citokinés

Citokines are a broad and loose category of small proteins important in cell signaling. They are released by cells and affect the behavior of other cells. Citokines are involved in a wide range of physiological processes, including immunity, inflammation, and hematopoiesis. They can be produced by various cell types, such as immune cells, endothelial cells, and fibroblasts.

There are many different types of cytokines, and they are often classified based on their function or structure. Some examples include interleukins, interferons, tumor necrosis factors, and chemokines. Interleukins are a diverse group of cytokines that play a critical role in regulating immune responses. Interferons are primarily known for their antiviral properties, while tumor necrosis factors are involved in inflammation and apoptosis. Chemokines are a specific group of cytokines that attract cells to a particular site.

Citokines act by binding to specific receptors on the surface of target cells, triggering intracellular signaling pathways. This binding can lead to a variety of cellular responses, such as proliferation, differentiation, or the production of other signaling molecules. The effects of cytokines can be pleiotropic, meaning a single cytokine can have multiple effects on different cell types, or redundant, where multiple cytokines can have similar effects. Their actions are tightly regulated to maintain homeostasis and prevent excessive or insufficient responses. Dysregulation of cytokine signaling is implicated in various diseases, including autoimmune disorders, cancer, and infectious diseases.