[Macrophage apoptosis as a mechanism of pathogenic effect of diphtheria infectious agent].

AIM: Study of the apoptogenic effect of Corynebacterium diphtheriae toxigenic strains on mice peritoneal macrophages in vitro. MATERIALS AND METHODS: Evaluation ofapoptosis induced by Corynebacterium diphtheriae, Corynebacterium pseudodiphtheriticum, Staphylococcus aureus, Streptococcus pyogenes strains was performed by characteristic morphological changes in macrophages in smears stained by azure eosin by Romanovsky-Giemsa. RESULTS: Apoptogenic activity of diphtheria infectious agent was established to be determined by diphtheria exotoxin at early (after 1 hour) and surface structures and pathogenicity enzymes at later (3 hours) stages of effect. CONCLUSION: The ability of diphtheria infectious agent to cause macrophage apoptosis is one of the mechanisms of realization of its pathogenic properties determined by the effect of diphtheria exotoxin, as well as its surface structures and pathogenicity enzymes. The increase of apoptogenic activity of toxigenic strains of C. diphtheriae in association with S. pyogenes may be a pathogenetic base of formation of prolonged forms of bacteria carriage against the background of chronic ENT pathology.

[Effect of neutrophilokines on functional activity of macrophages during formation of immunity against cholera].

AIM: To study effect of neutrophilokines on functional activity of macrophages (Mph) during formation of immunity against cholera. MATERIALS AND METHODS: In order to obtain peritoneal neutrophils (Nph), 2 ml of 0.1% glycogen solution in buffered with phosphates sodium chloride solution was administered intraperitoneally to 100 outbred mice. Vibrio cholerae 1130 in dose 10 microbial cells/Nph and cholera toxin (CT) in dose 1 or 10 mcg/ ml were used as inducers of neutrophilokines synthesis. Obtained neutrophilokines were assessed on their effect on phagocytic activity of Mph, resistance of these cells to cytotoxic and apoptogenic effects of Vibrio cholerae and CT as well as effect on lysosomal apparatus of Mph. RESULTS: It was established that neutrophilokines induced by Vibrio cholerae and CT stimulate killer activity of Mph and lability of their lysosomal membranes, and suppress programmed death of these cells. CONCLUSION: Results of studies revealed immunoregulatory activity of neutrophilokines relative to Mph and demonstrated ability for cooperation between mono- and polynuclear phagocytes mediated by cytokines and, in particular, neutrophilokines.

[Evaluation of the immunoregulatory activity of neutrophilokine fractions in a macrophage model].

A procedure was proposed to evaluate the immunoregulatory activity of neutrophilokine fractions on a model of macrophages. It was established that all the fractions studied did not affect the absorptive capacity of these cells in both primary and secondary immune responses. At the same time, the majority of neutrophilokine fractions modulated the killer activity of macrophages: they potentiated or inhibited it. The proposed procedure for evaluating the regulatory effect of individual neutrophilokine fractions on a model of studying the killer activity makes it possible not only to characterize their activity, but also to identify helper and suppressor fractions, which discloses approaches to correcting an immune response by means of these fractions.

[Influence of neutrophilokines on population and subpopulation repertoire of lymphocytes and their functional activity during immune response against plague].

Results of experimental study of regulatory effect of nutrophilokines induced by Yersinia pestis EV strain on population and subpopulation repertoire of lymphocytes and their functional activity during immune response against plague infection are presented. It was established that these neutrophilokines stimulate CD4+ and suppress CD8+ lymphocytes. Helper effect of neutrophilokines on functional activity of lymphocytes was more pronounced during secondary than during primary immune response.

[Role of cholera toxin-induced apoptosis in alteration of macrophages in mice].

AIM: To study the role of active programmed cell death induced by Vibrio cholerae antigens in alteration of peritoneal macrophages of experimental animals. MATERIALS AND METHODS: Apoptosis was assessed by cytofluorometric analysis with propidium iodide using cytofluorometer "Coulter" as well as on characteristic morphological changes of cells in stained histological preparations. RESULTS: Performed experiments carried out by both methods provide evidence that V. cholerae and its antigens (cholera toxin, neuraminidase, chitinase, and lypopolysaccharide) cause apoptosis of mice peritoneal macrophages, which leads to their alteration. CONCLUSION: Our results demonstrate that programmed cell death of phagocytes is one of the causes of cytotoxic effect of V.cholerae and its antigens. Performed experiments show the role of apoptosis of macrophages in formation of postimmunization immunosuppression after vaccination against cholera.

[Preparation of fractions and characteristic of neutrophilokines complex induced by Yersinia pestis EV].

Biochemical and immunobiologic characteristics of fractions of neutrophilokines during primary and secondary immune response against plague infection are presented. Fractions were obtained using gel chromatography from neutrophilokines complex induced by vaccine strain of Yersinia pestis. It was revealed that fractions of neutrophilokines regulate IL-2 synthesis by Th1-helpers, IL-4 and IL-5 synthesis by Th2-helpers and also expression of IL-2 receptors by immunocompetent cells. Helper effect of neutrophilokines' fractions was more pronounced during secondary immune response.

[Apoptosis of phagocytes as one of the probable mechanisms of the pathogenetic action of Yersinia pestis "mouse" toxin].

Apoptosis was evaluated by characteristic morphological changes of cells in preparations stained with histological dyes and in live preparations, as well as by DNA degradation, colorimetrically detected with the use of the diphenylamine reagent. "Mouse toxin" (MT) was found to have a pronounced apoptogenic action with respect to the phagocytic cells of mice, but not guinea pigs. Macrophages were affected by this action stronger than neutrophils, and in both cases this effect was dose dependent. As the dose of MT decreased to 0.01 microg/ml, the proportion of cells dying as the result of apoptosis increased, the necrotic type of damage was almost absent. On the contrary, as MT concentration rose to 1.0 microg/ml and over, the proportion of phagocytes dying due to necrosis increased with a decrease in the number of cells in which the process of apoptosis started. The results of the study are indicative of the fact that the mechanisms programming the death of cells under the action of MT on macrophages and neutrophils took part in the process, which, in its turn, determined their role in the pathogenesis of plague.

[Influence of neutrophilokines on the synthesis of lymphokines in the process of the formation of immunity to plague].

The evaluation of the complex of neutrophilokines whose synthesis was induced by Yersinia pestis vaccine strain EV on the production of lymphokines in the process of the formation of primary and secondary immunity to plague is presented. As revealed in this study, neutrophilokines regulate the synthesis of IL-2 by T helpers of type 1, IL-4 and IL-5 by T helpers of type 2, IL-1 by B lymphocytes, as well as the expression of receptors IL-2 by immunocompetent cells. The helper effect of neutrophilokines is more pronounced in the secondary immune response.

[Comparative evaluation of mono- and neutrophilokins inducing activity of Yersinia pestis antigens]. / Sravnitel'naia otsenka mono- i neitrofilokinindutsiruiushchei aktivnosti antigenov Yersinia pestis.

The results of the comparative analysis of the cytokine inducing activity of Yersinia pestis EV antigens are presented. Y. pestis fraction 1A (F1A) and lipopolysaccharide (LPS) were shown to induce mono- and neutrophilokines, regulating cooperative interaction of phagocytes in the process of immunity formation to plague. Neutrophilokines and monokines exceed in their capacity for inducing F1A such acknowledged inductor as Escherichia coli LPS. As revealed by the comparative evaluation of Y. pestis EV LPS and E. coli LPS, neutrophilokines synthesized under the action of the former preparation, have greater influence on the inhibition of the macrophage migration from the infection focus as well as on digestive activity of these cells (in secondary immune response) and on the labilization of the lysosome membranes of macrophages than neutrophilokines induced by E. coli LPS. At the same time they produce a lesser modulating effect on the killer and chemotactic activity of neutrophils, as well as on the expression of FC receptors (FcR) on their surface in comparison with monokines, synthesized under the influence of E. coli LPS.

[Cholera toxin as Vibrio cholera superantigen]. / Kholernyi toksin--superantigen Vibrio cholerae.

Experimental data confirming our earlier suggestion, that cholerae toxin (CT) possesses superantigen (SA) properties are presented. When used in very small doses, CT has been found to induce polyclonal activation of T lymphocytes, essentially exceeding that observed in classical T mitogens characteristic of SA. CT, in contrast to mitogens and similarly to other SA, is shown to display this activity only in the presence of antigen-presenting cells. Experiments with the use of monoclonal antibodies to the variable region of the beta-chain of the T-cell receptor (V beta TCR) have demonstrated that CT, similarly to other SA, are capable of inducing expression of certain types of V beta TCR and causing polyclonal activation of T lymphocytes carrying these types of V beta TCR. The presence of these properties gives grounds for regarding CT as SA. The SA activity of CT has been found to be linked with its subunit A.

[Effect of monokines induced by Yersinia pestis EV on the functional activity of neutrophils during development of antiplague immunity]. / Vliianie kompleksa monokinov, indutsirovannykh Yersinia pestis EV, na funktsional'nuiu aktivnost' neitrofilov pri formirovanii protivochumnogo immuniteta.

A study was made of the Yersinia pestis EV induced monokine complex influence on neutrophil (Nph) functional activity in the course of antiplague immunity formation. The obtained monokines essentially enhance Nph killing, chemotactic activities and Fc-receptor expression, and stimulate lysosome membrane labilization of these cells. The helper effect of the Y. pestis EV induced monokines on Nph functional activity is more pronounced during the secondary immune response, than in the course of the primary one.

[Comparative evaluation of the neutrophilokine-inducing activity of Yersinia pestis EV and Escherichia coli lipopolysaccharides]. / Sravnetel'naia otsenka neitrofilokinindutsiruiushchei aktivnosti lipopolisakkharidov Yersinia pestis EV i Escherichia coli.

As shown in this study, neutrophilokine-inducing capacity of Y. pestis EV lipopolysaccharide (LPS) was not inferior to, and in secondary immune response even exceeded, that of E. coli LPS. Neutrophilokines synthesized under the action of the former preparation produced greater influence on the inhibition of macrophage migration from the focus of infection, the phagocytic activity of these cells (in secondary immune response) and the labilization of the lysosomic membranes of macrophages than neutrophilokines induced by E. coli LPS. Only in primary immune response the digestive capacity of macrophages was more actively stimulated by neutrophilokines induced by E. coli LPS. Both preparations did not induce the secretion of neutrophilokines regulating the expression of Fc-receptors on the surface of macrophages.

[Cytokines--a general system of homeostatic regulation of cell functions]. / Tsitokiny--obshchaia sistema gomeostaticheskoi reguliatsii kletochnykh funktsii.

The paper reviews biological characteristics of cytokines, which are short living molecules exerting pleiotropic and redundant effects on a variety of target cell types, influencing cell activation and differentiation. Significance of cytokines for patho- and immunogenesis of infections and other diseases is analysed, in addition to further perspectives of cytokine employment for prophylaxis and treatment of various diseases.

[Monokine-producing activity of human monocyte-like cell line U937 induced by Yersinia pestis EV antigens]. / Monokinprodutsiruiushchaia aktivnost' monotsitopodobnoi linii kletok cheloveka U937, indutsirovannaia antigenami Yersinia pestis EV.

The data on a study of the monokine-producing ability of human monocyte-like cell line U937 are presented. Antigens of Yersinia pestis EV (lipopolysaccharide and fraction 1A) induce monokine production by cell line U937. The obtained monokines essentially enhance neutrophil killer and chemotactic activities, stimulate FcR expression, increase the number of lysosomes, and the lability of lysosomal membranes in neutrophils. F1A significantly suppresses LPS in respect to the ability to induce monokine production, which stimulate neutrophil functional activity.

[A method of assessing immunogenicity of preparations for plague prevention]. / Sposob opredeleniia immunogennosti preparatov dlia profilaktiki chumy.

A rapid, economic, and simple method for assessing the immunogenic properties of preparations for plague prevention is proposed. It is based on amplification of the bactericidal activity of peritoneal macrophages of experimental animals in the course of forming antiplague immunity. The increase in intracellular killing was assessed by the index of macrophage activation, which permits a tentative assessment of the immunogenic properties of the agent. This method is 6 times more rapid and requires 5 times less animals than routine methods and involves no manipulations with virulent strains of Yersinia pestis.

[The cytokine-inducing activity of the Yersinia pestis "murine" toxin]. / Tsitokinindutsiruiushchaia aktivnost' "myshinogo" toksina Yersinia pestis.

In this work the data obtained in the study of cytokinin-inducing activity of Y. pestis "mouse" toxin (MT) are presented. The study revealed that MT induced the synthesis of IL 1, IL 2 and TNF alpha. The most pronounced activity in MT was IL 2 inducing activity having dose-dependent character: the effect increased with the decrease of the dose of the preparation. The maximum level of the synthesis of IL 2 was observed when very low doses of the preparation (0.01 microgram/ml) were used, which was characteristic of superantigens. The presented data suggest that IL 2 plays an essential role in the mechanism of immunopathological reactions stipulated by MT.

[The effect of a modification to the lipopolysaccharide of Yersinia pestis on its neutrophilokine-inducing activity]. / Vliianie modifikatsii lipopolisakharida chumnogo mikroba na neitrofilokin-indutsiruiushchuiu aktivnost'.

The ability of the isolated and modified Yersinia pestis LPS to induce the synthesis of the neutrophilokines that regulate the macrophage functional activity was studied. It is established that the Y. pestis LPS detoxication, especially by the method of deacylation, does not lead to the decrease in biological, in particular neutrophilokine-inducing activity of these preparations, but actually even increases it. These results are in agreement with many reports showing the possibility of decreasing the LPS toxicity without reducing immunostimulatory activity of this important component of the outer membrane of gram-negative bacteria.

[The evaluation of the efficacy of immunization against plague by the modulation in the index of the macrophagal transformation of of the peripheral blood monocytes]. / Otsenka éffektivnosti immunizatsii protiv chumy po moduliatsii pokazatelia makrofagal'noi transformatsii monotsitov perifericheskoi krovi.

The subcutaneous and aerogenous immunization of experimental animals with live dried antiplague vaccine has been shown to modulate the macrophagal transformation index of peripheral blood monocytes (PBM) which correlates with the resistance of the animals to the causative agent of plague. This finding allows to recommend the use of PBM for the evaluation of the effectiveness of immunization with antiplague vaccine.

[A new method of assessing plague immunity in humans]. / Novyi metod otsenki protivochumnogo immuniteta u liudei.

Subcutaneous and aerogenic vaccination of humans with live dry vaccine may be assessed using a new test: index of macrophageal transformation of peripheral blood monocytes. In addition, this method will help choose the optimal dose of vaccine.