No abstract

Взаимодействие дендритных клеток с микроорганизмами, способными заселять кишечникФедеральное бюджетное учреждение науки «Нижегородский научно-исследовательский институт эпидемиологии и микробиологии им. академика И.Н. Блохиной» Федеральной службы по надзору в сфере защиты прав потребителей и благополучия человека, 603950, г. Нижний Новгород, Российская Федерация Резюме Введение. Один из возможных способов доставки вакцинных антигенов в слизистые оболочки для индукции мукозального иммунитета -использование бактериальных векторов. По нашему мнению, пригодные для этой цели микроорганизмы должны вызывать безопасную и, желательно, временную колонизацию слизистых, а также эффективно индуцировать иммунные реакции, в частности хорошо поглощаться антиген-презентирующими клетками и вызывать их созревание.Цель исследования -поиск микроорганизмов, пригодных для использования в качестве векторов для живых пероральных вакцин.Материал и методы. Использовали 8 различных бактерий и дрожжей, способных к постоянной или временной персистенции в желудочно-кишечном тракте. Сравнивали фагоцитоз микроорганизмов моноцитарными дендритными клетками человека, а также действие этих микроорганизмов на экспрессию дендритными клетками молекул CD83, CD86, CCR7 и CXCR5.Результаты. Подверженность фагоцитозу и способность индуцировать созревание дендритных клеток -независимые свойства микроорганизмов. Так, Escherichia coli относительно слабо фагоцитируется и приносит внутрь дендритных клеток мало микробного материала, но является сильным индуктором фенотипического созревания дендритных клеток. Lactiplantibacillus plantarum и Limosilactobacillus fermentum, напротив, хорошо поглощаются дендритными клетками, но слабо индуцируют их созревание.Заключение. На основании показателей фагоцитоза и способности стимулировать созревание дендритных клеток наиболее приемлемым кандидатом на роль бактериального вектора среди использованных в работе микроорганизмов представляется Bacillus cereus.

We previously found that the number of CCR6 + T-helpers with the phenotype of effector/effector memory T cells increases in the blood of patients with H. pylori -associated peptic ulcer. The mature phenotype and the expression of the chemokine receptor CCR6, which is involved in migration of lymphocytes to the inflamed mucous membrane of the gastrointestinal tract, suggests that these cells are involved in the immune response observed in this clinical condition. To better understand the pathogenetic role of these cells, it is necessary to study their functional activity, specifically, the production of pro-inflammatory cytokines involved in the pathogenesis of the disease. The aim of the study was to evaluate changes in the blood level of pro-inflammatory types of mature CCR6 + T-helpers in H. pylori -associated peptic ulcer disease. Materials and Methods. CCR6 + T-helpers were isolated from the blood by using immuno-magnetic separation adapted to this study. The number of T-helpers of types 1 and 17 (Th1 and Th17) and cells with mixed properties of Th1 and Th17 (Th1/Th17) was determined by intracellular cytokine assay. Results. Initially, we planned to activate unseparated peripheral blood mononuclear cells ex vivo and evaluate the number of cytokine producers among mature CCR6 + T-helper cells by gating them during the flow cytometry. However, dramatic changes in the phenotype of T-helpers upon activation did not allow us to reliably identify the cells of interest . Subsequently, we used a two-stage immunomagnetic separation procedure to obtain functionally active mature CCR6 + T-helpers with a purity of >90%. The quantitative yield of these cells from the blood of patients with gastric and duodenal peptic ulcer associated with H. pylori was 9 times higher than that from the blood of healthy donors. Activation of CCR6 + T-helpers purified from blood of ulcer patients revealed an increased content of Th1, Th17, and Th1/Th17. One ml of the patient’s blood yielded 18.1 times more CCR6 + Th1, 19.4 times more CCR6 + Th17, and 21.1 times more CCR6 + Th1/Th17 compared with the blood of healthy subjects. Conclusion. The content of mature CCR6 + T-helper cells with pro-inflammatory activity significantly increases in the blood of patients with peptic ulcer associated with H. pylori infection.

Introduction: Vaccines are one of the most effective means of preventing infectious diseases. Their effectiveness and safety are guaranteed by studies of vaccine properties, during their development and during the mandatory preclinical and clinical trials of each new vaccine. Additional information on the mechanisms of vaccine action on human immune system cells can be obtained using in vitro immune response models. The objective of the study was to determine applicability of certain methods of studying human dendritic cells in vitro to assessing the effect of vaccines. Dendritic cells are the most active antigen presenting cells, which play a key role in triggering a primary immune response to an infection or vaccine. Materials and methods: We studied the effect of vaccines on the maturation of dendritic cells, their phagocytic activity and the ability to stimulate T-lymphocytes in vitro. Results: To test the methods, we used vaccines with a known pattern of action on the immune system. All the vaccines induced the expression of dendritic cell maturation markers. At the same time, different vaccines induced a different set of markers and the degree of expression of these molecules. Quantitative methods for assessing phagocytosis and stimulating activity of dendritic cells are described. Conclusion: Methods for evaluation of phagocytosis, phenotypic maturation and functional properties of dendritic cells have been shown to be useful for evaluation of vaccine action. In our opinion, these methods, as a complement to traditional methods for evaluating the immune response, can be used to investigate the action of prototype vaccines at the stage of their development and preclinical trials.

and Pozharsky Square, Nizhny Novgorod, 603005, Russian Federation Dendritic cells (DC) are specialized antigen-presenting cells. One of their function is to deliver antigens from peripheral tissues to lymphoid organs by migration controlled by chemokines.The aim of the investigation was to study the effect of vaccines stimulating cellular or humoral response on the expression of chemokine receptors CCR7, CXCR4 and CXCR5 on DC, and assess the motility of the cells and migration response on chemokines.Materials and Methods. Immature DC derived from monocytes in vitro were incubated with vaccines. We used tuberculosis vaccine BCG stimulating, primarily, cellular response in vivo; hepatitis B vaccine stimulating antibody production, as well as aluminium hydroxide adjuvant. Reference DC maturation was induced with a cocktail of inflammatory mediators. Then, we assessed DC maturation and studied CCR7 gene expression, the presence of CCR7, CXCR4 and CXCR5 receptors on the outer membrane, spontaneous cell motility and chemotaxis induced by chemokines CCL21 and CXCL13.Results. BCG effectively induces DC maturation, has no effect on the expression of receptors CXCR4 and CXCR5 and causes slight but reliable enhanced expression of gene and receptor CCR7 as well as CCL21 induced chemotaxis. Hepatitis B vaccine causes partial DC maturation and increases significantly the expression of receptors CCR7, CXCR4 and CXCR5, but does not increase spontaneous cell motility and enhances weakly chemotaxis in response to CCL21 and CXCL13.Conclusion. Tuberculosis vaccine and hepatitis B vaccine induce different sets of chemokine receptors on DC, however, they stimulate DC hemotaxis relatively weakly. The findings suggest the necessity of searching new adjuvants, which enable to enhance the migration of DC carrying antigens to lymphoid organs.