The production of soluble and cellular interleukin-2 receptors by cord blood mononuclear cells following in vitro activation.

Cord blood mononuclear cells (CBMC) were investigated for their capacity to generate both cellular and soluble, supernatant interleukin-2 receptors (IL-2R) following cellular activation in vitro. Soluble IL-2R were measured in cell-free supernatants and in detergent-solubilized cell extracts with a "sandwich" enzyme-linked immunosorbent assay. CBMC and adult peripheral blood mononuclear cells were activated with phytohemagglutinin or the murine monoclonal antibody OKT3. CBMC and adult peripheral blood mononuclear cells generated cellular and soluble IL-2R in response to both activators. Peak values for supernatant IL-2R were observed on day 7, while peak values of cell-associated IL-2R occurred on day 5, followed by a decline on day 7. With the exception of supernatant IL-2R production induced by OKT3 stimulation, CBMC produced IL-2R in amounts comparable to adult mononuclear cells. Cord blood plasma also contained amounts of IL-2R comparable to that found in adult sera/plasma. Thus, CBMC appear largely immunocompetent with regard to the expression of IL-2R.