Granulocyte Colony Stimulating Factor (G-CSF) is a naturally occurring protein hormone that regulates the production and maturation of certain white blood cells called granulocytes in the bone marrow. It belongs to a category of signals called cytokines, which play a crucial role in the immune system and hematopoiesis (blood cell formation).
G-CSF is produced and released by various cells in the body, including macrophages, fibroblasts, and endothelial cells, in response to certain conditions such as infection, injury, or low levels of granulocytes. Once released, G-CSF binds to specific receptors on the surface of hematopoietic stem cells in the bone marrow, stimulating their differentiation and proliferation into mature and functional granulocytes.
Granulocytes, which include neutrophils, eosinophils, and basophils, are an integral part of the immune system's defense mechanism against various microorganisms, such as bacteria and fungi. G-CSF stimulates the production and release of these cells into the bloodstream, where they can migrate to sites of infection or inflammation to eliminate pathogens or restore tissue homeostasis.
In medicine, recombinant human G-CSF is used as a therapeutic agent to boost the production and function of granulocytes in individuals with suppressed immune systems, such as those undergoing chemotherapy or hematopoietic stem cell transplantation. It can help reduce the duration and intensity of neutropenia (a condition characterized by low levels of neutrophils) and the risk of infections associated with compromised immunity.
