CD25
CD25 is the alpha chain of the IL-2 receptor.[1] It is a type I transmembrane protein present on activated T cells, activated B cells, some thymocytes, myeloid precursors, and oligodendrocytes that associates with CD122 to form a heterodimer that can act as a high-affinity receptor for IL-2. Though CD25 has been used as a marker to identify CD4+FoxP3+ regulatory T cells in mice, it has been found that a large proportion of resting memory T cells constitutively express CD25 in humans.[2]
CD25 is expressed in most B-cell neoplasms, some acute nonlymphocytic leukemias, neuroblastomas, mastocytosis and tumor infiltrating lymphocytes. It functions as the receptor for HTLV-1 and is consequently expressed on neoplastic cells in adult T cell lymphoma/leukemia. Its soluble form, called sIL-2R may be elevated in these diseases and is occasionally used to track disease progression.
Notes and references
- ^ Janeway CA Jr, Travers P, Walport M, et al. Immunobiology: The Immune System in Health and Disease. 5th edition. New York: Garland Science; 2001. Available from: http://www.ncbi.nlm.nih.gov/books/NBK10772/
- ^ Triplett, Todd A.; et al. (July 2012). "Defining a functionally distinct subset of human memory CD4+ T cells that are CD25POS and FOXP3NEG". European Journal of Immunology. 42 (7): 1893. doi:10.1002/eji.201242444.