20 research outputs found
Interleukin-17-producing decidual CD4+ T cells are not deleterious for human pregnancy when they also produce interleukin-4
Get PDFBACKGROUND:
Trophoblast expressing paternal HLA-C antigens resemble a semiallograft, and could be rejected by maternal CD4+ T lymphocytes. We examined the possible role in human pregnancy of Th17 cells, known to be involved in allograft rejection and reported for this reason to be responsible for miscarriages. We also studied Th17/Th1 and Th17/Th2 cells never investigated before. We defined for the first time the role of different Th17 subpopulations at the embryo implantation site and the role of HLA-G5, produced by the trophoblast/embryo, on Th17 cell differentiation.
METHODS:
Cytokine production by CD4+ purified T cell and T clones from decidua of normal pregnancy, unexplained recurrent abortion, and ectopic pregnancy at both embryo implantation site and distant from that site were analyzed for protein and mRNA production. Antigen-specific T cell lines were derived in the presence and in the absence of HLA-G5.
RESULTS:
We found an associated spontaneous production of IL-17A, IL-17F and IL-4 along with expression of CD161, CCR8 and CCR4 (Th2- and Th17-type markers) in fresh decidua CD4+ T cells during successful pregnancy. There was a prevalence of Th17/Th2 cells (producing IL-17A, IL-17F, IL-22 and IL-4) in the decidua of successful pregnancy, but the exclusive presence of Th17 (producing IL-17A, IL-17F, IL-22) and Th17/Th1 (producing IL-17A, IL-17F, IL-22 and IFN-Îł) cells was found in the decidua of unexplained recurrent abortion. More importantly, we observed that Th17/Th2 cells were exclusively present at the embryo implantation site during tubal ectopic pregnancy, and that IL-4, GATA-3, IL-17A, ROR-C mRNA levels increased in tubal biopsies taken from embryo implantation sites, whereas Th17, Th17/Th1 and Th1 cells are exclusively present apart from implantation sites. Moreover, soluble HLA-G5 mediates the development of Th17/Th2 cells by increasing IL-4, IL-17A and IL-17F protein and mRNA production of CD4+ T helper cells.
CONCLUSION:
No pathogenic role of decidual Th17 cells during pregnancy was observed. Indeed, a beneficial role for these cells was observed when they also produced IL-4. HLA-G5 could be the key feature of the uterine microenvironment responsible for the development of Th17/Th2 cells, which seem to be crucial for successful embryo implantatio
What epigenetics can bring to (plant) physiologists and ecologists in a climate change context
No full textNational audienceRising temperatures and decreasing precipitations in relation to climate change are causing intense drought episodes and forest decline. Sessile and perennial organisms as trees must adapt to survive thanks to two biological processes: individual phenotypic plasticity and adaptation, the genetic evolutionary capacity of a population. Moreover, after experiencing stress, plants have the remarkable ability to retain an ecological memory of that event. They exploit this stress memory to manage their phenotypic plasticity, to improve their resistance, resilience and recovery, to finally increase chances of survival when they encounter similar conditions again.Recent studies showed that all differents mechanisms involved an epigenetic component in trees. However, little is known about the effects of recurring drought-rewatering stress cycles in trees and notably the epigenetic memory and potential priming effects. Such research was conducted in the frame of the ANR EPITREE project, which aims at studying the impact of DNA methylation, gene expression and allelic variations in the adaptation mechanisms of trees to their environment. Here, we tested for an ecological memory effect in genotypes from European natural populations of black poplars (Populus nigra). An experimental setup was designed to evaluate the tree's recovery, after a drought-rewatering cycle of five weeks of drought and one week of re-watering. The response was evaluated one week (short-time) after recovery to a first stress cycle and one week after a second stress cycle done a one year (inter-annual) after the first one. Phenotypic measurement as well as multi-omics characterizations (transcriptome and methylome) were performed on cambium, the meristematic tissue forming the conductive vessels and enabling the production of wood. Our results support a short-time as well as an interannual memory related to epigenetic variation, in black poplar subjected to drought stress cycles
What epigenetics can bring to (plant) physiologists and ecologists in a climate change context
No full textNational audienceRising temperatures and decreasing precipitations in relation to climate change are causing intense drought episodes and forest decline. Sessile and perennial organisms as trees must adapt to survive thanks to two biological processes: individual phenotypic plasticity and adaptation, the genetic evolutionary capacity of a population. Moreover, after experiencing stress, plants have the remarkable ability to retain an ecological memory of that event. They exploit this stress memory to manage their phenotypic plasticity, to improve their resistance, resilience and recovery, to finally increase chances of survival when they encounter similar conditions again.Recent studies showed that all differents mechanisms involved an epigenetic component in trees. However, little is known about the effects of recurring drought-rewatering stress cycles in trees and notably the epigenetic memory and potential priming effects. Such research was conducted in the frame of the ANR EPITREE project, which aims at studying the impact of DNA methylation, gene expression and allelic variations in the adaptation mechanisms of trees to their environment. Here, we tested for an ecological memory effect in genotypes from European natural populations of black poplars (Populus nigra). An experimental setup was designed to evaluate the tree's recovery, after a drought-rewatering cycle of five weeks of drought and one week of re-watering. The response was evaluated one week (short-time) after recovery to a first stress cycle and one week after a second stress cycle done a one year (inter-annual) after the first one. Phenotypic measurement as well as multi-omics characterizations (transcriptome and methylome) were performed on cambium, the meristematic tissue forming the conductive vessels and enabling the production of wood. Our results support a short-time as well as an interannual memory related to epigenetic variation, in black poplar subjected to drought stress cycles
