[Effect of ribosomal proteins of respiratory bacteria on adhesive properties of buccal epitheliocytes].

AIM: Study the effect of ribosomal proteins of respiratory bacteria composing the basis of the immune-modulating preparation ribomunil on adhesive properties of buccal epithelium of healthy donors, and carry out comparison of this parameter during use of other bacterial products. MATERIALS AND METHODS: Various amounts of bacterial ribosomal proteins, Escherichia coli (serotype O127:B8) and one-day Staphylococcus aureus (strain 5983) culture supernatant were added to "buccal epitheliocytes--candida" system and incubated. Buccal cells were washed after the incubation from non-bound candida and differentiated microscopically by the amount of cells with various levels of candida adhesion. Separate effect of ribosomal proteins on buccal cells and candida was studied, as well as their impact on the production of secretory products of buccal cells. RESULTS: Buccal epitheliocytes in control adhered on average 14.6 candidiasis cells. After incubation with bacterial ribosomal proteins the index decreased by 2.3 +/- 0.2 times. During separate addition of ribomunil to buccal cells and candida, ribosomal bacterial proteins were shown to have effect only on epitheliocytes. Activity of ribosomal proteins had a selective character, as shown by the lack of effect under the influence of S. aureus supernatant on buccal cells as well as an increase of adhesion under the influence of lipopolysaccharide on epitheliocytes. Viability of cells in all the cases remained at a level of 90 - 98%. Buccal cells during contact with ribomunil produced a complex of soluble mediators that took part in its blocking effect. CONCLUSION: The increase of stability of mucosal tract to microbial adhesion is an element of innate immunity and may be one of the components of immune-protecting effect of bacterial ribosomal proteins.

[Neutrophils and bacterial biofilms: dialectics of relationship].

The review is dedicated to the problem of interaction of human neutrophils with bacterial biofilms that complicate the course of infectious process. Neutrophils being the most important effectors of innate immunity may attack bacterial biofilms causing their rejections and damage of biofilm microbes. Mechanisms of neutrophil-dependent destruction of biofilms are analyzed in the review. Variants of defense of biofilm bacteria from phagocytosis that are used by them for evading neutrophils and consolidation of biofilm structures are discussed.

[Pseudomonas aeruginosa: characteristics of biofilm process].

Definition of the biofilm process as one of the types of intercellular bacterial communications is presented. The modern data concerning the structure of the Pseudomonas aeruginosa biofilm matrix and genetic mechanisms necessary for its production are described. Active and passive rejections of biofilm bacteria, which are the basis of bacterial spreading to new surfaces, are discussed. The complexity and chain type of the reactions associated with biofilm formation are emphasized.

[Interspecies interaction of bacteria and the formation of mixed (polymicrobial) biofilm].

Natural biofilms rarely exist as monocultures. Usually they are formed from various microorganism species that interact with each other, have shared metabolites, strengthen the attachment of each other to the support substrate, provide expression of "foreign" genes etc. Material on factors and mechanisms that determine the formation of mixed (polymicrobial) biofilms is analyzed in the review. The significance of interspecies interaction between bacteria based on QS system signal autoinductors is underlined. Examples of humoral and contact communications between bacteria and eukaryotes including host cells are provided. Study of polymicrobial processes and their interaction with innate and adaptive immune response seems important for further development of medical microbiology (especially regarding chronic infectious diseases).

[Staphylococcal biofilms: structure, regulation, rejection].

Staphylococci are able to cause chronic (persistent) infections, which develop in native tissues as well as on invasive materials artificially introduced into an organism. Such infections are associated with formation of biofilms. The review determines the definition of biofilms, describes factors, which contribute to their formation, characterizes adaptive stability of staphylococcal biofilms, which provides their long-term persistence in host organism. Genetic organization and regulation of polysaccharide and protein biofilms of staphylococci are described. Strategy for prevention and treatment of staphylococcal biofilm diseases is discussed.

[Role of nuclear factor-kappaB in providing interactions of human neutrophils and epithelial cells from oral cavity with Candida albicans].

Contribution of intracellular signal pathways associated with nuclear factor kappaB (NF-kappaB) in realization of interactions of human neutrophils and epithelial cells from oral cavity with Candida albicans was studied. Supression of NF-kappaB in epitheliocytes resulted in decreased adsorption of C. albicans to buccal cells (buccal mucosa). Inhibition of NF-kappaB led to decrease in receptor-dependent oxidative activity of neutrophils in systems with native and IgG-opsonized C. albicans as well as to increase of phagocytic activity during contact with C3b-/iC3b-opsonized C. albicans. It has been concluded that NF-kappaB participates in regulation of specific interactions of neurophils and epitheliocytes with C. albicans.

[Antiadhesive effect of the secretion of the oral cavity in the system "Candida albicans--buccal epitheliocytes"].

The influence of the oral cavity secretion on adhesive reactions in the system "C. albicans--buccal epitheliocytes" was studied. The treatment of C. albicans with natural saliva led to decrease of adhesive activity. The treatment of C. albicans with antibody absorbed saliva at different temperature conditions led to different changes of adhesion. This effect was determined by the action of temperature-dependent and temperature-independent factors, supposedly of enzymatic nature.

[Influence of staphylococcal metabolites on adhesive reactions in the system "Candida albicans-buccal epitheliocytes"]. / Vliianie metabolitov stafilokkov na adgezivnye reaktsii v sisteme "Candida albicans-bukkal'nye epiteliotsity".

The influence of S. aureus and S. epidermitidis metabolites on the adhesive reactions in the system "C. albicans-buccal epitheliocytes" was studied. The study revealed that the treatment of C. albicans with S. aureus supernatants inhibited the adhesion of C. albicans to epitheliocytes, the degree of the inhibiting action of S. aureus supernatants in the system depending on their strain specificity. S. epidermitidis supernatants produced no adhesive effect. The irreversible decrease of the adhesive activity of C. albicans under the action of bacterial metabolites was, seemingly, the consequence of transformation of the receptor apparatus of C. albicans. At the same time S. aureus supernatants produced no essential influence on the adhesive potential and viability of buccal epitheliocytes.

[Reactivity of Candida albicans in the system of the alternative way of complement activation]. / Reaktivnost' Candida albicans v sisteme al'ternativnogo puti aktivatsii komplementa.

The neutrophil-stimulating activity of C. albicans before and after opsonization in the system of the alternative way of complement activation (AWCA) was studied. The study revealed that, in comparison with zymosan, C. albicans exhibited a considerably lower index of AWCA-dependent opsonic effect in reaction with neutrophils. This did not correlate with the capacity of substrates to activate the alternative cascade and with the intensity of phagocytosis. The suggestion on the involvement of C. albicans thermolabile cell-wall components into the negative regulation AWCA-dependent opsonic effect was substantiated.

[A method for measuring the strength of adhesion of Candida albicans on epithelial cells]. / Sposob otsenki prochnosti adgezii Candida albicans na épiteliotsitakh.

A method on estimation of Candida albicans adhesion to epitheliocytes is proposed. The principle consists in the fact that while centrifuging epitheliocytes (1000 cycles/min, 10 min) with adhered Candida albicans through phycoll-verografin (1.077 g/cm3 density), Candida albicans cells having poor adhesion are separated from epitheliocytes trying to rise to the surface of phycoll-verografin. Candida albicans strongly adhered to epitheliocytes settle down to the bottom of test tube. In experiments with buccal epitheliocytes of healthy donors the number of strongly adhered Candida albicans ranged from 13% to 50% and they amounted to 37.0 +/- 7.8% on an average.

[Phenomenon of selective decrease of colonization (adherence) resistance in the system "Candida albicans-buccal epithelial cells"]. / Fenomen izbiratel'nogo oslableniia kolonizatsionnoi (adgezivnoi) rezistentnosti v sisteme "Candida albicans-bukkal'nye épiteliotsity".

In the period of the exacerbation of bronchial asthma an increased adhesiveness (in vitro) of buccal epithelial cells to C. albicans was noted in most children under study (94.7%). This phenomenon was not observed in children with the exacerbation of gastroduodenitis. The characteristics of natural bacterial colonization of buccal epithelium were equally decreased in both groups of patients. These results are regarded as the consequence of the reactive involvement of the epithelium of mucoid tract in the processes destabilizing homeostasis.

[TT (TTV) Virus]. / Virus TT (TTV).

Characterization of TT virus (TTV), the history of its discovery, taxonomy and identification are reviewed as update on the diagnostics of TTV infection with PCR. The variability of the virus and resulting difficulties in the selection of a TTV DNA fragment for amplification are described. Data on the virus prevalence, replication and persistence are given. The pathogenetic importance of TTV is discussed with the account of different concepts.

[An opsonin-independent strain of Staphylococcus epidermidis]. / Opsoninnezavisimyi shtamm Staphylococcus epidermidis.

Human neutrophils, subjected to stimulation under different conditions (phorbol myristate acetate, opsonized zymosan, formylmethionyl-leucinephenylalanine, nonopsonized staphylococci), produced a factor (denoted as clumping factor, or CF) with a capacity for highly selective clumping and opsonization of staphylococci. Out of 68 strains of different species of staphylococci, only a single strains (S.epidermidis) was sensitive of CF. CF negative staphylococci were capable of inducing the release of CF by neutrophils, but were not bound by this factor. Extracts, obtained by the mechanical destruction of neutrophils (sonication, repeated freezing and thawing), had no clumping activity. CF had a mol. wt. exceeding 100 kD, was positively charged and disintegrated at 100 degrees C. The capacity of S.epidermidis 178 M for binding CF completely disappeared after the treatment of bacteria with pronase and partially disappeared after boiling and treatment with trypsin and periodate. Neuraminidase and heating at 80 degrees C produced no effect. These data are the first demonstration of highly selective (strain-specific) interaction between secretory products of neutrophils and bacteria.

[Reactivity to staphylococcal peptidoglycan in the neutrophil-endothelium system]. / Reaktivnost' k peptidoglikanu stafilokokkov v sisteme "neitrofil--éndotelii".

The influence of S. aureus peptidoglycan on the process of adhesion in the neutrophil-endothelium system was studied. General regularities of this reaction, as well as the discrete action of peptidoglycan on each of its components were studied. The conclusion was made that S. aureus peptidoglycan was capable of enhancing the adhesiveness of both neutrophils and endotheliocytes. The adhesiveness of peptidoglycans of different staphylococcal species in adhesive reactions of neutrophils and endotheliocytes was manifested to a different degree. The possible mechanisms of the stimulating effect of peptidoglycans is discussed.

[Secretion of membrane-bound serine proteinases by polymorphonuclear leukocytes during adhesion to various types of receptor-dependent and receptor-independent sorbents]. / Sekretirovanie serinovoi sviazannoi s membranoi proteinazy polimornoiadernymi leikotsitami v usloviiakh adgezii na razlichnykh tipakh retseptorzavisimykh i retseptornezavisimykh sorbentov.

A high level of the membrane-bound proteinase (LMP) secretion by human polymorphonuclear leukocytes (up to 680 nmol/min/ml with N-benzoyl-L-arg-EE as a substrate) was shown during the cell adhesion to receptor-dependent (immobilized aggregates of IgG and C3b) and receptor-independent (DEAE-Sephadex and polymethyl methacrylate) absorbents. Incubation medium contained 6.10(6) cells/ml. The rate of secretion reached the maximal level during 15 min although its level was already high to the 5 min of C3b- and hydrophobic surface-induced activation (491 +/- 55 and 382 nmol/min, respectively). The high level of LMP secretion coincided with the peak of luminol-dependent chemoluminescence during the receptor-dependent adhesion, but did not correlate with a low level of luminescence in the receptor-independent adhesion. Localization of LMP in latent form in neutrophil membrane was shown earlier; the enzyme activation may occur due to effect of polycationic molecules of bovine tissue proteinase inhibitor of Kunitz type, protamine sulfate, alkaline fraction of ampholines. The enzyme (with BAEE as a substrate) was identified as serine proteinase of the trypsin-like type which activated Hageman factor (the XII factor of clotting system) and demonstrated the kininogenase activity. Only slight elastase-like activity was detected after incubation of neutrophils with all the adsorbents studied (0-2 nmol/min/ml with MeOSucAlaAlaProValpNA as a substrate). Chymotrypsin-like activity achieved maximum only by 30 min of activation with all the types of adsorbents (up to 270 nmol/min/ml with N-benzoyl-Tyr-EE as a substrate); this suggests impairment of azurophilic granules and appearance of cathepsin G.(ABSTRACT TRUNCATED AT 250 WORDS)