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Serum levels of IL-12 and the production of IFN-gamma, IL-2 and IL-4 by peripheral blood mononuclear cells (PBMC) in cancer patients treated with Viscum album extract.

A dysregulation between cellular immunity (Th1 cells) and humoral immunity (Th2 cells) is a characteristic of cancerous diseases. Viscum album (VA) extract has an immunomodulatory effect and can be used in the treatment of cancer patients, either following or in combination with chemo- /radiotherapy. In this pilot study, we investigated the effect of VA extract on the serum levels and production of cytokines in a group of cancer patients undergoing treatment (N = 16) in comparison with healthy untreated controls (N = 11). The serum levels of interleukin-12 (IL-12) (p40 and p70), and the production of gamma interferon (IFN-gamma), interleukin 2 (IL-2), and interleukin-4 (IL-4) in peripheral blood mononuclear cells (PBMC) were measured in patients before treatment and on days 3, 5, 8, 15, and 21-29 during therapy, and in the control group at the same time intervals over a two-week period. Cytokine levels were determined by ELISA. In cancer patients, the serum levels of IL-12 (p40 and p70) before therapy were about 3-fold higher than in controls. They increased during therapy, with a borderline significance (Wilcoxon paired signed-rank test, P = 0.06). In PBMC the production of IFN-gamma and IL-2 (before therapy respectively 3-fold and 9-fold lower than in controls) increased significantly (Wilcoxon paired signed-rank test and Mann-Whitney U-test, P < 0.05) during treatment. In PBMC, IL-4 production was in the same range as in controls, and remained unaltered during therapy. In conclusion, the results of this study show that treatment with VA extract leads an increase in Th1 cytokine levels (IFN-gamma and IL-2), which suggests that cell-mediated immunity could be positively affected.

Cells, Cultured↗

[Palliative immunotherapy of cancer].

In addition to surgery, chemotherapy and radiation, immunotherapy of cancer resembles a potential treatment strategy for patients with cancer. To strengthen the immune system might help to control or even to eradicate malignant tumors. Immunoaugmentative strategies include biological response modifiers as interferons and interleukins. Recently, monoclonal antibodies directed against tumor associated antigens and coupled with radioisotopes or cytotoxic agents have become available. Adoptive immunotherapy uses immune effector cells, i.e. T-cells or natural-killer cells that are activated in-vitro by appropriate cytokines. Dendritic cells, either unstimulated or pulsed with tumor derived molecules have shown promising anticancer activity in selected tumors. Immunonutrition, that is the manipulation of immune phenomenons through edibles is a new and interesting topic. Immunologic strategies for the treatment of malignant diseases are currently under intensive preclinical and clinical investigation. Further insights into the mechanisms of host-defense against cancer cells and the modification of immune-effector cells might pave the way to efficient treatment strategies, even in the palliative setting.

Antibodies, Monoclonal↗

Accidental cell death and generation of reactive oxygen intermediates in human lymphocytes induced by thionins from Viscum album L.

The cytotoxic mechanisms of thionins from Viscum album L., the viscotoxins, were investigated in human granulocytes and lymphocytes. The time course of viscotoxin effects indicate accidental cell death, i.e. membrane permeabilization, degradation of cytoplasm and chromatin, swelling of mitochondria with loss of their cristae, and generation of reactive oxygen intermediates within 1-2 h, followed by secondary apoptosis-associated events. The viscotoxin homologue purothionin from whole-wheat flour and viscotoxin B, however, did not induce cell death in cultured lymphocytes. Cytotoxicity of cationic and amphipathic viscotoxin was prevented only by cleavage of its disulphide bridges.

Apoptosis↗

Selective modulation of phosphatidylserine exposure on subpopulations of human peripheral blood lymphocytes by a plant lectin, Viscum album agglutinin (VAA)-I and its recombinant form (rVAA) in vitro.

Growing evidence suggests that lectin-carbohydrate interactions are involved in the regulation of the balance between cell growth and programmed cell death. Viscum album agglutinin (VAA)-I is a galactoside-specific, type II ribosome-inactivating plant lectin. At concentrations less than 10 ng/ml, VAA-I has been shown to induce gene expression and secretion of proinflammatory cytokines as well as apoptosis in cultures of human peripheral blood mononuclear cells (PBMC). This study analyzes the effects of VAA-I and its recombinant nonglycosylated form (rVAA) on alterations of cell membrane permeability of cultured human peripheral lymphocytes (PBL) and on membrane exposure of phosphatidylserine characteristic of apoptosis. Analyses were performed by flow cytometry after staining with propidium iodide (PI) and/or with FITC-Annexin V/PI. After 24 h incubation of PBMC with 100 ng/ml VAA-I and rVAA, staining with supravital concentration of PI (20 microg/ml) for 1 h revealed no differences in percentages of PI-positive cells induced by the two forms of lectin (32.3% and 29.4%), but the exposure to 5 microg/ml PI for 15 min resulted in a significant difference: 35.1% and 8.0% after VAA-I and rVAA treatment, respectively. Kinetic analysis of membrane alterations showed mainly Annexin V positivity after 24 h, whereas after 48 h and 72 h incubation with 100 ng/ml VAA-I or rVAA loss of membrane integrity occurred, as demonstrated by PI staining. Similar to VAA-I, rVAA showed a higher binding affinity for monocytes and granulocytes than for lymphocytes. In cultures of PBL, the binding rank order of both lectins to lymphocyte subsets was NK, CD19+ > CD8+ > CD4+. The amount of Annexin/PI staining of PBL subsets corresponds to the degree of their binding capacity. In conclusion, present results demonstrate that VAA-I and its nonglycosylated recombinant form rVAA exhibit comparable effects on cell membrane alterations in the subsets of human PBLs.

Annexins↗

Influence of the galactoside-specific lectin from Viscum album and its subunits on cell aggregation and selected intracellular parameters of rat thymocytes.

Galactose-specific lectin from Viscum album (VAA) was shown to induce the aggregation of rat thymocytes, to increase the intracellular Ca(2+)-availability, and to enhance the menadione-dependent release of H2O2 from cells in a carbohydrate- and dose-dependent manner. This activity was mediated by the carbohydrate-binding B-subunit, whereas the toxic A-subunit failed to display aggregating activity or to affect the intracellular Ca2+. However, incubation of cells in its presence decreased the release of H2O2. These data extend the knowledge of the immunomodulatory potency of VAA, especially its carbohydrate-binding B chain.

Animals↗

Complete remission of a diffuse pontine glioma.

A patient is described in whom a large diffuse glioma of the pons extending into the midbrain was diagnosed at the age of 2 years. Biopsy showed a fibrillary astrocytoma. After shunting of a hydrocephalus, the clinical symptoms abated without conventional therapy. Repeated MRI studies showed a continuous decrease of the tumour which was no longer visible when the patient was 6.6 years old. In reviews on spontaneous remissions of oncologic disorders we were unable to find a case of a biologically benign brain stem tumour. There is one isolated report on a similar case, though without histologic documentation.

Antineoplastic Agents, Phytogenic↗

The influence of isorel on the advanced colorectal cancer.

There is still no therapy method in the colorectal cancers that is good enough for such a complex disease. Combined surgery, chemotherapy, and radiotherapy improved survival, but the side effects and the poor performance status of the patients seriously affect the use of these methods. We used a therapeutical approach of surgery and chemotherapy combined with biotherapy by Viscum album extract Isorel, aiming to improve the patients' resistance to the disease and to render the treatment's side effects more tolerable. Isorel is aqueous extract well known for its anticancer effects obtained by various in vitro and in vivo experimental models and which was validated by an in vitro bioassay on murine melanoma B16F10 and human cervical carcinoma HeLa cells. Isorel strongly reduced human colon cancer HT 29 cell line growth in vitro in the MTT bioassay. Hence, it was further used in a prospective, randomized, and controlled study which compared the postoperative results for patients with colorectal cancer stages Dukes C (40 patients) and D (24 patients) who, beside surgery, received either only chemotherapy (5-FU), 6 cycles (either the Mayo or the De Gramont protocol) or chemotherapy combined with Isorel biotherapy. These 64 patients were randomly allocated into three groups "only chemotherapy" for 21 cases, chemo + biotherapy for 29 cases and 14 patients underwent only surgery as the control group. We noted no toxic deaths due to either chemo or biotherapy. The patients operated on and treated with chemo and biotherapy had median survival significantly better and a cumulative proportion survival (Kaplan-Maier) superior to those of the patients receiving only postoperative chemotherapy. Thus, colorectal cancer patients seem to benefit in terms of survival from combined postoperative chemotherapy and Isorel biotherapy, either adjuvant or palliative.

Adult↗

Enhancement of human NK and LAK cytotoxicity against HCMV-infected cells by rhamnogalacturonan: specificity of reaction.

Human peripheral blood mononuclear cells (PBMC) and their subpopulations obtained from healthy donors were used to study improvement of MHC-unrestricted cytotoxic reactions against cells infected with human cytomegalovirus (HCMV) at different multiplicities of infection. Natural killer (NK) and lymphokine-activated killer (LAK) cytotoxicity against HCMV-infected cells was greatly enhanced in the presence of rhamnogalacturonan (500 ng/ml). The increase of the multiplicity of infection from MOI 0.1 to 1.0 had only a slight effect on cytotoxicity enhancement by rhamnogalacturonan. The chemical specificity of interaction of rhamnogalacturonan with effector cells and virus-infected cells was found to be analogous to the interaction with tumor cells, i.e., both types of target cells must express a receptor for rhamnogalacturonan since rhamnogalacturonan-mediated enhancement of NK and LAK cytotoxicity against HCMV-infected cells was similarly inhibited by preincubation of CD56+ effector cells with 60% deacetylated D-mannose pentaacetate.

Cells, Cultured↗

Immunomodulatory effects of Viscum album agglutinin-I on natural immunity.

In 24 h cultured human peripheral blood mononuclear cells, treated with various (1 microgram/ml to 1 ng/ml) concentrations of Viscum album agglutinin-I, quantitative assessment of DNA breaks labelled with terminal deoxynucleotidyl transferase revealed a dose-dependent Viscum album agglutinin-I-induced apoptosis above a lectin concentration of 10 ng/ml. After 24 h incubation of peripheral blood mononuclear cells with non-cytotoxic concentrations of Viscum album agglutinin-I (10 and 1 ng/ml), messenger (m)RNA expression and secretion of a panel of cytokines were evaluated by reverse polymerase chain reaction and by enzyme-linked immunosorbent assay (ELISA), respectively. The lectin induced expression of interleukin-1 alpha, interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha, interferon-gamma, granulocyte-monocyte colony stimulating factor and interleukin-10 genes, but no expression of interleukin-2 or interferon-gamma production could be detected. In addition, cellular components of the natural immune system (such as monocytes and granulocytes) bound Viscum album agglutinin-I molecules to a higher degree than lymphocytes. To establish the modulatory potency of Viscum album agglutinin-I on the natural immunity of human subjects, four randomized, double-blind crossover trials were performed on healthy volunteers. In contrast to the significant lectin-induced increases in number and activity of natural killer cells observed in animal models, in the first and second trial human healthy individuals showed no significant differences between their natural killer responses following an injection of lectin-enriched preparation or saline. Due to considerable intrinsic fluctuation of these parameters, a third and fourth double-blind trial with freshly isolated Viscum album agglutinin-I was performed using a more rapidly detectable parameter, the priming of granulocytes. Here, significant lectin-induced increases were found.

Agglutinins↗

Immunomodulatory and clinical effects of Viscum album (Iscador M and Iscador P) in children with recurrent respiratory infections as a result of the Chernobyl nuclear accident.

Ninety-two children 5 to 14 years of age living in areas exposed to the radioactive fallout from Chernobyl with recurrent respiratory infections (RRIs) were treated after randomization with either Viscum album praeparatum mali or pini (Iscador M or P). The dosage was two subcutaneous injections a week for 5 weeks with individual doses of 0.001 mg to 1.0 mg. Both Viscum album preparations were effective in significantly reducing clinical symptoms. One year after a single treatment course, the frequency of RRI relapses decreased by 78% and 73%, respectively. Immunomodulatory effects were assessed by investigation of lymphocyte subsets, natural killer (NK) cell activity, phagocytic and oxidative activity of polymorphonuclear leukocytes, and antiviral activity of serum before and 1 week after treatment. Viscum album therapy resulted in normalization of initial immune indices either below or above the normal ranges. High levels of antiviral activity before treatment were significantly decreased by Viscum album mali. Viscum album treatment should be studied further in children with RRI.

Adolescent↗

Lectin-induced increase in clonogenic growth of haematopoietic progenitor cells.

The galactoside-specific plant lectin, Viscum album agglutinin (VAA-I) increases cellular parameters of natural host defence. It also binds to a variety of haematopoietic cells, including progenitors. We investigated whether VAA-I has a stimulatory effect on haematopoietic progenitor cells. Peripheral blood progenitor cells from 7 healthy volunteers were cultured in a colony assay with VAA-I plus erythropoietin (EPO) and stem cell factor (SCF). At 50 pg/ml VAA-I induced a significant increase in the cytokine-dependent clonogenic growth (52% in median, p < 0.05). In another set of experiments purified CD34+ cells were isolated from the bone marrow aspirate of 4 patients with non-metastatic breast cancer using fluorescence-activated cell sorting. Binding to CD34+ cells was demonstrated by using directly fluorescence-conjugated VAA-I. Co-incubation with D-galactose significantly abrogated this effect. CD34+ cells were cultured in the presence of EPO, SCF, interleukin-3, granulocyte/monocyte colony-stimulating factor and granulocyte colony-stimulating factor. VAA-I alone had no measurable effect on the clonogenic growth of the isolated cells. However, at concentrations of 100 and 250 pg/ml VAA-I increased the cytokine-dependent proliferation and differentiation of CD34+ cells by a median of 75 and 85%, respectively. The results show that VAA-I binds to haematopoietic progenitor cells and has a co-stimulatory effect on their proliferation.

Antigens, CD34↗

Study of the activity of differentiation-induction in a Chinese herb-viscum alniformosanae. Part 1: In vitro induction of differentiation in HL-60 leukemic cell line by conditioned medium secreted from viscum alniformosanae-stimulated mononuclear cells.

A conditioned medium(CM), designated as 572-CMF-, was a Chinese herb viscum alniformosanae (V.A.) stimulated mononuclear cells. This CM has the capacity to induce the promyelocytic cell line HL-60 to differentiate into morphologically and functionally mature monocytoid cells. However, our results on the effect of a combination of 572 conditioned medium and IFN-r, TNF and IL-2 were neither synergistic nor additive. Further investigation of the nature of this conditioned medium remains to be performed.

Cell Differentiation↗

Effect of a recombinant lectin, Viscum album agglutinin on the secretion of interleukin-12 in cultured human peripheral blood mononuclear cells and on NK-cell-mediated cytotoxicity of rat splenocytes in vitro and in vivo.

A plant lectin, Viscum album agglutinin-I (VAA-I) has been shown to increase the number and cytotoxic activity of natural killer (NK) cells in animal models, but the mechanisms underlying these effects are poorly understood. We investigated the effects of the recombinant form of this lectin (rVAA) on secretion of interleukin (IL)-12 and on NK-mediated cytotoxicity against K562 target cells in cultures of human peripheral blood mononuclear cells (PBMC) as well as against YAC-1 target cells in cultured rat spleen cells. In 24-hour cultures of PBMC, 10 ng/ml plant VAA-I and 50 ng/ml rVAA induced significant increases in the secretion of total IL-12. Its biologically active heterodimeric form, p70, was also significantly induced by rVAA. Preincubation of PBMC or splenocytes for 48 h with rVAA in concentrations ranging between 10 pg/ml and 100 pg/ml resulted in moderate enhancements of NK-mediated cytotoxicity. However, coincubation of a low dose of rVAA (100 pg/ml) together with IL-2 and IL-12 (60 U/ml and 2 U/ml, respectively) led to additive stimulation of NK activity. In in vivo experiments, rVAA showed an enhancing effect on NK activity with a bell-shaped curve of efficacy. Forty-eight hours after a single intravenous injection of its most effective doses, 0.5 and 1 ng/kg, into Wistar rats, the NK cytotoxicity of splenocytes against YAC-1 targets doubled, and the frequency of large granular lymphocytes in peripheral blood showed 2.1- and 3-fold increases as compared to control animals. Twenty-four hours following these low lectin doses, the number of large granular lymphocytes was also significantly elevated. After 48 h, 0.5 ng/kg rVAA induced a significant augmentation in the percentage of peripheral Mac-1+ mononuclear cells, including activated monocytes and NK cells. The present results suggest that rVAA augments the secretion of an active form of IL-12 and potentiates the cytokine-induced NK activation. These effects of rVAA may be related to its stimulatory effects on MHC-unrestricted cytotoxicity in vivo.

Adjuvants, Immunologic↗

No evidence of IFN-gamma increase in the serum of HIV-positive and healthy subjects after subcutaneous injection of a non-fermented viscum album L. extract.

Iscador, an aqueous extract of Viscum album L., has been used for more than 80 years as an anticancer drug. Due to its immunomodulatory potential, since the onset of the AIDS epidemic it has also been applied in the treatment of HIV-positive and AIDS patients in the form of the preparation V. album QuFrF (VaQuFrF; Labor Hiscia, Arlesheim, Switzerland). In in vitro investigations, incubation of peripheral blood mononuclear cells with V. album L. extracts resulted in stimulation of lymphocyte activity with increased gene expression and release of various cytokines and also of interferon gamma (IFN-gamma). In the latent phase, HIV positives exhibit only slightly elevated IFN-gamma concentrations in serum in comparison with HIV negatives, but in the acute phase of AIDS, there is an increase in levels of IFN-gamma. As the assay of cytokine levels in serum is a simple method of measuring immune system reactions, the aim of this trial was to determine whether increases in serum IFN-gamma levels in HIV positives and HIV negatives can be detected using this method after repeated injections of VaQuFrF. Five healthy subjects and 13 HIV-positive patients were investigated. IFN-gamma concentrations in serum were assayed using an ELISA test kit (ELISA test; ENDOGEN, Cambridge, Mass., USA). No drug-related elevation of serum IFN-gamma was observed at any time point during the trial. It can thus be concluded that this method is not suitable for direct investigation of the immunomodulatory effects of VaQuFrF in vivo.

Adjuvants, Immunologic↗