antiCD25

Anti-CD25 refers to monoclonal antibodies that bind to CD25, the alpha chain of the interleukin-2 receptor (IL-2Rα). CD25 is expressed on activated T cells and regulatory T cells, and is part of the high-affinity IL-2 receptor complex together with CD122 (IL-2Rβ) and the common gamma chain. By targeting CD25, anti-CD25 antibodies can modulate T cell activation and proliferation, either by blocking IL-2 signaling or by depleting CD25-expressing cells through immune effector mechanisms such as antibody-dependent cellular cytotoxicity.

Mechanisms of action vary by antibody. Some anti-CD25 agents are antagonistic, blocking IL-2 binding and signaling to prevent T cell activation. Others are depleting antibodies that reduce the number of CD25-positive cells. The chosen mechanism influences therapeutic use and safety profiles, particularly concerning effects on regulatory T cells, which constitutively express CD25 and help maintain immune tolerance.

Clinical use has been most prominent in transplantation and certain autoimmune diseases. Basiliximab is a chimeric anti-CD25 antibody used to prevent acute rejection in kidney transplantation, typically given around the time of surgery. Daclizumab, a humanized anti-CD25 antibody, was investigated for transplant prophylaxis and for autoimmune diseases such as multiple sclerosis; it was withdrawn from the market due to safety concerns, including inflammatory brain disorders. Other anti-CD25 antibodies have been explored mainly in research settings, including strategies to modulate regulatory T cells in cancer and autoimmunity.

Safety considerations center on increased infection risk and effects on regulatory T cell function. The safety and therapeutic profile depend on the specific antibody, dosing regimen, and patient population.