[Effects of antimicrobial peptides of neutrophils on tumor and normal cells in culture].

We performed a comparative study of effects of two structurally different cationic antimicrobial peptides of cathelicidin family, porcine protegrin 1 (PG1) and caprine bactenecin 5 (Bac5) on selected tumor and normal mammalian cells in vitro. Protegrins are amphiphilic beta-hairpin molecules having broad-spectrum antimicrobial activity due to their marked membranolytic properties. Bac5 belongs to the group of proline-rich peptides, which adopt a polyproline type II extended helix and kill microorganisms rather by a non-lytic mechanism. We have shown that while PG1 exerts distinct and fast cytotoxic effects on most of used tumor cells being slightly less toxic for nontransformed host cell, the proline-rich Bac5 is much less cytotoxic for all the cells tested. The toxic effects of PG1 were partially declined in the presence of 10% fetal calf serum. It was revealed that PG1 was able to interact with proteins of serpin family (as had been previously established for human defensins by Panyutich et al., 1995). Pre-incubation of PG1 with alpha1-antitrypsin caused the decrease of the cytotoxic activity of the peptide and, on the other hand, the antiprotease activity of alpha1-antitrypsin was reduced after interaction of the serpin with PG1 (not with Bac5). Confocal microscopy experiments allowed to monitor the internalization of fluorescent labeled (by BODIPY FL) peptides into target cells and their intracellular distribution. Bac5-BODIPY (at 5 microM) was rapidly taken into the cells. PG1-BODIPY at non-toxic concentrations was also able to enter the cells without significant damage to them. The comparative study of the kinetics of the peptides uptake into the target cells and the influence of low temperature, energy-depletion and endocytosis inhibitors on the process of the internalization of the peptides into the cells was carried out using flow cytometry.

[Cardial fibrosis and the functional activity of leukocytes in patients with essential arterial hypertension].

The study revealed an increase in the serum levels of TGF-beta1 and the N-terminal peptide procollagen type III in patients with essential arterial hypertension (EAH), as well as an association between this increase and the duration of the disease, mean day arterial pressure profile, and left ventricular hypertrophy. An increased leukocyte functional activity is associated with disturbances in left ventricular diastolic function and an increase in TGF-beta1 serum concentration in EAH. The authors conclude that leukocytes participate in the development of myocardial hypertrophy and cardial fibrosis through the secretion of pro-inflammatory cytokines and peptide growth factors within the process of their activation.

[Cationic antimicrobial peptides as molecular immunity factors: multi-functionality].

Cationic antimicrobial peptides (AMP) of mammals (defensins, cathelicidins, protegrins and many others) are regarded as important components of congenital immunity. AMP are multifunctional molecules, capable of killing microorganisms directly by acting as endogenic, natural antibiotics ("immediate immunity"); in addition, they may take part in congenital and adaptive immune reactions (immunoregulation) and function as signal molecules, involved into tissue reparation, inflammation (including sepsis), blood coagulation and other important processes in the body. The molecular mechanisms of the direct antimicrobial action of AMP are considered. In addition to antimicrobial and immunoregulating action, AMP have influence on immunoneuroendocrine interactions, taking part in the pathogenesis of stress reactions (corticostatic action), as well as play the role of regulatory peptides of adaptogenic action. The many-sided character of the action of AMP opens prospects to the creation of new medicinal remedies on their basis. Such requirements are met by the Russian preparation "Superlymph" (a complex of natural cytokines), containing protegrin-like AMP.

[Immunological parameters and mycobacterial biological properties in infiltrative pulmonary tuberculosis].

Thirty-one patients with infiltrative pulmonary tuberculosis were clinically and immunologically examined. A relationship was found between the definite immunological parameters and the biological properties of mycobacteria. The higher viability of mycobacteria and the increase in the drug resistance have been shown to be associated with the decreased activity of lymphocytes and the suppressed production of interleukin-2, which suggests a decrease in the activity of type 1 T helper cells and a significant increase in the synthesis of tuberculosis antibodies with the lower serum concentrations of circulating immune complexes. This is an informative indicator of a severe specific process, as previously established. Moreover, the authors show certain differences in the changes of immunological parameters in patients with infiltrative pulmonary tuberculosis with varying mycobacterial properties. Thus, the results of the performed study make investigators pay a particular attention to the immunopathogenetic value of the biological properties of Mycobacterium tuberculosis.

[Parameters of acquired immunity and cation proteins of neutrophilic granulocytes in pulmonary tuberculosis]. / Pokazateli priobretennogo immuniteta i kationnye belki neitrofil'nykh granulotsitov pri tuberkuleze legkikh.

Clinical and immunological studies of 61 patients with pulmonary tuberculosis have indicated that the status of acquired and congenital (natural) immunity assessed by the intra- and extracellular levels of cation proteins of neutrophilic granulocytes is different in different clinical forms of pulmonary tuberculosis. The found correlations suggest that there is a relationship between the factors of acquired and congenital immunity and that cytokines are involved in the regulation of specific inflammation. More active degranulation of azurophilic granules of neutrophils occurs due to myeloperoxidase. Unlike other forms, fibrocavernous pulmonary tuberculosis shows a negative correlation between intra- and extracellular content of cation proteins. The findings make it possible to use the parameters of congenital immunity for more detailed characterization of an immune response in tuberculosis, which may be essential in developing new pathogenetic therapy regimens.

[Achievements and problems in studies of antibiotic peptides of an organic origin]. / Dostizheniia i problemy v izuchenii antibioticheskikh peptidov zhivotnogo proiskhozhdeniia.

The paper contains the original data of the authors and literature survey in the field of studies of the structure and functions of antibiotic peptides. Physical-and-chemical as well as structural properties of a new subfamily of defensins, i.e. minidefensins (theta-defensins), are described in detail. Mechanisms of the antibiotic action of defensins and bactenecins as well as their role in regulating the body immune reactions are discussed.

[Myeloperoxidase in the human placenta at preterm labor]. / Mieloperoksidaza v platsente cheloveka pri prezhdevremennykh rodakh.

In the present study the level of myeloperoxidase in the human placenta at premature was investigated. Mycloperoxidase content did not depend on its localization in placenta and decreased at premature labour. It is suggested that the decrease in the myeloperoxidase content in placenta results in the weakening of antimicrobial barrier in the system mother-placenta-fetus and plays an important role in pathogenesis of premature delivery at later term.

[Cytotoxic and mitogenic effect of antimicrobial peptides from neutrophils on cultured cells]. / Tsitotoksicheskoe i mitogennoe vliianie antimikrobnykh peptidov neitrofilov na kul'tiviruemye kletki.

Cytotoxic and mitogenic activities of human and rabbit defensines (HNP and NP-2, resp.) and pig antimicrobial peptides from leukocytes (PR-39, prophenin PF-2 and protegrin PG-2) were studied. The above peptides were added to serum-free cell culture medium of the target cell lines K562, L929 and Hep22a. Cytotoxicity was estimated within 1, 3, 6, 24 and 48 h of cell incubation with the tested peptides in concentrations 1, 10, 25 or 100 micrograms/ml. All the examined peptides exhibited a distinct time- and concentration-dependent cytotoxicity. Moreover, by contrast to pig peptides, defensines could induce proliferation in cell subpopulations from cell lines L929 amd Hep22a, or L929 (defensines HNP and NP-2, resp.), keeping resistance to their cytotoxic action.

[Putative molecular mechanism of defensin interaction with the membrane of the sensory neuron]. / Vozmozhnyi molekuliarnyi mekhanizm vzaimodeistviia defensina s membranoi sensornogo neirona]

NP-1 defensin decreased effective charge transfer in the activation gating system of TTX-resistant (slow) sodium channels in a dose-dependent manner. The dissociation constant and Hill coefficient values were KD = 2 pM and X--0.9. Geometry of the NP-1 defensin molecule was built using its primary structure with three S-S briges and fully optimised in the framework of molecular mechanics method. The data obtained explain experimental results of stechiometry 1:1 due to ligand-receptor interaction by the only outward directed carboxyl group of Glu 14 which might form a hydrogen bond with a single binding site of non-identified defensin membrane receptor.

[An assessment of the immune status of the mucosal membranes in chronic rhinosinusitis]. / Otsenka immunnogo statusa slizistykh obolochek pri khronicheskom rinosinusite.

The authors studied immune status of upper respiratory tracts mucosa in patients with different forms of chronic rhinosinusitis (purulent, polypous, vasomotor) in comparison to control subjects. An original complex of laboratory diagnostic techniques is proposed which can assess functional condition of the defense barriers of the upper respiratory tract mucosa in chronic inflammation, estimate impairment of specific and nonspecific resistance. This facilitates choice of optimal scheme of pathogenetic therapy of chronic inflammation in the upper respiratory tracts.

[Complex-formation between myeloperoxidase and fibronectin and its modulation by fibronectin ligands]. / Kompleksoobrazovanie mieloperoksidazy i fibronektina i ego moduliatsiia ligandami fibronektina.

Human blood plasma fibronectin immobilised on agarose in physiological interacts with soluble myeloperoxidase (Kd = 2.43 mM). Interaction of myeloperoxidase with fibronectin adsorbed on immobilised gelatin a, natural fibronectin ligand, resulted in formation more stable complex (Kd = 0.94 mM). The presence of thermoaggregated (but not native) IgG in the liquid phase increased a stability of the complex (0.06 mM). It is suggested that myeloperoxidase could represent a component of complex super molecular structure, real immune complex.

[Thermodynamic parameters of complex formation of blood plasma fibronectin and myeloperoxidase]. / Termodinmicheskie parametry kompleksoobrazovaniia fibronektina plazmy krovi i mieloperoksidazy.

Previous studies have demonstrated that fibronectin immobilized on BrCN-activated agarose forms a complex with soluble myeloperoxidase. The affinity of such interaction increases after preliminary absorption of fibronectin on a column with immobilized gelatin, one of its natural ligands. The thermodynamic characteristics of the myeloperoxidase interaction with fibronectin-gelatin-agarose have been established. The role of fibronectin-myeloperoxidase interaction in the inflammation focus is discussed in terms of the mode of the phagocyte loading with the enzyme and as a way of protecting intrinsic body tissues from injury by oxidants generated by extracellular myeloperoxidase.

[The action of defensins on the corticosterone level of the blood and on the immune response in stress]. / Vliianie defensinov na uroven' kortikosterona v krovi i immunnyi otvet pri stresse.

The influence of defensins on the level of corticosterone in the blood and immune response in stress was studied. Defensins were shown to have corticostatic activity in vivo in the models of stress- and ACTG-induced elevation of corticosterone. Also defensins abolished the immunosuppressive action of combining stress in animals. These results suggest that defensins may be endogenic peptides with stress-protective properties.

[Effect of defensin on platelet functional activity]. / Vliianie defensina na funktsional'nuiu aktivnost' trombotsitov.

The effects of human neutrophil peptide defensin were studied on human platelet function. Defensin (0.1-40 micrograms/mL) did not promote platelet aggregation. Defensin decreased platelet aggregation responses to ADF, collagen or thrombin. Defensin significantly lessened ATP level, released during platelet aggregation, and malondialdehyde production, induced by thrombin and collagen. These data reveal that defensins involve in cell-cell interaction between platelets and neutrophils counteracting agonist-induced platelet activation.