There have been several reports that lymphocytes of human cord blood have poor func tional properties because of their immaturity and/or the presence of suppressor cells. We studied here the in vitro effects of thymopoietin pentapeptide (TP-5) and interleukin 2 (IL-2) on cord blood T cells. Lymphocyte subsets were analyzed by flow cytometry thro ugh the use of monoclonal antibodies after a 48 h culture period in TP-5 (optimal dose ; 1 pg/ml) and/or IL-2 (non-mitogenic dose used ; 1% vol/vol).

more »

... T 8-positive cells were significantly decreased after treatment in combination with TP-5 and IL-2. But there were no changes in the propotion of OKT 3-, T4-, T11 and lal-positive cells. Poor helper activity of cord blood T cells, which was examined by enhancing activity of immunoglo bulin-production of normal adult non-T cells stimulated by pokeweed mitogen, was enha nced to a significant level of IgG production after treatment in combination with two agents. Crude IL-2 activity was reevaluated through the use of recombinant IL-2.