The aim of this study was to compare the alloreactive responses against HLA antigens of cord blood cells with those of adult peripheral blood cells. In primary mixed lymphocyte Cultures and bulk cell-mediated lympholysis experiments cord blood cells demonstrated significantly decreased proliferation and cytotoxicity.
Experiments analyzing the specificity of anti-HLA cytotoxic T lymphocytes (CTL) revealed that cord blood (CB) CTL reacted only partially with third-party cells expressing the stimulating HLA antigens. Lower frequencies of IL-2 producing helper, cytotoxic T-cell precursors and IL-4 producing CB cells were found, whereas the frequencies of IFN-gamma producing cells, as determined by ELISpot experiments, were equivalent to the frequencies of adult IFN-gamma producing cells.
Our results imply that, although CB cells have significantly decreased proliferative and cytotoxic alloresponses in bulk mixed lymphocyte cultures, their IFN-gamma production is comparable with that of adult mononuclear cells. Preserved production of IFN-gamma may be a risk factor for the development of graft-versus-host disease and should be taken into consideration when evaluating the possibility for stem cell transplantation with HLA-mismatched CB.
Human lmmunology 63, 155-163 (2002). (C) American Society for Histocompatibility and Immunogenetics, 2002. Published by Elsevier Science Inc.