Interleukin-2 production by cord blood lymphocytes stimulated with mitogen and in the mixed leukocyte culture.

We examined the ability of cord blood lymphocytes to produce interleukin-2 (T cell growth factor) in response to phytohemagglutinin and in the mixed leukocyte culture. Interleukin-2 production was measured by the proliferative response of an interleukin-2-dependent mouse T cell line to the addition of supernatant obtained from cord blood lymphocyte cultures. Using these assays we have shown that cord blood lymphocytes have a normal ability to produce interleukin-2 in both PHA-stimulated cultures and in the mixed leukocyte culture. The normal production of interleukin-2 by cord blood cells indicates, that newborn T lymphocytes are mature, and that a dissociation exists between their normal ability to produce interleukin-2 and their ability to produce other lymphokines, which was reported to be impaired. The reported deficiency of HLA-DR antigen expression on newborn monocytes does not seem to interfere with the production of interleukin-2 in the mixed leukocyte culture.