Modulation of the locomotory capacity of human large granular lymphocytes

The regulation of the migratory capacity of Percoll-purified large granular lymphocytes (LGL) into nitrocellulose filters was studied in a 2-hr assay with the use of modified Boyden chambers. Compounds that stimulate the natural killer cytotoxic function of LGL, such as interferons (natural beta, recombinant alpha A, recombinant hybrid alpha A/D, recombinant gamma), recombinant interleukin-2, and inactivated streptococci (OK 432), augmented the capacity of LGL to penetrate into filters spontaneously in the absence of chemoattractants in the lower compartment of the chamber. These compounds did not increase the LGL responsiveness to chemoattractants. Phorbol 12-myristate 13-acetate did not appreciably affect the locomotory capacity of LGL but augmented their cytotoxic activity. Thus the cytotoxic function and locomotion of LGL in response to biological response modifiers can be dissociated.     

Natural killer (NK) and lymphokine-activated killer (LAK) cell functions from healthy dogs and 29 dogs with a variety of spontaneous neoplasms

To investigate natural killer (NK) and lymphokine-activated killer (LAK) cell functions from 10 healthy dogs and 29 dogs with a variety of spontaneous neoplasms, large granular lymphocytes (LGLs) from blood samples were separated by a 58.5% Percoll density gradient. LGLs were stimulated with a low dose of recombinant human interleukin 2 (rhIL-2) for 7 days. Cytotoxicity of effector cells against the susceptible CTAC cell line was measured before and after stimulation. Compared with those before stimulation, the percentage of LGLs after stimulation with rhIL-2 was found to be significantly increased (P<0.01) in both dogs with tumors and controls. However, the increase was significantly higher in control animals, indicating a defect in proliferation ability of NK cells in canine tumor patients. After stimulation with rhIL-2, lymphokine-activated killer (LAK) cell activity in dogs with tumors was significantly lower (P<0.01) when compared with controls. Reduced cytotoxicity of rhIL-2–activated NK cells in dogs with tumors seems to be attributable to the presence of a diminished proliferative capacity of NK cells and a decreased ability of LAK cells to lyse target cells. Further knowledge of the precise function of IL-2–activated NK cells in dogs with tumors may help to optimize new and therapeutically beneficial treatment strategies in canine and human cancer patients. Our findings suggest that the dog could also serve as a relevant large animal model for cancer immunotherapy with IL-2.     

Bone marrow cell modulation and inhibition of myelopoiesis by large granular lymphocytes and natural killer cells

Non-adherent Percoll-separated large granular lymphocytes (LGLs) fractionated by fluorescence-activated cell sorter into CD16+ CD4- natural killer (NK) cells and CD16- CD4+ T cells, were co-cultured with bone marrow (BM) cells previously depleted of adherent T and/or NK cells by immunoadsorption (panning) and plated in a clonogenic assay to assess myeloid colony formation (CFU-gm growth). LGLs, NK cells and LGL T cells [low buoyant density (LBD) T cells] each significantly reduced colony-stimulating factor (CSF)-dependent CFU-gm growth to 70% of control values (p less than 0.05). Non-LGL T cells [high buoyant density (HBD) T cells] did not affect this growth. Incubation of the effector cells with human recombinant interleukin 2 prior to co-culturing did not alter these findings. The supernatants obtained from LGLs, NK cells and LBD T cells co-cultured with BM cells also inhibited CFU-gm growth to 70% of the control, whereas supernatants from effector cells which were not co-cultured with BM had no such effect. These supernatants from the LGL:BM co-cultured cells possessed NK cytotoxic factor (NKCF), but lacked alpha and gamma interferons, tissue necrosis factor-alpha, and prostaglandin E2. These results suggest that BM cells stimulate LGLs to produce NKCF, and that LGLs, CD16+ NK cells, and CD4+ CD16- LBD T cells activated by contact with BM cells inhibit CFU-gm growth.     

The effect of RU 41.740 (Biostim) on the production of interleukin-1 by monocytes and enriched large granular lymphocytes in normals and patients with hepatocellular carcinoma

Summary The effect of RU 41.740 on natural killer (NK) cell cytotoxicity from normals and patients with advanced hepatocellular carcinoma (HCC) was studied. RU 41.740-treated normal enriched large granular lymphocytes (LGLs) showed increased cytotoxic activity against ⁵¹Cr-labelled K562 cells. Although the drug increased the cytotoxic activity of LGLs from HCC patients, these results were not statistically significant. As LGLs have been shown to release interleukin-1 (IL-1) after suitable stimulation the effects of RU 41.740 on production of this cytokine from both monocytes and LGLs was studied. The drug stimulated IL-1 release from normal cells but monocyte and LGL IL-1 production from HCC patients was not influenced by RU 41.740 by RU 41.740. It is concluded, therefore, that although RU 41.740 can stimulate natural cytotoxicity and IL-1 production by normal LGLs, it is unable to correct the defect which exists in these functions in patients with large mass tumours.     

Defective interleukin-1 production by natural killer cells of patients with cancer

Summary Large granular lymphocytes (LGLs) from patients with malignant disease and from controls were activated by endotoxin or K562 cells, and the supernatants assayed for interleukin-1 (IL-1) activity. Normal LGLs produced significant amounts of IL-1, the activity of which could be neutralized by anti-human IL-1 antiserum. In patients with advanced cancer depressed IL-1 production was observed, which generally correlated with the degree of cytotoxicity produced by the LGLs. Prior treatment of the LGLs with interferon increased production of IL-1 by both control and patient cells. It is suggested that LGLs coming into contact with K562 cells produce IL-1, which is important in the effector-target cell interaction. The decreased cytotoxic activity of LGLs from cancer patients could be related to a defect in IL-1 production, an effect which can be partially corrected by in vitro interferon treatment.Abbreviations IL-1 Interleukin-1 - LGLs large granular lymphocytes - NK cells natural killer cells - IFN interferon - IL-2 interleukin-2 - HCC hepatocellular carcinoma - MN mononuclear cells - LPS lipopolysaccharide Supported in part by grants from the South African Medical Research Council, the National Cancer Association of South Africa, and the South African Chamber of Mines     

Functional properties of T cells in patients with chronic T gamma lymphocytosis and chronic T cell neoplasia

The expanded T cell populations of 10 patients with either T gamma lymphocytosis (five patients) or proven chronic T cell malignancy (five patients) were analyzed with respect to functional activity in vitro, including proliferative responses to mitogens, cytotoxic activity (killer [K] and natural killer [NK] cell activity), and regulatory activity on pokeweed mitogen- (PWM) induced immunoglobulin (Ig) synthesis (help and suppression) in comparison with marker phenotypes. In each of the five patients with T gamma lymphocytosis, only one out of three functionally distinct cell types was found: T gamma-K cells, T gamma-S cells, or T gamma-NK/K cells, which mediated K-cell activity, suppressive activity, and both NK and K cell activity, respectively. An expanded T gamma-K cell population was demonstrated in three patients with neutropenia with or without recurrent infections. T gamma-S cells were found in a patient with severe hypogammaglobulinemia, and T gamma-NK/K cells in one patient with asymptomatic lymphocytosis. T gamma-K and T gamma-S cells had a similar surface-marker profile (E+ or E-, Fc gamma+, OKT1-3+4-8+I1-M1-), whereas that of T gamma-NK/K cells was different (E+, Fc gamma+, OKT1-3-4-8-I1+M1+). Longitudinal studies of three untreated patients with T gamma-K lymphocytosis showed that the abnormalities were persistent but not progressive. In contrast, five patients with chronic T cell malignancy (two with T-CLL, two with cutaneous T cell lymphoma [CTCL], and one with T-PLL) all had progressive disease. The neoplastic cells in these cases were E+, Fc gamma-OKT1+4+6- with variable expression of the OKT3 and OKT8 markers. The only functional activity observed in these cells was suppressive activity by OKT3-4+8- cells from a patient with CTCL.     

In vitro migration of rat large granular lymphocytes

Rat peripheral blood large granular lymphocytes (LGL) were isolated by fractionation on discontinuous Percoll gradients. LGL migration was studied using nitrocellulose filters. Rat LGLs migrated into nitrocellulose filters in response to N-formyl-methionyl-leucyl-phenylalanine (f-MLP), casein, and serum components. Percoll-enriched high-density lymphocytes had small, but significant, migratory capacity in response to stimuli under these conditions. Removal of OX-19+ contaminating cells by panning confirmed the migratory capability of rat LGL/NK cells under these conditions. Checkerboard analysis of the LGL response to chemoattractants revealed that induction of migration involved chemokinesis although a chemotactic component was also discernible. The prompt migration of rat LGL in response to different stimuli is consistent with the hypothesis that these cells may represent one of the first easily mobilizable lines of resistance against noxious agents. In the rat combined in vitro/in vivo studies may provide a better understanding of the regulation of LGL recruitment and extravasation.     

Production of hemopoietic growth factors and gamma-interferon by large granular lymphocytes from patients with T gamma lymphocytosis

Two patients with T gamma lymphocytosis in whom expanded large granular lymphocyte (LGL) populations were detected in peripheral blood and bone marrow are described. The surface antigen phenotypes of the LGL from these patients were similar with a major portion of cells carrying T3, T8, T11 and Leu7 markers. However, whereas fresh LGL from both patients demonstrated antibody-dependent cell cytotoxicity (ADCC), natural killer (NK) cell function was present in one case but absent in the other. Supernatants from enriched suspensions of the LGL unstimulated by exogenous antigen or mitogens were shown to contain significant amounts of hemopoietic growth factors colony-stimulating activity (CSA) and burst-promoting activity (BPA). In one case gamma-interferon was also detected. This study contributes to the accumulating evidence that LGL are able to generate factors which have the capacity to influence the proliferation of hemopoietic progenitor cells in vitro.     

Selective inhibition of natural killer activity by the monoclonal antibodies OKT10 and VEP10 at the single cell level

The monoclonal antibodies, VEP10 and OKT10, which have been shown to recognize determinants on human natural killer (NK) cells, inhibit large granular lymphocyte (LGL) NK activity against K562, MOLT4, and CEM tumor target cells in the single cell conjugate agarose assay. Inhibition of NK activity by monoclonal antibodies was expressed independently of effector-target cell binding, as inhibitory activity could be demonstrated when the monoclonal antibodies VEP10 and OKT10 were added to preformed conjugates or to the LGLs and targets prior to the binding event. In addition, this inhibition was exerted on the effector cell and not the target cell since VEP10 and OKT10 did not react with determinants on K562 target cells. Furthermore, the 4F2 monoclonal antibody, which reacted with determinants on the LGL and all of the targets used, effected no inhibition of NK activity. Inhibition of killing by OKT10 and VEP10 was specific to endogenous NK activity since the same antibodies did not inhibit antibody-dependent cellular cytotoxicity (ADCC), mixed lymphocyte-generated NK, or cytotoxic T lymphocyte (CTL) activities.     

Alterations in cell-surface carbohydrates of rat large granular lymphocytes associated with interleukin-2 activation

The activation of large granular lymphocytes (LGLs)/natural killer (NK) cells with interleukin-2 (IL-2) has been shown to increase the ability of these cells to lyse NK-resistant tumor target cells. Activated LGLs, termed LAK (lymphokine-activated killer) cells, have been demonstrated to be of therapeutic value in vivo against metastatic tumors. The mechanism by which IL-2 induces broadened cytolytic capability, as well as the molecular basis of target recognition and killing by the activated cells has not yet been elucidated. Since carbohydrate moieties have been demonstrated to be of possible significance in the cytolytic cascade of a variety of effector cells, the current study was undertaken to determine if the activation of LGLs with IL-2 is accompanied by an alteration of cell-surface carbohydrates. Two-color flow cytometry was performed to identify LGL/NK cells in populations of nylon wool-nonadherent splenic mononuclear cells and to assess the binding of various lectins to activated as well as nonactivated LGLs. Increases were observed in the binding of four lectins to LGLs after IL-2 activation; Triticum vulgaris (wheat germ agglutinin), Phytolacca americana (pokeweed mitogen), Lycopersicon esculentum (tomato lectin), and Griffonia simplicifolia I-B4 (GSI-B4). The wheat germ, pokeweed, and tomato lectins recognize complex carbohydrates structure consisting of GlcNAc(Bl,4GlcNAc)n while GSI-B4 recognizes alpha-D-galactose terminal end groups. Lectin binding to the activated LGLs was homogenous (i.e., flow cytometry revealed only a single population of fluorescent cells). Lectin binding to LGLs prior to activation was more heterogeneous, however, the tomato lectin uniquely revealed a bimodal distribution of receptors. These data indicate that LGL/NK cells from the rat are heterogeneous in their ability to bind specific lectins, and that IL-2 activation of these cells results in altered expression of specific cell-surface carbohydrates.     

Inert particles inhibit natural killer cell function in vitro

Aqueous suspensions of inert particles were found to inhibit the baseline and interferon-enhanced natural killer (NK) cell activity of peripheral blood mononuclear cells (PBMC) and large granular lymphocytes (LGLs). This inhibition was induced with latex, silica, and Sephadex particles. The suppression of NK activity was not related to effector cell death as determined by trypan blue exclusion. The inhibition of NK cell function was more pronounced with prolonged incubation and could be partially reversed with monocyte depletion or the addition of indomethacin, a prostaglandin synthesis inhibitor, but not with the addition of the lipoxygenase inhibitors nordihydroguaiaretic acid and BW755C. Similarly, particle exposure inhibited the NK cell function of monocyte-depleted large granular lymphocytes with and without the add-back of glass adherent cells, implying that monocyte-independent NK suppressive mechanisms were also present. These data demonstrate that inert particles are immunosuppressive in vitro and can inhibit baseline and interferon-stimulated NK cell function of LGLs and PBMC through monocyte-dependent and independent pathways.     

Natural killer cell activity in mice infected with Acanthamoeba culbertsoni]

The natural killer cell activity of splenocytes and TBC, active NK cells, recycling capacity of natural killer cells were observed by means of both the 51Cr-release cytotoxicity assay and single cell cytotoxicity assay against YAC-1. C3H/HeJ mice were infected intranasally with 1 x 10(4) or 1 x 10(5) trophozoites of pathogenic Acanthamoeba culbertsoni. The infected mice showed mortality rate of 34% in 1 x 10(4) group and 65% in 1 x 10(5) group, and mean survival time was 16.40 +/- 3.50 and 13.20 +/- 4.09 days respectively. The cytotoxic activity of natural killer cells of the 2 groups was significantly higher than that of non-infected mice from the 12th hour to the 2nd day after infection, showing the highest on the first day. On the 10th day after infection, the cytotoxic activity of natural killer cells was significantly suppressed as compared with that of the control. There was no significant difference in NK cell cytotoxicity between two infected groups. The target-binding capacity and active NK cells of natural killer cells in 1 x 10(5) trophozoite infected mice was significantly increased on the 12th hour and the first day after infection as compared with the control group. Maximal recycling capacity (MRC) was not changed during the observation period. The present results indicated that the elevation of natural killer cell activity in the mice infected with A. culbertsoni was due to elevation of target-binding capacity and increased active NK cells of natural killer cells, and not due to the maximal recycling capacity of the individual NK cell, and there was no difference between two experimental dose groups.     

T-cell receptor gene rearrangements and expression in normal human large granular lymphocytes (LGL) and their pathological expansions

The lineage to which normal large granular lymphocytes/natural killer (LGL/NK) cells belong is controversial; in fact they share some surface markers and functional activities with monocytes, but also with T lymphocytes. The relationship of LGL to the T cell lineage by analysis with the T cell receptor (T-rec) gene has been investigated. Pure preparations of human LGL and their CD11⁺ CD8^- and CD11^- CD8⁺ subsets had the T gene in its unrearranged germline configuration. Expression of T and T genes was not detectable. The organization of T gene, which is of particular importance because it occurs early in T cell ontogeny, was also found in its germline configuration.A rare type of lymphoproliferative disorder, termed T-LPD, is characterized by expansion of cells very similar to LGL for morphology, phenotype, and functional activity. Of 17 patients with T-LPD studied for T-rec rearrangement, 15 displayed rearrangement of T and T loci and were CD3+ (14/15 had monoclonal rearrangement), while 2 cases were in germline configuration and were CD3–. Similarly to very small subsets of CD3+ LGL recently described, most T-LPD cases are CD3+ and have T-rec genes rearranged. These data suggest that either a subset of LGL or a particular step of differentiation may be related to the T cell lineage; they also demonstrate that, in contrast to previous views, most TLPD are monoclonal, presumably neoplastic, lymphoproliferative disorders.Abbreviations LGL large granular lymphocytes - NK natural killer - T-rec T-cell receptor - TLPD T lymphoproliferative disease     

CD16 on human gamma delta T lymphocytes: expression, function, and specificity for mouse IgG isotypes.

We examined the expression, the signal transduction capacity and mouse IgG-isotype specificity of CD16 on human gamma delta T cells. CD16 is expressed by the majority of gamma delta T cells in peripheral blood and by part of the gamma delta T cell clones. The amount of CD16 expressed on gamma delta T cell clones varied considerably with passaging of the cells, but was always significantly less than on freshly isolated gamma delta T cells. Like CD16 on CD3- CD16+ natural killer (NK) cells, CD16 on gamma delta T cells can act as an activation site triggering cytotoxic activity. CD16+ gamma delta T cell clones exerted antibody-dependent cellular cytotoxicity (ADCC) which could be blocked by anti-CD16 mAb. ADCC activity of gamma delta T cell clones was also inhibited by anti-CD3 mAb, suggesting a functional linkage between the CD16 and CD3 activation pathways. MAb directed against CD16 induced lysis of Fc gamma R+ target cells by CD16+ gamma delta T cell clones. The mouse IgG-isotype specificity of CD16 on gamma delta T cells was analyzed using isotype switch variants of a murine anti-glycophorin A mAb in EA rosette assays, and was found to be identical to that of CD16 on CD3- CD16+ NK cells, i.e., highest affinity for mIgG2a, intermediate affinity for mIgG2b, and undetectable binding of mIgG1-sensitized erythrocytes. CD16 was partly modulated from the cell surface of both gamma delta T cells and NK cells after rosette formation with mIgG2a-sensitized erythrocytes, indicating that the rosette formation was indeed mediated via the CD16 molecule.     

Ultrastructural analysis of HNK-1+ cells in human peripheral blood and lymph nodes

HNK-1 positive (HNK-1+) cells in human peripheral blood and lymph nodes were comparatively analysed by means of immunohistochemistry and immunoelectron microscopy. In peripheral blood, the HNK-1+ cells were grouped into large granular lymphocytes (LGLs), small lymphocytes and intermediate forms, all of which had many fine cytoplasmic processes. Except for smooth-surfaced lymphocytes, they could not be distinguished from helper/inducer T (OKT4/Leu3a) cells and suppressor/cytotoxic T (OKT8/Leu2a) cells. In double staining, HNK-1+T3- cells and HNK-1+T3+ cells could not be clearly distinguished in terms of morphology, although the former contained many LGLs. The HNK-1+ cells in the lymph nodes accumulated in the light zones of the germinal centers (GCs). These cells were small to medium-sized lymphocytes with few electron-dense granules and exclusively co-expressed helper/inducer T cell antigens (HNK-1+T4+). Their cytoplasmic projections were interwoven with those of the follicular dendritic cells which trap immune complexes for a long duration. These configurations suggest that HNK-1+T4+ cells in GCs are engaged in an immunological regulation of germinal center cells. On the other hand, large blastic HNK-1+ cells were scattered outside the GCs and some of them were in the process of mitosis. Furthermore, HNK-1+LGL-like cells with a few large electron-dense granules were rarely seen. These observations indicate that the HNK-1+ cells in the lymph nodes may proliferate outside GCs and differentiate into LGLs with a strong natural killer function.     

Development of hyporesponsiveness to augmentation of natural killer cell activity after multiple doses of maleic anhydride divinyl ether: association with decreased numbers of large granular lymphocytes

A single injection of mice with maleic anhydride divinyl ether (MVE-2) resulted in significantly augmented natural killer (NK) activity. However, multiple injections with MVE-2 led to a hyporesponsive to boosting of NK activity. Stimulation of prostaglandin E secretion of induction of suppressor macrophages (M phi) or lymphocytes were shown not to be responsible for the depressed NK cell responses. Rather the hyporesponsiveness to NK boosting was associated with a decreased number of large granular lymphocytes (LGLs). Percoll discontinuous-density-gradient studies showed that the augmented NK activity of spleen cells after a single injection with MVE-2 was associated with an increase in the percentage of LGLs in the lower-density fractions (Fraction 1 and 2). In contrast, the NK activity and percentage of LGLs in the lower-density fractions were markedly decreased after multiple injections with MVE-2. Polyinosinic: polycytidylic acid stabilized with poly(L-lysine) in carboxymethylcellulose, another BRM capable of augmenting NK activity, was able to substantially augment NK activity in mice hyporesponsive to MVE-2 and this was accompanied by an increase in the percentage of LGLs in the lower-density Percoll fractions.     

Increased number of functionally defective large granular lymphocytes in lymphoma patients

50 untreated patients with either Hodgkin's disease or non-Hodgkin lymphoma were studied for natural killer (NK) activity on the single cell level. The non-Hodgkin lymphoma patients had a significantly higher proportion of large granular lymphocytes-cells mediating the natural cell mediated cytotoxicity in humans-among peripheral blood lymphocytes. Yet, the single cell assay in agarose and the standard 51Cr assay revealed a significantly decreased capacity to bind and lyse the K562 target cells. The recycling capacity was also found to be lower in the lymphoma patients' NK cells compared to the healthy controls.     

Relationship between immune system and gram-negative bacteria. II. Natural killer cytotoxicity of Salmonella minnesota Rb 345-unbound human peripheral blood lymphocytes

Spontaneous binding of human peripheral blood lymphocytes (PBL) to bacteria represents a promising approach for the characterization of lymphocyte subsets mediating different functions. In the light of previous findings on the high degree of spontaneous adherence of S. minnesota Rb cells to PBL, we have evaluated the natural killer (NK) cytotoxicity of PBL subpopulations that fail to bind to Rb bacteria. The S. minnesota Rb-unbound cell fraction exhibits higher levels of cytotoxic capacity, which is related to a more elevated frequency of active NK cells, as determined in an agarose-single cell cytotoxic assay. Moreover, the cytotoxic activity of the unbound fraction is additionally boosted by interferon-alpha pretreatment. The effector cells bear Fc gamma receptors that are involved in NK cell lysis, because a decrease of NK activity is observed after immune complex modulation of the receptors. Finally, these cells, which display a high percentage (approximately 70%) of typical large granular lymphocyte morphology, express HNK-1, T10, T8, and M1 antigens, and to a lesser extent T3 and T4 antigens. These data indicate a selective enrichment of NK cells in the S. minnesota Rb-unbound fraction.     

Prognostic role of natural killer cells in pediatric mixed cellularity and nodular sclerosing Hodgkin's disease

OBJECTIVE: To study natural killer cells' spontaneous cytotoxic capacity against tumor cells and their prognostic significance in classical Hodgkin's disease. STUDY DESIGN: Thirty-eight pediatric mixed cellularity and nodular sclerosing Hodgkin's disease patients were included in the study. Immunohistochemical staining was performed for natural killer cells in the background using the monoclonal antibody CD57 in serial sections of B5-formalin-fixed, paraffin-embedded tissue blocks. CD57-positive cells were counted with an immersion objective among 5,000 cells on representative areas of the tumors. The degree of natural killer cells was classified as low (<150 cells) or high (> or = 150 cells). Multivariate regression analysis was performed to determine the differences between patients with and without relapse. RESULT: The mean of CD57-positive cell numberfor all the cases was 173.42 +/- 117.34 (range, 20-500). CD57-positive cells were high in 21 cases and low in 17. The mean of CD57-positive cell numbers was 191.85 +/- 115.33 in the disease-free group and 84.44 +/- 57.90 in the relapsing group. Log rank analysis showed statistical significance between event-free survival and number of CD57-positive cells (P = .0207). CONCLUSION: In multivariate analysis, CD57 expression proved to be a prognostic factor independent from otherfactors. As a result, CD57 expression by background natural killer cells may be used as a prognostic parameter in mixed cellularity and nodular sclerosing Hodgkin's disease.     

Recombinant interleukin 2 rapidly augments human natural killer cell activity

Recombinant human interleukin 2 (r-IL-2) rapidly stimulated human natural killer cell activity in vitro. Augmentation of NK activity occurred within 1 hr of preincubation with r-IL-2. Responsive killer cells were typical NK cells as shown by cell fractionation procedures. These included Percoll density gradient separation and depletion of OKT3+ T cells by an indirect rosetting method. Analysis with a panel of polyclonal and monoclonal antibodies against alpha and gamma interferon revealed that this early enhancement of NK activity by r-IL-2 was independent of the production of both types of interferon.