CD25, the low-affinity IL-2 Receptor ? chain (IL-2R?, p55) expressed on activated T and B lymph ocytes from all mouse strains tested. IL-2R? by itself is not a signaling receptor. However, it can combine with IL-2 Receptor ? (CD122) and ?c (CD132) chains to form high-affinity, signaling receptor complexes for IL-2. Resting T and B lymph ocytes and resting and activated NK cells do not express IL-2R?. CD25 is transiently expressed at a low level during normal B-cell development in the bone marrow on the CD45R/B220low TdT- sIg- Pre-B/Pre-B-II and CD45R/B220low TdT- sIgM+ sIgD- immature B stages, but not on the CD45R/B220low TdT+ sIg- Pro-B/Pre-B-I stage nor on CD45R/B220high TdT- sIgM+ sIgD+ mature B cells. It is expressed at a higher level during a very early stage of T-cell development in fetal and ***** thymus. Peripheral CD25+CD4+ lymph ocytes called regulatory T (Treg) cells are involved in the maintenance of self-tolerance. It has also been reported that dendritic cells express CD25, recognized by mAb 7D4. The PC61 antibody recognizes an epitope of CD25 which is distinct from the IL-2 and from those recognized by mAbs 3C7 and 7D4. It blocks binding of IL-2 to CD25, presumably by inducing a conformational change in CD25.
-
Interleukin-2 receptor alpha chain; IL-2RA; IL-2R?; Il2ra; IL-2R p66
-
-
55 kD