THE EFFECT OF INTERLEUKIN-2 AND TRANSFORMING GROWTH-FACTOR-BETA-2 (TGF-BETA-2) ON THE PROLIFERATION AND NATURAL-KILLER ACTIVITY OF DECIDUAL CD16(-) CD56(BRIGHT) NATURAL-KILLER-CELLS

The present study, using flow cytometry, demonstrated that CD16- CD56bright natural killer (NK) cells, which are abundant in the decidua, have both interleukin-2 receptor alpha (IL-2Rα) and interleukin-2 receptor beta (IL-2Rβ). The NK activity and DNA synthesis of CD16- CD56bright NK cells were markedly elevated even by treatment with small amounts of IL-2. These results indicate that decidual CS16- CD56bright NK cells possess a high-affinity receptor for IL-2. Transforming growth factor-β2 (TGF-β2), which is contained in the decidua and is thought to serve as a major immunosuppressive factor, reduced the NK activity of decidual CD16- CD56bright NK cells, but it hardly affected the IL-2-induced augmentation of the NK activity or DNA synthesis of decidual CD16- CD56bright NK cells. The conclusion has therefore been reached that once IL2 is produced in the decidua, the IL-2-induced potentiation of the NK activity of decidual CD16- CD56bright NK cells cannot be suppressed by TGF-β2. © 1993 Academic Press. All rights reserved.