[STRESS-PROTECTIVE EFFECT OF HUMAN LACTOFERRIN].

Lactoferrin - multifunctional glycoprotein of the transferrin family with a molecular mass of about 80 kDa. We studied the effect of human lactoferrin on stress-induced changes in the level of corticosterone and adrenocorticotropic hormone (ACTH) and redistribution of leukocytes in the blood of rats. The used model of stress - swimming in cold water (1-4 °C) for 2 minutes. Corticosterone and ACTH levels in the plasma were determined by enzyme immunoassay. It has been established that preventive intraperitoneal administration of lactoferrin has reduced stress-induced increase in the concentration of corticosterone in 30 minutes after the stress and has normalized stress-inducing changes in the number of neutrophils in the blood after 30 minutes and 3 hours after exposure of stress, but has not affected the level of ACTH. The results of this study suggest that lactoferrin can act as an adaptogen during experimental stress.

Effects of defensin and lactoferrin on functional activity of endothelial cells in vitro.

We studied the effects of antibacterial peptides and proteins (defensins and lactoferrins) on functional activity of endothelial cells in vitro: proliferative activity and adhesion of human endothelial ECV-304 cells to the matrix were evaluated, alpha-Defensin (NP-2) from rabbit neutrophils, total alpha-defensin (HNP 1-3) from human neutrophils, and lactoferrins from porcine neutrophils and human milk were studied. Defensins stimulated and lactoferrin in doses of 1-10 microg/ml inhibited proliferation and adhesion of endothelial cell. The stimulatory effect of defensins on proliferation and adhesion was reproduced in fibroblast culture. Lactoferrins did not modify proliferation of fibroblasts, but suppressed their adhesion. These data suggest that antibiotic proteins and peptides are prospective objects for the creation of drugs regulating angiogenesis.

[Matrix metalloproteinases: significance in remodeling of the myocardium in valvular heart disease].

AIM: To assess concentration of metalloproteinase (MMP) -9 and its inhibitor in blood serum of patients with defects of left cardiac chambers, associated with pressure or volume overload. RESULTS: Elevation of MMP-9/TIMP-1 ratio at the account of MMP-9 was characteristic for patients with volume overload while elevation of blood serum level of TIMP-1 was characteristic for patients with pressure overload. MMP-9/TIMP-1 coefficient was directly related to left ventricular myocardial mass index and negatively related to myocardial contractile capacity. In patients with aortic stenosis elevation of TIMP-1 content was associated with lowering of global left ventricular contractility. Concentration of MMP-9 in blood serum and MMP-9/TIMP-1 ratio depended on etiology of valvular heart disease. Values of the given parameters were maximal in patients with mesenchymal dysplasia and sclerodegenerative calcinosis of the aortic valve. CONCLUSION: Serum levels of MMP-9 and TIMP-1, as well as MMP-9/TIMP-1 ratio reflect type and severity of hypertrophy of the myocardium and can be looked upon as markers of myocardial remodeling.

alpha-Defensins from blood leukocytes of the monkey Papio hamadryas.

Three antimicrobial peptides named PHD1-3 (Papio hamadryas defensin) have been isolated from hamadryas baboon blood leukocytes using preparative electrophoresis and reverse-phase HPLC. The primary structures of these peptides have been determined by automated Edman degradation and mass-spectrometry. The results suggest that the peptides belong to the alpha-defensin family. Structural homology analysis reveals that among alpha-defensins from other animal species, PHD3 is the most closely related to RMAD5 (rhesus macaque alpha-defensin) (90% homology) from rhesus macaque leukocytes and also highly similar to human alpha-defensin HD5 (60% homology), which is produced by intestinal Paneth cells. The homology of PHD3 with human neutrophil alpha-defensin HNP1 (human natural peptide) was 30%. The primary structures of PHD1 and PHD2 are most similar to RED1 (rhesus enteral defensin), one of six enteral alpha-defensins of rhesus monkeys. PHD1-3 have been shown to be active against the Gram-positive bacteria Listeria monocytogenes and Staphylococcus aureus, the Gram-negative bacterium Escherichia coli, and the fungus Candida albicans, similarly to the human HNP1 defensin.

[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.

Circular minidefensins and posttranslational generation of molecular diversity.

We purified two new minidefensins (RTD-2 and RTD-3) from the bone marrow of rhesus monkeys. Both were circular octadecapeptides that contained three intramolecular disulfide bonds and were homologous to RTD-1, a circular (theta) defensin previously described by Tang et al. (Science, 286, 498-502, 1999). However, whereas the 18 residues of RTD-1 represent spliced nonapeptide fragments derived from two different demidefensin precursors, RTD-2 and -3 comprise tandem nonapeptide repeats derived from only one of the RTD-1 precursors. Thus, circular minidefensins are products of a novel posttranslational system that generates effector molecule diversity without commensurate genome expansion. A system wherein two demidefensin genes can produce three circular minidefensins might allow n such genes to produce (n/2)(n+1) peptides.

[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.

[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.

Prophenin-1, an exceptionally proline-rich antimicrobial peptide from porcine leukocytes.

We purified and characterized an unusual antimicrobial peptide, prophenin-1 (PF-1), from porcine leukocytes. The peptide had a mass of 8,683 and contained 79 residues, including 42 (53.2%) prolines and 15 (19.0%) phenylalanines. Its N-terminal 60 residues consisted of three perfect and three nearly perfect repeats of a decamer, FPPPNFPGPR. Prophenin-1 was encoded on a cathelin-containing precursor and showed substantially more activity against E. coli, a Gram-negative bacterium, than against Listeria monocytogenes, a Gram-positive organism, in vitro.