Elevated levels of dehydroepiandrosterone as a potential mechanism of dendritic cell impairment during pregnancy.

Background: This study aimed to test the hypothesis that immune dysfunction and the increased risk of spontaneous abortion in pregnant women with hyperandrogenia (HA) are caused by the reduced tolerogenic potential of dendritic cells (DCs) that results from elevated levels of dehydroepiandrosterone sulfate (DHEAS).

Methods: The phenotypic and functional properties of monocyte-derived DCs generated from blood monocytes from non-pregnant women, women with a normal pregnancy, or pregnant women with HA, as well as the in vitro effects of DHEAS on DCs in healthy pregnant women were investigated.

Results: In a normal pregnancy, DCs were shown to be immature and are characterized by a reduced number of CD83(+) and CD25(+) DCs, the ability to stimulate type 2 T cell responses and to induce T cell apoptosis.

Peripheral T Cell Apoptosis and Its Role in Generalized Bacterial Infections: A Minireview.

In the present review we have attempted to analyze recent findings concerning apoptosis of mature peripheral T cells. The great attention is made to the factors underlying resistance or sensitivity of mature T lymphocytes to activation-induced cell death. The role of preactivation and altered costimulation is discussed in this regard.

T Cell Functional Disturbances in Patients with Pulmonary Tuberculosis.

The investigations of 38 patients with pulmonary tuberculosis (PT) revealed combined T cell and monocyte functional disturbances. Indeed, the percentages of CD4(+) and CD8(+) T lymphocytes, proliferative response and IL-2 production, as well as the percentages of HLA DR(+) monocytes and IL-1beta production were significantly decreased in PT patients as compared with normal individuals. Herewith the absolute T lymphocyte number did not undergo the pronounced changes.