[Cytopenias and their correction during antiviral therapy of chronic hepatitis C in patients with genotype 1]

Inflammation Regulation by Bacterial Molecular Patterns

Stimulation of innate immunity by bacterial molecular patterns can induce an enhanced cellular immune response to pathogens that are associated with innate immune memory shaped by epigenetic changes. Immunological memory can be expressed in the acceleration/intensification of inflammation, as well as in the exact opposite-to maintain tolerance and non-response to a repeated stimulus. Tolerance is one of the central concepts of immunity and is ensured by the consistency of all parts of the immune response. The severe consequences of inflammation force researchers to study in detail all stages of the downstream pathways that are activated after exposure to a stimulus, while the formation of non-response to a pro-inflammatory stimulus has not yet received a detailed description. Elucidation of the mechanism of tolerance is an urgent task for the prevention and treatment of inflammatory diseases. The aim of this investigation was to study the dynamic changes in the gene expression of A20 and ATF3, the inflammation suppressors, against the background of the expression of the genes of the innate immunity receptors TLR4 and NOD2 and the pro-inflammatory cytokine TNF-α under the influence of TLR4 and NOD2 agonists, lipopolysaccharide (LPS) and glucosaminylmuramyl dipeptide (GMDP). The mechanism of inflammation regulation by bioregulators of bacterial origin-LPS and GMDP-was evaluated in vitro in human peripheral blood mononuclear cells and in vivo after i.p. administration of LPS and GMDP to mice. Gene expression was assessed by RT-PCR. Innate immune receptors and the pro-inflammatory cytokine TNF-α were found to develop early in response to LPS and GMDP, both in vitro and in vivo. Genes of cytosolic proteins controlling inflammation (A20 and ATF3) were expressed later. Prior exposure of the innate immune system to LPS and muramyl peptides may modulate host defense against acute inflammation. As a result of the study, new data were obtained on dynamic changes in deubiquitinase A20 and the transcription factor ATF3, which are involved in the limitation and suppression of inflammatory reactions caused by fragments of bacterial cell walls-LPS and GMDP. Thus, bioregulators of bacterial origin LPS and GMDP, along with pro-inflammatory factors, activate the expression of genes that suppress inflammation, which should be considered when analyzing data from studies of the pro-inflammatory properties of LPS and GMDP and when developing drugs based on them.

Innate Immunity Mechanisms in Marine Multicellular Organisms

The innate immune system provides an adequate response to stress factors and pathogens through pattern recognition receptors (PRRs), located on the surface of cell membranes and in the cytoplasm. Generally, the structures of PRRs are formed by several domains that are evolutionarily conserved, with a fairly high degree of homology in representatives of different species. The orthologs of TLRs, NLRs, RLRs and CLRs are widely represented, not only in marine chordates, but also in invertebrates. Study of the interactions of the most ancient marine multicellular organisms with microorganisms gives us an idea of the evolution of molecular mechanisms of protection against pathogens and reveals new functions of already known proteins in ensuring the body’s homeostasis. The review discusses innate immunity mechanisms of protection of marine invertebrate organisms against infections, using the examples of ancient multicellular hydroids, tunicates, echinoderms, and marine worms in the context of searching for analogies with vertebrate innate immunity. Due to the fact that mucous membranes first arose in marine invertebrates that have existed for several hundred million years, study of their innate immune system is both of fundamental importance in terms of understanding molecular mechanisms of host defense, and of practical application, including the search of new antimicrobial agents for subsequent use in medicine, veterinary and biotechnology.

Regulation of Immune Homeostasis via Muramyl Peptides-Low Molecular Weight Bioregulators of Bacterial Origin

Metabolites and fragments of bacterial cells play an important role in the formation of immune homeostasis. Formed in the course of evolution, symbiotic relationships between microorganisms and a macroorganism are manifested, in particular, in the regulation of numerous physiological functions of the human body by the innate immunity receptors. Low molecular weight bioregulators of bacterial origin have recently attracted more and more attention as drugs in the prevention and composition of complex therapy for a wide range of diseases of bacterial and viral etiology. Signaling networks show cascades of causal relationships of deterministic phenomena that support the homeostasis of multicellular organisms at different levels. To create networks, data from numerous biomedical and clinical research databases were used to prepare expert systems for use in pharmacological and biomedical research with an emphasis on muramyl dipeptides. Muramyl peptides are the fragments of the cell wall of Gram-positive and Gram-negative bacteria. Binding of muramyl peptides with intracellular NOD2 receptors is crucial for an immune response on pathogens. Depending on the microenvironment and duration of action, muramyl peptides possess positive or negative regulation of inflammation. Other factors, such as genetic, pollutions, method of application and stress also contribute and should be taken into account. A system biology approach should be used in order to systemize all experimental data for rigorous analysis, with the aim of understanding intrinsic pathways of homeostasis, in order to define precise medicine therapy and drug design.

Strategies for Using Muramyl Peptides - Modulators of Innate Immunity of Bacterial Origin - in Medicine

The spread of infectious diseases is rampant. The emergence of new infections, the irrational use of antibiotics in medicine and their widespread use in agriculture contribute to the emergence of microorganisms that are resistant to antimicrobial drugs. By 2050, mortality from antibiotic-resistant strains of bacteria is projected to increase up to 10 million people per year, which will exceed mortality from cancer. Mutations in bacteria and viruses are occurring faster than new drugs and vaccines are being introduced to the market. In search of effective protection against infections, new strategies and approaches are being developed, one of which is the use of innate immunity activators in combination with etiotropic chemotherapy drugs. Muramyl peptides, which are part of peptidoglycan of cell walls of all known bacteria, regularly formed in the body during the breakdown of microflora and considered to be natural regulators of immunity. Their interaction with intracellular receptors launches a sequence of processes that ultimately leads to the increased expression of genes of MHC molecules, pro-inflammatory mediators, cytokines and their soluble and membrane-associated receptors. As a result, all subpopulations of immunocompetent cells are activated: macrophages and dendritic cells, neutrophils, T-, B- lymphocytes and natural killer cells for an adequate response to foreign or transformed antigens, manifested both in the regulation of the inflammatory response and in providing immunological tolerance. Muramyl peptides take part in the process of hematopoiesis, stimulating production of colony-stimulating factors, which is the basis for their use in the treatment of oncological diseases. In this review we highlight clinical trials of drugs based on muramyl peptides, as well as clinical efficacy of drugs mifamurtide, lycopid, liasten and polimuramil. Such a multifactorial effect of muramyl peptides and a well-known mechanism of activity make them promising drugs in the treatment and preventing of infectious, allergic and oncological diseases, and in the composition of vaccines.

Advisable including glucosaminylmuramyldipeptide in Helicobacter pylori therapy: experience of ten-year investigation

Helicobacter pylori infection is a common bacterial infection in humans and is associated with peptic ulcer disease and chronic gastritis. The presence of natural resistance to some antibiotics in bacteria, as well as the appearance of primary and secondary resistance to antibacterial agents, complicates treatment and determines the search for new methods of therapy. The aim of this study was to evaluate the efficacy and safety of 10-year complex treatment of patients with duodenal ulcer associated with H.pylori , 136 patients (96 men, 40 women; mean age 45.8 14.8 years; 18-65 years). H.pylori was determined morphologically and by rapid urease test one day before the start of therapy, after 1, 6, 12 months, 2 years, 5 and 10 years. Patients of the first group received basic therapy: omeprazole 0.02 g 2 times a day, clarithromycin 0.5 g 2 times a day, amoxicillin 1 g 2 times a day, for 10 days (OCA group 1; n = 98). Patients of the second group, in addition to the basic therapy, took 1 mg per day drug Liсopid (group 2 OСAL; n = 38). At the 1st stage of the clinical study, 130 patients completed eradication therapy. Tracking completeness was 96 %. The frequency of H.pylori eradication after per protocol treatment: OCA - 83 % (95 % CI: 75 %-91 %), OCAL - 97 % (95 % confidence interval (CI): 92 %-100 %). The incidence of adverse reactions after treatment (per protocol): OCA - 26 % (95 % CI: 17-35 %; nausea; n = 24), discontinued treatment - 5 % (95 % CI: 0.8 %-10 %; diarrhea; n = 5); OCAL - 3 % (95 % CI: 0.01 %-8 %; nausea; n = 1), all were treated. Taking the drug Liсopid 1 mg (glucosaminyl muramyl dipeptide, JSC Peptek, Russia) as part of complex therapy contributed to the elimination of H.pylori and the absence of relapses for 2 years. Observation of patients in the next 5 and 10 years also showed the advantage of including the immunomodulator in therapy: a significant 15 % decrease in H.pylori reinfection (P 0.05), a 23 % decrease in the frequency of gastrointestinal adverse reactions (P0.01), compared with a 10-day standard triple regimen without immunomodulatory therapy with glucosaminylmuramyl dipeptide. When using several antibiotics in H.pylori eradication therapy, not only pathogenic, but also commensal microorganisms are destroyed, the waste products of which are vital and maintain immune homeostasis, including through the NOD2 receptors of innate immunity. The effectiveness of the complex therapy of H.pylori infection can be explained by the fact that the drug Liсopid compensates for the signal for innate immunity receptors that is missing due to the absence of commensals, providing an adequate immune response and preventing chronicity and recurrence of infection.