Oocyte donation pregnancies with high fetal-maternal immunogenetic dissimilarity show alterations in the maternal peripheral immunoregulatory response.

Oocyte donation (OD) pregnancies result in increased fetal-maternal immunogenetic dissimilarity due to paternal and donor-derived genes. Higher fetal-maternal HLA mismatches are correlated with preeclampsia. Therefore, this study explored the maternal immune response, focusing on regulatory T cells (Tregs) during low versus high allogeneic pregnancies, and healthy versus preeclamptic OD pregnancies.

Immune suppression by human thymus-derived effector Tregs relies on glucose/lactate-fueled fatty acid synthesis.

Regulatory T cells (Tregs) suppress pro-inflammatory conventional T cell (Tconv) responses. As lipids impact cell signaling and function, we compare the lipid composition of CD4 thymus-derived (t)Tregs and Tconvs. Lipidomics reveal constitutive enrichment of neutral lipids in Tconvs and phospholipids in tTregs.

Tregs from human blood differentiate into nonlymphoid tissue-resident effector cells upon TNFR2 costimulation.

Tregs can facilitate transplant tolerance and attenuate autoimmune and inflammatory diseases. Therefore, it is clinically relevant to stimulate Treg expansion and function in vivo and to create therapeutic Treg products in vitro. We report that TNF receptor 2 (TNFR2) is a unique costimulus for naive, thymus-derived Tregs (tTregs) from human blood that promotes their differentiation into nonlymphoid tissue-resident (NLT-resident) effector Tregs, without Th-like polarization.

Imaging mass cytometry reveals the prominent role of myeloid cells at the maternal-fetal interface.

Although the immunological complexity of the maternal-fetal interface is well appreciated, the actual interaction of maternal immune cells and fetal trophoblasts is insufficiently understood. To comprehend the composition and spatial orientation of maternal immune cells and fetal extravillous trophoblasts, we applied imaging mass cytometry on decidua basalis of the three trimesters of healthy pregnancy. Within all trimesters, we observed considerably higher frequencies of myeloid cells in the decidua than is seen with single-cell suspension techniques.

Frontline Science: Placenta-derived decidual stromal cells alter IL-2R expression and signaling in alloantigen-activated T cells.

This study investigated how stromal cells affect the IL-2 pathway in alloantigen-activated T cells. We found that decidual stromal cells (DSCs) from term placentas promoted a high production of IL-2 in cultures with alloantigen-activated T cells. The intensity of expression of cluster of differentiation 25 (CD25; IL-2Rα) on T cells was increased by DSCs, whereas the frequency and intensity of expression of the signaling subunits CD122 (IL-2Rβ) and CD132 (IL-2Rγ) were reduced.