Regulation of natural killer cell activity by anti-I-region monoclonal antibodies*1 (original) (raw)
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Regulation of natural killer cell activity by anti-I-region monoclonal antibodies
Cellular Immunology, 1984
The effects of a monoclonal antibody directed against immune response gene products on mouse NK activity were examined. In vivo administration of an anti-I-Ak antibody to C3H/He (H-2') mice modulated their peritoneal cell (PC) and spleen cell (SC) natural killer (NK) activity against YAC-1 lymphoma target cells in vitro. No such effect was observed when BALB/c (H-2d) mice were treated with this antibody. Administration of anti-I-A' antibody to mice before and after infection with Toxoplasma or treatment with poly(I:C) leads to suppression of NK activity in comparison to NK activity of mice infected with Toxoplasma or injected with poly(I:C) alone. A similar treatment regimen with M5/114 antibody which reacts with I-Ab, I-Ad, I-Ed, and I-Ek molecules resulted in decreased NK activity in BlO.D2 (H-2d) but not in BlO.BR (H-2') mice. Serum and cell culture supematant interferon (IFN) concentrations were not altered as a result of anti-I-A' treatment. Removal of adherent cells did not restore NK activity of anti-I-Ak-treated Toxoplasma-infected mice to levels obtained with mice infected with Toxoplasma. In contrast, depletion of Ly 2.1+ cells from nylon-wool nonadherent SC of mice treated with anti-I-Ak antibody, before and alter infection with Toxoplasma, resulted in restoration of NK activity to the same level as that observed in Toxoplasma-infected mice.
Comparison of NK Activity in Mouse Spleen and Peripheral Blood Lymphocytes
Immunobiology, 1988
Natural killer (NK) cells originating in mouse peripheral blood were studied with regard to their lytic activity against YAC-1 target cells and to their expression of asialo-GM1 marker on their surface. In Balb/c, CBA/LAK and A/J mice, PBL were found to be approximately twice as effective as splenocytes. Splenic and peripheral NK cells were shown by flow cytometry to have similar lytic potential per cell; the difference in NK activity found in the spleen and in PBL was solely due to the differences in the size of the NK cell population found in the two sites. Strain distribution of NK activity in PBL followed the same pattern observed in splenocytes. The difference in NK activity between CBA and Balb/c mice was shown to be due to the fact that the lytic potential per NK cell was approximately twice as high in the former.
Enhancement of human natural killer cell activity by subcellular components of Toxoplasma gondii
Cellular Immunology, 1984
The ability of sonicates and subcellular fractions of the intracellular parasite Toxoplasma gondii to enhance in vitro human natural killer (NK) cell activity was examined. Incubation of nylon-wool-non-adherent human peripheral blood lymphocytes (PBL) with sonicatks of T. gondii for 18-72 hr resulted in increased NK activity against an NK-sensitive, as well as an insensitive, target cell. Single-cell assays revealed that augmentation of NK activity was not due to an increased binding of K562 target cells to effector cells. Differential centrifugation studies indicated that NK-augmenting activity was distributed in membrane-enriched and cytoplasmic fractions. This activity was found to be resistant to treatment with ribonuclease (RNase) and deoxyribonuclease (DNase), but susceptible to proteolysis. Antibodies present in the serum of humans infected with Toxoplasma blocked the NK cell-augmenting effect of the membrane-enriched fractions. Enhancement of NK activity by PBL incubated with Toxoplasma sonicate was accompanied by a concomitant increase in interferon (IFN), but not of interleukin 2 (IL2), levels in supematants of the cell cultures.
In Vivo Generation of Mouse Natural Killer Cells: Role of the Spleen and Thymus
Scandinavian Journal of Immunology, 1978
The role of the spleen and thymus was investigated in the natural killer {NK) cell system. These NK cells have the ability to kill a variety of tumour cells as demonstraled in vitro in short-term '*Cr release assays. The work presented deals with three observations: (1) the effect of splenectomy on the levels of NK aclivily in the blood and lymph nodes. (2) ihe elTeci of splenectomy on the reconstitution of irradiated animals with hone marrow cells, and (.1) the kvel of NK aetivity in adult ihymectomized. irradiated animals which were reconsiituted with bone marrow or thymus cells from either high or low NK activity animals. Thus, for the third point, chimaeras were established between histocompaiible strains of miee A.BY (a low NK strain), and C57BI/6 (a high NK strain). The ability of T cells from one strain could then be observed lo eilher help or suppress the NK activity of the bone-marrow-derived cells. The daia presented show that the absence of a spleen does not affect NK activity or reconstitution of N K cells in irradiated animals. Further, T eells from one strain do not affect NK activity of animals rcconstiluled with bone marrow eells from a histoconipatible strain. Thus T cells from a low NK. stain (A.BY) did not suppress the high activity of C57B1/6 cells, and. conversely, the C57BI/6 T cells did not competisate for the low NK activity of A.BY cells.
Scandinavian Journal of Immunology, 1978
Mouse normal lymphoid cells were analysed as to their ability to perform in three cytolytic systems: Ability to act as 'natural killer', NK, cells against a NK sensitive tumour target, YAC; as effector cells against IgG-coated P815 cells, or to function as effector cells against IgG-coated CRBC. NK activity and ADCC against the IgG-coated P815 cells were found to vary in parallel as affected by age, organ distribution and genotype of the effector cells. On the other hand, ADCC against CRBC was largely carried out by effector cells distinct from those functioning as NK cells or in ADCC against P815. Temperature pretreatment schedules at 37°C showed both NK cells and ADCC ability against P815 to be highly sensitive in contrast to ADCC against CRBC. Likewise, inoculation of Corynebacterium parvum intraperitoneally will lead to reduction in ADCC ability against CRBC but increase in ADCC against P815 and NK activity. Blocking experiments using 'cold' inhibitor cells in the cytolytic assays indicated that NK cells and effector cells against IgGcoated P815 cells are the very same cells. We thus conclude that NK cells in the mouse also have the ability to express K cell activity against IgG-coated tumour target cells. In fact, our data suggest that the NK cells may be the only cell type in the mouse equipped with cytolytic potential for antibody-coated murine nucleated cells.
Kinetics and Regulation of NK Activity by Interleukin-2 and Interferon in Acute Toxoplasmosis
Scandinavian Journal of Immunology, 1991
Diez B, Nicolas R, Galdeano A, Cisterna R, Canavate ML. Kinetics and Regulation of NK Activity by Interleukin-2 and Interferon in Acute Toxoplasmosis. Scand J Immunol 1991;34:683-7 Natural killer (NK) activity against Toxoplasma gondii tachyzoites and tumour cells during acute toxoplasmosis was investigated using a single-cell NK assay. During the course of infection the percentage of lymphocytes binding tachyzoites and tumour cells did not vary significantly and NK activity was enhanced due to an increase in the specific cytolytic capacity per cell. To determine whether regulatory mechanisms mediated by cytokines might explain the increased NK activity, the kinetics of interleukin-2 (IL-2) and interferon (IFN) production and the correlation between their concentrations and the level of NK activity were analysed at the same time. As the infection progressed NK activity increased in spite ofthe fact that IL-2 production decreased (except for a small increase during the first day of infection). However, IFN production increased gradually in close temporal and quantitative association with the overall increase in NK activity. These results suggest that T. gondii, via its ability to produce interferon, enhances NK activity against itself and other cells.