Fetal calf serum-induced blastogenic and cytotoxic responses of human lymphocytes.

Incubation of normal human peripheral blood lymphoid cells in fetal calf serum-supplemented media initiates blastogenic and nonspecific cytotoxic responses. A panel of lymphocytes from 13 normal donors exhibited increased [3H]thymidine incorporation from 2 to 40 times that of control lymphocytes incubated in pooled human AB-supplemented media. Fetal calf serum-sensitized human lymphoid cells were active in cytotoxicity assays against a wide variety of cultured human tumor and normal target cells. Cytotoxicity continued to increase from 3 to 9 days of incubation in fetal calf serum-supplemented media, while blastogenic response peaked at 6 days of incubation. Cytotoxic and blastogenic responses increased with higher concentrations of fetal calf serum. Once stimulated with fetal calf serum, the lymphocytes did not require the continued presence of fetal calf serum to mediate a cytotoxic reaction.