Bone marrow and peripheral blood natural killer cell activity in lymphomas. Its response to IL-2

Abstract

Natural killer (NK) cytotoxic activity was simultaneously investigated in bone marrow mononuclear cells (BMMC) and peripheral blood lymphocytes (PBL) from nine Hodgkin's disease (HD) and 15 non-Hodgkin lymphoma (NHL) untreated patients. Twenty-five PBL samples and seven bonemarrow specimens from healthy individuals were also included as control group (C). NK cell activity was evaluated in basal condition and post-stimulation with human recombinant IL-2 (rIL-2). Data were expressed in Kvalues (number ofBMMC or PBL needed to lyse 50% of the target cells). In basal condition, both HD and NHL patients showed a NK cell activity comparable to the C group, both in BMMC (HD, K=248+13; NHL, K= 38+220; C, K= 3 2+0 7) and PBL (HD, K= 2-0+I-0; NHL, K= 2-3 + I 0; C, K=2 2 + 0 2). Stimulation with rIL-2 induced a significant and comparable enhancement of the NK activity in PBL from HD, NHL and C while the response to rIL-2 of the BMMC in most of the HD and NHL patients was significantly greater than the C group. Responder cells were characterized by negative selection with specific MoAb plus complement as a CD3-, CD16+, CD56+ cytotoxic cell and further confirmed by flow cytometry. We postulate that IL-2 activation of bone marrow NK cell precursors, in addition to enhancing the activity of circulating NK, may be df value for the therapeutic rationale of IL-2 in patients with lymphoma.