Search

Tumor growth and expansion are determined by the immunological tumor microenvironment (TME). Typically, early tumorigenic stages are characterized by the immune system not responding or weakly responding to the tumor. However, subsequent tumorigenic stages witness the tumor promoting its growth and metastasis by stimulating tumor-protective (pro-tumor) inflammation to suppress anti-tumor immune responses. Here, we propose the pivotal role of inflammation control in a successful anti-cancer immunotherapy strategy, implying that available and novel immunotherapeutic modalities such as inflammation modulation, antibody (Ab)-based immunostimulation, drug-mediated immunomodulation, cancer vaccination as well as adoptive cell immunotherapy and donor leucocyte transfusion could be applied in cancer patients in a synergistic manner to amplify each other's clinical effects and achieve robust anti-tumor immune reactivity. In addition, the anti-tumor effects of immunotherapy could be enhanced by thermal and/or oxygen therapy. Herein, combined immune-based therapy could prove to be beneficial for patients with advanced cancers, as aiming to provide long-term tumor cell/mass dormancy by restraining compensatory proliferation of surviving cancer cells observed after traditional anti-cancer interventions such as surgery, radiotherapy, and metronomic (low-dose) chemotherapy. We propose the Inflammatory Prognostic Score based on the blood levels of C-reactive protein and lactate dehydrogenase as well as the neutrophil-to-lymphocyte ratio to effectively monitor the effectiveness of comprehensive anti-cancer treatment.

To date, the association of an imbalance of the intestinal microbiota with various human diseases, including both diseases of the gastrointestinal tract and disorders of the immune system, has been shown. However, despite the huge amount of accumulated data, many key questions still remain unanswered. Given limited data on the composition of the gut microbiota in patients with ulcerative colitis (UC) and irritable bowel syndrome (IBS) from different parts of Siberia, as well as the lack of data on the gut microbiota of patients with bronchial asthma (BA), the aim of the study was to assess the biodiversity of the gut microbiota of patients with IBS, UC and BA in comparison with those of healthy volunteers (HV). In this study, a comparative assessment of the biodiversity and taxonomic structure of gut microbiome was conducted based on the sequencing of 16S rRNA genes obtained from fecal samples of patients with IBS, UC, BA and volunteers. Sequences of the Firmicutes and Bacteroidetes types dominated in all samples studied. The third most common in all samples were sequences of the Proteobacteria type, which contains pathogenic and opportunistic bacteria. Sequences of the Actinobacteria type were, on average, the fourth most common. The results showed the presence of dysbiosis in the samples from patients compared to the sample from HVs. The ratio of Firmicutes/Bacteroidetes was lower in the IBS and UC samples than in HV and higher the BA samples. In the samples from patients with intestinal diseases (IBS and UC), an increase in the proportion of sequences of the Bacteroidetes type and a decrease in the proportion of sequences of the Clostridia class, as well as the Ruminococcaceae, but not Erysipelotrichaceae family, were found. The IBS, UC, and BA samples had signif icantly more Proteobacteria sequences, including Methylobacterium, Sphingomonas, Parasutterella, Halomonas, Vibrio, as well as Escherichia spp. and Shigella spp. In the gut microbiota of adults with BA, a decrease in the proportion of Roseburia, Lachnospira, Veillonella sequences was detected, but the share of Faecalibacterium and Lactobacillus sequences was the same as in healthy individuals. A signif icant increase in the proportion of Halomonas and Vibrio sequences in the gut microbiota in patients with BA has been described for the f irst time., (Copyright © AUTHORS.)

c-Jun N-terminal kinase (JNK) is a critical mitogen activated protein kinase (MAPK) implicated in inflammatory processes, with IQ-1S (11H-indeno[1,2-b]quinoxalin-11-one oxime sodium salt) being a high-affinity JNK inhibitor with pronounced anti-inflammatory properties. Here, we studied direct effects of IQ-1S on phenotypical and cytokine-producing characteristics of activated human monocytes/macrophages and T cells in vitro. Purified monocyte/macrophage cells were activated by bacterial lipopolysaccharide (LPS, 1 μg/ml) for 24 h, while T cells were activated by particles conjugated with antibodies (Abs) against human CD2, CD3, and CD28 for 48 h. Treatment with IQ-1S (0.5-25 μМ) in the presence of LPS reduced percentages of CD197 (CCR7)-positive cells in macrophage cultures, without affecting CD16 + (FcγRIII, low-affinity Fc-receptor), CD119 + (interferon-γ receptor 1), and CD124 + (IL-4 receptor α-subunit) cells. In addition, IQ-1S reduced production of tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and IL-10 in macrophage cultures. In activated T cell cultures, IQ-1S decreased CD25 + cell numbers in both CD4-positive and CD4-negative T cell compartments. Central memory СD45RA - /СD197 + and effector memory СD45RA - /СD197 - T cells were more sensitive to IQ-1S-mediated suppression, as compared to naïve СD45RA + /СD197 + and terminally-differentiated effector СD45RA + /СD197 - T cells. IQ-1S also suppressed T-cell cytokine production (IL-2, interferon-ɣ, IL-4, and IL-10). Collectively, the results suggest that both human macrophage and T cells could be immediate cell targets for IQ-1S-based anti-inflammatory immunotherapy. IQ-1S-mediated suppressive effects were unlikely to be associated with macrophage/T helper polariation., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

We studied direct effects of human granulocyte colony-stimulating factor (G-CSF) on phenotypical properties of human macrophage cells in vitro . CD14 + monocyte/macrophages (Mc/Mphs) were isolated from blood of healthy donors by positive magnetic separation. G-CSF (0.01-1.0 ng/mL), when added to Mc/Mphs along with lipopolysaccharide (LPS, 1.0 μg/mL), was able to noticeably reduce proportions of CD119 (interferon-γ receptor 1)-positive cells, with no stable effects on CD16 (FcγRIII) + and СD124 (IL-4 receptor subunit alpha)-positive cells. In addition, G-CSF markedly upregulated IL-6 production by LPS-activated Mph cells, without significantly affecting IL-1β, IL-10 and tumor necrosis factor-α (TNF-α) secretion. Our data suggests that G-CSF could restrain Mph polarization to pro-inflammatory (M1) phenotype, thus potentially supporting pro-regenerative Mph activity with implications for immunotherapeutic interventions.

Introduction : Pathogenic memory CD4 + T cells are the mainspring of autoimmune and allergic disorders, suggesting that effective pathogenetic immunotherapy should be primarily directed onto their direct inactivation without affecting normal cells. Areas covered : A novel immunotherapeutic concept is proposed that applies suboptimal doses of several cytotoxic antibodies (Abs) against membrane antigens (Ags) (such as CD4, СD45RO, СD69, CD103, CD27, CD38, DR, etc.) with a view to achieve a threshold density of immune complexes on pathogenic memory CD4 + T cells for their selective elimination. During disease exacerbations, a complex Ab formulation could be applied to combine Abs against CD4, СD45RO, and СD69 to selectively destroy both activated memory CD4 + T cells located in lymphoid tissues and resident memory CD4 + T cells present in local inflammatory sites in situ. In contrast, normal T cells are spared from destruction as being recognized only by some Abs leading to Ab-Ag complexes below cytolytic threshold levels. Inactivation of pathogenic CD4 + T cells will also withdraw T helper support to pathogenic memory B cells and memory CD8 + T cells, thus effectively diminishing their activity. Expert opinion : The described approach benefits from universality and potential availability of a vast library of monoclonal Abs with relevant specificity.

Background : We studied direct effects of human granulocyte-macrophage colony stimulating factor (GM-CSF) on phenotypical characteristics and cytokine-production of non-activated and activated human monocytes/macrophages (Mc/Mphs) and T cells. Methods : Purified Mc/Mphs were activated by bacterial lipopolysaccharide (LPS, 1 μg/ml) for 24 h, while T cells were activated by particles conjugated and antibodies (Abs) against human CD2, CD3, and CD28 for 48 h. Results : GM-CSF treatment (0.01-10 ng/ml) was shown to reduce percentages of CD197 (CCR7)-positive cells in non-activated Mph cultures, without affecting significantly CD14 + (LPS co-receptor), CD16 + (FcγRIII, low-affinity Fc-receptor), CD119 + (interferon-gamma receptor 1), and CD124 + (IL4 receptor α-subunit) cells. In addition, GM-CSF reduced relative numbers of CD197 + cells, as well as CD14 + , CD16 + , and CD119 + cells in activated Mph cultures without affecting CD124 + cell distribution. GM-CSF at the highest dose of 10 ng/ml enhanced TNF-α and IL-6 (but not IL-1β and IL-10) production in activated Mc/Mphs. In activated T cell cultures, GM-CSF at 0.1-1.0 ng/ml augmented CD38 + cell numbers in naïve СD45RA + /СD197 + and central memory СD45RA - /СD197 + cell subsets, with no effect on effector СD45RA - /СD197 - and terminally differentiated effector СD45RA + /СD197 - cells. GM-CSF at a low dose (0.01 ng/ml) down-regulated INF-γ production, while at a high dosage (10.0 ng/ml) up-regulated IL-2 and IL-4 production. Conclusion : In general, the results suggest that GM-CSF is able to facilitate the implication of both Mph and T cells in the adaptive immunogenesis.

We propose a novel immunotherapeutic paradigm that justifies application of several antibodies to various membrane-associated antigens to achieve a critical threshold density of immune complexes on the surface of cancer cells sufficient for triggering downstream cytolytic pathways. Indeed, some cancer-associated antigens (such as cancer/testis antigens) were found to be expressed on many cancer (but not normal) cells, with their baseline membrane expression levels being originally quite low for some of them, or even further down-regulated due to immune-driven cell selection. To achieve the mandatory threshold density of membrane-associated immune complexes on malignant cells, the concept stipulates combined application of antibodies specific for a cancer-associated antigen along with antibodies against an antigen expressed not only on tumor, but also on normal cells. In the proposed scenario it is of vital importance that the latter antibodies should be applied in suboptimal dosage to exclude the destruction of normal cells devoid of a cancer-associated antigen. Malignant cells often co-express antigens not present concurrently on normal cells at high levels. In such cases, suboptimal dosages of antibodies specific for those antigens could also be applied to achieve cumulative effect leading to selective destruction of tumour cells. Hence, the described immunotherapeutic technology could be used metaphorically speaking as a kind of 'immunological knife', which is capable of highly selective destruction of cancer cells without destroying normal cells., Competing Interests: CONFLICTS OF INTEREST The authors have no conflicts of interest to disclose.

We investigated the direct effects of human granulocyte colony-stimulating factor (G-CSF) on functionality of human T-cell subsets. CD3 + T-lymphocytes were isolated from blood of healthy donors by positive magnetic separation. T cell activation with particles conjugated with antibodies (Abs) to human CD3, CD28 and CD2 molecules increased the proportion of cells expressing G-CSF receptor (G-CSFR, CD114) in all T cell subpopulations studied (CD45RA + /CD197 + naive T cells, CD45RA - /CD197 + central memory T cells, CD45RA - /CD197 - effector memory T cells and CD45RA + /CD197 - terminally differentiated effector T cells). Upon T-cell activation in vitro, G-CSF (10.0 ng/ml) significantly and specifically enhanced the proportion of CD114 + T cells in central memory CD4 + T cell compartment. A dilution series of G-CSF (range, 0.1-10.0 ng/ml) was tested, with no effect on the expression of CD25 (interleukin-2 receptor α-chain) on activated T cells. Meanwhile, G-CSF treatment enhanced the proportion of CD38 + T cells in CD4 + naïve T cell, effector memory T cell and terminally differentiated effector T cell subsets, as well as in CD4 - central memory T cells and terminally differentiated effector T cells. G-CSF did not affect IL-2 production by T cells; relatively low concentrations of G-CSF down-regulated INF-γ production, while high concentrations of this cytokine up-regulated IL-4 production in activated T cells. The data obtained suggests that G-CSF could play a significant role both in preventing the development of excessive and potentially damaging inflammatory reactivity, and in constraining the expansion of potentially cytodestructive T cells., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Interleukin-8 (IL-8, CXCL8) belongs to major chemokines to stimulate migration of neutrophils and monocytes/macrophages (Mc/Mphs) into the inflammation sites. We studied the direct effects of IL-8 on the functionality of human Mc/Mphs in vitro. CD14-positive cells were isolated from human peripheral blood mononuclear cells (PBMCs) by positive magnetic separation and were further cultured with or without lipopolysaccharide (LPS, 1.0 μg/ml) for 24 h. We showed that upon LPS activation of Mc/Mphs, IL-8 reduced markedly both the percentages and median fluorescence intensity (MFI) of CD16 (FcγRIII)-positive cells among CD14 high cells, as well as in cells that reduced the expression of СD14 during their culturing. IL-8 was also found to be capable of reducing the expression of СD124 (IL-4 receptor subunit alpha, IL-4RA), with concomitant enhancement of the expression of both CD119 (interferon-gamma receptor 1) and CD197 (CCR7) in Mph cells. In addition, IL-8 up-regulated production of IL-6 and IL-1β [but not tumor necrosis factor-α (TNF-α) and IL-10] by activated Mc/Mphs. Our results suggest the ability for IL-8 to directly favor pro-inflammatory M1-type Mph activity., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objective: We studied direct effects of Erythropoietin (Epo) on functional properties of human monocytes/macrophages (Mc/Mphs) in vitro., Methods: Cells expressing CD14 marker were isolated from human peripheral blood mononuclear cells (PBMCs) by positive magnetic separation. Mc/Mphs were cultured without or with bacterial lipopolysaccharide (LPS) in the absence or presence of Epo for 24 h., Results: We showed that Epo treatment hoticeably reduces the percentages of CD14+ cells, CD124 (alpha subunit of IL-4 receptor)+ cells and CD197 (CCR7)+ cells in non-activated Mph cultures without affecting the levels of CD16 (low-affinity Fc-receptor)+ and CD119 (interferon-γ (IFN-γ) receptor)+ cells. Epo also markedly reduced percentages of CD197+ cells in LPS-activated Mc/Mphs, without significantly affecting the expression of all other molecular markers studied. In addition, Epo caused moderate up-regulation of interleukin-1β (IL-1β) and IL-6 production in resting Mc/Mph cultures, as compared to the down-regulation of IL-1β and IL-6 production in LPS-activated cells. No Epomediated effects on tumor necrosis factor-α (TNF-α) and IL-10 production were observed., Conclusion: Our data suggests that Epo effects on Mph functionality are largely dependent on the baseline activation status of these cells, and that Epo exerts no distinct direct effects on the particular Mph polarization pathway., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

CD3 + T-lymphocytes were isolated from the normal donors by positive magnetic separation. Activation of the T cells with particles conjugated with antibodies to CD3, СD28 and СD2 molecules led to a marked increase in T-cell production of interleukine-8 (IL-8). We present evidence that IL-8 receptor α-chain (CXCR1, CD181) is expressed on the cell surface of 13.3% T cells. Activation of T-lymphocytes resulted in significant enhancement of CD181 + cells both in naive CD4 + T cell and terminally differentiated effector CD4 + T cell compartments with concomitant reduction of CD181 + cells in effector memory CD4 + T cell subset. The level of T cell activation was assessed judging from the surface expression of CD25 (IL-2 receptor α-chain). We demonstrate that IL-8 treatment (0.01-10.0ng/ml concentration range) reduced the activation status of both CD4 - and CD4 + effector memory T cells, as well as terminally differentiated effector T cells, without significantly affecting the activation of naive T cells or central memory T cells. In addition, IL-8 up-regulated IL-2 and down-regulated IL-10 production by activated T cells, with no effect on interferon-gamma (IFN-γ) and IL-4 production. Data obtained suggests the importance of IL-8 in the direct regulation of adaptive T cell reactivity., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Variable regions of both B-cell receptors (BCRs) and T-cell receptors (TCRs) are completely formed in the postnatal period, and, consequently, no innate immune tolerance against these structures exists in adulthood. Indeed, antibodies (Abs) specific to TCRs have been found in both animals and humans. These facts clearly indicate the existence of B cells able to directly interact with T cells through binding of BCRs to TCRs without implicating major histocompatibility complex molecules. A novel paradigm is proposed in that the immune memory is based on idiotype/anti-idiotype interactions occurring between BCRs and TCRs following clearance of the antigen that elicited immune responses. It is envisaged that direct contact between memory T and B cells could provide co-stimulatory signals needed to sustain viability, growth, and differentiation of the interacting immune cells. In contrast, plasma cells originating from memory B-cells could produce anti-TCR Abs that inhibit direct BCR-to-TCR interactions, thereby downregulating the B- to T-cell contact-based immune memory via a negative feedback mechanism.

The overall objective of disease management in autoimmune diseases is to suppress chronic inflammation and prevent organ damage. Therapies often revolve around five drug classes: non-steroidal anti-inflammatory drugs (NSAIDS), anti-malarials, steroids, immunosuppressants, and bio-therapies. However, none of these is a 'cure' and each displays a potential for adverse events. In particular, while all of them suppress harmful autoimmune responses, they also impact on useful protective immune responses. T-Cell receptor (TCR) immunogenicity provides a rationale for T-cell vaccinations to induce anti-idiotypic immune responses with the purpose of down-regulating functionality of idiotype-bearing self-reactive T-cells. To explore this, in this study, 39 patients with progressive (chronic) multiple sclerosis (MS) were multiply immunized with autological polyclonal T-cell vaccines (TCVs). None of the TCV-treated patients experienced any significant side-effects during the entire follow-up period (2 years). T-Cell vaccination had no significant effects on T-cell sub-population contents in the blood of MS patients after 2 years of immunotherapy initiation. However, a substantial reduction in the frequency of CD4 +  and CD8 +  memory T-cells able to produce interferon (IFN)-γ following activation were noted in the blood of TCV-treated patients. Moreover, significant and sustained reduction in plasma IFNγ levels and concomitant increases in interleukin (IL)-4 levels were documented in these samples. The TCV-treated subjects, however, exhibited no significant changes in plasma IL-17 and IL-18. More importantly was a significant decline in proliferative T-cell responses to myelin antigens in the TCV-treated patients, indicating attenuation of myelin-specific T-cell activity. Collectively, the results suggest that polyclonal T-cell vaccination is safe to use, able to induce measurable, long-lasting, anti-inflammatory immune effects in patients with advanced MS.

An accumulating body of evidence suggests that xenogeneic vaccines can be very effective in breaking the immune tolerance to human tumor-associated antigens (TAAs). We assessed adverse effects, as well as clinical and immune responses induced by a lyophilized xenogeneic polyantigenic vaccine (XPV) prepared from murine melanoma B16 and carcinoma LLC cells in 60 stage IV colorectal cancer patients. Neither grade III/IV toxicities, nor laboratory and clinical signs of systemic severe autoimmune disorders were documented in any XPV-treated patient. Clinical effects of various grades (complete response, partial response and disease stabilization) with duration of no shorter than 6 months was observed in 25 (41.67%) vaccinated patients. The average survival time of the XPV-treated patients was markedly longer than that of the clinically matched control patients (20 vs. 7 months). The overall 3-year survival rate in the XPV-treated and control group was 16.7% (10 patients) and 0%, respectively. Following a course of ten XPV vaccinations, peripheral blood mononuclear cell (PBMC) proliferation assays revealed increased T-cell immune responses to human Caco-2 colon adenocarcinoma-associated antigens. In addition, relative contents of CD25+ FoxP3+regulatory T-cells in patients with proven immunotherapy-mediated clinical effects (responders) were significantly decreased in the blood, which was paralleled by marked increases in serum levels of proinflammatory cytokines, such as interferon-alpha (IFN-α), IFN-ɣ, and interleukin-8 (IL-8). Serum levels of tumor necrosis factor-alpha (TNF-α), IL-1, IL-4, and IL-6 were not affected in both responder and non-responder patients. In conclusion, this study provides evidence for the safety, clinical feasibility and immunogenicity of xenogeneic composite cell vaccine administration in colorectal cancer patients. This is the first demonstration that clinical effects of such a vaccine are associated with vaccine-induced, proinflammatory immune responses., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

New therapies for melanoma have yielded promising results, but their application is limited because of serious side-effects and only moderate impact on patient survival. Vaccine therapies may offer some hope by targeting tumor-specific responses, considering the immunogenic nature of melanomas. To investigate the safety profile and efficiency of a xenogeneic cell-based vaccine therapy in stage III melanoma patients and evaluate the survival rate in treated patients. Twenty-seven stage III melanoma patients were immunized with a lyophilized xenogeneic polyantigenic vaccine (XPV) prepared from murine melanoma B16 and carcinoma LLC cells. Neither grade III/IV toxicities, nor clinically significant changes in blood and biochemical parameters were noted after an induction course of 10 XPV subcutaneous immunizations. No laboratory or clinical signs of systemic autoimmunity were documented. Following 10 vaccinations, a relative increase in the numbers of circulating memory CD4+CD45RO+ T cells (but not CD8+ CD45RO+ T cells) was observed. Peripheral blood mononuclear cells obtained from XPV-treated patients demonstrated increased proliferative responses to human BRO melanoma-associated antigens and marked increases in serum levels of IFN-γ and IL-8. Serum levels of TNF-α, IL-4 and IL-6 were not affected. The overall five-year survival rate in the treated patients was significantly higher than that in 27 control patients with matched clinical and prognostic characteristics (55% vs 18%). XPV-based immunotherapy could be maximally effective when started as early as possible before or after surgical excision of the primary tumor and local metastases, i.e. when tumor-mediated suppressive effects on immunity are minimal.

Anti-cancer vaccination is a useful strategy to elicit antitumor immune responses, while overcoming immunosuppressive mechanisms. Whole tumor cells or lysates derived thereof hold more promise as cancer vaccines than individual tumor-associated antigens (TAAs), because vaccinal cells can elicit immune responses to multiple TAAs. Cancer cell-based vaccines can be autologous, allogeneic or xenogeneic. Clinical use of xenogeneic vaccines is advantageous in that they can be most effective in breaking the preexisting immune tolerance to TAAs. An attractive protocol would be to combine vaccinations with immunostimulating and/or immunosuppression-blocking modalities. It is reasonable to anticipate that combined immunotherapeutic strategies will allow for substantial improvements in clinical outcomes in the near future., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

The immune system has been shown to be involved in not only the host defense against infectious pathogens but also in tissue repair processes continuously occurring in the body. Our review presents the hypothesis about the mechanism of TLR-mediated regulation of adaptive immune responses linked to the tissue destruction. In our opinion following injury to a tissue, the expression of tissue-specific determinant/MHC class II complexes on dendritic cells and macrophages are upregulated significantly due to the increased uptake of tissue debris. Consequently, T-cells become activated as a result of low affinity, but high avidity interactions between self-reactive CD4+T cells and antigen-presenting cells (APCs). The type of self antigen-induced immune responses depends on the multiple downstream signals generated by intracellular toll-like receptors (TLRs) 3, 7, 8, and 9, that discriminate "self" and "non-self" nucleic acids. Accumulating data suggest that ligation of intracellular TLRs by endogenous DNA/RNA released from necrotic cells may result in developing Th2-like responses, as well as in the alternative activation of macrophages (M2), that favor local tissue protection and compensatory cell growth. In contrast, ligation of intracellular TLRs by exogenous pathogen-derived DNA/RNA may promote Th1-driven responses, as well as classical activation of macrophages (M1), that contribute to local tissue destruction and suppress cell growth. We suggest here that the balance between the host- and pathogen-derived nucleic acids interacting with intracellular TLRs contributes to the balance between immune-mediated tissue-protective and tissue-destructive events occurring in the body., (Copyright © 2011 Elsevier GmbH. All rights reserved.)

We studied the expression of isoforms of stem cells factor mRNA forming as a result of alternative splicing. Both isoforms of stem cell factor mRNA forming as a result of alternative splicing were found in different fetal tissues. Changes in the expression of alternative isoforms of stem cell factor in peripheral blood mononuclear cells were demonstrated from the prenatal and neonatal periods to adult organism.

We analyzed delayed effects of transplantation of nervous and hemopoietic fetal cells to patients with consequences of spinal trauma. A decrease in neurological deficit associated with pronounced improvement of functional independence was observed in 48.9% cases. The best results were observed in patients receiving cell transplantation within the first 2 years after trauma and in younger individuals. The pattern of morphological changes in the spinal cord at site of injury, severity of damage, and the method of transplantation had no appreciable effects on its delayed results.

The expression of leukemia-inhibitory factor mRNA in human fetal tissues and mononuclear cells was studied during ontogeny. The expression of mRNA isoforms for leukemia-inhibitory factor was tissue-specific at the stage of prenatal development. The transition from antenatal and neonatal development to the postnatal period was accompanied by a decrease in the expression of mRNA isoforms for leukemia-inhibitory factor in mononuclear cells.

Patients with different forms of multiple sclerosis were treated with a vaccine consisting of myelin-reactive T cells. It was found that after this treatment, lymphocytes from patients acquired the capacity to generate antiidiotypic proliferative response directed towards myelin-reactive T cells. The serum concentration of IFN-gamma decreased about 2-fold 1.5-2.0 years after the start of vaccine therapy, whereas the concentration of IL-4 increased 2-3 fold. Myelin-reactive proliferative activity of peripheral blood mononuclear cells also decreased. The results of the 2-year follow-up study revealed no side effect of T-cell vaccination in patients with cerebrospinal form of multiple sclerosis and demonstrated its possible clinical efficiency in the treatment of this disease at early stages.

Two-staged technology for obtaining polyclonal T cell vaccine intended for the treatment of rheumatoid arthritis is described. Stage 1 includes antigen-dependent cultural selection of patient's T cells and stage 2 consists in their reproduction in the needed amounts by nonspecific mitogenic stimulation. T cell vaccination induces an effective specific anti-idiotypic immune response against T cells reactive to joint antigens. Vaccine therapy significantly reduces plasma level of IFN-gamma and increases IL-4 level. The results indicate immunological efficiency and safety of polyclonal T cell vaccine in patients with rheumatoid arthritis.

The objectives of this phase I-II trial were to assess the toxicity, immunological and clinical responses induced in 37 patients with stage IV colorectal cancer by the subcutaneous administration of a xenogenic polyantigenic vaccine (XPV) prepared from disrupted murine melanoma (B16) and carcinoma (LLC) cells. An inducing course of vaccinotherapy consisted of 10 immunizations (5 at weekly and 5 at fortnight intervals). Twenty-four hours later each of first 5 vaccinations the patient was subcutaneously given a low dose of the recombinant interleukin-2 (IL-2). A consolidating course of vaccinotherapy consisted of monthly vaccinations. No grade III or IV toxicities, but also laboratory and clinical signs of developing systemic autoimmune disorders were noted in any XPV-treated patient. A significant increase in cell-mediated immunoreactivity to both LLC and B16 antigens (Ags) occurred in the patients after inducing vaccinations, as determined by delayed-type hypersensitivity (DTH) skin reactions, as well as by blood lymphocyte proliferation responses. Vaccinations also led to increased cell-mediated reactivity to murine non-tumor, spleen cell (SC)-associated Ags. This reactivity, however, was not as significant as that to tumor-associated antigens (TAAs). XPV was also found to capable of generating IgG antibody-mediated responses. With immunotherapy concentrations of both interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) detectably elevated in patients' sera, suggesting intensification of T helper 1-/T helper 2-mediated responses in the XPV-treated patients. The average survival of the XPV-treated patients was noticeably superior than was that of the clinically comparable control patients (17 vs 7 months). Collectively the results suggest that xenogenic TAAs are safe to use, able to induce measurable cellular and humoral immune responses, and may be clinically effective in certain colorectal cancer patients.

The objectives of this phase I-II trial were to assess the toxicity, immunological and clinical responses induced in stage III/IV melanoma patients by the subcutaneous administration of xenogenic polyantigenic vaccine (XPV) prepared from disrupted murine melanoma (B16) and carcinoma (LLC) cells. An inducing course of vaccinotherapy consisted of ten immunizations (five at weekly and five at fortnight intervals). Twenty-four hours following each of the first five vaccinations, the patient was subcutaneously given a low dose of the recombinant interleukin-2 (IL-2). A consolidating course of the vaccinotherapy consisted of monthly vaccinations. Grade 3 or 4 toxicities, as well as laboratory and clinical signs of developing autoimmune disorders, were recorded in none of the 40 XPV-treated evaluable patients. A significant increase in delayed-type hypersensitivity (DTH) skin reaction to vaccinal B16, but not to LLC antigens (Ags), occurred in patients after inducing vaccinations. At the same time, those patients demonstrated a marked augmentation of blood lymphocyte proliferation responses not only to B16 but also to LLC Ags. Vaccinations also led to increased cell-mediated reactivity to murine non-tumor, spleen cell (SC)-associated Ags, which, however, was not as significant as that to tumor-associated antigens (TAAs). Of great importance was the fact that XPV administration resulted in increased blood lymphocyte proliferative reactivity of patients to human melanoma-associated Ags, while not affecting their reactivity to the control alloantigens. With immunotherapy, concentrations of both interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) were elevated in patients' sera, suggesting an intensification of the T helper1/ T helper 2-mediated responses in the XPV-treated patients. The average survival of the 32 stage IV melanoma XPV-treated evaluable patients was noticeably higher than that of the 32 clinically comparable control patients (13 vs. 5 months). The overall 3 year-survival rate in the XPV-treated group and the control group was 25% (8 patients) and 3% (1 patient), respectively. In general, the results suggest that xenogenic tumor cells may provide a novel feasible approach to constructing clinically effective vaccines.

We demonstrated that liquor from adult humans can maintain proliferative activity of cells of immature nervous tissue in vitro. The paper presents the results of a retrospective clinical study of the efficiency of cell therapy in the treatment of II-III degree comatose patients with severe brain injury. Cell suspension consisting of cells derived from immature nervous and hemopoietic tissues was injected into the recipient subarachnoidal space through a cerebrospinal puncture. The mortality in the study group was 8% vs. 56% in the control group. The 1.5-year follow-up demonstrated significantly better quality of life in patients receiving cell therapy in comparison with patients of the control group. Cell therapy proved to be ineffective for patients in a comatose state caused by hypoxic encephalopathy. The study demonstrated the efficiency of cell therapy in patients with severe brain injury during the acute period of the disease.

Cell suspension consisting of cells from immature nervous and hemopoietic tissues was transplanted subarachnoidally to patients with craniocerebral injury aftereffects. In some patients cell therapy led to immune sensitization to donor antigens, detected by the leukocyte migration inhibition test. No signs of tissue-destructive autoimmune reactions were detected in patients receiving cell therapy. Follow-up of 56 patients showed that cell therapy was associated with significant improvement of the neurological status. No serious complications of this treatment modality were observed. Presumably, cell therapy is a safe method which can be used in the treatment of craniocerebral injury aftereffects.

The results of controlled, retrospective clinical investigation of applying cell transplantation (CT) therapy in 38 severely head-injured patients are presented. The patients initially were in state of coma (Glasgow coma scale score 3--7), owing to their traumatic brain injuries. Cells prepared from fetal nervous and hematopoietic tissues were grafted subarachnoidally via lumbar puncture. The control group consisted of 38 patients and was clinically comparable with the trial one. From the results obtained it appears that CT treatment promoted both wakening consciousness of the patients and their following neurological rehabilitation. A death-rate in the trial and control group was 5% (two cases) and 45% (17 cases), respectively. According to a Glasgow scale, favorable (good+satisfactory) outcomes of a disease were noted in 33 (87%) cell-grafted and only in 15 (39%) control patients. Statistical analysis revealed that CT treatment generally improved the outcomes by 2.5-fold. No serious complications of CT therapy were noted. The results point out a possible rationality of applying CT therapy in severely head-injured patients as early as within acute period of a disease.

The paper presents the results of a controlled study of cell therapy in 30 patients with severe forms of cerebral palsy. A cell suspension from immature nervous and hemopoietic tissues was injected into the subarachnoidal space of a recipient through a spinal puncture. Immune sensitization to donor antigens (detected by suppression of lymphocyte migration) was noted in few patients. In none patients laboratory and clinical signs of tissue-destructive autoimmune reactions were observed. One year after treatment activity of the major psychomotor functions in treated patients considerably surpassed the normal. No delayed complications of cell therapy were noted. These findings suggest that cell therapy is an effective, safe, and immunologically justified method of therapy for patients with cerebral palsy.

Nucleated erythroid cells (EC) have been previously reported to possess a potent natural suppressor (NS) activity for B-cell responses. In this study, we demonstrate that murine EC are able to reduce not only lipopolysaccharide (LPS)-driven B-cell proliferation, but also proliferative and cytotoxic T-cell responses generated in a primary allogeneic mixed lymphocyte culture (MLC); and that a soluble low molecular weight factor may be involved in such EC-derived immunoregulation. In addition, the erythroid cell-derived suppressor factor (ESF) was found to be capable of effectively reducing the allergen-driven proliferation of peripheral blood mononuclear cells (PBMC) isolated from allergic patients. From the data presented herein, it appears that ESF is heat-stable (80 degrees C for 20 min) and has molecular weight (MW) lower or close to 0.5 kDa. ESF activity is resistant to both enzyme (trypsin plus chymotrypsin) proteolysis and action of the enzymes such as lipase and phospholipase C. On the other hand, ESF is effectively inactivated by neuraminidase treatment, suggesting the presence in its structure of sialic residue(s). The neuraminidase-sensitive, ESF-like activity is readily detected in the medium conditioned with normal mouse bone marrow (BM) cells. On fractionation of low MW erythroid products on a reversed-phase C16 column in a linear acetonitrile gradient (5-95%), ESF activity is detected in the first peak alone with the shortest time of its retention by the column. The results suggest that (1) by producing ESF, EC may regulate both B- and T-cell-mediated immune processes and (2) based on its physicochemical and biological characteristics, ESF can be distinguished from each of earlier characterised suppressor mediators of bone marrow origin.

In this paper we review our experimental findings concerning the capacity of bone marrow cells (BMC) to control leukemic cell growth. It has been shown that the cells isolated from normal bone marrow can provide dose dependent suppression of the proliferative activity of leukemic cells in vitro. BMC cytostatic effect is antigen non-specific and does not associate with cell death. Cytostatic BMC differ from mature macrophages, T and B lymphocytes and have the lower floating density. These cells are detected in both aggregated and non-aggregated fraction of BMC, stimulated by wheat germ agglutinin. During long-term cultivation of bone marrow the cytostatic activity was associated with the radioresistant stromal cells. Both soluble factors and cell-to-cell interactions are involved into the cytostatic process generated by BMC. Based on the obtained results, we suggest that the cytostatic activity of BMC may be increased under the influence of lymphokines, such as IL-2 and IFNgamma.

A possible mechanism for maintaining immune memory, based on idiotypic-anti-idiotypic interactions, is described. It is proposed that pendular dynamic swings in the levels of idiotypic antibodies (Ab1) and anti-idiotypic Ab2 may underlay immune memory. In the terms of the advanced concept, Ab dynamics in the maternal body might also play a significant role in education of the neonatal immune system.

It is assumed that production by differentiated cells of soluble receptors to cell growth factors may mediate a feedback mechanism controlling cell growth and differentiation in the body. Based on this assumption, it is hypothesized that with age a concentration of such soluble receptors in the body fluids gradually augments as a consequence of increasing a proportion of the differentiated cell pool. In the old body, when present in the cellular microenvironment at relatively high concentrations these receptors might markedly diminish ligand binding to the membrane-bound counterparts in a competitive manner and, thereby, significantly reduce cell regeneration activity. Under such conditions, the niches forming because of cell death could be being filled by connective fibers rather than newly generated cells.

Nucleated erythroid cells (NEC) have been previously reported to the capable of suppressing antibody-mediated primary (IgM) and secondary (IgG) immune responses to thymus-dependent antigens. In the present study we indicated that NEC, separated from the spleens of mice following phenylhydrazine treatment were able to suppress directly the proliferative response of preactivated B cells to lipopolysaccharide (LPS) in vitro. While being active in suppressing B cell blastogenesis, NEC, however, failed to reduce both cell proliferation and cytotoxic T lymphocyte (CTL) generation in an allogeneic mixed lymphocyte culture (MLC). NEC also lacked a significant effect on interleukin (IL)-2 production and utilization by concanavalin A (Con A)-activated T lymphocytes. The NEC-derived suppression of B cell proliferation was, at least in part, mediated by soluble molecules. The specific blockade of transforming growth factor (TGF)-beta synthesis with antisense oligodeoxynucleotides (OD) binding TGF-beta mRNA, as well as the neutralization of TGF-beta activity with anti-TGF-beta antibodies (Ab), resulted in a detectable diminished ability of the NEC-conditioned medium (CM) to suppress B cell blastogenesis. Taken together, the results suggest that: 1) NEC may suppress directly B cell responses, while not affecting T cell ones; 2) NEC may mediate their natural suppressor (NS) activity partially through releasing TGF-beta.

The murine bone marrow (BM) cells having a certain phenotypic similarity to null natural suppressor (NS) cells have been previously established to be able to inhibit in vitro leukemic cell growth in a genetically unrestricted manner. In this study we found that the treatment of normal (C57BL/6 x DBA)F1 BM cells with a lysosomotropic agent, L-leucine methyl ester (LME), largely abrogated their ability to reduce both P815 mastocytoma and L1210 lymphoma cell proliferation, as well as their NS activity tested for suppression of mitogen (Con A or LPS)-driven spleen cell proliferation. However, after being depleted of the cells binding wheat germ agglutinin (WGA), the BM cells maintained tumor growth-inhibitory activity, while demonstrating no significant NS activity. Moreover, in contrast to T-cell blastogenesis-inhibitory NS activity of BM cells, that was greatly reduced by the addition into the culture of either neutralizing anti-interferon (IFN)-gamma antibody (Ab) or NG-monomethyl-L-arginine, a competitive inhibitor of NO synthase, natural antitumor cytostatic activity of BM cells was not found to be dependent on the presence in medium of IFN-gamma and to be associated with NO production. When incubated at suboptimal numbers with tumor cells on conic, round, and flat well bottoms for 7 h, BM cells provided the most, middle, and least (or no) tumor growth inhibition, respectively, suggesting, thereby, a significance of cell density in cytostatic process. It was also found that the BM cells cultured for 20 h with the medium conditioned by mitogen-preactivated T or B lymphocytes were significantly more suppressive to tumor cell proliferation than the BM cells cultured in medium alone. The potentiation of BM-cell cytostatic activity by T-cell-conditioned medium (CM), but not that by B-cell-CM, was found to be partially reversed by anti-IFN-gamma Ab. Finally, a noticeable tumor growth-inhibitory activity, which could be significantly enhanced upon T-cell-CM, was shown to be also attributable to BM cells from athymic BALB/c mice. Taken together, the results suggest that (1) the tumor growth inhibitory BM cells and the NS BM cells are not identical in their cell compositions, but also differ in their mechanisms of antiproliferative action; (2) a contact cell-to-cell interaction may play a significant role in BM-cell-mediated tumor growth inhibition; (3) the activated lymphocytes, through both IFN-gamma-mediated and IFN-gamma-independent pathways, are able to operatively up-regulate the cytostatic activity of BM cells; and (4) the tumor growth-inhibitory activity exhibited by the normal unmanipulated BM cells, at least in its significant part, may not be a consequence of thymus-dependent immune processes occurring normally in the body.

Hybrid (C56BL/6 x DBA) (BDF1; H-2b/H-2d) mice bearing the P815 leukemia (H-2d) were grafted with a (CBA x C57BL/6)F1 (CBF1; H-2k/H-2b) cell suspension, comprising bone marrow cells (BMC; 25 x 10(6)/mouse) and spleen cells (SC; 55 x 10(6)/mouse) on day-4, then treated with cyclophosphamide (200 mg/kg) on day-2 and finally grafted once more with CBF1 cells (25 x 10(6) BMC + 7 x 10(6) SC) on day 0. Allogeneic cell graftings performed in this way induced durable mixed hematopoietic chimerism and significantly prolonged the survival of recipients, compared with that of leukemia-bearers grafted with syngeneic cells. The results obtained raise the possibility of using allogeneic hematopoietic tissue transplantation in combination with non-lethal cytoreductive therapy to induce a long-lasting graft-vs-leukemia effect.

Interferon-gamma (IFN-gamma) and transforming growth factor-beta (TGF-beta) are known to be a potent inducer and inhibitor for macrophage (Mo) activation process, respectively. In the present study we established that the nucleated erythroid cells (NEC) separated from the spleens of adult (CBA x C57BL/6)F1 (CBF, H-2k/H-2d) mice following phenylhydrazine treatment are potentially capable of inducing nitric oxide (NO) production in thioglycollate broth-elicited peritoneal macrophages (Mo). The stimulating effect of both NEC and their culture supernatant on NO secretion by Mo was most apparent in the presence of bacterial lipopolysaccharide (LPS) and neutralizing antibodies (Abs) to TGF-beta and was largely reversed by the addition to the culture of neutralizing Abs to IFN-gamma. Collectively these results suggest that NEC, through production of IFN-gamma and TGF-beta, may exert a regulatory influence on development and functionality of cells pertaining to monocyte (Mc)/Mo lineage.

On the basis of the data indicating the existence of two types of immuno-protection, namely macrophage-mediated and mast cell-basophil-mediated, it is argued that by reacting with potential pathogens, pre-existing IgM and IgG antibodies (both natural and induced by environmental microflora) might promote involvement of macrophages in the presentation process, favouring the generation of pathogen-specific T helper 1 (Th1), but not Th2, responses. Alternatively, the failure of these antibodies to effectively recognize pathogens might be associated with active involvement of pathogen-specific B cells in presenting Ag and, as a consequence, with the predominant development of Th2, rather than Th1, responses.

When normal murine bone marrow (BM) cells were cultured with either L1210 lymphoma cells or P815 mastocytoma cells for 24 h, considerable tumor growth suppression without substantial tumor cell lysis was found. Under the same conditions, normal spleen cells also demonstrated the antitumor cytostatic activity, but not as significant as that characteristic of BM cells, whereas both normal thymus and lymph node cells had not any suppressive effect on tumor cell proliferation. The comparable cytostatic effects occurred in both syngeneic and allogeneic BM-tumor cell combinations. The cytostatic BM-effectors were distinct from T and B lymphocytes or mature macrophages. After being separated on a discontinuous Percoll density gradient, the cells active in suppressing tumor growth were recovered predominantly in 1.075 and 1.060 density fractions. The cytostatic BM effectors, at least in their part, were resistant to x-irradiation up to 2000 rad included. Collectively these results suggest that normal BM, being deficient in cell-mediated antitumor cytolytic activity, has a significant leukemia growth inhibitory potential; and that cytostatic BM effectors are similar in their characteristics to natural suppressor cells.

When bone marrow (BM) cells, isolated from normal (C57BL/6 x DBA/2)F1 mice (H-2b/H-2d), were cultured with leukemic cells for 24 hours, a significant tumor growth suppression, without noticeable tumor cell killing, was found. The level of BM cell-mediated cytostasis of both P815 mastocytoma (H-2d) and L1210 lymphoma (H-2d) cells was dependent on BM-to-tumor cell ratio; 100% growth inhibition was obtained at a ratio of 480/1. In addition, BM cells were found to be able to synergize in suppressing P815 cell growth with lymphoid cells. The synergistic suppressive effects on tumor cell proliferation were observed in BM-spleen, BM-thymus and BM-lymphnode cell co-cultures. The analysis of cytostatic activity of the cell culture supernatants showed that the synergistic leukemia growth suppression could be mediated, at least in part, by cell-derived soluble cytostatic molecules. The data presented herein also indicated that culturing BM cells with either crude supernatant (25%) from allogeneic mixed lymphocyte culture (MLC) or recombinant human interleukin(IL)-2 (20 U/ml) for 20 hours led to a 2-fold increase in their cytostatic activity against both P815 and L1210 cells. Taken together, the results suggest that although normal BM cells are ineffective in tumor cell killing, they may play an important role in cell-mediated effector mechanisms responsible for suppressing leukemia development; and that activated T lymphocytes, through producing cytokine(s), may rapidly upregulate leukemia growth inhibitory activity of BM cells.