding dormant lymphocytes. The lymphocytes' receptors recognize the signal and activate. These cells have been programmed to identify specific antigens. The combination of macrophages and lymphocyte activation via cytokine signaling helps the body maintain homeostasis, or proper internal balance.

Some cytokine signals go a significant distance throughout the body rather than being localized. Some of these cytokines are categorized as hormones.

However, because cytokines are not released by glands, this categorisation is evolving. Instead, they are secreted by nervous system glial cells. These growth hormones are necessary for the development of the embryo. Cytokines bind to receptors on target cells, triggering an intercellular signaling cascade. The protein kinase transduction cascade is the most prevalent of these pathways. Inactive protein kinases are activated by a process known as phosphorylation once the cytokine binds to the receptor anchored in the cell membrane.

Function of Cytokines

Cytokines are tiny glycoproteins that regulate immunity, inflammation, and hematopoiesis and are produced by a variety of cell types, primarily leukocytes. They control a variety of physiological and pathological functions, including innate and acquired immunity, as well as a variety of inflammatory responses. The discovery of cytokines began in the 1950s, but it required several years to fully understand their structure and function. IL-I, IFN, and nerve growth factors (NGFs) were discovered first, but it took years for these cytokines to be isolated and given names. The specific physiological, clinical, and pharmacological consequences of certain cytokines are currently being investigated.

Modern molecular biology techniques were primarily responsible for their entire identification, and as a result, hundreds of cytokine proteins and genes have been identified, with the process continuing. Cytokines regulate immunological and inflammatory responses and are produced by a variety of sources during the effector phases of natural and acquired immune responses. They are also secreted during non-immune events and perform a role in numerous tissues that is unrelated to the immunological response. Their secretion is usually a one-time, self-contained event. They are produced by a wide range of cell types and act on a wide range of cell types and tissues. Cytokines can have various actions on the same target cell, and they can also stimulate or inhibit the production and effects of other cytokines.

Cytokines have distinct effects after attaching to specific receptors on the cell surface of target cells. The expression of cytokine receptors is controlled by a variety of signals. The target cells respond to cytokines by synthesising new mRNA and proteins, resulting in a distinct biological response. They function through receptors and are particularly important in the immune system; cytokines govern the maturation, development, and responsiveness of specific cell types, as well as the balance between humoral and cell-based immune responses. In intricate ways, certain cytokines boost or inhibit the function of other cytokines.