Effects of the Linear Fragments of Beta-(1→3)-Glucans on Cytokine Production in vitro.

Beta-glucans, homopolysaccharides composed of 3,6-branching ß-(1→3)-D-glucan chains, attract great interest as inducers of cytokine synthesis. In this work, we studied the ability of linear fragments of beta-glucan chains to activate cytokine synthesis. Synthetic nona-ß-(1→3)-D-glucoside (SO) representing a linear fragment of beta-glucan chain, endotoxin (ED), and natural ß-(1→3)-D-glucan (GL) were tested for their role as inducers of cytokines in whole peripheral blood cultures collected from 17 individuals. The concentrations of IL-12p70, IFN-γ, IL-2, IL-10, IL-8, IL-6, IL-4, IL-5, IL-1ß, TNF-α, and TNF-ß were measured in the supernatants after 2, 24, and 48 h of cell culturing. SO, ED, and GL stimulated production of pro-inflammatory IFN-γ, IL-1ß, IL-2, IL-6, IL-8, TNF-α and anti-inflammatory IL-10. The highest levels of biosynthesis after stimulation with SO were registered for IL-6, IL-8, and TNF-α. SO stimulated production of all cytokines (except IFN-γ) to a lesser extent than ED and GL. The IFN-γ/IL-10 (Th1/Th2) ratios after 24 and 48 h of culturing were 3.1 and 7.5 for SO; 0.03 and 0.1 for GL; and 0.06 and 0.2 for ED, respectively. The results indicate that linear fragments of beta-glucans cause a more pronounced shift of immune response towards the pro-inflammatory (Th1) type than beta-glucan itself.

Protective activity of a glycoconjugate based on a synthetic hexasaccharide related to a fragment of capsular Streptococcus pneumoniae serotype 14 polysaccharide chain.

We studied the effects of immunization with a conjugate of carrier protein and hexasaccharide ligand related to a fragment of capsular of Str. pneumoniae serotype 14 polysaccharide chain on activation of innate and adaptive immunity. It was found that two-fold immunization with the glycoconjugate adsorbed on aluminum hydroxide significantly increased the titer of IgG antibodies to capsular polysaccharide in the blood and protected 100% mice from infection with Str. pneumoniae serotype 14. Enhanced bactericidal activity of peripheral blood lymphocytes of mice was found 4 and 24 h after the first immunization with the immobilized glycoconjugate. Adsorption of the glycoconjugate on aluminum hydroxide resulted in modification of the immune processes at the stage of activation of innate immunity and subsequent strengthening of the adaptive immunity.

[Influence of Staphylococcus vaccine on functional activity of antigen-presenting cells].

AIM: Study the influence of staphylococcus vaccine on functional activity of antigen-presenting cells. MATERIALS AND METHODS: Mice intraperitoneally received 500 µg of "Staphylovac" vaccine. Phagocytic activity of peritoneal macrophages against Staphylococcus aureus 1991 was determined in animals at various time intervals. Phagocytic index (PI) and phagocytic number (PN) in smears made at 30 and 60 minutes of incubation were calculated. Dendritic cells (DC) were obtained from bone marrow precursors during cultivation with 20 ng/ml GM-CSF and 20 ng/ml IL-4 (BioSource International Inc., Belgium). At day 6 of incubation staphylococcus vaccine (50 µg/ml) was added to immature cells for induction pf DC maturation. DC phenotype evaluation was carried out by flow cytometry using monoclonal antibodies against cell antigens (Beckman Culter, USA). RESULTS: PI at 30 and 60 minutes of incubation increased by 0.12 - 1.4 times and 1.11 - 1.52 times, respectively, compared with control. PN at 30 minutes of incubation of cells with microbial suspension increased from 8.6 to 11.4% against 5.9% in control, at 60 minutes of incubation--from 7.7 to 8.1% against 5.1% in control. In DC culture during their incubation with the vaccine, content of cells with expression of intercellular adhesion marker CD38, antigen presenting marker MHCII and DC terminal differentiation marker CD83 increased. Expression of CD34 and CD14 was also noted, that may give evidence on partial direction of cell differentiation to macrophages. CONCLUSION: "Staphylovac" vaccine during intraperitoneal administrationt to mice had activating influence on functional activity of antigen-presenting cells and peritoneal macrophages.

[Effect of aluminium hydroxide on innate immunity and immunogenicity of bacterial and synthetic antigens of Streptococcus pneumoniae].

AIM: Study the effect of aluminium hydroxide on molecular-cell mechanisms of innate immunity activation and its adjuvant effect on immunogenicity of natural bacterial and synthetic pneumococci antigens. MATERIALS AND METHODS: Surface markers of dendritic cells (DC), mononuclear leukocytes (ML) and cytokine levels were determined by flow cytometry; IgG titers--by EIA. Protective activity was evaluated in experiments with active protection of mice from infection with virulent pneumococci strains. RESULTS: Aluminium hydroxide increased the ML content of mice spleen expressing TLR2 and TLR4. Its addition into the culture of immature DC induced the appearance of a population of cells with mature DC markers--CD83, CD80, CD86, however, the level of undifferentiated cells (CD34) and cells with adhesion molecules (CD11c, CD38) did not change. DC produced IL-1ß, IL-5, IL-10, IFNγ into the cultivation medium. An increase of cytokine production took place 2 hours after the administration into mice and was retained for the observation period (24 hours). Th1 (IFNγ, TNFα) and Th2 (IL-5, IL-10, GM-CSF) cytokine production gave evidence on immune response polarization by Th1/Th2, type. After 2 administrations of aluminium hydroxide into mice the number of ML with CD19+, CD5+, NK1.1+, CD25+, MHCII+ markers increased during decrease of CD3+, CD4+ and CD8+ T-lymphocytes. Adaptive immunity activation was characterized by high IgG titers to pneumococci capsule polysaccharide and protection of 90 - 100% of the mice against infection with lethal doses of S. pneumoniae strains, was detected during 2-fold immunization of mice with conjugates of synthetic pneumococci oligosaccharides with BSA,sorbed onto aluminium hydroxide, whereas natural bacterial antigens provided 90 - 100% survival of animals during immunization without the adjuvant. CONCLUSION: Data are provided on the effect of aluminium hydroxide on key effectors of innate immunity: DC, ML, TLRs and cytokine production. A reasonable administration of this adjuvant was shown to be in association with conjugates of pneumococci synthetic oligosaccharides with a carrier protein.

[Effect of Immunovac-VP-4 and Kagocel immunotherapy on cytokine levels in patients with erythema nodosum].

Fixed erythema--a kind of clinical and histopathologic reaction, fixed drug eruption. The purpose of the study--the study of characteristics of the cytokine profile in patients with erythema and the dynamics of the basal levels of proinflammatory and antiinflammatory cytokines during immunotherapy. All 41 patients with fixed erythema at baseline and after treatment was carried out determination of levels of pro-, anti-inflammatory and regulatory cytokines in the serum by ELISA using test systems "Biosource" (Austria). In patients with fixed erythema Immunovac treatment increased serum IFN-gamma (p < 0.05), IL-1beta (p > 0.05), IL-6. While Kagocel led to an increase in IFN-gamma (p < 0.05), IL-1beta, IL-6 and reduction of TGF-beta (p < 0.05). At the same time in patients with fixed erythema basic therapy contributed to the significant increase in TGF-â and decrease in IL-10. Immunovac-VP-4 had the highest activity for the induction of IFN-gamma. Inclusion in the range of therapeutic and prophylactic measures in patients with fixed erythema immunomodulators promotes activation links innate and adaptive immunity triggers mechanisms, thus increasing the antiviral response in patients with erythema.

[Activating effect of a germanium-organic compound on immunocompetent cells during intranasal immunization of mice with a live influenza vaccine].

AIM: Detailed characteristic of results of intranasal immunization of mice with one of two variants of vaccinating influenza virus, particularly in combination with a low molecular weight germanium-organic compound (LMW-GOC). An additional aim is evaluation of effect of LMW-GOC on the parameters of immune system in case of intranasal administration of the preparation without the addition of vaccinating virus. MATERIALS AND METHODS: The study was carried out in female CBA mice (18-20 g, 6 animals per group). Intranasal immunization was carried out by 2 different variants of B/Victoria influenza virus--once or twice with a 2 week interval. Cells for study were obtained from spleen and nasal- and bronchial-associated lymphoid tissue (NALT/ BALT) 24 hours and 7 days after intranasal administration of the preparations. The main method of the study--determination of the level of expression of various markers oflymphocytes in comparison with the level of the same markers in the cells of control group animals by using flow cytometry method. The mean parameters obtained were determined by using program package WinMDI 2.8. RESULTS: The main results were the increase of level of expression of various lymphocyte markers obtained from mice after intranasal administration of the vaccines and their combination with LMW-GOC or LMW-GOC only without the participation of the vaccines. A significant increase of the expression of TLR9 marker compared with other parameters was noted. Administration to mice of wild B/Victoria strain notably more frequently conditioned the decrease of expression of some parameters compared with administration of the cold adapted strain. Effect of LMW-GOC without the vaccine also conditioned the increase of levels of markers however a combination of the preparations with the vaccine was more effective. CONCLUSION: The increase of level of expression of a number of lymphocyte markers may serve as a sign of successful intranasal vaccination against influenza. LMW-GOC preparation increases immune stimulating effect of intranasally administered vaccines and in none of the cases weakens the stimulating result of effect of the vaccines, and in many cases increases it. LMW-GOC may be studied as a main or additional adjuvant for intranasal application of influenza vaccines.

[Activation of lymphocytes under the influence of an influenza vaccine combined with a low molecular weight germanium organic compound].

AIM: Confirmation of immunostimulating effect of an original low molecular weight germanium organic compound (LMW-GOC) during immunization of mice with Vaxigrip vaccine. MATERIALS AND METHODS: The experiments were carried out in CBA mice divided into 4 groups: control, those that received Vaxigrip influenza vaccine intraperitoneally, those that received LMW-GOC intraperitoneally and those that received both preparations at once. Effect of the preparations administered was evaluated by flow cytofluorometry based on changes of CD3, CD4, CD5, CD8, CD19, CD25, Foxp3, NK1.1, gammadelta T, MHC II, TLR2, TLR4, TLR9 expressing cell content in mice spleens. The content of the colored cells was determined at normal, 24 hours and 7 days after the administration of the preparations. Statistical treatment of the data was carried out by using Win MD 128 program package. RESULTS: LMW-GOC can enhance the effect of Vaxigrip vaccine that is expressed by an increase of content in spleen of some lymphocyte subpopulations 24 hours and 7 days after the intraperitoneal administration. In some cases LMW-GOC increases the content of some lymphocyte subpopulations in mice spleen after administration as a monopreparation, i.e. without the vaccine. LMW-GOC suppressed stimulating effect of the vaccine on the spleen content of various lymphocyte subpopulations in none of the observations. CONCLUSION: By using cytofluorometry method it is possible to form an understanding of an elevated role of various types of cells in the development of immune response to the vaccine as well as regarding additional enhancement of this response during administration of LMW-GOC to mice. The effect of the preparation is manifested for a few days after its administration. The preparation manifests adjuvant properties and after further studies may be suggested for use as an adjuvant.

[Effect of methods of application of bacterial ligands on activation of lymphoid organs' effectors in mice].

AIM: Evaluation of differentiation dynamics and localization of various populations of lymphocytes as well as their expression of TLRs during different methods of administration (intranasal, oral, and subcutaneous) of bacterial ligands of opportunistic microorganisms (Immunovac-VP-4 vaccine) in experiment on mice. MATERIALS AND METHODS: Polycomponent vaccine Immunovac-VP-4 consisting of ligands of 4 opportunistic bacteria was administered to CBA line mice. Groups of mice were immunized orally, subcutaneously, or intranasally. Number of mononuclear leukocytes, as well as levels of cytokines, lymphocytic antigens, and cytotoxic activity of cells were measured. RESULTS: It was demonstrated that modification of immunophenotype of lymphocytes and cytotoxic activity of NK cells depends from route of administration of Immunovac-VP-4 because the most intensive activation of cells occurred in organs proximal to place of vaccine application. However, already 1 day after administration of vaccine there was intensive exchange between lymphoid cells not only in nasal associated lymphoid tissue, bronchial associated lymphoid tissue, and gut associated lymphoid tissue but also in spleen that points to integration of fine mechanisms of mucosal and systemic immune response regulation. CONCLUSION: Development of noninvasive methods of vaccination is an optimal way of safe and mass prevention of infectious diseases.

[Induction of dendritic cells maturation by staphylococcal antigens].

AIM: To study the ability to induce dendritic cells maturation obtained from bone marrow of mice by staphylococcal complex of antigens containing bacterial ligands for Toll-like receptors (lipopeptides, lipoproteins, and peptidoglycans). MATERIALS AND METHODS: Commercially available TNF-alpha, inductors ofdendritic cells (DCs) maturation, as well C57/BL line mice were used for the study. Immunophenotype of DCs was assessed by flow cytometry and monoclonal antibodies against cellular antigens. Cytological study using phase-contrast microscopy as well as electron microscopy were performed. Levels of cytokines were measured by ELISA. RESULTS: Obtained DCs had typical morphologic characteristics of mature cells. However the culture was still heterogenous with presence of macrophages that was evident from immunophenotype of obtained cells: CD34(-/+), CD38+, CD40+, CD80+, CD86+, MHC II+, F4/80(-/+). Number of TLR2-expressing cells was also reliably increased in culture of DCs that confirms the presence of corresponding ligands binding with this type of receptor in the preparation. Application of each studied preparation resulted in synthesis of large amount of TNF-alpha, IL-6, IL-1beta, IL-12 by DCs, and IFN-gamma by several types of them (RP and CB24). Although the intensity of induced cytokine synthesis varied for each preparation, it was many times higher compared with immature DCs. CONCLUSION: High synthesis level and wide spectrum of cytokine production demonstrated that under the influence of bacterial ligands DCs acquired characteristics needed for effective antigen presentation and priming of immune response.

[Expression of Toll-like receptors in spleen and lymphatic nodes after immunization by mucosal routes].

AIM: To determine level of Toll-like receptors (TLRs) expression in spleen and lymphatic nodes of mice after immunization by mucosal routes. MATERIALS AND METHODS: Mice were immunized with polycomponent vaccine Immunovac either by mucosal or subcutaneous route. Expression of TLRs in spleen, respiratory tract-associated lymphatic nodes as well as in small intestine was measured in immunized mice by flow cytomentry method. RESULTS: After immunization of mice by subcutaneous, intranasal and oral routes level of TLRs expression was different. Significant expression of TLR9 and absence of TLR2 expression was noted after non-parenteral methods of immunization. After oral immunization expression of TLRs was identified in gut-and respiratory tract-associated lymphoid tissue as well as in spleen; after intranasal immunization--in respiratory tract-associated lymphoid tissue, and after subcutaneous immunization--in spleen and respiratory tract-associated lymphoid tissue. CONCLUSION: After oral immunization expression of TLRs was identified in all studied organs, including spleen. Involvement of spleen to this process allows to assume establishment of not only local but also systemic immunity.