GSE52502
Two functionally distinct subsets of mast cells generated through IL-2 independent CD25 activities
CD25 (IL-2R) can be expressed on the surface of immune cells in the absence of other chains of the interleukin-2 receptor (IL-2R), which are indispensable for IL-2 signaling. We identified two novel mast cell subsets, characterized by the differential expression of surface CD25, and by the ability to produce different cytokines and to proliferate, both in vitro and in vivo. We provide evidence that functional differences between the two mast cell populations were dependent on CD25 itself, which directly modulated mast cell proliferation and responses in vivo. These effects were completely independent from IL-2 or the expression of the other chains of the high-affinity IL-2R, indicating an autonomous and previously unappreciated role for CD25 in regulating cell functions. Similar results were also obtained in dendritic cells, which are known to express CD25 but to be unresponsive to IL-2. Our findings indicate a general role for CD25 in contexts where IL-2 signaling is not involved, and may have important implications for all mast cell-related diseases, including mastocytosis, where CD25 is aberrantly expressed on pathogenic mast cells. Overall design: Total mRNA of FACS-sorted CD25pos and CD25neg populations of primary bone marrow-derived mast cells (BMMCs) was extracted and subjected to by multiparallel sequencing.