Interleukin-2 receptor-α (IL-2Rα) on antigen-presenting dendritic cells (DCs) is now shown to trans-present IL-2 to T cells during the earliest stages of T cell activation (604–609). The resulting T cell proliferation is blocked by daclizumab, an IL-2Rα–specific antibody used to treat multiple sclerosis and prevent transplant rejection, highlighting the importance of understanding individual variability in immune responses to daclizumab treatment.
