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Heart failure as an inflammatory condition: potential role for androgens as immune modulators.

Heart failure has traditionally been considered a disease of the myocardium, with symptoms arising from altered haemodynamics. However, it is now recognised that, in addition to marked neuroendocrine disturbance, there is perturbation of cytokine expression in patients with heart failure, resulting in an inflammatory imbalance. This not only influences symptoms, but also plays a central role in the underlying pathophysiological processes of heart failure, leading to disease progression and poorer prognosis. Recognition of the influence of cytokines, in particular tumour necrosis factor, has opened a new avenue for potential therapies for heart failure. Current approaches involve immunomodulation, aimed at suppressing tumour necrosis factor. We suggest that androgens may potentially offer a superior therapeutic strategy by their well-recognised non-specific immunosuppressive and anti-inflammatory effects. Studies of cell lines, human mononuclear cells and animals in vivo have demonstrated the 'anti-cytokine' actions of androgens, and we have found a similar action in whole blood from patients with heart failure. These effects, along with the anabolic action of these agents, make androgens an attractive potential option for treatment of patients with heart failure.

Androgens↗

Helicobacter pylori phase variation, immune modulation and gastric autoimmunity.

Helicobacter pylori can be regarded as a model pathogen for studying persistent colonization of humans. Phase-variable expression of Lewis blood-group antigens by H. pylori allows this microorganism to modulate the host T-helper-1-cell versus T-helper-2-cell response. We describe a model in which interactions between host lectins and pathogen carbohydrates facilitate asymptomatic persistence of H. pylori. This delicate balance, favourable for both the pathogen and the host, could lead to gastric autoimmunity in genetically susceptible individuals.

Amino Acid Sequence↗

Immune modulation in autologous bone marrow transplantation: cyclosporine and gamma-interferon trial.

From March 1994 to November 1994, 16 patients with high risk hematological malignancies were entered in a phase I clinical trial, designed to confirm the toxicity of cyclosporine and gamma interferon given to induce autologous graft-versus-host disease (GVHD) after autologous bone marrow transplantation (ABMT). This trial was based on the results in a rodent model, in which cyclosporine given after ABMT induces an autoimmune syndrome (autologous GVHD) identical to allogeneic GVHD. Further, this autologous GVHD is associated with a graft-versus-tumor effect augmented by interferon that upregulates MHC class II expression on normal and tumor cells, the target of the cytolytic T cells in autologous GVHD. In this trial, cyclosporine 1 mg/kg/day was given from the day of bone marrow reinfusion until the completion of the interferon and gamma-interferon. Gamma-interferon at 0.025 mg/m2 every other day was started when the total white cell count was >200 cells/ml for 2 consecutive days and continued for a total of 10 doses after ABMT. The preparative regimens were busulfan and cyclophosphamide, or cyclophosphamide with total body irradiation. All patients received 4HC-purged marrow grafts. Median age was 45 years (range 19-68). The diagnoses included chemo-resistant non-Hodgkin's lymphoma (10), acute lymphoblastic leukemia (two), chemo-resistant Hodgkin's disease (two), acute myeloid leukemia (one), and multiple myeloma (one). Median absolute neutrophil count recovery was 25.5 days (range 19-46 days). Median platelet count recovery was 40.5 days (range 28-279 days). There were nine deaths, two were related to transplant toxicity (infection), while the other seven were due to relapse. Event-free survival with a median of 964 days (range 19-1441 days of follow-up was 44%. In conclusion, treatment with cyclosporine, and gamma-interferon after ABMT was well tolerated and did not impair engraftment. Further studies with a larger number of patients are required to document any beneficial anti-tumor effect of autologous GVHD induction after ABMT.

Adolescent↗

Apolipoprotein E modulates immune activation by acting on the antigen-presenting cell.

Apolipoprotein E (ApoE) is synthesized by a variety of cells including macrophages. These cells activate T lymphocytes by antigen presentation, while the T-cell cytokine, interferon-gamma, inhibits macrophage ApoE expression. ApoE inhibits T-cell proliferation in culture but its role in immune responses has been unclear. The ApoE-deficient (E0) mouse permits an evaluation of the immunological role of ApoE. We have analysed T-cell responses to an exogenous antigen (ovalbumin) and polyclonal mitogen (concanavalin A) in E0 and ApoE+/+ mice. Macrophages of E0 mice stimulated T-cell activation more effectively as antigen-presenting cells than macrophages from ApoE+/+ mice. Both proliferation and interferon-gamma secretion were enhanced in T cells activated in the context of antigen-presenting cells from E0 mice. Since the macrophage-T-cell interaction depends on interactions between cell surface molecules, we assessed the expression of such molecules after in vivo stimulation with interferon-gamma. This treatment caused an increased expression of the co-stimulatory surface proteins CD40 and CD80, and also of the major histocompatibility complex class II molecules I-Ab on macrophages of E0 mice compared with ApoE+/+. Our data suggest that ApoE inhibits T-cell activation by reducing the density of immune stimulatory proteins on antigen-presenting cells.

Animals↗

Interleukin-10-treated dendritic cells modulate immune responses of naive and sensitized T cells in vivo.

Interleukin-10 is a pleiotropic cytokine known to have inhibitory effects on the accessory functions of dendritic cells. In vitro, interleukin-10 converts immature dendritic cells into tolerizing antigen- presenting cells. To assess whether interleukin-10-treated dendritic cells exert tolerizing effects in vivo, CD4+ T cells from DO11.10 ovalbumin-T cell receptor transgenic mice were transferred to syngeneic BALB/c recipients. Recipient animals were treated with ovalbumin-pulsed/unpulsed, interleukin-10-treated/untreated CD11c+ dendritic cells thereafter and ovalbumin-specific proliferation of lymph node cells was assessed by restimulation with the peptide in vitro. In prophylactic experiments, recipients received naive CD4+ DO11.10 T cells and were immunized with ovalbumin323-339 peptide in incomplete Freund's adjuvant after treatment with various subtypes of dendritic cells. Strong ovalbumin-specific proliferation was observed in animals immunized with control ovalbumin-dendritic cells. Minimal proliferation was found in mice treated with ovalbumin-pulsed, interleukin-10-treated dendritic cells. In therapeutic experiments, preactivated CD4+ DO11.10 T cells were transferred, and recipients were treated with dendritic cells as described. Ovalbumin-specific proliferation was strong in recipients treated with ovalbumin-dendritic cells. CD4+ T cell proliferation from ovalbumin-interleukin-10-dendritic cell treated animals was below background. When delayed type hypersensitivity reactions in the footpads of prophylactically or therapeutically vaccinated animals were tested, mice treated with ovalbumin-interleukin-10-dendritic cells showed no footpad swelling compared with controls. Rechallenge with the antigen in vitro and in vivo did not alter the inhibitory effect of interleukin-10-treated dendritic cells. Thus, interleukin-10-treated dendritic cells inhibit ovalbumin-specific immune responses in naive and sensitized mice.

Animals↗

[Perioperative immune modulation in renal cell carcinoma--review of the current situation].

Surgery and immunotherapy are the mainstay in the treatment of renal cell carcinoma. Surgery, however, is associated with considerable perioperative immunodysfunction. This immunodysfunction can be modulated by pretreatment with Interleukin-2 (IL-2), which appears to prolong tumour-specific survival. Perioperative immunomodulation could help close the therapeutic gap between neoadjuvant and adjuvant immunotherapy. This article reviews recent literature and presents original data of 63 patients.

Antineoplastic Agents↗

Brazilin modulates immune function mainly by augmenting T cell activity in halothane administered mice.

Previously we reported that brazilin, the main principle of Caesalpinia sappan, was able to improve the altered immune functions caused by halothane administration in mice. To elucidate the mechanisms of its immunomodulating activities, the effects of brazilin on the functions of T cells and splenic cellularity were investigated. Brazilin decreased splenic cellularity and IL-2 production which had been augmented in mice treated with halothane (21.5% in olive oil, 10 mmol/kg) for 4 consecutive days whereas the reduced expression of IL-2 receptors by ConA or standard IL-2 was increased by brazilin treatment. These data indicate that halothane induced a dysfunction of T cells resulting in abnormal immune responses and these altered immune functions might be improved mainly by affecting the function of T cells.

Animals↗

Attractin (DPPT-L), a member of the CUB family of cell adhesion and guidance proteins, is secreted by activated human T lymphocytes and modulates immune cell interactions.

Attractin is a normal human serum glycoprotein of 175 kDa that is rapidly expressed on activated T cells and released extracellularly after 48-72 hr. We have cloned attractin and find that, as in its natural serum form, it mediates the spreading of monocytes that become the focus for the clustering of nonproliferating T lymphocytes. There are two mRNA species with hematopoietic tissue-specific expression that code for a 134-kDa protein with a putative serine protease catalytic serine, four EGF-like motifs, a CUB domain, a C type lectin domain, and a domain homologous with the ligand-binding region of the common gamma cytokine chain. Except for the latter two domains, the overall structure shares high homology with the Caenorhabditis elegans F33C8.1 protein, suggesting that attractin has evolved new domains and functions in parallel with the development of cell-mediated immunity.

Amino Acid Sequence↗

(1-->3)-beta-D-glucan and endotoxin modulate immune response to inhaled allergen.

Exposure to dust may involve co-exposure to agents which are allergens, together with those which are pro-inflammatory. To study the effects of such a co-exposure, the humoral and inflammatory responses were studied in guinea pigs inhaling the T-cell-dependent antigen ovalbumin (OVA) and the inflammatory agents (1 --> 3)-beta-D-glucan and lipopolysaccharide (LPS). The effects were evaluated as inflammatory cells in the lung and serum antibodies to OVA. LPS caused a stimulation of the OVA-induced antibody production which was abolished by simultaneous exposure to (1 --> 3)-beta-D-glucan. An increase of eosinophils after OVA exposure was decreased by co-exposure to (1 --> 3)-beta-D-glucan. The results demonstrate a complex interaction between adaptive and innate immune mechanisms in the lung, determined by exposure to common contaminants in airborne dust.

Administration, Inhalation↗

Effect of whey protein to modulate immune response in children with atopic asthma.

BACKGROUND: Levels of glutathione (GSH) in antigen-presenting cells promote a T-helper type 2 (Th2) cytokine response in mice. We have previously demonstrated that we can increase intracellular GSH levels in healthy young adults using a whey-based oral supplement (HMS90). We hypothesized that such supplementation in children with atopic asthma, a Th2 cytokine disease, would improve lung function and decrease atopy. METHODS: Eleven children (six females, five males; mean+/-standard deviation age, 12.6+/-3.6 years; baseline forced expired volume in 1 sec (FEV1), 82.4+/-15.4%predicted), underwent spirometry, methacholine provocation testing, and blood analysis for serum IgE and lymphocyte GSH before and after 1 month of supplementation (10 g twice daily). RESULTS: Initially the IgE was 1689+/-1596 microg/l (normal range <or=240 microg/l) and lymphocyte GSH was 1.75+/-0.48 microM (normal range 1.55+/-0.33 microM). IgE significantly decreased to 1379+/-1329 microg/l (P < 0.05) following supplementation. Although no significant changes in lymphocyte GSH or FEV1 were found for the group as a whole, the two patients with significant increases in lymphocyte GSH concentrations were the only two to demonstrate reductions in methacholine provocation doses (provocative concentration causing a 20% fall in FEV1). CONCLUSIONS: These results suggest a modest impact of whey protein supplementation on the cytokine response in atopic asthma. Supplementation for longer periods, or with more potent whey-based supplements, currently under development, may prove more beneficial.

Adolescent↗

Mesenchymal stromal cells: Tissue repair and immune modulation.

BM-derived mesenchymal stromal cells (MSC) differentiate along the mesenchymal lineage to bone, fat and cartilage. In vitro, MSC induce little, if any, proliferation of allogeneic lymphocytes. MSC inhibit the proliferation of activated T cells and the formation of cytotoxic T cells. In vivo, they appear to have anti-inflammatory effects. Preliminary studies suggest that MSC preferentially home to damaged tissue and therefore have therapeutic potential. Possible clinical indications include therapy-resistant severe acute GvHD, treatment of rejection of organ allografts and autoimmune disorders.

Bone Marrow Cells↗

Immune modulator pidotimod decreases the in vitro expression of CD30 in peripheral blood mononuclear cells of atopic asthmatic and normal children.

Recurrent viral infections are frequently observed in children with atopic asthma. In this study we investigated the ability of the synthetic immunomodulator pidotimod to affect in vitro the phenotype and/or cytokine profile of blood cells in relation to atopic asthma. Peripheral blood mononuclear cells were isolated from 13 atopic asthmatic and 9 normal children and stimulated in culture with mitogen either in the presence or not of the drug. Expression of surface markers was evaluated by flow cytometry, and production of interleukin-4 and interferon-gamma was measured in supernatants. Pidotimod was able to down-regulate the expression of CD30 on cells from both atopic and normal subjects. Because CD30 has been associated with Th-2 cells, this observation supports the possibility of pidotimod being able to affect the Th-1/Th-2 balance in atopic asthma.

Asthma↗

Analysis of the env V3 sequences obtained from patients with HIV type 1 infection treated with the immune modulant agent tucaresol.

Tucaresol, a Schiff base-forming compound that is shown to enhance cytotoxic T cell responses and the production of type 1 cytokines, represents a potentially useful adjuvant factor for treating HIV-1 infection. We studied the effect of tucaresol on V3 sequences within the HIV-1 env region derived from patients with different virologic and immunologic features who were enrolled in a phase I/II randomized clinical trial. The sequence analysis of the env V3 region of the viruses at baseline has confirmed a genotypic pattern similar to a macrophagotropic virus model; we analyzed the follow-up sequences at week 16 of the protocol and did not observe any difference in the tropism determinants within the third variable fragment of the env region. The administration of tucaresol did not accelerate env V3 evolution thus preventing modifications of HIV-1 tropism over time.

Amino Acid Sequence↗