Differential expression of the interleukin 2 receptor β (p75) chain on human peripheral blood natural killer subsets

The interleukin-2 receptor (IL-2R) is composed of at least two subuntts, the IL-2Rα (P55, CD25/Tac) and IL-2Rβ (p70-75) chains. In the present study we have Identified the quantitative expression of IL-2Rβ on subsets of NK cells In peripheral blood using flow cytometry and a recently established mAb against IL-2Rβ (TU27). We demonstrate that NK cells are not a homogeneous population but that phenotypic subsets exist, and that the levels of IL-2Rβ expression correlate with these subsets. The levels of IL-2Rβ expression on NK subsets are CD3-CD16-CD56^bright NK cells (immature NK) > CD16⁺CD57^- NK cells (mature NK) > CD16 ⁺ CD57⁺ NK cells (more mature NK) in adult peripheral blood lymphocytes. The level of IL-2Rβ expression on CD16⁺ NK cells in cord blood Is significantly higher than that In adult PBL. These findings suggest that there may be a Inverse relationship between IL-2Rβ expression and the differentiation of NK cells. IL-2Rβ, preferentially expressed on the NK cells, may play an Important role In differentiation and maturation of NK cells.