Microparticles are microvesicles forming during cell activation and as a result of apoptotic cell death. Normal pregnancy is associated with apoptosis induction in active immune system cells, present in the decidual tissue. Preeclampsia is associated with activation of the peripheral blood leukocytes and more intense apoptosis of the trophoblast cells. As a result, the number of microparticles in the peripheral blood is changing in normal gestation and in preeclampsia. The content of the leukocytic microparticles in the peripheral blood is evaluated in normal pregnancy and preeclampsia. The content of neutrophilic and monocytic microparticles is higher than normally in preeclampsia, this indicating activation of these cells. The number of microparticles formed by NK cells is low in preeclampsia, which can reflect the incompetence of immunological tolerance mechanisms under these conditions.

Резюме. Микровезикулы (МВ)-субклеточные структуры размером от 100 до 1000 нм, продуцируемые клетками в состоянии покоя и активации. МВ могут передавать молекулы клеткам-мишеням, регулировать физиологические процессы, участвовать в патологиях. Микровезикулы лейкоцитарного происхождения, в частности МВ NK-клеток, остаются наименее изученной популяцией МВ. NK-клетки способны изменять функциональную активность эндотелиальных клеток (ЭК), участвуют в регуляции ангиогенеза. Недостаточно изучена способность МВ NK-клеток влиять на функциональное состояние ЭК. Целью настоящего исследования явилось изучение влияния МВ, образуемых естественными киллерами линии NK-92, на фенотип, активность каспаз, пролиферацию и миграцию ЭК линии EA.Hy926. ЭК культивировали в присутствии МВ клеток линии NK-92. При помощи проточной цитофлуориметрии оценивали изменение фенотипа ЭК, передачу внутриклеточного белка из МВ в ЭК, относительную гибель ЭК. При помощи Western blot analysis оценивали экспрессию гранзима B в NK-клетках и их МВ, появление гранзима B в ЭК, экспрессию каспаз, Erk, AKT в ЭК. Также оценивали пролиферацию и миграцию ЭК в присутствии МВ клеток линии NK-92. Установлено значимое различие протеомных профилей клеток линии NK-92 и образуемых ими МВ. Контакт ЭК с МВ клеток линии NK-92 сопровождается развитием следующих событий: 1) экспрессией в ЭК гранзима В; 2) активацией каспазы-9, каспазы-3 и частичной гибелью ЭК; 3) появлением на ЭК панлейкоцитарного маркера CD45; 4) снижением экспрессии CD105 и повышением экспрессии CD34 и CD54; 5) ингибированием миграции ЭК. Передача эндотелиальным клеткам Erk, но не AKT, в составе МВ клеток линии NK-92 в концентрации в 10 раз ниже концентрации, вызывающей гибель ЭК, способствует повышению пролиферации ЭК.

Despite ample data on cytokine secretion in the uteroplacental interface, the influence of microenvironment cells, in particular, trophoblast cells on angiogenesis and the role of cytokines in this process remain poorly studied. We studied the influence of cytokines on the formation of tube-like structures by endothelial cells in the presence of trophoblast cells and showed that trophoblast cells suppressed the angiogenic potential of endothelial cells. Antiangiogenic cytokines IFN-γ, IL-10, TNF-α, and TGFβ via modulation of trophoblast cells stimulated the formation of tube-like structures by endothelial cells. In the co-culture of endothelial and trophoblast cells, the effects of cytokines changed and they gained additional regulatory functions.

No abstract

Natural killer (NK) cells are of special interest among a multitude of microvesicle (MV) source cells. NK cells are a lymphocyte subpopulation performing contact cytolysis of virus-infected cells and tumor cells. Each of the NK cell populations has a unique receptor repertoire on its surface and, thus, unique functions. During their contact with a target cell, the most common mechanism of cytolysis is an exocytosis of lytic granules. However, some indirect evidence suggests that MV with CD56 phenotype and leukocyte-derived MV with various phenotypes are present in the peripheral blood plasma.This research is aimed to study the phenotype, composition and cytotoxic activity of microvesicles produced by NK cells. The analysis of receptor expression showed that MV, as well as source cells of the NK-92 cell line, had a similar CD56 molecule expression profile. The expression profile in MV differs from the same in source cells by higher CD119 and CD11b expression and by lower CD18 expression. Culturing of NK-92 cells in the presence of PMA, IL-1β, TNFα, IFNγ resulted in alterations of cell phenotypes and MV. Immunoblots revealed a change of perforin and granzyme B (GrB) in MV. The analysis of the cytotoxic activity of NK-92 cells in a natural killer in vitro assay employing K562 target cells demonstrated that MV obtained from TNFα-activated cells of the NK-92 cell line increased the cytotoxicity of the same TNFα-activated NK-92 cells regarding cytotoxicity levels. This coincides with the previously revealed increased content of GrB in MV obtained from TNFα-activated cells of the NK-92 cell line. To sum up depending on the cytokine NK-92 cells produce MV that differ in their phenotype, composition and activity. Any changes in MV composition can result in changes in their functional activity: in particular, changes can increase the cytotoxic activity of NK cells of the NK-92 cell line. Thus, besides a well-known and proved way for GrB delivery to a target cell, we can suggest an additional way – the transportation of GrB within MV.