Human decidual macrophages and NK cells differentially express Toll-like receptors and display distinct cytokine profiles upon TLR stimulation.

Maternofetal pathogen transmission is partially controlled at the level of the maternal uterine mucosa at the fetal implantation site (the decidua basalis), where maternal and fetal cells are in close contact. Toll-like receptors (TLRs) may play an important role in initiating rapid immune responses against pathogens in the decidua basalis, however the tolerant microenvironment should be preserved in order to allow fetal development. Here we investigated the expression and functionality of TLRs expressed by decidual macrophages (dMs) and NK cells (dNKs), the major decidual immune cell populations.

Dynamic shift from CD85j/ILT-2 to NKG2D NK receptor expression pattern on human decidual NK during the first trimester of pregnancy.

During the first trimester of human pregnancy, Natural Killer (NK) cells of the maternal uterine mucosa (e.g. decidua) have a unique phenotype and are involved in crucial physiological processes during pregnancy.

Antigen-presenting cells represent targets for R5 HIV-1 infection in the first trimester pregnancy uterine mucosa.

Background: During the first trimester of pregnancy, HIV-1 mother-to-child transmission is relatively rare despite the permissivity of placental cells to cell-to-cell HIV-1 infection. The placenta interacts directly with maternal uterine cells (decidual cells) but the physiological role of the decidua in the control of HIV-1 transmission and whether decidua could be a source of infected cells is unknown.

Methodology/principal Findings: To answer to this question, decidual mononuclear cells were exposed to HIV-1 in vitro.