A thorny pathway of macrophage activating factor (GcMAF): from bench to bedside

Vitamin D3 Binding Protein (DBP) is a multifunctional glycoprotein whose main role is to transport vitamin D3 and its metabolites, but it also is the precursor of the macrophage activating factor (GcMAF). DBP is converted to GcMAF as a result of site-specific selective deglycosylation under the action of β-galactosidase and sialidase, localized on activated B and T cells, respectively. GcMAF exerts its biological activity primarily as the capability of activating macrophages by enhancing their phagocytic function and producing ROS. Activation results in elevated expression of the specific macrophageal surface receptors involved in the recognition of tumor-associated antigens, as well as in the implementation of direct anticancer activity by inducing the apoptosis or necrosis of tumor cells. Increased interest in GcMAF is associated with its potential to be used in the clinic as a new antitumor drug. Besides its anti-tumor activity, GcMAF exerts a potential against a number of viral and neurodegenerative diseases associated with increased activity of N-acetylgalactosaminidase (nagalase) in the blood serum of patients. Nagalase is an enzyme that completely (rather than selectively) deglycosylates DBP so it cannot be converted to GcMAF, leading to immunodeficiency. Circulating DBP is composed of unmodified and O-glycosylated molecules with the glycosylation degree being dependent on the allelic variants of the gene encoding DBP. The role of DBP in the resistance of organism against a number of diseases is supported by the increased risk of a variety of severe illnesses (amyotrophic lateral sclerosis, colorectal cancer etc.) in patients deficient for GcMAF due to homozygosity for defective DBP alleles. In this review, we also will examine in detail the current data i) on the structure and functions of DBP, as the main precursor of GcMAF, ii) on the main mechanisms of GcMAF anticancer effect, iii) on the tumor strategy for neutralizing GcMAF activity, iv) on the results of GcMAF clinical trials in various cancers; and will discuss the available controversies regarding the positioning of GcMAF as an effective antitumor drug

Regulation of acetylcholinesterase activity by nitric oxide in rat neuromuscular junction via N-methyl-d-aspartate receptor activation

Acetylcholinesterase (AChE) is an enzyme that hydrolyses the neurotransmitter acetylcholine, thereby limiting spillover and duration of action. This study demonstrates the existence of an endogenous mechanism for the regulation of synaptic AChE activity. At the rat extensor digitorum longus neuromuscular junction, activation of N-methyl-d-aspartate (NMDA) receptors by combined application of glutamate and glycine led to enhancement of nitric oxide (NO) production, resulting in partial AChE inhibition. Partial AChE inhibition was measured using increases in miniature endplate current amplitude. AChE inhibition by paraoxon, inactivation of NO synthase by Nω-nitro-l-arginine methyl ester, and NMDA receptor blockade by dl-2-amino-5-phosphopentanoic acid prevented the increase in miniature endplate current amplitude caused by amino acids. High-frequency (10 Hz) motor nerve stimulation in a glycine-containing bathing solution also resulted in an increase in the amplitude of miniature endplate currents recorded during the interstimulus intervals. Pretreatment with an NO synthase inhibitor and NMDA receptor blockade fully eliminated this effect. This suggests that endogenous glutamate, released into the synaptic cleft as a co-mediator of acetylcholine, is capable of triggering the NMDA receptor/NO synthase-mediated pathway that modulates synaptic AChE activity. Therefore, in addition to well-established modes of synaptic plasticity (e.g. changes in the effectiveness of neurotransmitter release and/or the sensitivity of the postsynaptic membrane), another mechanism exists based on the prompt regulation of AChE activity. NO molecules depress AChE activity in the neuromuscular junction thereby enhancing endplate current amplitude. Endogenous glutamate, released into the synaptic cleft as a co-mediator of acetylcholine, is capable of triggering the NMDA receptor-/NO synthase-mediated pathway that modulates synaptic AChE activity. In addition to well-established modes of synaptic plasticity another mechanism exists based on the prompt regulation of AChE activity. © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd

Wound healing and anti-inflammatory effects of recombinant human angiogenin

New effective wound healing agents are a priority for modern clinical pharmacology. A promising approach would be to develop medicinal products that promote angiogenesis, which is a critical step in wound healing. The aim of the study was to evaluate the wound healing effect of a medicinal product based on recombinant human angiogenin in gel form in various experimental models. Materials and methods: white outbred male rats were used as experimental ani mals. The study compared healing effects of a regenerating product containing recombinant human angiogenin (0.0025%) in gel form and a reference product in full-thickness excision, incision, and burn wound models. The healing effect of the test product in treating chronic wounds was assessed in a model of alloxan-induced diabetes mellitus. The anti-inflammatory effect of the test product containing recombinant human angiogenin was compared with that of another reference product in a model of adjuvant-induced arthritis. Results: according to the study, the test product based on recombinant human angiogenin exerts higher wound healing effect in treating excision, incision, and burn wounds than the reference product (Solcoseryl gel). Being applied, the test product intensifies tissue repair in chronic wounds in the model of alloxan-induced diabetes. The dissociation of necrotic tissues and the progression towards epithelialisation at wound edges are more rapid. The anti-inflammatory effect of the test product based on recombinant human angiogenin is comparable with that of the reference product (Diclofenac gel). Conclusions: the test product based on recombinant human angiogenin in gel form was found to have pronounced wound healing and anti-inflammatory effects comparable with those of reference products

Phosphate-modified CpG oligonucleotides induce in vitro maturation of human myeloid dendritic cells

Myeloid dendritic cells (DCs) play an important role in the immune response; therefore, the search for compounds that can effectively activate DCs is a needful goal. This study was aimed to investigate the effect of synthetic CpG oligodeoxynucleotides (CpG-ODN) on the maturation and allostimulatory activity of myeloid DCs in comparison with other PAMP and DAMP molecules. For the research, we synthesized known CpG-ODN class C (SD-101 and D-SL03) containing thiophosphate internucleotide groups, and their original phosphate-modified analogues (SD-101M and D-SL03M) with mesylphosphoramide internucleotide groups (M = μ-modification). The effects of CpG-ODN and other activators were evaluated on DCs generated from blood monocytes in the presence of GM-CSF and IFN-α (IFN-DC) or IL-4 (IL4-DC). Evaluation of the intracellular TLR-9 expression showed that both types of DCs (IFN-DC and IL4-DC) contained on average 52 and 80 % of TLR-9-positive cells, respectively. The CpG-ODNs studied enhanced the allostimulatory activity of IFN-DCs, and the effect of μ-modified CpG-ODNs was higher than that of CpG-ODNs with thiophosphate groups. The stimulating effect of CpG-ODN at a dose of 1.0 μg/ml was comparable (for D-SL03, D-SL03M, SD-101) with or exceeded (for SD-101M) the effect of LPS at a dose of 10 μg/ml. At the same time, IFN-DCs were characterized by greater sensitivity to the action of CpG-ODNs than IL4-DCs. The enhancement of DC allostimulatory activity in the presence of CpG-ODNs was associated with the induction of final DC maturation, which was confirmed by a significant decrease in the number of CD14+DC, an increase in mature CD83+DC and a trend towards an increase in CD86+DC. Interestingly, the characteristic ability of LPS to enhance the expression of the co-stimulatory molecule OX40L on DCs was revealed only for the μ-analogue SD-101M. In addition, CpG-ODNs (SD-101 and SD-101M) had a stimulatory effect on IFN-γ production comparable to the action of LPS. The data obtained indicate a stimulating effect of CpG-ODN on the maturation and allostimulatory activity of human myeloid DCs, which is more pronounced for μ-modified analogs

Evaluation of a strategy for tumor-initiating stem cell eradication in primary human glioblastoma cultures as a model

Primary cultures of human glioblastoma were obtained from the surgical material of patients K. (female, 61 years, Ds: relapse of glioblastoma) and Zh. (female, 60 years, Ds: relapse of glioblastoma). The effectiveness of a new therapeutic approach aimed at destroying the cancer cell community was evaluated on the primary cell lines of human glioblastoma culture by employing a new strategy of tumor-initiating stem cell synchronization and a domestic strategy of their eradication "3+1". The key elements of the strategy were the following indicator results: (1) evaluation of the presence of tumor-initiating stem cells in a population of cells from analyzed cultures by their ability to internalize double-stranded labeled DNA (TAMRA+ cells); (2) determination of the reference time points of the repair cycle of DNA interstrand cross-links induced by cross-linking cytostatic mitomycin C; (3) evaluation of cell cycle synchronization; (4) determination of the time (day after therapy initiation) when TAMRA+ cells were synchronously present in phase G1/S of the cell cycle, sensitive to the therapy; and (5) establishment of the TAMRA+ (tumor-initiating stem cells) eradication schedule. The cultures were treated with cross-linking cytostatic mitomycin C and a compositional DNA preparation. After the treatments, cell division slows down, and the cultures degrade. The K cell line completely degraded within 30 days of observation. The cell number of the Zh culture fell to nearly one-third of the starting value by day 15 of observation. On day 15, this indicator constituted 1/7.45 for mitomycin C and 1/10.28 for mitomycin C + DNA with reference to the control. The main target of the mitomycin C + DNA regimen was TAMRA+ tumor-initiating stem cells of the glioblastoma cell populations. The action of mitomycin C alone or in the combination with DNA demonstrated effective elimination of TAMRA+ tumor-initiating stem cells and the whole primary cultures of human glioblastomas

Expression of genes of cytokines, transcription factors and differentiation antigens in human dendritic cells activated by double-stranded DNA

One of the most important properties of extracellular double-stranded DNA related to the treatment of various diseases is its ability to activate effector cells of the immune system (anti-tumor and vaccinal immunity) through dendritic cells (DCs). The stimulatory effect of DNA on DCs is mediated by the TLR9 signaling pathway and/or through a system of cytosolic sensors and is manifested by increased expression of MHC class II antigens and costimulatory molecules and by increased synthesis of immunoregulatory cytokines. In this work, the expression of cytokines, differentiation antigens and transcription factor genes has been investigated in DCs activated by double-stranded human DNA (i) without any additional factors, (ii) using a lipophilic agent, and (iii) by blocking TLR9 with chloroquine. Evaluation of the DNA effect was carried out after the 6- and 24-hour exposure. It was found that the preparation of double-stranded DNA transfected by Lipofectamine 2000 boosts DCs at the same level as Poly(dA : dT), a synthetic equivalent of double-stranded DNA. It was discovered that combined application of DNA and chloroquine enhances expression of the IFN-α, IFN-β, IFN-γ, IL­8, МСР1, VEGF, CD25, and CD83 genes by hour 24 of incubation. It was for the first time shown that genomic “self” double-stranded DNA as a mono agent activates mRNA synthesis of cytokines IFN-α, IFN-β, IFN-γ, IL­8, IL­10, and VEGF in DCs at 6 hours of induction

Effect of macrophage-activating factor (GcMAF-RF) upon ex vivo polarization of macrophages, activation of dendritic cells and production of cytokines by human whole blood cells

This article is the second communication in a series of articles devoted to the effects of a domestic preparation of macrophage-activating factor (GcMAF-RF) and assessment of its biological properties. The aim of this work was to study the effect of the GcMAF-RF upon M0 → M1 polarization of macrophages (Mph), and activation of the professional properties of ex vivo generated antigen-presenting dendritic cells (DC), as well as on ex vivo production of pro-inflammatory (TNFα, IL-1β, IL-6, IFNγ, IL-17, IL-18) and anti-inflammatory (TGF-β, IL-4, IL-10) cytokines, growth factors (IL-2, GM-CSF, G-CSF, VEGF) and chemokines (MCP, IL-8) by the whole blood cells from healthy donors. Mph and DC were generated from the monocytes (3 to 5×106 /ml) derived from adherent fraction of peripheral blood mononuclear cells (MNC) of healthy donors. Granulocyte/macrophage colony-stimulating factor (rhGM-CSF) was used to obtain Mph, whereas DC production was induced by GM-CSF and interferon-α. To provide M1 polarizing signals, bacterial lipopolysaccharide (LPS from E. coli 0114:B4) was used in controls. In experimental series, GcMAF-RF was added 48 h before the end of culture. The stimulating effect of the obtained Mph and DC upon cell proliferation was assessed in allogeneic mixed culture of leukocytes (alloMLC) using radiometric technique, by 3 H-thymidine incorporation. The influence index (IR) of Mph or DC upon allo-SCL was calculated as the ratio of the proliferative response of MNCs in the presence of Mph, or DC to the level of spontaneous MNC proliferation. To determine the cytokine production by human whole blood cells ex vivo, peripheral blood samples from 3 donors with two replicate GcMAF-RF preparations were used, at a total of 6 points. All variants of the study were carried out with mitogen-activated and non-activated blood cells. The cytokine content was determined by the ELISA assays. The effects of GcMAF-RF were quantified as a fold increase (FI), i.e., the ratio of cytokine production in the presence of GcMAF-RF to the level of their spontaneous production. It was shown that the GcMAF-RF preparation was as effective, as lipopolysaccharide (LPS), the standard Mph and DC activator which induces polarization of differentiated M0-macrophages into M1 cells and final maturation of DCs, manifesting by a significant increase in their allo-stimulatory activity in a mixed leukocyte culture (allo-MLC). Moreover, GcMAF-RF stimulates production of numerous cytokines and chemokines (TNFα, IL-1β, IL-6, IL-18, IL-4, IL-10, GM-CSF, G-CSF, VEGF, IL-8), by blood cells (granulocytes, lymphocytes, monocytes), thus indicating direct participation of the macrophage activator GcMAF-RF in various immune processes. The domestic GcMAF-RF drug induces polarization of macrophages M0 → M1, final maturation of DCs and allostimulating activity of Mf and DCs, and is also able to effectively stimulate circulating blood cells to synthesize cytokines/chemokines with pro-inflammatory and immunoregulatory activities

Eradication of Krebs-2 primary ascites via a single-injection regimen of cyclophosphamide and double-stranded DNA

Previously, we reported on the development of a therapeutic regimen allowing eradication of primary murine Krebs-2 ascites transplants. This protocol involved multiple injections of dsDNA preparations administered during the NER and HR phases of repair of interstrand DNA cross-links induced by prior cyclophosphamide treatments. Mice treated under this protocol frequently developed secondary ascites, which indicated that some tumor-inducing cancer stem cells could survive the treatment and caused relapse. Further, we observed that animals receiving multiple dsDNA injections developed pronounced systemic inflammatory response. This prompted us to develop a more straightforward treatment regimen based on the synergistic activity of cyclophosphamide and dsDNA preparations, which would allow complete eradication of established primary Krebs-2 ascites and also be less toxic for the treated animals. This protocol relies on a precisely timed single injection of dsDNA during the NER/HR transition period of each repair cycle. Under this protocol, 8-day remission of Krebs-2 engrafted mice was achieved, which was similar to the results of the multiple-injection treatment schedule. We observed an increase in the average life span of Krebs-2- transplanted mice on a single-injection regimen, which was consistent with reduced toxicity of such treatment