Interleukin-17-producing decidual XXXX + T cells are not deleterious for @entity1 pregnancy when they also produce @entity3646 .

@entity1 @entity404 @entity21319 @entity9388 @entity13236 @entity9908 @entity1198 @entity4155 @entity7992 @entity16952 @entity4654 @entity379 @entity9235 @entity3646
BACKGROUND: Trophoblast expressing paternal HLA-C antigens resemble a semiallograft, and could be rejected by maternal @entity404 + T lymphocytes. We examined the possible role in @entity1 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/ @entity1198 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 @entity404 + purified T cell and T clones from decidua of normal pregnancy, @entity7992 , 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 @entity4155 , @entity4654 and @entity3646 along with expression of @entity21319 , @entity9235 and @entity16952 (Th2- and Th17-type markers) in fresh decidua @entity404 + T cells during successful pregnancy. There was a prevalence of Th17/Th2 cells (producing @entity4155 , @entity4654 , @entity13236 and @entity3646 ) in the decidua of successful pregnancy, but the exclusive presence of Th17 (producing @entity4155 , @entity4654 , @entity13236 ) and Th17/ @entity1198 (producing @entity4155 , @entity4654 , @entity13236 and @entity379 ) cells was found in the decidua of @entity7992 . More importantly, we observed that Th17/Th2 cells were exclusively present at the embryo implantation site during tubal ectopic pregnancy, and that @entity3646 , @entity9388 , @entity4155 , @entity9908 mRNA levels increased in tubal biopsies taken from embryo implantation sites, whereas Th17, Th17/ @entity1198 and @entity1198 cells are exclusively present apart from implantation sites. Moreover, soluble HLA-G5 mediates the development of Th17/Th2 cells by increasing @entity3646 , @entity4155 and @entity4654 protein and mRNA production of @entity404 + 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 @entity3646 . 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 implantation.
