Modulation of the interleukin 2 receptor by maternal and cord blood serum.

In this report, the potential inhibitive action, of maternal serum (retroplacental and peripheral), and cord blood serum on the expression of the Il2r has been studied. Calf and male serum were used as a control. In order to have an optimal Il2r expression, a previous PHA cellular stimulation was performed. The maternal serum's Il2r inhibitive property was measured during and after the pregnant period. The presence of Il2r on maternal lymphocytes, cord blood cells, and unrelated donor mononuclear cells has been investigated (after a PHA stimulation assay). The downregulated Il2r expression of neoplastic cell line (Hut78 cell line) under the influence of maternal serum has been observed. The examination of the inhibitive action due to maternal serum has suggested that a factor included in the IgG fraction is mainly responsible for the downregulating property concerning the Il2r expression. A possible mechanism for the action of this factor has been studied. Further experiments suggest that the addition of recombinant Il2 during the action of low doses of maternal IgG allows a partial reexpression of the Il2 receptor. However, at physiological concentrations of IgG, the Interleukin 2 receptor downregulation becomes irreversible.