Diversity of dendritic cells generated from umbilical cord or adult peripheral blood precursors.

Following the discovery of methods to generate large numbers of specific dendritic cells (DCs) ex vivo, the possibility of exploiting these cells in immunotherapeutic strategies will become a reality. It seems to be rationally to analyse the influence of the precursor source for further features and applications. For the needs of the given project DCs were derived from precursors derived from adult peripheral blood (APB) and umbilical cord blood (UCB). During some expansions of UCB CD34+ cells were separated giving non-adherent DCs (NA-DCs) or adherent DCs (A-DCs), whereas DCs derived from UCB precursors without separation gave rise to All-DCs. DC subpopulations were stimulated by lipopolysaccharides (LPS) or interferon-γ (IFN-γ), and afterwards the morphology, phenotype, and stimulatory properties were analysed. Our findings demonstrated that DCs generated from APB and UCB precursors were not equivalent and exhibited opposite features when expanded in comparable conditions. Additionally, all three subpopulations of UCB-derived DCs presented functional dissimilarities. Based on our results we concluded that the precursor source and the composition of media must be considered as crucial to the success of potential therapeutic application.

Cytokine profiles during delivery affect cord blood hematopoietic stem and progenitors cells.

The study was aimed to determine the correlations between serum levels of cytokines (GM-CSF, IL-4, IL-10 and TNF) in maternal (MB) and cord blood (CB) and some features of cord blood hematopoietic stem and progenitor cells (CB HSPCs). Study material was MB and concomitant CB samples collected from 98 volunteers at the moment of delivery. The IL-4, IL-10, TNF and GM-CSF concentrations in serum and in supernatants from PMA-stimulated mononuclear cells isolated from both blood types were measured using BD Cytometric Bead Array Flex Set System. CB HSPCs (CD34(+)CD45(low)) proportion was also estimated by flow cytometry. The most relevant results concerned the tendency to down regulation of CB HSPCs number with an increase of IL-4, IL-10 and GM-CSF levels, only the TNF concentration seems to have no influence on HSPCs pole size. The strongest positive correlations were found between CD34(+)CD45(low) HSPCs number and IL-10 and GM-CSF in MB serum and GM-CSF and TNF from CB supernatants. The strongest negative correlations were found between CD34(+)CD45(low) HSPCs number and IL-4 and GM-CSF in CB serum and IL-10 in MB supernatants. Interestingly, we observed 'opposite correlation' between serum and supernatant from CB and MB. We concluded that elevated serum levels of IL-4, IL-10 and GM-CSF in CB are indicative of enhanced differentiation of HSPCs and characterize a normal perinatal development. Elevated levels of cytokines seem to stimulate differentiation of HSPCs what is advantageous for neonates during perinatal period.

A Proposed Molecular Mechanism of High-Dose Vitamin D3 Supplementation in Prevention and Treatment of Preeclampsia.

A randomized prospective clinical study performed on a group of 74 pregnant women (43 presenting with severe preeclampsia) proved that urinary levels of 15-F(2t)-isoprostane were significantly higher in preeclamptic patients relative to the control (3.05 vs. 2.00 ng/mg creatinine). Surprisingly enough, plasma levels of 25-hydroxyvitamin D3 in both study groups were below the clinical reference range with no significant difference between the groups. In vitro study performed on isolated placental mitochondria and placental cell line showed that suicidal self-oxidation of cytochrome P450scc may lead to structural disintegration of heme, potentially contributing to enhancement of oxidative stress phenomena in the course of preeclampsia. As placental cytochrome P450scc pleiotropic activity is implicated in the metabolism of free radical mediated arachidonic acid derivatives as well as multiple Vitamin D3 hydroxylations and progesterone synthesis, we propose that Vitamin D3 might act as a competitive inhibitor of placental cytochrome P450scc preventing the production of lipid peroxides or excess progesterone synthesis, both of which may contribute to the etiopathogenesis of preeclampsia. The proposed molecular mechanism is in accord with the preliminary clinical observations on the surprisingly high efficacy of high-dose Vitamin D3 supplementation in prevention and treatment of preeclampsia.