Inhibitory Effect of Copper and Zinc Ions on the Growth of Streptococcus pyogenes and Escherichia coli Biofilms.

Analysis of the effect of copper and zinc ions on Streptococcus pyogenes and Escherichia coli biofilms revealed significant differences in the effect of these metals in the form of sulfates or chlorides on biofilm formation. Zinc ions in low doses (salt concentration 0.005 M) inhibited the growth of S. pyogenes biofilms by 1.5 times. After increasing salt concentration to 0.05-0.5 M, the growth of biofilm was reduced by 2.5 times in comparison with the positive control. In case of E. coli biofilms, the inhibition was more pronounced: zinc sulfate in a concentration of 0.005 M reduced its growth by 4.6 times in comparison with the positive control. After increasing salt concentration, the growth of E. coli biofilm decreased by 6.8 times. In case of zinc chloride, zinc ions produced weaker effect and reduced biofilm growth by 2.2 and 5 times, respectively. Copper salts in a concentration of 0.005 M had practically no effect on the growth of S. pyogenes biofilm; with increasing salt concentration, the degree of inhibition was close to the effect of zinc. In case of E. coli biofilm, we observed a slight inhibition of the growth by low doses of copper ions (by 1.4-1.3 times); with increasing salt concentration the effect increased by 5.6 and 2.2 times for copper sulfate and chloride, respectively. Copper and zinc cations had no effect on mature biofilm.

[Deceleration of bacterial growth in Staphylococcus aureus and Pseudomonas Aeruginosa cultures in the presence of copper and zinc cations].

AIM: Evaluate antibacterial effects of millimole concentrations of copper and zinc cations used as sulfates or chlorides in S. aureus and P. aeruginosa cultures. MATERIALS AND METHODS: Suspension of S. aureus or P. aeruginosa containing 108 CFU/ml were lawn-seeded onto Petri dishes with nutrient agar. 30 minutes later salt solution of copper or zinc with concentrations by metal cation from 10(-9) or 10(-6) M to 5 x 10(-1) M were applied to the surface of the lawn by 5 µ drops using a 36-channel stamp-replicator. Dishes with bacterial cultures were then incubated for 16-18 hours at 37°C, and diameter of growth inhibition zone was measured afterwards. For evaluation of the presence (absence) ofviable bacteria in growth inhibition zones, seeding of the material from the center of the zone was carried out into tubes with nutrient broth that were thermostated up to 5 days at 37°C, clarity of the nutrient broth was then evaluated. RESULTS: Inhibiting effects of zinc sulfate against S. aureus surpass effects of copper sulfate by 1.3-1.6 times (p < 0.001-0.05) within metal concentrations from 50 to 500 MM. The effects of zinc chloride in S. aureus culture surpass effects of copper chloride by 1.2-1.6 times (p < 0.02) for cation concentrations of 100 and 500 mM. In P. aeruginosa cultures, antibacterial effects of copper sulfate are comparable with effects of zinc sulfate. The effects of copper chloride on P. aeruginosa cells are 1.2 times more pronounced (p < 0.05) than effects of zinc chloride for metal concentration of 500 mM. Material seeding from zones of culture growth suppression detects turbidity of nutrient broth in samples with specimens from wells treated with zinc salts and broth clarity in samples from wells treated with copper salts. CONCLUSION: In millimole con- centrations, copper and zinc cations have pronounced antibacterial effects in cultures of S. aureus and P. aeruginosa. It is realized as bactericidal in the presence of copper cations and bacteriostatic - in the presence of zinc cations. S. aureus bacteria turn out to be more sensitive to the effects of zinc cations, evaluated by zones of growth inhibition, than P. aeruginosa. The latter show a higher, than S. aureus, tolerance to copper and zinc. Wherein, P. aeruginosa toler- ance to copper cations is surmountable.

[Effects of copper and zinc cations bound by gamma-globulin fraction in Staphylococcus aureus culture].

UNLABELLED: AIM. Evaluation of Staphylococcus aureus culture growth dynamics in the presence of gamma-globulin: metal-complexes formed with copper and zinc cations as well as cations of metals used in isolation during the first 24 hours of exposition. MATERIALS AND METHOD: . Samples of human gamma-globulin metal-complexes with copper or zinc cations at a final concentration of 0.5 microg/ml were introduced into S. aureus bacteria suspensions containing approximately 10(3) CFU/ml. Suspension at the volume of 5.0 ml was incubated at 37 degrees C for 24 hours with sampling and CFU calculation in the culture at various exposure periods. An accepted micromethod for determination of viability of bacteria was used. RESULTS: The protein transformed by copper cation binding realizes bacteriostatic activity in the logarithmic growth phase of S. aureus culture from 3.0 to 6.0 hours of incubation. Free copper cations inhibit bacterial reproduction at a higher degree than the metal-complex. The protein transformed by zinc cation binding realizes bacteriostatic activity at 1.5 hours of S. aureus incubation. Free zinc cations do not have bacteriostatic effect against S. aureus. CONCLUSION: Proteins of the gamma-globulin fraction in the range of physiological concentrations forming metal-complexes with copper and zinc cations may be factors that have cytostatic effect against S. aureus bacteria. Zinc cations realize bacteriostatic activity only in gamma-gloulin bound state whereas copper cations--also in the free state.

γ-Globulin fraction proteins and their metal complexes with copper cations in induction of IL-8 production.

Plasma γ-globulin fraction proteins, copper cations, and metal complexes formed by copper cations with human serum γ-globulin induce the production of up to 4.0 ng/ml IL-8 by human blood cells. Protein modified by copper cations is 1.3-1.7-fold (p < 0.001-0.01) more potent than control γ-globulin and 1.3-fold (p < 0.001) more potent than copper cations alone. Analysis of the time course of IL-8 production demonstrated that IL-8 is produced as a prolonged or delayed response cytokine under conditions of this induction.

Induction of TNF-α production by metal complexes of γ-globulin fraction proteins and copper and zinc cations.

Plasma γ-globulin fraction proteins, copper and zinc cations, and metal complexes of these cations and human serum γ-globulin induce the production of TNF-α by human blood cells. The protein modified by zinc cations is by 1.4-1.7 times more potent (p<0.001-0.01) than control γ-globulin in inducing the production of TNF-α, while metal complex formed by γ-globulin and copper is by 1.9-2.2 times more potent that the control protein (p<0.001). Under conditions of experimental induction, TNF-α is produced as a typical early response cytokine. During long-term incubation, copper cations lose the ability to induce TNF-α production, while in combination with γ-globulin these cations produce a synergistic effect with the control protein.

Production of early IL-1ß induced by human serum γ-globulin metal complexes.

Plasma γ-globulin fraction proteins, copper and zinc cations, and metal complexes formed by them with human serum γ-globulin induce the production of early (24-h incubation) IL-1ß by human blood cells. The protein modified by Zn cations 1.2 times more actively (p<0.01) induced early IL-1ß than the control γ-globulin, while γ-globulin metal complex with copper was 1.4 times less active (p<0.1) than the control protein. The regularities of induction changed over the course of 48-h incubation: zinc cations chelated by γ-globulin fraction protein reduced, while copper cations stimulated the realization of the protein induction potential in the metal complex.

Mouse splenocyte blast transformation in the presence of plasma γ-globulin fraction proteins and their complexes with copper and zinc.

Plasma γ-globulin fraction proteins, copper and zinc cations, and metal complexes formed by these cations and human serum γ-globulin induce blast transformation of splenocytes from BALB/c mice at a level comparable to that induced by concanavalin A. Zinc bound to γ-globulin reduces by 25% and copper in complex with this protein stimulates by 1.6 times its capacity to induce blast transformation. Combinations with concanavalin A reproduce the effects of γ-globulin-metal complex under conditions of mitogen induction. Incorporation of(3)H-thymidine in splenocytes incubated with combinations of γ-globulin-copper metalcomplex, copper cations, and control protein with concanavalin A was by 1.4, 1.3 (p<0.1), and 1.25 times higher (p<0.05), respectively, than after incubation with concanavalin A alone.

Production of late IFN-α induced by plasma γ-globulin fraction proteins and their metal complexes.

Plasma γ-globulin fraction proteins, copper and zinc cations, and metal complexes they form with human serum γ-globulin induce the production of IFN-α by human blood cells throughout the periods of up to 72 h. Zinc cation-modified protein by 1.6 times (p<0.05) more actively induces late IFN-α than the control γ-globulin; γ-globulin-copper metal complex is 2-fold (p<0.002) more effective than the control protein. The results indicate that functional relationships between the components inducing the production of late IFN-α differ from the effects realized during the early period of induction.

Binding of zinc cations to human serum gamma-globulin.

Binding of zinc cations to human serum gamma-globulin was studied by molecular ultrafiltration. The content of free metal in the filtrate was evaluated by reaction with o-phenanthroline. Conformation characteristics of the protein were determined by UV spectrophotometry. Our findings suggest that gamma-globulin molecule contains several zinc binding sites differing by corresponding constants and successively occupied with increase in the content of bound metal. The parameters of zinc binding correspond to those obtained in experiments with copper. Conformation status of protein with bound zinc differs significantly from that of protein with bound copper cations.

Preparation of specimens of human serum gamma-globulin modified by copper and zinc and its immunochemical characteristics.

Specimens of human serum gamma-globulin modified by molar excess of copper and zinc cations were obtained by molecular ultrafiltration. Conformation characteristics of the protein were determined by UV spectrophotometry. Immunochemical study included radial immunodiffusion test and direct and sandwich enzyme-linked immunosorbent assay. After binding of copper and zinc, the gamma-globulin molecule underwent conformation changes modifying presentation of antigenic determinants on the globule surface and their availability for recognition by specific antibodies. The effects of copper were much more pronounced than those of zinc cations.

Reactions between human serum gamma-globulin and zinc cations.

Interactions of human serum gamma-globulin with zinc cations in solution were studied by differential spectrophotometry in UV light. Supraphysiological concentrations of zinc caused an increment in optical density of protein solution reflecting the effect of gamma-globulin saturation with the metal. Zinc concentrations below physiological led to hypochromism in the protein absorption spectrum. Conformation changes in gamma-globulin during interactions with zinc are analyzed for the surface and intramolecular binding sites and are compared with the effects of copper cations.

Biphasic interaction of gamma-globulin with copper cations.

Interactions of human serum gamma-globulin with copper cations in solution were studied by differential ultraviolet spectrophotometry. Copper in supraphysiological concentrations increases optical density of protein solution, reflecting the effect of gamma-globulin saturation with metal. In physiological and lower concentrations of copper cations we observed hypochromia in the protein absorption spectrum. Conformational changes in g-globulin molecule during interactions with copper by the surface and intramolecular binding sites and possible role of bivalent metal cations in the maintenance of certain conformations of immunoactive serum proteins are discussed.

[The capacity of fusicoccin for inducing the synthesis of early interferon].

The response of human and animal cells to the action of fusicoccin (FC), a fungal metabolite with phytohormonal properties, was evaluated. The capacity of FC for inducing the synthesis of early interferon (IFN), supplied into the blood serum of common white mice, and for enhancing the natural cytotoxic activity of human lymphocytes in vitro was established. The metabolism of actively proliferating monocytic leukemia cells J-96 and human ovarian carcinoma cells CaOv, as well as mouse fibroblasts L-929, was found to be inhibited under the in vitro action of FC. The common character of the mechanisms of action of FC and IFN having antiproliferative and immunomodulating activity is discussed.

Formation of supramolecular aggregations of gamma-globulin as a metal-dependent process.

The presence of copper cations in the solution of human serum gamma-globulin induced the formation of supramolecular forms of the protein. The intensity of this reaction increased with increasing copper concentration. The mechanisms of g-globulin aggregate formation under normal conditions and the possible role of bivalent metal cations in the regulation of protein effector functions are discussed.

[Capacity of fusicoccin for inducing the production of early interferon].

The response of human and animal cells to the action of fusicoccyne (FC), a fungal metabolite with phytohormonal properties, was evaluated. As shown by in vitro studies, FC had the capacity to induce the production of early interferon (IFN) in the blood serum of non-inbred white mice and to enhance the natural cytotoxic activity of human lymphocytes. In vitro experiments also revealed that the action of FC inhibited the metabolism of actively proliferating monocytic leukemia cells J-96 and human ovarian carcinoma cells CaOv, as well as mouse fibroblasts L-929. The common character of the mechanism of action of FC and IFN, having well-known antiproliferative and immunomodulating activity, is discussed.

Immunomodulating characteristics of Cys-(Pro)3-Glu-Leu hexapeptide under different experimental conditions.

Cys-(Pro)3-Glu-Leu hexapeptide markedly stimulated activity of human natural killers during the cytotoxic test in the presence of autologous serum, but not fetal calf serum. This effect of hexapeptide on natural killer activity was physiological. Conditions are determined under which hexapeptide stimulates the cytotoxicity in a mode ensuring protection of the microenvironment from damage inflicted by own natural killer cytotoxic factors.

Variability of natural killer activity during immunotherapy.

In patients with multiple sclerosis, chronic active hepatitis B, and relapsing genital herpes integral parameters of variability in natural killer activity were higher than in donors. In the dynamics of immunotherapy with IFN preparations (chronic active hepatitis B) and IFN inductor ridostine (relapsing genital herpes) these parameters decreased and approached the normal values. The possibility of using variability of natural killer activity for evaluation of cell function and prediction of the efficiency of immunotherapy is discussed.

Activity of human lymphocytes in the presence of carbohydrate-containing compounds.

Treatment with chelating agent abolished stimulation of human lymphocyte blast transformation observed in the presence of native microbial glycoproteins. Heparin passed through a column packed with aluminum hydroxide inhibited cytotoxic activity in natural killer cells. We discuss the possibility of regulation of cell functions via modulation of the vector of transport and exchange of metal cations in cell microenvironment and the role of macromolecular compounds containing carbohydrate components in this process.

[Endogenous biological retranslation in current clinical and biological studies]. / Problema éndogennoi biologicheskoi retransliatsii v kliniko-immunologicheskikh issledovaniiakh.

The paper generalizes the results of research implemented within the framework of the methodological concept of the Endogenous Biological Retranslation (EBR) for the purpose of finding new data about the immune pathogenesis of multiple sclerosis (MS), whose mechanisms are related with violations of the EBR processes in the body. A possibility is considered to use the priming of interferon (INF) production, as an EBR variant, for evaluating the functioning of the INF system. The thus obtained materials prove convincingly that the experimental approaches, based on priming the blood cells to the IFN production, can be clinically used in the diagnosis and therapy of MS. A new effective combined IFN-therapy scheme for the disease in question was demonstrated. A set of criteria, which makes it possible to prescribe the INF preparations for MS patients with regard for an evaluated response degree of patients' blood cells to them and with regard for a prognosticated efficacy of an assumed treatment is offered. Possibilities of an individualized comprehensive therapy for MS by using the offered experimental approaches are discussed.

[Clinico-immunological comparisons in evaluation of interferon system functioning in patients with multiple sclerosis]. / Kliniko-immunologicheskie sopostavleniia v otsenke funktsionirovaniia sistemy interferona u bol'nykh rasseiannym sklerozom.

In search for rational approach for immunotherapy individualization in patients with multiple sclerosis (MS) assigned to interferon (IFN) treatment, an evaluation of IFN-alpha and IFN-gamma production by peripheral blood leucocytes (PBL) under standard induction and exogenous IFN priming in comparison with clinical characteristics was made. Fifteen patients with MS (6 males and 9 females, aged 25-58 years) with verified diagnosis of MS were examined. IFN production priming allowed to obtain characteristics of IFN system deficiency, which could not be detected by standard induction methods. Correlation between induced and primed PBL. IFN-gamma production and MS severity, duration and course was found. Patients with no PBL blood cells dissociate response to IFN-alpha and IFN-gamma exhibited less neurological deficit than those with associations in response. A use of blood cell sensitivity to exogenous IFN in individualization of MS immunotherapy with IFN-medications is discussed.