Analysis of the Biological Properties of Blood Plasma Protein with GcMAF Functional Activity.

The main problem related to the studies focusing on group-specific component protein-derived macrophage-activating factor (GcMAF) is the lack of clarity about changes occurring in different types of macrophages and related changes in their properties under the effect of GcMAF in various clinical conditions. We analyzed the antitumor therapeutic properties of GcMAF in a Lewis carcinoma model in two clinical conditions: untreated tumor lesion and tumor resorption after exposure to Karanahan therapy. GcMAF is formed during site-specific deglycosylation of vitamin D3 binding protein (DBP). DBP was obtained from the blood of healthy donors using affinity chromatography on a column with covalently bound actin. GcMAF-related factor (GcMAF-RF) was converted in a mixture with induced lymphocytes through the cellular enzymatic pathway. The obtained GcMAF-RF activates murine peritoneal macrophages (p < 0.05), induces functional properties of dendritic cells (p < 0.05) and promotes in vitro polarization of human M0 macrophages to M1 macrophages (p < 0.01). Treatment of whole blood cells with GcMAF-RF results in active production of both pro- and anti-inflammatory cytokines. It is shown that macrophage activation by GcMAF-RF is inhibited by tumor-secreted factors. In order to identify the specific antitumor effect of GcMAF-RF-activated macrophages, an approach to primary reduction of humoral suppressor activity of the tumor using the Karanahan therapy followed by macrophage activation in the tumor-associated stroma (TAS) was proposed. A prominent additive effect of GcMAF-RF, which enhances the primary immune response activation by the Karanahan therapy, was shown in the model of murine Lewis carcinoma. Inhibition of the suppressive effect of TAS is the main condition required for the manifestation of the antitumor effect of GcMAF-RF. When properly applied in combination with any chemotherapy, significantly reducing the humoral immune response at the advanced tumor site, GcMAF-RF is a promising antitumor therapeutic agent that additively destroys the pro-tumor properties of macrophages of the tumor stroma.

Elevated levels of dehydroepiandrosterone as a potential mechanism of dendritic cell impairment during pregnancy.

BACKGROUND: This study aimed to test the hypothesis that immune dysfunction and the increased risk of spontaneous abortion in pregnant women with hyperandrogenia (HA) are caused by the reduced tolerogenic potential of dendritic cells (DCs) that results from elevated levels of dehydroepiandrosterone sulfate (DHEAS). METHODS: The phenotypic and functional properties of monocyte-derived DCs generated from blood monocytes from non-pregnant women, women with a normal pregnancy, or pregnant women with HA, as well as the in vitro effects of DHEAS on DCs in healthy pregnant women were investigated. RESULTS: In a normal pregnancy, DCs were shown to be immature and are characterized by a reduced number of CD83(+) and CD25(+) DCs, the ability to stimulate type 2 T cell responses and to induce T cell apoptosis. By contrast, DCs from pregnant women with HA had a mature phenotype, were able to stimulate both type 1 (IFN-γ) and type 2 (IL-4) T cell responses, and were characterized by lower B7-H1 expression and cytotoxic activity against CD8(+) T cells. The addition of DHEAS to cultures of DCs from healthy pregnant women induced the maturation of DCs and increased their ability to activate type 1 T cell responses. CONCLUSION: Our data demonstrated the reduction in the tolerogenic potential of DCs from pregnant women with HA, and revealed new mechanisms involved in the hormonal regulation of DCs mediated by DHEAS.

Interferon alpha induces generation of semi-mature dendritic cells with high pro-inflammatory and cytotoxic potential.

Dendritic cell-based vaccines are considered as a new and promising immunotherapeutic approach for cancer treatment. However, the choice of optimal protocol of dendritic cell generation in vitro represents the major challenge. Here, we compared phenotype and functional characteristics of human monocyte-derived dendritic cells (DCs) generated in the presence of IL-4/GM-CSF (IL4-DCs) and IFNα/GM-CSF (IFN-DCs). We showed that IFN-DCs displayed semi-mature phenotype and expressed higher level of CD123, TNF-related apoptosis-inducing ligand (TRAIL) and B7-H1 molecules in comparison with IL4-DCs. LPS-stimulated IFN-DCs were characterized by greater production of Th1/pro-inflammatory (IFN-γ, IL-2, IL-1ß, TNF-α, IL-17), Тh2/anti-inflammatory cytokines (IL-10, IL-5), hematopoietic growth factors (G-CSF) and chemokines (MCP-1). These data indicated more pronounced ability of IFN-DCs to induce cellular immune response as well as humoral immune response compared to IL4-DCs. LPS-stimulated IFN-DCs possessed higher direct cytotoxic activity against TRAIL-sensitive tumor cell line Jurkat and similar cytotoxicity against TRAIL-resistant tumor HEp-2 cells. Besides, IFN-DCs and IL4-DCs equally induced apoptosis of activated CD4(+) and CD8(+) T cells. These results suggest that IFN-DCs can be used as potent cell-based curative therapies for individuals with cancer.

Cytotoxic activity of ex-vivo generated IFNα-induced monocyte-derived dendritic cells in brain glioma patients.

Recent studies have revealed that besides the important role in triggering the adoptive antitumor immunity, dendritic cells (DCs) possess direct cytotoxic antitumor activity. Here, we investigated brain glioma patient monocyte-derived DCs generated in the presence of IFNα and GM-CSF (IFN-DCs). These DCs were characterized by reduced cytotoxic activity against TRAIL-resistant HEp-2 cells. The impairment of DC cytotoxic function was observed mainly in high-grade glioma patients and associated with poor survival. The dysfunction of patient DC cytotoxicity was partially restored under in vitro pretreatment of DCs with double-stranded human DNA as well as rIL-2. In contrast to healthy donors, IFN-DCs in a part of high-grade glioma patients also failed to lyse primary autologous or allogeneic glioma cells. Our findings point to possible contribution of DC impairment in tumor pathogenesis in brain glioma and justify the necessity to evaluate and correct DC cytotoxic function when exploring DCs as cancer vaccines in glioma.

Cytotoxic activity of dendritic cells as a possible mechanism of negative regulation of T lymphocytes in pulmonary tuberculosis.

The PD-1/B7-H1-mediated induction of T cell apoptosis/anergy as a possible mechanism of immune response failure was studied in 76 patients with pulmonary tuberculosis (TB) with normal and low-proliferative response to antigens of M. tuberculosis (purified protein derivative (PPD)). It was revealed that dendritic cells (DCs), generated in vitro from patient blood monocytes with GM-CSF + IFN-α, were characterized by increased B7-H1 expression, upproduction of IL-10, and reducing of allostimulatory activity in mixed lymphocyte culture (MLC). Moreover, DCs of patients with TB were able to enhance T cell apoptosis and to block T-cell division in MLC. It was shown that neutralizing anti-PD1 antibodies significantly decreased the proapoptogenic/tolerogenic effect of DCs. Correlation analysis revealed a direct relationship between IL-10 production and level of B7-H1 expression in the general group of investigated patients. It was demonstrated that generation of healthy donor DCs in the presence of IL-10 led to an increase in the number of DCs-expressed B7-H1 molecule, DC proapoptogenic activity, and a decrease in their allostimulatory activity. Obviously, the revealed phenomenon of the PD-1/B7-H1-mediated pro-apoptogenic activity of DCs is clinically significant since the cytotoxic/tolerogenic potential of DCs is more pronounced in patients with PPD anergy.

Peripheral T Cell Apoptosis and Its Role in Generalized Bacterial Infections: A Minireview.

In the present review we have attempted to analyze recent findings concerning apoptosis of mature peripheral T cells. The great attention is made to the factors underlying resistance or sensitivity of mature T lymphocytes to activation-induced cell death. The role of preactivation and altered costimulation is discussed in this regard. Besides, the possible role of cytokines in the modulation of T cell apoptosis is emphasized. Particular attention is paid to the studies of apoptosis disorders in the pathogenesis of generalized bacterial infections. In this connection some own results are summarized as well. To characterize T cell death and its role in the pathogenesis of bacterial infections an anti-CD3-mAb or Con A-induced apoptosis in patients with severe and generalized forms of surgical infections have been investigated. We have found a significant increase of activation-induced lymphocyte apoptosis and a high level of apoptosis in freshly isolated lymphocytes in patients with surgical infections. Alternatively, peripheral blood mononuclear cells from surgical patients without infectious complications did not exhibit a marked enhancement of activation-induced cell death. Activation-induced T cell death in surgical infections appeared to be Fas-dependent, involved reactive oxygen intermediates and was partly prevented by pro-inflammatory cytokines, among which IL-2 exhibited the most pronounced anti-apoptotic activity. Likewise, APACHE II score, as a marker of the infection severity, directly correlated with a rate of activation-induced T cell apoptosis. Accelerated T cell apoptosis at the early stage of infection was revealed in survivors and non-survivors, that appears to designate a common pathway for the restriction of systemic inflammation. At the late stage of infection altered T cell apoptosis could account for different outcomes, since the patients with lethal outcome showed 2-fold increase in activation-induced cell death compared to the opposite group. Immunotherapy with rIL-2 declined anti-CD3-induced apoptosis and promoted a reduction in the mortality rate from 29% to 13%.

High-Dose Immunosupression and Stem Cell Transplantation in Severe Autoimmune Diseases.

High-dose chemotherapy followed by hematopoietic stem cell (SC) transplantation has been recently proposed as a new strategy for the treatment of severe autoimmune diseases. The rationale for using stem cell transplantation to treat autoimmune disease is based on the principle of complete ablation of an aberrant immune system followed by reconstitution of a new immune system deriving from graft. Three different approaches are being currently used: 1) allogeneic SC transplantation, 2) autologous SC rescue following "immunoablation", and 3) intensive immunosuppression alone. By October 2000, a total of 310 patients who received SC transplantation for autoimmune diseases were registered in the European Group for Blood and Marrow Transplantation/European League Against Rheumatism. Five patients with primary severe autoimmune diseases (4 female and 1 male) were enrolled in our Institute from 1998 to 2000. Transplantations were made for systemic lupus erythematosus (SLE, n = 4) and idiopathic thrombocytopenic purpura (ITP, n = 1). Three SLE patients had lupus nephritis, lung vasculitis with pulmonary hypertension, secondary antiphospholipide syndrome, 1 SLE patient had central nervous system involvement with paraplegia, patient with ITP had a relapse after splenectomy and had unresponsive severe thrombocytopenia. Follow up is now 24 months for 1 SLE patient (she is in complete remission), 12 months for the 2nd SLE patient (partial response), ITP patient is well at present, platelets >100 x 10(9), dose of prednisolone is 10 mg/day. 2 SLE patients died on day +11 and +19 due to transplant-associated complications (sepsis). The study is still ongoing and longer follow-up is necessary to assess long-term efficacy of this treatment approach.

T Cell Functional Disturbances in Patients with Pulmonary Tuberculosis.

The investigations of 38 patients with pulmonary tuberculosis (PT) revealed combined T cell and monocyte functional disturbances. Indeed, the percentages of CD4(+) and CD8(+) T lymphocytes, proliferative response and IL-2 production, as well as the percentages of HLA DR(+) monocytes and IL-1beta production were significantly decreased in PT patients as compared with normal individuals. Herewith the absolute T lymphocyte number did not undergo the pronounced changes. The decrease of T cell proliferative response was not mediated through immunosuppressive action of monocytes or T lymphocytes since removing of "adherent" cells from patient's peripheral blood mononuclear cells (PBMC) or pretreatment of PBMC with indomethacin and cyclophosphan failed to recover mitogenic reactivity in vitro. The patient's sera also did not significantly influence on PBMC proliferation. The decrease of IL-2 production and the stimulation of T cell proliferative response via TcR-CD3 complex, i.e. through the classic pathway of activation, indicated the anergy of T lymphocyte in tuberculosis patients. Furthermore, T lymphocytes were characterized by enhanced apoptosis. It should be noted, that patient's sera (especially in the patients with an initially high apoptosis) promoted significant anti-apoptotic activity. It is likely that this mechanism may be an explanation, why absolute T lymphopenia is absent during tuberculosis infection. Our findings suggest, that T lymphocyte dysfunctions in patients with PT are caused by impairments of T cell activation process, which lead to predominance of "negative" response (induction anergy, apoptosis) and to a lesser degree connected with direct suppressive mechanisms mediated by monocytes, T lymphocytes or serum factors.

Inflammatory Syndromes (SIRS, MARS, CARS) in Patients with Surgical Infection.

In the present study 37 patients with surgical infection were investigated and a new set of diagnostic tests for detection of major syndromes of systemic inflammation - systemic inflammatory response syndrome (SIRS), compensatory anti-inflammatory response syndrome (CARS) and mixed antagonist response syndrome (MARS) - was developed. In summary, we have demonstrated that patients with surgical infection were characterized by an immunodeficiency with significant reduction of mitogen-induced proliferation and IL-2/IL-4 production in vitro combined with decrease of HLA DR(+) monocytes. Furthermore, it was revealed that the patient's serum exhibited substantially enhanced suppressive and inflammatory activities as well as the level of C-reactive protein. We have defined the negative correlation between the serum inflammatory and suppressive activities (SIA and SSA) that was most prominent at the early stage of disease. Since the changes of serum bioactivity in the course of surgical infection were prominent and coherent, we supposed that tested activities might reflect the distinctive features of systemic inflammation. In according to this assumption, the patients were divided into 3 subgroups with predominance of SIRS, CARS and MARS by using the SIA and SSA expression. It has been shown that SIRS was more frequently detected at the early stage, whereas CARS - at the late stage of disease. Patients with SIRS, CARS or MARS significantly differed by the content of CD8(+) T and CD72(+) B lymphocytes, the concentration of IgG and IgA, the production of IL-2 and IL-4. Finally, the data obtained from patients, those were studied repeatedly, showed the possibility of transformation of the major systemic inflammatory syndromes during the disease course. Our findings suggest that measurement of serum inflammatory and suppressive activities may help to differentiate patients with SIRS, CARS or MARS and to select the appropriate strategy of immunotherapy.