Diminished autologous mixed lymphocyte reaction in patients with Hodgkin disease: evidence for non-T cell dysfunction

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

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 bone marrow 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 K values (number of BMMC 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 = 2.48 +/- 1.3; NHL, K = 3.8 +/- 2.0; C, K = 3.2 +/- 0.7) and PBL (HD, K = 2.0 +/- 1.0; NHL, K = 2.3 +/- 1.0; 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 of value for the therapeutic rationale of IL-2 in patients with lymphoma.

Dysfunction of monocytes in Hodgkin's disease by excessive production of PGE-2 in long-term remission patients

The candidacidal activity and the production of oxygen radicals by monocytes were investigated in untreated and long-term remission patients with Hodgkin's disease (HD). Both groups showed a decreased candidacidal function of monocytes with a chemiluminescence (CL) response significantly lower and delayed with respect to normal controls. Indomethacin at 1 microgram/ml corrected the monocyte deficiency increasing the CL response to normal values and normalizing the kinetics in the untreated patients. However, in patients in remission, the peak was delayed and followed by a significant increase in the production of oxygen radicals compared with untreated patients. A direct linear correlation was found between the percentages of lysed Candida and maximum CL peak of stimulated monocytes. When prostaglandin E2 (PGE-2) levels, measured in supernatants of cultured mononuclear cells, were plotted against the percentages of killed Candida, an inverse linear correlation was found. Therefore, monocytes from HD patients have a dysfunction in the generation of oxygen radicals and a decreased candidacidal activity associated with excessive production of PGE-2. Indomethacin can correct the oxidative metabolism in the untreated patients while in apparently "cured" patients the disorder persists.

Peripheral blood lymphocyte response to recombinant and non-recombinant interleukin 2 in previously treated patients with Hodgkin's disease, long-time off-therapy

13 patients with Hodgkin's disease (HD) previously treated, 9 of whom were long-time (more than 2 yr) off-therapy, were studied for peripheral blood lymphocyte response to interleukin 2 and for lymphocyte subpopulations by means of in vitro cultures and monoclonal antibodies. The aim of the study was to ascertain the role played by interleukin 2 in the impaired cell-mediated immunity of HD patients. The results show a response of peripheral blood mononuclear cells of HD patients to either the T cell-specific polyclonal mitogens PHA and Con A or to the T cell-dependent, although B cell-specific, PWM, most significantly decreased compared to the normal response. As far as the interleukin 2 involvement in HD is concerned, our study suggests: an impaired endogenous interleukin 2 production by T lymphocytes, a most probable deficiency of the interleukin 2 receptor (Tac) expression and 3) a decrease of the number and/or of the function of NK cells no longer responsive in vitro to interleukin 2. The phenotypic analysis of peripheral blood mononuclear cells showed a slight decrease of total T cells (T3+), of the helper/inducer subset (T4+) and of the T4+/T8+ cells ratio. Our data seem to support the rationale for a therapeutical approach with interleukin 2 in controlled clinical trials also in HD patients, according to the experiments in progress in solid tumor patients.

Impaired interleukin regulation of the phytohemagglutinin response in Hodgkin's disease

Patients with active Hodgkin's disease (HD) often demonstrate an impaired T-cell proliferative response to phytohemagglutinin (PHA). The present study examined if interleukin regulation of the PHA response was defective in HD. The Hodgkin's PHA response was impaired at all concentrations of PHA utilized. Indomethacin increased the proliferative response but did not bring it to control levels. Stimulation of the cells with both PHA and irradiated Ia+ B cells normalized proliferation despite identical PGE2 concentrations as in the PHA alone cultures. Hodgkin's monocytes produced normal amounts of interleukin 1 (IL-1). Interleukin 2 (IL-2) production by Hodgkin's T cells was decreased in the PHA stimulated cultures, but was normal in the PHA and Ia+ cell stimulated cultures. In response to PHA stimulation alone, Hodgkin's T cells expressed less IL-2 receptor than control cells. The data suggest the diminished PHA response in HD is due to impaired IL-2 production resulting in diminished IL-2 receptor expression. However, when an Ia+ cell source is added to PHA as an additional stimulator, both TCGF production and proliferation are normalized. Monocytes serve to modulate the magnitude of the PHA response through production of both interleukin 1 and PGE2. However, in the presence of sufficient IL-2 production the influence of monocytes is minimized.

Association of HLA-DR antigens with the autologous mixed lymphocyte reaction

A study was performed to evaluate the association of HLA-DR antigens with the proliferative response of T cells in autologous mixed lymphocyte cultures. Peripheral blood mononuclear cells from 100 normal healthy individuals were typed for HLA-DR antigens and autologous mixed lymphocyte cultures were established. A low proliferative response from autologous cultures was found with individuals bearing HLA-DR3 antigens and in individuals with only one identifiable HLA-DR antigen. In contrast, a strong proliferative response was associated with HLA-DR6 and two identifiable HLA-DR antigens. These data are consistent with the hypothesis that HLA-DR3 antigens are associated with a weak immune response gene and HLA-DR6 antigens are associated with a strong immune response gene.

Monoclonal antibody analysis of responder and stimulator cells in the human autologous mixed lymphocyte reaction

Responder and stimulator cell subpopulations in the autologous mixed lymphocyte reaction (AMLR) were determined with the OK series of monoclonal antibodies. Mitomycin-C-treated, monocyte-enriched cell populations were used as stimulator cells in the AMLR. Treatment of these monocytes with either OKM and/or OKI monoclonal antibodies and complement resulted in a marked loss of ability of these cells to act as stimulators in the AMLR. Removal of OKT3+ and OKT4+ cells diminished the proliferative responses of AMLR cultures. Interaction of T cells with autologous monocytes resulted in generation of cells capable of suppressing both MLR and AMLR cultures. The suppressor activity of these cells was diminished by treatment with OKI , OKT4 or OKT8 monoclonal antibodies. No cytotoxic activity to autologous or allogeneic monocytes was observed. Additional studies showed an increased number of OKT9 + and OKI + as well as OKT8+ T cells in the AMLR responder cell population. This study indicates that cultures of T lymphocytes with autologous monocytes yield T cell subset(s) which suppress MLR and AMLR reactivity.