Interleukin 3

Interleukin 3, also known as IL-3, is a is_associated_with::protein that in humans is encoded by the IL3 is_associated_with::gene.

Function
Interleukin-3 (IL-3) is an is_associated_with::interleukin, a type of biological signal (is_associated_with::cytokine) that can improve the body's natural response to disease as part of the immune system. It acts by binding to the is_associated_with::interleukin-3 receptor.

IL-3 stimulates the differentiation of is_associated_with::multipotent hematopoietic stem cells into is_associated_with::myeloid progenitor cells or, with the addition of IL-7, into is_associated_with::lymphoid progenitor cells. In addition, IL-3 stimulates proliferation of all cells in the myeloid lineage (is_associated_with::granulocytes, is_associated_with::monocytes, and is_associated_with::dendritic cells), in conjunction with other cytokines, e.g., is_associated_with::Erythropoietin (EPO), is_associated_with::Granulocyte macrophage colony-stimulating factor (GM-CSF), and IL-6. It is secreted by basophils and activated is_associated_with::T cells to support growth and differentiation of T cells from the bone marrow in an immune response. Activated is_associated_with::T cells can either induce their own proliferation and differentiation (is_associated_with::autocrine signalling), or that of other is_associated_with::T cells (is_associated_with::paracrine signalling) - both involve IL-2 binding to the IL-2 receptor on is_associated_with::T cells (upregulated upon cell activation, under the induction of is_associated_with::macrophage-secreted IL-1). The human IL-3 gene encodes a protein 152 amino acids long, and the naturally occurring IL-3 is glycosylated. The human IL-3 gene is located on chromosome 5, only 9 kilobases from the is_associated_with::GM-CSF gene, and its function is quite similar to GM-CSF.

Discovery
Interleukin-3 originally was discovered by JN Ihle in mice. He found a T cell derived factor that induced the synthesis of 20alpha-hydroxysteroid dehydrogenase in hematopoietic cells and termed it interleukin-3.

Interactions
Interleukin 3 has been shown to interact with is_associated_with::IL3RA.