Neutrophil extracellular traps: mechanisms of formation and role in health and disease.

Recent insights into the specific type of cell death characteristic of neutrophils, called NETosis, are summarized. NETosis is a process of generation of Neutrophil Extracellular Traps (NETs), whose main components are DNA, granular antimicrobial peptides, and nuclear and cytoplasmic proteins. The structure of NETs determines their bactericidal, fungicidal, antiprotozoal, and antiviral properties. Therefore, NETs production by neutrophils is an essential immune response to infection. In addition to the antimicrobial function, NETosis is involved in many inflammatory and autoimmune disorders and participates in the regulation of noninfectious processes. The molecular mechanisms of NET formation, bactericidal effect, and involvement in some noninfectious, autoimmune, and inflammatory processes are discussed in detail in this review.

[Induction and protective properties of antibodies against muramyl peptides of gram-negative bacteria].

AIM: Characterize the role of humoral immune response in mechanisms of action of muramyl dipeptide immune stimulators. MATERIALS AND METHODS: Mice were immunized by a complex of muramyl peptides (CMP) obtained from Salmonella typhi peptidoglycan and consisting of 3 components: 1) N-acetyl-D-glucoasminyl-(beta1- > 4)-N-acetyl-D-muramoyl-L-alanyl-D-isoglutaminyl-meso-diaminopimelic acid (GMtri); 2) N-acetyl-D-glucosaminyl-(beta1- > 4)-N-acetyl-D-muramoyl-L-alanyl-D-isoglutaminyl-meso-diaminopimeloyl-D-alanine (GMtetra) and 3) GMtetra dimer (diGMtetra), in which monomeric residues of GMtetra are linked by an amid bond between carboxyl group of terminal D-alanine of one of GMtetra residues and omega-amino group of meso-diaminopimelic acid of the other GMtetra residue. RESULTS: Immunization resulted in a multifold increase of IgM, IgG1 and IgG2a titers against CMP. Antibodies were directed against the whole molecule of diGMtetra and did not recognize its fragments. Sera of mice immunized with CMP protected the mice from lethal infection with Gram-negative (S. typhimurium) but not Gram-positive (Staphylococcus aureus) microorganisms. CONCLUSION: Induction of protective antibodies may present a novel mechanism of action of muramyl dipeptide immune stimulators.

[Prediction of remote results after surgical management of patients presenting with atherosclerosis obliterans of the lower-limb arteries].

Forecasting the development of implants' narrowing appears to be one of the most important problems encountered in vascular surgery today. The present study was therefore undertaken to work out a comprehensive diagnostic methodology making it possible to reliably predict the development of stenosis of vascular anastomoses during the postoperative period in patients presenting with atherosclerosis obliterans. The work was based upon the findings obtained by examining a total of seventy-nine patients diagnosed with atherosclerosis obliterans of the lower-limbs arteries, also including assessment of a large number of haemodynamic and immunological parameters both before and after reconstructive vascular interventions. The study showed substantial dynamics of a series of immunological and haemodynamic indices on the background of the operation and during the postoperative period. Based on the mathematical processing of the obtained data, the authors managed to reveal the factors playing a leading role in the development of stenosis, having also worked out a prognostic algorithm making it possible with high reliability to predict the development of stenosis of arterial anastomoses.

[Changes in functional activity of macrophages caused by bacterial muramylpeptides].

Muramylpeptides from bacteria cell wall are strong stimulators of immune system and phagocytic cells are main effectors. Dimer containing glucoseaminylmuramylpentapeptide (di-GMPP) was obtained from cell wall of Salmonella typhi bacteria. Di-GMPP decrease the phagocytic activity of macrophages obtained from peripheral blood of healthy donors and increase intracellular killing. Also di-GMPP resulted in decrease of expression of macrophages' receptors which play role in phagocytosis (CD16, CD64, CD11b) and detection of bacterial molecular patterns (TLR2, TLR4, CD206), as well as in increase of expression of antigen-presenting (HLA-DR) and costimulatory molecules (CD86, CD40) which involved in formation of immunological synapse and presentation of antigens to T- and B-lymphocytes.

[Significance of the functional activity of toll-like receptors and other receptors of the innate immune system of the kidney physiology].

The kidney needs to defend against microbial pathogens in order to maintain normal structure and function. This is achieved through innate and adaptive components of the immune system. For a long time, immunologists were concentrating on the adaptive immune system, which, as a result, was studied in detail; at the same time, the significance of the innate immune system was underestimated. This gap was partly filled in the recently, when the key role of the innate immune system in fighting microorganisms and in activating and regulating the adaptive immune system was convincingly established. In the first part of the present article, the sense apparatus of the innate immune system (the so-called pattern-recognition receptors) will be reviewed; particular attention will be paid to the toll-like receptors (TLRs), which bear the main burden of microorganism recognition. Signalling pathways that are activated by TLRs and result in the activation of effector mechanisms will also be reviewed. In the second part of the review, we will analyse available data on how these mechanisms of the innate immune system secure defence and normal functioning of the kidney.

[Assessment of bactericidal and growth-inhibiting activity of blood serum using flow cytometry and photometry].

Method of measurement of biological fluids bactericidal activity against Staphylococcus aureus using laser flow cytometry has been developed and proposed for clinical use. Overall bactericidal activity of sera of healthy donors has been assessed by this method. Strong positive correlation between bactericidal activity measured by flow cytometry and ability of the sera of healthy donors to inhibit bacterial growth assessed by photometric method was determined. High degree of positive correlation between results of cytometry and classical microbiological method of measurement of mentioned parameters has been shown.

[Evaluation of serum bactericidal activity by laser flow cytofluorometry].

A method for evaluation of serum bactericidal activity against S. aureus by laser flow cytofluorometry has been developed and proposed for clinical application. This method was used to study the overall bactericidal activity of donors' sera and to estimate the contribution of complement to the process of bacteriolysis.

Immunomodulatory properties of Cumaside.

The medical lead, so-called Cumaside, was created on the basis of triterpene oligoglycosides from the Far-Eastern edible sea cucumber (holothurian) Cucumaria japonica and its immunomodulatory properties were studied. The haemolytic activity of Cumaside was significantly reduced in comparison with original glycosides due to the glycoside-cholesterol complex formation. The influence of Cumaside on mouse macrophages in low doses was accompanied by more then two-fold stimulation of lysosomal activity. This preparation was found to increase significantly the animal resistance against bacterial infections elicited by various pathogens. It stimulated phagocytosis, ROS formation, IL6 and TNF-alpha production in lymphocytes, increased the number of antibody producing cells and amplified the expression of several cell surface molecules (CD3, CD4, CD8) preliminary cultured with hydrocortisone. At the same time the preparation did not affect the delayed-type hypersensitivity, proliferative activity of lymphocytes, cytotoxic activity of NK-cells and cytokine IFNgamma and IL12p70 release. The mechanism of Cumaside action is discussed.

[Multiple cerebral abscess caused by Nocardia brasilientis].

Streptococcus aureus, streptococci, and enterobacteria were major causative agents of abscesses of the brain. At present, associated infection is responsible for 60% of cerebral abscesses. When systemic and specific immunities are diminished, a risk for cerebral abscesses caused by fungi increases. Among them, there are the most common fungi Candida species or Aspergillus species. The paper gives an example of successful complex treatment of multiple cerebral abscesses caused by an association of Nocardia brasiliensis and Staphylococcus epidermidis. The specific feature of the observation was the correct diagnosis before intraoperative verification of cerebral abscesses. The disease developed in the presence of diminished systemic immunity and in the absence of specific immunity to Nocardia. Immunodeficiency could be caused by prior herpetic infection, Epstein-Barr disease, a wasp bite. The pathogen that was able to cause microstrokes played an indubitable role in the pathogenesis of the disease, which predisposed to the development of cerebral abscesses in patients with immunodeficiency. Impaired blood circulation in the occipital region could be also induced by wasp venom.

[Effects of immunomodulating therapy on immune status and the disease course in patients with relapsing herpetic stomatitis]. / Vliianie immunomoduliruiushchei terapii na immunnyi status i techenie zabolevaniia u bol'nykh s retsidiviruiushchim gerpeticheskim stomatitom.

Clinical and immunological efficiency of leukinferone in combination with polyoxidonium (immunomodulator) was studied in patients with relapsing herpetic stomatitis (RHS). The levels of alpha- and gamma-IFN were decreased, levels of IgM, IgG, and IgE were increased, active oxygen forms were actively produced, and the count of CD8(+)-cells was increased in patients with RHS. Treatment with polyoxidonium and leukinferone led to an increase of the blood levels of alpha- and gamma-IFN, decrease of IgM, IgG, and IgE levels, normalization of phagocytosis, and decrease of CD8(+)-cell count. The treatment had a pronounced clinical effect in patients with RHS of any severity, which indicates the efficiency of these drugs in combined therapy of patients with RHS.

[Dendritic cells and their role in inflammation in the central nervous system]. / Dendritnye kletki i ikh rol' pri vospalenii v tsentral'noi nervnoi sisteme.

Dendritic cells play a key role in initiation and regulation of adaptive immunity against pathogens and tumors, as well as in autoimmune disease. In this article we review recent data regarding distribution of dendritic cells in the central nervous system, their role in responses and possible role in pathogenesis of multiple sclerosis. We also consider possibilities to use dendritic cells as immunotherapeutic targets in multiple sclerosis.

[Screening of natural immunosuppressors by their ability to modify steroid synthesis in hepatocytes]. / Otbor prirodnykh immunosupressorov po sposobnosti k modifikatsii sinteza sterolov kletkami gepatotsitov.

In the programme for screening sterol synthesis inhibitors with the use of actinomycetes and fungi 702 strains were tested. The effect of alcohol extracts of the mycelium of fungi and actinomycetes at a dilution of 1/10(3) on sterol synthesis by the Hep G2 hepatome cells was determined by incorporation of 3H acetate into sterols and proteins. Lovastatin (200 pg/ml) was used as the control: the sterol synthesis was decreased by 49 +/- 4% without inhibiting the protein synthesis. A number of the cultures produced compounds inhibiting under the experimental conditions the synthesis of sterols by 70 to 80% with simultaneous inhibition of the protein synthesis at least by 60 to 70%. Three compounds from that group produced by streptomycetes were subjected to a more detailed investigation. The compounds were demonstrated to be active antifungal antibiotics (MIC 0.1-1 mcg/ml). In a dose of 0.1-1 mcg/ml they showed high immunosuppressive activity in models of lymphocyte transformation in mice, whereas cyclosporin was active in a dose of 1 mcg/ml. Therefore, the model for screening hypolipidemic compounds could be considered useful for screening promising natural immunosuppressors.

[The use of immunomodulator likopid in the combined treatment pulmonary tuberculosis]. / Primenenie immunomoduliatora likopida v kompleksnom lechenii tuberkuleza legkikh.

Licopid is a synthetic analogue of a cell wall component of all bacteria. The monocytic macrophageal system is the main target of licopid's action. Addition of the immunomodulator to combined therapy for patients with pulmonary tuberculosis in order to enhance phagocytic activity exerted a marked clinical effect appeared as ceased bacterial isolation in 80% of the patients, a fall in the amount of purulent sputum, no symptoms of intoxication following 2-3 weeks, accelerated resolution of infiltrative changes. The positive clinical effect coincided with the immunological one manifested as increases in the absolute counts of CD3+CD4+ and CD3+CD8+ cells, in the absorptive and bactericidal functions of phagocytes. Such effects were not observed in patients receiving routine treatment. Licopid is recommended for supplementation to the combined treatment regimen for pulmonary tuberculosis.

[Flow laser cytometry for evaluation of the human immune system]. / Protochnaia lazernaia tsitometriia v otsenke immunnoi sistemy cheloveka.

Some flow laser cytometry (FLC) techniques intended for studies of the immune system cells are reviewed. A widespread analytical method is the phenotyping of lymphocytes by the markers they express. The use of FLC permits the evaluation of practically all functional parameters of immunocompetent cells. Thus, to analyze their ingestive and microbicidal activity fluorochrome-labeled microorganisms are used. The apploication of indicator dyes makes it possible to evaluate calcium mobilization and formation of active forms of oxygen. FLC is used for the identification of cytokines inside the cell and in the medium. The authors propose tests for the analysis of the proliferative activity of lymphocytes, the cytotoxicity of natural killers, the evaluation of apoptosis and protein processing with monocytes/macrophages.

[Clinico-immunological effectiveness of likopid in conservative treatment of patients with chronic tonsillitis and chronic sinusitis]. / Kliniko-immunologicheskaia éffektivnost' likopida pri konservativnom lechenii bol'nykh khronicheskim tonszillitom i khronicheskim sinusitom.

30 patients with chronic tonsillitis (CT) and 20 patients with chronic sinusitis (CS) received likopid (4 mg/day for 10 days). CT patients were additionally treated with tonsil lacunar lavage with dioxidine solution. Likopid was found effective in CT patients (good response--31%, partial response--59%). 9% did not respond to likopid. CS patients benefited less (good response--10%, partial response--50%). 40% were non-responders. In CT patients likopid demonstrated also an immunomodulating effect. Positive changes were observed in the counts of B-lymphocytes, T-lymphocytes, T-helpers, natural killers, level of serum IgG, titers of specific antibodies, functional activity of neutrophils. In CS this effect was less pronounced.

[Predicting purulent complications in surgery by determining antibody affinity]. / Prognozirovanie gnoinykh oslozhnenii v khirurgii s pomoshch'iu opredeleniia affinnosti antitel.

Blood serum of 153 operated patients was studied, 133 of them had uncomplicated postoperative period, 20 patients had postoperative infectious complications. Control group consisted of 23 healthy donors. Coefficient of antibodies affinity was deduced mathematically. If this coefficient didn't exceed 15%, probability of complications development was 90%; if this coefficient ranged from 15 to 30%, probability of complications was 50%; if coefficient exceeded 30%, complications in postoperative period were the least probable. This method can be used for humoral immunity evaluation in surgical patients, bearing in mind its prognostic and diagnostic significance.

[The effect of the immunomodulator likopid on cytokine synthesis and on the activation molecules of the peripheral blood lymphocytes in patients with lichen ruber planus]. / Vliianie immunomoduliatora likopida na sintez tsitokinov i aktivatsionnye molekuly limfotsitov perifericheskoi krovi bol'nykh s krasnym ploskim lishaem.

Clinical and immunological efficacy of immunomodulator likopide has been studied in patients with lichen planus. The levels of peripheral blood lymphocytes and CD3+ lymphocytes, containing antiinflammatory cytokine gamma-interferon in the cytoplasm, are increased in these patients. Likopide therapy led to a notable decrease in the content of lymphocytes and CD3+ lymphocytes containing this cytokine. The count of lymphocytes containing inflammatory cytokine interleukin-4 (IL-4) in the cytoplasm is the same in patients with lichen planus and donors. Likopide stimulated the production of this interleukin by peripheral blood mononuclears. Expression of early activation antigen CD69 on CD3+ and CD3+CD8+ lymphocytes can be a sign of improvement of these cells' function. The drug had a pronounced clinical effect in virtually all forms of lichen planus, which may be due to suppression of the activity of TH1 cells producing inflammatory cytokines and an increase in the functional activity of TH2 cells producing antiinflammatory cytokines and to normalization of the functional activity of T lymphocytes, manifesting by a higher expression of early activation antigen CD69 involved in the production of IL-2.

[The use of biological preparations for correction of microbial status in pregnant women]. / Primenenie bioterapevticheskikh preparatov dlia korrektsii mikrobnogo statusa u beremennykh zhenshchin.

15 pregnant women with pregnancy lasting 28-32 weeks, whose medico-laboratory data (the positive result of the amino test, high pH value and the detection of "key" cells) suggested the presence of bacterial vaginosis, were placed under observation. The bacteriological study of vaginal microflora in all these women revealed pronounced disturbances simultaneously with the development of intestinal dysbacteriosis. The local application of the bacterial preparation "Zhlemik" containing freeze-dried live lactic acid bacteria of vaginal origin and the oral administration of lactic acid bifidumbacterin containing live bifidobacteria of intestinal origin permitted the successful restoration of vaginal and intestinal microbiocenosis. The capacity of biotherapeutic preparations for inducing non-specific immunostimulation led to a significant rise in the levels of IgA, IgM and IgG in vaginal secretions.