Reviewer: S. Randhawa, M.D., Fellow, LSU (Shreveport) Department of Allergy & Immunology
CD127 is the IL-7 receptor alpha chain.
Interleukin 7 (IL-7)
Interleukin 7 (IL-7) is a hematopoietic growth factor secreted by the stromal cells of the bone marrow and thymus. IL-7 stimulates the differentiation of multipotent (pluripotent) hematopoietic stem cells into lymphoid progenitor cells (as opposed to myeloid progenitor cells where differentiation is stimulated by IL-3). IL-7 stimulates proliferation of all cells in the lymphoid lineage (B and T lymphocytes and NK cells). A defect in IL-7RA leads to SCID (T-/B+/NK+).
Interleukin-7 receptor (IL7R)
Interleukin 7 receptor (IL7R), also known as CD127 (Cluster of Differentiation 127), is a type I cytokine receptor. Type I cytokine receptors are transmembrane receptors expressed on the surface of cells that recognize and respond to cytokines with four α-helical strands.
Type I cytokine receptors are mediated through JAK/STAT and bind: IL-2, 3, 4, 5, 6, 7, 9, 10, 12, 13, 15, GM-CSF.
Key steps of the JAK-STAT pathway. Image source: Wikpedia, public domain.
Cytokine Signaling. This video is from: Janeway's Immunobiology, 7th Edition Murphy, Travers, & Walport. Source: Garland Science.
IL7R plays a critical role in the V(D)J recombination during lymphocyte development. A defect in IL-7RA leads to SCID (T-/B+/NK+).
Thymic stromal lymphopoietin (TSLP)
Thymic stromal lymphopoietin (TSLP) signals through a heterodimeric receptor complex composed of the TSLP receptor and the IL-7R alpha chain. Some researchers have classified TSLP as a "master regulator" of the Th2 response due to overexpression of the cytokine in pulmonary tissue and skin cells result in Th2-induced asthma and dermatitis.
TSLP is produced mainly by non-hematopoietic cells as fibroblasts, epithelial cells and different types of stromal cells.
Anti-TSLP is a potential new therapeutic target in asthma.
Receptors for IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21 contain γ chain, which is affected in X-linked SCID.
(click to enlarge the image)
Severe combined immunodeficiency (SCID) - 4 groups according to T/B/NK cells (click to enlarge the image).
Lack of a signal through which cytokine receptor accounts for the lack of T cell maturation in X-linked SCID?
Cluster of differentiation, Wikipedia.
List of human clusters of differentiation (CD), Wikipedia.
TSLP calms inflammation. The Journal of Experimental Medicine, Vol. 206, No. 3, 493, 2009.
Interleukin-7 receptor, Wikipedia.
Interleukin 7, Wikipedia.
Cluster of differentiation (CD) of leukocytes
Thymic stromal lymphopoietin (TSLP) is associated with allergic rhinitis in children with asthmahttp://goo.gl/c0vzJ