Specific cytokines & growth factors in… hematology!

Hematology is the study of blood, blood-forming organs and blood diseases. The formation of blood cells is referred to as hematopoiesis. All cellular components of the blood are derived from hematopoietic stem cells.

Blutkörperchen in einer ArterieHematopoietic stem cells (HSCs) are located in the red bone marrow and during proliferation, at least a few daughter cells remain HSCs, meaning that the pool of HSCs does not become depleted.
However, other daughter cells undergo differentiation processes which result in the production of specialized blood cells.

Several growth factors and cytokines play a crucial role in these differentiation processes:

Erythrocytes:

Erythropoiesis is the development process by which new erythrocytes are produced. Some growth factors have already been determined as negative or positive regulators.

  • SCF (Stem Cell Factor): a cytokine that exerts its activity by signaling through the c-Kit receptor
  • EPO (Erythropoeitin): a main regulating factor for erythropoiesis
  • GM-CSF (Granulocyte/Macrophage Colony-Stimulating Factor): a hematopoietic growth factor that stimulates the development of neutrophils and macrophages and promotes the proliferation and development of early erythroid megakaryocytic and eosinophilic progenitor cells
  • IL-3 (Interleukin-3): a cytokin that can improve the body’s natural response to disease as part of the immune system

Megakaryocytes:

The development of megakaryocytes is a cellular process with multiple stages, controlled positively by numerous cytokines.

  • TPO (Thrombopoietin): a lineage specific growth factor, produced in the liver, kidney and skeletal muscle that stimulates the proliferation and maturation of megakaryocytes, and promotes increased circulating levels of platelets in vivo.
  • SCF (Stem Cell Factor): a cytokine that exerts its activity by signaling through the c-Kit receptor
  • IL-6 (Interleukin-6): a pleiotropic cytokine that plays an important role in host defense by regulating immune and inflammatory responses
  • IL-11 (Interleukin-6): a multifunctional cytokine produced by stromal cells such as fibroblasts, epithelial cells and osteoclasts

Monocytes:

Monocytes are leukocytes of the agranulocytes family, which evolve in macrophages or dentritic cells or osteoclasts.

  • GM-CSF
  • M-CSF (Macrophage Colony Stimulating Factor): a potent hematopoietic factor which plays a key regulator role of cellular proliferation, differentiation, and survival of blood monocytes, tissue macrophages and their progenitor cells

Neutrophilic granulocytes:

Neutrophilic granulocytes are phagocytes, which are cells able to swallow and digest antigens such as bacteria.

  • GM-CSF (Granulocyte/Macrophage Colony-Stimulating Factor): a hematopoietic growth factor that stimulates the development of neutrophils and macrophages and promotes the proliferation and development of early erythroid megakaryocytic and eosinophilic progenitor cells
  • G-CSF (Granulocyte Colony-Stimulating Factor): a hematopoietic growth factor that stimulates the development of committed progenitor cells to neutrophils and enhances the functional activities of the mature end-cell

Basophilic granulocytes:

Basophilic granulocytes attract other white blood cells and release histamin contained in their granulates. This histamine activates the inflammatory reaction and  intervenes in the allergic reactions.

  • IL-3
  • IL-4: a pleiotropic cytokine that regulates diverse T and B cell responses including cell proliferation, survival and gene expression
  • SCF

Eosinophilic granulocytes:

Eosinophilic granulocytes secrete substances which tend to limit the action of the histamine of basipholic granulocytes . Their role is to attack body’s parasites without absorbing them. They fix above them and mobilise their granulates which contain enzymes intended to destroy them.

  •  GM-CSF
  • IL-3
  • IL-5: a hematopoietic growth factor that stimulates the proliferation and activation of eosinophils. Produced by mast cells, T cells, and eosinophils, IL-5 plays an important role in inducing cell-mediated immunity against parasitic infections and certain tumors

 Any doubts about the best factors for your research?

There’s a vast offer of cytokines available, finding the right ones (and the best quality ones) can be made easier by calling in some expert advice. tebu-bio’s teams are always happy to answer any questions and offer advice.

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  1. […] If you’re interested in other hematopoietic factors, you might like to take a look at our recent post on Specific cytokines & growth factors in… hematology […]

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