Effect of Activated Immunocompetent Cells on the Content of Multipotent Stromal Cells in Splenic Transplants of CBA and CBA/N Mice Administered with Polyvinylpyrrolidone.

One day after intraperitoneal injection of polyvinylpyrrolidone (PVP) to recipient CBA and CBA/N mice, the count of multipotent stromal cells (MSC) in the 4-month-old splenic transplants was minimum in CBA/N→CBA/N group in comparison with the transplants of intact recipients (0.6 from the control level), but increased by 2.3, 3.2, and 3.7 times in CBA/N→CBA, CBA→CBA, and CBA→CBA/N groups, respectively. In the blood serum of recipient CBA/N mice with 4-month splenic transplants of CBA donors, the levels of some cytokines (IL-5, TNFα, and IL-2) was significantly increased 1 and 24 h after PVP injection in contrast to mice with bone marrow transplants, which attests to activation of the innate immunity mechanisms in this (splenic) transplantation variant. Probably, this phenomenon can be explained by the fact that the splenic transplants contain a sufficient number of CD+B-1a lymphocytes that can restore the response of recipient CBA/N mice to PVP. Thus, similar to bone marrow transplants [5], MSC count in splenic transplants increased only in groups, where the recipients were capable of responding to PVP. In other words, after injection of PVP to recipient mice, MSC counts in the spleen and bone marrow at this moment are determined by availability of activated immunocompetent cells. Overall, the novel data attest to close relationships between the stromal tissue of hematopoietic and lymphoid organs, on the one hand, and immune system, on the other.

Simultaneous Administration of NOD-2 (MDP) and TLP-4 (LPS) Ligands to Bone Marrow Donors 24 h before Transplantation Increases the Content of Multipotent Stromal Cells (MSCs) in Bone Marrow Grafts in CBA Mice Compared to the Total Result of Their Isolated Administration.

In 3-month bone marrow transplants of CBA mice from bone marrow donors receiving single injections of TLR-4 ligand (LPS) or NOD-2 ligand (muramyl dipeptide, MDP) 24 h before transplantation, an increase in the total number of MSCs (by 2.6 and 1.9 times, respectively), as well as a slight increase in the number of nuclear cells and the mass of bone capsules (by 1.3 and 1.2 times) were observed. After combined administration of MDР and LPS to donors, the total content of MSCs in the grafts was higher by 1.6 times in comparison with the total result of their isolated administration (and by 7.2 times in comparison with the control). At the same time, the concentration of osteogenic MSCs in the grafts of all groups was almost the same and corresponded to the control level. The number of nuclear cells and the mass of bone capsules of the grafts after combined administration of LPS and MDP were close (~80%) to the sum of the results of their isolated administration. These findings suggest that activation of the stromal tissue and the success of bone marrow transplantation depend on the intensity of innate immune responses. These data can be useful for the development of optimal methods of tissue transplantation.

Effect of Activated Immunocompetent Cells on the Number of Multipotent Stromal Cells in Bone Marrow Transplants of CBA and CBA/N Mice in a Short Time after Polyvinylpyrrolidone Administration to Animals.

One hour after polyvinylpyrrolidone administration, the content of multipotent stromal cells in the spleen of CBA and CBA/N mice increased almost equally (by 2.5 and 2.9 times, respectively), but in 24 h, the effectiveness of multipotent stromal cell cloning in the spleen of CBA/N mice decreased almost to the control level, whereas in CBA mice, the number of multipotent stromal cells continued to increase. Serum concentration of IL-5, TNFα, and IL-2 in both lines was elevated in 1 h after polyvinylpyrrolidone administration, which is likely to reflect activation of the innate immunity. One day after polyvinylpyrrolidone administration, the number of multipotent stromal cells in bone marrow transplants in the CBA/N→CBA/N and CBA→CBA/N groups remained practically unchanged, while in groups CBA→CBA and CBA/N→CBA it was equally increased (by 3.6 and 3.4 times, respectively). Thus, the number of multipotent stromal cells in bone marrow transplants after 1 day was increased only in groups where recipients (CBA mice) were capable of responding to polyvinylpyrrolidone administration, i.e. the number of stromal cells by this term, was apparently determined by the presence of activated immunocompetent cells. These findings also indicate that activation of the stromal tissue dur ing immune response can have a two-phasic pattern: the first phase (1 h after antigen adminis tration) can be determined by activation of innate immunity receptors (in multipotent stromal cells or other cells) observed in CBA and CBA/N mice, and the second phase occurs during further development of the immune response (that was observed in CBA mice, but not in CBA/N mice due to absence of CD+B-1a lymphocytes). The findings attest to close interactions between the stromal tissue and the immune system.

Local and Systemic Functional Responses of Mouse Macrophages to Intravaginal Infection with Type 2 Herpes Simplex Virus and Vaccination.

Activity of cathepsin D and phagocytosis of macrophages from vaginal lavage fluid, peritoneal exudation, and spleen were studied in mice of sensitive (DBA/2) and resistant (BALB/c) lines after intravaginal infection with type 2 herpes simplex virus and vaccination. Activity of cathepsin D and intensity of phagocytosis (irrespective of the macrophage source) and their ratio in BALB/c mice in early terms after infection were close to the control levels taken as a unit. In DBA/2 mice, these parameters and their balance were shifted and changes in cathepsin D activity depended on the time after challenge. Activities of cellular and extracellular cathepsin D increased sharply on day 1 postinfection under conditions of local virus interaction with the vaginal mucosa and activation of the pathological process. Later, after generalization of the infection, activity of cathepsin D decreased, while phagocytosis increased in all the studied macrophage populations. Vaccination corrected the cathepsin D/phagocytosis imbalance and created conditions for rapid elimination of the virus.

[PNEUMOCOCCAL BIOFILMS AS A FORM OF PERSISTENCE: FORMATION, STRUCTURE, ROLE IN PATHOGENESIS, IMMUNE RESPONSE].

A review of studies on pneumococcal biofilms as a form of persistence is presented. The following provisions are examined: formation of pneumococcal biofilm on abiotic and mucosal surfaces, pathogenetic significance of biofilm pneumococci, their immunogenicity, as well as resistance to antibiotics and unfavorable environmental factors. Differences between biofilm properties, that are formed in vivo and in vitro, are shown. The significance of pneumococcal biofilm formation as means of survival for a long time is underscored.

[Pneumococcus pathogenicity factors and their protective properties].

Owing to rapid development of molecular-biological and genetic methods of research in infectology as well as use of adequate models (tissue colonization of human respiratory epithelium, mice models of colonization, sepsis and meningitis), a significant progress in the field of pneumococcus pathogenicity factors has been made in the last decades. Aside from the well-known pathogenicity factor--capsule polysaccharide, to date several dozens of surface proteins providing adhesion, colonization and invasion have been detected in pneumococcus. Pneumolysin is a toxic factor and at the same time brain invasion factor. Many of the known pathogenicity factors play a role in formation of biofilm that facilitates prolonged colonization of nasopharynx. Protective activity has been proved for some of the surface proteins and pneumolysin that forms the base for development of novel rational pneumococcal vaccines as an alternative to polysaccharide.

[Dual role of photosensibilizator merocyanine 540 as a bactericidal agent and immune reaction regulator].

AIM: Develop conditions for inactivation of staphylococcus by using photosensibilizator merocyanine 540 (MC540) for the production of antigenic preparation (AP). Study some of immune reactions to AP and the possibility of regulation of DTH reaction to AP under the effect of MC540. MATERIALS AND METHODS: Merocyanine 540 (MC540, Sigma-Aldrich, Switzerland) is used in the study. MC540 and Staphylococcus aureus, strain 78 (Sa78) were irradiated by light of a mercury-quartz lamp DRSH-250 (Zelenograd). C56BL/6 line mice were immunized once by subcutaneous administration of AP. DTH reaction was tested 7 days after the immunization. Functional activity of peritoneal exudate macrophages was determined 1 and 9 days after the immunization. Immune modulating effect of MC540 in DTH was determined after its per os administration to mice 1 hour after AP sensibilization. RESULTS: In order to obtain AP, S. aureus suspension at the concentration of 2.5 x 10(7) CFU/ml in 25 microM MC540 solution and 0.25 M NaCl solution were exposed to irradiation for 5 minutes. During DTH reaction induction its intensity dependence on AP dose was revealed. A persistent increase of a lysosomatic enzyme cathepsin D in macrophages of peritoneal exudate after a single administration of AP was noted. During MC540 irradiation an accumulation of photoproducts that have a pronounced immune suppression effect in DTH reaction had a dose-dependent character. CONCLUSION: Use of saline allows to increase bactericidal potential of a photosensibilizator (PS). However during therapy of localized forms of infection a possible immune modulating effect of PS on macro organism should be considered. By varying PS dose and irradiation time not only maximum bactericidal effect can be achieved but also regulation of inflammatory reactions in the area of PS effect can be ensured.

Effect of Sodium Chloride on Aggregation of Merocyanine 540 and Photosensitized Inactivation of Staphylococcus aureus and Pseudomonas aeruginosa.

Merocyanine 540 (MC540) is used as a photosensitizer for the inactivation of microorganisms. The following is already known about MC540: firstly, MC540 exists in distilled water in both monomeric and dimeric forms, and the addition of salts into a MC540 solution leads to the formation of large aggregates that can be detected by the resonance light scattering technique. Secondly, singlet oxygen can only be photogenerated by MC540 monomers. In the present work, we studied the effect of MC540 in the aggregated state on the rate of photosensitized inactivation ofStaphylococcus aureusandPseudomonas aeruginosa. To this end, bacteria either in MC540-containing distilled water or in a 0.25 M sodium chloride aqueous solution also containing MC540 are irradiated (546 nm). The results show that, in the presence of salt, the aggregation of MC540 greatly increases the efficiency of the MC540-photosensitized inactivation ofP. aeruginosaandS. aureus. In the presence of salt, the rates ofP. aeruginosaandS. aureusinactivation increase by factors of 10 and 30, respectively, in comparison with the rate of inactivation observed in the case of distilled water. Our results suggest that a salt-induced photosensitization mechanism can switch from the singlet oxygen to the free-radical pathway.

[Immunobiological features of bacterial cells of medical biofilms].

Biofilm is a integrated multucellular organism with own cycle of development, cooperative behavior of units forming it, which coordinated by QS-system based on production of signal molecules or autoinductors and ability of bacteria to receive these signals. Presence ofbacteria attached to surface of biomedical devices and formation of bacterial biofilms in the microorganism could lead to chronic inflammation, which characterized by presence of macrophages and lymphocytes in the focus of inflammation as well as proliferation of connective tissue, accumulation of matrix proteins and stimulation ofangiogenesis. Process of biofilm formation associated with activation of QS-system of different agents including potentially dangerous bacteria plays certain role in exacerbation of gastric and duodenal ulcer diseases, Crohn's disease, myocarditis, asthma, diabetes mellitus, cardiovascular and other somatic diseases. Detachment of biofilm could lead to enter ofbac-teria in bloodsream and vascular embolism. Issues related to ability of bacteria of biofilms to modulate immune response and potential for the emerging response to influence the biofilm growth and level of expression of bacterial virulence are discussed. Modem views on mechanisms of interaction of bacteria of exopolysaccharide biofilm with host's immune response factors are reviewed. The most perspective ways to control for biofilm formation and their disruption using newly developing drugs are outlined.

[Bacterial carriage as a form of persistence of meningococci].

Features of meningococcal carriage as a form of microorganism's persistence necessary for survival and species preservation are discussed in this review. New data on genetic heterogeneity of meningococcal population, which is major determinant of occurrence-of asymptomatic forms, are presented. Process of formation of meningococcal biofilms is described. Materials about systemic and local immunity developed during meningococcal carriage and possible influence of vaccination on carriage rate are reviewed. Role of persistence of meningococci in stimulation of immune protection of population from severe forms is discussed.

[Epidemic process of gonorrhea in modern world].

Gonorrhea in spite of its fully elucidated etiopathogenesis and available drugs for etiotropic therapy belongs to infections which are not controlled by vaccination due to absence of immunity formation. Analysis of scientific publication, statistical materials and WHO's data showed that epidemic process of gonorrhea infection depends mainly from people's behaviour, first of all, sexual. Modern epidemic process of gonorrhea infection consists from irregular increases and decreases of incidence due to various reasons. Reasons for increases of incidence appear to be simultaneous action of a range of biologic and anthropogenic factors. First reason--rapid increase of resistance of gonococci to widely used antibacterial preparations as well as synergy of pathogenic effects between HIV and gonococci; anthropogenic--wars, increase of high-risk groups due to urbanization, use of oral contraceptives, rise of prostitution, migration, inadequate access to medical care, poverty, intensification of intercourses (including hetero- and homosexual) between people, as well as demographic changes--increase of proportion of young people in population structure. Same but reciprocal factors lead to decrease of morbidity. Of them, the following were considered as most important: mass implementation of new effective antimicrobial drug as well as intensification of sanitary education, availability of early diagnostics and treatment, increase of material and cultural standards of life, decrease in number of persons belonging to high risk groups. Yet, capabilities of modern science expressed only in continuous development of new antibacterial drugs active against circulating population of gonococci, which is resistant to previously used drug.

[Mechanisms of Chlamydia trachomatis and herpes simplex virus persistence during viral-bacterial infection].

Possible mechanisms of persistence on the example of Chlamydia trachomatis in conditions of herpes simplex virus type 2 (HSV-2) superinfection in vitro and in vivo are described. Emergence of persisting forms of Chlamydia as well as factors influencing on this process are considered. Contemporary views on pathogenesis of viral-bacterial infection with HSV-2 and C. trachomatis as well as interactions of the agents with local immunity factors are described. It was suggested that there are signaling pathways through which HSV-2 changes life cycle of Chlamydia.

[Molecular biological basis of the gonococcal pathogenicity and specific features of immune response].

The pathogenicity factors of gonococci--pili, outer membrane proteins (porins, Opa proteins, iron-regulated proteins), lipooligosaccharide, a number of secreted enzymes--are considered according to our knowledge of their relationships with different human specialized cells, including neutrophils. The main stages of the infectious process of gonorrhea are described in the light of modern concept of "parasite-host" relationships. Materials on the instability of gonococcal antigens, and frequent formation of new antigenic variants are presented. This is the main cause of the absence of postinfectious immunity in gonorrhea and the limitation of possibility for creating effective vaccine in the near future.

[The correction action of Phosprenyl and Gamavit on the functional activity of mouse peritoneal macrophages in response to high doses of Staphylococcus aureus alpha-toxin].

The study of the functional activity of peritoneal macrophages of BALB/c mice at different stages of the toxic action caused by S. aureus alpha-toxin (ST) was carried out. The analysis of the dynamics of toxic reaction revealed the main critical points of triggering necrotic processes: the first hour and day 2. One hour after the injection of large doses of ST a sharp increase in the process of antigen binding with its subsequent sharp decrease. Simultaneously, a decrease in the activity of the lysosomal enzymes cathepsin D and acidic phosphatase was established, which was indicative of the destabilization of both lysosomal and cellular macrophage membranes. The increase of oxygen metabolism on day 2, together with the release of lysosomal proteases into the extracellular area, correlated with the maximum death rate of mice and served as the main index of the development of necrosis. The prophylactic and therapeutic use of the preparations Gamavit and Phosprenyl revealed their antitoxic activity and capacityfor stimulating the level of natural body resistance.

Comparative study of macrophage response in mice after DNA immunization and infection with herpes simplex virus type 1.

Functional activity of macrophages and intensity of T cell immune response in mice were studied after intravaginal and intraperitoneal infection with herpes simplex virus type 1 and DNA vaccination in combination with adjuvant treatment (recombinant granulocyte-macrophage colony-stimulating factor and glucosaminylmuramyl dipeptide). DNA vaccination induced a virus-specific T cell immune response with no macrophagic inflammatory reaction. Infection with herpes simplex virus type 1 was accompanied by sustained inflammation, but not by the T cell immune response.

The Attenuation of Effectors and Induction of Suppressors of Delayed Type Hypersensitivity Reaction under the Treatment with Psoralen Photooxidation Products.

Psoralens, together with ultraviolet light A (PUVA), are used for the treatment of the series of T cell mediated diseases. The role of photooxidative reactions in psoralen phototherapy is not entirely clear. Using model of delayed type hypersensitivity (DTH) reaction to sheep red blood cells and evaluating the antibody production in mice, we investigated the influence of produced in vitro psoralen photooxidation products (POP) on the functions of T and B effectors. The research showed POP to induce inhibition of the DTH reaction independently on the phase of immune response it was injected. It was revealed that in vitro POP treatment of splenocytes, containing mature effectors, partially impaired their capacity to transfer the DTH reaction. The POP effect was not related to the direct cytolysis. In vivo POP injection to sensitized mice-donors resulted in much stronger alteration of DTH effectors than in the case of in vitro POP treatment. We elaborated the model for evaluation of functional activity of DTH suppressors. Using the model, we found that, being intravenously injected, POP induced DTH suppressors other then T cells. Furthermore, it was shown that intravenously injected POP did not affect antibody production. Thus, the POP selectively influenced T cells and had no effect on B cells. Probably, psoralen photooxidation products may be used for the therapy of some hyperproliferative T cell mediated diseases.

Products of psoralen photooxidation possess immunomodulative and antileukemic effects.

It has been proposed that the therapeutic effect of PUVA (psoralens+UVA radiation) is connected to its immunomodulative properties, and that the molecular basis of such properties is the oxygen-independent photoaddition of psoralens to DNA. We have investigated effects of preliminary photooxidized psoralens (POP) on the delayed-type hypersensitivity reaction (DTH) to sheep red blood cells and on growth of grafted T-cell lymphoma EL-4 in mice. We have shown that intravenous injection of POP at low concentrations activated, and at high concentrations suppressed, DTH. The POP products are thermolabile. They preserved their immunosuppressive activity for 3 days at room temperature and lost it in several min at 58 degrees C. Incubation of POP in the presence of Fe2+ during 2 h before intravenous injection leads to complete loss of its immunomodulative activity, suggesting a peroxidic nature of POP products. The POP-inhibited growth of grafted T-cell lymphoma independent of the mode of POP application in mice (intravenous or subcutaneous injections, oral or nasal administration). Our data suggest that photooxidative reactions of psoralens, in addition to oxygen-independent photoaddition to DNA, form the basis for biological activity of these drugs.

[Suppression of delayed hypersensitivity to microbial and transplantation antigens with ultraviolet radiation]. / Podavlenie UF-oblucheniem giperchuvstvitel'nosti zamedlennogo tipa k mikrobnym i transplantatsionnym antigenam.

The influence of ultraviolet (UV) radiation on delayed hypersensitivity to antigens of different nature has been studied. UV radiation in different doses has been shown to induce the suppression of delayed hypersensitivity to staphylococcal cell-wall antigens and transplantation alloantigens.