Ex vivo expansion of cord blood haematopoietic stem/progenitor cells under physiological oxygen tensions: clear-cut effects on cell proliferation, differentiation and metabolism.

Physiologically low O(2) tensions are believed to regulate haematopoietic stem cell (HSC) functions in the bone marrow (BM; 0-5%). In turn, placenta and umbilical cord are characterized by slightly higher physiological O(2) tensions (3-10%). We hypothesized that O(2) concentrations within this range may be exploited to augment the ex vivo expansion/maintenance of HSCs from umbilical cord (placental) blood (UCB).

Tolerogenic versus inflammatory activity of peripheral blood monocytes and dendritic cells subpopulations in systemic lupus erythematosus.

Abnormalities in monocytes and in peripheral blood dendritic cells (DC) subsets have been reported in systemic lupus erythematosus (SLE). We aim to clarify the tolerogenic or inflammatory role of these cells based on ICOSL or IFN-α and chemokine mRNA expression, respectively, after cell purification. The study included 18 SLE patients with active disease (ASLE), 25 with inactive disease (ISLE), and 30 healthy controls (HG).

Phenotypic and functional alterations on inflammatory peripheral blood cells after acute myocardial infarction.

The frequency and function of T cells, monocytes, and dendritic cell subsets were investigated in 12 patients after acute myocardial infarction (AMI)-(T0), 1 month after the episode (T1), and in 12 healthy individuals (HG). The cell characterization and the functional studies were performed by flow cytometry and by RT-PCR, after cell sorting. The most important findings at T0 moment, when compared with T1 and HG, were: a decrease in the frequency of IL-2-producing T cells; a lower frequency of TNF-α- and IL-6-producing monocytes, myeloid dendritic cells, and CD14(-/low)CD16(+)DCs; and a lower TNF-α mRNA expression, after sorting these cells.

Influence of pro- and anti-inflammatory cytokines in Th1 polarization after allogeneic stimulation.

The exogenous cytokine milieu can influence Th1/Th2 polarization. Besides the differential functional properties, T lymphocytes also acquire distinct profiles of chemokine receptors. Human Th1 lymphocytes preferentially express CCR5 and CXCR3 while Th2 lymphocytes express CCR3, CCR4 and CCR8.

Immunophenotypic and functional characterization of cord blood dendritic cells.

Dendritic cells (DCs) play a pivotal role in the activation of T cells, which are effector cells in graft-versus-host disease (GVHD). A low incidence of GVHD following cord blood (CB) transplantation has long been reported; despite this, little information is currently available on the characteristics of CB DCs. The goal of the present study was to investigate the immunophenotypic characteristics and distribution of CB DCs and their subsets.