AUGMENTATION OF NK CELL-ACTIVITY AND PROLIFERATION IN CULTURED LYMPHOCYTES OF LEUKEMIC PATIENTS BY MONOCLONAL-ANTIBODIES CD3 AND INTERLEUKIN-2

The aim of the present study was to induce NK tell activity in periphe ral mononuclear cells (PMNC) of normal individuals or of leukemic pati ents. For this purpose, monoclonal antibodies (mAbs) anti-CD3 (MEM 57, OKT 3 and MEM 92), anti-CD59 (MEM 43) and anti-CD43 (MEM 59) were tes ted MEM 43, MEM 59, MEM 57 and OKT 3 stimulated markedly the NK activi ty in fresh isolated PMNC of normal individuals, whereas the cytotoxic ity in 3-day cultivated PMNC was enhanced only by MEM 57 and OKT 3. In comparison to interleukin-2 (IL-2), MEM 57 and OKT 3 induced less PMN C cytotoxicity but more cell proliferation. MEM 92 (anti-CDS, IgM) com pared to MEM 57 or OKT 3 (anti-CD3, IgG) did not show any effect on bo th reactions mentioned above. PMNC of untreated Leukemic patients exer ted very negligible NK cell activity. Following 3-day culture of leuke mic PMNC with OKT 3 or IL-2 the anti-K 562 cytotoxicity was markedly e nhanced. In some cases the stimulating effect was more pronounced by I L-2, in others by OKT 3. Nevertheless, the best effect was gained in 7 out of 12 patients using a combination of IL-2 and OKT 3. On the othe r hand, OKT 3 did not synergize with IL-2 in normal PMNC culture,